SHIP INSTALLATION WITH THE RUDDER PROPELLER DRIVEN BY A GENERALLY HORIZONTAL SHAFT LINE TOGETHER WITH SPECIFIC JOINTS AND PROPELLER-SHAFT CARRIERS THERETO

Abstract: The shaft line includes a joint (5) before the propeller shaft (25) whereby the angularity of the latter is enabled with respect to the driving shaft (23). Besides the standard universal joints to be applied, a series of special gearbox and hydraulic joints have also been developed for the installation proposed. All of a multitude of propeller-shaft carriers (331) consist of the turning assembly (331T) and stationary assembly (331S) whose connecting and thus pivoting vertical axis coincides with the angularity axis V of the joint. Whereas the existing systems of ship steering with the rudder propeller (Schottel, etc.) have the shaft line "broken" several times in the elevation plan, the proposed installation is a "direct drive" with complete shafting lying in a horizontal line which makes the installation generally simpler, more reliable and capable of transmitting greater power ratings. In a series of cases the installation is a capsuled reducing-steering-propelling "compact" to be simply attached to or inserted into the ship's stern even while the ship is afloat.

Description: 1. Technical field to which the invention relates The invention relates to the field of ship propulsion and steering installations and it is particularly appropriate for the ships having need of an increased steering capability. 2. Definition of the technical problem The problem solved is that of ship steering by means of the "rudder propeller" which, in the case considered, is applied to the direct drive of ship implying that the shaft line is generally horizontal, i. e. that the usual vertical "stem" of the Z-drive is eliminated and substituted by an adequately sealed joint. 3. Prior art There is a general need to improve the steering of ships. This requirement is, however, particularly acute with pushboats, tugs, trawlers, ferries and a number of workboats. Lately, to increase the steering capability, there has been introduced the Z-drive (Schottel, etc.) with the engine mounted on the deck and the shaft line "broken" twice at right angles - firstly at the upper and secondly at the lower bevel-gear reduction gearboxes; Hook (Cardan) joints, splines, etc. are also built in the shaft line. The steering of the Z-drive is very good ("positive" steering by the "rudder propeller", no rudders proper are necessary) and the high-speed engines are applicable which both is useful, - but the shaft line has become complicated and rather vulnerable (instead of in the eliminated rudders, the complexity and vulnerability exist now in the shafting). Besides, only relatively small and light engines can be installed on the ship's deck. When installing a heavier engine in the machinery room, then the transmission is first conveyed on the deck (or below it) by a belt drive or by an obliquely positioned joint shaft and then there ensues the "leg" of the Z-drive (vertical shaft in the "stem" (tube) between the two gearboxes followed by a horizontal propeller shaft in its gondola) - which all is again complicated. For a better comparison and discussion, some additional features of the state of the art will be presented only after the present invention has been disclosed. 4. Disclosure of the invention With the reference to the drawings, the invention will be described hereinbelow. 4.1. List and brief description of the drawings Fig. 1 - General lay-out of the installation proposed with the joint 5 in the shaft line before the propeller shaft 25 ("first variant" for joint 5 being a universal joint 5U). Fig. 2 - a = side view at the joint 5, propeller shaft bearing 34, curved lever 33 and stock 3; b = plan view, propeller shaft 25 deflected by the pivoting (steering) angle α . Fig. 3 - A general presentation of the propeller-shaft carrier (PSC) 331 with its axis of pivoting (turning) V₃₃₁ = V₅ = V . Figs. 4, 5, 6, 7 - Various kinds of the PSC 331. Fig. 8 - Rudder 31 as the carrier 331. Fig. 9 - The universal joint 5U encompassed by the boot seal 555 and its shields 571, 572. Fig. 10 - Gear joint 5G in the one-part stationary housing 55 with the aft "window" 550A ("second variant"). Fig. 11 - Gear joint 5G in the two-part housing (part 551 stationary, part 552 pivoting) with the vertical seals 62M ("third variant"). Fig. 12 - Gear joint 5G in the one-part pivoting housing with the forward "window" 550F ("fourth variant"). Fig. 13 - Review of variants; a - 1st var. (universal joint 5U); b - 2nd var.; c, d, e - 3rd variants, versions forward-aft, lower-upper and upper-lower, resp.; f - 4th var. [b, c, d, e, f with gear joint 5G]; g - 5th var. (hydraulic joint 5H); h, i - 3rd and 4th variants with the joint protector 151, resp. Fig. 14 - Arced plate 6 with spring 61 and seal 62 in guides 56i, 56e. Fig. 15 - Angular widths of the aft window 550A, guides 56, etc., IGA = inter-guide access. Fig. 16 - Sealing of the aft window 550A by the riding band 6BR. Fig. 17 - a = equatorial seals 62E of the riding band 6BR with chamber 62i filled with header-tank oil; b, c = entry seals ES. [Next Figs. 18-24, 2nd var.] Fig. 18 - An embodiment of the 2nd variant; sealing by the arced plate 6 and boot seals 68, access tube 165 oblique. Fig. 19 - Tunnel 55T with the quasi stern tube 24Q; curved levers 33, 33L connected to the housing-born pins 541, 541L, RSPC. Fig. 20 - As in Fig. 19 but with engine 2 on the forward extension FE, semi-MRSPC. Fig. 21 - Ways of sealing tunnel 55T. Fig. 22 - An embodiment; curved lever 33 connected to the riding band 6BR which carries also the gear wheel G n , vertical access. Fig. 23 - Horizontal ring RG in the guides GRG carrying the joint's horizontal shaft 25i, access oblique. Fig. 24 - Arm 3A of the joint stock 51 carrying the hollow shaft 25. [Next Figs. 25-38, 3rd var.; Figs. 25-35, version forward-aft] Figs. 25, 26, 27 - Sketches of the 3rd variant: external, medium and internal supporting of the joint's horizontal shaft 25i, resp. Fig. 28 - Bearing 52 connected to the pivoting housing part 552; part connecting pins 5512, 5512L. Fig. 29 - Inter-part chamber 55i filled with oil from the header tank HT. Fig. 30 - Entry boot seal 555 and its protector 571 with the seal 571s. Figs. 31, 32 - Sealing of the joint protector 151. Figs. 33, 34 - Two embodiments of the 3rd variant; sealing near MMP, joint protector 151, flexible coupling 292, oblique access, etc. (extensive description in text). Fig. 35 - Stationary calotte 551 tunneled, no axis displacement, RSPC. Figs. 36, 37 - Versions upper-lower, access oblique. Fig. 38 - Version lower-upper, no access. Fig. 39 - An example of the "fourth variant"; forward window 550F, window protector 171F, boot seal 174F. Fig. 40 - 3rd variant, version lower-upper; horizontal ring RG, lowering tube connection, access vertical, RSPC. [Next Figs. 41-43, 52, 54-56 hermafrodite designs of RSPCs] Fig. 41 - Hermafrodite design (2nd & 3rd variant); stationary vertical tube 55V (part 551) and riding band 6BR (part 552) extended upward, stern tube 24 in guide 24G. Fig. 42 - Basically as in Fig. 41 but with the stern tube 24 structural (outside-hull case), jacket 33J, etc. Fig. 43 - Vertical tube 552 pivoting in the short tube 551 on the stool ST. [Next Figs. 44-48, 5th var.] Fig. 44 - Hydraulic centrifugal joint, "fifth variant" Figs. 45, 46 - Hydraulic multisphere friction joint. Fig. 47 - Hydraulic cylindrical whirl coupling. Fig. 48 - Hydraulic sphere whirl joint. Fig. 49 - V-drive with horizontal propeller shaft 25. Fig. 50 - Gear joint 5G with the secondary set of transmission elements (gears G₁'',...,G n ''). Fig. 51 - System protectors 191F and 191A (forward outer and aft inner, resp.). Fig. 52 - Version for larger ships, inner and outer housings (55V and 55D, resp.), riding band 6BR (552), tunnel 55T, etc. Fig. 53 - Easily substitutable RGJ 5G in cage CG. Fig. 54 - "Capsular embodiment" of the RGJ. Fig. 55, 56 - Two cases of the capsular embodiment (reversibility; f lexible c ouplings both at i nput and o utput of the joint, FCI=CG₁ and FCO=292, resp.). Fig. 57 - Satellite gears cylindrical. Fig. 58,a,b,c - Substitution of RSPC while the ship is afloat (for "compacts" with horizontal tunnel). Fig. 59 - General substitution of RSPC when the ship is afloat (cone-shaped connecting element 55E, etc.). Fig. 60 - An embodiment, substitution of RSPC as in Fig. 59. Fig. 61 - Strut STR and strut bearing 244 arrangement. Fig. 62 - Substitution of RSPC while the ship is afloat in the case of the strut bearing arrangement. Fig. 63 - The joint of Questiaux. 4.2. Abbreviations used CP = central plane (of ship); EP = equatorial plane (of joint); MMP = main meridional plane (of joint); MRSPC = motoring-reducing-steering-propelling "compact"; PSC = propeller-shaft carrier; RGJ = reduction gear joint; RSPC = reducing-steering-propelling "compact". 4.3. Description of the invention The Z-drive is fundamentally opposed to the "elementary rule" of the ship drive which is based on the fact that the engine crankshaft is generally horizontal, that the propeller shaft is also horizontal and that therefore the intermediate shafting connecting them (in fact, the whole shaft line) should be horizontal as well. It is exactly the "leg" of the Z-drive (in fact, its vertical "stem" only) that, on one hand, "hurts" the "elementary rule" and that, on the other one, provides a very good steering with the Z-drive. Therefore, the technical problem and engineering task posed are as follows: How to avoid the vertical "leg" (its "stem") and thus meet the "elementary rule" and thereby still achieve as good a steering as with the Z-drive ? The answer reads: As shown in Fig. 1, an engine 2 is put on the floor of the machinery room of ship 1 and then a normal generally horizontal shaft line is installed and let, as usual, to pass through the stern tube 24 but - which is essential - with a joint 5 being built into it just after the stern tube 24 (or just after the strut bearing) and a specific carrier 331 of the propeller shaft 25 being fitted to the ship's stern 11 (in one embodiment, in Figs. 1 and 2, that carrier consists of the propeller-shaft bearing 34, curved lever 33 and stock 3 in bearings 36, 37 in the structural tube 35). The specifics of the carrier 331 lies in the fact that, on one hand, it holds firmly (in an unyielding way) the propeller shaft 25 and propeller 26 and, on the other one, enables their pivoting (turning) by the steering angle ± α owing to the fact that - which is also essential - the carrier's 331 axis V₃₃₁ (stock's 3 axis V₃) of pivoting coincides with the joint's 5 pivoting axis V₅, V₃₃₁ = V₃ = V₅ = V = common axis . [To note is also that the propeller-shaft bearing 34 is provided with the thrust collar 342 and that the stock 3 is turned by the steering gear 32; skeg 121 and fins 122, 122L are useful but not essential for the "answer".] This basic "answer" gets into the class of simple "classical direct drives" of ship (where the whole shaft line is horizontal) - but now, which is novel to that class, with the propeller being a "rudder" propeller ("active" steering). To note is that the "confrontation" of two seemingly controversial systems - rudder propeller on one hand and classical direct drive with a horizontal shaft line on the other one - is enabled here by a joint 5 being fitted in the shaft line outside the ship's hull. In other words, now we have a class of "joint-enabled rudder propellers" (briefly, of "joint rudder propellers") versus the already classical class of "vertical-shaft rudder propellers" (Z-drive). As a matter of course, the basic solution presented can be elaborated in a multitude of ways regarding both the joint 5 and propeller-shaft carrier (PSC) 331. Thus, the joint 5 may be a standard universal homokinetic (commercially available mechanical) joint 5U (as in Figs. 1 and 2), a gearbox joint 5G (to be proposed here), an hydraulic joint 5H (to be also proposed here), an electro-magnetic joint 5E, etc. while also the PSCs 331 can be designed in a multitude of ways. The universal homokinetic joints 5U are not suitable for the transmission of greater power ratings and therefore their use is necessarily restricted to the smaller craft only (pleasure boats, patrol craft, etc.). Their application in ship rudder-propeller drive is covered by patents of Kilvington (USA 2956536), Le Louer (Fr 1023513), Parish (USA 3430603), de Karavenant (Fr 2003041), Harris (GB 1353184), Ross (USA 3919965) and Connor (UK 2092973). A practical application of the universal homokinetic joint 5U is also the so-called "Arneson drive" where the propeller shaft following the joint is supported by two obliquely aftward positioned hydraulic cylinders fixed to the stern (transom) 11 of boat so that the steering is performed by extending and contracting the said cylinders. The gear joints 5G are applicable generally (both to small craft and large vessels) and therefore they are very significant for the field in hand. Moreover, they are inherently "reduction" gearboxes which is also very appropriate for ship driving systems. The application of the gear joints in ship driving is covered by the French patents by Questiaux (Fr 1156779), Barrère (Fr 618319), Lefebvre (Fr 645087) and Basset (Fr 637613). As far as the author is aware, the hydraulic (5H) and electro-magnetic (5E) joints have not been proposed for the ship drive so far. They are applicable to high-speed propellers mainly (which propellers, on their part, are fit for the smaller and fast craft only). The oldest patent in the field of joint rudder propellers seems to be the German patent by Dietrich (De 5120). A specific (non-standard) universal joint is applied there with the propeller-shaft carrier which is appropriate mainly for large vessels. In the present patent application, we elaborate our basic concept - which is to cancel the vertical "stem" and thus to get a ship installation with the whole shaft line being generally horizontal, i.e. to get a "joint rudder propeller" installation, - and, in doing so, we first concentrate on the design and application of the reduction gear joints 5G (since we start by opposing to the Z-drive where also the gearboxes are applied) and then, following the same basic line of thought, we develop and apply also the hydraulic joints 5H which fit very well to the said basic concept. Hence, the universal homokinetic joints 5U are used here only as an introduction to the field (however, some propeller-shaft carriers 331 developed for the other joints may be applied to these joints, too) while the emphasis is necessarily on the use of the reduction gear joints 5G and hydraulic joints 5H. For the reasons of installing it appropriately and for a general suitability for and efficiency in the ship drive, the reduction gear joint 5G to be proposed here will be necessarily located in a single and compact housing (both properties are important), preferably in a streamline shape. This is in a sharp contrast to the gear joints proposed in the said patents of Barrere, Lefebvre and Basset where the gear joint is located in two or three separate housings (so that, actually, several joints perform the duty of a single joint needed; such combined joints, located in two or more separate housings, might be called the "joint complexes "). The requirement of a single compact housing asks for a special "condensed" design of the interior of the joint (specific disposition and supporting of shafts and gears within the joint, specific sealing, etc.) which will be elaborated in more detail later. The only gear joint in a single and compact housing proposed so far in the rudder-propeller drive is that of Questiaux (Fr 1156779), Fig. 63, - which, however, turned out to be abortive and which also will be discussed at a later stage (see Art. 4.4). As for the propeller-shaft carrier 331, it consists generally (see illustrative Fig. 3) of its pivoting (turning) assembly 331T (propeller-shaft bearing 34, curved lever 33 and stock 3 in Figs. 1 and 2) and stationary assembly 331S (bearings 36, 37 and tube 35 in Figs. 1 and 2) with its axis V₃₃₁ of pivoting necessarily coinciding with the joint's axis V₅. Another implementation of the PSC 331 is shown in Fig. 4 where it consists of the curved lever 33 that is provided with the hub 330 pivoting around the pin 111 fixed in the stern 11 (pin 111 may be extended and have the upper bearing 1191 which is represented by dotted lines; elements 34, 33, 330 and 111, 1191 belong to the pivoting and stationary assemblies 331T and 331S, resp.). The pin 111 and steering gear 32 (M is the meshing of the steering gear 32 with hub 330) are located in the well 116 provided with the window 110 through which the curved lever 33 gets out of the well. Next step is the pin 111 supported by a strong cantelever beam 119 protruding from the stern 11, cf. Fig. 5 (the tiller 3301 and ram 321 are in the well 116 but there is a protector 1162 with seal 1163 that closes the well 116 and keeps it dry; dotted lines present the extension of the pin 111 and its upper bearing 1191). [Note: Generally, since consisting of several elements, the propeller-shaft carrier 331 is not explicitly denoted in the figures to follow; exceptions to this are made only in Figs. 1, 2, 4 and 8. Textual comments regarding the PSC 331 (its assemblies 331T and 331S) are, however, given almost for all figures.] A further example of the PSC 331 is given in Fig. 6 where besides the curved lever 33 and its hub 330 there is the pin 241 fixed to the arm 242 which is just an extension of the stern tube 24 (the arm 242 is shrunk on the stern tube). The nearby steering gear 32 is fitted also to the stationary arm 242 (or to the pin 241 itself). Further on, in Fig. 7 there are the lower curved lever 33L, its hub 330L, pin 241L and arm 242L which are "parallel" to the upper ones 33, 330, 241, 242, respectively. The steering gear 32, located in the dry compartment 116, is connected to the hub 330 of the upper pin 241 by a short vertical stock 3 and a double slider or similar coupling 513 (311 is the seal of the stock 3). (This PSC is similar to that of Dietrich (De 5120), the difference being in the fact that the arms 242, 242L are supported by the stern tube 24 rather than being derived from the sternpost.) It will be seen later that there are also the designs with pins 541 (for hubs 330) on the very joint's housing 55 (Figs. 19, 20, etc.), whereby that housing gets to be included into the PSC 331. However, the discussion of the multitude of PSCs 331 will be temporarily interrupted here by noting only the fact that also the usual rudder 31 with its stock 3 can be transformed into the carrier 331 of the propeller shaft 25 inasmuch as it accomodates the joint 5 in its lower forward corner and "receives" within itself the generally horizontal propeller-shaft bearing 34, cf. Fig. 8. [To note is that the pins 111, 241,... and hubs 330,... - as well as their equivalents to appear in the further discussion - can exchange their carriers. For example, the pins may be fixed to the curved levers 33, 33L,... (and thus belong to the pivoting assembly 331T) while hubs, turned into bearings, may be fixed to the (earlier pins') stationary carriers (and thus belong to the stationary assembly 331S of the PSC 331.] With the designs in Figs. 1, 2, 4, 5 and 8 the propeller 26 is - through the PSC 331 - supported by the stern 11 of ship ("stern-supported" propellers). With the designs in Figs. 6 and 7 the PSC 331 is such (it includes the pin 241 on the arm 242 of the stern tube 24) that the propeller is supported by the stern tube 24 ("stern-tube supported" propellers; most of the announced designs where the housing 55 is included into the PSC 331 belong to this group). Mixed solutions are possible as well. Stern-tube supported propellers are very convenient regarding the alignment of the shaft line. Note should be made that the propeller shaft 25 in Figs. 1 through 8 is relatively short, that it is almost completely situated in the casing of the propeller shaft bearing 34 held by the curved levers 33, 33L and that therefore it is well protected. A substitution of the levers 33, 33L by a strong closed cone-shaped jacket 33J to be made later (Figs. 23, 38, 42, etc.) will yield a complete protection to that shaft. The universal joints 5U applicable in the installation described are the well-known homokinetic universal joints which are generally available. The only additional requirement for the homokinetic universal joints 5U when applied in the described ship installation relates to a better sealing (surrounding water should not enter the joint) and this is a requirement that can be met in a satisfactory fashion (a similar situation is met in sealing the hubs of controllable pitch propellers where the problem of sealing has been satisfactorily solved). A simple sealing of the universal joint in our application is presented in Fig. 9 where the joint 5U is embraced by the boot seal 555 (containing grease) which is fixed to the driving and propeller shafts 23 and 25, respectively. Besides, there are the (partially overlapping) spheric shields 551 and 572 which are fixed to the said shafts and which protect the boot seal 555 from the streaming surrounding water, floating debris, etc. (the shields 571 and 572 are not necessarily mutually sealed). Hence, both the universal homokinetic joint 5U itself and its housinglike protector consisting of the shields 571 and 571 are completely carried by and revolving with the driving and driven (propeller) shafts, respectively, - to be called the "joint's shafts". In other words, there is no (stationary) housing proper whose basic duty would be to carry the joint and only then to protect it. In this text, the application of the universal joint 5U will be called the first variant of the installation. This variant as such is not considered to be novel and it serves here only for a general introduction to the subject matter. An overview of variants is given in Fig. 13 where Fig. 13,a relates to the 1st variant. Note should be made that the universal homokinetic joints possess an infinity of axes with respect to which the two shafts connected can be "broken" (angularity or pivoting axes). This is much more than necessary in our application where basically only one (vertical) axis of angularity is needed. The above fact induces us to design "simple (non-universal) joints" possessing only one (vertical) axis of angularity. Therefore, two groups of new joints will be proposed here. The first group consists of mechanical "reduction gear joints" 5G (the second, third and fourth variants of the installation, Figs, 10, 11, 12, resp., and 13,b-f) while the second one includes hydraulic joints 5H (the fifth variant of the installation, Fig. 13,g). As a matter of fact, the first group (gear joints) yields strictly simple joints while the second group (hydraulic joints) offers inherently universal joints which will be used here mostly as simple joints. The basic version of the reduction gear joint 5G consists of the following: In the joint's transmission line containing gears (and eventually other transmission elements) there is the first bevel gear G₁ which is vertical and is fixed to (or meshed with) the horizontal driving shaft 23 getting out of the stern tube 24, cf. Fig. 10. The said gear G₁ is followed by a train of transmission elements reducing, but not necessarily so, the speed of revolution. The last but one gear in the line is the horizontal bevel gear G n-1 whose axis V n-1 , around which a strong joint stock 51 is built up ( V n-1 = V₅₁ ), is vertical and coincides with the axis V₃ of the vertical stock 3 (of the PSC 331) and thus does so with the common axis V (V n-1 = V₅₁ = V₃ = V₃₃₁ = V) . The last bevel gear G n is vertical (hence, there are at least three bevel gears in the joint's transmission line) and it is directly meshed with the last but one bevel gear G n-1 in one meshing point G n-1 -G n (which may be either the uppermost or lowermost point of the gear G n - depending on the mutual position of the bevel gears G n and G n-1 ). As a rule, the horizontal axis of the last bevel gear G n coincides with the axis of the propeller shaft 25 supported by the propeller-shaft bearing 34 that is linked (by the curved lever 33) to the stock 3. The bearing 52 close to the last bevel gear G n - in fact, the bearing of the joint's horizontal shaft 25i carrying that gear - is supported by the joint stock 51 by means of a curved arm 53 and bearing 54 (or otherwise) in the way that it can be pivoted (turned) around the joint stock. [Note: The propeller shaft 25 and joint's horizontal shaft 25i may be connected directly or through a spline 255 or they may be even made as a single propeller shaft. In all of these cases they keep being coaxial and therefore will be jointly called the "propeller shafting". Therefore, by the propeller shafting will be understood both of these shafts if both of them are existing and only the propeller shaft if only that shaft is existing.] The train of gears and transmission elements described (i.e., the whole transmission line of the joint) is necessarily enclosed in a single compact housing (casing) 55 shrunk on the stern tube 24 (or otherwise fixed to the ship's stern). The problem of the propeller shafting 25,25i getting out of that housing (in a necessarily sealed way) to perform its steering pivoting will be discussed at a later stage. The gear assembly presented is a "simple joint" acceptable in our application. For, the axis V₅₁ of the joint stock 51 is actually the vertical axis V₅ of the joint 5G with respect to which the axes of the incoming driving shaft 23 and outcoming propeller shafting 25,25i realize the joint angle ± α when, in the steering turning, the propeller shafting travels (gets deflected) in its horizontal plane by pivoting with respect to the axis V₅₁ of the joint stock 51. Let us, however, note the following. The meshing points of gears G₁,..., G n-3 , G n-2 of the train of gears are invariable while the meshing point, G n-1 -G n of the last but one bevel gear G n-1 with the last bevel gear G n travels in the steering turning on the circumference of the pitch diameter of the horizontal last but one bevel gear G n-1 . In other words, in the steering turning the last bevel gear G n undergoes an additional rotation (positive or negative - depending on the direction of the steering angle α ) as against the gear G n-1 , which rotation is superimposed on the regular (driving) rotation (to note is that the same phenomenon exists in the lower gearbox of the Z-drive). However, this additional ("steering") rotation is less than 0.5% of the regular (driving) rotation so that it may be neglected. [Notes: (a) While the transmission ratio r of the (mean) speed of the incoming shaft versus the speed of the outcoming shaft with the universal homokinetic joints 5U is r u ≡ 1, with the simple gear joint 5G proposed it can be r g 1 (with r g being a constant or, if need be for a greater flexibility of operation, several constants); (b) Depending on the design, the angularity with the universal joints 5U is theoretically limited to 15 o - 30 o and, besides, with an (operationally) increasing angularity the driven shaft undergoes an increasing nonuniformity as against the driving shaft revolving uniformly; in contrast, with the simple gear joint 5G proposed there is no (theoretical) limit to the angularity (in the horizontal plane) and, in addition, the driven shaft follows exactly (in a constant speed ratio) the driving one.] Needless to say, besides their function as joints, the simple gear joints described are also the reduction gears (r g >1) or gearboxes (and even, if need be, the reverse reduction gears) which is very convenient since in the rudder-propeller drive there is mostly a need for r g = 3 - 6. To point to both of the said functions, we shall call them the reduction g ear joints (RGJ) or g earbox joints (which, after all, are the terms that have already been used here). As already noted, the gear joint variants are necessarily the "housing variants". Basically, there are three ways to design their single compact housing 55 and thus to fit the RGJ 5G in a suitable way into the ship installation: The housing 55 is a unique (one part) casing that is shrunk on the stern tube 24 and possibly connected to the stern 11 of ship (by attachment 159) so that it is stationary, see Figs. 10, 13,b, 18. In this case the housing must be provided with a sealed aft horizontal slot or port or "window" 550A to allow the propeller shafting 25,25i to get out of it and perform its steering turning by pivoting around the common axis V. Hence, this is the case of the "stationary one-part housing with the sealed aft window" - to be referred to as the second variant of the installation. The housing is a two-part casing with the dividing plane being either the medium vertical transverse plane (main meridional plane, MMP) or one of the horizontal planes, preferably the medium one (equatorial plane, EP). The part that is fixed to the stern tube 24 (in general, to the ship's stern 11) is the "stationary part" 551, the other part is riding on it and that is the "pivoting (turning) part" 552 (its pivoting axis V₅₅₂ coincides with the common axis V) while the propeller shafting 25,25i is passed "normally" (without a "window") through it since they pivot together; thus, by considering the position of parts and naming first the stationary part 551, there are either the versions forward-aft (MMP-sealed versions with vertical seals 62M), Figs. 11, 13,c, 25-28, 33-35; or versions lower-upper , Figs. 13,d, 38, 40; or versions upper-lower , Figs. 13,e, 36, 37 (the latter two versions being the EP-sealed versions with horizontal seals 62E). Hence, this is the case of the "two-part housing with the part sealing in or near the dividing plane (and no "window sealing" of the propeller shafting)" - to be called the third variant of the installation. [Notes: (1) Under circumstances, the dividing plane may also be an oblique plane more or less close to either the MMP or EP or it may be just in between; (2) Generally, the stationary housing part 551 and pivoting part 552 may be either the inner and outer parts or vice versa.] The housing 55 is again a unique (one-part) housing which, however, is connected (by attachment 335) to the curved lever 33 (in general, to the PSC's 331 pivoting assembly 331T) and thus pivots with it around the common axis V, see Figs. 12, 13,f, 39. In this case the housing is provided with a horizontal sealed forward "window" 550F to be able to ride (in the steering turning) across the incoming driving shaft 23 which is revolving but stationary in space. Hence, this is the case of the "pivoting one part housing with the sealed forward window" - to be denoted as the fourth variant of the installation. Let us first discuss the 2nd variant . The only real problem with the 2nd variant (Figs. 10, 13,b, 18) is the sealing of its aft window 550A. By allowing for the radius of the propeller shafting, the angular width ± α w of the window 550A should be by a small amount (by ±β₁ ≈ ±10°, say) greater than ± α m = maximum steering angle of the propeller shafting (which amounts to ≈ ±(35°-40°)), ± α w = ±( α m +β₁) , Fig. 15. One of a multitude of ways to seal the window 550A of such an angular width is by the rigid vertical plate formed (in the horizontal plane) as a circular arc (whose center is in the joint stock axis V₅₁ = V₅ = V ) to be called the arced plate 6, Fig. 14, which plate embraces (by its sealed collar 60) the propeller shafting 25,25i and travels with it in the circular guides 56 (56i = internal guide, 56e = external guide or housing wall) by the steering (turning, deflection, pivoting) angle ± α m . The angle widths ± α ₆ of the circular-arc plate 6 and ± α ₅₆ of the guides 56 are by ±β₁' greater than ±2 α m and ±3 α m , hence ± α₆ = ±(2 α m +β₁') and ± α ₅₆ = ±(3 α m +β₁') , respectively, Fig. 15. (β₁' is by Δβ greater than β₁ to allow for the width Δβ = β₁'-β₁ of the seal around the vertical rim of the window 550A.) The arced plate 6 is pressed by the stationary spring 61 against the seal 62 circumventing the window 550A. The said seal is fixed to the housing wall 56e, which wall - while being in the equatorial region of the housing - is (just as the plate 6 itself) circular in plan and vertical in elevation. In a variation, the springs may be fixed to the arced plate 6 and travel with it. In general, there is a number of seals and "springs" that may be applied here (including the inflated hoses, the Newark seals, radial face mechanical seals, etc., which are both at the same time - hence, "springy" seals - and as such are selfadjustable). If necessary, more than one seal or springy seal may be on both sides of the arced plate 6 with the chambers between the seals filled with overhead tank oil. Also, there may be two or more arced plates 6, etc. If the guides are made as complete horizontal circles then a full-circle riding band 6BR (short vertical turning tube riding on the tubular housing) is used instead of the arced plate 6 and also the full-circle (circular) standard Simmer rings (lip rings), O-rings, etc. 62E are used instead of the seal 62, cf. Fig. 16 (the band and guides may be either external or internal to the housing or both - with the chamber in between filled with oil; in Fig. 16 they are external). With the riding band 6BR, the "seal range" consisting of the upper and lower riding-band guides (seats) 6SU and 6SL and one or more upper and lower horizontal seal rings 62EU and 62EL located above and below the propeller shafting 25,25i, resp., together with the riding-band 6BR and guides, - should not interfer with the range of the driving shaft 23, that is, there should be an either positive or negative axis displacement a (axis of the propeller shafting 25,25i should be either above or below the axis of the driving shaft 23, a >0 or a <0, respectively). The arced plate 6 or riding band (tube) 6BR are actually covers to the window 550A and therefore will be jointly called the "window covers". In Fig. 17,a there is presented the lower end of the riding band 6BR with its guide (seat) 6SL and two seal rings 62E in their chamber 62SC (by conduit 6CB, the inter-seal chamber 62i is filled with header tank oil). For the sealing of the very entry to the seal chamber 62SC there is a collar ES of polymer, hard rubber or similar material, which collar is radially slightly elastic so that the spring 6S tightens it to the housing 55. Thus, the sealing is quadruple: by the collar ES, by seal rings 62E, by header-tank oil (conduit 6CB) and by the very seat 6SL. The collar ES as an entry seal may be applied generally. If the stationary and pivoting parts 551 and 552, respectively, are close to one another, then the entry seals ES may be made as in Figs. 17,b,c or in any other appropriate way. In Fig. 18 there is presented one of a multitude of embodiments of the 2nd variant. The one-part housing 55 is shrunk on the stern tube 24 and, by the oblique access tube 165, connected also (by attachment 159) to the stern 11 of ship. Its aft window 550A is sealed with the arced plate 6; there are also seal 62, spring 61 and collar 60. Besides, there are two sets of internal boot seals 68 with collars 660 and plates 606 and 607. The joint 5G consists of the joint stock 51 and bevel gears G₁, G₂-G₃ and G₄ supported by the driving shaft 23, joint stock 51 and joint's horizontal shaft 25i, resp. so that there is a double reduction of the speed of revolution. The axes of the joint stock 51 and stock 3 necessarily coincide with the common axis V. The joint's horizontal shaft 25i is supported by two roller bearings in the bush 514 whereby the bearing 522 is formed that is built in the joint stock 51 (which means that the matter is about the "internally supported" gear wheel G₄, cf. Fig. 27 and the relevant text). The aft end of the joint's horizontal shaft 25i supports the flexible coupling 292 that connects it to the propeller shaft 25. The PSC's 331 pivoting assembly 331T consists of the curved lever 33 and stock 3. While in the steering turning the pivoting assembly of the joint (consisting of elements 51, 514 (522), 25i, G₄, 292) is basically pivoted (deflected) by the propeller shaft 25 through the flexible coupling 292, a more direct pivoting is performed by the joint stock arm 517 which is coupled to the curved lever 33 by the plate 531 in the guides 532 whereby the lagging of the pivoting assembly of the joint due to the compliance angle of the flexible coupling 292 is forestalled. The oil bath in the bottom of the housing serves for lubrication of gears and bearings (forced lubrication may be applied as well). Partition 293 protects the flexible coupling 292 from oil splashing. The fan 294 cools the rubber parts of the flexible coupling 292 (the heat is transmitted to the surrounding water). Bilge 7 is drained by the bilge pipe. Another version of the 2nd variant is presented in Fig. 19 where the housing 55 is provided with a horizontal forward tunnel 55T that is inserted in the tunnel's guide 55TG in the stern (transom) 11 and fixed there. In the lower portion of the tunnel there is a quasi "stern tube" 24Q with its bearings BA and BF (or, instead, two "open" bearings without the tube) supporting the driving shaft 23. (The tube 24Q is located within the tunnel 55T so that it is not, as usual, a structural part of the stern 11 directly wherefrom we call it the "quasi" stern tube.) If the tunnel's guide 55TG and the engine foundation are well aligned then the driving shaft 23 and the forward part of the shaft line are connected by an ordinary coupling (or by a spline). Otherwise, for alignment reasons, they may be connected by either a flexible coupling or a joint (working practically with a zero angularity) or, as in Fig. 19, a short shaft 23S with fast gear couplings GC at its ends. In Fig. 19, the housing 55 and its tunnel 55T belong to the stationary assembly 331S of the PSC 331 since the pins 541, 54lL on the very housing support the curved levers 33, 33L and thus receive the propeller's both weight and thrust force and transmit them through the housing 55 to the ship's stern 11. Hence, this is the case of the "stern supported propeller" but with the joint housing 55 being included into the PSC 331. To note is that this version is very practical since the whole installation (both the RGJ 5G and the propeller 26 with the complete PSC 331) is a compact unit to be simply (horizontally, axially) inserted (slid like a drawer) into the ship's stern 11 (substitution of a damaged unit by a new one is very quick). Besides, there is an ample horizontal access 160 enabling major repairs of the gearbox to be done with the ship afloat. Besides bringing forth the easiness of mounting and dismounting, the compactness mentioned implies also that the whole unit is produced, adjusted and aligned in works with very little left to be done aboard the ship. Such compact units emerge as soon as the housing 55 (or its stationary part 551) gets included in the stationary assembly 331S of the PSC 331 (by introducing the pins 541, 541L fixed onto the housing 55 or otherwise). Since the compact units in hand include a reduction gear, a steering gear (basically, the joint-stock pivoting assembly) and a propeller - they will be called the reducing-steering-propelling "compacts" (RSPC). Besides the very compactness, the main characteristic of the RSPCs is their easiness of mounting and dismounting. For smaller ships with high-speed engines (which are both small and light), the RSPC may contain also the engine itself that is fitted on the lower tunnel plate in front of the quasi stern tube 24Q or, if the latter is omitted, in front of the RGJ. In this case, evidently, there is no problem of shaft alignment within the ship since the whole shaft line including the engine is contained in the compact (in its tunnel 55T), which compact - since performing also the motoring - will be called the motoring-reducing-steering-propelling "compact" (MRSPC). (The motor may be an internal combustion engine, an electric or hydraulic motor, etc.). Hence, the RSPCs and MRSPCs with the horizontal tunnel 55T are actually some kind of "capsules" (or "cartriges") to be inserted into the ship's stern to perform the functions indicated. (It will be seen soon that there are the RSPCs with oblique and vertical access tubes as well.) If the engine 2 - even though being a high-speed one and thus generally small and light - is still too large to be located within the compact's tunnel 55T (horizontal tube 165), then it may be fitted on the "open" forward extension (platform) FE of the lower side of the tunnel and mounted there only after the compact has been inserted into the hull (and dismounted before it is pulled out from the hull), Fig. 20. The concept that the whole shaft line including the engine and propeller at its ends is carried by a single structure (which is the structure of the "compact") so that the ship's hull is not involved in shaft alignment - is preserved here. Since this compact is an RSPC before being inserted into the stern to become an MRSPC only thereafter, it may be called the semi-MRSPC. The tunnel guide 55TG and other fixation should be standardized for a wide interchangeability of RSPCs or MRSPCs. The sealing of the tunneled compacts can be made in a number of ways: by seals SL (packings, inflatable hoses, etc.) pressed below the outward and inward attachments 159, Fig. 21,a; by the plate ring PR lightly welded to both the tunnel 55T (tube 165) and stern 11, Fig. 21,b; by seal SL at the forward end of the guide 55TG, Fig. 21,c; by some stuffing boxes; by filling the "chamber" between the tunnel and its guide with header tank fluid, etc. The next group of versions of the 2nd variant is obtained by making the stationary housing 55 as a strong vertical tube 55V protruding from the ship's stern 11 and possessing the aft window 550A while the curved levers 33, 33L (or their substitutes such as a cone, sleeve, etc. carrying the bearing 34 and embracing the shaft 25) are fixed to the strong window cover WC riding the tube 55V. Thus in Fig. 22 the "window cover" is the riding band 6BR that lies by its foot 6F on the circular foothold (seat) 6FH offered by the inner stationary tube 55V. The band (short outer tube) 6BR carries a strong horizontal bush 55BS whose forward end enters the tube (housing) 55V through its window 550A and yields there the bearing 52 to the joint's horizontal shaft 25i and gear G₄ while its aft end yields the bearing 52A to the shaft 25i and the forward half of the flexible coupling 292. The propeller-shaft bearing 34 and curved lever 33 carry the bush 34B which is shrunk on the aft end of the bush 55BS while the curved lever 33 itself is also fixed to the band (tube) 6BR which rides on the stationary tube 55V that is shrunk (by its bush 55B) on the stern tube 24 (elements 34, 33, 6BR, 55BS and 55V, 55B, 55t belong to the assemblies 331T and 331S, resp.) Thus, the stern tube 24 carries the weight of the cantilevered complex "gearbox joint plus propeller" while the clamping moment is offered both by the stern tube 24 and the structural tube 55S of the stern 11. Namely, the complex is horizontally shrunk on the stern tube 24 (the stern 11 is slightly sunk so as to receive thereby the forward upper end of the tube 55V) and then the intermediate tube 55t within the tube 55S is lowered down ("lowering tube connection") by being either screwed or shrunk or splined, etc. onto the tube 55V (so that, in some cases, the weight is partially born by the tube 55S, too). Thus, the vertical tube (housing) 55V is not strictly a structural part of the stern and therefore the mounting of the whole unit is easy - such that this is an RSPC with the vertical (upper) access 160. The gear wheels G₂ and G₂' in Fig. 22 are by their claws and sliding dog SD (which is actuated by the lever LV and hydraulic cylinder HC) intermittently coupled to the sleeve SLV whereby the reversing is performed. The steering gear 32 is fixed to the tube 55V and it meshes with the horizontal arced rack AR which is, through the upper window 550U, connected with the band 6BR (or, alternatively, which is through the pillar PL (dashed lines) connected with the forward end of the bush 55BS in which case there is nor upper window 550U). The seals 62EL and 62EU are O-rings (other seals are possible, too). The upper seal 62EU is additionally sealed with the entry seal ES. The hose 261 and distributing box 262 fitted to the face of the shaft 25i serve the mechanism of the controllable pitch propeller (which propeller is an alternative to the reversing mechanism by gears G₂, G₂'.) The version in Fig. 22 differs basically from the previous versions in the following: it is only the stationary housing 55 or 55V (belonging to the stationary assembly 331S) that has been supporting all the gears G₁, ..., G n (which were carried by the joint stock 51 located in the housing 55) while in Fig. 22 the last gear G₄ is being supported by the riding band 6BR (belonging to the pivoting assembly 331T). This implies that the dimensions a₁ and a₂ should be made very precisely since they affect directly the meshing of the gears G₄ and G₃ (a₁ + a₂ = a = displacement of axes of shafts 23 and 25i) . Also, the gliding surfaces of the foothold 6FH and foot 6F should be well both made and protected. To note is that the lower portion of the vertical tube 55V in Fig. 22 serves as the housing 55 to the gear joint 5G while its upper portion (its "upward extension") plays the role of the access tube 165 (which holds generally for the case of the vertical-tube housings). A somewhat different interior of the housing 55 (55V) than in the previous designs is presented in Fig. 23 where a horizontal ring RG is fitted in the circular or circular-arc guides GRG fixed to the inside of the cylindric housing 55 (the centers of the guides lie in the joint stock axis V₅₁ = V) while the ring contains the bearings BRF and BRA supporting the propeller shafting 25,25i that is passed through the arced plate 6 (or band 6BR). The propeller-shaft bearing 34 is fixed to the arced plate 6 (or band 6BR) by a rigid closed streamlining cone-shaped jacket 33J which is strong enough to receive and transmit to the housing 55 both the propeller's weight and thrust and which also turns out to be a good protection to the propeller shaft 25 (while the shafts 25i and 25 are connected by the flexible coupling 292). The steering gear 32 is meshed with the sector SC fixed to the ring RG. For reversing, the two "last" counter-rotating gears G₄ and G₄' freely revolve on the joint's horizontal shaft 25i and are intermittently meshed to it by the multidisk clutches MDC (claw and other clutches can also be applied; each of the gears G₄ and G₄' may have its clutch or a single clutch in between may serve both of them). The joint stock 51 is short now (it carries only the gears G₂ and G₃). Thus, in contrast to the previous cases, the joint's horizontal shaft 25i supporting the last gear(s) is not carried here by the joint stock 51 (as in the previous cases and those in Figs. 33, 34, 37. 40, 41, 43, 52, 53, 62 - to be therefore called the "joint-stock" versions of the joint) but is so by the said horizontal ring RG - for which reason the case of Fig. 23 (as well as that of Fig. 40) might be called the "horizontal-ring" version of the joint). To note in Fig. 23 is that, in order to reach reversibility, the joint's transmission train has been divided there (from the gear G n-1 onwards) into two reversely revolving subtrains (branches) ending with the counter-rotating gears G n , G n ' (n = 4). This, of course, may be applied generally with the branching point being on any transmission element before the last bevel gears (cf. Figs. 35, 55). By its bush 55B, the cylindric housing 55 in Fig. 23 is shrunk on the stern tube 24. Besides, its top is fixed (by a flange or similar coupling - to be generally called the "face connection" and designated by 158) to the stationary oblique tube 165 (with access 160) protruding from the stern 11 so that the whole unit is mounted very simply (bell-and-spigot and some other couplings may be used here, too). Hence, this is an RSPC with the oblique (forward upper) access where the elements 34, 33J, 6 and 55, 55B, 24 belong to the assemblies 331T and 331S, respectively. [Connections as by the vertical intermediate tube 55t in Fig. 22 ("lowering tube connection") or by the oblique (or other) tube as in Fig. 23 ("face connection" 158) can also be applied to a number of other RGJ-housings in order to achieve an RSPC.] In Fig. 24 the strong vertical joint stock 51 is provided with the horizontal arm (cantilever) 3A which carries the hollow propeller shaft 25 with the gear wheel G₄ and propeller 26. The shaft passes in the usual way through the arced plate 6 (or riding band 6BR). The joint stock 51 is supported by the strong bearings 5BL and 5BU in the housing 55 that is shrunk on the stern tube 24 and attached to the stern 11 by the tube 165. The steering gear 32 fitted in the housing turns the stock 51 by the quadrant SC. The bearing 52H in the propeller's hub is both axial and radial such that the thrust is transmitted through the arm 3A to the joint stock 51 and the housing 55 (thus, the elements 3A, 51 and 55, 24, 165 belong to the assemblies 331T and 331S, resp.). The gear G₄ is splined to the shaft 25 so that the thrust does not affect the meshing point of the gear G₄ with gear G₃. If the housing is connected to the tube 165 by a flange or similar face coupling 158 (as in Fig. 23) then the arrangement is an RSPC. The joint stock 51 may be extended into the stock 3 supported by the structural tube 35, the stock 3 being provided with the curved lever 33 carrying the propeller-shaft bearing 34 (dashed lines). (In the latter case the arrangement ceases to be an RSPC.) Now, let us discuss the case of the third (or two-part housing) variant of the installation. Here, the discussion of the 3rd variant will at first be conducted for the forward-aft (MMP-sealed) versions of the variant with the housing parts 551 and 552 being the inner stationary and outer pivoting calottes, respectively, cf. Figs. 11, 13,c, 33, 34, but it will generally hold for the other versions, too. [Usually, a calotte is less than a semisphere. Here, however, we use "deep calottes" which are somewhat more than semispheres so that they partly overlap each other at α m .] Before tackling the basic problem of the 3rd variant - which is that of sealing the two housing parts - let us discuss the problem of supporting the joint's horizontal shaft 25i with the last bevel gear wheel G n on it (which problem relates to the very RGJ 5G irrespective of the variant, but is emphasised here because of the relative motion of the two housing parts). Namely, it has already been shown that the out-of-joint-stock bearing 52 of the joint's horizontal shaft 25i is supported by the joint stock 51 by means of the curved arm 53 and bearing 54 so that it can pivot either around or with the joint stock (in the case of the joint stock 51 being non-pivotal or pivotal, respectively), cf. Fig. 11. There are, however, some additional solutions, too. Thus, first of all, there may be two curved arms (or some brackets or the like) and their bearings, the upper ones 53 and 54 and the lower ones 53L and 54L, resp., cf. Fig. 25 (in Figs. 25-28, G n = G₄ ). The joint stock 51 is the basic supporter of all of them. Then, the hub 520 of the gear wheel G n (of the shaft 25i) may be supported by the pin 521 that is carried by the joint stock 51, cf. Fig. 26 (so that the hub-520 complex plays the role of the bearing 52). Thereupon, the bearing of the joint's horizontal shaft 25i carrying the gear G n may be built in the very joint stock 51, cf. Fig. 27, in which case - being an in-joint-stock bearing - it is denoted by 522. In Figs. 26 and 27 the joint stock is necessarily pivotal. Considering the distance of the bearing 52 (or 522) from the joint stock 51 (which is the final supporter of the gear G n in all of the above cases), one may say that Figs. 25, 26 and 27 present the cases of external , medium and internal supporting of the gear G n , respectively. To note in Figs. 25-27 is also that the stationary forward part (calotte) 551 of the housing bears the whole of the joint 5G (gears G₁, G₂,..., G n and stock 51) while the aft part 552 serves only as a (pivoting) cover to it (and is also born by it). However, if the aft calotte (part) lies precisely on the forward one, then one may dispense with the curved arm(s) 53, 53L or the other means for the bearing 52 to be directly supported by the joint stock 51. Namely, in this case the bearing 52 may be fixed to the aft calotte (part) 552, cf. Fig. 28. Pins 5512 and 5512L connect the two housing parts 551 and 552 (part-connecting pins) and also align the axes of the two parts, which axes coincide with the joint stock's 51 axis V₅₁ = V (so that the bearing 52 is now indirectly - through the part 552 and pins 5512, 5512L - again connected to the joint stock 51). The latter property makes the part-connecting pins generally recommendable. Pins 5512 and 5512L may be external (fixed to the stationary part 551, Fig. 28) or internal (fixed to the pivoting part 552). Mixed cases are possible as well. In general, the joint's horizontal shaft 25i may be supported in any way enabling its pivoting around the axis V₅₁ = V₅ of the joint stock 51. One of such ways has been presented in Fig. 23 where, instead by the joint stock 51, the said shaft is supported by the horizontal ring RG carried by the housing 55 (or by its stationary part 551 if the design considered is rearranged into the third variant). Another way has been shown in Fig. 22 where the shaft 25i is supported by the bush 55BS carried by the riding band 6BR. There are other ways, too. The two housing parts 551 and 552 are generally of the same form and they fittingly ride on one another. This is necessary both for the compactness striven for here and the strength of the housing. The stationary part 551 should in any case be provided with the aft horizontal window 5510 to allow the propeller shafting 25,25i to pass through it and perform its steering turning ± α m . This window may but need not be sealed since it is covered by the pivoting part 552 so that the mandatory general sealing of the two housing parts is responsible for this window, too. On the other hand, the propeller shafting 25,25i passes "normally" (without a "window") through the pivoting part 552 of the housing since the said shafting and part 552 pivot together. This passage should not be sealed if the jacket 33J (or 33J') connects the propeller shaft bearing 34 with the turning housing part 552 and thereby closes the whole room 570 in between, cf. Figs, 33, 38, 42, 54-56, 60-62. Functionally, each housing part is integral but for production and mounting reasons the parts may be made of several subparts. There may be only one seal between the parts 551 and 552 in the MMP or two such seals 62M (standard Simmer or lip rings, O-rings, rings with grooves, etc.) may be fitted near the MMP, Fig. 29; in the latter case the inter-calotte chamber 55i (space between the two seals) is filled with oil from the header tank HT (so that the oil pressure in the chamber 55i is somewhat higher than that of the surrounding water). To note is, however, the following. In the case of the vertical MMP-seal 62M and with the axis V of pivoting being vertical, the points of such a seal move perpendicularly to the seal's plane so that there are the surfaces on the stationary part (calotte) 551 which are intermittently covered by the pivoting (turning) housing part 552 and thereafter exposed to the external water (case of rubbing velocities being perpendicular to the seal's plane). Therefore, some cleaning of these surfaces should be provided (brush ring 552R in Fig. 29) in order to reduce their fouling. (There is, however, no such phenomenon with the horizontal EP-seals where the points of the seal keep moving in the plane of the seal only - case of rubbing velocities being in the seal's plane). Besides the inter-part seals 62M, there may be fitted to the joint 5 a boot seal 555 fixed to the forward part (calotte) 551 in the range of its shrinking on the stern tube 24 and to the forward rim of the aft part (calotte) 552 so that it covers the very entry to the inter-part space 55i, Fig. 30. Therefore, it will be called the entry boot seal . (Let us note that the entry boot seal 555 has already been used with the universal joints, that is, with the 1st variant, cf. Fig. 9). Needless to say, the simple entry seals ES, Fig. 17, may also be applied here. The entry boot seal 555 may be protected by the stationary spheric protector 571 fixed to the forward calotte 551 in the range of its shrinking on the stern tube 24, cf. Fig. 30. This protector is extended aft beyond the MMP so that it covers the entry boot seal 555 even at the maximum steering angle ± α m and thus does so permanently. The gap between this protector's opening and the aft calotte 552 may also be sealed (stationary seal 571s that rubs against the turning aft calotte 552, cf. Fig. 30). The (partly or completely) pivotal joint housing 55 with the 3rd and 4th variants may be protected by a protrusion 151 of the ship's stern 11 that embraces the joint housing 55 (cf. Figs. 13,h, 33, 34 and 13,i, 39 for the 3rd and 4th variants, resp.) and lets (through the gap in between) the external water enter the space 153 of the protector (protrusion) 151 and stand there as "dead" (almost immovable) water (ballast). The protector 151 may be either permanently fixed to or dismountable from the ship's stern 11. Since in the final account it protects the joint 5, it will be called the joint protector . To note is that, by the way, the joint protector 151 may serve as a good stern bulb for a better induction of water by the propeller - which is a property to be only welcomed. Now, once the joint protector 151 having come close to the joint housing 55, the gap 150 between the joint protector's opening and the joint housing may be sealed and thereby the joint 5 may virtually be "incorporated" into the ship's hull. For a spheric (two-calotte or the like) housing 55 the said gap 150 is circular and then the standard circular-ring seals are readily applicable for the joint protector seal 152. These are reliable seals and they make it that the space 153 within the protector (stern protrusion) turns out to be dry. Some of a multitude of variations of seals 152 are presented in Fig. 31 (a ring with grooves) and Fig. 32 (three Simmer rings; by pipe and channel 154 the chamber 151i between the forward rings 152F and 152M is filled with header tank oil while the aft ring 152A is responsible for the gap 150). Designs with one seal active and with a special device for the stand-by seal ring to be engaged after the first one has yielded are also possible. With the unsealed or sealed joint protectors the interior of the joint 5 or of space 153, respectively, may eventually be held under a slight air overpressure. One of a multitude of embodiments of the forward-aft (MMP-sealed) version of the 3rd variant of the installation is presented in Fig. 33. Two parts 551 and 552 of the two-part housing 55 are calottes. The forward (inner) calotte 551 is shrunk (by its bush 55B) on the stern tube 24 and the two calottes are aligned by the internal part-connecting pins 5512 and 5512L. The aft (outer) calotte 552 is extended forward beyond the MMP (its dividing plane is in the EP - see the shading of 552). The RGJ 5G consists of four bevel gears G₁, G₂, G₃, G₄ (G₄') and there is the joint stock 51. The joint's horizontal shaft 25i is supported by the out-of-joint-stock bearing 52 (that is carried by the curved arm 53 and bearing 54, hence by the joint stock 51) and the in-joint-stock bearing 522 whereby the external and internal supports, resp., of the gear wheel G₄ are realized (cf. Figs, 25 and 27). The gear wheel G₂ has a platelike form to conform better to the spherical housing and also to make free room between the pinion G₁ and the wheel G₄' (which room is necessary for the free pivoting of the pivoting assembly of the joint). The aft calotte 552 is connected to the propeller-shaft bearing 34 by the elastic jacket 33J' enveloping the flexible (rubber) coupling 292 between the shafts 25i and 25. The inter-calotte sealing is provided for by the circular ring seals 62M. In addition, there is the entry boot seal 555 with its stationary spherical protector 571 (cf. Fig. 30) that is fixed to the stern tube 24 (to the bush 55B). Finally, there is the joint protector 151 with its circular ring seal 152 and brush ring 152R. The joint protector space 153 is provided with the bilge system 71. The steering turning to the turning assembly of the joint is transmitted from the curved lever 33 through the coupling 532, 531 to the outer calotte 552 to whose pin 5512 is keyed the joint stock 51 and then through the bearing 54 (that is also keyed to the joint stock 51) and curved arm 53 to the bearing 52 of the gear wheel G₄. Clutches MDC (of any design) mesh either the gear G₄ or gear G₄' with the joint's horizontal shaft 25i whereby the reverse reduction gear joint is achieved. Oil or air or else to control the clutches is conducted through the oblique access tube 165, collar 51c and joint stock 51. An embodiment similar to that of Fig. 33 is shown in Fig. 34. However, the flexible coupling 292 is now located in the very joint 5G (it is a metalic rather than rubber coupling). Then the aft calotte 552 has the forward subpart 552S connected to it by screw thread. Since there is no external (out-of-joint-stock) bearing 52 to the shaft 25i, the internal bearing 522 (within the bush 514 in the joint stock 51) is pretty long and the shaft 25i is splined there (spline 515) while the gear wheels G₄, G₄' revolve on the spline's bush 514. The joint stock 51 is passed upward through both calottes and then connected with the rudder stock 3 by the double slider (Oldham) coupling 513 whereby a direct steering-turning transmission to the pivoting assembly of the joint is performed. The propeller 26 is shrouded by the Kort nozzle that is fixed to the curved lever 33. In Fig. 35 there is presented a forward-aft two-calotte version of the 3rd variant where the shafts 23 and 25i are coaxial ( a = 0). Owing to the multidisk (or other) clutches MDC and gear G₁' this RGJ is reversible. Besides the MMP seals 62M there is also the entry seal ES. The steering gear 32 turns (by quadrant SC) the joint stock 51 and thereby also the propeller supporting system 33, 33L, 34 (hub 330 is keyed). Due to the tunnel 55T, quasi stern tube 24Q and housing-born pins 541, 541L (which may be merged with the part-connecting pins 5512, 5512L) this is an RSPC (or an MRSPC) within the 3rd variant (elements 34, 33, 33L and 55, 55TG belong to the assemblies 331T and 331S, resp.). A presentation of the EP-sealed versions of the 3rd variant is given in Figs. 13,d, 38 (version lower-upper) and 13,e, 36, 37 (version upper-lower). The housing parts 551 (stationary, shrunk on the stern tube 24, provided with the window 5510 for the shaft 25 or 25i) and 552 (pivotal, lying on the stationary part 551, with the shaft 25 or 25i passing through it normally) are cylindrical vessels ("pots") there but they might also be calottes, etc. Since the inter-part EP-seals are necessarily located in the horizontal planes between the driving and driven shafts, there is an appreciable axis displacement a in this case (with the lower-upper and upper-lower versions the axis displacement is positive and negative, resp.). The version upper-lower in Fig. 36 can receive a broad (vertical or oblique) access tube 165 but there is little use of it since it meets horizontal wheels G₂ and G₃ which block the entry to the joint. However, the configuration in Fig. 37 offers a broad and free access on account of the horizontal wheels G₂, G₃ being in the bottom of the housing owing to the vertical spur gears G a and G b. To note is that the top of the stationary upper part 551 in Figs. 36 and 37 is not closed, the upper bearing 5BU of the joint stock 51 being supported by the brackets 51BR. By CUL is presented the connection of the housing parts or pots (the pivoting part 552 "hangs" on the stationary part 551). Another way is that the stationary part 551 provides a foothold (between the seals 62E and shaft 25i or elsewhere) for the pivoting part 552 to hang on it by a foot. [The left missing portion in Figs. 36 and 37 (containing the elements 25, 34, 292, 33J connected to the pivoting housing part 552, etc.) is the same as in Fig. 38.] In Fig. 38 there is presented a lower-upper version of the 3rd variant where both parts of the two-part housing 55 are cylindrical pots (note should be taken that the cylindrical surfaces of pots are easier to produce and fit than the spherical ones of calottes). The EP-seals 62E (with the chamber 55i between them filled with overhead-tank oil) lie now in the horizontal planes (which are necessarily between the driving and driven shafts) and thus all the rubbing is made only in the seals' planes. The propeller-shaft bearing 34 is by the strong cone-shaped jacket 33J connected to the turning upper housing part 552 which, through bearings 55U, 55L and 55A (or directly), is supported by the stationary lower part 551 that is (by its bush 55B) shrunk on the stern tube 24. Thus, the pivoting assembly 331T and, the stationary one 331S of the carrier 331 consist of the elements 34, 33J, 552 and 55A, 55U, 55L, 551, 55B, 24, resp. (steering gear 32 fitted on the stern tube 24 turns directly the pivoting part 552; alternatively, a special steering gear may be fitted in the cylindrical chamber between the parts 551 and 552). This is a specific kind of the PSC 331 where, in a sense, the lower pot 551 as a whole stands for the stern-tube supported pin 241 while both housing parts 551 and 552, belonging to the PSC 331, are carrying elements (with, in the final account, both of them being carried by the stern tube 24 and stern 11). To note is that the propeller shaft is well protected by the jacket 33J which, being rigid, transmits the propeller thrust through the housing parts 552 and 551 to the stern tube 24. This version (lower-upper) has no stationary access (since a vertical or oblique access tube would hit the pivoting pot 552, however, a vertical pivoting access tube extending from the upward open parts 552 and 551 is still possible). With the upper-lower versions of the 3rd variant with the EP sealing (Figs. 13e, 36, 37) the maximum steering angle ± α m is the same as with the lower-upper versions if the (now negative) axis displacement a is small (the propeller 26 should not hit either the stern 11 of ship or the driving shaft 23). However, a somewhat greater value of the axis displacement a (possibly combined with a smaller diameter of the propeller 26) enables the upper-lower versions of Figs. 36, 37 and similar designs (where the steering gear should activate either the joint's stock 51 or the turning housing part 552) to yield ± α m = ±180 o which is - in this respect - the same situation as with the Z-drive (the basic difference lying in the fact that there is now no vertical torque-transmitting shaft as with the Z-drive). The fourth variant of the installation, Fig. 13,f, is "symmetrical" to the second variant, Fig. 13,b, and therefore the sealing of the forward window 550F with the fourth variant may in principle be made in completely the same way as the sealing of the aft window 550A with the 2nd variant (see Fig. 14 where for this reason there are double designations 25(23) and 550A(550F)). As a matter of course, since the arced plate(s) 6 and riding band 6BR now (with the fourth variant) ride on the driving shaft 23 which is revolving but stationary in space, they are not pivoting while the housing 55 itself is so (which is just the reverse of the second variant). The vicinity of the forward window to the stern 11 of ship offers, however, the other ways to seal the forward window 550F. The basic of them is as follows. The forward wall of the housing 55 containing the forward window 550F is either made as a horizontal circular arc or is simply formed spherically (the latter may also refer to the housing 55 as a whole). Then the stationary protrusion 171F from the stern 11 - to be called the forward-window protector -holds and presses to the housing (providing a face) the face (mechanical or other) seal 172F of any appropriate design and thus seals the forward window (cf. Fig. 39 presenting an embodiment of the 4th variant). In addition, the window 550F itself is closed by the boot seal 174F that is fixed to the forward wall of the housing 55 (within the window protector) and to the boot seal collar 175F that rides on the driving shaft 23 (and that is analogous to the collar 660 in Fig. 18). (Instead of to the collar 175F, the forward end of the boot seal 174F may also be fixed either to the inside of the forward window protector 171F or to the very stern 11 of ship within the protector.) The bearing 521 of the pinion G₁ is carried by the curved arms 561 and 561L which are freely supported by the joint stock 51 by means of the bearings 541 and 541L, respectively (external support of the gear G₁). The gear wheel G n = G₄ is supported by the bearing 522 within the joint stock (internal support of the gear G n ). The driving shaft 23 (which is supported by the bearing 521, hence by the joint stock 51) and the intermediate driving shaft 23F (which is supported by the stern tube 24) are connected by the flexible coupling 292F where misalignment and other assembly errors are compensated for. The rods 176 connect (by springs 176S) the collar 175F to the stationary window protector 171F whereby the assembly of elements 521, 561, 561L is kept in the central plane (CP) without the aid of the flexible coupling 292F to that effect (connections 176, 176S are by far stiffer than the compliance of the flexible coupling and thus they transmit the reaction to the matching force of the gear G₁ with gear G₂ to the window protector). In addition, the said connections prevent the collar 175F to revolve (due to the friction torque imparted to it by the shaft 23). In the forward housing space there may be fitted the boot seals closing the forward window 550F from inside (in the same way as such seals have been applied to close the aft window 550A with the 2nd variant - see the internal boot seals 68 in Fig. 18). In the window protector space 173F and joint protector space 153 there are bilges 7 with bilge systems 71. So far, the window protector 171F and the face to its seal 172F on the housing have been stationary and turning, respectively. The reverse case is obtained if the window protector is fixed to the housing 55 and thus gets to be turning with it while the face to its seal is provided by the stationary stern which yields a sealing surface for that purpose that should be concave to the protector. The access to the RGJ 5G in the case of the 4th variant may be provided by and through a vertical pivotal tube 165 which is fitted instead of the massive stock 3. Generally, the sealing of the forward window by the window protector 171F - which thus yields the 4th variant with protector sealing of the forward window - seems to be very efficient. This being the case, the protector window sealing may be applied also to the aft window 550A with the 2nd variant. In this case, instead of the forward window 550F and its protector 171F there are the aft window 550A and its protector 171A, respectively, and the support to the protector 171A of the window 550A should be provided by the pivoting propeller shaft bearing 34 (or some other part of the pivoting assembly 331T) with the housing 55 being stationary while all the rest should, in an analogous way, be as with the 4th variant with protector sealing of the window. Hence, just as already mentioned protector 171A (corresponding to the protector 171F), there should also be the elements 172A, 174A, 175A, etc. (corresponding to the elements 172F, 174F, 175F, etc., respectively). To note is that by some transformations a lot of designs belonging to the 2nd, 3rd and 4th variants containing the RGJ 5G ("housing variants") can change their variant classification. This holds generally but is particularly feasible in the case of transforming from the 2nd to the 3rd variant. In doing so, on reducing the former one-part housing to the stationary housing part 551 and introducing the pivoting housing part 552 - the arced plate 6 with its guides 56 is cancelled and substituted by either the 62M or 62E seals located near the MMP or in (parallel to) the EP (between the shafts 23 and 25,25i) with the forward-aft or lower-upper (or upper-lower) versions, respectively. Thereby, a lot of combinations yielding a multitude of versions are possible, too. One of a multitude of such transformations and combinations is shown in Fig. 40 that derives from Fig. 23 (horizontal ring RG, etc.) but is also combined with Fig. 38 (two cylindrical pots, etc.) so that a lower-upper version of the 3rd variant is obtained. However, in Fig. 40 there is also the vertical tube 55t (within the structural tube 55S) the lower portion of which is splined with both the hub 330 and pivoting housing part 552 while its upper end is turned by the steering gear 32 and worm wheel 32W. This pivoting tube substitutes for the (stationary) access tube 165 and thus it is through it that the necessary piping and cabling are led to the multidisk or other clutches MDC, etc. The tube 55t is lowered down (and thereby splined, keyed, etc. with the hub 330 and housing part 552) only after the bush 55B has been shrunk on the stern tube 24 ("lowering tube connection"). (The curved levers 33, 33L may be substituted by the cone-shaped jacket 33J fixed directly to the housing part 552 in which case the hubs 330, 330L are omitted.) Hence, this is an RSPC even though the steering gear 32 is outside the compact ("S" in RSPC refers to the property of steering as such rather than to the very steering gear 32). In some cases the transformation brings forth "hermafrodite" solutions. One of a multitude of such solutions is presented in Fig. 41 that derives from Fig. 22 (2nd variant with the riding band 6BR) where the inner tube 55V (housing) has been extended upward to pass through the structural tube 35. The upper rim of the riding band (outer tube) 6BR has also been raised above the water level WL and therefore the upper seal 62EU has been omitted. Now, with only the lower seal 62E (and possibly an entry seal ES) existing, and by hanging by its foot FT on the foothold 6FH of the inner tube 55V, the riding band 6BR may also be considered as the pivoting part 552 of the two-part housing 55 riding on the stationary part 551 (tube 55V) - which turns out to be the 3rd variant (version lower-upper, but with the part 551 extending upward beyond part 552). The mounting is performed by a vertical insertion of the tube 55V into tube 35 which is followed by an axial aftward shifting of the stern tube 24 (in its guide 24G) to fit it into the tube 55V or its possible bush 55B (elements 55V, 35, 24 make the assembly 331S). The turning of the riding band 6BR or housing part 552 (and thereby of the propeller-supporting system 33-33L (or 33J), 34 which is fixed to the band 6BR and which all make the assembly 331T) is performed by the steering gear 32 and quadrant SC fixed to the band 6BR; the stationary part 55V or 551 is provided with the aft window 5510 to pass through it the shaft 25i and curved arm 53; extension 582 of the band 6BR (part 552) rides the curved arm 53 whereby the pivoting of the joint assembly is performed. Fig. 42 is the previous design for the case of a vertical stern (transom) 11. The stern tube 24 is immovable (structural) in this case so that the inner tube or stationary housing part 551 (specifically, its bush 55B) is in its horizontal shifting shrunk onto it whereupon the radial horizontal bearing 36H is fastened. The outer tube (pivoting housing part 552 or riding band 6BR) hangs by its foot 6F on the upper foothold 6FH offered by the inner tube (part 551 or housing tube 55V). [Alternatively, the foothold 6FH and foot 6F may be put near the lower edge of the tube 552 - so that the latter tube is supported by the tube 551 rather than hung on it - in which case, as in Fig. 17,a, also its very seating 6SL gets to support the sealing action of the seal 62S.] The seal 62E is at the lower end of the outer tube 552 (riding band 6BR) and it prevents the access of water in between the said tubes [if the outer tube 552 is short, there may exist also the upper seals 62EU just above the propeller shafting.] The steering gear 32 is fixed either to the stern 11 or to the bearing 36H or to the inner tube (part 551) in which case it is meshed with the outer tube 552 through the window 550U (alternatives 32, (32), [32], respectively). The propeller-shaft bearing 34 is supported by a closed cone-shaped jacket 33J fixed to the pivoting tube 552 whereby a stern bulb is formed before the propeller. Ladder LD within the inner tube 511 serves to descend to the RGJ 5G. Summarizing, the design in Fig. 42 (hermafrodite of the 2nd and 3rd variants where the elements 551 (55V), 55B and 552 (6BR), 33J, 34 belong to the assemblies 331S and 331T, respectively) appears to be a very simple and straightforward RSPC. It will be called the "vertical-tube" version of the installation. Fig. 61 is the same solution in the case of the strut STR where the bush 54 is shrunk onto the strut bearing 244. Another hermafrodite design is presented in Fig. 43. The heel of the stern 11 is formed as a stool ST holding the stationary part (short vertical tube) 551 into which is entered the stern tube 24 and shaft 23 with pinion G₁. Then the pivoting part (long vertical tube) 552 holding the joint stock 51 with its gear assembly G₂-G n and also the propeller supporting system 33-33L (or 33J), 34, etc. is inserted vertically till its end (bottom) lies on the bottom of the tube 551 (and thereby the gear G₂ meshes with gear G₁ and also seals 62E get tight). The clamp, buckle or similar radial horizontal bearings 36H are then fastened around the tube 552. Now, following the action of the steering gear 32 through the quadrant SC the tube 552 is turned together with the propeller supporting system and the joint stock assembly within it (elements 34, 33, 33L, 552 and 551, 36H belong to the assemblies 331T and 331S, resp.). Hence, by its two-part housing (parts 551 and 552) this is the 3rd variant. However, since the tube 552 is necessarily provided with the forward window 5520 to ride (in its steering pivoting) over the stationary stern tube 24 this may be considered also as the 4th variant (where the one-part housing is necessarily provided with the forward window 550F). For, the stationary stool ST and short tube 551 may be considered as some "extensions" of the stern 11 and then what remains is the pivoting "one-part" housing 552 (however, the forward window 5520 is not sealed directly since "its" sealing is relinquished to the inter-part seals 62E). The design may also be viewed as that of Fig. 12 where the housing and stock 3 have been merged and transformed into the vertical tube 552 calling for the horizontal seal 62E. If the access is dispensed with, then the tube 552 may be shortened and closed with some cover (just above the lower bearing 36H) and then continued (through a double slider or similar coupling) into the vertical stock 3 with the steering gear 32 still on (or near) the deck (if the tube 552 is ended somewhat above the water level, then an emergency access to its interior (joint 5G) is still possible upon removing the stock 3 and the tube cover). Or, after the tube shortening, the steering gear 32 may be put on (or near) the bottom of the tube 552 and then, through a window, meshed with the stationary tube 551. Or, it may be fitted to the sternpost below the bearing 36H or on the stern tube 24 and meshed with the tube 552 from outside. In some cases it is difficult to tell the 2nd and 3rd variants from one another. This is in particular the case when the riding band 6BR is applied with the 2nd variant that may be also conceived as the pivoting part (tube) 552 with the 3rd variant (for this reason, the elements 55V, 6BR, 550A in Figs. 22 and 42 are designated also as 551, 552, 5510, respectively). The difference is in the fact that the shorter riding band is provided with both lower and upper seats (guides) and seals whilst the longer pivoting part (tube) 552 has just one (either uppper or lower) seating (foot 6F on foothold 6FH) and only the lower seals. Now, let us present the hydraulic joints the application of which presents the fifth variant of the installation, Fig. 13,g. In principle, it is a hydraulic transmission of torque that is performed within a hydraulic joint where for this purpose the incoming driving shaft 23 and outgoing propeller (or driven) shaft 25 are provided with specific "coupling elements". Four of a multitude of hydraulic joints will be presented here. The first one is as follows (Fig. 44): The driving shaft 23 bears a set of longitudinal (radial) plates with semicircular external contours to be called the inner blades IB. The driven (propeller) shaft 25 bears a hollow sphere SH with inner longitudinal (radial) plates (ribs), to be called the peripheral blades PB, the internal contours of which are also semicircular. The sphere SH with peripheral blades PB and the imaginary sphere enveloping the inner blades IB are concentric with point C being their common center. The gap between the mentioned contours of the inner and pripheral blades is small. The sphere SH and peripheral blades PB have an "opening" OP (they do not exist) in the forward solid angle with the cone angle slightly greater than ϑ OP = α m + ϑ where ϑ = angle to allow for the radius of the (driving) shaft [cone angle is the angle which an element of cone makes with the cone's axis which, in this case, coincides with the axis of the driven shaft 25 while the cone's apex is in the center C; the said solid angle ϑ OP has 2π(1-ϑ OP ) steradians or 2(1-cosϑ OP )·180 spherical degrees.] The blades IB and PB (which may possibly be connected with transverse vanes TVI and TVP) are the coupling elements of the driving and driven (propeller) shaft, respectively. As a rule, the numbers of blades IB and PB are unequal. The system is encompassed by a two-calotte housing 55 (basically as with the third variant of the installation but with the housing parts now necessarily being calottes), the forward calotte 551 being by fixation related to the sterntube 24 and thus stationary while the (non-revolving) aft one 552 is pivotal (together with the propeller shaft 25 in its bearing 34, then with the jacket 33J connecting the aft calotte 552 to that bearing and with the sphere SH) around the part-connecting pins 5512, 5512L, i.e. around the vertical pivoting axis V₅ = V passing through the center C (which is due to the fact that all of the listed elements are held by the pivoting assembly 331T of the PSC 331; to note is that the aft calotte 552 and sphere SH are fixed to the bearing 34 of the propeller shaft 25 and the propeller shaft 25 itself so that they are pivoting and both pivoting and revolving, respectively). The stationary calotte 551 has the aft horizontal window 5510 to allow for the steering turning (pivoting) of the propeller shaft 25 while the two calottes are sealed in the usual way (vertical seals 62M with posssible entry seal ES, boot seal, etc.). As usual, the aft window 5510 of the stationary calotte 551 is not sealed since it is covered by the pivoting aft calotte 552 which is connected by the closed jacket 33J with the bearing 34 of the propeller shaft 25 so that the propeller-shaft space is waterproof. The housing 55 is either partially or completely filled with some heavy fluid or fluidized and graphitized powder or powder with balls, etc. - to be generally called the (heavy) "fluid". In the case α = 0 the shafts 23 and 25 are coaxial. Then, the rotation of the driving shaft 23 with the angular velocity Ω₂₃ is imparted to the fluid which, due to the ensuing centrifugal force, is thrown to the periphery, that is, to the sphere SH. Therefore, a rotating either ring RI or ball of fluid for the housing being filled with fluid partially or completely, respectively, is built up in the plane perpendicular to the common axis of rotation of shafts. The thickness of the fluid ring RI is such that the fluid, while being strongly pressed by the centrifugal force to the sphere SH, is present within both the inner and peripheral blades and therefore the torque of the driving shaft 23 is transmitted (through the inner blades IB, fluid, peripheral blades PB and sphere SH) to the driven (propeller) shaft 25. Since some slipping is inherent to the fluid transmission (in the case in hand, it occurs mostly in the fluid in the gap between IB and PB), the angular velocity of the driven shaft Ω₂₅ is slightly less than Ω₂₃, Ω₂₅( α =0) < Ω₂₃ , but the transmission (torque, velocity, efficiency) should in general be good. Now, with the propeller shaft 25 being deflected in the horizontal plane by the steering angle α m , Fig. 44,c, the process of transmission will basically be the same. However, since the fluid cannot simultaneously rotate in two different planes (planes perpendicular to the two shafts with the angle α m between them) it will generally rotate in a "compromise" or medium plane m which is at the angle α m /2 to the said planes. In this case the particles of fluid will have a first order (one period per one revolution) back and forth (axial) motion along the blades and also a first order "deformation of fluid chamber forms" within the blades and vanes will ensue due to the change of angles between the inner and peripheral blades and vanes (the angles are zero and in a maximum for the blades being in horizontal and vertical positions, respectively, a period of change of angles reading 0, α m /2, 0, - α m /2, 0) - whilst neither of these effects was existing in the case α = 0. This means an additional loss of energy followed by an increase of slip, Ω₂₅( α = α m) < < Ω₂₅( α =0) , and decrease of efficiency but the transmission in general should still be acceptable. [The additional loss of energy may be reduced by making the blades IB and PB pivotal around their radial pins on shaft 23 and sphere SH, respectively. The deformation of fluid and its friction are then substituted by the friction in the blade-pin bearings in the first order pivoting of blades around their pins.] Hence, it is due to the slip that the driven shaft velocity is always less than the driving shaft one (the greater α the greater the velocity difference) but for a uniform Ω₂₃ the velocity Ω₂₅ is also uniform (for α being constant). Since based mainly on the action of the centrifugal force, this joint will be called the hydraulic centrifugal joint . This joint has two versions; version with fixed blades and version with pivoting blades (around their pins). The blades are in general plane in which case the joint works equally well in both directions of rotation. If they are curved, then one may achieve a better efficiency in the ahead running than in the astern one. The second hydraulic joint is as follows (Fig. 45): The driving shaft 23 bears a set of concentric spheres B23 (coupling elements) slightly separated from each other. The spheres have an opening OP (they do not exist) in the aft solid angle with the cone angle ϑ OP . Similarly, the driven (propeller) shaft 25 also bears a set of concentric spheres B25 (coupling elements) which, however, have the opening OP in the forward solid angle with the cone angle ϑ OP . Point C is the common center of the two sets of spheres B23 and B25. The driving and driven shafts end and begin somewhat before and behind the point C, respectively, so that they are in no contact. The diameters of the two sets of spheres are such that in the space between two successive spheres of one set there is one sphere of the other set (in other words, the spheres are "intermingled"). The spheres of the two sets are in no (mechanical) contact but the gaps between them are small. The system of the two sets of concentric spheres is enveloped by the two-calotte housing 55 (stationary calotte 551 and pivoting calotte 552) as with the previous hydraulic joint. The housing is filled with some viscous fluid. Now, for α = 0 the shafts 23 and 25 are coaxial and the spheres B23 of the driving shaft 23 (driving spheres) rotate with that shaft (angular velocity Ω₂₃). But, since the gaps between two sets of spheres are small with the coverage angle of (slightly coarse) spheres amounting to π - 2ϑ OP , cf. Fig. 46,a, the friction of the viscous fluid will make it that the spheres of the driven shaft 25 (driven spheres) and thus also the shaft 25 will rotate as well (angular velocity Ω₂₅( α =0)). Due to the friction losses, heating, etc. there will be some slip between the two sets of blades yielding Ω₂₅( α =0) < Ω₂₃ but the transmission will generally be good. The particles of the fluid will rotate in planes perpendicular to the common axis of the shafts 23 and 25. For α = α m there will be the "inner" and "outer" ranges (in the horizontal plane) where the angle between the shafts is decreased and increased resulting in the coverage angle of spheres being increased and decreased and amounting to π - 2ϑ OP + α m and π - 2ϑ OP - α m , respectively, cf. Fig.46,b (plan view). The torque and speed will be transmitted in this case, too, but the fluid particles will rotate in planes which are generally parallel to the "medium" plane m (plane at the angle (π - α m )/2 to the axes of the shafts in the inner range). This and the different sphere coverages in the two ranges will result in the fluid particles also having a first order axial motion along the blades which, all together, will yield a greater slip than before, Ω₂₅( α = α m ) < < Ω₂₅( α =0) < Ω₂₃ , but the transmission in general (torque, velocity, efficiency) will still be acceptable. For α = const a uniform rotation of the driving shaft will yield a uniform rotation of the driven shaft, too. This joint is based on the friction of fluid between the closely adjoining (concentric) spheres and therefore it will be called the hydraulic multisphere friction joint . The heat generated by this friction joint can easily be transferred to the surrounding water. The third hydraulic device will first be presented in its cylindrical version (coupling) and then in the spherical one (joint). There is the inner cylinder C23 with axial external grooves G23 and coaxial outer (hollow) cylinder C25 with axial internal grooves G25 (both cylinders may also have transverse vanes across the grooves), which cylinders are connected to the shafts 23 and 25, respectively, Fig. 47. The set of cylinders is enveloped by the sealed stationary cylindrical housing filled with fluid or, simply, the outer cylinder may be sealed and filled with fluid serving thus as a (revolving) housing. Now, the rotation of the inner or driving cylinder C23 makes it that the fluid in its grooves G23 gets both peripheral velocity (due to rotation) and radial outward velocity (due to the centrifugal force) whereby it is thrown into the grooves G25 of the outer cylinder C25 which is thereby rotated in the same direction as the inner cylinder. The process is continuous whereby the "new" masses of fluid keep being whirled into the outer grooves G25 while the "old" masses found there (which have alreaady delivered their energy to the outer cylinder) keep being expelled therefrom and returned to some successive inner grooves G23, etc. Thus, during one revolution of the cylinder C23 an observed mass of fluid gets to be several times whirled to and returned from the external grooves G25 which means that rather high torques can be transmitted by this coupling. This coupling can be generally applied in mechanical engineering. To make a joint out of this coupling, all that should be done is to transform the cylinders C23 and C25 (coupling elements) into the inner sphere S23 with external "meridional" grooves SG23 and outer (hollow) sphere S25 with internal meridional grooves SG25, resp. (two "poles" of meridians of a sphere lie in the axis of its shaft), with the outer sphere being pivotal around the vertical axis V = V₅ through the common center C of spheres for which reason it is provided with an opening OP in the forward solid angle, Fig. 48 [if the driven shaft 25 stops before or enters within the inner sphere S23 (till at most near the center C), then the inner sphere S23 shall not or shall also be provided with an opening OP in its aft spherical angle ϑ OP , respectively]. The housing is made of two calottes 551 and 552 as with the previous hydraulic joints. Owing to the above modifications, the coupling has become a joint that can be used both for α = 0 and α > 0. For α = 0 the meridional internal and external grooves SG23 and SG25, resp., are "parallel" and the situation is basically the same as with the cylinder hydraulic whirl coupling. For α > 0 the said grooves are, however, at the angles α and - α in the zenith and antizenith positions, resp., and zero in horizontal positions so that a given groove SG23 (fluid deriving from it) imparts a changing amount of torque to the sphere S25 during one shaft revolution but since there is a number of active grooves SG23 at different positions the total amount of torque received by the sphere S25 is constant (for α = const) and thus for a uniform Ω₂₃ there is also a unifrom Ω₂₅ (with Ω₂₅ < Ω₂₃ due to the slip). Since based on the whirling action, this joint will be called the hydraulic sphere whirl joint . Let us now turn back to the hydraulic multisphere friction joint. To increase the torque transmitted by that joint, one may artificially intensify the roughness of its spheres by providing them with ribs transverse to the fluid flow. This actually yields the (meridional) "grooves" on the surfaces of spheres and thereby the fourth hydraulic joint is obtained which is a combination of the second (friction) and third (whirl) ones. Namely, by letting the centrifugal force to whirl the fluid from the driving to the driven spheres only, it is but the external surfaces of the driving spheres and internal surfaces of the driven ones that are to be ribbed or grooved (whirling) while the internal surfaces of the driving spheres and external surfaces of the driven ones are to remain ribless or grooveless (friction). Since the whirling is preponderant, this joint will be called the hydraulic multisphere whirl joint . [As soon as there are more than one sphere on each of the two shafts, the propeller shaft 25 necessarily enters within the driving spheres so that both sets of spheres are to have their openings OP (the driving and driven spheres are to have their aft and forweard openings, resp.).] To note is that several different hydraulic joints are invariably put in a same two-calotte housing 55. For this reason we keep speaking about the "fifth variant", which variant - on account of different hydraulic joints in the same housing - might be construed as consisting of several "subvariants". Since with the hydraulic joints 5H described the driving and driven shafts are in no direct (mechanical) contact (the contact is only hydraulic) - these joints are selfadjustable to some slight misalignments of the "systems" of the driving and driven shafts. For the same reason they also easily endure all kinds of vibration (axial, transverse, torsional) and even act as a damper to them (or divide the system in two subsystems). Therefore, generally no flexible coupling 292 is necessary between these joints and the propeller-shaft bearing 34. Besides, due to their slip the hydraulic joints 5H act also as some relief elements in the case of overload. However, the above good properties of the hydraulic joints 5H are considerably reduced by a (probable) relatively poor efficiency of theirs (due to the slip, etc.) which is in particular emphasized for α = α m . Still, if the efficiency is more or less acceptable for α = 0, then it may be acceptable generally since the running at α = α m gets to be occasional only. To note is here that, on the contrary, the efficiency of the gear joints 5G is not only high but is also invariable with α (while the efficiency of the universal joint 5U is also slightly less at α m than at α = 0). By proceeding the comparison, let us note that it is only the gear joint 5G that allows the driven-shaft (output) velocity Ω₂₅ to be greatly different from the driving-shaft (input) velocity Ω₂₃, Ω₂₅ Ω₂₃, which is established simply by the transmission ratio r g . With the universal joint 5U the average output velocity is the same as the input one (r u ≡ 1). With the hydraulic joint 5H the output velocity is slightly lower than the input one (slip). However, for a uniform input velocity and for α = const ≧ 0 the output velocity is uniform, nonuniform and uniform for the gear, universal and hydraulic joints, respectively. Besides, it is only the gear joint 5G that enables the reversibility within the joint itself. The shafts 23 and 25 are necessarily coaxial with the universal and hydraulic joints. The gear joint may, however, have the shafts either coaxial or displaced (in any direction). General notes: (a) When sailing in very shallow waters it is convenient to raise somewhat the propeller in order to prevent its hitting the ground. Considering Figs. 1 and 2, this can be achieved by inclining forward the stock 3 (around the joint 5) by some angle and thereby by inclining forward also the curved lever 33, propeller-shaft bearing 34 and propeller 26 by the same angle (and thereby by raising the latter). This can be done with the universal joints 5U (1st variant) and hydraulic joints 5H (5th variant) if made universal. [Once provided with the openings OP, the hydraulic joints offer any axis of angularity in the plane containing the center C and being perpendicular to the axis of the driving shaft 23. Hence, they are inherently universal joints and it is only our hitherto existing PSC 331 with its only one (vertical) axis of pivoting V₃₃₁ = V that restricts them to act as simple joints only. Thus, "if made universal" refers basically to the PSC 331 rather than to the hydraulic joints themselves (with the exception of the hydraulic centrifugal joint where for this purpose the aft window 5510 of the stationary calotte 551 should be made as a circular opening rather than as a horizontal slot).] (b) Considering the RGJ 5G, the axes V₂₃ of the driving shaft 23 and V₂₅ of the propeller shaft 25 are parallel (or coaxial) and generally horizontal while the axis V₅₁ (= V₅ = V₃₃₁) of the joint stock 51 is perpendicular to them, β₅₁₋₂₃ = 90 o . This, however, is by no means necessary since the said angles affect only the cone angles of the bevel gears G₁,...,G n so that no particular difficulties should be met in producing the RGJs with the shaft line inflected in them. This may be applied to the V-drive, Fig. 49 (h = horizontal), where, among other things, the RGJ in hand makes it that the propeller shaft 25 is now horizontal so that the full propeller's thrust force F p is used for propulsion (rather than its horizontal projection only - which is the case of the usual lay-out where the propeller shaft 25 is a straight extension of the inclined driving shaft 23). (c) The basic transmission line (train of elements between the driving shaft 23 and joint's horizontal shaft 25i) of the RGJ includes, among other elements, the bevel gears G₁, G₂,..., Gn (n min = 3, n max = unlimited; in steering, the meshing point G n-1 ,G n of the last bevel gear G n "walks" on the circumference of the pitch diameter of the last but one bevel gear G n-1 ). If necessary, however, this basic transmission line may be extended beyond the joint's horizontal shaft 25i by a secondary set of (spur, bevel, planetary, etc.) gears G₁'', G₂'',..., G n '' or other transmission elements on condition that the propeller shaft 25 and joint's horizontal shaft 25i are strictly parallel (or coaxial) and that the said last bevel gear G n remains the only "walking gear" in the steering pivoting. An example is given in Fig. 50. (d) As a rule, the thrust force is taken by the thrust collar 342 and transmitted through the PSC 331 to the ship's stern 11. Still, a small ("parasitic") amount of thrust gets to be imparted through the propeller shaft 25 to the joint 5. The RGJs 5G (and also some of the universal joints 5U) are, however, very susceptible to axial loads. Therefore, between the propeller-shaft bearing 34 and the joint 5G there is fitted either a flexible coupling or a spline or a ball-and-trunion universal joint (working with practically a zero angularity), etc. which makes it that the joint 5 does not suffer from that thrust force. Misalignment and vibration are alleviated thereby, too. Similar elements may be built in the very RGJ 5G. For example, the spline 515 within the bearing 522 (held by the bush 514 in the joint stock 51) in Fig. 34 not only reduces the parasitic thrust imparted to the joint but also makes it that the said thrust is passed around the meshing point of the wheels G n = G₄ and G n-1 = G₃ . (e) Two protectors (shields) have been met so far: joint protector 151 and window protector 171. For the good of a general protection, however, the whole system of the joint housing 55 together with the PSC 331 may be protected as well. There is a number of ways to build these "system protectors". One of them is to conceive the system protector 191 as a "housing" to the PSC 331. Thus, in Fig. 51 there is the forward stationary outer part (calotte) 191F of the system protector which is fixed to the tunnel 55T in the guide 55TG (the design is otherwise an RSPC similar to that in Fig. 35) while the aft pivoting inner one (calotte) 191A is so to the propeller-shaft bearing 34 and curved levers. The two calottes 191F, 191A are sealed (seals 62M', ES'). The joint 5 may possibly have the same kind of housing (parts 551, 552) of smaller dimensions (not shown in Fig. 51). The joint in Fig. 51 may be of any kind (universal, gear, hydraulic). For a further illustration, in Fig. 12 there is a simple one-part system protector 191 (dashed lines) which is a stationary streamlined protrusion (hood) from the stern 11 of ship that is provided with the window 191W to allow the propeller-shaft bearing 34 to perform its steering pivoting. A similar stationary protector 191 is seen in Fig. 35. Then, in Fig. 52 there is the aft turnable protector 191A fixed to the jacket 33J. Similar protectors may be applied to the other designs as well. In general, the system protectors may - besides protection - provide also good streamlining properties to the whole of the joint. Let us now resume the discussion of the hermafrodite designs. The designs in Figs. 19 and 20 are the 2nd variant RSPCs with horizontal access 160 (tunnel 55T). In this case the inter-guide access (IGA) from forward to the joint 5G is necessary ( α IGA > 0, see Fig. 15) and therefore the circular plate 6 with the guides 56 has been applied there since a horizontal access is not feasible with the riding band 6BR. Therefore, to apply the riding band 6BR in this case, too, there is the design in Fig. 52 which holds for larger ships and where the cone-shaped thick jacket 33J (substituting for the curved levers 33, 33L) is fixed to the outer band (tube) 6BR riding on the stationary inner tube 55V (or inner housing) that is fixed to the enlarged outer housing 55D which is extended into the horizontal tunnel 55T (access 160D) carried by the structural tunnel guide 55TG. Besides, there is the lower stern extension or stool ST to support the outer housing 55D. The upper portion of 55D provides enough room for the access 160 (from above) to the inner housing (vertical tube) 55V (namely, the general access 160D to 55D (through the tunnel 55T) is horizontal while the access 160 to 55V is vertical). Besides, the outer housing 55D yields (together with the stool ST) a streamlining form which is continued into the jacket-33J supported system protector (shield) 191A down to the propeller 26. The steering gear 32 turns the joint stock 51 by the quadrant SC and then, by the arm ASC passing through the window W55 in the tube 55V, the riding band 6BR itself; the tube 55V has also the usual window 550A for the arm 53 (elements 33J, 6BR and 55V, 55D, 55T belong to the assemblies 331T and 331S, respectively). The riding band 6BR with its seals 62EU and 62EL (which are responsible for the windows W55 and 550A) is not just a sealing element here since the propeller-supporting jacket 33J is fixed to it whereby it is involved in the pivoting assembly 331T and therefore is built as a strong unit supported by the foothold 6FH of the stationary tube 55V. Therefore, this band may also be considered as the pivoting part 552 of the housing while the tube 55V itself is its stationary part whereby a transformation into the 3rd variant is obtained (elements 6BR, 55V, 550A correspond to the elements 552, 551, 5510, resp.). The tunnel guide 55TG may be provided with the cover 55TC for the substitution of the RSPC while the ship is afloat (see Fig. 58,a and related text). Designs with vertical tubes in Figs. 40-43 are the RSPCs with vertical access 160 (ladder LD). While Figs. 40, 41 are the "through-hull" cases, Figs. 42, 43, 52 are the "outside-hull" ones. The through-hull case as in Fig. 41 can be made also with a stationary stern tube 24 if the structural tubes 35 and 35L are wide enough (or if they are elliptic with the greater axis being longitudinal) to allow horizontal shifting of the tube 551 in them for its bush 55B to be shrunk on the stern tube 24 after which a radial (and radially adjustable) bearing to the tube 551 is fitted in the tube 35. Another way is to have "normal" tubes 35 and 35L and two-part tubes 551 and 552 with their upper parts being inserted (from above) through the tube 35 and connected to the lower parts (which are generally outside the tube 35) only after the bush 55B of 551 has been shrunk on the stationary stern tube. The above ways are applicable also when the outside-hull cases (such as that in Fig. 42) are transformed into the inside-hull ones. The other possibilities with the outside-hull cases are discussed in connection with Fig. 61. To note is that the RGJ 5G as a whole can be easily substituted with the vertical-access compacts. For this, the joint stock 51 should not be fixed to the ambient tube (tubes 551 or 552 in Figs. 42 or 43, resp.) directly. Rather than that, it should be (together with the gear complex G₂, G₃,..., G n ) put in a "cage" CG, Fig. 53, that is slid downward in the vertical guides GCG in the ambient tube (by overriding the ladder LD); when on the bottom of the tube and fixed, its input gear wheel G₂ meshes with the (waiting) input gear G₁; then the joint's horizontal shaft 25i and the (waiting) output (propeller) shaft 25 are connected by a (preferably flexible) coupling C25 or spline or so; if the gear G₁ is contained in the cage complex, then a similar coupling or spline or so should be between it and the (waiting) input shaft 23. The guides GCG and the seating of the cage should be precise. An additional hermafrodite design of the gearbox joint is presented in Figs. 54 (sketch) and 55, 56 (embodiments) where the stationary part 551 of the joint housing is a short vertical tube closed with the (integral) upper and lower covers (a sphere or similar element may be applied, too); for the propeller shafting 25i,25 to pivot by ± α m , this housing part is provided with the usual aft window 5510; at its forward side it is provided with the bush 55B whereby it is shrunk on the stern tube 24. The external pivoting (turning) housing part 552 is generally of the same shape but is somewhat larger and is provided with the forward window 552W so that it embraces completely the stationary part 551 except for the said window 552W whereby it rides (in its pivoting by ± α m ) over the bush 55B (or its substitute such as the connecting element 55E, Figs. 59, 60). The housing parts 551 and 552 are aligned by the joint stock 51 (or part-connecting pins). The window 552W is covered by the arced plate 6F that is fixed to the bush 55B and therefore is stationary. The guides 56F of the arced plate 6F are fixed to the pivoting part 552. The angular widths of the window 552W, arced plate 6F and guides 56F are ± α W = ± (α m +β₁) , ± α 6F = ±(2 α m + β₁') and ± α 56F = ±(3 α m +β₁') , resp., so that the arced plate 6F covers the window 552W in all of its positions. There are the seals S1, S2, S3 and S4 circumventing the windows 552W and 5510, resp., and thus having both horizontal and vertical stretches (the angular distance of the inner rims of vertical stretches is ±( α m +β₁). The seals S3 (between the housing parts 551 and 552) and S2 (between the pivoting housing part 552 and arced plate 6F) are fixed to the pivoting part 552, the seal S1 (between the plate 6F and guides 56F) is so to the guides 56F. Hence, all of these seals turn with the pivoting part 552 and thus also with the window 552W (seals S3 and S2, S1 rub against the part 551 and plate 6F, respectively.) The seal S4 (between the housing parts 552 and 551) is fixed to the stationary part 551 and rubs against the pivoting part 552. For the external water to penetrate into the joint 5G it should pass through the elements S1, S2, 552W, S3, S4, 5510 so that the joint housing is practically waterproof. The chambers between the seals S3-S4, S2-S3 and S1-S2 may be filled with oils from respectively three header tanks with pressures p 3,4 > p 2,3 > p 1,2 > p s.w. = pressure of surrounding water. A simpler case is with the plate 56F and seals S1 and S2 omitted and only chamber S3-S4 filled with header tank oil. The other both simplified and more elaborated designs are possible as well. It is seen that this is the 3rd variant of the installation (since there are two parts of the housing) but with the forward window 552W of the pivoting part 552 and the window-circumventing (rather than standard circular) seals which both reminds of the 4th variant. To note is, however, that the pivoting part 552 embraces completely the stationary part 551 (so that, instead of about two "parts", one might speak about two complete housings) and it is exactly for that reason that the arced plate 6F covers (within the window 552W) the solid wall of the stationary housing part 551 rather than hollow entrance to the joint - which presents the main difference (and a very significant one) between this hermafrodite "3rd & 4th" variant (to be called the "capsular embodiment") and the pure 4th variant. The relationship to the 4th variant makes it that the pivoting-part window 552W may also be protected by the forward-window protector 171F with face seal 172F and boot seal 174F (cf. Fig. 39); the protector 171F may be fixed either to the stern 11 (or strut STR) or to the bush 55B. In addition, there may be applied also the joint protector 151. Fig. 56 is the case of the capsular embodiment with the protector 171F fixed to the bush 55B (which is shrunk on the tube 24 extending from the strut bearing 244). With the capsular embodiment, the shafts 23 and 25i,25 may be either coaxial ( a = 0) or non-coaxial (either a > 0 or a < 0 ) since there is no horizontal seal 62E to be located between the driving shaft 23 and driven propeller shafting 25i,25 (requiring a > 0 - as with the lower-upper versions of the 3rd variant, cf. Fig. 38). Let us now discuss the reversibility of the installation. In general, it can be provided either by the engine 2 being reversible; or by fitting a reversible gearbox after the engine (in the engine room); or by applying the CP propeller (Fig. 22); or by making α m large (± α m = ±120 o with the lower-upper versions and ± α m = ±180 o with some of the upper-lower versions of the 3rd variant (negative a large); or by making the RGJ 5G reversible. In the first four cases the gearbox joint is not reversible and therefore is simple. In the latter case it is more complex (additional gears, clutches, actuators, etc.). A number of reversible RGJs have already been presented (Figs. 22, 23, 33-35, 40-43, 53). Some additional of such RGJs are shown in Figs. 55-57. In Fig. 55, the gears G₁ and G₁' are supported by the arm A1 carried by the joint stock 51 (arm A1 and joint stock 51 are not keyed; arm A1 is also connected to the housing part 551 - which connection is not shown in the figure - and therefore is stationary). Gears G₂ and G₃ freely revolve on the joint stock 51 and can be mutually connected/disconnected by the clutch MDC. Generally, the gear G₁' (that is freely revolvable and - by the actuator ACT - axially movable on its supporting pin) is not meshed with the gears G₁ and G₂' (dashed lines) while the gears G₂ and G₃ are connected (clutch MDC engaged) - which means the run ahead. The clutch MDC disengaged and gear G₁' meshed with the gears G₁ and G₂' - means the run astern. In Fig. 56, the gears G₂ and G₃ revolve freely on the sleeve SL1 on the joint stock 51. The gear G₂ can be connected with the sleeve by the multidisk (or other) clutch MDC (AMDC, not shown in the figure, is the actuator of MDC). Drum DR is carried by the stocks SS of the satellite bevel gears SG fixed in the sleeve SL1 and thus revolves with the sleeve SL1. It can be blocked by band BD (ABD is hydraulic or other actuator of the band BD). Satellite gears SG are meshed with the bevel gears GG₂ and GG₃ fixed to the gears G₂ and G₃, respectively. Now the neutral position, ahead run and astern run are obtained for the actuators AMDC-ABD being idle-idle, active-idle and idle-active, respectively. To note is that the bevel gears SG, GG₂, GG₃ may be substituted by spur gears, cf. Fig. 57. In this case the astern drive speed is reduced to n(G₃) = n(G₂)·D(GG₂)/D(GG₃) = n(G₂)·z(GG₂)/z(GG₃) (where n = RPM, D = diameter, z = number of teeth). It is worthwhile to note in Figs. 55 and 56 that the gear G₁ is held by the stationary arm A1 carried by the joint stock 51 while the driving shaft 23 is connected to it by the flexible coupling CG₁ (evidently, the latter coupling CG₁ is the f lexible c oupling at the i nput = FCI). This, together with the f lexible c oupling at the o utput FCO = 292 (between the shafts 25i and 25) makes it that the reduction gearbox joint 5G as a whole is well protected (vibration, misalignment, etc.) both at the input and output - which may be set forward as a generally advisable measure. The shaft 25i is hollow in both of the mentioned figures. This shaft, together with the gear G n = G₄ and the forward "half" of the flexible coupling 292 = FCO, is carried by the pin A4 that is held (cf. arm A2 in Fig. 55) by the joint stock 51. (This is similar to the case of Fig. 24 except that the arm 3A is forged there with the joint stock 51). Considering also the arm A1 supporting the gear G₁, it is seen that the requirement for all the gears G₁, ..., G n to be carried by the joint stock 51 is met in Figs. 55 and 56. The turning of the joint's pivoting assembly is performed through the bearing LZ and wedges WD, W1 in Figs. 55 and 56, respectively. To note is that some compacts can be sustituted with the ship afloat. For example, in the case of the horizontally tunneled "compacts" where the tunnel 55T is a constituent of the compact while the tunnel's guide 55TG belongs to the stern's structure, the shaft line is first disconnected for the forward end of the tunnel's guide 55TG to be closed with the cover 55TC, Fig. 58,a, and then the old compact is pulled out and the new one inserted. With the new compact in and the cover 55TC off (in order to connect the shaft line) there is a slight leakage around the tunnel 55T only until the seals in the stuffing boxes 55SB are tightened (or until the other sealing devices applied are fixed). The leakage may be greately reduced if the tunnel 55T and its guide 55TG are made slightly coned (so that the leakage practically vanishes when the tunnel has been completely inserted). The coning may relate either to the whole length (Fig. 58,b) or only to the forward end of the tunnel and guide (Fig. 58,c). Then, the compacts with tunnelless housings can also be substituted while the ship is afloat. For this reason, the (full or hollow) connecting element 55E of the joint housing 55 in Fig. 59 (which element substitutes for the housing bush 55B and carries the driving shaft 23) is ended with cone CN that, in mounting the compact (by its horizontal shifting), is firmly seated in its coned bearing CNB (in the ship's stern) by tightening the nut NT (which is done from the inside of the hull). In dismounting the compact with the ship afloat, the (preferably flexible) coupling 292F is first dismantled, then the protective nylon (or other) bag NB is fitted (to protect the fore end and bearing B23 of the shaft 23 when in water), the cover CTN (put in the gap GP between the shafts) is fixed to the tunnel TN whereupon the compact is shifted horizontally backward (dismantling) while the tunnel room TN is getting filled with external water. (The cover CTN may have some screws whereby the initial push is given to the connecting element 55E if its cone has stuck in the bearing CNB.) In mounting, the (new) compact is shifted horizontally forward till its cone CN sits (like a cork) in its bearing CNB (the cover CNT may have a viewing glass for inspection), then the tunnel room is drained (opening DR) and the cover removed, whereupon the nut NT is put in its place and tightened, the nylon bag NB removed and the coupling 292F fixed. [The tunnel TN is axially movable along and fixable to the outside of the coned bearing CNB; when not used, it may be shifted backward (dashed lines). Depending on the type of the coupling 292F, the shaft 23F may or may not be shifted axially.] Fig. 60 shows an RSPC (similar to that of Fig. 38) with the connecting element 55E provided with the channels CLB for lube oil, for oil (air) to actuate the clutches MDC, etc. (the nut NT is provided with "sprockets" SPR with sufficient room in between to connect the hoses HS to the channels CLB; the axes of the cone CN and driving shaft 23 are displaced). The tube 552T (fixed to the pivoting part 552) is as long as to make it that, on an unloaded draught (and possibly with the ship trimmed by the head) the radial bearing 36H and double slider coupling 513 are near the water level so that they can be manipulated (opening/closing the buckle bearing 36H, disconnecting/connecting the double slider coupling 513 and pulling up/down the steering stock 3) from a raft (without the aid of a diver). The wedge WD connects the pivoting part 552 with the joint stock 51 so that the joint pivoting assembly and the propeller supporting elements (bearing 34, jacket 33J, etc.) pivot together. [The steering gear 32 (that turns the steering stock 3, not shown in Fig. 60) is on (or near) the stern deck; 33CV is a cover to the rigid jacket 33J to mount the flexible coupling 292; elements 33FL and 55FL are "filling bodies" fixed to the jacket 33J and housing part 551, resp.] Full lines and full lines plus dashed lines present the outside-hull and through-hull cases, resp. (in the latter case it is only the stock 3 that is passed through the tube 35 so that the said tube may be quite narrow). If, for a good access of water to the propeller, a "well" 120 is formed before it, Fig. 61, for which purpose the driving shaft 23 is let to stretch considerably behind the stern tube 24 making it necessary to provide the strut bearing 244 in front of the propeller 26, then the situation is generally as follows: (a) Strong strut bearing 244 substitutes for the stern tube 24 and thus the bush 55B of the joint's housing 55 is shrunk on it (or on its aftward extension); or, the stern tube 24 is extended from the stern 11 and passed through the strut bearing 244 so that its end carries the bush 55B - as in Fig. 56. In both cases the bush 55B may be substituted by the connecting element 55E (which, after all, holds generally). (b) Strong strut STR provides supports to the rudder stock 3, attachment 159 of the housing 55, etc. and yields some general protection to the RGJ 5G (in running ahead) substituting thus for the stern (transom) 11 (additionally, it may be used also as an access to the joint 5G). Points (a) and (b) indicate that a number of the previous units can be mounted on the strut bearing 244 and to the strut STR. For example, in Fig. 61 there is the RSPC of Fig. 42 fitted to them. If the aftermost part 11A of the stern is bolted (or otherwise dismountably connected) to the main portion of the stern, then this is an "outside-hull" case. If not, then the solutions for the "through-hull" cases are applicable (tubes 551, 552 inserted from above through the tube 35 and then fixed to the joint; elliptical tube 35; etc.). Longitudinal recesses in the integral stern may also be made to install horizontally the RSPC in hand. The strut STR, tube 552 and jacket 33J are made as a well-formed streamlined whole (see Section A-A). For course stability, the well 120 may be parted by a skeg whose lower edge (dashed line) may or may not involve the shaft 23 (yielding thus a good shaft protection in the former case). A wide but hollow skeg may merge with both the strut STR and just mentioned shaft protection and thus possibly provide an access chamber to the joint (access horizontal or oblique). In general, any vertical or oblique access tube, if properly fixed to the stern 11, may be used as an independent substitute strut yielding the strut bearing 244 to the driving shaft 23 extending from the stern tube 24. Or, if there is a proper strut STR just in front of the access tube then it may be merged in some way with that tube. If, instead of the bush 55B, there is the cone-shaped connection element 55E (for the purpose of substituting the compact while the ship is afloat), then the arrangement is as in Figs. 62,a,b,c where the tube 24E connects the strut bearing 244 and the standard stern tube 24 (the forward end of the tube 24E is inserted into the stern tube 24). The tube 24E contains the inner tube 24I with bearings BR1, BR2, BR3, BR4 and driving shaft 23F. By the screw threads ST1 and ST2, the inner tube 24I is connected, at its aft and fore ends, with the forward extension 55EX of the cone-shaped connecting element 55E and stationary tube 24E, Figs. 62,b and 62,c, respectively. When dismounting the compact, the tube 24I is first turned (by the nut NT and counter-nut CNT blocked to it or otherwise) and thus shifted (together with the shaft 23F and its bearings BR1-BR4) forward (on the threads ST1 and ST2) whereby the inner tube 24I and extension 55EX and also the spline SPL get disconnected (the short shaft 23B has been previously taken out of the shaft line). Then, while the spline SPL and its chamber CSP are being well greased (through pipes and channels PCH), the old compact is taken out. When the new compact, provided with a protector on its female spline-SPL part, has been put in the cone-shaped bearing CNB, then the inner tube 24I is turned in the opposite direction and thus shifted (together with the shaft 23F and its bearings) aftward (on the thread ST2) whereby the inner tube 24I and extension 55EX get connected (thread ST1) while also the said protector is pierced and spline SPL gets connected which is followed by the cone-shaped connecting element 55E getting tightened in its bearing CNB (by tightening the nut NT against the stationary tube 24E so that the tubes 24I and 24E get to be extended and compressed, resp.) Pipes and channels PCH serve for greasing, flushing, etc. the spline SPL and its chamber CSP; SHO is a streamlining hood; stock 3 is connected with the pivoting housing part 552 by a double slider coupling or otherwise; strut STR and housing 55 (and also stock 3) may form a streamlined whole. Considering the connection of the joint 5 with the ship's stern, there is a general remark to the case of the joint's housing 55 being only shrunk (by its bush 55B) on the stern tube 24 (Figs. 38, 54, 55, etc.). Namely, the housing 55, jacket 33J and propeller 26, taken together, appear then as a horizontal cantilever (so that the end of the shaft line turns out to be a Grimm's shaft) with some deflection at its free end. The deflection mentioned can be reduced by providing the housing 55 with the lower and upper bearings 55L and 55U, resp., around the common axis V - such as in Fig. 56 where the housing 55 is held by the strut STR acting as a "wrench" (the bearings 55L and 55U are "radial" housing bearings providing the counter-tumbling moment while the cantilever's weight is still being transmitted to the stern tube 24 by the bush 55B). If the housing is close to the stern (no strut case) then the lower and upper housing bearings are held by the sternpost heel and sternpost, respectively. The other solutions are possible as well (for example, the buckle bearing 36H in Fig. 60 substituting for the bearing 55U). The "wrenchlike" holding of the joint's housing 55 is generally recommendable. The cone-shaped jacket (elastic, 33J'; rigid, 33J) enclosing the propeller shaft space 570 and connecting the propeller-shaft bearing 34 with the joint's housing 55 is worthy of a special consideration because it performs several functions. Namely, it yields a general protection to the propeller shaft 25 (and the aft portion of the joint's horizontal shaft 25i together with the output flexible coupling OFC = 292, if any); it serves as a "stern bulb" for a good induction of water to the propeller (the joint's housing 55 and jacket produce a streamline whole); when rigid (33J), it transmits the propeller's weight and thrust to the joint's housing 55 (or to its stationary part 551), which housing (part) is thus included in the propeller-shaft carrier 331 whereby the "compacts" are enabled; it makes it that the window 5510 of the stationary housing part 551 and the passage of the propeller shaft 25 or shafting 25,25i through the pivoting housing part 552 [which shaft(ing) and housing part pivot jointly with the third and fifth variants] - should not be sealed (due to the propeller-shaft space 570 being waterproof on account of the jacket). Hence, this jacket performs three and four functions with the one-part and two-part housing variants, respectively. Although not drawn in our figures wherever feasible (to note is that it can be easily fitted instead of the curved levers 33, 33L or across them), the closed jacket in hand is applicable to all the "housing variants" elaborated (as such, this pivotal and non-revolving jacket turns out to be an additional element of unity of all of them). Thus, it connects the propeller-shaft bearing 34 with the pivoting element of the joint's housing (or the housing as a whole if it is pivoting), i.e. with either the arced plate 6 (Figs. 19, 20, 23) or riding band 6BR (Fig. 52) with the "second variant" or the pivoting housing part (552) with the "third variant" (Figs. 33, 38, 42, 54-56, 60-62) or the whole housing with the "fourth variant" or the pivoting housing part (calotte) 552 with the "fifth variant". Needless to say, the features mentioned lastly (jacket 33J, "wrenchlike holding" of the housing 55, etc.) can be combined. 4.4. Additional comments on the prior art After the above presentation some additional comments will be given here on the prior art - now in a direct comparison with the solutions proposed in this application. In doing so, we are obliged to comment foremost the gear joint of Questiaux (Fr 1156779) since of all the gear joints of the aforementioned prior art it is the only one that is put in a single and compact housing - which is the case of our RGJs, too. The joint of Questiaux is presented in Fig. 63 (taken from the application of Questiaux, designations ours) which is selfexplanatory. Note should be taken only that the transmission ratio of this joint is r g ≡ 1 and that the shafts 23 and 25 are necessarily coaxial (axial displacement a ≡ 0). Thus, while with our gear joint there may be r g 1 and a (axis displacement) 0 (we are mostly interested in r g > 1 and therefore call it the reduction gear joint) - with the gear joint of Questiaux there is only r g ≡ 1 and a ≡ 0. Hence, no possibility of reduction of shaft speed is a great drawback of the gear joint of Questiaux. This is, however, not the end of its deficiencies. For, although basically made to perform the steering angle ± α between the axes of the driving shaft 23 and propeller shafting 25, the gear joint of Questiaux is not able to do exactly that. Namely, its gear G₄ = G n has simultaneously two active meshing points, the upper point G₄-G₃ and the lower one G₄-G₂, which points should be the "travelling points" in the steering pivoting ± α . However, in an endevour to make the steering angle α , the upper and lower meshing points would impart to the gear G₄ and shaft 25 simultaneously a clockwise and an anticlockwise "additional" or "steering" rotation which actually means that the gear G₄ and shaft 25 are blocked to make a pivotal motion α ; or, that the meshing points cannot be the travelling points. In other words, only the steering angle α ≡ 0 (or any other fixed angle) is possible with the joint in hand, which angle then, evidently (since unchangeable), is no "steering" angle at all. Hence, the gear joint of Questiaux is a failure as a joint to be applied in the rudder-propeller drive. To make it a joint, one of the said meshing points should be cancelled. Thus, by omitting either the gear G₂ (cancelling meshing point G₄-G₂) or gear G₃ (cancelling meshing point G₄-G₃) one obtains rightaway a joint (which, in addition, makes possible both r g 1 and a 0), in fact - one obtains our RGJ. To note is also that no comment has been given in the application of Questiaux on the sealing of the housing. Putting aside this omission, we conclude that the only way to construe the single two-part housing of Questiaux is that the forward and aft parts of its housing are vertical cylinders truncated aft and forward, respectively. In this case the sealing occurs in or near the main meridional plane (MMP) and the vertical seal applied is necessarily rectangular - hence "irregular". Such a seal, when acting against the surfaces moved perpendicularly to its plane (as the case is here), - is unreliable (particularly in the corners of the rectangle). To obtain regular, i.e. standard circular seals, the housing parts should be spherical calottes which then is the case of our two-part (two-calotte) housings with the sealing in or near the MMP. [Mention may be made here that we also use two-cylinder housings (cf. Figs. 16, 22, 36-38, 40-43, 52, 53, 60, 61, etc.) with vertical cylinders which are, however, complete, i.e. not truncated and where the seals are horizontal and circular (regular) for which is necessary that the axes of the driving and driven shafts are displaced ( a >0 or a <0) in order to put the seal within the said displacement - while with the joint of Questiaux there is no axis displacement.] Hence, the gear joint of Questiaux is inferior to our RGJ regarding both the "interior" (the joint itself in the housing) and "exterior" (the housing, its sealing, etc.). The discussion of the "joint" of Questiaux being thus completed, let us contrast now the solutions proposed here with the remaining gear-joint prior art (applications of Barrere Fr-6183319, Lefebvre Fr-645087 and Basset Fr-637613). In doing so, let us note that the joints offered in the said applications are located in several housings which are either distant from each other or are simply leant against one another ("joint complexes") so that the installations offered turn out to be room spending and generally inconvenient regarding a proper flow of water towards the propeller. This ensued as a consequence of no particular attention being paid in the prior art to set up a joint in a single and compact housing. Putting aside the case of Questiaux, it is only our solutions presented here which are geared up towards that aim. Then, the compactness of the housing striven for here (which yielded the overlapping of the housing parts, slot, sealing, etc.) imposed also a "condensed" design of the very interior of the housing, i.e. of the joint itself. This, together with some other aspects, yielded further distinctive features of our gear-joint variants, viz.: a special way of supporting shafts and gears achieved by the vertical arborescent torqueless joint stock 51 and its arm(s) 53, 53L carrying the gears and joint's horizontal shaft 25i; no vertical torque-transmitting shaft(s) within the joint; wide streamlined multi-purpose jacket 33J attached to the pivoting housing part forming a stern bulb, accomodating a flexible coupling 292 and transmitting the propeller's thrust to the housing 55 and stern 11 by passing it around the gears of the joint; couter-rotating gears G₄ and G₄ ' with their clutches MDC providing reversibility of the joint; joint stock's assembly made in the way to enable its easy interchangeability. Neither of the above features is met in the prior art. Thus, the above lines show that both the very joint ("interior") and the housing ("exterior") of our gear-joint variants (i.e. of the second, third and forth variants) are clearly different from the prior art. As for the fifth variant, the fact is that the hydraulic joints as such do not appear in the prior art at all so that the fifth variant is not affected by the said art either. At the end, let us give a general view of the ship installation as a whole and of our variants in its framework. Basically, the scope of the present patent application involves three main topics: joint, housing and fixation of the housing to the ship stern (propeller-shaft carrier 331). These three topics keep being intermingled with each other in the application. This fact, together with a general view at the ship installation as such (where it is the housing and its fixing to the ship what duely comes first to the sight rather than the joint as the housing's interior), hence this "installation awareness" - makes it that we faced four variants of the ship installation to be claimed, viz.: the second variant relating to a one-part stationary housing with a horizontal aft sealed window (slot) 550A (Figs. 13,b, 18, etc.); interior: RGJ; the third variant relating to a two-part housing with the stationary and pivoting parts 551 and 552, resp. mutually sealed and with the window 5510 in the stationary part (Figs. 13,c-e, 33, 38, 42, etc); interior: RGJ; the fourth variant relating to a one-part pivoting housing with a horizontal forward sealed window 550F (Figs. 13,f, 39); interior: RGJ; the fifth variant relating to a two-part housing with the forward stationary and aft pivoting calottes mutually sealed (Figs. 13,g, 44-48); interior: hydraulic joint, three kinds of them; (while the first variant - application of the universal homokinetic joints - was used here for the introductory purposes only). Thus, it is a focusing of our attention upon the ship installation as such that made it that the same RGJ 5G, when put into three basically different and differently sealed and fixed housings, yielded three variants of the ship installation (the second, third and fourth variant) while three different hydraulic joints 5H put in the same housing yielded just one variant of the ship installation (the fifth variant).

Claims: Ship installation with a rudder propeller driven by a generally horizontal shaft line comprising a joint (5) at the stern end of the shaft line (23) mounted in a housing (55) being fixed to the stern (11), a generally horizontal propeller shaft (25) being generally parallel to the shaft line (23) wherein the propeller shaft (25) is connected with the housing (55) and pivotal around a vertical axis (V) of the joint (5), characterized in that the joint (5) is a gear joint (5G) consisting of a first pair of bevel gears (G1 and G2) and a second pair of bevel gears (G3 and G4, G4') wherein all the pairs of bevel gears mesh in one gear joint (5G) which is arranged in one closed housing (55), the said hausing (55) comprises a generally cylindrical inner stationary housing part (551) and coaxially thereto a generally cylindrical outer housing part (552) which overlaps with its open end the inner housing part (551) and is pivotal around the common central vertical axis (V) of the gear joint (5G) and the housing (55), the inner stationary housing part (551) comprises an opening for the propeller shaft (25) formed as a horizontally extending slot (5510), the housing (55) comprises a circular seal (62E) horizontally arranged between the cylindrical walls of the inner housing part (551) and outer housing part (552) below/above the horizontal slot (5510) and above/below the incoming shaft line (23), thus defining an axis displacement (a) between the propeller shaft (25) and the shaft line (23), a jacket (33J) extending from the pivoting housing part (552) to the propeller (26), which jacket has a generally cone-shaped form, is fixed to the pivotal housing part (552) with its broad base, carries the propeller shaft (25) supported by bearings, wherein at least one bearing is a thrust bearing (342) provided in the propeller-adjacent part of the propeller shaft (25), the vertical axis (V) of the gear joint (5G) being central and coaxial to the housing (55) defines a vertical arborescent torqueless joint stock (51) with a horizontal shaft (25i), the joint stock (51) generally supports all gearwheels (G1, G2, G3, G4, G4') of the first pair of bevel gears (G1 and G2) and of the second pair of bevel gears (G3 and G4, G4'), the horizontal shaft (25i) supports the counter-rotating driven gearwheels (G4, G4') of the second pair of gears (G3 and G4, G4'), wherein these counter-rotating gearwheels (G4, G4') rotate freely around the horizontal shaft (25i) on opposite sides of the joint stock (51), means (MDC) are provided for engaging independently one of the counter-rotating gearwheels (G4 or G4') with the horizontal shaft (25i) in a torque-transmitting connection and disengaging the other one or both of the counter-rotating gearwheels (G4, G4') to provide a reversability of the direction of rotation of the propeller shaft (25), and the said joint stock (51) together with the gearwheels (G1, G2, G3, G4, G4'), the horizontal shaft (25i) and the said connecting means define an interchangeable assembly in the stationary housing part (551). Ship installation with a rudder propeller driven by a generally horizontal shaft line comprising a joint (5) at the stern end of the shaft line (23) mounted in a housing (55) being fixed to the stern (11), a generally horizontal propeller shaft (25) being generally parallel to the shaft line (23) wherein the propeller shaft (25) is connected with the housing (55) and pivotal around a vertical axis (V) of the joint (5), characterized in that the joint (5) is a hydraulic joint (5H) containing heavy and/or viscous fluid and consisting of coupling elements for an hydraulic transmission of torque from the driving shaft (23) to the driven or propeller shaft (25), the said hydraulic joint (5H) is located in a two-part spherical housing (55) consisting of a pivotal spherical calotte as the aft part (552) and of a stationary spherical calotte (551) as the forward part, so that the propeller shaft (25) and the aft housing part (552) can pivot by a steering angle (± α ) around the pivoting axis through the centre (C) of the spherical housing (55), with the housing parts (551, 552) overlapping one another and being mutually sealed. Ship installation with a rudder propeller driven by a generally horizontal shaft line according to Claim 1, characterized in that the horizontal shaft (25i) carrying the vertical counter-rotating bevel gears (G4, G4') is supported: in one case, by a bearing (522) in the joint stock (51) with the said shaft passing through the joint stock (51) so that the latter is duely pivotal; in another case, by bearing(s) (52, 52L) outside the joint stock (51), which bearing(s) is/are by means of curved arm(s) (53, 53L) or brackets connected with bearing(s) (54, 54L) on the joint stock (51) with the said stock being pivotal only if the latter bearing(s) is/are keyed to it; whilst, in the case of only one bevel gear (G4) on the joint's horizontal shaft (25i), the latter shaft - besides the ways of supporting it as in the case of two bevel gearwheels (G4, G4') on it - is supported: in one case, by a horizontal pin (521) offered by the said joint stock (51), on which pin rides the hub (520) of the horizontal shaft (25i) so that the said joint stock (51) is pivotal; in another case, by a bearing (52) being fixed to the pivoting housing part (552) with the joint stock (51) being pivotal only if the pivoting housing part (552) is keyed to it. Ship installation with a rudder propeller according to Claims 1 and 3, characterized in that a vertical stationary tube (551), closed from below, is - by a horizontal bush (55B) or connecting element (55E) near its bottom - fixed to either the stern tube (24) or strut bearing (244), in general to the ship's stern (11), and held by a horizontal radial bearing (36H) fixed, above the water level, to either the stern (11) or strut (STR), respectively, the said stationary tube (551) is embraced by a pivoting vertical tube (552) extending from just above the bush (55B) or connecting element (55E) to just below the radial bearing (36H), to which pivotal tube is fixed either a rigid cone-shaped jacket (33J) or curved or other lever(s) (33, 33L) carrying at its/their aft end the propeller-shaft bearing (34, 342); while the pivoting tube (552) is either hung on a foothold (6FH) of the stationary tube (551) located below the said radial bearing (36H) or supported by such a foothold located above the bush (55B) or connecting element (55E); a horizontal seal (62E) at the lower end of the outer pivoting tube (552) blocks the access of water in between the said tubes; a joint (5) is located on the bottom of the stationary tube (551), the lower portion of that tube thus being the said joint's stationary housing part; the horizontal slot (5510) in the stationary tube (551) for the passage of the propeller shaft (25) is covered by the closed jacket (33J) the stationary tube (551) is also provided with an inside ladder (LD) for access to the said joint; while the outer pivoting tube (552) is turned by a steering gear (32) or manually. Ship installation with a rudder propeller according to Claim 4, characterized in that the gear joint (5G) is accomodated in a cage (CG) which is slidable in vertical guides (GCG) in the ambient stationary tube (551) and fixable at its bottom so that the joint is then connectable both with the incoming driving shaft (23) and outgoing propeller shaft (25) which all enables a substitution of the caged joint as a whole. Ship installation with a rudder propeller where the the gear joint (5G) and housing (55) are generally as in Claims 1 and 3-5 but which is characterized in that instead of by the vertical joint stock (51) and its arm(s) (53, 53L), the joint's horizontal shaft (25i) with its counter-rotating vertical bevel gears (G4, G4') and their means for engaging/disengaging (MDC) is carried by a horizontal ring (RG) which is pivotal in its plane while being supported by horizontal circular or circular-arc guides (GRG) fixed to the inside of either the housing (55) or its stationary part (551), the said horizontal ring (RG) offering a forward and an aft bearing (BRF, BRA) to the said joint's horizontal shaft (25i) passing diametrically across the housing (25); whilst the axes of the said horizontal ring (RG) and its guides (GRG) coincide with the vertical axis (V) of the housing (55). Ship installation with a rudder propeller and the gear joint (5G) according to Claims 1, 3 and 6, characterized in that the joint's housing (55), instead of consisting of the generally cylindrical housing parts (551, 552), is made as a spherical two-part housing (55) consisting of a forward housing part (551) which is a stationary calotte fixed to the ship's stern and of an aft part (552) which is a pivoting calotte fixed to either the stationary calotte (551) or the pivoting assembly (331T) of the propeller shaft carrier (331) so that it is pivotal around the generally vertical pivoting axis through the centre (C) of the spherical housing (55), the said forward calotte being either open in its aft portion or having a horizontal aft slot (5510) there for the passage of the propeller shafting (25, 25i), which shafting passes normally through the said aft calotte and travels together with it sidewise when steering; the two calottes (551, 552) overlaping one another and being mutually sealed with vertical circular seals (62M) in the transverse meridional plane. Ship installation with a rudder propeller containing a gear joint (55G) as in Claims 1, 3 and 6 which is characterized in that the stationary housing part (551) of the gear joint (5G) is provided with an aft horizontal slot (5510), which part is either shrunk by its bush (55B) on the stern tube (24) or is by a cone-shaped connecting element (55E) fixed to the ship's stern (11) or strut bearing (244); while the pivoting housing part (552), being generally of the same form as the stationary housing part (551), embraces the latter part and is provided with a horizontal forward slot (552W) whereby it rides over the said bush (55B) or connecting element (55E); the forward slot (552W) being sealed by a stationary vertical but in the horizontal plane circularly arced plate (6F) fixed to the bush (55B) or connecting element (55E), which plate is located in guides (56F) fixed to the said pivoting housing part (552), the said guides and the pivoting housing part being also provided with forward-slot seals (S1, S2) circumventing the said forward slot (552W); while the said aft s[ot (5510) of the stationary housing part (551) is also provided with a seal (S4) circumventing it, the chambers between the said seals being filled with oils from overhead tanks. Ship installation with a rudder propeller where the gear joint (5G) is as in Claims 1, 3 and 6 but which is characterized in that its housing, instead of being a two-part housing, is a closed one-part housing (55) whose forward portion is fixed to the ship's stern (11) so that the said housing (55) is stationary while its aft portion is provided with a horizontal sealed aft slot (550A) extending sidewise as required by the steering angle of the outgoing propeller shafting (25, 25i); with the said aft slot (550A) being sealed: in one case, with at least one vertical but in the horizontal plane circularly arced plate(s) (6), which plate(s) by its/their sealing collar(s) (60) ride(s) on the propeller shafting (25, 25i) and thus travel(s) sidewise with it by the steering angle while covering thereby permanently the said aft slot (550A) which is circumvented by stationary seal(s) (62) pressed against the said arced plate(s) by mechanical or similar springs (61), inflatable hoses or the like, all of the said elements being located in horizontal circular-arc guides (56e, 56i) of the said housing (55); in another case, with a full-circle band (6BR) which by its sealing collar (60) rides on the outgoing propeller shafting (25, 25i) and travels with it by the said steering angle while riding also on the stationary joint's housing (55) which is cylindrical in the range of the band (6BR), the said band being sealed against the housing (55) above and below the said propeller shafting by means of the horizontal circular seals (62EU, 62EL) or packings fitted in the horizontal full-circle guides (56), then by the entry seal(s) (ES) at the ends of the riding band (6BR) as well as by the very seats (6SL) of the band. Ship installation with a rudder propeller where the gear joint (5G) is as in Claims 1, 3 and 6 but which is characterized in that its housing, instead of being a two-part housing, is a closed one-part housing (55) fixed to the pivoting assembly (331T) of the propeller-shaft carrier (331) so that the said housing (55) is pivoting while its forward portion is provided with a horizontal sealed forward slot (550F) extending sidewise as required by the steering angle; with the said forward slot (550F) being sealed: in one case, with at least one vertical but in the horizontal plane circularly arced plate(s) (6), which plate(s) by its/their sealing collar(s) (60) ride(s) on the stationary driving shaft (23) and thus is/are stationary while being located in guides (56e, 56i) of the pivoting housing (55), the said guides being provided with seals (62) circumventing the said forward slot (550F) of the housing (55); in another case, with a face seal (172F) which encompasses the said forward slot (550F) from outside and is supported and pressed against the joint's housing (55) by a slot protector (171F) which is a closed structure protruding from the near-by stern (11) of ship. Ship installation with a rudder propeller driven by a generally horizontal shaft line according to Claim 2, characterized in that the hydraulic joint (5H) is an hydraulic centrifugal joint whose coupling elements are a set of inner blades (IB) which are generally longitudinal radial plates with external semicircular contours carried by the driving shaft (23); and a set of generally longitudinal peripheral blades (PB) whose internal contours are also semicircular, the latter blades being at their external contours carried by a hollow sphere (SH) fixed to the driven or propeller shaft (25); the two sets of blades are concentric to the centre (C) of the housing and define a radial gap between their adjacent semicircular contours, the said sphere (SH) and peripheral blades (PB) having a forward conical space opening (OP) formed as a cut out "conical space" whose apex and axis lies in and passes through the center (C) of the housing (55), respectively, the said axis being coaxial with the propeller shaft's (25) axis; while the housing (55) is filled with heavy fluid. Ship installation with a rudder propeller according to Claim 2, characterized in that the hydraulic joint is an hydraulic multisphere friction joint whose coupling elements are a set of concentric spheres (B23) fixed to the driving shaft (23) having an aft conical space opening (OP); and a set of concentric spheres (B25) fixed to the driven or propeller shaft (25) having a forward space opening (OP); wherein both sets of spheres are concentric to the centre (C) and the spheres are intermingled in the way that in the space between two successive spheres of one set there is one sphere of the other set with the spheres being close to each other; while the housing (55) is filled with viscous fluid. Ship installation with a rudder propeller according to Claim 2, characterized in that the hydraulic joint is an hydraulic whirl joint whose coupling elements are at least one inner sphere (S23) on the driving shaft (23), which sphere is provided with external meridional grooves (SGt3) or ribs and an aft conical space opening (OP); and at least one outer sphere (S25) fixed to the driven or propeller shaft (25), which sphere is provided with internal meridional grooves (SG25) or ribs and a forward conical space opening (OP); wherein the "poles" of groove or rib "meridians" of each of the said spheres lie in the axis of the respective shaft; while the housing (55) is filled with heavy fluid. Ship installation with a rudder propeller according to Claims 1-13, characterized by a plurality of arrangements to fix the joint's housing (55) or its stationary part (551) to the ship's stern, such as: by the said housing (55) or its part (551) being shrunk by its bush (55B) on the stern tube (24) and fixed to the stern (11) by the joint's access tube (165) and attachment (159); by it being shrunk by its bush (55B) on the strut bearing (244) and fixed to the strut (STR); by it being by its horizontal tubular extension or tunnel (55T) inserted and fixed in the sealed structural tunnel guide (55TG) in which case the said tunnel contains a quasi stern tube (24Q) or bearings (BF, BA) of the "open" driving shaft (23) and even the engine (2) itself which may also be mounted on an open forward extension (FE) of the lower side of the said tunnel; by it being shrunk on the stern tube (24) and, if there is an oblique or other access tube (165) protruding from the stern (11), then by being fixed to it by some flange, face or similar connection (158); by it being fixed by the "lowering tube connection" if there is a vertical structural tube (55S) in the stern (11) in which case an intermediate tube (55t) fitted in the said structural tube is - after the joint housing (55) or its stationary part (551) has been horizontally shrunk on the stern tube (24) - lowered down into the housing (55) and then fixed to it; by it being shrunk on the stern tube (24) and supported by a stool (ST) if the stern (11) or transom is vertical, the said stool being an extension of the stern, while the housing's tubular vertical extension, i.e. its pivoting part (552) yielding access (160) to the joint is held by horizontal bearings (36H) fixed to the stern, which bearings hold the said tubular vertical extension and thus the housing parts themselves; by seating the forward cone-shaped connecting element (CN) of the housing (55) in its coned bearing (CNB) in either the stern (11) or strut (STR); a number of the above cases of joint with its fixing arrangement yielding a compact', i.e. a self-contained unit which is easily mountable into or onto and dismountable from the ship's stern. Ship installation with a rudder propeller according to Claim 14, characterized by the possiblity to substitute, while the ship (1) is afloat, the compacts (RSPC) provided with a forward horizontal tunnel (55T) in the tunnel guide (55TG), for which purpose the shaft line is disconnected and then a cover (55TC) is fixed to the forward end of the structural tunnel's guide (55TG), which guide is flooded during the substitution of the horizontally shifted compacts (RSPC) whilst after the substitution the said cover is removed and the shaft line connected; with, upon removing the cover (55TC), a slight leakage of external water between the tunnel and its guide only until the stuffing boxes (55SB) or other tunnel seals are tightened; and with, to reduce the said leakage, both the compact's tunnel and its guide being slightly coned either all along their lengths or only at their forward ends. Ship installation with a rudder propeller according to Claim 14, characterized by the possibility to substitute, while the ship (1) is afloat, the tunelless compacts (RSPC) which are shifted horizontally in mounting/dismounting; for which purpose the compact's connecting element (55E) is provided with a forward cone (CN) to be seated in the coned bearing (CNB) of the ship's stern (11) and tightened there from inside the hull by a nut (NT); so that the substitution of an old compact starts by removing the said nut (NT), by fixing the tunnel (TN) to the outside of the coned bearing (CNB) and, upon disconnecting the shaft line, by fitting the cover (CTN) to the forward end of the tunnel (TN) whereby a closed tunnel room is formed to be flooded during the substitution; while, in the process of substitution, after the new compact's cone (CN) has been seated tightly in the coned bearing (CNB), the said room is drained, the cover (CTN) removed and the nut (NT) tightened whereupon the shafts of the shaft line are connected by their coupling (292F); with the fore end of the compact's driving shaft (23) within the connecting element (55E) and its bearing of both the old and new compacts (RSPC) being protected by a nylon or similar bag (NB) fixed to the front side of the said cone (CN) before the substitution and removed thereafter. Ship installation with a rudder propeller according to Claim 16, characterized by the possibility to substitute the compact (RSPC) carried by the strut bearing (244) while the ship (1) is afloat owing to the stationary tube (24E) connecting the strut bearing (244) and the stern tube (24) and containing the inner tube (24I) with bearings (BR1, BR2, BR3, BR4) of the driving shaft (23F), the latter shaft being connected with the compact's shaft (23) by a spline (SPL), as well as to the inner tube (24I) being connected by the screw threads (ST1, ST2) with the forward extension (55EX) of the cone-shaped connecting element (55E) in the strut bearing (244) and the forward end of the stationary tube (24); so that, to dismount the compact, the inner tube (24I) is turned and shifted forward whereby that tube and driving shaft (23F) get disconnected from the said forward extension (55EX) and spline (SPL) of the driving compact's shaft (23) whereupon the old compact is taken out; while, after inserting the new compact into its cone-shaped bearing (CNB), the inner tube (24I) is turned in the opposite direction and shifted aftward so that that tube and driving shaft (23F) get connected with the said forward extension (55EX) and spline (SPL) of the driving compact's shaft (23) of the new compact, respectively. Ship installation with a rudder propeller according to Claims 1, 3-10, characterized in that the gear joint (5G) is protected: from the side of the propeller (26), by a flexible coupling (292) connecting the joint's horizontal shaft (25') and propeller shaft (25) or two parts of the divided propeller shaft (25), which flexible coupling (292) is located in the cone-shaped jacket (33J); from the side of the engine (2), by a flexible coupling (CG1) just before or within the first gear (G1) of the joint (5G).

Inventors: DZODZO, BORISLAV A.
Applicants: DZODZO, BORISLAV A.
Application year: 1988
Main classification: B63H5
IPC codes: B63H25, B63H5