AN ARRANGEMENT IN CONNECTION WITH A SWINGABLE TURN-UP INBOARD/OUTBOARD STERN AGGREGATE FOR A CRAFT

Abstract: An arrangement in a swingable turn-up inboard/outboard stern aggregate (1) for craft with an inboard engine and an outboard driving means (2) comprising a screw (5), where the inboard driving shaft (3) of the stern aggregate (1) for connection with the engine is connected with a screw shaft (4) which is approximately horizontal in a position for use and is mounted in the lower end of a housing (7) by the aid of a transmission shaft (6), which is divided into two sections (6a, 6b) and surrounded by housing (7). The first section (6a) is at one end mounted (8) in the upper end of housing (7) and connected with driving shaft (3), via a first universal joint (A), and is at its other end, via an angular gear (B), connected with an upper end of section (6b) which is inclined rearwards and downwards. The lower end of second section (6b) is connected with screw shaft (4) at a firm angle (V), via a transmission means (C) of torsional moment. In connection with angular gear (B) comprising two sets of angular gearwheels (B1, B2) a reversing means (D) is provided to reverse the direction of rotation of lower section (6b) and, thus, the direction of movement of craft (10).

Description: An arrangement in connection with a swingable turn-up inboard/outboard stern aggregate for a craft. The present invention relates to an arrangement in connection with a swingable turn-up inboard/outboard stern aggregate for craft with an inboard engine and an outboard drive unit comprising a screw, and of a kind as stated in the preamble of the following independent claim 1. Such a stern aggregate is known from the applicant's previous NO-PS No. 158 335, the object of which was to reduce dimensions, especially the transversal dimension, of the lower portion of the housing surrounding the propel shaft and screw shaft with bearings by using universal joints between the propel shaft and the screw shaft. In such a stern aggregate reversal of the direction of screw rotation may either be achieved by the aid of a gearbox in said inboard engine or, if desired, in the transmission from the latter to the stern aggregate. The last mentioned concept will require space between the engine and the stern of the craft and it will also form an independent unit which has to be mounted, i.e. inserted between the stern aggregate and the engine. It is an object of the present invention to provide a stern aggregate where such a gear or reversing means is part of the stern aggregate proper, so that such space as mentioned is saved, and labour for mounting is saved, since only the stern aggregate proper is to be mounted on the craft and connected with the engine. According to the present invention the above object is achieved by the features appearing from the characterizing part of the following independent claim 1, as well as from the following dependent claims. An embodiment of the invention will be disclosed in more detail below with reference to the drawings, in which Figure 1 is a side view and partly a sectional view of the stern aggregate, mounted on the stern of a craft; Figure 2 is a diagrammatical top view of a stern aggregate with a pressure cylinder for lateral displacement of the stern aggregate for steering the craft and with pressure cylinders for turning the stern aggregate up and down into the water. Figure 1 shows an inboard/outboard stern aggregate 1 the fastening means la of which is mounted on the stern of craft 10, and a driving unit 2 which is swingably fastened to fastening means la, via a horizontal transversal axis D (Figure 2) and an approximately vertical axis E, for lifting, and lowering, respectively, of driving unit 2 and for swinging driving unit 2 to steer craft 10 in motion. In fastening means la an inboard driving shaft 3 is mounted for connection with output shaft 3a, via a flange coupling 3b. Via a double universal joint A driving shaft 3 is connected with a transmission shaft 6 which is divided into two sections 6a, 6b. The first section 6a is mounted at the upper end of housing 7 and connected with said universal joint A, and its second end is connected with the second section 6b of transmission shaft 6, via angular gear B. The lower end of section 6b is, via a universal joint C, preferably a double universal joint, connected with a screw shaft 4, which is mounted in the lower rear end of housing 7, with a firm angle V between screw shaft 4 and lower section 6b of transmission shaft 6, which angle V is smaller than 45°, preferably 32°, with an approximately horizontal screw shaft 4. Universal joints A and C may, e.g. be of the ball- and-socket kind which may transmit high moments of torsion relative to its moderate external dimensions. When thin transmission and screw shafts 6, 4 are used at the same time, housing 7 and a lower portion of the same which forms the screw housing 7a, may be built with small transversal dimensions. The screw housing may, thus, be made narrow to reduce its resistance to water flow. The drawing, however, shows that universal joints of the cardan type are used in the present case, and it is especial¬ ly important to be able to use a double universal joint of the cardan type forming a transmission means C for torsional moment between lower section 6b of transmission shaft 6 and screw shaft 4 so as to reduce the bending loads on the universal joint and, thus, to reduce any vibration and loss of transmitted torsional moment to screw 5. Above screw 5 a stabilizing plate 11 is provided. It is fastened to and extends rearwards from housing 7 in an approximately horizontal plane and in the waterline when the craft is in motion. By the aid of pressure cylinders 9, which are fastened to fastening means la and housing 7, below the horizontal transverse axis D, driving unit 2 may be turned up and down and the inclined position of driving unit 2 is adjustable in order to provide the most suitable angle of attack of screw 5 in the direction of motion. In order to swing driving unit 2 about vertical axis D to steer the craft, a pressure cylinder 12 is provided as shown in Figure 2. The above mentioned reversing means for changing the direction of rotation of screw 5 as well as for cutting off the same is designated D and is arranged together with angular gear B connecting upper section 6a of transmission shaft 6 with its lower section 6b. As shown in Figure 1 angular gear B comprises two sets Bl and B2 of conical gears 11a, lib, and 12a, 12b, with driving gears 11a, 12a being mounted to be engageable and disengage- able on first/upper section 6a of transmission shaft 6 and being engaged with the driven gearwheels lib, 12b, which are provided in a mutually non-rotatable engagement with the second section 6b. A conical intermediate gear 12c is arranged between the driving and the driven gear 12a, 12b to provide for opposite directions of rotation of section 6b when one or the other driving gear 11a, 12a is engaged, or disengaged, respectively. In order to achieve said engagement and disengagement of the driving gears 11a, 12a of first section 6a clutches 13, 14 are provided in connection with respective gears 11a, 12a and are controlled from a manoeuvring central 15. Clutches 13, 14 are preferably air-oil actuated, the compressed fluid being supplied, via conduits 16, 17 in housing 7 to annular chambers 18, 19 In section 6a and, via bores 20, 21 in section 6a to a motor (not shown) in each clutch 13, 14. The clutches may be sliding clutches with one set of disks being fastened to section 6a and the other set being fastened to driving gears 11a, 12a, which two sets of frictional disks are made to contact each other by the aid of said pressure motor in each of the clutches 13, 14 by the aid of manoeuvring central 15 which is controlled by suitable means from the driver's seat in craft 10. In the embodiment as shown in Figure 1, annular chambers 18, 19 are provided between driving gears 11a, 12a and may either consist of annular flanges, which are provided on section 6a and cooperate with an annular surface provided in housing 7, and with conduits 16, 17 opening Into a respective annular chamber. The annular chamber, obviously, may consist of annular flanges extending inwards from said annular surface and being in contact with a corresponding external bearing surface on section 6a. From each of said annular chambers 18, 19 bores 20, 21 extend in section 6a to a pressure motor in each clutch 13, 14. The driven gears 11a, 12a on section B are connected with each other in a manner preventing relative rotation, if desired, via splines 6c, and said gears may also be connected with section 6b, via said splines 6c to be mutually non- rotating. This is so to permit movement/elongation of section 6b, among others in case of changes of temperature, without influencing the position of gears lib, 12b relative to the driving gears 11a, 12a, and intermediate gear 12c. A gear pump 22 is provided on section 6a, suitably at the outer end of the latter, and is, via piping 23, 24 connected with the lower portion of housing 7 comprising an oil sump 25 near propeller shaft 4 and bearing 4a, and with manoeuvring central 15. From the manoeuvring central piping 16, 17 extends to annular chambers 18, 19 and clutches 13, 14. From manoeuvring central 15 a return conduit (not shown) extends to oil sump 25 for return of pressure fluid when the manoeuvring central is disengaged, or via pressure valves, respectively, when the manoeuvring central is engaged for forward or rearward motion of the craft, i.e. in one or the other direction of rotation of screw 5. Due to the fact that reversing gear/manoeuvring central 15 has been moved from craft 10 adjacent to the engine or engine shaft, to the stern aggregate and is mounted with the driving means of the latter, the total dimensions are reduced, and an independent component and mounting of the same is avoided. With this arrangement of the reversing means D between the first sectio 6a of transmission shaft 6 and its second section 6b, a reduced torsional moment is achieved with high rpm of the first section of transmission shaft 6 and, consequently, of the first universal joint A between first section 6a of transmission shaft 6 and the driving shafts 3, because angular gears Bl, B2 are designed to be reduction gears. Second section 6b of transmission shaft 6, thus, has lower rpm and a higher moment of torsion for transmission to screw 5. The first section 6a of transmission shaft 6 with associated components may, thus, be designed with smaller dimensions, whereas the second section 6b with associatd components must be designed with larger/stronger components for transmission of said higher momentof torsion.

Claims: PATENT CLAIMS: 1. An arrangement in a swingable turn-up inboard/outboard stern aggregate (1) for craft with an inboard engine and outboard driving unit (2) comprising a screw (5), where inboard driving shaft (3) of stern aggregate (1) for connection with the engine is connected with a screw shaft (4), which is approximately horizontal in a position for use, and is mounted in the lower end of a housing (7), by the aid of a transmission shaft (6) divided into two sections (6a, 6b) and surrounded by housing (7), where said first section (6a) which is mounted (8) at one end in the upper end of housing (7), is connected with driving shaft (3), via a first universal joint (A), and with its other end is, connected with the upper end of section (6b), which is inclined rearwards and downwards, via angular gear (B), and where the lower end of said second section (6b) is connected with propeller shaft (4) at a firm angle (V), via a transmission means (C) of torsional moment, c h a r a c t e r i z e d i n that a reversing means (D) is provided together with angular gear (B) for reversal of the direction of rotation of section (6b) and, thus, screw (5), via a disengaged position in which first section (6a) of transmission shaft (6) is disengaged from second section (6b). An arrangement according to claim 1, c h a r a c t e r i z e d i n that angular gear (B) comprises two sets (Bl, B ) of conical gears (11a, lib and 12a, 12b), the driving gears (11a, 12a) of which are mounted to be engageable and disengageable on first section (6a) of transmission shaft (6) and are engaged with the driven gears (lib, 12b) which are provided in a mutually non-rotatable engagement with second section (6b), a conical intermediate gear (12c) being provided between the driving and the driven gear (12a, 12b) for achievement of an opposite direction of rotation of section (6b) when one or the other driving gear (11a, 12a) is engaged. 3. An arrangement according to claim 2, c h a r a c t e r i z e d i n that the driving gears (11a, 12a) are, alternatively, connected with the first section, via a respective clutch (13, 14) which is controlled by a manoeuvring central (15). 4. An arrangement according to claim 3, c h a r a c t e r i z e d i n that clutches (13, 14) are actuated by a pressurized fluid, the pressurized fluid being supplied, via conduits (16, 17) in housing (7), to annular chambers (18, 19) on section (6a) and, furthermore, via bores (20, 21) in section (6a), to a pressure motor in each clutch (13, 14). 5. An arrangement according to claim 4, c h a r a c t e r i z e d i n that annular chambers (18, 19) are provided between the driving gears (11a, 12a). 6. An arrangement according to one of claims 2 -5, c h a r a c t e r i z e d i n that the driven gears (lib, 12b) are mutually connected and are connected with section (6b) by the aid of splines (6c). 7. An arrangement according to claim 4 or 5, c h a r a c t e r i z e d i n that a gear pump (22) is provided on section (6a), suitably at its outer end, and is, via piping (23, 24), connected with the lower portion of housing (7) comprising an oil sump (25), with propeller shaft (4), and bearing (4a), and manoeuvring central (15), and furthermore, via conduits (16, 17), with annular chambers (18, 19) and clutches (13, 14). 8. An arrangement according to any of the preceding claims, c h a r a c t e r i z e d i n that transmission means (C) for torsional moment between second section (6b) and propeller shaft (4) consists of a double universal joint.

Inventors: LUND-ANDERSEN BIRGER, LUND-ANDERSEN, BIRGER
Applicants: JAICO MARINE A S, JAICO MARINE A.S
Application year: 1991
Main classification: B63H23
IPC codes: B63H20, B63H23