DEVICE FOR PROPELLING A TRACKBOUND UNIT

Abstract: The invention is preferably intended for use with tunnel drive, where extremely great descents are concerned which cannot be managed by means of known technology, e.g. locomotives or trucks. The device of the invention is characterized by at least two drive wheels (5, 5') swingable substantially perpendicularly to the direction of travel, means (7; 7') for drive of the wheels (5; 5'), a stationary rail (6; 6'; 6") located between the drive wheels (5, 5') and fixed to the ground, means (20; 32) for making the drive wheels (5; 5') bear against the rail (6; 6'; 6") and means (19; 21; 25, 26, 27) for transmitting the power of the drive wheels (5; 5') to the unit.

Description: Device for propelling a trackbound unit This invention relates to a device for propelling a trackbound unit. At propelling of trackbound units, especially in the mining industry, locomotives are usually used which can be either diesel-driven or electrically driven. How¬ ever trains driven by such locomotives only manage descents of the order of 15-20 /oo. In open cut mines trucks usually are used which transport the mined ore along helically running ways. The trucks usually manage descents up to about 7 . As an alternative of transport with trains or trucks conveyor belts are also used which normally manage descents of about 15-17 . It is also known to propel trackbound train sets by the aid of drive stations placed along the rail, which apply a force to the cars longitudinally of the rail when they pass the drive stations. This propelling principle manages great descents. However, relative great costs are involved in building drive stations and other supplementary equipment. It is the object of this invention to provide a de¬ vice of the kind mentioned by way of introduction by means of which a trackbound unit can be propelled in very big descents of the order of 30°. This object of the invention is realized by means of a device being given the characteristic features de¬ fined in the appended claims. An illustrative example of the invention will be described below with reference to the enclosed drawings, where fig 1 shows a towing unit provided with a device according to the invention; fig 2 is an end view of the device according to the invention; fig 3 is a lateral view of the device according to the invention; fig 4 is a plan view of the shear mechanism included in the device of the invention; fig 5 is an end view of the guide wheel arrangement included in the device according to the invention; fig 6 is a schematic plan view of a further embodiment of the propulsion unit according to the invention; figs 7 and 8 are schematic lateral views of the propulsion unit according to fig 6; fig 9 shows a detail of the drive wheels of the propulsion unit; fig 10 is a lateral view of a detail of an embodiment of a joint of the central rail; and fig 11 is a plan view of the detail according to fig 10. The trackbound towing unit shown in fig 1 comprises a substructure 1, which is supported by wheels 2,3 in a bogie or single-axle embodiment. On the substructure 1 there is arranged a propulsion unit 4, which acts via drive wheels 5 on a stationary rail 6 mounted in the centre of the track. The propulsion unit 4 comprises in the illustrative example shown two hydraulic motors 7, which are served by a hydraulic unit 8 arranged on the substructure 1. The construction and function of the propulsion unit will be described in further detail with reference to figs 2-5. As is apparent from figs 2-4 the propulsion unit 4 is supported by a framework 9 of the substructure 1. The suspension is arranged by means of four links 10, which are articulatedly attached to the framework 9 at their lower ends, while the upper ends are articulatedly attached to a supporting frame 11 of the hydraulic mo¬ tors 7. The supporting frame 11 has four fulcrums 12 for the pin 13 of two axles 14, which support each their hydraulic motor 7. This means that the hydraulic motors 7 are rotatably suspended relative to the supporting frame 11, i e the hydraulic motors 7 with the drive wheels 5 can swing in towards the central rail 6. The drive wheels 5 are connected with the hydraulic motors 7 via spherically pivoted axles 15, which brings a certain possibility of movement between the drive wheels 5 and the hydraulic motors 7, e g for taking up irre¬ gularities or bends in the central rail 6. The towing unit also comprises a so-called shear mechanism 16 for the displacement of the towing unit relative to the central rail 6. The shear mechanism 16, which is best seen in figs 3 and 4, comprises two levers 17, which at their right ends in figs 3 and 4 are articulatedly connected to a connection piece 18 not being connected with the frame¬ work 9. The levers 17 are pivotably suspended on the axles 15 of the drive wheels 5, which means that the drive wheels 5 will be pressed against the central rail 6 when the levers 17 are swung towards one another. At the left ends of the levers 17 in figs 3 and 4 guidewheels 19 are rotatably mounted. The guide wheels 19 are interconnected by means of a spring box 20, which tends to press the guide wheels 19 towards each other, see fig 5. As is apparent from figs 3 and 5 a guide rail 21 is arranged between the guide wheels 19. This guide rail 21 is rigidly fixed to the framework 9 of the towing unit. In the framework 9 a clamp 21a is also anchored which surrounds the guide wheels 19. The shear mechanism 16 described is thus not connect¬ ed to the framework 9 but follows the limited movement of the supporting frame 11 relative to the framework 9 longitudinally of the towing unit, which movement is made possible by the suspension of the supporting frame 11 in the links 10. In this connection it should be pointed out that according to a preferred embodiment of the invention it is a question of steel roll against steel rail both when drive wheel/central rail and guide wheel/guide rail are concerned. However, this does not mean by any means that the invention is restricted to exactly this choice of material but it is also possible that e g the drive wheel consists of some reinforced rubber material. The towing unit described above operates in the following way. When the train set with the towing unit is to be set in motion - we assume that the direction of motion is to the left in figs 3 and 4 - the hydraulic motors 7 are started, the drive wheels being made to rotate in the direction of the arrow 22 in fig 4. The spring box 20 now presses the guide wheels 19 towards the guide rail 21 with a predetermined force, the drive wheels 5 also being brought to bear against the central rail 6 via the levers 17. When the drive wheels 5 are brought to engagement with the central rail 6 the whole supporting frame 11 and also the shear mecha¬ nism 16 will be moved to the left in fig 3 when the drive wheels 5 roll against the central rail 6. The guide wheels 19 will then be pressed against each other via the clamp 21a, the pressing force increasing due to the form of the clamp 21a the longer the supporting frame 11 is moved.to the left in fig 4. This also means that the drive wheels 5 are pressed via the arms 17 harder against the central rail 6 when the supporting frame 11 is moved to the left in fig 4. The contact pressure of the drive wheels against the central rail 6 is thus adjusted in dependence of the necessary propulsion force. Said transmission takes place by means of the shear mechanism 16 and the guide wheels 19 in the following way. When the drive wheels 5 bear against the central rail 6 with a certain pressure the guide wheels 19 are also press¬ ed via the levers 17 and the clamp 21a from both direc¬ tions against the guide rail 21 with a certain pressure, which is proportional to the contact pressure of the drive wheels 5 against the central rail 6. When the towing unit is moved to the left in figs 3 and 4 the shear mechanism 16, as described above, will move somewhat to the left in figs 3 and 4 in connection with the guide wheels 19 coming into contact with the guide rail 21. Thus, it can be said that the shear mecha¬ nism 16 and the shear wheels 19 are on their way to the left in figs 3 and 4 when the guide wheels 19 clamp the guide rail 21 from both directions. In this way the force applied to the guide rail 21 by each guide wheel 19 will be directed obliquely to the left in figs 3 and 4. By dividing this force into components a normal force is obtained perpendicularly to the guide rail 21 and a push¬ ing force in the longitudinal direction of the guide rail 21. The normal forces from the two σuide wheels 19 balance each other while the pushing forces cooperate. As the normal force of the guide wheels 19 against the guide rail 21 is proportional to the contact press¬ ure of the drive wheels 5 against the central rail, which pressure, in turn, according to the formula F = fjm x N, where F = the propulsion force, ,_,(. = the co¬ efficient of friction and N = the normal pressure is dependent on the propulsion force, i e the force the drive wheels 5 apply to the central rail 6 in its longitudinal direction, the normal pressure of the guide wheels 19 against the guide rail 21 will be dependent on the ne¬ cessary propulsion force applied to the central rail 6 by the drive wheels 5. This means that the greater force is required to displace the towing unit, the greater contact pressure is applied to the guide rail 21 by the guide wheels via the clamp 21a. This ensures that no sliding/rotation of the guide wheels 19 relative to the guide rail 21 takes place but the guide wheels 19 are locked in a position by the contact pressure. This fixa- tion of the guide wheels 19 relative to the guide rail 21 results in that the towing unit will be moved to the left in.ifigs 3 and 4 when the drive wheels 5 rotate in the direction of the arrow 22. Said displacement con¬ tinues as long as the drive wheels 5 are rotated in the direction of the arrow 22. It should be pointed out that the force exerted by the spring box 20 on the guide wheels 19 is only of importance in the initial phase to create the necessary engagement contact between the drive wheels 5 and the central rail 6. When a force transmitting engagement has been established between the drive wheels 5 and the central rail 6 the required contact pressure of the drive wheels 5 against the central rail 6 and the guide wheels 19 against the guide rail 21 is produced by the shear mechanism 16 in combination with the rotation of the drive wheels 5. After the starting phase the spring box 20 has the function, however, that it acts as a security bar or the like if the drive wheels 5 for some reason or other would lose their engagement with the central rail &. It has been described above how displacement of the towing unit to the left in figs 3 and 4 takes place. At displacement of the towing unit according to the invention to the right in figs 3 and 4 the drive wheels 5 are rotated via the hydraulic motors 7 in opposite direction, i e in the direction of the arrows 23. In a way corresponding to what has been described above the spring box 20 will press the levers 17 against each other, the drive wheels 5 rotating in the direction of the arrows 23. As soon as the drive wheels 5 get into con- tact with the central rail the whole supporting frame 11 is displaced to the right in figs 3 and 4, which dis¬ placement is taken up by the skew setting of the links 10. In a way corresponding to what has been described above this initial displacement results in that the contact pressure of the drive wheels 5 against the centr¬ al, rail becomes proportional to the necessary propulsion force and also that the contact pressure of the guide wheels 19 against the guide rail 21 will vary due to the shear mechanism 16 with the contact pressure of the drive wheels 5 against the central rail 6. Thus, the guide wheels 19 will in this case first move to the right in figs 3 and 4 before they clamp the guide rail 21 and transmit the propulsion force from the drive wheels to the framework 9. As is apparent from fig 3 the two links 10 located along one long side of the towing unit are not parallel to each other but diverge somewhat in upward direction in fig 3. The reason for this is that it is ensured that the drive wheels 5. start to"climb upwards" on the central rail 6 with a risk of the towing unit derailing as a consequence of this. If we assume again that the towing unit is to move to the left in fig 3 the supporting frame 11 will move to the left in fig 3 in the initial phase. The left end of the supporting frame 11 will then move somewhat while the right end is moving slightly upwards due to the geo¬ metry of the links 10. Thus, the drive wheels 5 will be inclined a little downwards in the direction of travel, which means that the front end of the towing unit, a_s seen in the direction of travel, is pressed downwards against the rail. As is apparent from fig 6 the propulsion unit 4 * also comprises in this embodiment two hydraulic motors 7', the suspension of the propulsion unit 4' however differing from that according to the illustrative example described above. The hydraulic motors 7' are connected with drive wheels 5 1 via axles 15', see fig 9. Also see figs 7 and 8. As is apparent from fig 9 the drive wheels 5' are mounted via spherical bearings 24, which means that the drive wheels 5' can always adjust themselves so that abutment against the central rail 6' throughout the en¬ tire cross section is obtained. Each hydraulic motor 7' with associated drive wheels 5' is adapted to a carrier 25 means, which in turn is pivotably suspended via an axle 26 in a holding means 27. The axle 26 is in the normal position in a vertical plane, the carrier means 25 thus being pivotable towards and from the central rail 6 ' . The holding means 27 is pivotable via a shaft 28 in a vertical plane. The axle 28 is supported by the framework 9' of the substructure of the towing unit. At both ends of the holding means 27 hydraulic cy- linders 29 are arranged, which are pivotably connected to the framework 9' with their one ends via axles 30 while the other ends of the hydraulic cylinders 29 are pivotably connected via axles 31 with the holding means 27 in the region of its upper end. By activation of the hydraulic cylinders 29 the holding means 27 can thus be swung in a vertical plane. The right ends of the carrier means 25 in figs 6-7 are reciprocally connected via a hydraulic cylinder 32, which can thus press the drive wheels 5' towards the central rail 6'. The embodiment of the propulsion unit 4' described above functions as follows. When the towing unit is to be moved in the direction of the arrow 33, see fig 7, the holding means 27 will be inclined in a vertical plane by activation from the hydraulic cylinders, the upper end of the holding means 27 being moved to the left in fig 7. The drive wheel 5' will be inclined downwards in the direction of the arrow 33, which means that the drive wheel 5* will tend to climb downwards on the centr- al rail 6' . Due to this arrangement the risk of the drive wheel 5' loosing its engagement with the central rail 6' will be eliminated in principle. In this connection it should be pointed out that the downwardly directed in¬ clination imparted to the drive wheel 5' is only of the order of 1 which, however, has been found to be quite enough. In the case when the towing unit is to be moved in opposite direction, see fig 8, i e in the direction of the arrow 34, the inclination of the drive wheel 5' is altered by shifting of the hydraulic cylinder 24 so that it is downwardly inclinded in the direction of travel. In a way corresponding to what has been mentioned above the drive wheel 5' will tend to climb downwards on the central rail 6'. Thus, there is no risk that the propul- sion unit 4* is lifted off the central rail. It is also possible within the scope of the inven¬ tion that the towing unit is provided with a hydraulic cylinder or the like at one of its ends, said cylinder being arranged between the bogie and the framework, the propulsion unit being rigidly mounted on the framework in this case. In order to provide the inclination of the drive wheel aimed at one end of the framework is raised and lowered, respectively, relative to the bogie by the aid of the hydraulic cylinder. The joint of a central rail 6" shown in figs 10 and 11 has an embodiment slightly different from the illust¬ rative examples described above. Thus, the central rail 6" has a constant thickness along its entire height. The fixation of the central rail 6" is carried out in such a way that two angle bars 36 are arranged on each sleeper 35 and placed in a spaced relationship to each other as seen in the longitudinal direction of the sleeper 35, said space corresponding to the thickness of the central rail 6", the central rail 6" being attached to the angle bars 36 preferably by welding. As is apparent from figs 10 and 11 the joint between two central rail .elements 6"a and 6"b is made so that said elements 6"a and 6"b have an inclined end surface 36a and 36b, respectively. The very joining of the elements 6"a and 6"b is carried out in such a way that the inclined end surfaces 36a and 36b, respectively, are placed at a little distance from each other, after which connection plates 37 are arranged by means of bolts 38 on both sides of the central rail 6". The embodiment of the joint described above is extra¬ ordinarily advantageous in respect of absorption of the forces applied to the central rail 6" by the drive wheels when propulsion of the trackbound vehicle is going on. By the inclined embodiment of the joint a successive trans- mission of the contact pressure from the drive wheels from one central rail element to the other takes place. Said embodiment of the joint also allows an arrangement of the end surfaces 36a and 36b, respectively, of the ele¬ ments 6"a, 6"b at some distance from each other without any "hack" arising at the passage of the drive wheels past the joint. Said distance is important because the elements 6"a and 6"b can be allowed thereby slightly to change their lengths as a consequence of e g temperature movements. The invention is by no means restricted to the illust¬ rative examples described above but can be freely varied within the scope of the appended claims.

Claims: Patent Claims 1. A device for propelling a trackbound unit, c h a r a c t e r i z e d by at least two drive wheels (5;5') swingable substantially perpendicularly to the direction of travel, means (7;7") for drive of the wheels (5;5') / a stationary rail (6;6*;6") located between the drive wheels (5;5*) and fixed to the ground, means (20;32) for making the drive wheels (5;5 f ) abut against the rail (6;6';6") and means (19,21 ;25,26,27) for transmitting the power of the drive wheels (5;5 ! ) to the trackbound unit. 2. The device of claim 1, c h a r a c t e r i z ¬ e d in that the means for making the drive wheels (5') abut against the central rail (6') consists of a press¬ ure medium cylinder (32) . 3. The device of claim 1 or 2, c h a r a c t e r ¬ i z e d in that it comprises means (27,28,29,30,31) for providing a certain inclination of the drive wheels (5') relative to the longitudinal direction of the central rail (6*). 4. The device of claim 3, c h a r a c t e r i z ¬ e d in that the drive wheels (5 1 ) are adapted at a carrier means (25) , which is swingable via a holding means (27) and a pressure medium cylinder (29) in a plane substantially parallel to the direction of travel of the trackbound unit. 5. The device of claim 1, c h a r a c t e r i z ¬ e d in that the drive wheels (5) and the drive means (4) are rotatably carried by a supporting frame (11), the swinging direction of the drive wheels and the drive means thus being substantially, perpendicular to the di¬ rection of travel, the supporting frame (11) being so supported relative to a framework (9) of the unit that the supporting frame (11) can be displaced relative to the framework (9) in the direction of travel of the unit, and that levers (17) are arranged on the axles (15) of the drive wheels (5) , which levers are swingable rela- - tive to the axles (15) in a plane substantially paral¬ lel to the plane on which the unit is resting, the one ends of the levers (17) being pivotably attached to a connection piece (18), and that rotatably mounted guide wheels (19) are arranged at the opposite ends of the levers (17), a guide rail (21) rigidly connected to the framework (9) being arranged between the guide wheels (19). 6. The device of claim 5, c h a r a c t e r i z e d in that the supporting frame (11) is supported by four links (10), which are articulatedly attached to the supporting frame (11) and to the framework (9) and that the links (10) oriented along the same long side of the unit diverge somewhat relative to one another in a di¬ rection from the support. 7. The device of any of claims 1, 5 or 6, c h a ¬ r a c t e r i z e d in that the means for making the drive wheels (5) abut against the rail (6) comprise a spring box (20) . 8. The device of any of the foregoing claims, c h a ¬ r a c t e r i z e d in that the elements (6"a,6"b) forming the central rail (6") have end surfaces (36a,36b) inclined relative to the longitudinal direction of the central rail (6") in the joining region of the elements (6"a, 6"b). 9. The device of claim 8, c h a r a c t e r i z e d in that the elements (6"a, 6"b) are joined by means of connection plates (37) arranged on both sides of the elements (6"a, 6"b) , said plates being anchored to the elements (6"a, 6"b) and placed in the region of the lower longitudinal edges of the elements (6"a, 6"b) .

Inventors: MAONSTROEM HILDING, MAONSTROEM, HILDING
Applicants: LUOSSAVAARA KIIRUNAVAARA AB, LUOSSAVAARA-KIIRUNAVAARA AKTIEBOLAG
Application year: 1985
Main classification: B61B13
IPC codes: B61B13, B61C11