A TORQUE-EQUALIZING DEVICE FOR GEAR MECHANISMS

Abstract: The invention refers to a torque-equalizing device for gear mechanisms, driven together and acting on the same object and preferably of the kind including two opposed plane crown wheels or so-called face gears for commonly driving a vehicle wheel or the like, and coupled together through a pair of mutually meshing pinions, one of which is connected with a driving motor mounted in the vehicle chassis or the like. For elimination tooth play in the meshing of the gears, the invention suggests that in the power train from the vehicle chassis to the pair of face gears are mounted equalizing means (21; 30; 26, 27, 28) allowing a limited relative angular movement between some of the members of said power train.

Description: A torque-equalizing device for gear mechanisms The present invention refers to a torque-equalizing device for gear mechanisms, driven together and acting on the same ob- ]ect and preferably of the kind including two opposed plane crown wheels or so-called face gears for commonly driving a vehicle wheel or the like, and coupled together through a pair of mutually meshing pinions, one of which s connected with a driving motor mounted in the vehicle chassis or the like. Gear mechanisms of the aforementioned kind recently have been developed and in many cases in connection therewith the tooth-play in the meshing between the wheels and pinions needs to be eliminated. The present invention has for an object to eliminate such tooth-play, particularly in connection with gear mechanisms disclosed in WO 95/16151 although the inventive device well might be used in other constructions for filling similar purposes . The present invention is distinguished substantially in that m the power train from the vehicle chassis to the pair of face gears are mounted equalizing means allowing a limited relative angular movement between some of the members of said power train. By way of example the invention will be further described below with reference to the accompanying drawings in which Fig. 1 is a diametrical section through the inventive device as applied to a gear device in which a vehicle wheel, illustrated only by a wheel rim, is driven by means of two face gears meshing through a pair of pinions, one of which is driven from a non-illustrated motor, Fig. 2 is a sectioned detail view of the arrangement according to Fig. 1, Fig. 3 is another cross sectional view of a vehicle wheel drive device similar to Fig. 1, in wnich however the driving motor is mounted angularly movable around ts longitudinal axis, while Fig. 4 illustrates another embodiment of the inventive device, Fig. 4a being a detail view of the arrangement in Fig. 4 and Fig. 4b another detail view similar to Fig. 4a but of still another embodiment of the inventive device. In the drawing is illustrated the present invention as applied to the drive tram of a vehicle wheel having a wheel rim 1 which is secured to a wheel hub 2. Said hub 2 is rotably jour- nalled through suitable roller bearings on a casing 3 Within said hub 2 is housed a pair of crown wheels 2a, 2b of a known gear device and being of plane type, i.e. face gears. The casing 3 extends axially through the central portions of said pair of crown wheels 2a, 2b and of the hub 2. In its turn the casing 3 houses a drive motor 4. Through said casing 3 and by suitable bolt connections 5 the motor 4 is carried by a portion 6 of the lower part or chassis of a vehicle not further illustrated. The drive motor 4 in the present case is thought to be a hydraulic motor and therefore comprises suitable hydraulic connections 7, 8 to a hydraulic system within the vehicle comprising a hydraulic pump. However, the motor 4 also might be an electric motor of suitable kind having corresponding electric connections 7 and 8 to a generator or an accumulator in the vehicle . At its free end the output shaft 9 of the driving motor 4 is provided with a gear or pinion 10 which in this case is constituted by a cylindrical gear adapted to co-operate with the face gear 2a. The shaft 9 thereby lies on a line which s parallel to a radius of the face gear 2a and at a suitable spacing from the toothed surface of the face gear in order to mesh with the teeth thereof . The second face or crown wheel 2b is mounted -coaxially with and opposed to said first crown wheel or face gear 2a and meshes with the first pinion 10 through an intermediary second pinion 11 which, of course, also is a cylindrical gear in the present case and mounted on an axis which is parallel to the shaft 9 and is freely rotatably journalled in the casing 3. Owing to the fact that the second crown wheel 2b is driven under the intermediation of the intermediary pinion 11 from the first pinion 10 the two crown wheels 2a, 2b will rotate in the same direction contrary to prior constructions. This implies improved driving conditions to the two pinions 10 and 11, which increase their service life. The meshing of the pinions 10, 11 and crown wheels 2a, 2b also will be improved. As well known, a correct co-operation in the tooth meshing between crown wheels 2a, 2b and the respective pinion 10, 11 requires a slight play in the meshings which in the present case might cause an overload of one of the crown wheels when taking up all drive power alone. Therefore, the present invention sug- gests that in the power train from the vehicle chassis to the pair of face gears 2a, 2b are mounted equalizing means which allow a limited relative angular movement between some of the members of said power train. In accordance with the invention said equalizing means may take various forms such as will be de- scribed in detail in the following. Thus in Fig. 1 it is illustrated a first embodiment of the invention, according to which the equalizing means comprise a number of link pins 21 oriented at right angles to the planes of the face gears 2a, 2b, and equally circu ferentially spaced and at each end loosely seated in bores 22 in the respective face gear. The number of pins is at least two but preferably three or more. The loose fit of the pins in the bores 22 is to be selected such that the necessary mutual angular movement between the two face gears 2a, 2b will be allowed. Furthermore, in its central portion the respective link pin 21 is to pass with a suitable play through a corresponding hole 23 in a radially inwardly directed flange 24, formed interiorly of the hub 2. As can be seen from Fig. 2 said hole 23 might be made progressively widening towards its ends so as not to interfere with the necessary pivoting motion of the link pin 21 during the mutual angular adjustment movements of said face gears 2a, 2b. For obtaining a smoother operation of the inventive device, the link pins 21 can be dimensioned to their diameter and selected to their material characteristics such that they will have a slight resilient action. In Fig. 4 and 4a is illustrated another embodiment of the invention in which at the periphery of at least one of the face gears, 2b, is formed a recess 25, in which is accomodated a pair of tangentially mounted pressure springs 26 between which is inserted a lug 27 supported from the respective other face gear 2a via a carrying member 28 such as an axial flange in order to allow a limited resilient relative angular movement between said face gears 2a, 2b. In Fig. 4b is illustrated a similar embodiment in which both face gears 2a, 2b are provided with such a peripheral recess 25 in which a lug 27 supported from the respective other face gear is accomodated. It is to be noted, however, that in Fig. 4b the two recesses 25 have been illustrated as being located directly opposite each other just for the sake of clarity while in practice they are to be located diametrically opposite each other. The inventive torque-equalizing action also can be obtained by suspending the motor itself from the vehicle chassis or the like by means of support means 30 which provide for a limited angular movement of said motor 4 relative said chassis around the axis X-X of the motor 9 such as illustrated in Fig. 3.

Claims: C l a i s 1. A torque-equalizing device for gear mechanisms, driven together and acting on the same object and preferably of the kind including two opposed plane crown wheels or so-called face gears for commonly driving a vehicle wheel or the like, and coupled together through a pair of mutually meshing pinions, one of which is connected with a driving motor mounted in the vehicle chassis or the like, c h a r a c t e r i z e d i n that in the power train from the vehicle chassis to the pair of face gears are mounted equalizing means (21; 30; 26, 27, 28) allowing a limited relative angular movement between some of the members of said power train. 2. A device according to claim 1, c h a r a c t e r i z e d i n that said equalizing means comprise at least two circumfer- entially equally spaced link pins (21) at right angles to the planes of the face gears and at either end loosely seated in the respective face gear, the respective link pin at its centre portion passing with play through a corresponding hole (23) in a radially inwardly directed flange (24) formed interiorly of a wheel hub (2) . 3. A device according to claim 1, c h a r a c t e r i z e d i n that at the periphery of at least one of the face gears (2b) is formed a recess (25) , in which is accomodated a pair of pres- sure springs (26) , between which is inserted a lug (27) supported from the respective other face gear (2a) via a carrying member (28) such as an axial flange, in order to allow a limited resilient relative angular movement between said face gears (2a, 2b) . 4. A device according to claim 1, c h a r a c t e r i z e d i n that the motor (4) is suspended from the vehicle chassis or the like by means of support means (30) which provide for a lim- ited angular movement of said motor (4) relative said chassis around the axis (X-X) of the motor (4) .

Inventors: BRATT STIG, HYDREN INGVAR, BRATT, STIG, HYDREN, INGVAR
Applicants: BRATT STIG, HYDREN INGVAR, PARKER HANNIFIN AB, BRATT, STIG, HYDREN, INGVAR
Application year: 1996
Main classification: F16H1
IPC codes: B60K7, B60K17, F16H1