DE102009031794A1 - Drive arrangement for a continuously variable transmission of a motor vehicle - Google Patents

Abstract

The invention relates to a drive arrangement for a continuously variable transmission, in particular a crank CVT of a motor vehicle, with a drive shaft, at the end regions of outer bearings for rotatably supporting the drive shaft with respect to a transmission housing are arranged, wherein the drive shaft has a recess in the an adjusting shaft is rotatably arranged, in whose rotation eccentric components of an arranged on the drive shaft eccentric are continuously adjustable. The drive shaft has in its region between the outer bearings at least one rotatably connected to it, cylindrical bearing disc on the outer surface of another bearing for supporting the drive axle is arranged with respect to the transmission housing.

Description

The The present invention relates to a drive arrangement for a continuously variable transmission, in particular for a crank CVT of a motor vehicle.

From the DE 102 43 535 A1 is a continuously variable transmission of a motor vehicle, which essentially comprises a drive shaft and an output shaft, which are mounted parallel to each other rotatably mounted in a transmission housing. In this case, these two shafts are connected to one another via an eccentric device provided on the drive shaft and a freewheel device arranged on the output shaft. The eccentric consists of a plurality of eccentric units, which are arranged axially next to one another on the drive shaft. The freewheel device consists of several freewheel units, which are arranged axially adjacent to one another on the drive shaft.

to Formation of each eccentric unit faces the drive shaft its axis of rotation eccentrically offset guide area on, on the lateral surface of an eccentric rotatable is stored. On the Exzenterbauteil is in the embodiment continuously variable transmission as a crank CVT (Continuous Variable Transmission) one side of at least one connecting rod rotatably mounted.

each Eccentric component has a recess for receiving a guide portion the drive shaft, wherein around the recess an internal toothing runs. The internal toothing is on the lateral surface of the guide area tuned such that the eccentric over the internal toothing is centered on the guide area.

The Drive shaft or the guide portions of the same have one in the direction of the axis of rotation of the drive shaft extending recess in which an adjusting rotatable is arranged. The adjusting shaft has an outer toothing, which engages in the internal toothing of the eccentric components. The adjusting shaft is about the top circle of the external teeth forming portions of the external toothing in the recess stored the driving shaft. The management areas are formed so crescent-shaped that their recesses on a certain angular range are open, so that in these angular ranges the outer toothing of the adjusting against the outer man telfläche the guide areas can protrude radially, with an engagement in the internal toothing the eccentric component is made possible.

The have disc-shaped guide areas in Reference to its cylindrical surface a center line, at a certain distance from the axis of rotation the drive shaft is arranged eccentrically. The eccentric components have in relation to their cylindrical lateral surfaces one Midline, which is opposite to the midline of the Guide areas eccentrically offset by a distance so is that the eccentricity of the center line of the eccentric components double compared with the axis of rotation of the drive shaft is as big as the eccentricity of the midline the guide areas relative to this axis of rotation.

By the rotation of the adjusting shaft in the recess of the drive shaft becomes the eccentric component of an eccentric unit about the centerline twisted the corresponding leadership area. It wanders the center line of the eccentric component about the center line of the guidance area, wherein the extent of eccentricity of the Exzenterbauteiles changed with respect to the axis of rotation of the driving shaft becomes.

The Adjustment is common in the known continuously variable crank CVT's inserted without storage and with little play in the drive shaft. One The problem is that the flexurally soft drive shaft supported under load on the adjusting shaft, wherein an increased Adjustment torque is created, which is due to a metallic friction during clamping the adjusting shaft in the axial recess of the driving shaft is due. Because the adjusting moment thereby is increased, this leads to an increased Electricity demand on the side of the adjusting shaft when adjusting rotating electric drive.

A Bending the flexible drive shaft can according to a Patent application of the same date of the present patent applicant thereby be minimized that at the outside with their Side mounted in a transmission housing drive shaft axially spaced, cylindrical stiffening areas axially spaced apart between the outer Bearing locations of the drive axle can be provided, wherein the cylindrical Inner surfaces of these middle stiffening areas on rolling bodies support, which are arranged in circumferential grooves of the adjusting are. As a result, the friction between the adjusting and the drive shaft can be reduced.

The The object of the present invention is a drive arrangement for a continuously variable transmission of a motor vehicle to design such that a deflection of the drive shaft can be largely reduced or avoided.

This task is accomplished by a drive solved order for a continuously variable transmission, in particular a crank CVT of a motor vehicle having a drive shaft, at the end portions of outer bearings for rotatably supporting the drive shaft are arranged in a transmission housing. The drive shaft has a recess in which an adjusting shaft is rotatably arranged, in the rotation of the Exzenterbauteile an arranged on the drive shaft eccentric are continuously adjustable. The drive shaft has in its region between the outer bearings at least one rotatably connected to it, cylindrical bearing disc, on the outer surface of another bearing for supporting the drive axle is arranged in the transmission housing.

Of the significant advantage of the drive assembly according to the invention is that one with regard to the claimed space and the weight cheap, strength and stiffness-optimized Storage of the drive shaft by the provision of another middle Bearing point, in addition to the outer Storage locations, is possible. On both sides of the bearing disc, preferably centrally between the outer bearings is arranged, the drive axle one, but preferably several in the direction of its axis of rotation spaced apart stiffening areas advantageously, to increase the flexural rigidity contribute to the drive shaft.

at an advantageous embodiment of the invention, the drive shaft to achieve a particularly effective storage in their area between the outer bearings several, each rotatably with their bonded, cylindrical bearing washers facing towards the axis of rotation of the drive shaft are spaced from each other.

The Drive shaft of the drive assembly can in the direction of its axis of rotation have a plurality of mutually spaced stiffening regions, wherein at least one stiffening area serves as a bearing disk.

The Drive shaft of the present drive assembly may be part of a Crank CVT's be, with the rotation of the drive shaft over a arranged on the drive shaft eccentric and connecting rods to a freewheel device in the transmission housing transmitted pa rallel to the drive shaft mounted output shaft becomes. The eccentric comprises on the drive shaft in axial Direction spaced apart eccentric components, which on the Drive shaft either between the bearing disc and the outer Bearings or on the drive shaft between bearing washers and / or between an outer bearing and an adjacent one Bearing disc or on the drive shaft between stiffening areas, and / or between a stiffening area and a bearing disc and / or between an outer bearing and a adjacent stiffening area are arranged.

in the Below, the invention and its embodiments are related explained in more detail with the figures. Show it:

1 a longitudinal section of a drive shaft of the drive assembly according to the invention and

2 a perspective view of the arrangement of 1 ,

To The invention led to the following considerations. A bending-free, space-saving and lightweight Arrangement of the drive shaft in a transmission housing can be achieved by that of the usual structure the drive shaft with the directly adjacent eccentric components departed and in addition to the outer Bearings in which the outer sides of the Drive shaft mounted with respect to the transmission housing are at least one more depository in the middle area of the Drive shaft for their additional storage or support is provided with respect to the transmission housing.

In the 1 , is the drive shaft of a continuously variable transmission with 1 designated. In an axial recess of the drive shaft 1 an adjustment shaft (not shown) is arranged in a conventional manner. The outer end portions of the drive shaft 1 are in a gearbox 4 with the help of warehouses 6 and 7 rotatably mounted, as shown schematically.

The drive shaft 1 preferably has the stiffening areas already mentioned above 3 on, in the axial direction of the drive shaft 1 spaced apart between the bearings 6 and 7 are arranged and to increase the rigidity of the drive shaft 1 contribute. The stiffening areas 3 each have the shape of cylindrical circular discs concentric with the axis of rotation 8th the drive shaft 1 are arranged. It is pointed out that stiffening areas 3 can be provided in different numbers. Also, an embodiment of the invention without stiffening areas 3 conceivable.

In the manner shown is according to the invention in the area between the camps 6 and 7 , preferably in the middle of a bearing disc 5 non-rotatable with the drive axle 1 connected or formed, for additional storage of the drive axle 1 with respect to the gearbox 4 serves. The bearing disc 5 has the shape of a cylindrical disc concentric with the axis of rotation 8th the drive shaft 1 are arranged. On the outer surface of the bearing disc 5 is the schematically illustrated bearing 9 arranged. It should be noted that also several bearing washers 5 for additional support in the area between the bearings 6 and 7 can be provided. It is also conceivable according to an embodiment of the invention, the cylindrical outer surfaces of the stiffening areas 3 to use additional bearings for the formation.

The eccentric components connected with connecting rods 2 can in the apparent manner between the bearing disc 5 , the stiffening areas 3 and the camps 6 . 7 be arranged.

1

drive shaft

2

eccentric

3

stiffening region

4

gearbox

5

bearing disk

6

camp

7

camp

8th

axis of rotation

9

camp

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 10243535 A1 [0002]

Claims (7)

Drive arrangement for a continuously variable transmission, in particular a crank CVT of a motor vehicle, having a drive shaft ( 1 ), at their end outer bearings ( 6 . 7 ) for rotatably supporting the drive shaft ( 1 ) with respect to a transmission housing ( 4 ) are arranged, wherein the drive shaft ( 1 ) has a recess in which an adjusting shaft is rotatably arranged, in whose rotation eccentric components ( 2 ) one on the drive shaft ( 1 ) arranged eccentric are continuously adjustable, characterized in that the drive shaft ( 1 ) in their area between the outer camps ( 6 . 7 ) at least one, non-rotatably connected to it, cylindrical bearing disc ( 5 ), on whose outer surface another bearing ( 9 ) for the storage of the drive axle ( 1 ) with respect to the transmission housing ( 4 ) is arranged. Drive arrangement according to claim 1, characterized in that the drive shaft ( 1 ) in their area between the outer camps ( 6 . 7 ), in each case non-rotatably connected to it, cylindrical bearing discs ( 5 ), which in the direction of the axis of rotation ( 8th ) of the drive shaft ( 1 ) are spaced from each other. Drive arrangement according to claim 1 or 2, characterized in that the drive axle ( 1 ) a plurality of spaced apart in the direction of its axis of rotation, on both sides of the bearing disc ( 5 ) arranged stiffening areas ( 3 ) having. Drive arrangement according to claim 1 or 2, characterized in that the drive axle ( 1 ) a plurality of spaced in the direction of its axis of rotation stiffening regions ( 3 ), wherein at least one stiffening region ( 3 ) as a bearing disk ( 5 ) serves. Drive arrangement according to one of claims 1 to 5, characterized in that the drive shaft ( 1 ) Is part of a crank CVT, wherein the rotation of the drive shaft ( 1 ) via one on the drive shaft ( 1 ) arranged eccentric and connecting rods on a freewheel device one in the transmission housing ( 4 ) parallel to the drive shaft ( 1 ) is transmitted, wherein the eccentric on the drive shaft ( 1 ) spaced apart in the axial direction eccentric components ( 2 ) located on the drive shaft ( 1 ) between the bearing disc ( 5 ) and the outer camps ( 6 . 7 ) are arranged. Drive arrangement according to one of claims 2 to 5, characterized in that the drive shaft ( 1 ) Is part of a crank CVT, wherein the rotation of the drive shaft ( 1 ) via one on the drive shaft ( 1 ) arranged eccentric and connecting rods on a freewheel device one in the transmission housing ( 4 ) parallel to the drive shaft ( 1 ) is transmitted, wherein the eccentric on the drive shaft ( 1 ) spaced apart in the axial direction eccentric components ( 2 ) located on the drive shaft ( 1 ) between the bearing discs ( 5 ) and between one bearing disc ( 5 ) and the adjacent outer bearing ( 6 . 7 ) are arranged. Drive arrangement according to claim 3, characterized in that the drive shaft ( 1 ) Is part of a crank CVT, wherein the rotation of the drive shaft ( 1 ) via one on the drive shaft ( 1 ) arranged eccentric and connecting rods on a freewheel device one in the transmission housing ( 4 ) parallel to the drive shaft ( 1 ) is transmitted, wherein the eccentric on the drive shaft ( 1 ) spaced apart in the axial direction eccentric components ( 2 ) between the stiffening areas ( 3 ), between the bearing disc ( 5 ) and in each case an adjacent stiffening area ( 3 ) and between each outer bearing ( 6 . 7 ) and an adjacent stiffening area ( 3 ) are arranged.