Transmission arrangement for a motor vehicle

Abstract

A transmission arrangement for a motor vehicle, having a transmission housing, a first pinion shaft, and a second pinion shaft, which is arranged coaxially to the first pinion shaft, and having a first transmission output shaft and a second transmission output shaft. The first pinion shaft is mounted by a first bearing, and the second pinion shaft is mounted by a second bearing, on the transmission housing, and a first pinion meshing with a first crown gear arranged on the first transmission output shaft is arranged in a rotationally fixed manner on the first pinion shaft, and a second pinion meshing with a second crown gear arranged on the second transmission output shaft is arranged in a rotationally fixed manner on the second pinion shaft.

Claims

1. A transmission arrangement for a motor vehicle, comprising: a transmission housing, a first pinion shaft, and a second pinion shaft, which is arranged coaxially relative to the first pinion shaft, and having a first transmission output shaft and a second transmission output shaft, wherein the first pinion shaft is mounted by a first bearing, and the second pinion shaft is mounted by a second bearing, on the transmission housing, and wherein a first pinion meshing with a first crown gear arranged on the first transmission output shaft is arranged on the first pinion shaft in a rotationally fixed manner, and a second pinion meshing with a second crown gear arranged on the second transmission output shaft is arranged on the second pinion shaft in a rotationally fixed manner, wherein the first bearing or the second bearing is connected to the transmission housing by a temperature expansion compensation element and can be displaced in the axial direction with respect to an axis of rotation of the pinion shaft by the temperature expansion compensation element, wherein the two pinion shafts are mounted together by at least one spring-loaded axial bearing, or the two pinion shafts are mounted together by a plurality of axial bearings and at least one of the axial bearings is spring-loaded, wherein a spring element effecting the spring loading forces the first pinion and the second pinion apart from each other.

2. The transmission arrangement according to claim 1, wherein the temperature expansion compensation element is associated with the first bearing, and another temperature expansion compensation element is associated with the second bearing.

3. The transmission arrangement according to claim 2, wherein the temperature expansion compensation element is arranged on the side of the first bearing that faces away from the first pinion, and/or the other temperature expansion compensation element is arranged on the side of the second bearing that faces away from the second pinion.

4. The transmission arrangement according to claim 1, wherein the first bearing is biased in the direction of the temperature expansion compensation element.

5. The transmission arrangement according to claim 1, wherein the first bearing and the second bearing form a support bearing, or form a fixed/floating bearing, and/or the second bearing is spring-loaded in the direction of the second pinion or in the direction facing away from the second pinion.

6. The transmission arrangement according to claim 1, wherein the two pinion shafts are mounted together by means of a second axial bearing, wherein one of the pinion shafts is connected rigidly to the first axial bearing in the axial direction, and the other pinion shaft is connected to the second axial bearing in the axial direction by way of a temperature expansion compensation sleeve or is supported against it.

7. The transmission arrangement according to claim 6, wherein the temperature expansion compensation element has a larger thermal expansion coefficient than the transmission housing, and/or the temperature expansion compensation sleeve has a thermal expansion coefficient differing from that of the transmission housing.

8. The transmission arrangement according to claim 1, wherein the spring element effecting the spring loading is partially compressed at a design limit temperature.

9. The transmission arrangement according to claim 1, wherein: the two transmission output shafts are aligned with each other or are arranged axially parallel at a distance from one another.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention will be explained in detail on the basis of the exemplary embodiments illustrated in the drawing, without any limitation of the invention thereby occurring. Shown herein are:

(2) FIG. 1 a first embodiment of a transmission arrangement for a motor vehicle;

(3) FIG. 2 a second embodiment of the transmission arrangement in two different variants; and

(4) FIG. 3 a third embodiment of the transmission arrangement, once again in two different variants.

DETAILED DESCRIPTION

(5) FIG. 1 shows a first embodiment of a transmission device 1 for a motor vehicle. The transmission arrangement 1 has a transmission housing 2, which is only hinted at here. The transmission device 1 is further equipped with a first pinion shaft 3 and a second pinion shaft 4, which is coaxially arranged in it. The first pinion shaft 3 is connected to a first pinion 5 and the second pinion shaft 4 is connected to a second pinion 6 or is designed in one piece therewith. The first pinion 5 meshes with a first crown gear 7, which is connected to a first transmission output shaft 8. The first crown gear 7 and the first transmission output shaft 8 are mounted so as to be able to rotate around an axis of rotation 9. In contrast, the second pinion 6 meshes with a second crown gear 10, which is connected to a second transmission output shaft 11.

(6) The second crown gear 10 and the second transmission output shaft 11 are mounted so as to be able to rotate around an axis of rotation 12. On account of their coaxial arrangement, the two pinion shafts 3 and 4 and consequently the two pinions 5 and 6 are mounted so as to be able to rotate around a common axis of rotation 13. The bearing of the first pinion shaft 3 is provided by means of a first bearing 14 and that of the second pinion shaft 4 is provided by means of a second bearing 15. The pinion shafts 3 and 4 are mounted on the transmission housing 2 by way of the bearings 14 and 15.

(7) The transmission housing 2 has a thermal expansion coefficient that differs from the thermal expansion coefficient of the first pinion shaft 3 and/or of the second pinion shaft 4. Accordingly, measures for temperature compensation or for compensation of different temperatures or thermal expansions of the transmission housing 2 and of the pinion shafts 3 and 4 are necessary. For this reason, the first bearing 14 is connected via a temperature expansion compensation element 16, and the second bearing 15 is connected via another temperature expansion compensation element 17, to the transmission housing 2. In particular, the bearings 14 and 15 are each supported in the axial direction against the transmission housing 2 by way of the respective temperature expansion compensation element 16 or 17. Accordingly, the bearings 14 and 15 can be displaced in the axial direction with respect to the axis of rotation 13 by the temperature expansion compensation elements 16 and 17.

(8) However, because the temperature compensation can be adjusted precisely only to a single temperature by means of the temperature expansion compensation elements 16 and 17, it is provided that the two pinion shafts 3 and 4 are mounted to each other by means of a plurality of axial bearings—in the exemplary embodiment illustrated here, there are two axial bearings 18 and 19. The axial bearings 18 and 19 limit a displacement of the pinion shafts 3 and 4 with respect to each other in the axial direction in respectively opposite directions. In this case, the axial bearing 19 is spring-loaded by means of a spring element 20. The spring element 20 is preferably a disc spring. It rests against the second pinion shaft 4 and engages on its side facing away from the pinion shaft 4 at the axial bearing 19, which, on its part, is supported on the first pinion shaft 3 in the axial direction.

(9) In this regard, the spring element 20 effects a spring force in the axial direction, which presses apart the two pinions 5 and 6, so that the two bearings 14 and 15 are biased outward in the axial direction. In particular, the spring element 20 is designed such that the pinion shafts 3 and 4 are displaced in the axial direction so that, in the axial direction, the axial bearing 18 rests, on the one hand, against the pinion shaft 3 and, on the other hand, against the pinion shaft 4.

(10) In this regard, the spring element 20 counteracts a displacement of the bearings 14 and 15 by the temperature expansion compensation elements 16 and 17 or effects a restoration of the bearings 14 and 15 in the case of decreasing dimensions of the temperature expansion compensation elements 16 and 17 in the axial direction. Preferably, it is provided that the axial bearings 18 and 19 are arranged on different sides of the first pinion 5—as viewed in the axial direction.

(11) It can be seen that the pinions 5 and 6 have the same diameter. The same is true also for the crown gears 7 and 10. However, this makes it necessary for the axes of rotation 9 and 12 of the crown gears 7 and 10 or of the transmission output shafts 8 and 11 to be arranged at an offset, namely, spaced apart from each other in the axial direction with respect to the axis of rotation 13. In this regard, the axes of rotation 9 and 12 are spaced parallel to each other. Preferably, in addition, the axes of rotation 9 and 12 are situated perpendicularly on an imaginary plane that incorporates in it the axis of rotation 13. It can also be provided that the axes of rotation 9 and 12 are each situated perpendicular to the axis of rotation 13.

(12) FIG. 2 shows a second embodiment of the transmission device 1 in two different variants, wherein a first of the variants is illustrated above the axis of rotation 13 and a second of the variants is illustrated below the axis of rotation 13. Reference is basically made to the preceding statements relating to the first embodiment and the differences will be addressed below. Said differences lie essentially in the fact that the temperature expansion compensation element 16, but not the temperature expansion compensation element 17, is provided. The function of the temperature expansion compensation element 17 is assumed in the scope of the second embodiment by a temperature expansion compensation sleeve 21.

(13) For the first variant, said temperature expansion compensation sleeve is present in the axial direction between the axial bearing 18 and the first pinion shaft 3, particularly between the axial bearing 18 and the first pinion 5. This means that the temperature expansion compensation sleeve 21 is supported, on the one hand, at the first pinion shaft 3 or the first pinion 5, and, on the other hand, at the axial bearing 18, which, in turn, rests against the second pinion shaft 4 on its side facing away from the temperature expansion compensation sleeve 21, as viewed in the axial direction, or is supported against it. The temperature expansion compensation sleeve 21 preferably has a thermal expansion coefficient that differs from that of the transmission housing 2, in particular a higher thermal expansion coefficient. The axial bearing 19 is spring-loaded, in turn, by means of the spring element 20, so that it presses the first pinion shaft 3 or the first pinion 5 against the axial bearing 18, and the latter, in turn, as viewed in the axial direction, against the second pinion shaft 4.

(14) Furthermore, it is provided that the second bearing 15 is spring-loaded by means of a spring element 22, which, in turn, can be designed as a disc spring. In this case, the spring loading on the second bearing 15 is preferably directed in the axial direction toward the first bearing 14. The spring element 22 is designed such that, when a design limit temperature is reached, a full compression of the spring element 22 does not occur, but instead only a partial compression occurs. The spring element 22 has, for example, a remaining spring path limitation, in particular by a configuration with a blocking sleeve.

(15) The second variant of the second embodiment differs from the first variant only in that, as viewed in the axial direction, the temperature expansion compensation sleeve 21 is now present between the first pinion shaft 3 or the first pinion 5 and the axial bearing 19, which, on its side facing away from the temperature expansion compensation sleeve 21, is supported against the second pinion shaft 4 in the axial direction. Furthermore, the spring element 20 is then associated with the axial bearing 18, so that the latter is therefore spring-loaded. Otherwise, reference is made to the configurations relative to the first variant of the second embodiment.

(16) FIG. 3 shows a third embodiment of the transmission device 1, once again in two variants. A first of the variants is illustrated above the axis of rotation 13, and a second below the axis of rotation 13. In regard to the third embodiment, reference is made to the statements in regard to the second embodiment and said statements are included here in full. Only the differences will be addressed below. Apart from the differences that are yet to be explained, the first variant of the third embodiment corresponds to the first variant of the second embodiment, and the second variant of the third embodiment corresponds to the second variant of the second embodiment.

(17) The differences from the second embodiment of the transmission device 1 lie in the fact that the first bearing 14 is designed as a fixed bearing and the second bearing 15 is designed as a floating bearing. In this case, both bearings 14 and 15 are designed such that they can absorb the axial forces in both directions. The bearings 14 and 15 can fundamentally be arranged so as to be displaced in the axial direction in the transmission housing 2. The first bearing 14 is present as a fixed bearing, because it is rigidly clamped between the temperature expansion compensation element 16 and a spring element 23, so that it can be displaced in the axial direction exclusively based on temperature-induced changes in the dimensions of the transmission housing 2 and/or of the temperature expansion compensation element 16. On its side facing away from first bearing 14 in the axial direction, the spring element 23 is supported against the transmission housing 2, for example, via a supporting element 24, in particular a securing ring or snap ring.

(18) The second bearing 15 is basically designed as a floating bearing. It is subjected to spring force in the axial direction by the spring element 22, with the spring force pressing the second bearing 15 in the axial direction away from the first bearing 14. However, the spring element 22 has only a small biasing. The first bearing 14 and the second bearing 15 together form a fixed/floating bearing for the pinion shafts 3 and 4.

(19) The above-described transmission device 1 makes possible an especially reliable compensation of temperature-induced stresses. In particular, it can be flexibly designed; for example, it enables a flexible selection of the bearing configuration. Thus, the first bearing 14 and the second bearing 15 can be designed as support bearings, as is illustrated on the basis of the first and second embodiment, for example. However, it is also possible to provide a fixed/floating bearing in accordance with the third embodiment.