RACK-AND-PINION GEAR FOR A MOTOR VEHICLE

Abstract

The disclosure concerns a rack-and-pinion gear for a motor vehicle. The rack-and-pinion gear includes a pinion shaft and a toothed rack, which are mounted inside a housing. In order to provide a rack-and-pinion gear with precise engagement, which can be produced economically, according to the disclosure it is provided that a position of the pinion shaft in the housing can be adjusted by at least one adjustment element so that a tilt of the pinion shaft relative to the toothed rack can be set.

Claims

1. A rack-and-pinion gear for a motor vehicle, comprising: a pinion shaft; and a toothed rack mounted inside a housing, wherein a position of the pinion shaft in the housing is adjusted by at least one adjustment element so that a tilt of the pinion shaft relative to the toothed rack is set.

2. The rack-and-pinion gear as claimed in claim 1, wherein the tilt of the pinion shaft is set inside a plane parallel to a running direction of the toothed rack.

3. The rack-and-pinion gear as claimed in claim 1, wherein the pinion shaft is mounted inside the housing via an end-side first bearing and a second bearing opposite the first bearing relative to the toothed rack, wherein the at least one adjustment element is assigned to the first or second bearing.

4. The rack-and-pinion gear as claimed in claim 3, wherein the at least one adjustment element is assigned to the first bearing.

5. The rack-and-pinion gear as claimed in claim 3, wherein precisely one of the first or second bearings is adjusted by the adjustment element such that a position of the pinion shaft inside the one of the first or second bearings is changed transversely to a running direction of the first or second bearing.

6. The rack-and-pinion gear as claimed in claim 1, wherein the adjustment element is a bearing bushing that indirectly mounts the pinion shaft, wherein the bearing bushing is formed eccentrically and has various angular positions around the shaft inside the housing.

7. The rack-and-pinion gear as claimed in claim 6, wherein the angular positions of the bearing bushing are arbitrary.

8. The rack-and-pinion gear as claimed in claim 6, wherein the bearing bushing is locked in an angular position inside the housing.

9. The rack-and-pinion gear as claimed in claim 1, wherein the adjustment element is assigned to a bearing that is linearly adjustable inside the housing.

10. The rack-and-pinion gear as claimed in claim 9, wherein the bearing is adjustable parallel to a running direction of the toothed rack.

11. A vehicle comprising: a steering gear including a pinion shaft with a pinion that cooperates with a tooth of a toothed rack mounted inside a housing; and a bearing bushing formed eccentrically with various angular positions around the pinion shaft inside the housing that adjusts a position of the pinion shaft in the housing such that a tilt of the pinion shaft relative to the toothed rack is adjustable inside the housing.

12. The vehicle as claimed in claim 11, wherein the tilt of the pinion shaft is set inside a plane parallel to a running direction of the toothed rack.

13. The vehicle as claimed in claim 11, wherein the pinion shaft is mounted inside the housing via an end-side first bearing and a second bearing opposite the first bearing relative to the toothed rack, wherein the bearing bushing is assigned to the first or second bearing.

14. The vehicle as claimed in claim 13, wherein precisely one of the first or second bearings is adjusted by the bearing bushing such that a position of the pinion shaft inside the one of the first or second bearings is changed transversely to a running direction of the first or second bearing.

15. The vehicle as claimed in claim 11, wherein the bearing bushing is assigned to a bearing that is linearly adjustable inside the housing.

16. A steering system comprising: a steering gear including a pinion shaft with a pinion that cooperates with a tooth of a toothed rack mounted inside a housing; and a bearing bushing that adjusts a position of the pinion shaft in the housing such that a tilt of the pinion shaft relative to the toothed rack is locked at an angular position inside the housing.

17. The steering system as claimed in claim 16, wherein the tilt of the pinion shaft is set inside a plane parallel to a running direction of the toothed rack.

18. The steering system as claimed in claim 16, wherein the pinion shaft is mounted inside the housing via an end-side first bearing and a second bearing opposite the first bearing relative to the toothed rack, wherein the bearing bushing is assigned to the first or second bearing.

19. The steering system as claimed in claim 18, wherein precisely one of the first or second bearings is adjusted by the bearing bushing such that a position of the pinion shaft inside the one of the first or second bearings is changed transversely to a running direction of the first or second bearing.

20. The steering system as claimed in claim 16, wherein the bearing bushing is assigned to a bearing that is linearly adjustable inside the housing.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0027] FIG. 1 is a perspective depiction of a steering gear according to the disclosure according to a first embodiment;

[0028] FIG. 2 is a sectional depiction of the steering gear from FIG. 1;

[0029] FIG. 3 is a sectional depiction along line in FIG. 2;

[0030] FIG. 4 is a sectional depiction of a steering gear according to the disclosure according to a second embodiment; and

[0031] FIG. 5 is a sectional depiction along line V-V in FIG. 4.

DETAILED DESCRIPTION

[0032] As required, detailed embodiments of the present disclosure are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the disclosure that may be embodied in various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present disclosure.

[0033] In the various Figures, the same parts always carry the same reference signs, so that these are usually only described once.

[0034] FIGS. 1 to 3 show a first embodiment of a steering gear 1 according to the disclosure, which is configured as a rack-and-pinion gear for a car, wherein FIG. 1 shows a perspective depiction of the entire steering gear 1. This comprises a pinion shaft 10 with a pinion 11 that cooperates with a toothing 31 of a toothed rack 30. In the FIGS. 1 to 3, X, Y and Z axes of a vehicle are drawn according to a proposed installation position of the steering gear 1. A running direction A of the toothed rack 30 is evident parallel to the Y axis, while a running direction B of the pinion shaft 10 runs (at least approximately) inside an X-Z plane. Both the pinion shaft 10 and the toothed rack 30 are mounted inside a housing 40. The toothed rack 30 is displaceable in a direction of the Y axis, and the pinion shaft 10 is rotatable about an axis corresponding to a pinion shaft running direction B.

[0035] The rotatable mounting of the pinion shaft 10 is achieved by three bearings 12, 13, 14. A first bearing 12 is arranged on an end side of the pinion shaft 10. A second bearing 13 is arranged opposite the first bearing 12 relative to the pinion 11 or the toothed rack 30. Viewed from the pinion 11, a third bearing 14 is arranged on a far side of the second bearing 13. The precise configuration of the second bearing 13 and third bearing 14 is not relevant in this context; they may for example be roller bearings, which are received stationarily inside the housing 40.

[0036] To improve engagement between the toothing 31 and the pinion 11, the toothed rack 30 is loaded by a pressure piece 43 in a direction of the pinion shaft 10. The pressure piece 43 is in turn loaded by a spring 42 that rests on a closing piece 41. Despite this measure, a potential problem could be that the engagement between the pinion shaft 10 and toothed rack 30 is not optimal, which may e.g. lead to undesirable rattling noise. Whether this occurs depends in particular on a tilt of the pinion shaft 10 inside the housing 40 relative to the toothed rack 30. Even minor changes in tilt can decisively influence the engagement.

[0037] To avoid a need to produce the housing 40 with particularly tight tolerances, the first bearing 12 is adjustable such that a position of the pinion shaft 10 inside the first bearing 12 can be changed perpendicularly to the running direction B. As evident in particular from FIG. 3, the first bearing 12 has a bearing bushing 15 that serves as an adjustment element and has a circular outer contour 15.1 and, formed eccentrically thereto, an also circular inner contour 15.2. Because of a circular form of the outer contour 15.1, the bearing bushing 15 can be arranged in any arbitrary angular position about the pinion shaft 10. This corresponds to an adjustment movement E indicated by the double arrow in FIG. 3. Depending on setting, the inner contour 15.2 and an end of the pinion shaft 10 received therein move. The adjustment process can be compared to a pivot movement in which the second bearing 13 or the third bearing 14 forms a rotation point and a pivot angle is predefined by adjustment of the first bearing 12. Either the second bearing 13 or the third bearing 14 must have a degree of play in order to allow the adjustment. Due to a change in tilt inside a Y-Z plane, the running direction B of the pinion shaft 10 does not lie precisely in the X-Z plane, depending on setting.

[0038] It is evident that a further roller bearing could be arranged between the bearing bushing 15 and the pinion shaft 10, but this has been omitted here for reasons of clarity. Under certain circumstances, friction between the bearing bushing 15 and the housing 40 may be sufficient to prevent undesirable twisting during operation of the vehicle. If this is not the case, the bearing bushing can be locked relative to the housing 40 by a locking screw 16 after an optimal angular position has been found. To facilitate adjustment of an angular position, the bearing bushing 15 may have end-side structures for form-fit engagement with a tool, e.g. a hexagonal recess or similar.

[0039] FIGS. 4 and 5 show a second embodiment of a steering gear 1 according to the disclosure, which substantially corresponds to the embodiment shown in FIGS. 1 to 3 and to this extent is not explained again. Instead of the eccentric bearing bushing 15, the first bearing 12 has a bearing piece 17, inside of which one end of the pinion shaft 11 is received. Here again, a roller bearing (not shown) could be provided between the bearing piece 17 and the pinion shaft 11. The bearing piece 17 is linearly adjustable inside a guide channel 40.1 of the housing 40, wherein the double arrow in FIG. 5 again indicates adjustment movement E, which is parallel to the running direction A of the toothed rack 30 and to the Y axis. In this embodiment, friction forces between the bearing piece 17 and the housing 40 are not normally sufficient to prevent undesirable displacement during operation of the vehicle. For this reason, in general, a locking screw 18 shown in FIG. 4 must be provided that locks the bearing piece 17 after an optimal tilt of the pinion shaft 11 has been set.

[0040] Whereas in the first exemplary embodiment, an adjustment of the tilt of the pinion shaft inside the Y-Z plane parallel to the running direction A of the toothed rack always entails an adjustment within the X-Z plane, in the second exemplary embodiment a selective change of tilt inside the Y-Z plane is possible without changing the tilt inside the X-Z plane.

[0041] While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms of the disclosure. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the disclosure. Additionally, the features of various implementing embodiments may be combined to form further embodiments of the disclosure.