SHAFT ADJUSTER

Abstract

The disclosu rerelates to a shaft adjuster, in particular a camshaft adjuster, comprising a drive gear having a spur gear toothing and a clamping gear which is arranged coaxially relative to the drive gear and which is loaded by a spring acting in the circumferential direction. The spring is also designed as an axial securing element for axially securing the clamping gear on the drive gear .

Claims

1. A shaft adjuster, comprising; a drive gear having a spur gear toothing, and a clamping gear arranged coaxially relative to the drive gear, the clamping gear loaded by a springacting in a circumferential direction, the spring is configured to axially secure the clamping gear on the drive gear.

2. The shaft adjuster according to claim 1, wherein the spring engages in a tangential groove arranged on an outer peripheral surface of the drive gear, the tangential groove formed in an annular projection of the drive gear and the annular projection projecting beyond the spur gear toothingan axial direction.

3. The shaft adjuster according to claim 2, wherein the clamping gear is arranged in the axial direction betweenspur gear toothingof the drive gear and the spring.

4. The shaft adjuster according to claim 3, wherein the tangential grooveis interrupted by an axial grooveconfigured to be engaged by a first securing end of the spring, the first securing end directed in a radially inward direction.

5. The shaft adjuster according to claim 4, the first securing end is drawn inwards, and an inner contour of the first securing end is rounded with the inner contour configured to engage the axial groove.

6. The shaft adjuster according to claim 3, the clamping gear has clamping gear toothing and a torque support contour projecting beyond the clamping gear toothing in the axial direction, and the spring is configured to engage the torque support contour.

7. The shaft adjuster according to claim 6, wherein the torque support contour is interrupted by a first opening arranged in the clamping gear, securing element and aligned with a second opening arranged in the drive gear.

8. The shaft adjuster according to claim 1, wherein a reduction gear configured as a harmonic drive includes internal toothing arranged on an inner peripheral surface of the drive gear.

9. The shaft adjuster according to claim 8, wherein a compensating coupling of the harmonic drive an Oldham disc arranged in an interior space of the harmonic drive enclosed by the drive gear.

10. The shaft adjuster according to claim 8, wherein an electrical actuation of the harmonic drive is provided by an electric motor having a compensating element.

11. The shaft adjuster of claim 1, wherein the shaft adjuster is a camshaft adjuster.

12. An electromechanical camshaft adjuster, comprising: a drive gear having a spur gear toothing, and a clamping gear arranged coaxially relative to the drive gear, the clamping gear biased via a torsion spring arranged within a tangential groove of the drive gear, and the torsion spring is configured to axially secure the clamping gear on the drive gear, and the clamping gear is arranged between the spur gear toothing and the torsion spring in an axial direction.

13. The electromechanical camshaft adjuster of claim 12, wherein the tangential groove is interrupted by an axial groove configured to be engaged by a first securing end of the torsion spring, the first securing end directed in a radially inward direction.

14. The electromechanical camshaft adjuster of claim 12, wherein a reduction gear configured as a harmonic drive includes internal toothing arranged on an inner peripheral surface of the drive gear.

15. The electromechanical camshaft adjuster of claim 12, wherein the clamping gear has clamping gear toothing and a torque support contour projecting beyond the clamping gear toothing in an axial direction, and the torsion spring is configured to engage the torque support contour.

16. The electromechanical camshaft adjuster of claim 15, wherein the torque support contour is interrupted by a first opening arranged in the clamping gear, the first opening: i) configured to receive a securing element for fixing an angular position of the clamping gear relative to the drive gear, and ii) aligned with a second opening arranged in the drive gear.

17. An electromechanical camshaft adjuster, comprising: a drive gear having a spur gear toothing and an annular projection, and a clamping gear arranged on the annular projection and axially retained on the annular projection via a torsion spring configured to load the clamping gear in a circumferential direction, and the annular projection having: internal toothing configured for a harmonic drive, and a tangential groove configured to receive the torsion spring.

18. The electromechanical camshaft adjuster of claim 17, wherein the tangential groove is interrupted by an axial groove configured to be engaged by a first securing end of the torsion spring, the first securing end directed in a radially inward direction.

19. The electromechanical camshaft adjuster of claim 17, wherein the clamping gear has clamping gear toothing and a torque support contour projecting beyond the clamping gear toothing in an axial direction, and the torsion spring is configured to engage the torque support contour.

20. The electromechanical camshaft adjuster of claim 19, wherein the torque support contour is interrupted by a first opening arranged in the clamping gear, the first opening: i) configured to receive a securing element for fixing an angular position of the clamping gear relative to the drive gear, and ii) aligned with a second opening arranged in the drive gear.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In the following, an exemplary embodiment of the disclosure is explained in more detail by means of a drawing. In the figures, partly simplified:

[0020] FIG. 1 shows a perspective view of a shaft adjuster, in particular a camshaft adjuster,

[0021] FIG. 2 shows a detail of a drive gear of the shaft adjuster,

[0022] FIG. 3 shows a clamping gear of the shaft adjuster,

[0023] FIG. 4 shows a C-spring of the shaft adjuster,

[0024] FIG. 5 shows the shaft adjuster including a securing element, and

[0025] FIG. 6 shows a detail view of the arrangement according to FIG. 5.

DETAILED DESCRIPTION

[0026] A shaft adjuster identified overall by the reference numeral 1 is provided as an electromechanical camshaft adjuster for use in a reciprocating piston engine of a motor vehicle. With regard to the principal function of the camshaft adjuster 1, reference is made to the prior art cited at the outset.

[0027] The shaft adjuster 1 comprises a drive gear 2, which is provided with a spur gear toothing 3 and is driven via a gear drive from the crankshaft of the reciprocating engine. In order to take play out of the gear drive, there is another, narrower gear wheel next to the drive gear 2, namely the clamping gear 4, the toothing of which is labeled with the reference symbol 5 and has the same profile as the toothing 3 of the drive gear 2.

[0028] The two gear wheels 2, 4 are biased against each other in the circumferential direction by a C-shaped spring 6 acting as a torsion spring, i.e., a C-spring, so that a driven gear, not shown, of the gear drive, which meshes with both the toothing 3 and the toothing 5, cooperates with the arrangement of the two gear wheels 2, 4 without play.

[0029] The spring 6 snaps into a tangential groove 7 of the drive gear 2. The tangential groove 7 is located in an annular projection 8, which is integrally connected to the rest of the drive gear 2 and protrudes beyond the spur gear toothing 3 in the axial direction, relative to the central axis of the gear wheels 2, 4, which is also the central axis of the entire shaft adjuster 1. The clamping gear 4 is arranged axially between the spur gear toothing 3 and the C-spring 6. This prevents displacement of the clamping gear 4 on the annular projection 8 in the axial direction, on the one hand, by the spur gear toothing 3 and, on the other hand, by the C-spring 6.

[0030] The tangential groove 7 is interrupted by an axial groove 9, which is used to mount a first securing end 10 of the spring 6. In contrast to the axial groove 9, which has a rectangular cross section, the securing end 10 of the spring 6 is rounded and drawn inwards. This means that in the area of the securing end 10 the inside diameter of the spring 6 is reduced in comparison to other areas of the spring 10. A rounded inner contour of the securing end 10 is labeled with reference symbol 11. The second securing end of the spring 6, labeled with the reference symbol 12, has a recess 13 on the outside, which engages in a torque support contour 14 of the clamping gear 4 from the inside. The torque support contour 14 has the shape of a ring segment, which is interrupted by an opening 15. The opening 15 is aligned with an opening 16 located in the drive gear 2 and enables the insertion of a securing element 17 which fixes the angular position of the clamping gear 4 relative to the drive gear 2.

[0031] The camshaft adjuster 1 comprises a harmonic drive 18 as a three-shaft drive. A wave generator 19 of the harmonic drive 18 works with a ball bearing 20 as a roller bearing and causes the deformation of an elastic, toothed gear element, which interacts with internal toothing 21 on the inner peripheral surface of the drive gear 2. A compensating coupling 22 in the form of an Oldham coupling, which comprises an Oldham disc 23 as a compensating element, is also to be attributed to the harmonic drive 18. In an alternative embodiment, not shown, the Oldham disc 23 is omitted, wherein a compensating element is integrated into the electric motor, which actuates the wave generator 19 instead.

[0032] In the present case, an electrically driven, two-winged drive element, not shown, which rotates the Oldham disc 23 and thus actuates the wave generator 19, engages in two recesses 24 on the inner peripheral surface of the Oldham disc 23. In this case, the Oldham disc 23 can be displaced to a limited extent relative to the drive element, which is identical to or firmly connected to the rotor of an electric motor. In a direction orthogonal thereto, the Oldham disc 23 can be displaced within defined limits with respect to two pins 25 that are firmly connected to an inner ring of the wave generator 19. Overall, an axial offset between the electric motor, which actuates the wave generator 19, and the central axis of the harmonic drive 18, i.e., the axis of rotation of the shaft adjuster 1 and thus also the axis of rotation of the shaft to be adjusted, can be compensated. In the axial direction, the Oldham disc 23 is set back with respect to the end face of the annular projection 8. The Oldham disc 23 is thus arranged completely within the cavity that is formed by the drive gear 2.

TABLE-US-00001 1 Shaft adjuster 2 Spur gear toothing 3 Toothing 4 Tangenital groove 5 Drive gear 6 Clamping gear 7 Spring 8 Annular projection 9 Axial groove 10 First securing end 11 Inner contour 12 Second securing end 13 Recess 14 Torque support contour 15 Opening in the clamping gear 16 Operating in the drive 17 Securing element 18 Harmonic drive 19 Wave generator 20 Ball bearing 21 Inner toothing 22 Compensating coupling 23 Oldham disc 24 Recess 25 Pin