Ramp actuator and angular-contact ball bearing unit having a cold-formed outer ring and an embossed ramp contour, and method for producing a ramp disc

Abstract

A ramp actuator has a pivotable ramp disc, which on a first end face has at least one ramp, which is prepared for the rolling of a rolling body and, spaced apart therefrom, has a raceway for bearing rolling bodies of a rolling bearing prepared to receive radial and axial forces. A bearing ring can be fixed on a shaft, wherein the ratio of the axial width of the ramp disc relative to the support height thereof is between 2.9 and 4.1 and the ratio between the ramp radius of the ramp of the ramp disc relative to the support height of the ramp disc is between 0.7 and 1.3. A method for producing a ramp disc for such a ramp actuator includes drawing, upset forging and embossing, preferably carried out in that order.

Claims

1. A ramp actuator for a motor vehicle transmission or a motor vehicle clutch, the ramp actuator having a pivotable ramp disc, which on a first end face has at least one ramp, which is prepared for the rolling of a rolling body and, spaced apart therefrom, has a raceway for bearing rolling bodies of a rolling bearing prepared to receive radial and axial forces, and having a bearing ring which can be fixed on a shaft, characterized in that, on the one hand, a ratio of an axial width of the ramp disc to a support height thereof is between 2.9 and 4.1 and ratio of a ramp radius of the ramp of the ramp disc to the support height of the ramp disc is between 0.7 and 1.3.

2. The ramp actuator according to claim 1, wherein a ratio of a diameter of the bearing rolling body, designed as a ball, to the shoulder height of the bearing ring is ≥3:2 and a wall thickness of the bearing ring at the apex of the bearing rolling body to the shoulder height of the bearing ring is between 0.2 and 0.6.

3. The ramp actuator according to claim 1, wherein the ramp disc is designed as a sheet metal part produced without producing shavings.

4. The ramp actuator according to claim 1, wherein the rolling bearing is an angular contact ball bearing.

5. The ramp actuator according to claim 1, wherein there are three ramps which are separated in a segment-like manner over the circumference of the end face of the ramp disc and which have a concave contour.

6. The ramp actuator according to claim 1, wherein the end face of the ramp disc is provided by a flange, the flange having a plurality of features evenly distributed over the circumference, each feature being either a radially protruding projection or an end-face groove.

7. A method for producing a ramp disc for a ramp actuator according to claim 1, the method comprising drawing, upset forging, and embossing.

8. The method according to claim 7, wherein a smallest radial and/or axial wall thickness of the ramp disc is greater than a thickness of the starting material thereof for the ramp disc.

9. The method according to claim 7, wherein the ramp disc is cut and/or perforated between the drawing and the upset forging.

10. The method according claim 7, wherein a distance between the ramp surface and the raceway on the inside of the ramp disc for the balls of the angular contact ball bearing is greater at the thinnest point than the thickness of the starting material for the ramp disc.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The ramp actuator and method are further explained below with the aid of a drawing. Various embodiments are shown in the process. In the figures:

[0025] FIG. 1 shows a perspective view of a first embodiment of a ramp actuator in a partially sectioned reproduction;

[0026] FIG. 2 shows a perspective view of only the pivotable ramp disc of the embodiment from FIG. 1;

[0027] FIG. 3 shows a further perspective view of the ramp disc from FIG. 2;

[0028] FIG. 4 shows a further perspective view of another ramp actuator;

[0029] FIG. 5 shows a longitudinal section through a single-row angular contact ball bearing and a ramp disc used, as is also shown in FIG. 4, for that special exemplary embodiment of a ramp actuator;

[0030] FIG. 6 shows a front view of the end face of the ramp disc with the three ramps thereof evenly distributed there and a rolling bearing designed as a single-row angular contact ball bearing located behind the ramp disc;

[0031] FIG. 7 shows a longitudinal section through the ramp actuator and of FIGS. 4 to 6;

[0032] FIGS. 8 to 11 show a further embodiment of a ramp actuator according to the type of representation in FIGS. 4 to 7; and

[0033] FIGS. 12 to 14 show the process sequence for producing the ramp disc.

DETAILED DESCRIPTION

[0034] The figures are only schematic in nature and serve only to understand the ramp actuator and method. The same elements are provided with the same reference signs.

[0035] FIG. 1 shows a first exemplary embodiment of a ramp actuator 1. The ramp actuator 1 has a pivotable ramp disc 2. The ramp side 2 can also be referred to as a pivotable ramp ring or pivot actuator disc. In anticipation of FIG. 10, reference is made to a toothed segment 3 designed as a toothing or projection for coupling an electric motor.

[0036] Returning to FIG. 1, the presence of a ramp 4 on a first end face 5 or a first end face should be noted. To be precise, there are three segment-like ramps 4 which have a concave surface for receiving one or more balls, for example two, three, four or five balls. These balls are not shown.

[0037] At a distance therefrom there is a raceway 6, on which bearing rolling bodies 7 have a rolling bearing 8 which is prepared to receive radial and axial forces. This rolling bearing 8 also has a bearing ring 9, namely a bearing inner ring 10, which is pre-pared for mounting/fixing on a shaft. Said shaft is not shown. The ramp disc 2 thus represents the bearing outer ring of the rolling bearing 8. A cage 11 can be provided to hold the bearing rolling bodies 7 in position.

[0038] As can be clearly seen in FIGS. 2 and 3, the ramp disc 2 thus has a flange/flange region 12 and a sleeve/sleeve region 13. The flange 12 provides the first end face 5 with the ramps 4, whereas the sleeve 13 provides the raceway 6 for the bearing rolling bodies 7 of the rolling bearing 8.

[0039] In FIG. 4 in particular, the presence of evenly distributed recesses 14 projecting in the radial direction can be seen on the outside of the flange 12 of the ramp disc 2. Notwithstanding this, there are recesses 14 of fundamentally different design in the embodiment of the ramp disc 2 according to the embodiment of FIG. 8, these recesses being designed as oil guide grooves 15 and in the manner of channels. In this embodiment, there is a radially protruding projection 16, which ultimately provides the toothed segment 3.

[0040] Coming back to the embodiment of FIG. 4, attention is also drawn to FIGS. 5 to 7. The axial width of the ramp disc 2 is provided with the reference sign 17. The support height is provided with the reference sign 18. The ramp radius is identified with the reference sign 19. The shoulder height of the ramp disc is provided with the reference sign 20. The diameter of the spherical bearing roller body 7 is provided with the reference sign 21. The shoulder height of the bearing ring is provided with the reference sign 22. The wall thickness of the bearing ring at the apex of the bearing rolling body 7 is provided with the reference sign 23. The wall thickness of the ramp disc at the apex of the bearing rolling body is provided with the reference sign 24. The wall thickness 24 is determined by the smallest distance between the concave surface of the raceway on the ramp 4 for the corresponding ball and the raceway on the radial inside of the ramp disc 2 for the bearing rolling bodies 7.

[0041] The rolling bearing 8 is a single-row angular contact ball bearing inclined at 35°±4°. In principle, however, pressure angles that are larger or smaller than 35° are also conceivable.

[0042] The exemplary embodiment of FIGS. 8 to 11 is highly similar to that of FIGS. 4 to 7 and differs in particular in the design of the oil guide grooves 15 or the recesses 14 and the projection 16.

[0043] Support heights, axial widths and shoulder heights are conventional and defined as indicated above. It should be noted that the support height 18 of the ramp disc 2 is measured between a plane through the end face 5 and a plane on the rear side 25, whereas the axial width 17 of the ramp disc 2 results between that plane through the first end face 5 and a plane through the opposite end face 26. See in particular FIG. 9. The wall thickness 24 of the ramp disc 2 at the apex of the bearing rolling body 7 is oriented in such a way that it is perpendicular to the concave surface in the region of the ramp radius 19 of the ramp disc 2.

[0044] The shoulder height 22 of the bearing ring 9 is caused by the distance between a plane on the radial outside of the bearing ring 9 and a likewise concentric reference plane through the apex of the bearing rolling body 7 in the bearing ring raceway 27. The contact line is referenced with reference sign 28. It is inclined to both a radially and an axially oriented axis. It has an inclination to the radially oriented axis of 35°±4°.

[0045] The method of production can be derived from the sequence of FIGS. 12, 13 and 14, wherein a cup 30 is created from a round blank 29 by means of a plurality of forming steps, in particular drawing steps, which is then formed into the ramp disc 2 by means of upset forging and embossing. It is important that the raceway for the bearing rolling bodies 7 can be introduced by means of an embossing process before or after the ramp is embossed.

LIST OF REFERENCE SIGNS

[0046] 1 Ramp actuator [0047] 2 Ramp disc/ramp ring [0048] 3 Toothed segment [0049] 4 Ramp [0050] 5 First end face of the ramp disc [0051] 6 Raceway [0052] 7 Bearing rolling body [0053] 8 Rolling bearing [0054] 9 Bearing ring [0055] 10 Bearing inner ring [0056] 11 Cage [0057] 12 Flange [0058] 13 Sleeve [0059] 14 Recess [0060] 15 Oil guide groove [0061] 16 Projection [0062] 17 Axial width of the ramp disc [0063] 18 Support height of the ramp disc [0064] 19 Ramp radius of the ramp disc [0065] 20 Shoulder height of the ramp disc [0066] 21 Diameter of the spherical bearing rolling body [0067] 22 Shoulder height of the bearing ring [0068] 23 Wall thickness of the bearing ring at the apex of the bearing rolling body [0069] 24 Wall thickness of the ramp disc at the apex of the bearing rolling body [0070] 25 Rear side [0071] 26 Second end face of the ramp disc [0072] 27 Bearing ring raceway [0073] 28 Contact line [0074] 29 Round blank [0075] 30 Cup