Noise Reducing Clutch Disengagement

The present invention relates to clutch bearings and particularly to arrangements for damping bearing movement. To avoid chatter in the confinement of relative movements of the fixed race of a self-centering clutch bearing and the sliding sleeve of a clutch disengagement, it is necessary to provide damping means.

For this purpose, it is known that a damping ring may be used, for example in the bore of the fixed race. The damping ring is provided with separate elastic members for damping movements of the bearing in the radial and the circumferential direction. This known damping ring requires a comparatively large structural space.

It is also known to provide a comparatively thin disc of an elastic material between the pressure plate of a sliding sleeve and the fixed race of a clutch bearing, with convexities entering into recesses of the plate, for example by projections arranged at the flange of the fixed race. However, these known damping means may be damaged in violent concussions.

The present invention is therefore directed to an improved clutch disengagement device particularly for motor vehicle clutches, wherein a clutch bearing is arranged to be radially displaceable on or in a sliding sleeve or the like. The fixed race of the bearing has a radially directed flange, preferably in contact with a plate connected to the sliding sleeve or the like, to provide engagement surface for the clutch actuating means. The damping ring is so constructed and arranged in the clutch bearing that it occupies little structural space and is not exposed to wear, even in violent concussions.

The damping ring according to this invention is preferably made of synthetic material and may be efficiently and inexpensively produced by casting or injection molding. It is moreover easily installed, and serves simultaneously as a seal against leakage of grease from the clutch bearing.

In addition, the present invention provides a favorable arrangement for damping relative movement of the clutch bearing, so that the damping members cannot be damaged even upon maximum displacement of the clutch bearing.

A further modification provides a simple method of securing the damping ring against rotation in addition, each damping member and end stop require only one aperture in the outer race of the clutch bearing and one recess in the plate finally, the damping member acts to seal the clutch bearing against grease leakage.

The invention will now be described in more detail with reference to preferred embodiment, and in conjunction with the appended drawings, wherein;

FIG. 1 is a sectional view showing a clutch disengagement device according to the present invention;

FIG. 2 shows a right side view of the clutch disengagement device of FIG 1;

FIG. 3 shows the outer race of the clutch bearing, in sectional view;

FIG. 4 shows a right side view of the outer race of FIG. 3 with damping ring in place;

FIG. 5 shows a cross section of a damping ring;

FIG. 6 shows a right side view of the damping ring of FIG. 5; and

FIG. 7 shows a detail Z of the damping ring of FIG. 5.

With reference to FIG. 1, a self-centering clutch bearing 1 is arranged on a sliding sleeve 2. The clutch bearing 1 consists of a massive inner race 3 having an axially extending portion 4 coming into contact with the clutch diaphragm spring, not shown. A cage 5 guides and retains rolling elements such as the balls 6. The outer race 7 is of sheet metal, drawn to a larger scale in FIG. 3, having a flange 8 directed radially inward in radially displaceable contact with a pressure plate 9, connected to the sliding sleeve 2, and a damping ring 10. The damping ring 10, shown separately in FIGS. 5 to 7, has on its periphery an encircling lip 11 (FIG. 7) inclined towards the rolling elements. The lip 11, upon insertion in the bore 12 of the outer race 7, is turned towards the centerline of the bearing and presses against the bore surface, so that the damping ring 10 seals the clutch bearing 1 against grease leakage on the side away from the clutch. On the side towards the clutch, the bearing 1 is sealed by a sheet metal cap 13 secured to the rim, directed radially outward, of the outer race 7.

The damping ring 10, on one face, has for example four damping elements 14 (FIG. 6) molded on, evenly spaced around the circumference, each consisting of two elastic tabs 15 arranged a short distance apart in the circumferential direction. The two tabs 15 of a damping member 14 are V-shaped, and arranged to protrude through apertures 16 (FIG. 4) in the flange 8 of the outer race 7 into recesses 17 (FIG. 2) of the pressure plate 9, and have their ends in contact with radially extending lateral surfaces 18 of the recesses 17. The damping ring 10 is secured against rotation in circumferential direction by two axially directed projections 19 molded on, each in contact with the radial surfaces 20 of an aperture 16 in the outer race 7. The tabs 15 of a damping member 14 are arranged between two projections 19, so that for each two projections 19 and two spring tabs 15, only one aperture 16 in the flange 8 of the outer race 7 is required. Radially over each damping member 14, end stops 21 are molded into the flange 8 of the outer race 7 to limit the radial displacement of the clutch bearing 1, which stops enter the recesses 17 in the plate 9 together with the damping members 14. The rectangular recesses 17 in plate 9, diametrically opposed to each other in pairs, with two mutually parallel lateral surfaces 18 of a recess 17 extending in radial direction, are so formed that when the clutch bearing 1 is concentrically arranged, the radial distance "a" between the damping members 14 and one lateral surface 22 of recesses 17 is the same size as the distance "b" between the lateral surfaces 18 of recesses 17 and the radially directed surfaces 23 of the end stops. As a result of this, the damping members 14 cannot be damaged upon maximum displacement of the clutch bearing 1, and a damping of relative movements in both radial and circumferential direction is achieved.

This invention is not limited to the embodiment described by way of example. Various design modifications within the spirit and scope of the present invention will be apparent to those skilled in the art. Thus, for example, in the plate 9, instead of four recesses 17, three or more than four recesses 17 may be provided to be entered by corresponding numbers of end stops 21 and damping members 14.