The invention relates to a single-row ball roller bearing in accordance with the features that form the preamble of patent claim 1, which can be used to particular advantage as a fixed bearing for the input or output shaft of a motor vehicle shift transmission, for example.
Ball roller bearings are rolling contact bearings with special roiling elements designed as ball rollers, which, starting from a basic ball shape, each have two side faces, which are formed as flats on said basic ball shape, which are arranged parallel to one another and between which the running surfaces of the ball rollers are in each case arranged. Ball roller bearings of this kind are widely known in many different versions in the form of single-, two-, three- or even four-row radial or angular contact ball roller bearings and, owing to the special shape of the rolling elements, they also require special cage designs in order, on the one hand, to limit a maximum angular position of the ball rollers relative to the longitudinal axis of the bearing and, on the other hand, to avoid wobbling of the ball rollers transversely to the direction of revolution thereof.
A single-row ball roller bearing of the type in question is already known, for example, from the German patent application with the official file reference 10 2008 016 977,3, which had not yet been published on the filing date of the present patent application, and essentially comprises an outer bearing ring, an inner bearing ring and a multiplicity of ball rollers arranged between said bearing rings, which ball rollers roll on the running surfaces thereof in two groove-shaped races machined into the inner side of the outer bearing ring and into the outer side of the inner bearing ring and are held at uniform distances from one another in the circumferential direction by a bearing cage.
This bearing cage is expediently designed as a window cage having two lateral angular flanges of identical diameter, a plurality of pocket webs which connect said angular flanges to one another, and a plurality of cage pockets which are separated from one another by said pocket webs and in each case have a capstan shape which is formed from a free contour which is arranged transversely with respect to the circumferential direction for inserting a ball roller into the bearing cage and from a cross-sectional contour of a ball roller, which cross-sectional contour is integrated in the former and is arranged longitudinally with respect to the circumferential direction. The free contour of the cage pockets, which is arranged transversely to the circumferential direction, corresponds to the shape of a section plane arranged directly on the transverse axis of a ball roller while the cross-sectional contour of the cage pockets, which is arranged longitudinally with respect to the circumferential direction, has the shape of a section plane arranged above the transverse axis of a ball roller, with the result that the side edges of the pocket webs are configured with the radii of the arcuate guide faces for the ball rollers, which guide faces correspond to running surfaces of two adjacent ball rollers. To produce a bearing cage of this kind, use is generally made of a sheet-metal strip, which is finished by profiling the angular flanges, punching the cage pockets, cutting to length to give the dimension of the circumference, rolling into a ring and welding the ends of the ring,
It has been found in practice, however, that the production of the bearing cage in the form described is subject to special technical problems, and furthermore the function of the bearing cage does not fully meet the specified requirements in terms of quality. It has thus been determined that the high filling ratio of the ball roller bearing and the associated high number of cage pockets in the bearing cage necessarily lead to it being possible for the pocket webs which separate the cage pockets from one another to be of only very narrow configuration and to said pocket webs therefore having only a low axial flexural stiffness. As a result, during the flanging of the lateral angular flanges which concludes the hearing assembly, axial bulges of the pocket webs occur, which bulges can lead to the ball rollers jamming in their cage pockets and ultimately to malfunctions of the ball roller bearing. The low flexural stiffness of the pocket webs can likewise lead to high fluctuations in the cage deflection during hearing operation, as a result of which undesirable high bearing noise additionally occurs in conjunction with the sharp edges of the punched-out cage pockets.
Starting from the disadvantages explained of the known prior art, it is therefore the underlying object of the invention to design a ball roller bearing, the bearing cage of which, while maintaining a maximum possible filling ratio of the ball roller bearing, has a design configuration such that the pocket webs thereof, which are of narrow configuration, do not tend to form axial bulges during the concluding flanging of the lateral angular flanges and do not cause any undesirable bearing noise during bearing operation.
According to the invention, this object is achieved, in the case of a ball roller bearing in accordance with the preamble of claim 1, in that the pocket webs have additional material profiles for axial reinforcement of the bearing cage, both between their side edges and on their guide faces, and the material profiles on their guide faces are configured at the same time as damping means against bearing noise.
Here, the invention is based on the finding that, as a result of targeted material profiles on the pocket webs of the bearing cage, a pocket geometry can be provided which firstly brings about a considerable axial reinforcement of the bearing cage and therefore avoids the axial bulges of the pocket webs, which axial bulges are produced during the concluding flanging of the lateral angular flanges, and which at the same time chamfers the sharp-edged guide faces on the cage pockets and therefore avoids undesirable bearing noise.
Preferred embodiments and/or developments of the ball roller bearing designed in accordance with the invention are described in the subclaims.
Thus, according to claim 2, it is provided as a first refinement of the ball roller bearing which is configured according to the invention that the material profiles between the side edges of the pocket webs are preferably configured as beads which are machined longitudinally centrally into their surfaces. This has proven particularly advantageous, since the beads can therefore be produced in a virtually cost neutral manner in one work operation with the punching of the cage pockets out of the sheet metal strip. Moreover, it is advantageous if the heads do not extend over the full length of the pocket webs, but rather are configured so as to end on both sides at the transition region of the pocket webs to the lateral angular flanges, since the elasticity which is required once again in this transition region for the flanging of the lateral angular flanges which concludes the bearing assembly can therefore be obtained. However, it is also possible to machine the beads into the underside of the pocket webs and/or to arrange them outside the longitudinal center of the pocket webs.
Moreover, it is also a second advantageous refinement of the ball roller bearing which is configured according to the invention according to claim 3 that the material profiles on the guide faces of the pocket webs are preferably configured as radially outwardly directed borders of material tabs which are additionally formed integrally onto the guide faces. Here, said material tabs are likewise produced with the punching of the cage pockets out of the sheet metal strip and are therefore likewise virtually cost-neutral. Here, the borders produced with said material tabs on the guide faces of the cage pockets contribute to the further axial reinforcement of the pocket webs of the hearing cage and at the same time have the further advantage that, as a result of the produced rigidity and as a result of the rounded profile of the guide faces which is produced, they act as damping means against the bearing noise produced during bearing operation during the forward and backward running of the ball rollers.
A preferred embodiment of the ball roller bearing designed in accordance with the invention is explained in greater detail below with reference to the attached drawings, in which:
A ball roller bearing 1 is clearly apparent from
Number | Date | Country | Kind |
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10 2009 042 166.1 | Sep 2009 | DE | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/EP2010/062106 | 8/19/2010 | WO | 00 | 3/16/2012 |