Method of manufacturing a rolling bearing unit for supporting a wheel

#This invention relates to a rolling bearing unit that supports an automobile wheel and a disk of a disk brake so that they rotate freely with respect to the suspension, as well as supports a caliper or support of the disk brake, and relates to the manufacturing method thereof.

#The wheel of an automobile, and the disk of a disk brake are supported by a rolling bearing unit for wheel support on the knuckle of a suspension so that they can rotate freely. On the other hand, the caliper or support of the disk brake is generally fastened to and supported by the knuckle. However, from the aspect of improving assemblibility of the caliper or support in an automobile or improving the handleability of the caliper or support, in recent years, fastening and supporting the caliper or support to a member on the stationary side of the wheel-supporting rolling bearing unit has been considered. For example, construction in which a flange for fastening to and supporting the caliper or support is located on the outer peripheral surface of the outer race, which is the stationary side member of the wheel-supporting rolling bearing unit, is disclosed in US Patent Application Publication No. 2003/0165280.

#FIG. 16 and FIG. 17 show an example of a wheel-supporting rolling bearing unit having a flange on the outer peripheral surface of the stationary side member for fastening to and supporting the caliper or support that differs from the construction that is publicly disclosed in US Patent Application Publication No. 2003/0165280, and was previously considered by the inventors. This wheel-supporting rolling bearing unit comprises: an outer race 1 that is a stationary side member, a hub 2 that is a rotating side member, and a plurality of balls 3 that are rolling bodies. Of these, the outer race 1 has a double row of outer raceways 4a, 4b formed around an inner peripheral surface thereof. Also, on a section toward the inside end of the outer peripheral surface, there is a connection flange 5 for connecting and fastening to the knuckle (not shown) and similarly, in a section in the circumferential direction of the middle section (section adjacent on the outside in the axial direction of the connection flange 5) there is a stationary side support flange 6 for supporting and fastening to the caliper or support (not shown). Here, ‘inside’ in the axial direction refers to the center side in the width direction of the vehicle when assembled in the vehicle, and is the right side in FIGS. 8, 12, and 16 to 18, is the bottom side in FIGS. 1 to 7, 9 to 11, 13 and 15, and is the top side in FIG. 14. On the other hand, the ‘outside’ in the axial direction, refers to the outside in the width direction of the vehicle, and is the left side in FIGS. 8, 12, and 16 to 18, the top side in FIGS. 1 to 7, 9 to 11, 13 and 15, and the bottom side in FIG. 14.

#FIG. 1 is a cross-sectional drawing showing a first embodiment of the invention, and shows the state in which a turning process is performed as the finishing process for the rotating side installation surface of the wheel-supporting rolling bearing unit.

#FIG. 2 is similarly a cross-sectional drawing showing the state in which a turning process is performed as the finishing process for the stationary side installation surface.

#FIG. 3 is a cross-sectional drawing showing another example of a wheel-supporting rolling bearing unit to which the present invention can be applied.

#FIG. 1 and FIG. 2 show a first embodiment of the present invention. The feature of this embodiment is a method of performing a turning process as the finishing process of the outside surface of the rotating side support flange 10, which is the installation surface on which the disk 9 of a disk brake (see FIGS. 4 to 6 and 18) is installed (rotating side installation surface 14), and similarly the outside surface of the stationary side support flange 6, which is the installation surface on which the support or caliper (not shown) is installed (stationary side installation surface 15). The construction and function of the other parts, such as the basic construction of the wheel-supporting rolling bearing unit is the same as that of the wheel-supporting rolling bearing unit shown in FIG. 16 and FIG. 17 as described above. Therefore, the same reference numbers will be given to identical parts, and any redundant explanation of those parts will be omitted or simplified, so that the explanation here will center on the features of this embodiment.

#In this embodiment, first, as shown in FIG. 1, studs 13 are press-fitted from the inside in the axial direction into the press-fit holes 12 that are formed at a plurality of locations in the circumferential direction of the rotating side support flange 10, and the wheel-supporting rolling bearing unit is constructed by assembling the outer race 1 and hub 2 by way of a plurality of balls 3. Also, in this state, the work of performing turning processing as the finishing process of the rotating side installation surface 14 can be performed by using the stationary side installation surface 15 as a reference surface. Therefore, in this embodiment, with the stationary side installation surface 15 brought into close contact with the side surface (bottom surface in FIG. 1) 18a of a support 17a, the stationary side support flange 6 is connected and fastened to the support 17a by a connection fastener such as a bolt or band (not shown). Also, in this state, while a drive apparatus (not shown) rotates and drives the hub 2, the turning process is performed on the rotating side installation surface 14 using tools 19a, 19b such as precision processing cutting tools. More specifically, one of the tools 19a is used to perform the turning process on the section of the rotating side installation surface 14 that is further outside in the radial direction than the circular ring shaped section (concave section 20 to be described later) that includes the openings of the press-fit holes 12. At the same time, the other tool 19b is used to similarly perform the turning process on the section that is further inside in the radial direction than the circular ring shaped section. When performing this kind of turning process, the tools 19a, 19b both move parallel with respect to the side surface 18a of the support 17a (stationary side surface 15). By performing the turning process on the rotating side installation surface 14 using the stationary side installation surface 15 as a reference surface, the flatness of the rotating side installation surface is improved, and the parallelism between the rotating side installation surface 14 and the stationary side installation surface 15 is improved.

#In the case of this embodiment, the circular ring shaped section of the rotating side installation surface 14, is a concave section 20 from before the studs 13 are press-fitted into the press-fit holes 12. By having this concave section 20, not only does it become difficult for distortion to occur on the rotating side installation surface 14 when press-fitting the studs 13 into these press-fit holes 12, but after the turning process is completed, the circular ring shaped section prevents protrusions in the axial direction more than other sections (sections where the turning process is performed using the tools 19a, 19b). Also, in this embodiment, turning of the rotating side installation surface 14 is performed after the studs 13 are press-fitted into the press-fit holes 12, so even in the case that distortions occur in the rotating side installation surface 14 due to press-fitting, it is possible to eliminate the distortions by the turning process.