Bearing apparatus for wheel

#The present invention relates to a bearing apparatus for a wheel for supporting a wheel of an automobile, and more particularly to a bearing apparatus for a wheel of a type that a hub, an outer joint member of a constant velocity universal joint and double rows of wheel bearings are united and at least one of the double rows of inner raceways is integrally formed in the outer joint member, or of a type that one of the inner raceways is directly formed in the hub and another of the inner raceways is formed in an inner race fitted to the hub.

#Driving wheels of the automobile such as rear wheels of an FR vehicle, front wheels of an FF vehicle and all wheels of a 4WD vehicle are supported to a suspension apparatus by a bearing apparatus for wheels. The bearing apparatus mentioned above is structured, as shown in FIG. 43, such that a hub 10, a bearing 20 and a constant velocity universal joint 30 are united, one inner raceway 12 of double rows of inner raceways is formed in the hub 10, and another inner raceway 42 is formed in an outer joint member 40 of the constant velocity universal joint 30.

#The hub 10 has a flange 14 for supporting the wheel, and the inner raceway 12 is formed on an outer peripheral surface close to the flange 14. The outer joint member 40 of the constant velocity universal joint 30 is constituted by a bowl-shaped mouth portion 43 and a solid stem portion 45, and is serration fitted to the hub 10 at the stem portion 45 and a shoulder surface 44 thereof is brought into contact with an end surface of the hub 10. The inner raceway 42 is formed on an outer peripheral surface close to the stem portion 45 in the mouth portion 43 of the outer joint member 40. Double rows of outer raceways 22 opposing to the inner raceways 12, 42 are formed on an inner peripheral surface of an outer member 21 (hereinafter, refer to as an outer race) of the bearing 20. Rolling elements 29 are assembled between the inner raceways 12, 42 and the outer raceways 22.

#FIG. 1 is a vertical cross sectional view of a bearing apparatus for a wheel showing an embodiment;

#FIG. 2 is a vertical cross sectional view for explaining a caulking process;

#FIG. 3 is a front elevational view of an outer joint member showing a particular embodiment of an uneven portion;

#An embodiment according to the present invention will be described with reference to the accompanying drawings.

#At first, a basic structure will be described with reference to FIG. 1. A bearing apparatus for a wheel has a hub 10, a bearing 20 and a constant velocity universal joint 30 as main constituting elements. In this case, a side close to an outer side of a vehicle in a state of being assembled in the vehicle is called as an outboard side (a left side in the drawing), and a side close to a center of the vehicle is called as an inboard side (a right side in the drawing).

#The hub 10 is provided with a flange 14 for mounting a wheel (not shown) at an end portion in the outboard side, and a hub bolt 15 for fixing a wheel disc to each of positions arranged at a uniform interval in a circumferential direction of the flange 14 is provided. An inner raceway 12 in the outboard side is formed on an outer peripheral surface close to the flange 14 of the hub 10. The hub 10 has an axial through hole 16 in an axial core portion.