Abstract: The present invention firmly connects an inner joint component and a shaft of a constant velocity universal joint, making it difficult for backlash to occur. An axis hole inner diameter 26 of an inner member 20 of the constant velocity universal joint is unhardened, and a spline 54 serving as a recess and projection section running along a circumferential direction is formed on an axial end outer diameter 52 of the shaft 50. A hardened layer n is formed on the axial end outer diameter 52 of the shaft 50. The shaft 50 and the inner member 20 are joined by an axial end of the shaft 50 being pressed into the axis hole inner diameter of the inner member 20 to incuse a shape of said recess and projection section onto the axis hole inner diameter 26 of the inner member 20.

Abstract: A process for assembling to a knuckle member a bearing unit for driving wheels including a hub, a bearing, and a constant velocity universal joint is simplified. In order to achieve this, a hub (10) and an outer joint member (31) of an out-board side constant velocity universal joint (30) are plastically joined together. An outer peripheral surface (26a) of an outer member (26) is press-fitted into an inner peripheral surface of the knuckle member, and a maximum diameter dimension (D1) of the out-board side constant velocity universal joint (30) is set smaller than a minimum diameter dimension (Dn) of the knuckle member (6). Also, a maximum diameter dimension (D2) of an in-board side constant velocity universal joint (40) is set smaller than the minimum diameter dimension (Dn) of the knuckle member (6).

Abstract: To reduce the cost in a resin boot attaching construction, a groove depth a and groove width b of engaging groove 21 and the height c and width d of ridges 22 are set within the following dimensional ranges:a=0.5-1.5 mmb=3.0-5.0 mmand b/a.gtoreq.3c=0.1-0.5 mmd=1.0-0. mm (where d=0, the ridges 22 become edges.) The width of the boot band is wider than the width of the groove.

Abstract: A boot fixing portion (12) has an annular convex portion (17) integrally formed on the outer periphery thereof and an annular projection (19) integrally formed on the inner periphery thereof in opposed relation to the convex portion (17), the annular projection (19) being adapted to engage an engaging groove (18) formed in the outer periphery of the outer member (14) of a constant velocity joint (13).

Abstract: A cross-groove type homokinetic joint which requires no boot adaptor and is thus less expensive and which is provided with an arrangement for preventing the balls from dropping out while keeping a large working angle of the shaft. The cross-grooved homokinetic joint has an inner ring having grooves in its outer surface, balls received in the grooves of the inner ring, a cage retaining the balls, and an outer ring having grooves in its inner surface. The balls are guided by the grooves of the outer ring. This joint has no boot adaptor. The boot is directly fixed to the outer ring. A circlip is fitted on the inner surface of the outer ring near its open end to prevent the balls from dropping out.

Abstract: A grease composition for a tripod type constant velocity joint, which includes a base oil, a urea compound as a thickening agent, and not more than 10% by weight of at least one of (A) a molybdenum dialkyldithiocarbamate and (B) a molybdenum dialkyldithiophosphate or diaryldithiophosphate, in which the base oil has a kinematic viscosity of from 3.0 to 7.5 mm.sup.2 /sec at 100.degree. C. The grease composition applied to a tripod type constant velocity joint reduces the induced thrust force and thereby suppresses vibration, such as a shudder of a car body upon starting off and acceleration.