Abstract: A bearing device for a wheel prevents backlash in a circumferential direction and has excellent workability for connecting a hub wheel and an outer joint member of a constant velocity universal joint. The bearing device includes a recess-projection fitting structure in which the hub wheel and a shaft section, which is fitted in a hole of the hub wheel of the outer joint member of the constant velocity universal joint, are unitized together. In the recess-projection fitting structure, entire fitting regions among projections on the outer surface of the shaft section of the outer joint member and recesses, which fit on the projections, are brought into intimate contact with each other.

Abstract: A hub wheel (21) and an outer joint member (3) are coupled to each other through intermediation of a recess-projection fitting structure (M). The recess-projection fitting structure (M) can be separated by being applied with a pulling-out force in an axial direction under a state in which a bolt member (30) is removed, and can be re-formed by re-screwing the bolt member (30) into a bolt hole (5d). The hub wheel (21) comprises a receiving portion (23a) for receiving the bolt member (30). The shaft portion (5) has a small diameter portion (5a) serving as a fit-in portion to be fitted along an inner periphery of the receiving portion (23a) under a state in which the recess-projection fitting structure (M) is formed. The small diameter portion (5a) is used as a part for confirming the accuracy and the state of the recess-projection fitting structure (M).

Abstract: A grease composition for constant-velocity joints which is inexpensive and which and which has an improved anti-flaking property without using materials which have environmental burdens, and a constant-velocity joint enclosing this grease are provided. A grease composition for constant-velocity joints comprising: (a) a base oil, (b) a diurea thickener, (c) a zinc dialkyldithiophosphate, (d) a sulfurized molybdenum dialkyldithiocarbamate, (e) a zinc dialkyldithiocarbamate, and (f) a sulfur-nitrogen extreme pressure additive is provided.

Abstract: A bearing unit for driving wheels, and a manufacturing method thereof, includes a hub, a bearing, and a constant velocity universal joint, such that a process for assembling the bearing unit to a knuckle member 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: A wheel bearing device suppresses backlash in the circumferential direction and has excellent workability in connecting a hub wheel and an outer joint component of a constant velocity universal joint. The wheel bearing device has a stem shaft of an outer joint component of a constant velocity universal joint fitted into a hole section of a hub wheel that is integrated with the hub wheel by a projection and recess mating structure. In the projection and recess mating structure, an overall recess mating area of a projection is in close contact with a corresponding recess.

Abstract: A plunging type constant velocity universal joint includes an inner joint member having an outer peripheral surface in which a plurality of linear track grooves are formed in an axial direction and inclined with respect to an axial line, an outer joint member having an inner peripheral surface in which a plurality of linear track grooves are formed in the axial direction and inclined with respect to the axial line in a direction opposite to that of the track grooves of the inner joint member, and having an inside filled with a lubricant, balls incorporated in respective crossing portions between the track grooves of the inner and outer joint members, and a cage arranged between the outer peripheral surface and the inner peripheral surface for retaining the balls in the same plane, in which a large number of minute recesses are formed at random in surfaces of the balls.

Abstract: A fixed type constant velocity universal joint secures smooth rotation and reduces a load on a cage even at a large operating angle and when bearing large torque. The universal joint includes an outer joint member having an inner spherical surface in which track grooves are circumferentially formed in an axial direction and an inner joint member having an outer spherical surface in which track grooves paired with the track grooves of the outer joint member are circumferentially formed in the axial direction and multiple outer spherical surface portions circumferentially arranged. Balls are interposed between the track grooves of the outer and inner joint members for transmitting torque. A cage is interposed between the inner spherical surface and the outer spherical surface for retaining the balls. A spherical surface angle of the outer spherical surface on a joint opening side is set to 12.5° or more.

Abstract: A hub wheel (21) and an outer joint member (3) are coupled to each other through intermediation of a recess-projection fitting structure (M). The recess-projection fitting structure (M) can be separated by being applied with a pulling-out force in an axial direction under a state in which a bolt member (30) is removed, and can be re-formed by re-screwing the bolt member (30) into a bolt hole (5d). The hub wheel (21) comprises a receiving portion (23a) for receiving the bolt member (30). The shaft portion (5) has a small diameter portion (5a) serving as a fit-in portion to be fitted along an inner periphery of the receiving portion (23a) under a state in which the recess-projection fitting structure (M) is formed. The small diameter portion (5a) is used as a part for confirming the accuracy and the state of the recess-projection fitting structure (M).

Abstract: A fixed-type constant velocity universal joint can sufficiently interpose a lubricant between a torque transmitting ball and a guide groove, and reduce frictional force. The fixed-type constant velocity universal joint of the present invention includes an outer joint member 1 that is filled with a lubricant and on which a guide groove 1b that extends in an axial direction is formed on a spherical inner circumferential surface 1a, an inner joint member 2 provided on an inner diameter side of the outer joint member 1 and on which a guide groove 2b that extends in the axial direction is formed on a spherical outer circumferential surface 2a, a torque transmitting ball 3 interposed between opposing guide grooves 1b and 2b of the outer joint member 1 and the inner joint member 2 such as to roll freely, and a cage 4 that holds each ball 3. Numerous miniscule recesses are randomly formed on a surface of the ball 3.

Abstract: A fixed type constant velocity universal joint includes an outer joint member having an inner spherical surface in which a plurality of track grooves extending in an axial direction are formed; an inner joint member having an outer spherical surface in which a plurality of track grooves extending in the axial direction while paired with the track grooves of the outer joint member are formed. A plurality of balls are interposed between the track grooves of each of the outer joint member and the inner joint member, for transmitting a torque, and a cage is interposed between the inner spherical surface of the outer joint member and the outer spherical surface of the inner joint member, for holding the balls.

Abstract: A cylindrical pilot portion (72) to be fitted to an inner periphery of a wheel (80) is formed at an inner diameter part of a brake rotor (70). A shape of a hub wheel, in particular, the shape on an outboard side is thus simplified, and the hub wheel can be formed at low cost through cold forging or the like.

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

Abstract: Provided is a bearing device for a wheel that can realize prevention of a backlash in a circumferential direction and is excellent in workability of connection of a hub wheel and an outer joint member of a constant velocity universal joint. Further, provided is a bearing device for a wheel that can prevent deterioration in NVH characteristics, which is caused by the backlash occurring in a joint section between the hub wheel and the constant velocity universal joint or between an outer member and a knuckle, and can perform rotation torque transmission with high accuracy. The bearing device includes a recess-projection fitting structure (M) in which the hub wheel (1) and a shaft section (12), which is fitted in a hole (22) of the hub wheel (1) of the outer joint member of the constant velocity universal joint (3) are unitized together.

Abstract: A grease composition for constant-velocity joints which is inexpensive and which and which has an improved anti-flaking property without using materials which have environmental burdens, and a constant-velocity joint enclosing this grease are provided. A grease composition for constant-velocity joints comprising: (a) a base oil, (b) a diurea thickener, (c) a zinc dialkyldithiophosphate, (d) a sulfurized molybdenum dialkyldithiocarbamate, (e) a zinc dialkyldithiocarbamate, and (f) a sulfur-nitrogen extreme pressure additive is provided.

Abstract: The present invention provides a fixed-type constant velocity universal joint that can sufficiently interpose a lubricant between a torque transmitting ball and a guide groove, and reduce frictional force. The fixed-type constant velocity universal joint of the present invention includes an outer joint member 1 that is filled with a lubricant and on which a guide groove 1b that extends in an axial direction is formed on a spherical inner circumferential surface 1a, an inner joint member 2 provided on an inner diameter side of the outer joint member 1 and on which a guide groove 2b that extends in the axial direction is formed on a spherical outer circumferential surface 2a, a torque transmitting ball 3 interposed between opposing guide grooves 1b and 2b of the outer joint member 1 and the inner joint member 2 such as to roll freely, and a cage 4 that holds each ball 3. Numerous miniscule recesses are randomly formed on a surface of the ball 3.

Abstract: Provided is a small-sized, lightweight, low-cost, and highly reliable bearing device for a driving wheel which needs no tapered spline, and eliminates a circumferential backlash in spline fitting portions to thereby prevent unusual noise. The bearing device for a driving wheel comprises an outer race (5) having an inner periphery in which double-row outer raceway surfaces (13, 14) are formed; a hub wheel (1) and an inner race (2) having outer peripheries in which double-row inner raceway surfaces (7, 8) opposed to the outer raceway surfaces (13, 14) are formed; and double-row rolling elements (3, 4) interposed between the outer raceway surfaces (13, 14) of the outer race (5) and the inner raceway surfaces (7, 8) of the hub wheel (1) and the inner race (2).

Abstract: To easily achieve reduction in weight and size and increase in durability even when contact force at contact portions with respect to balls increases.

Abstract: To increase a torque transmission efficiency without involving significant modification of a structure of a joint.

Abstract: Provided is a fixed type constant velocity universal joint capable of securing smooth rotation and reducing a load on a cage even at a large operating angle and at a time of bearing large torque.

Abstract: The present invention provides a wheel bearing device that can suppress backlash in the circumferential direction and has excellent workability in connecting a hub wheel and a outer joint component of a constant velocity universal joint. The wheel bearing device according to the present invention is that in which a stem shaft 12 of an outer joint component of a constant velocity universal joint 3 fitted into a hole section 22 of a hub wheel 1 is integrated with the hub wheel 1 by a projection and recess mating structure M. In the projection and recess mating structure M, an overall recess mating area 38 of a projection 35 is in close contact with a corresponding recess 36.