A hub assembly includes an inner rotatable hub having inboard and outboard axial ends, a radial flange extending outwardly from the outboard axial end and connectable with the wheel, an inner circumferential surface, and an opposing outer circumferential surface providing inboard and outboard inner races. An outer hub is disposed about the inner hub, connectable with the chassis and has inboard and outboard axial ends, an outer circumferential surface and an inner circumferential surface. The inner surface provides inboard and outboard outer races and a central surface section extending between the two outer races. First and second sets of rolling elements are disposed between the inner and outer races. One or more sensors are each disposed on the central surface section of the outer hub and are each configured to sense strain within the outer hub generated by the rolling elements.

A vehicle wheel bearing device (1) is equipped with a cage (7) in which a pocket (Pt) is formed by adjacent pillar sections (7b) and a base section (7a) that is therebetween, and which retains a ball (8) in the pocket (Pt). Formed in the pillar sections (7b) are a claw portion (7e) and another short claw portion (7g) which project towards adjacent pillar sections, as well as a notched section (7i) cut toward the base section from the distal end radially inward of the claw portions of the pillar sections (7b). When viewed from the axial direction, the shortest length in the one claw portion (7e) to the center of the ball and the shortest length in the other short claw portion (7g) to the center of the ball are different.

A hub assembly includes an inner rotatable hub having inboard and outboard axial ends, a radial flange extending outwardly from the outboard axial end and connectable with the wheel, an inner circumferential surface, and an opposing outer circumferential surface providing inboard and outboard inner races. An outer hub is disposed about the inner hub, connectable with the chassis and has inboard and outboard axial ends, an outer circumferential surface and an inner circumferential surface. The inner surface provides inboard and outboard outer races and a central surface section extending between the two outer races. First and second sets of rolling elements are disposed between the inner and outer races. One or more sensors are each disposed on the central surface section of the outer hub and are each configured to sense strain within the outer hub generated by the rolling elements.

A vehicle wheel bearing device (1) is equipped with a cage (7) in which a pocket (Pt) is formed by adjacent pillar sections (7b) and a base section (7a) that is therebetween, and which retains a ball (8) in the pocket (Pt). Formed in the pillar sections (7b) are a claw portion (7e) and another short claw portion (7g) which project towards adjacent pillar sections, as well as a notched section (7i) cut toward the base section from the distal end radially inward of the claw portions of the pillar sections (7b). When viewed from the axial direction, the shortest length in the one claw portion (7e) to the center of the ball and the shortest length in the other short claw portion (7g) to the center of the ball are different.

The invention provides a caster comprising a bracket, a first transmission device and two wheels. The two wheels are connected by a transmission screw and are fixed to the bracket. The first transmission device comprises an annular retaining portion and a plurality of first balls, the plurality of first balls are equiangularly arranged in a circumferential direction of the annular retaining portion, and opposite sides of the annular retaining portion are respectively embedded in the respective wheels. The caster of the invention can solve the problems in the prior art that it is difficult to control the gap between the two wheels, the resistance generated between the two wheels is large and noise is easily generated.

A bearing device for a vehicle wheel, which has an increased number of balls and in which the ease of mounting the balls is increased. The bearing device is configured such that each of the columns (7b) of the retainer (7) is provided with latch sections (7e) protruding toward adjacent columns (7b) and with cutouts. The front ends of the latches (7e) are located within an annular range having a radial width R1 defined between the outer peripheral circle of a ball (8) and a reference imaginary circle C1 having a diameter D1 centered on the center of the ball (8).

The invention provides a caster comprising a bracket, a first transmission device and two wheels. The two wheels are connected by a transmission screw and are fixed to the bracket. The first transmission device comprises an annular retaining portion and a plurality of first balls, the plurality of first balls are equiangularly arranged in a circumferential direction of the annular retaining portion, and opposite sides of the annular retaining portion are respectively embedded in the respective wheels. The caster of the invention can solve the problems in the prior art that it is difficult to control the gap between the two wheels, the resistance generated between the two wheels is large and noise is easily generated.

A cage of an angular ball bearing includes, with respect to a plurality of balls arranged between an outer member and an inner member, an annular portion positioned on one side in an axial direction of the angular ball bearing, and a plurality of pillar portions provided to extend from the annular portion to the other side in the axial direction. The pillar portions include a first flat surface portion contactable with the balls on one side in a circumferential direction of the angular ball bearing, and a second flat surface portion contactable with the balls on the other side in the circumferential direction and parallel to the first flat surface portion.

A spline-processing method is used for a wheel bearing. The wheel bearing includes outer and inner members. The inner member has formed on its inner periphery an interference-defined spline having a guide spline formed at an inboard-side end portion thereof. An intermediate component of the inner member includes a spline-formation inner peripheral surface having the interference-defined spline and the guide spline formed thereon, and a relief portion, which is formed on an outboard side with respect to the spline-formation inner peripheral surface, and has a diameter larger than that of the spline-formation inner peripheral surface. A punch used for the spline processing includes an integrated spline punch having an interference-defined spline forming surface to form the interference-defined spline, and a guide spline forming surface to form the guide spline. The integrated spline punch presses the spline-formation inner peripheral surface to form the interference-defined spline and the guide spline.

A bearing device for a vehicle wheel, which has an increased number of balls and in which the ease of mounting the balls is increased. The bearing device is configured such that each of the columns (7b) of the retainer (7) is provided with latch sections (7e) protruding toward adjacent columns (7b) and with cutouts. The front ends of the latches (7e) are located within an annular range having a radial width R1 defined between the outer peripheral circle of a ball (8) and a reference imaginary circle C1 having a diameter D1 centered on the center of the ball (8).