Abstract: A notch communicating a pair of pockets adjacent to each other in the circumferential direction of pockets of a retainer is provided in a range from an end section on the axially one side to the axially intermediate section of each of pillar portions of the retainer for an angular contact ball bearing, the notch having a substantially rectangular opening shape as seen from the circumferential direction, and an inner surface of the notch having an outer diameter side flat surface portion arranged on the radially outer side from the center of a pocket and extending substantially linearly in the axial direction, an inner diameter side flat surface portion arranged on the radially inner side from the center and extending substantially linearly in the axial direction, and a back side flat surface portion arranged on the axially other side from the center and extending linearly in the radial direction.

Abstract: A hub unit bearing includes: an outer ring member; an inner ring member; and a cage. The cage includes a large-diameter side annular portion, a small-diameter side annular portion, pillar portions which axially couple the large-diameter side annular portion and the small-diameter side annular portion, and pockets which are formed between the pillar portions adjacent to each other in a circumferential direction. The pillar portions are formed to be inclined from the small-diameter side annular portion toward the large-diameter side annular portion. An outer diameter surface of the small-diameter side annular portion is formed as a tapered surface which is diameter-expanded toward the large-diameter side annular portion. At least one of the outer diameter surface of the cage and an inner diameter surface of the cage is formed as a cylindrical surface.

Abstract: A hub unit bearing includes a stationary side raceway ring, a rotating side raceway ring including a rotating side flange for fixing a vehicle wheel, and rolling elements rollably provided therebetween. The rotating side flange includes thin portions and thick portions arranged alternately in a circumferential direction. A hub bolt is serration-fitted to a bolt hole formed in each of the thick portions. An outer peripheral surface of the rotating side flange includes a large-diameter portion which has a larger radial thickness dimension with the bolt hole, a small-diameter portion which has a smaller radial thickness dimension with the bolt hole than the large-diameter portion, and a step portion which connects the large-diameter portion to the small-diameter portion. A serration-fitted portion does not radially overlap with the large-diameter portion.

Abstract: A hub unit bearing includes: an outer ring member; an inner ring member; and a cage. The cage includes a large-diameter side annular portion, a small-diameter side annular portion, pillar portions which axially couple the large-diameter side annular portion and the small-diameter side annular portion, and pockets which are formed between the pillar portions adjacent to each other in a circumferential direction. The pillar portions are formed to be inclined from the small-diameter side annular portion toward the large-diameter side annular portion. An outer diameter surface of the small-diameter side annular portion is formed as a tapered surface which is diameter-expanded toward the large-diameter side annular portion. At least one of the outer diameter surface of the cage and an inner diameter surface of the cage is formed as a cylindrical surface.

Abstract: A hub unit bearing includes a stationary side raceway ring, a rotating side raceway ring including a rotating side flange for fixing a vehicle wheel, and rolling elements rollably provided therebetween. The rotating side flange includes thin portions and thick portions arranged alternately in a circumferential direction. A hub bolt is serration-fitted to a bolt hole formed in each of the thick portions. An outer peripheral surface of the rotating side flange includes a large-diameter portion which has a larger radial thickness dimension with the bolt hole, a small-diameter portion which has a smaller radial thickness dimension with the bolt hole than the large-diameter portion, and a step portion which connects the large-diameter portion to the small-diameter portion. A serration-fitted portion does not radially overlap with the large-diameter portion.

Abstract: A seal device of a vehicle wheel-bearing unit includes a leak prevention seal lip and a scatter prevention seal lip, wherein a front end part of the leak prevention seal lip is in slidable contact with an axially inboard surface of a rotational-side flange in a state of having an interference throughout an entire circumference, and an axially middle part of the scatter prevention seal lip is provided at a radially more outer position than an indifferentiable part that is present between an axially inboard surface of a thick wall part and an axially inboard surface of a thin wall part and in a state where the axially middle part of the scatter prevention seal lip is radially overlapped with the indifferentiable part.

Abstract: A roller bearing unit with a combination seal ring. Between the outer peripheral edge of a rotation side circular ring part constituting a slinger and the inner peripheral surface of the stationary side cylindrical part of a metal insert constituting the seal ring, there is formed a labyrinth seal. Also, in such part of an elastic member constituting the slinger as intervenes between the labyrinth seal and seal lip serving as a side lip, there is formed an auxiliary seal lip having lower rigidity than the seal lip. The whole axial length of the auxiliary seal lip in its free state is set in the range of 5.5˜7.5 times the thickness dimension thereof and the ratio of interference is set in the range of 0˜20% of the whole axial length of the free-state thereof.

Abstract: A rolling bearing unit with decreased weight and improved durability is provided. An outer-ring core, manufactured using a ferrous alloy, forms an outer ring and is molded to an outer-ring main body that is manufactured using a synthetic resin containing reinforced fibers or using an aluminum alloy. Outer-ring raceway members are fitted into and fastened to mating concave surfaces of the inner circumferential surface of the outer-ring core that are exposed from the outer-ring main body. A hub core, manufactured using a ferrous alloy, forms a hub and is molded to a hub main body made using a synthetic resin containing reinforced fibers or using an aluminum alloy. Around the outer circumferential surface of the hub core, inner-ring raceway members are fitted onto and fastened to a fitting surface of the outer circumferential surface of the hub core that is exposed from the hub main body.

Abstract: A rolling bearing unit with decreased weight and improved durability is provided. An outer-ring core, manufactured using a ferrous alloy, forms an outer ring and is molded to an outer-ring main body that is manufactured using a synthetic resin containing reinforced fibers or using an aluminum alloy. Outer-ring raceway members are fitted into and fastened to mating concave surfaces of the inner circumferential surface of the outer-ring core that are exposed from the outer-ring main body. A hub core, manufactured using a ferrous alloy, forms a hub and is molded to a hub main body made using a synthetic resin containing reinforced fibers or using an aluminum alloy. Around the outer circumferential surface of the hub core, inner-ring raceway members are fitted onto and fastened to a fitting surface of the outer circumferential surface of the hub core that is exposed from the hub main body.

Abstract: A wheel supporting roller bearing in which a pitch circle diameter of an outboard row is larger than a pitch circle diameter of an inboard row. Thermally-hardened layers are formed, at two locations along an axial direction, in portions of an inner circumferential surface of an outer ring including outer ring raceways. The thermally-hardened layers are separated from each other by an unhardened portion in an axially middle portion of the outer ring. A non-cylindrical curved portion having an arcuate generatrix is provided on the axially middle portion of the inner circumferential surface of the outer ring between the outer ring raceways. A thickness of the thermally-hardened layer in the portion including the outer ring raceway on an axially outer side is larger than a thickness of the thermally-hardened layer in the portion including the outer ring raceway on the axially inner side.

Abstract: In a wheel supporting rolling bearing unit in which pitch circle diameters of balls 6a, 6b in an outside row and an inside row are made different, contact angles ?OUT, ?IN of the balls 6a, 6b in the two rows in a completed state are equal to each other. Initial contact angles ?OUT, ?IN of the two rows are smaller than predetermined contact angles ?OUT, ?IN. The extent [?IN??IN] to which the initial contact angle ?IN of the balls 6b, 6b in the inside row is made smaller than the predetermined contact angle ?IN of the balls 6b, 6b is made larger than the extent [?OUT??OUT] to which the initial contact angle ?OUT of the balls 6a, 6a in the outside row is made smaller than the predetermined contact angle ?OUT of the balls 6a, 6a {[?IN??IN]>[?OUT??OUT]}. By this configuration, imparting the predetermined contact angles ?OUT, ?IN to the balls 6a, 6b in the two rows in the completed state, and the preloads and contact angles of the balls 6a, 6b in the two rows are made proper.

Abstract: With respect to an outer ring 2b in which a diameter DB1 of a first outer ring raceway 10c is greater than a diameter DB2 of a second outer ring raceway 10b (DB1>DB2), a method is realized which facilitates the entry of a grinding tool 12 into an inner side of the outer ring when these both outer ring raceways 10c and 10b are subjected to a grinding process. The grinding tool 12 is made to enter the inner side of the outer ring 2b through an opening on a side close to the first outer ring raceway 10c.

Abstract: A wheel-supporting roller-bearing unit with air compressor that is compact and capable of keeping resistance against the rotation of the hub 4c low while at the same time maintaining good balance, and when necessary, is capable of obtaining compressed air having sufficient pressure regardless of the traveling speed of the vehicle. A plurality of cylinder holes 53 are located at a plurality of locations that are evenly spaced around the circumferential direction on the inside of a cylinder block 50 that is connected and fastened to the inside end section in the axial direction of the hub 4c. Pistons 54 fit inside these cylinder holes 53 and are moved back and forth by a piston-drive mechanism 62 as the cylinder block 50 rotates. The air compressor 2c is a reciprocating-piston compressor, so it is possible to obtain the required air pressure regardless of rpm.

Abstract: In a wheel supporting rolling bearing unit in which pitch circle diameters of balls 6a, 6b in an outside row and an inside row are made different, contact angles ?OUT, ?IN of the balls 6a, 6b in the two rows in a completed state are equal to each other. Initial contact angles ?OUT, ?IN of the two rows are smaller than predetermined contact angles ?OUT, ?IN. The extent [?IN??IN] to which the initial contact angle ?IN of the balls 6b, 6b in the inside row is made smaller than the predetermined contact angle ?IN of the balls 6b, 6b is made larger than the extent [?OUT??OUT] to which the initial contact angle ?OUT of the balls 6a, 6a in the outside row is made smaller than the predetermined contact angle ?OUT of the balls 6a, 6a {[?IN??IN]>[?OUT??OUT]}. By this configuration, imparting the predetermined contact angles ?OUT, ?IN to the balls 6a, 6b in the two rows in the completed state, and the preloads and contact angles of the balls 6a, 6b in the two rows are made proper.

Abstract: After a hub supporting member is mounted on an end portion of a spindle, correction work is applied to a ring-shaped supporting surface which is an end face of the hub supporting member, whereby perpendicularity of the supporting surface relative to a rotational center axis of the spindle is improved. Thereafter, while the hub main body is made to rotate together with the spindle in such a state that the mounting surface abuts with the supporting surface, grinding finishing work is applied to a cylindrical surface portion (a portion on which inner rings are fitted) of the hub main body. As a result, the perpendicularity of the mounting surface relative to the geometric center axis of the cylindrical surface portion is improved.

Abstract: There is provided a bearing unit including one raceway ring 2 which is mounted on a vehicle body, the other raceway ring 4 which is disposed to face the one raceway ring 2 and is mounted on a wheel, and a plurality of rolling elements 6, 8 which are built in rollably between an outer ring raceway 2s and an inner ring raceway 4s which are formed continuously on facing surfaces of both the raceway rings 2, 4, respectively, along a circumferential direction, at least either of the raceway rings 2, 4 having a connecting flange 12a or a mounting flange 12a at which the raceway ring is mounted on the vehicle body or the wheel, wherein both the raceway rings 2, 4 are formed entirely through cold forging with no machining given to a surface of the flange 2a, 12a, while a quenching and tempering treatment by electromagnetic induction and grinding are given to at least the outer ring raceway 2s and the outer ring raceway 4s.

Abstract: It is possible to obtain best performance in a structure in which moment rigidity can be improved by setting a pitch circle diameter of an outboard row to be larger than a pitch circle diameter of an inboard row. Thermally-hardened layers 16a, 16b are formed, at two locations along an axial direction, in portions of an inner circumferential surface of an outer ring 3 including outer ring raceways 12a, 12b. The thermally-hardened layers 16a, 16b are separated from each other by an unhardened portion 17 in an axially middle portion of the outer ring 3. A non-cylindrical curved portion 18 having an arcuate generatrix is provided on the axially middle portion of the inner circumferential surface of the outer ring 3, between the outer ring raceways 12a, 12b.

Abstract: With respect to an outer ring 2b in which a diameter DB1 of a first outer ring raceway 10c is greater than a diameter of a second outer ring raceway 10b (DB1>DB2), a method is realized which facilitates the entry of a grinding tool 12 into an inner side of the outer ring when these both outer ring raceways 10c and 10b are subjected to a grinding process. As shown in (A) to (B), the grinding tool 12 is made to enter the inner side of the outer ring 2b through an opening on a side close to the first outer ring raceway 10c between the openings at both ends of this outer ring 2b. This resolves the above-described problem.

Abstract: An IC tag 23 is fixed to a central portion of an axially outer end portion face of a hub 10a which is a rotational ring which makes up the wheel supporting bearing unit 5a. Historical information of the wheel supporting bearing unit 5a is stored in the IC tag 23. The historical information stored in the IC tag 23 can be read easily by the use of an external device 28. Due to this, the traceability of the wheel supporting bearing unit 5a can be increased.

Abstract: A wheel-supporting roller-bearing unit with air compressor that is compact and capable of keeping resistance against the rotation of the hub 4c low while at the same time maintaining good balance, and when necessary, is capable of obtaining compressed air having sufficient pressure regardless of the traveling speed of the vehicle. A plurality of cylinder holes 53 are located at a plurality of locations that are evenly spaced around the circumferential direction on the inside of a cylinder block 50 that is connected and fastened to the inside end section in the axial direction of the hub 4c. Pistons 54 fit inside these cylinder holes 53 and are moved back and forth by a piston-drive mechanism 62 as the cylinder block 50 rotates. The air compressor 2c is a reciprocating-piston compressor, so it is possible to obtain the required air pressure regardless of rpm.