Nsk Corporation

Tatsuo Wakabayashi

Kazuto Kobayashi

Shigemi Tsukamoto

Hiroaki Ishikawa

Akira Takahashi

Eishi Shibuya

Katsuyuki Kawamura

Hirohide Ishida

Masamitsu Watanabe

Harumi Takanashi

Natsuki Sensui

Yasuhiro Ishimori

Masaru Hashida

Yoshihiro Kanayama

Nobuhiro Nakazawa

Kenichi Nagai

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.

Retainer for angular contact ball bearing, angular contact ball bearing, and hub unit bearing

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.

Hub unit bearing

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.

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.

Roller bearing unit

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.

Rolling bearing unit for wheel support

With respect to an outer ringin which a diameter Dof a first outer ring racewayis greater than a diameter Dof a second outer ring raceway(D&#x3e;D), a method is realized which facilitates the entry of a grinding toolinto an inner side of the outer ring when these both outer ring racewaysandare subjected to a grinding process. The grinding toolis made to enter the inner side of the outer ringthrough an opening on a side close to the first outer ring raceway

Manufacturing method of an outer ring for a bearing unit

In a wheel supporting rolling bearing unit in which pitch circle diameters of ballsin an outside row and an inside row are made different, contact angles &#x3b1;, &#x3b1;of the ballsin the two rows in a completed state are equal to each other. Initial contact angles &#x3b2;, &#x3b2;of the two rows are smaller than predetermined contact angles &#x3b1;, &#x3b1;. The extent [&#x3b1;&#x2212;&#x3b2;] to which the initial contact angle &#x3b2;of the ballsin the inside row is made smaller than the predetermined contact angle &#x3b1;of the ballsis made larger than the extent [&#x3b1;&#x2212;&#x3b2;] to which the initial contact angle &#x3b2;of the ballsin the outside row is made smaller than the predetermined contact angle &#x3b1;of the balls{[&#x3b1;&#x2212;&#x3b2;]&#x3e;[&#x3b1;&#x2212;&#x3b2;]}. By this configuration, imparting the predetermined contact angles &#x3b1;, &#x3b1;to the ballsin the two rows in the completed state, and the preloads and contact angles of the ballsin the two rows are made proper.

Method for manufacturing wheel supporting rolling bearing unit and method for inspecting double row rolling bearing unit

A wheel-supporting roller-bearing unit with air compressor that is compact and capable of keeping resistance against the rotation of the hublow 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 holesare located at a plurality of locations that are evenly spaced around the circumferential direction on the inside of a cylinder blockthat is connected and fastened to the inside end section in the axial direction of the hub. Pistonsfit inside these cylinder holesand are moved back and forth by a piston-drive mechanismas the cylinder blockrotates. The air compressoris a reciprocating-piston compressor, so it is possible to obtain the required air pressure regardless of rpm. Also, by placing a plurality of cylinder holesand pistonsat uniform intervals around in the circumferential direction, it is possible to suppress the resistance against the rotation of the hub

Rolling bearing unit for supporting a wheel with an air compressor

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.

Manufacturing method for bearing unit for support wheel

An IC tagis fixed to a central portion of an axially outer end portion face of a hubwhich is a rotational ring which makes up the wheel supporting bearing unit. Historical information of the wheel supporting bearing unitis stored in the IC tag. The historical information stored in the IC tagcan be read easily by the use of an external device. Due to this, the traceability of the wheel supporting bearing unitcan be increased.

Growing community of inventors

Fujisawa, Japan

Tatsuo Wakabayashi