Ntn Corporation

Rino Fukami

Takashi Tsujimoto

Katsufumi Abe

Shinji Oishi

Kazuyuki Yamamoto

Makoto Nishikawa

Hiromitsu Kawai

Seiji Kanbara

Tsutomu Nakagawa

Masaru Tsuchiya

A roller and cage assembly () includes a roller () and a cage (). The cage has a plurality of annular portions (), a plurality of pillars () that couple the plurality of annular portions, and a pocket () formed between adjacent pillars. The pillars include a protrusion () that protrudes from a side wall surface towards the pocket and contacts the roller, which side wall surface configures the pocket, and within the protrusion, a plane facing the roller in a circumferential direction has a first plane (), and a second plane () connecting to the first plane, the first plane being a flat plane, and the second plane being a curved plane, or a flat plane inclined against the first plane.

Roller and cage assembly and planetary gear support structure

A needle roller and cage assembly include a cage having a width larger than a diameter thereof. Pillar sections of the cage each include roller retaining portions on radially inner and outer sides with respect to a roller pitch circle diameter and an oblique portion through which the roller retaining portions are continuous with each other. The oblique portion includes a first relief portion formed therein, for avoiding interference with a needle roller. The adjacent pillar sections form a pocket having a rectangular shape therebetween. The pocket includes a second relief portion in each of four corners thereof. The second relief portion extends in the axial direction of the cage from a position at which a short side of the pocket is elongated in a circumferential direction of the cage to an outer end of the roller retaining portion on the radially outer side.

Needle roller and cage assembly

A rolling contact bearing assembly includes a cage including two or more arcuate members each having a plurality of pockets defined therein for accommodating a corresponding number of rollers arranged consecutively in a circumferential direction to form a ring shaped assembly. The arcuate members are connected together by a retention ring, having an elasticity, over a circumference of the cage. The arcuate members are displaced radially outwardly against an elastic compressive force of the retention ring such that circumferential gaps are formed at joints between the neighboring arcuate members. The arcuate members are held in a condition movable in the circumferential direction by a distance equal to the size of the circumferential gaps.

Rolling bearing

The surfaces () of at least rolling elements () of a roller bearing for transmissions or differentials of automobiles are provided with innumerable minute, recess-shaped cavities at random and the surface roughness parameter Ryni of the surfaces provided with the cavities is in the range of 0.4-1.0 &#x3bc;m and the Sk value is not more than &#x2212;1.6.

Roller bearing for automobiles

At least the surfaces of rolling elements of a rolling bearing are each randomly formed with an innumerable number of microconcave-like pits. The surface roughness parameter Ryni of the surfaces provided with the pits is in a range of 0.4 to 1.0 &#x3bc;m, and the Sk value is &#x2212;1.6 or below.

An object is to reduce various losses occurring in a speed-reduction/differential gear apparatus for electric vehicles including a planetary-gear speed reducer and a differential device, thereby improving transmission efficiency of the driving force and increasing travel distance of the electric vehicle per battery charge. A speed-reduction/differential gear apparatus for electric vehicles includes a planetary-gear speed reducer and a differential device. A planetary gear mechanism in the speed reducer includes a speed-reducer-side carrier which has its inner diameter surface supported by a speed-reducer-side carrier support bearing. The invention provides proper mesh between in the pair of engaging teeth, leading to decrease in loss torque.

Reduction differential gear apparatus for electric vehicle

A thrust roller bearing () comprises a plurality of rollers () and an annular retainer () having a plurality of pockets () for containing the rollers (), not bent in a thickness direction and guided by the rollers. Each of first and second roller retaining parts () and () for retaining the roller () includes an arc-shaped curved line projecting toward the pocket in a cross section provided by cutting the retainer () by a plane containing the first and second roller retaining parts () and () and perpendicular to a center axis () of the roller ().

Thrust roller bearing

A thrust roller bearing includes a plurality of rollers, a retainer, an annular first track ring having a track surface, an outer periphery flange part, and a first claw part, and an annular second track ring having a track surface, an inner periphery flange part, and a second claw part. Bearing internal gaps to allow the eccentric rotation of the first track ring and the second track ring are provided between the outer periphery flange part and an outer edge part of the retainer, and between the inner periphery flange part and an inner edge part of the retainer. In addition, at least one of the first and second claw parts is a projection part formed by a bending process. Furthermore, an edge part of the retainer opposed to the projection part has a first slope part formed at a corner part on the side opposed to the track surface, and a second slope part having a radial length relatively shorter than that of the first slope part, and formed at a corner part on the opposite side in a thickness direction.

Thrust roller bearing and torque converter

At least on a surface of a rolling element of a rolling bearing, innumerable minute concave recesses are randomly formed. An area percentage of the recesses on the surface having the recesses formed thereon is in a range from 5 to 20%, and a surface roughness parameter Rymax of the surface having the recesses formed thereon is in a range of 0.4 to 1.0.

Provided are a rocker arm, a rocker shaft, a valve cap, an adjust screw, a pivot receiving member, and a valve of an arm type valve operating device that can suppress wear and pitching, and attain a long service life. A multiplicity of minute recesses are provided at random in contact portions with other members of those members. A surface provided with recesses has a surface roughness parameter Ryni that is in a range: 0.4 &#x3bc;m&#x2266;Ryni&#x2266;1.0 &#x3bc;m, and an Sk value of &#x2212;1.6 or less. Accordingly, contact surfaces exhibit a high oil-film-forming capacity, so a long service life is attained even under a condition of low viscosity, thin lubrication and extremely thin oil film.

Growing community of inventors

Iwata, Japan

Rino Fukami