Ntn Corporation

Honda Motor Co., Ltd.

Yoshiyasu Nakano

Katsufumi Abe

Noriaki Fujii

Shinji Oishi

Keiko Yoshida

Kazuyoshi Harimoto

Yugo Yoshimura

Nobuhiro Kasahara

Masanori Satou

Akihiko Katayama

Masaru Kitagawa

Provided are a gear in which oil film formation between the tooth surfaces of gears rotating at high speed can be effected to a sufficient degree, in which generation of pitting, abrasion, and scoring is prevented, and which helps to prevent an increase in temperature and wear to achieve an improvement in durability, and a gear drive unit. A multitude of minute concave recesses are provided at random on a tooth surface, and an average area of the recesses is set to a range of 160 to 740 &#x3bc;m. Accordingly, the tooth surface can obtain a high oil film forming capacity. Thus, even under a low-viscosity/thin-lubrication condition in which the thickness of the oil film is extremely small, it is possible to achieve a long service life.

Gear and gear drive unit

Provided are a gear and a gear drive unit which allow oil film formation to a sufficient degree between tooth surfaces of gears rotating at high-speed and which help to prevent generation of pitting, abrasion, and prevent scoring, temperature rise, and wear to thereby achieve an improvement in terms of durability. A tooth surface is provided with a multitude of minute recesses arranged at random, in which an axial surface roughness parameter Ryni of the surface thus provided with the recesses is set to a range: 0.8 &#x3bc;m&#x2266;Ryni&#x2266;2.3 &#x3bc;m. As a result, the tooth surface is endowed with a high oil film formation performance, and it is possible to attain a long service life even under a low-viscosity/thin-lubrication condition in which the oil film is extremely thin.

A needle roller bearing comprises an outer ring having a plurality of outer ring members split by split lines extending in an axial direction of the bearing, a plurality of needle rollers arranged on an orbit surface of said outer ring so that they can roll thereon, and a cage holding the needle rollers at intervals. The outer ring member has a projection serving as a positioning engaging part which engages with a housing for positioning, and an engaging click protruding from an axial end of the outer ring member inward along a diameter to prevent the cage from moving in an axial direction, in positions shifted from its circumferential center.

Needle roller bearing

A needle roller bearing comprises an outer ring having a split part in a circumferential direction, a plurality of rollers which can roll along an inner diameter surface of the outer ring, and a cage holding the plurality of rollers. The outer ring has an engaging click protruding inward along a diameter at a width-direction end thereof to prevent the cage from moving in an axial direction.

The cam follower with roller according to the present invention includes a cam follower body having a roller supporting portion integrally formed therein, a supporting shaft of which both ends are fixed to the roller supporting portion, and a roller rotatably supported to the supporting shaft with a plurality of needle rollers interposed. At least one of the supporting shaft, needle roller and roller is formed of heat-resisting steel, and the both ends of the supporting shaft is caulked to be fixed to the supporting portion.

Cam follower with roller

It is aimed to prolong the life of a rocker arm in which rollers are housed in a full type form between a ring and a pin from a viewpoint completely different from the idea of improving the material. It is proposed to suitably control the relation between clearances in circumferential and radial directions for the rollers housed in a roller housing space formed between the outer peripheral surface of the pin and the inner peripheral surface of the ring.

Growing community of inventors

Iwata, Japan

Yoshiyasu Nakano