Nsk Corporation

Shoji Noguchi

Katsuhiko Tanaka

Takashi Ogawa

Ikunori Sakatani

Yasuhisa Terada

Takayuki Yatabe

Hiroya Achiha

Hisato Yamamoto

Tsuyoshi Koshi

Hiroshi Nakajima

Shigeru Endo

Chuichi Sato

Hiromitsu Muraki

Toru Takamizawa

Kazuhiro Uemura

Keisuke Kimura

Yasuo Murakami

Koji Ueda

Hiroshi Iwasa

Satoshi Kadokawa

Sumio Sugita

Hirotoshi Aramaki

Dai Kinno

Shinichi Natsumeda

Tetsu Takehara

Kenji Yakura

Yukio Ooura

Yasuo Utsumi

Akio Fujii

Ryoma Endou

Kenichi Shibazaki

Yasuyuki Shimasaki

Satoru Aihara

An outer ringis formed so as to have a large thickness and the pitch circle diameters Dp of ballsare shifted to the inside diameter side of the present ball bearing. The radiuses of curvature Ro, Ri of the section shapes of an outer ring racewayand an inner ring racewayare increased with respect to the diameter Db of the balls. At the same time, the diameter Db of the ballsand the thickness of an inner ringare not set excessively small to thereby be able not only to prevent Brinell impressions from being formed in the outer ring racewaybut also to prevent the inner ringfrom being damaged or cracked.

Ball bearing

An outer ring is formed so as to have a large thickness and the pitch circle diameters Dp of balls are shifted to the inside diameter side of the present ball bearing. The radiuses of curvature Ro, Ri of the section shapes of an outer ring raceway and an inner ring raceway are increased with respect to the diameter Db of the balls . At the same time, the diameter Db of the balls and the thickness of an inner ring are not set excessively small to thereby be able not only to prevent Brinell impressions from being formed in the outer ring raceway but also to prevent the inner ring from being damaged or cracked.

The locus of the displacement of the centers of the balls of a ball bearing is made elliptical and the radial bearing rigidity of the ball bearing in one radial direction is made greater than the radial bearing rigidity in another radial direction orthogonal to the one radial direction, or at least one of the axial length of the portion on the outer diametral surface of the inner race of the ball bearing which is fitted to a shaft and the axial length of the portion on the outer diametral surface of the outer race of the ball bearing which is fitted to a housing is made &frac12; or less of the bearing width of the ball bearing, whereby the radial rigidity of a ball bearing device is made very small as compared with the radial rigidity in the prior art. As a result, the stability of a swing arm system can be enhanced and higher speed and higher accuracy of control become possible.

Method of stabilizing high-speed control of ball bearing device

An outer ring is formed so as to have a large thickness and the pitch circle diameters Dp of balls are shifted to the inside diameter side of the present ball bearing. The radiuses of curvature Ro, Ri of the section shapes of an outer ring raceway and an inner ring raceway are increased with respect to the diameter Db of the balls At the same time, the diameter Db of the balls and the thickness of an inner ring are not set excessively small to thereby be able not only to prevent Brinell impressions from being formed in the outer ring raceway but also to prevent the inner ring from being damaged or cracked.

A ball bearing comprises an inner ring, an outer ring and a plurality of balls disposed between inner and outer rings. The number of the balls is made to be not smaller than 10. Lubricant is also enclosed between the inner and outer rings in such a manner that the amount of the lubricant is regulated not more than 8% of the volume of a space between the inner and outer rings.

A ball bearing in which the heat value in an inner ring is decreased and the heat value in an outer ring is brought closer to the heat value in the inner ring by making the radius of curvature for the inner ring groove larger, and defining the radius of curvature for the outer ring groove as 50.5% to 53.0% of the ball diameter. The arrangement of the present invention suppresses the heat value in the entire ball bearing and extends the bearing life at a reduced cost without using a large flow rate lubrication method or a preloading method such as constant preloading. In addition, a decrease in heat generation, seizing resistance and wear resistance can be attained further by optimizing a relation between the raceway groove and the ball diameter, by optimizing the number of balls, by controlling the ingredient composition for the material of the bearing ring, and by forming a hard deposition film on the surface of the raceway groove. Thus, according to the present invention, a ball bearing having a long life is provided even during high speed rotation at a dmn value of 2,000,000 or more.

A device is provided for measuring non-repetitive run-out and dynamic torque simultaneously for a radial rolling bearing, comprising a holder for holding one of the outer and inner races, a pushing member for pushing the holder in an axial direction without confining the holder in both of the radial and rotational directions, a drive shaft for rotatingly driving the other of the outer and inner races, a precision bearing device for rotatingly supporting the drive shaft, a displacement sensor for measuring radial displacement of the one of the outer and inner races, a wire having one end connected to a portion which rotates together with the one of the outer and inner races, and a torque sensor connected to the other end of the wire to measure dynamic torque applied to the one of the outer and inner races.

Device for measuring rotation accuracy and dynamic torque for radial rolling bearing

In the roller bearing, between an outer ring ( ) and an inner ring ( ), there are interposed a plurality of tapered rollers ( ) in a freely rollable manner. A flange portion ( ) is formed in the side portion of the inner ring ( ). The undercut allowance ratios of a contact ellipse formed due to mutual contact between the flange portion ( ) and the end face of the roller ( ) is set in the range of &minus;0.6&lE;(h&minus;b&minus;c)/b&lE;2, where a grinding undercut dimension on the flange portion ( ) is expressed as c, a contact point height between the flange portion ( ) and the end face of the roller ( ) is expressed as h, and the minor radius of a contact ellipse formed due to contact between the flange portion ( ) and the end face of the roller ( ) is expressed as b.

Rolling bearing

The locus of the displacement of the centers of the balls of a ball bearing is made elliptical and the radial bearing rigidity of the ball bearing in one radial direction is made greater than the radial bearing rigidity in another radial direction orthogonal to the one radial direction, or at least one of the axial length of the portion on the inner diametral surface of the inner race of the ball bearing which is fitted to a shaft and the axial length of the portion on the outer diametral surface of the outer race of the ball bearing which is fitted to a housing is made 1/2 or less of the bearing width of the ball bearing, whereby the radial rigidity of a ball bearing device is made very small as compared with the radial rigidity in the prior art. As a result, the stability of a swing arm system can be enhanced and higher speed and higher accuracy of control become possible.

Ball bearing device for a swing arm

A rolling bearing having a plurality of rolling elements interposed between an inner race and an outer race, wherein the number of the rolling elements is selected to be equal to a number having, as divisors, main low-frequency peak components of geometrical error of the inner and outer races to be assembled.

Rolling bearing and spindle apparatus

The rolling/sliding outer ring of the cam follower apparatus withstand peeling very well, even in sever lubrication conditions, through the steps that on the outer peripheral surface of the outer ring, the depth of the surface layer is taken to be 0 to 50 .mu.m, and the maximum residual compressive stress in this surface layer is between 50 and 110 kgf/mm.sup.2, the hardness of this surface layer is between Hv830 and Hv960, and the average wavelength of the very minute protrusions on the surface is less than 25 .mu.m, and the amount of residual austenite in the surface layer exceeds 7 volume %, after processing, while the inner peripheral surface, of the outer ring is superfinished.

Rolling-sliding mechanical member

A part with excellent wear resistance when subjected to both sliding friction and rolling friction has a layer in the range from 0 to 50 microns beneath the surface with a maximum compressive residual stress of at least 90 kgf/mm.sup.2, and a hardness of at least Hv 780. The average radius of curvature of tips of minute protrusions existing on the surface is made at least 90 microns.

Growing community of inventors

Kanagawa, Japan

Shoji Noguchi