Nsk Corporation

Kazuhiro Uemura

Katsuhiko Tanaka

Ikunori Sakatani

Hiroshi Nakajima

Toru Takamizawa

Shoji Noguchi

Keisuke Kimura

Tsutomu Abe

Hiromitsu Muraki

Hiroshi Narai

Hideo Okano

Etsuo Maeda

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.

Ball bearing

A fluid bearing motor having sufficient room for securing an air chamber for use in quickly discharging bubbles that have entered a thrust fluid bearing and a reservoir for supplying a lubricating fluid to the thrust fluid bearing. Moreover, the fluid bearing motor can easily be fabricated. The fluid bearing motor includes a shaft member,, a sleeve,cooperating with the shaft member and a thrust collar,which is fixed to the shaft member,and extended in the diametric direction. The circumferentially-directed contour of the outer peripheral face of the thrust collar,is made elliptic, so that a reservoir,and an air chamber,are formed between the outer peripheral face of the thrust collar,and the face,of the mating member (sleeve).

Fluid bearing motor

A disc drive device includes a rotational assembly which is adapted to mount a disc thereon and is rotatably driven by a motor. The rotational assembly is rotatably supported on a support assembly by a radial hydrodynamic fluid bearing and a thrust bearing. An axial load is applied to the thrust bearing by a magnetic attractive force of up to 30N and is greater than a dead weight of the rotational assembly.

Rotational assembly for disc drive device having small runout and reduced axial displacement

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

In order to produce bearing steels of long life and high reliability with a higher probability by utilizing parameters for cleanness evaluation that are related to the shortest life of bearings, in the present invention, the logarithmic decrease in the cumulative size distribution of oxide-type nonmetallic inclusions and the estimated maximum diameter of inclusion particles present per unit volume or unit area are determined from the particle size distribution of the oxide-type nonmetallic inclusions, and the cleanness of interest is specified on the basis of said logarithmic decrease or said estimated maximum inclusion diameter.

Growing community of inventors

Kanagawa, Japan

Kazuhiro Uemura