Minebea Kabushiki-kaisha

Minebea Company, Limited

Yutaka Daikuhara

Eiichi Kobayashi

Rikuro Obara

Noriyuki Yoshimura

Shigenori Hoya

Akimi Furukoshi

Takaaki Tsuda

Tokushichi Furuta

Mineo Oyama

A bearing and a method for fabricating a bearing. The bearing is intended to be used in office automation equipment and the like is improved in impact resistance and load capacity. Its rotational accuracy will not deteriorate in long-term use and its quietness can be maintained over a long period of time. The bearing is an anti-friction bearing located between portions supporting a load and in relative motion to each other. The anti-friction bearing has an outer ring of 30 mm or less in diameter, in which high carbon chromium bearing steel constituting the anti-friction bearing includes the following compositions: C of 0.90-1.30 wt %, Si of 0.40-1.20 wt %, Mn of 0.90-1.0 wt %, and Cr of 0.90-1.70 wt %. After quenching, the tempering temperature used for this bearing is maintained in the range of 170&deg; C. and 250&deg; C. so that the amount of retained austenite in the surface layer after heat treatment is stabilized at 6 by volume or less.

Anti-friction bearing and method for fabricating anti-friction & bearing

In the retainer for a rolling bearing having the retainer comprising a plurality of pockets for supporting a plurality of rolling body in the circular direction at an equal spacing on one end side of the retainer, a plurality of recessed portions and in communicated with both of the back face and the periphery surface are formed, and after assembling the retainer on both ends of the bearing, the lubricant is applied from the recessed portion of the back face to the recessed portion of the periphery side and is made to flow in the bearing approximately uniformly in the circular direction to apply the sufficient amount of lubricant in the pocket of the front of the retainer and the connection portion to solve the variation of the bearing torque and reduce.

Retainer for rolling bearing

The present invention provides a bearing device reliable of shielding any material or fluid from moving between a fluid passage within a fluid system housing and an outside of the housing. In the above bearing device, a roller bearing (,) equipped with sealing plates (,) is fitted into a coupling bore (,) in an intake pipe (,) serving as the housing so that the roller bearing (,) can bear a shaft (,) of a butterfly valve disposed in a fluid passage (,) within the intake pipe (,). The outer race (,) and the inner race (,) of the roller bearing (,) are formed with annular grooves (,), respectively, and O-rings (,) are engagingly arranged on the interior of the annular grooves (,), respectively. With the bearing device having this structure, the O-rings (,) can prevent air, etc. from permeating into the intake passage (,) even though clearance (a, b) occurs in the engaged sections due to a dimensional error, difference in thermal expansion, etc.

Bearing device

The invention permits stacking of seals without possibility of the sticking of their synthetic rubber seal members to one another. Moreover, when assembling the seals to produce anti-friction bearings, the invention permits storing the seals as a stack in a stocker of an automatic assembler and, unlike the case of using silicon or like prior art anti-sticking material, substantially eliminates generation of fine particles or the like adversely affecting precision apparatuses and deteriorating the reliability thereof. In an anti-friction bearing comprising an inner ring (1), an outer ring (2), and rolling elements (3) provided between the inner and outer rings, a side gap between the inner and outer rings is closed by seals (4) of the invention, which each include a synthetic rubber seal member (6) and a surface active material (7) coated thereon.

Seal for an anti-friction bearing

To permit stacking of seals without possibility of the stacking of their synthetic rubber seal members to one another, permit, when assembling the seals to produce anti-friction bearings, storing the seals as a stack in a stocker of an automatic assembler and, unlike the case of using silicon or like prior art anti-sticking material, substantially eliminate generation of fine particles or the like adversely affecting precision apparatuses and deteriorating the reliability thereof. In an anti-friction bearing comprising an inner ring (1), an outer ring (2), and rolling elements (3) provided between the inner and outer rings, the side gap between the inner and outer rings is closed by seals (4), which each include a synthetic rubber seal member (6) and a surface active material (7) coated thereon.

Anti-friction bearing

To provide a stainless steel for anti-friction bearings, which is obtained by making its eutectic carbide contents finer in particle diameter and suppressing the generation of non-metallic substances to an extremely low level, thus having a homogenious and dense structure and permitting highly accurate machining. The provided stainless steel is composed of 0.60 to 0.75% of carbon, 10.5 to 13.5% of chromium, 1.0% or below of silicon and 0.3 to 0.8% of manganese, % being by weight, the remainder of the composition being iron and inevitably introduced impurities, has a hardness of HRC 58 or above, contains eutectic carbide particles of 10 .mu.m and below in diameter, and has oxygen and titanium concentrations each of 10 ppm or below.

Stainless steel for anti-friction bearing and method of making

In a motor having a spindle (5) on which an inner race (8) of a ball bearing is mounted, an outer peripheral surface of an end of the spindle (5) has a knurled portion (16) on which is mounted the inner race (8) which is fixed to the spindle (5) through an adhesive (18) filled in a clearance between an inner surface of the inner race (8) and the knurled portion (16). An annular groove (19), formed in the spindle (5) in an area adjacent to the knurled portion (16), is also filled with the adhesive (18) to further fix the inner race (8) to the spindle (5), which improves the adhesive bond between the inner race (8) and the spindle (5). Even when the ball bearing is a miniature one having a thin-wall inner race (8), there is no fear of deformation of the inner race (8) when the adhesive (18) is cured, which improves the rotational accuracy of the rotor.

Growing community of inventors

Nagano-ken, Japan

Yutaka Daikuhara