Nsk Corporation

Seizo Miyazaki

Daijiro Kitahara

Toru Takamizawa

Shiro Saito

Hideo Ouchi

The sealing members () comprise a film member produced by forming an aluminum or alumina deposition film on at least one side surface of a film-like core material. One side surface outer circumferential rim part of the sealing members is bonded and fixed on the outer end surface of outer rings () constituting the rolling bearings ().

Sealing member, rolling bearing, thin motor, and bearing device

A bearing device comprising a shaft, a housing, a double row of bearings provided between the shaft and the housing and preloaded by a fixed-position preloading method, the double row of bearings having a pair of races with a gap therebetween for preload adjustment, and the bearing device further having a support member for supporting one side of the races in the pre-loading direction, and the support member provided on the side of one of the shaft and the housing.

Double row bearing device

An assembly method of a preload-adjustable rolling bearing unit comprising the steps of providing a shaft having a first inner raceway, an inner ring being press fitted onto the shaft and having a second inner raceway, such that a pitch of both raceways is set greater than a pitch required to give a predetermined preload, providing an outer ring having outer raceways, providing a plurality of balls to be fitted between the outer raceways of the outer ring, and the first and second inner raceways, positioning the balls equidistant apart in the circumferential direction, and vibrating the rolling bearing unit by means of piezo electric elements while moving the inner ring in the axial direction, measuring the resonant frequency of the rolling bearing unit with a vibration sensor to control the preload whereby the inner ring is pressed onto a shaft while vibrating with only a small amount of energy without scratching the raceway and rolling surfaces.

Preloading method for preload-adjustable rolling bearing and manufacture of the same

Preloading method for preload-adjustable rolling bearing

An assembly method of a preload-adjustable rolling bearing unit comprising the steps of providing a shaft having a first inner raceway, an inner ring being press fitted onto the shaft and having a second innor raceway, such that a pitch of both raceways is set greater than a pitch required to give a predetermined preload, providing an outer ring having outer raceways, providing a plurality of balls to be fitted between the outer raceways of the outer ring, and the first and second ir raceways, positioning the balls equidistant apart in the circumferential direction, and vibrating the rolling bearing unit by means of piezo electric elements while moving the inner ring In the axial direction, measuring the resonant frequency of the rolling bearing unit with a vibration sensor to control the preload whereby the inner ring is pressed onto a shaft while vibrating with only a small amount of energy without scratching the raceway and rolling surfaces.

The preload of the double row rolling bearing unit after completion is kept at a proper value regardless of the elastic deformation of the shaft caused when pushing the inner race in the axial direction wherein the balls are first installed in the bearing at the first pitch P,of the ball rows which is larger than the pitch p,in the state where the preload is proper and then preloaded to a pitch slightly smaller than the second pitch p,, so that the ball rows have the second pitch p,after the shaft is elastically restored.

Method for manufacturing pre-loaded double-row rolling bearing unit

An outer ring spacer for use in a double row rolling bearing unit fitted onto a shaft and comprising inner rings externally secured to the shaft having a pair of spaced apart inner ring raceways, a pair of outer rings having an inner peripheral face formed with outer ring raceways facing respective inner ring raceways, and a plurality of rolling elements provided between the inner ring raceways and outer ring raceways, the outer ring spacer fitted between the outer rings, and comprising a cylindrical spacer body formed with axially opposite parallel end faces abutted against the mutually facing end faces of the outer rings, and a displacement prevention ring internally secured to one axial end of the spacer body, and having a portion protruding from one of the parallel end faces of the spacer body so as to be engaged with the inner peripheral surface of one end portion of the outer rings to prevent the spacer body from being displaced radially.

Outer ring spacer for double row rolling bearing unit

The double-row ball bearing having a stationary shaft, a rotatable outer ring and balls between them is set in an inspection apparatus, so that the acoustic sound produced as the outer ring is rotated with the shaft inserted inside the balls is detected by a vibration pickup device to examine for the flaws on the surfaces of balls, shaft and outer ring.

Double-row, ball bearing and method of producing the same

The center of rotation of a shaft 2 with inner rings 11a externally secured thereto, is made concentric with the geometric center to thereby prevent the occurrence of runout during high speed rotation. To achieve this, the axial runout of the end portion of the shaft 2 is detected by a displacement sensor 23 while the shaft 2 is rotating. Then based on the measurement results, a portion of the shaft 2 is heated by a laser projector 24 to produce a structural change in this portion, thereby slightly bending the shaft 2. The center of rotation of the shaft 2 is thus made to coincide with the geometric center as a result of the bending.

Method of reducing axial runout of a rolling bearing unit and a rolling

A preloaded rolling bearing unit of the double row type has a pair of inner rings which have a raceway formed on a peripheral face at a location displaced in the axial direction from a central portion thereof, a first cylindrical portion axially protruding by a relatively large amount from one side of the raceway, and a second cylindrical portion axially protruding by a relatively small amount from the other side of the fourth raceway, whereby when the inner ring is engaged with an outer ring, the first cylindrical portion is positioned on an axially inner side of the bearing unit and the second cylindrical portion is positioned on an axially outer side of the bearing unit.

Preloaded rolling bearing units

An assembly method of a preload-adjustable rolling bearing unit comprising the steps of providing a shaft having a first inner raceway, an inner ring being press fitted onto the shaft and having a second inner raceway, such that a pitch of both raceways is set greater then a pitch required to give a predetermined preload, providing an outer ring having outer raceways, providing a plurality of balls to be fitted between the outer raceways of the outer ring, and the first and second inner raceways, positioning the balls equidistant apart in the circumferential direction, and vibrating the rolling bearing unit by means of piezo electric elements while moving the inner ring in the axial direction, measuring the resonant frequency of the rolling bearing unit with a vibration sensor to control the preload whereby the inner ring is pressed onto a shaft while vibrating with only a small amount of energy without scratching the raceway and rolling surfaces.

Preloading method for preload-adjustable rolling bearing and manufacture

A preload-adjustable bearing is constructed of a first rotary unit and second rotary unit. The first rotary unit has a first race and second race arranged immobile in a direction approaching toward each other. The second rotary unit has a third race and fourth race. The third race is located opposite the first race while the fourth race is located opposite the second race. The third race is fixed relative to the second rotary unit in a direction away from the fourth race. The fourth race is fitted with the second rotary unit with an interference formed therebetween movably relative to the second rotary unit. The fourth race is movable toward the third race under axial pressure applied between the fourth race and the second rotary unit. To preload the bearing, axial pressure is applied between the fourth race and the second rotary unit and then, the third race is moved toward the fourth race while measuring a preload between the first, second, third and fourth races and the first and second rows of balls so that the preload is set at a predetermined value. The bearing can be manufactured by forming at least one race groove in the fourth race after the fitting of the fourth race with the second rotary unit.

Growing community of inventors

Kanagawa-ken, Japan

Seizo Miyazaki