Nsk Corporation

Daijiro Kitahara

Seizo Miyazaki

Toru Takamizawa

Shiro Saito

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 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

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.

Growing community of inventors

Tokyo, Japan

Daijiro Kitahara