ANTIFRICTION BEARING, ANTIFRICTION BEARING DEVICE, HARD DISK DRIVE DEVICE, AND MANUFACTURING METHOD OF ANTIFRICTION BEARING DEVICE

摘要

PROBLEM TO BE SOLVED: To prevent generating of rust while preventing generating of fluctuations in torque and resonant frequency, improve productivity and reduce out gas generation.;SOLUTION: An antifriction bearing device is provided, which comprises two antifriction bearings, each comprising an inner race and outer race that are formed of a metal material containing chrome and carbon and arranged coaxially each other, and a plurality of rolling elements, which are arranged in a circumferential direction with spaces within an annular gap between the inner and outer races, the two antifriction bearings being aligned with a space in an axial direction; and a shaft 31 which is fitted to each of inner races of the two first and second antifriction bearings, where the end face of an inner race 21 in an axial direction of a second antifriction bearing 20 forms a chrome weighting layer Z with a chrome content more than that of the inside of the inner race 21; and the inner race 21 is laser welded to the corresponding shaft 31.;COPYRIGHT: (C)2014,JPO&INPIT