Ball bearing for supporting a spindle rotating at high speed

摘要

A ball bearing for supporting a spindle rotating at high speed is provided with at least one member of an inner race and a shaft having an inner raceway in an outer peripheral surface thereof, an outer race having an outer raceway in an inner peripheral surface thereof, and a plurality of balls having 3 mm or less in diameter which are rollingly provided between the inner raceway and the outer raceway, the balls being arranged along a pitch circle 11 mm or less in diameter. A bearing steel or stainless steel which is used to form the member having the raceway is reduced to 6% by volume or less in the amount of retained austenite, so that the raceways are improved in impression resistance. This eliminates the difficulty that the impression of the raceway lowers the acoustic characteristic.