Wälzlager

摘要

A ball bearing having a long life even at a high rotating speed of 2 million or higher in dmn value, wherein the radius of curvature of an inner ring groove (8) is increased and that of an outer ring groove (9) is set at 50.5 to 53 % of a ball diameter (da) so as to lower the heating value of an inner ring (2) and bring the heating value of an outer ring (3) close to that of the inner ring (2), whereby the heating value of the entire ball bearing (1) is suppressed and the life of the bearing can be prolonged at low cost without using a pre-loading method such as a large-flow-amount lubricating method or constant pressure pre-loading method and, in addition, a relation between a raceway track and the ball diameter and the number of balls are optimized so as to reduce a heating value and the composition of the material of the raceway is controlled so as to improve seizure resistance or a hard film is formed on a raceway groove surface so as to improve wear resistance, whereby a lower heating value, more seizure resistance, and more wear resistance can be achieved.