SEAL RING FOR BALL BEARING, AND THE BALL BEARING WITH THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a structure allowing reduction in dynamic torque by lengthening the total length Lof an inner diameter side inclination part 19 of a seal lip 14a without making a specification change of a ball bearing.SOLUTION: An angle αof an inside continuous surface 22 of a continuous part 20 connecting both outer and inner diameter side inclination parts 18, 19 and forming the seal lip 14a is set to at least 104° as shown in (A). With this configuration, the continuous part 20 enters the inner diameter side of a waveform retainer to lengthen the total length Lof the inner diameter side inclination part 19. The surface pressure of a sliding contact part between the tip edge of the inner diameter side inclination part 19 and the end outer peripheral surface of an inner ring is kept low by that portion to reduce the dynamic torque of the ball bearing with a seal ring in which the seal ring 3a is built.