Torque variation absorbing device

摘要

A torque variation absorbing device includes a first flywheel and a second flywheel which are rotatable relative to each other via a ball bearing. A hysteresis mechanism is disposed between the first flywheel and the second flywheel so that the first flywheel and the second flywheel are biased in directions away from each other. The ball bearing includes an outer race, an inner race, and a plurality of balls disposed in a space defined between the outer race and the inner race. A ball inlet groove is formed in each of the outer race and the inner race so that the each ball inlet groove opens toward the hysteresis mechanism. The hysteresis mechanism pushes the outer race and the outer race pushes the balls so that the pushed balls push the inner race in a direction away from the hysteresis mechanism. The portion of a ball guide groove formed in the inner race pushed by the balls is continuous in a circumferential direction of the torque variation absorbing device so that an abrasion of the balls due to a discontinuous portion of the inner race does not occur.