Axial thrust washers are provided in the axial contact region of the bearing raceway of an unbalance shaft. The axial thrust washers do not extend beyond 360° in the circumferential direction, but extend only over a little more than the unbalance masses which extend in this region. The end sections of the axial thrust washers are bent over so that they are supported on the prominent unbalance masses, and form a funnel-like entry region for the rolling elements or for a cage of the rolling bearing which houses the rolling elements.