Abstract: The ball nut of a ball screw at the inner circumference of which a ball groove is provided, wound helically about the longitudinal axis for rolling balls, and at its outer circumference a roller bearing is arranged for rotatably supporting the ball nut, wherein the roller bearing has an inner ring which is supported by means of a support ring arranged on the ball nut in the axial support direction, wherein the support ring is arranged as a result of material deformation in the axial support direction with positive engagement on the ball nut.

Abstract: A roller transmission, in particular toroidal transmission, with infinitely variable transmission ratio, includes a friction wheel (6) disposed between a driving disk (2) and driven disk (3) and rotatably mounted to a swingable carrier (7). The friction wheel has a circumferential friction surface (8) for interaction with confronting end faces (4, 5) of both disks (2, 3). The friction wheel (6) is made of two sheet metal parts (9, 10) interconnected outside the friction surface (8) and defining a partition plane which is disposed substantially transversely to the rotation axis of the friction wheel (6), wherein at least one cavity (15) is arranged between both sheet metal parts (9, 10).