Abstract: A continuously variable transmission comprises a housing (1) which accommodates two pulley sets (2, 3) and an endless flexible drive element (24) fitted around said pulley sets for transferring a torque, one of said pulley sets being provided with coupling means (14) for an ingoing shaft and the other with coupling means (22) for an outgoing shaft, said pulley sets each comprising two discs (4, 5) enclosing a groove which increases in radially outward direction, and screw drive means (6) for changing the distance between the two discs of each pulley set with the aim of changing the transmission ratio. Each disc is connected to a hub unit (7, 8) comprising a rolling element bearing means (9, 10, 30) for rotatably supporting the disc, each hub unit being axially displaceably supported with respect to the housing.

Abstract: A continuously variable transmission unit comprises two pulley sets (1, 2) which each comprises a pair of discs (66, 67) and a screw mechanism (12, 13) which is concentrated with respect to a pulley set (1, 2) for moving the discs (66, 67) of the pulley set (1, 2) towards and from each other, each pair of discs (66, 67) enclosing a V-shaped groove, a belt (5) stretching between the pulleys and accommodated in the grooves thereof, the screw mechanism (12, 13) being controllable by a control device, the discs (66, 67) of each pulley set (1, 2) being accommodated on a support shaft (68). The screw mechanism (12, 13) is accommodated in the bore in the shaft (68) and engaging at least on of the discs (66, 67).

Abstract: A variable diameter pulley comprises a pair of pulley main bodies (18, 19) connected to a rotating shaft (15), and a power transmission ring (20) interposed between the pulley main bodies. A belt (2) is passed around an outer periphery of the power transmission ring (20). The power transmission ring (20) is made eccentric relative to an axis (15a) of the rotating shaft (15) so as to be varied in its contact diameter (D). Both pulley main bodies (18, 19) are threadedly connected to the rotating shaft (15) by a torque cam mechanism (T) composed of a pair of thread connection mechanisms, which are inversely threaded to each other. Torque for effecting rotation of the respective pulley main bodies (18, 19) relative to the rotating shaft (15) is converted into a force, which causes both pulley main bodies (18, 19) to approach each other in equal amounts of stroke.

Abstract: A transmission using an endless metal band provides an infinitely variable output velocity for an essentially constant input velocity. The transmission can be controlled to give both forward and reverse directions, through zero output speed. A multi-layer band can be used for greater torque transmission.