Disclosed is a toroidal variable speed traction drive including a driving disc and a driven disc, with a plurality of roller assemblies in between. Each roller assembly has a toroidal rolling surface to contact the toroidal surface of the corresponding disc, and a conical surface, for engaging the other roller in the assembly. An engagement is provide to prevent or reduce axial movement between the first and second rollers along the conical surface.

A continuously variable transmission in which a circular driver, positioned between and frictionally engaged with op posing surfaces of two oppositely rotatable disks, which are urged towards each other with a biasing mechanism, is mounted to, and is movable axially along, a drive shaft which extends radially from an input shaft which rotates the drive shaft about a longitudinal axis of the input shaft, and wherein output drive is taken from the disks via a speed balancing system.

A continuously variable transmission in which a circular driver, positioned between and frictionally engaged with op posing surfaces of two oppositely rotatable disks, which are urged towards each other with a biasing mechanism, is mounted to, and is movable axially along, a drive shaft which extends radially from an input shaft which rotates the drive shaft about a longitudinal axis of the input shaft, and wherein output drive is taken from the disks via a speed balancing system.

The invention relates to a continuously variable transmission with side speed regulating lead screw, and it comprises: a housing, a driving flat disc system, a power input system, a middle flat disc system, a power output system, a compaction system, a speed regulating ratio system of the middle flat disc, and serial and parallel structures. Since the previously most successful continuously variable transmission is the CVT continuously variable transmission, such continuously variable transmission transmits power depending on the conical disc and steel belt, and the limitation of the continuously variable transmission restrains the extensive application of such continuously variable transmission, whereas the continuously variable transmission of the invention transmits power depending on the mutual compaction between the driving flat disc and the middle flat disc as well as between the middle flat disc and the driven flat disc. The invention aims to solve the problem of too small transmission torque existing in previous continuously variable transmissions, and it realizes the objective of regulating the speed ratio by the movement of the middle flat disc up and down.