Abstract: An epicyclic traction drive transmission, including a carrier having a central axis, a sun shaft rotationally mounted within the carrier, a plurality of planet rollers mounted on the carrier, and an outer ring. Wedge rollers associated with each planet roller are located in a wedging slot defined between the ring and the planet roller. A resistance mechanism is provided so that the wedge roller's movement into the wedging slot is resisted by a force that is transferred to the carrier.

Abstract: An epicyclic traction drive transmission, including a carrier 7 having a central axis, a sun shaft 9 rotationally mounted within carrier 7 and positioned in the central axis, a plurality of planet rollers 4 mounted on carrier 7 and arranged to rotate on respective angularly equidistant axles 5, and rotationally engage the sun shaft 9, and an outer ring 1. A wedge roller 2,3 associated with each planet roller 4 is free to translate relative to carrier 7; and engages outer ring 1 and respective planetary roller 4 with a frictional or traction coefficient ?, and the wedge roller 2,3 defining a wedging angle ?, such that tan ?/2 is less than ?. In one form there are two wedge rollers 2,3 for each planet roller, allowing for a wedging action in either direction of rotation.

Abstract: A toroidal variable speed traction drive is provided. The drive comprises a driving toroidal disc assembly (4) and a driven toroidal disc assembly (3). The toroidal disc assemblies (3, 4) have a common axis of rotation. A plurality of roller assemblies are interposed between the toroidal discs (3, 4). Each roller assembly comprises at least one roller (16). The toroidal discs (3, 4) are urged together against the interposed roller assemblies by an axially directed clamping force. Each roller (16) of each roller assembly contacts each toroidal disc (3, 4) at contact points. The driving toroidal disc assembly (4) is driven by an input drive shaft (14) which provides an input torque. The driven toroidal disc (3) drives an output structure (5), that rotates around the common axis of rotation, the output structure (5, 12) driving an output shaft (13).

Abstract: A toroidal variable speed traction drive is provided. The drive comprises a driving toroidal disc assembly (4) and a driven toroidal disc assembly (3). The toroidal disc assemblies (3, 4) have a common axis of rotation. A plurality of roller assemblies are interposed between the toroidal discs (3, 4). Each roller assembly comprises at least one roller (16). The toroidal discs (3, 4) are urged together against the interposed roller assemblies by an axially directed clamping force. Each roller (16) of each roller assembly contacts each toroidal disc (3, 4) at contact points. The driving toroidal disc assembly (4) is driven by an input drive shaft (14) which provides an input torque. The driven toroidal disc (3) drives an output structure (5), that rotates around the common axis of rotation, the output structure (5, 12) driving an output shaft (13).