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: A toroidal variable speed traction drive includes a driving disc and a driven disc. The discs have a common axis of rotation. The inner face of each disc is formed with a negative shape of a toroid. The drive further includes a plurality of roller assemblies interposed between the discs each roller assembly including a roller. The discs are urged together against the interposed roller assemblies by a clamping force. Each roller assembly is connected to a corresponding rotatable trunnion. The trunnion applies a steering force to the corresponding roller assembly at a point relative to the corresponding roller assembly; the applied steering force causing the roller of the corresponding roller assembly to steer and adopt different contact points. The point at which the steering force is applied is located offset from the trunnion rotational axis at a fixed distance.

Abstract: 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.

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 includes a driving disc and a driven disc. The discs have a common axis. A plurality of pairs of contacting rollers are interposed between the discs. The discs are urged together against the roller pairs (A) by a clamping force. Each of the rollers has a first rolling surface, by which it rolls on the other roller of the pair, and a second rolling surface by which it rolls on the toroidal surface of a corresponding disc. Each roller is mounted on a supporting axle about which it can rotate. The rotational axes of the rollers in a pair are supported in a plane that contains the two points where the rollers of the pair contact the discs. At least one of the rollers in each pair is adapted to be moved to adopt a stable position within the plane by the reactionary force exerted on it by the other roller of the pair.

Abstract: A toroidal variable speed traction drive is provided. The drive includes a driving disc and a driven disc. The discs have a common axis of rotation. The inner face of each disc is formed with a negative shape of a toroid. The drive further includes a plurality of roller assemblies interposed between the discs, each roller assembly including a roller. The discs are urged together against the interposed roller assemblies by a clamping force. Each roller assembly being connected to a corresponding rotatable trunnion. The trunnion applies a steering force to the corresponding roller assembly at a point relative to the corresponding roller assembly; the applied steering force causing the roller of the corresponding roller assembly to steer and adopt different contact points. The point at which the steering force is applied is located offset from the trunnion rotational axis at a fixed distance.