Variable ratio power transmission

Abstract

A variable ratio power transmission comprising a variator and a geared drive operable in parallel along respective loading paths which unite at at least one gearset. In a first embodiment, the variator is rewindable between its ratio extremities of operation to begin a successive variable mode, while full power drive is maintained through an associated geartrain at substantially the same overall transmission ratio, thereby facilitating substantially stepless transition between successive modes. In a second embodiment, the input to a variator is switchable between its drivable elements at the ratio extremities of operation thereof to begin a successive variable mode, while full power drive is maintained through an associated geartrain at substantially the same overall transmission ratio, again facilitating substantially stepless transition between successive modes. A third embodiment provides power input to a variator at its ratio extremities of operation to begin successive variable modes, the input being switchable to another variator at its opposed ratio extremity of operation at substantially the same overall transmission ratio, once again facilitating substantially stepless transition between successive modes. The inventive transmission reduces torque and power loading upon the variator(s) and provides stepless extension of variator ratio spreads.

Dependencies are inferred from the claim text.