Hydromechanical variable speed transmission

Abstract

A hydromechanical variable speed transmission (1) including outer and inner differential gear trains each having a carrier carrying planet pinions meshing with two coaxial side gears, the side gears of the outer differential gear train being ring gears one of which is an input ring gear (11) and the other (52) of which rotatably drives the planet pinion carrier of the inner differential gear train, the side gears of the inner differential gear train respectively rotatably driving two coaxial output shafts which extend axially outwards through the ring gears (11, 52) of the outer differential gear train, the planet pinion carrier (14) of the outer differential gear train rotatably driving a hydraulic motor (2) which is fluidly coupled by a hydraulic circuit to rotatably drive a hydraulic pump (3) having a pump control for changing the displacement of the hydraulic pump (3) in response to rotation thereof, wherein the pump control is fixed from rotation to thereby isolate the input ring gear (11) from torque recirculation.

Dependencies are inferred from the claim text.