US Patent 8689759 Dual drive pump system using an engine starter motor

A dual drive pump system for rear wheel or front wheel drive automatic transmission in a motor vehicle includes a dual drive pump disposed off-axis of the transmission input shaft axis and driven by a gear train driven by a hub. The dual drive pump is also driven by a gear train driven by an engine starter motor. Torque multiplication through the gear train allows the dual drive pump to have a smaller displacement while still providing the hydraulic pressure needs of the transmission. The dual drive pump may be driven by either an engine or the engine starter motor depending on the operating conditions of the motor vehicle.