Hybrid powertrain with torque-multiplying engine starting mechanism and method of controlling a hybrid powertrain

A hybrid powertrain comprising:

• an engine with an engine output member;
• a transmission with a transmission input member;
• a motor/generator configured to apply torque to the transmission input member;
• a hydraulically-actuated friction plate clutch selectively engagable to connect the engine output member for common rotation with the transmission input member;
• an active material clutch having a first portion connected with the transmission input member via a first gear train and a second portion connected with the engine output member via a second gear train, and selectively engagable to transfer torque from the transmission input member to the engine output member with torque multiplication;
• wherein the first gear train includes a first gear connected for rotation the transmission input member and a second gear connected for rotation with the first portion of the active material clutch;
• wherein the second gear train includes a spur gear connected for rotation with the second portion of the second clutch and meshing with a ring gear connected for rotation with the engine output member;
• wherein the gear ratio of the ring gear to the spur gear is greater than the gear ratio of the second gear to the first gear.