Patent ID: 7748483

Claim:
An accessory drive system for a hybrid electric vehicle comprising: an engine including a plurality of intake valves, a plurality of exhaust valves, and a crankshaft; a motor/generator independently connectable to a transmission; a selectively engageable torque transmitting device disposed between the engine and the transmission, wherein said torque transmitting device is disengageable to de-couple the engine and the motor/generator from the transmission; a drive pulley connected to the engine; a driven pulley connected to an accessory; a drive belt operatively connecting said drive pulley and said driven pulley and operable to transfer drive forces between said drive pulley and said driven pulley; a controller operatively connected to the torque-transmitting device, the engine and the motor/generator, said controller configured to control the torque-transmitting device, the engine and the motor/generator to ensure that the accessory is sufficiently powered to remain fully operational by the engine when the engine is running or by said motor/generator when the engine is not running; and wherein the controller is configurable to manipulate the intake valves and the exhaust valves when the accessory is being driven by power from the motor/generator through the engine crankshaft, in order to reduce crankshaft rotational resistance and engine pumping losses, and thereby improve the efficiency of the accessory drive system.