Power output apparatus

摘要

When power is output from an engine 50 to a crankshaft 56, a multiplying gear unit 57 attached to the crankshaft 56 increases a revolving speed but decreases a torque and transmits the increased revolving speed and the decreased torque to a rotating shaft 57e. A drive shaft 22 of a vehicle that cruises at a constant speed is generally driven at a higher revolving speed and a smaller torque than a driving point at which the engine 50 is driven with a high efficiency. The multiplying gear unit 57 converts the power output from the engine 50 to a power of high revolving speed and low torque. This structure decreases the amount of electrical energy transmitted between a clutch motor 30 and an assist motor 40 in the process of torque conversion by the clutch motor 30 and the assist motor 40 and thereby reduces an energy loss of both the motors 30 and 40. This effectively reduces the required capacities and size of the clutch motor 30 and the assist motor 40.