Hybrid electric vehicle powertrain with an enhanced all-electric drive mode

摘要

A hybrid electric vehicle powertrain is disclosed. A gearing assembly mechanically couples an engine, an electric motor and an electric generator. During all-electric drive using the motor as a power source with the engine off, a clutch in the gearing assembly isolates elements of the gearing assembly from a power delivery path to vehicle traction wheels. A clutch may be used also to provide smooth engine starting torque when the generator acts as an engine starter motor.