POWER TRANSMISSION APPARATUS FOR HYBRID ELECTRIC VEHICLE

摘要

Disclosed is a power transmission device for a vehicle. A power transmission device for a vehicle according to an embodiment of the present invention includes: a first input shaft selectively connected to an output side of an internal combustion engine via a first clutch; a second input shaft selectively connected to the output side of the internal combustion engine via a second clutch and arranged in the first input shaft without rotational interference; a motor/generator performing motor and generator functions; and a planetary gear set including first, second, and third rotational elements. The first rotational element is directly connected to the motor/generator. The second rotational element is selectively connected to the second input shaft to be synchronized. The third rotational element is directly connected to the first input shaft. The power transmission device for a vehicle is operated in a variable gear ratio mode transmitting torque by varying a gear ratio with the second rotational element by combining the torque of the internal combustion engine inputted into the third rotational element via the first input shaft and the torque of the motor/generator inputted into the second rotational element by the operation of the first clutch and a fixated gear ratio mode transmitting the torque of the internal combustion engine intact while directly connecting the planetary gear set to the second rotational element by operating the second clutch after connecting the second rotational element to the second input shaft to be synchronized while maintaining the operation of the first clutch in the variable gear ratio mode. The purpose of the present invention is to minimize a power loss.