VEHICULAR POWER TRANSMISSION SYSTEM

摘要

To provide a power transmission unit, which is capable of reducing a power loss, and which is downsized to be mounted on a vehicle easily. A power transmission unit according to the present invention comprising: a first prime mover 2; speed change gear pairs 14 to 17; output members 11 and 12; a differential mechanism 1, which has a first rotary element Cr connected with the first prime mover 2, a second rotary element Rg, and a third rotary element Sn selectively outputting the power to the output member, and which is adapted to perform a differential action among those three rotary elements; and a second prime mover 3 connected with the second rotary element; wherein the speed change gear pair includes at lease one pair of first speed change gear pair, which is arranged between the first rotary element and the output member and which is allowed to transmit the torque selectively, and at least one pair of second speed change gear pair which is arranged between the third rotary element and the output member and which is allowed to transmit the torque selectively; and a locking mechanism SL for locking the second prime mover selectively to halt a rotation of the second prime mover.