Drive unit for a hybrid vehicle

A drive unit for a hybrid vehicle in which a prime mover is comprised of an engine, a first motor and a second motor, comprising:

• a first differential mechanism comprised of a first input element, a first reaction element and a first output element;
• a second differential mechanism comprised of a second input element, a second reaction element and a second output element;
• and
• a first clutch device that is adapted to connect the engine selectively with the first input element;
• wherein the first motor is connected with the first reaction element, the second motor is connected with the second input element, and the first output element and the second output element are individually connected with an output member;
• and
• wherein a drive mode includes a first hybrid mode where the vehicle is propelled in a forward direction by an output torque of the engine and an output torque of the second motor;
• wherein the drive unit further comprises a second clutch device that is adapted to connect the first input element selectively with the second input element;
• and
• wherein the drive mode includes a reverse stage fixing mode where the vehicle is propelled in a backward direction by at least the output torque of the engine while changing a rotational speed of the output member in accordance with a speed of the engine.