A counter driven gear into which motive power is input from a second electric motor, a counter drive gear that has a smaller diameter than the counter driven gear and drives a differential gear device, and a counter shaft constitute a speed reduction mechanism. This eliminates the need for a ring gear on an outer side of a stepped pinion, and thus prevents an increase in an outside diameter of a first case cover on an engine side that protrudes from a case main body of a transaxle case so as to house the speed reduction mechanism. At least either part of the differential gear device or part of the counter shaft is disposed so as to protrude toward the engine side beyond an interface between the engine and the transaxle case, which can shorten a dimension of the transaxle case in the direction of a second axis.

A drive apparatus for a vehicle, including: an engine; first through third electric motors; a differential mechanism; a first drive shaft for driving front wheels; a second drive shaft for driving rear wheels; and a processor. The differential mechanism includes first through third rotary elements. The engine and the first electric motor are connected to the first rotary element. The second electric motor is connected to the second rotary element. The first drive shaft is connected to the third rotary element. The third electric motor is connected to the second drive shaft. The processor is configured to cause the second electric motor to generate a torque, when performing a series driving in which the first electric motor is operated as an electric generator by operation of the engine, and the third electric motor is operated as a prime mover by an electric power generated by the first electric motor.

In a drive apparatus for a vehicle, a first HEV mode and an all-wheel drive mode can be established. In the first HEV mode, the vehicle is caused to run in front- or rear-wheel drive, by causing a first electric motor to be operated as a generator, while causing a third electric motor to be operated as a prime mover to transmit a torque to a second drive shaft. In the all-wheel drive mode, the vehicle is caused to run in all-wheel drive, by causing an electric power to be transferred between the first and second electric motors, while causing the third electric motor to be operated as the prime mover to transmit the torque to the first and second drive shafts, and the first, second and third electric motors are controlled such that a torque distribution between the first and second drive shafts becomes a required ratio.

A vehicle drive apparatus includes an engine and a first drive unit that includes (i) a first electric motor, (ii) a second electric motor, (iii) a planetary gear device having first through third rotary elements that are rotatable about a first axis, (iv) a first pair of gears consisting of a counter drive gear and a counter driven gear meshing with each other, (v) a counter driven shaft on which the counter driven gear is disposed and (vi) a second pair of gears consisting of a final drive gear and a final driven gear meshing with each other. The counter drive gear, the planetary gear device and the second electric motor are disposed on the first axis, and are arranged in this order of description as viewed in a direction away from the engine. The first electric motor is disposed on a second axis parallel with the first axis.

A transaxle mounted on a vehicle includes a shaft that integrally rotates together with both a coupling gear included in a gear mechanism and a rotor of an electric motor that is spaced apart from the coupling gear in an axial direction; a first oil passage formed in the shaft and configured to guide the oil scooped up by at least one gear included in the gear mechanism and supplied to an end portion of the shaft on the side of the coupling gear to a predetermined cooling target in a case; a second oil passage formed in the shaft and configured to guide the oil supplied from a pump to an end portion of the shaft on the side of the rotor; and a closure disposed in the shaft and configured to guide restrict communication between the first oil passage and the second oil passage.

In a hybrid electric vehicle, (a) an engine and a first electric motor are disposed to be rotatable about a first axis, (b) a second electric motor, a reduction mechanism, and a differential gear are disposed to be rotatable about a second axis parallel with the first axis, (c) the second electric motor, a first planetary gear device, a second planetary gear device, and the differential gear are disposed in order from the first electric motor side to the engine side in the direction of the second axis, and (d) a second rotor shaft, a ring gear of the first planetary gear device, and a carrier of the second planetary gear device are respectively coupled to a sun gear of the first planetary gear device, a sun gear of the second planetary gear device, and the differential gear.

An auxiliary driving apparatus of a 4WD hybrid electric vehicle is a series-type driving apparatus to which a longitudinal engine is applied, and a driving mechanism including an engine, a motor, and a plurality of clutches is applied to the front wheel side of a hybrid electric vehicle with a motor applied to the rear wheel side as a main driving source, so that the series mode can be implemented in the rear wheel 2WD mode, and the 4WD (AWD) EV mode can be driven when the engine is stopped.