Vehicle drive device for lubrication a power transmission and cooling a rotating electric machine

1. A vehicle drive device comprising:

a rotating electric machine;

a power transmission mechanism transmitting a rotational drive power between the rotating electric machine and a plurality of wheels;

a casing housing the rotating electric machine and the power transmission mechanism, the vehicle drive device supplying an oil stored in the casing to the power transmission mechanism and the rotating electric machine to lubricate the power transmission mechanism and to cool the rotating electric machine;

a lubricating path including a first oil pump to pump an oil stored in the casing by the first oil pump and to supply the oil to the power transmission mechanism for lubricating the power transmission mechanism;

a cooling path separated from the lubricating path and provided for the rotating electric machine, the cooling path including: (i) a second electric oil pump to pump the oil stored in the casing by the second electric oil pump to supply the oil exclusively to the rotating electric machine for cooling the rotating electric machine, (ii) an oil cooler cooling the oil to be supplied to the rotating electric machine, and (iii) a cooling pipe, which is located downstream of the oil cooler and is arranged vertically above the rotating electric machine in a housing space of the casing, into which at least a portion of the oil discharged from the oil cooler and from the second electric oil pump is introduced, and the cooling pipe includes a first discharge hole and a second discharge hole that discharges the introduced oil to the rotating electric machine; and

a controller configured to control the second electric oil pump to supply oil to the rotating electric machine only when a temperature of a stator core of the rotating electric machine is greater than a predetermined temperature threshold value.

2. The vehicle drive device according to claim 1 , wherein the lubricating path includes a catch tank storing at least a portion of the oil discharged from the first oil pump and ejecting the stored oil to the power transmission mechanism.

3. The vehicle drive device according to claim 1 , further comprising a rotor disposed in the rotating electric machine rotatably supported by a cylindrical rotor shaft penetrating through and integrally fixed to the rotor such that at least a portion of the oil discharged from the second electric oil pump is introduced into an inside of the rotor shaft, wherein

the cooling path includes a radial oil passage formed in the rotor shaft to eject the oil introduced into the inside of the rotor shaft to the rotating electric machine.

4. The vehicle drive device according to according to claim 1 , further comprising a rotor disposed in the rotating electric machine rotatably supported by a cylindrical rotor shaft penetrating through and integrally fixed to the rotor such that at least a portion of the oil discharged from the second electric oil pump is introduced into an inside of the rotor shaft, wherein

the cooling path includes (i) a supply oil passage to supply the oil discharged from the second electric oil pump to an oil introduction port of the cooling pipe, (ii) a branch oil passage branched from the supply oil passage to introduce a portion of the oil supplied to the supply oil passage to the inside of the rotor shaft, and (iii) a radial oil passage formed in the rotor shaft to eject the oil introduced into the inside of the rotor shaft to the rotating electric machine.

5. The vehicle drive device according to claim 4 , further comprising an orifice located between the supply oil passage and the oil introduction port of the cooling pipe such that a cross-sectional area in flow-passage is smaller than in the supply oil passage.