Rotating electric machine enabling cooling of a cooling target region

1. A rotating electric machine comprising:

a rotation shaft arranged rotatably;

a rotor having a storing hole capable of storing a permanent magnet, including the permanent magnet stored in said storing hole, and being fixed to said rotation shaft;

a stator facing said rotor and including a coil;

an end plate provided at an axial end of said rotor;

a coolant passage formed in said end plate and running along an axial end of said permanent magnet for allowing a coolant to flow,

said end plate having a discharge hole communicating with said coolant passage and capable of discharging said coolant,

a cooling target region including said permanent magnet being defined at a portion of said rotor located at an outer circumferential side of said rotor with respect to a radially inner end of said permanent magnet,

said discharge hole being located at a radially inner side of said rotor with respect to said cooling target region, and

said coolant passage includes a first flow passage and a second flow passage, said first flow passage formed by the axial end of the rotor and the end plate, extending in a radial direction of said rotor, said coolant passage reaching said cooling target region and being formed such that a width of said rotor in a circumferential direction increases toward a radially outer side of said rotor, and said second flow passage formed by the end plate, connected to said first flow passage and extending from a connection point with the first flow passage to the radially inner side of said rotor to reach said discharge hole.

2. The rotating electric machine according to claim 1 , further comprising a supply channel formed in said rotation shaft and capable of supplying said coolant to said coolant passage, wherein

said first flow passage communicating with said supply channel and running along an axial end face of said permanent magnet.

3. The rotating electric machine according to claim 2 , wherein said discharge hole is located at a rearward side in a rotation direction of said rotor with respect to the connection point between said coolant passage and said supply channel.

4. The rotating electric machine according to claim 1 , wherein said discharge hole extends toward a radially outer side of said rotor while running from said coolant passage in an axial direction of said rotation shaft.

5. The rotating electric machine according to claim 1 , further comprising a projection formed at a portion, in an axial end face of said end plate, adjacent to an opening of said discharge hole at a radially outer side of said rotor and protruding in an axial direction of said rotation shaft with respect to the end face of said end plate.

6. The rotating electric machine according to claim 5 , wherein an axial end of said projection is located at an axially outer side of said rotor with respect to an axial end of said coil.

7. The rotating electric machine according to claim 1 , wherein said first flow passage is formed to run along an entire surface of the axial end face of said permanent magnet.

8. The rotating electric machine according to claim 1 , further comprising a supply channel capable of supplying said coolant to said coolant passage, said supply channel including a radial passage extending in the radial direction toward the permanent magnet and connected to said coolant passage.