Rotating electric machine
A rotor core of a rotating electric machine includes a cooling passage. The cooling passage includes an upstream end that opens in a first end surface of the rotor core and a downstream end that opens in a second end surface of the rotor core. The rotating electric machine is further equipped with a rectifying structure for converting the flow direction of gas an axial direction and a circumferential direction of the rotor. The rectifying structure is fixed to a non-rotating portion in a casing so as to face a rotor in an axial direction.
1. A rotating electric machine comprising: a shaft; a rotor fixed to the shaft; a stator surrounding the rotor; and a casing accommodating the rotor and the stator, the rotating electric machine being configured to cool a part to be cooled, by a gas flowing in the casing,
wherein the rotor includes a rotor core supported by the shaft,
the rotor core includes a cooling passage configured to allow communication between a first end surface which is one end surface of the rotor core in an axial direction of the rotor core to a second end surface which is another end surface of the rotor core, the gas flowing through the cooling passage,
the cooling passage includes an upstream end that opens in the first end surface and a downstream end that opens in the second end surface,
the rotating electric machine further comprises a rectifying structure configured to convert a flow direction of the gas between the axial direction and a circumferential direction of the rotor, and
the rectifying structure is fixed to a non-rotating portion in the casing so as to face the rotor in the axial direction.
2. The rotating electric machine according to claim 1 , wherein the rectifying structure includes an inlet-side rectifying member facing the upstream end of the cooling passage, and
the inlet-side rectifying member includes a plurality of inlet-side fins configured to convert the flow direction from the axial direction into the circumferential direction.
3. The rotating electric machine according to claim 2 , wherein the shaft is rotatably supported by a first bearing disposed on one end side of the casing and a second bearing disposed on another end side of the casing,
the first end surface of the rotor core is disposed between the first bearing and the second end surface,
the second end surface of the rotor core is disposed between the second bearing and the first end surface, and
the inlet-side rectifying member is disposed between the first bearing and the first end surface.
4. The rotating electric machine according to claim 2 , wherein the rotor includes a retaining member disposed on the first end surface of the rotor core,
the retaining member includes an inlet-side through hole communicating with the cooling passage, and the inlet-side through hole is inclined with respect to an axis of the rotor, and
a length of each of the plurality of inlet-side fins in a radial direction is set in a manner so that the plurality of inlet-side fins face the inlet-side through hole in the axial direction.
5. The rotating electric machine according to claim 1 , wherein the rectifying structure includes an outlet-side rectifying member facing the downstream end of the cooling passage, and
the outlet-side rectifying member includes a plurality of outlet-side fins configured to convert the flow direction from the circumferential direction into the axial direction.
6. The rotating electric machine according to claim 5 , wherein the shaft is rotatably supported by a first bearing disposed on one end side of the casing and a second bearing disposed on another end side of the casing,
the first end surface of the rotor core is disposed between the first bearing and the second end surface,
the second end surface of the rotor core is disposed between the second bearing and the first end surface, and
the outlet-side rectifying member is disposed between the second bearing and the second end surface.
7. The rotating electric machine according to claim 5 , wherein the rotor includes a retaining member disposed on the second end surface of the rotor core,
the retaining member includes an outlet-side through hole communicating with the cooling passage, and the outlet-side through hole is inclined with respect to an axis of the rotor, and
a length of each of the plurality of outlet-side fins in a radial direction is set in a manner so that the plurality of outlet-side fins face the outlet-side through hole in the axial direction.
8. The rotating electric machine according to claim 1 , wherein the rectifying structure includes an inlet-side rectifying member facing the upstream end of the cooling passage and an outlet-side rectifying member facing the downstream end of the cooling passage,
the inlet-side rectifying member includes a plurality of inlet-side fins configured to convert the flow direction from the axial direction into the circumferential direction, and
the outlet-side rectifying member includes a plurality of outlet-side fins configured to convert the flow direction from the circumferential direction into the axial direction.
9. The rotating electric machine according to claim 8 , wherein the rotor includes a first retaining member disposed on the first end surface of the rotor core, and a second retaining member disposed on the second end surface of the rotor core,
the first retaining member includes an inlet-side through hole communicating with the cooling passage, and the inlet-side through hole is inclined with respect to an axis of the rotor,
the second retaining member includes an outlet-side through hole communicating with the cooling passage, and the outlet-side through hole is inclined with respect to the axis of the rotor,
a length of each of the plurality of inlet-side fins in a radial direction is set in a manner so that the plurality of inlet-side fins face the inlet-side through hole in the axial direction,
a length of each of the plurality of outlet-side fins in the radial direction is set in a manner so that the plurality of outlet-side fins face the outlet-side through hole in the axial direction,
a shortest distance in the radial direction between the inlet-side through hole and a central axis of the shaft, and a shortest distance in the radial direction between the outlet-side through hole and the central axis are different, and
a length of each of the plurality of inlet-side fins in the radial direction and a length of each of the plurality of outlet-side fins in the radial direction are different.
10. The rotating electric machine according to claim 1 , wherein the non-rotating portion is the stator, and
the rectifying structure is fixed to an inner circumferential surface of the stator.
11. The rotating electric machine according to claim 10 , wherein the stator includes a stator core, a coil end portion projecting from the stator core in the axial direction, and a mold portion having an annular shape and covering the coil end portion, and
the rectifying structure is fitted to an inner circumferential surface of the mold portion.