ROTATING ELECTRICAL MACHINE
A rotating electrical machine includes a rotor and a stator. The rotor includes a shaft, and a rotor core including a shaft press fit hole and plural magnetic steel sheets. Each magnetic steel sheet includes plural press fit protrusions provided to protrude towards the shaft. The press fit protrusions are in contact with the shaft. Each magnetic steel sheet includes plural guide protrusions provided to protrude towards the shaft. The guide protrusions guide the shaft press fitted into the shaft press fit hole. The magnetic steel sheets are stacked to be shifted in a circumferential direction so that the press fit protrusions and the guide protrusions overlap each other in an axial direction.
1 . A rotating electrical machine comprising:
a rotor; and
a stator provided to oppose the rotor in a radial direction;
the rotor including:
a shaft; and
a rotor core including a shaft press fit hole in which the shaft is configured to be press fitted, and a plurality of magnetic steel sheets stacked in an axial direction of the shaft;
each of the plurality of magnetic steel sheets including:
a plurality of press fit protrusions provided at an inner circumferential portion of the magnetic steel sheet to protrude towards the shaft, the plurality of press fit protrusions being in contact with the shaft press fitted in the shaft press fit hole;
a plurality of guide protrusions provided at the inner circumferential portion of the magnetic steel sheet to protrude towards the shaft with protruding amount which is smaller than protruding amount of the plurality of press fit protrusions, the plurality of guide protrusions guiding the shaft being press fitted into the shaft press fit hole; and
the plurality of magnetic steel sheets including the adjacent magnetic steel sheets which are adjacent to each other in the axial direction of the shaft, the adjacent magnetic steel sheets including the magnetic steel sheet at a first side in the axial direction and the magnetic steel sheet at a second side in the axial direction, the plurality of magnetic steel sheets being stacked to be shifted relative to each other in a circumferential direction so that the press fit protrusions of the magnetic steel sheet at the first side and the guide protrusions of the magnetic steel sheet at the second side overlap each other in the axial direction.
2 . The rotating electrical machine according to claim 1 , wherein
at the plurality of magnetic steel sheets, each of the press fit protrusions and each of the guide protrusions are arranged to alternate with each other in the axial direction of the shaft.
3 . The rotating electrical machine according to claim 1 , wherein the magnetic steel sheet at the first side and the magnetic steel sheet at the second side are stacked to be shifted relative to each other in the circumferential direction so that a center line, in the circumferential direction, of each of the press fit protrusions of the magnetic steel sheet at the first side and a center line, in the circumferential direction, of each of the guide protrusions of the magnetic steel sheet at the second side are aligned with each other along the axial direction of the shaft.
4 . The rotating electrical machine according to claim 1 , wherein a set of plurality of press fit protrusions and a set of plurality of guide protrusions are arranged to be adjacent to each other in the circumferential direction.
5 . The rotating electrical machine according to claim 1 , wherein
an inner diameter between tips of the plurality of press fit protrusions is provided to be smaller than an outer diameter of the shaft before the shaft is press fitted, and
an inner diameter between tips of the plurality of guide protrusions is provided to be larger than the outer diameter of the shaft.
6 . The rotating electrical machine according to claim 1 , wherein a set of plurality of press fit protrusions and a set of plurality of guide protrusions are arranged to be point symmetric with each other with respect to a central point of the shaft when viewed from the first side in the axial direction of the shaft.
7 . The rotating electrical machine according to claim 4 , wherein the set of plurality of press fit protrusions and the set of plurality of guide protrusions are arranged to be adjacent to each other at an equal angular interval along the inner circumferential portion of the magnetic steel sheet.
8 . The rotating electrical machine according to claim 1 , wherein each of the press fit protrusions is formed to include a dimensional tolerance of interference fitting relative to the shaft and each of the guide protrusions is formed to include a dimensional tolerance of loose fitting relative to the shaft.