ROTOR AND ROTATING ELECTRIC MACHINE

Abstract

A rotor includes: a rotor core including a plurality of core sheets that are laminated together and having a plurality of magnet-receiving holes formed in a folded shape; and a plurality of permanent magnets embedded respectively in the magnet-receiving holes. Each of the core sheets has a plurality of first through-holes and a plurality of second through-holes. Each of the first through-holes has a connection portion formed at an intermediate position in the folded shape of a corresponding one of the magnet-receiving holes to connect inner peripheral edges of the first through-hole that face each other in a width direction of the first through-hole. Each of the second through-holes has no connection portion. The core sheets are identical in configuration to each other. The core sheets are laminated so that each of the magnet-receiving holes is constituted of a mixture of the first and second through-holes of the core sheets.

Description

Claims

1. A rotor comprising: a rotor core including a plurality of core sheets that are laminated together and having a plurality of magnet-receiving holes formed in a folded shape that is convex radially inward; anda plurality of permanent magnets embedded respectively in the magnet-receiving holes of the rotor core, wherein: each of the plurality of core sheets has a plurality of first through-holes and a plurality of second through-holes, each of the first through-holes having a connection portion formed at an intermediate position in the folded shape of a corresponding one of the magnet-receiving holes to connect inner peripheral edges of the first through-hole that face each other in a width direction of the first through-hole, each of the second through-holes having no connection portion;the plurality of core sheets are identical in configuration to each other;the plurality of core sheets are laminated so that each of the magnet-receiving holes of the rotor core is constituted of a mixture of the first and second through-holes of the plurality of core sheets; andeach of the plurality of permanent magnets is a bonded magnet.

2. The rotor as set forth in claim 1, wherein in each of the plurality of core sheets, the first through-holes and the second through-holes are arranged alternately in a circumferential direction.

3. The rotor as set forth in claim 2, wherein every predetermined number of the core sheets are arranged at either a first position or a second position rotated from the first position by an angle corresponding to one of the magnet-receiving holes.

4. The rotor as set forth in claim 3, wherein every one of the core sheets is arranged at either the first position or the second position.

5. The rotor as set forth in claim 1, wherein: each of the first through-holes is formed in a folded shape to have a curved portion; andin each of the first through-holes, the connection portion is located at the curved portion of the first through-hole.

6. The rotor as set forth in claim 1, wherein the connection portion has its width set to be smaller than or equal to a thickness of each of the plurality of core sheets.

7. The rotor as set forth in claim 1, wherein the connection portion has its side edges formed in a uniformly curved shape such that a width of the connection portion decreases toward a central part in an extending direction of the connection portion.

8. The rotor as set forth in claim 1, wherein the rotor core has protruding portions each of which is formed, by protruding a corner portion on one side of one of radially outer ends of the magnet-receiving holes, to reduce a width of the radially outer end.

9. The rotor as set forth in claim 1, wherein the permanent magnets have protruding portions that protrude from axial end faces of the rotor core.

10. The rotor as set forth in claim 1, wherein: each of the permanent magnets is formed in a folded shape to have a curved portion; anda thickness of the curved portion is smaller than a thickness of other portions of the permanent magnet.

11. The rotor as set forth in claim 1, wherein: interior surfaces of the magnet-receiving holes have irregular portions each of which is formed by a difference in position between peripheral edges of the first and second through-holes that overlap in an axial direction; andthe permanent magnets have engaging portions located respectively in recesses of the irregular portions.

12. The rotor as set forth in claim 1, wherein in each of the plurality of core sheets, on a radially outer side of each of the first and second through-holes, there are formed two radially-outer connection portions.

13. A rotating electric machine comprising: a rotor that comprises a rotor core including a plurality of core sheets that are laminated together and having a plurality of magnet-receiving holes formed in a folded shape that is convex radially inward, anda plurality of permanent magnets embedded respectively in the magnet-receiving holes of the rotor core; anda stator configured to apply a rotating magnetic field to the rotor, wherein: each of the plurality of core sheets has a plurality of first through-holes and a plurality of second through-holes, each of the first through-holes having a connection portion formed at an intermediate position in the folded shape of a corresponding one of the magnet-receiving holes to connect inner peripheral edges of the first through-hole that face each other in a width direction of the first through-hole, each of the second through-holes having no connection portion;the plurality of core sheets are identical in configuration to each other;the plurality of core sheets are laminated so that each of the magnet-receiving holes of the rotor core is constituted of a mixture of the first and second through-holes of the plurality of core sheets; andeach of the plurality of permanent magnets is a bonded magnet.