Rotor having magnets secured with plates and insulation in magnet holes

1. A rotor comprising:

a rotor core that is formed by stacking a plurality of steel plates each of which has an opening;

a magnet that is inserted in a magnet hole formed by disposing the openings such that the openings overlap each other; and

a magnetic plate that is disposed between an inner wall defining the magnet hole and the magnet so as to prevent contact between the inner wall defining the magnet hole and the magnet, wherein

at least a contact portion of the magnetic plate is subjected to an insulating process, the contact portion of the magnetic plate contacting the magnet.

2. The rotor according to claim 1 , wherein at least a surface of the magnet has electrical conductivity.

3. The rotor according to claim 1 , wherein the magnetic plate is joined to the magnet.

4. The rotor according to claim 3 , wherein the magnet includes a plurality of small magnets combined with each other, and the plurality of small magnets are joined to the magnetic plate.

5. The rotor according to claim 3 , wherein:

the magnetic plate that is disposed on a surface of the magnet includes a plurality of small magnetic plates, the surface extending in a surface plane, the plurality of small magnetic plates disposed such that the plurality of small magnetic plates do not overlap each other when viewed in a direction perpendicular to the surface plane; and

the plurality of small magnetic plates are joined to the magnet.

6. The rotor according to claim 1 , wherein:

each of the magnet and the magnet hole has a rectangular parallelepiped shape; and

the magnetic plate that is disposed on a surface of the magnet extends outward from a width of the magnet.