Electric machine e.g. electric motor has rotor with recessed portions that are enlarged by supplementary cutting processing in green compact state of rotor, where thickness between rotor outer periphery and recessed portion is made small

摘要

The electric machine has permanent magnets which are arranged in a rotor (2) made of sintered steel. The rotor comprises recessed portions (10) which are enlarged by a supplementary cutting processing in a green compact state of the rotor. The recessed portion comprises rectangular region (11) and circular regions (12) at the corners of the rectangular regions. The circular regions face the outer periphery (13) of the rotor. The thickness (y) between the outer periphery of rotor and recessed portion is made small. An independent claim is included for method for manufacturing rotor using sintered steel.