Induction motor and hermetic compressor

An induction motor comprising:

• a stator having a stator iron core produced by laminating a predetermined number of electromagnetic steel plates which have been punched out into a predetermined form, a plurality of stator slots formed along an inner circumferential edge of the stator iron core, and windings inserted into the stator slots;
• and
• a rotor placed inside of the stator via a gap,
• the rotor including:
• a rotor iron core produced by laminating a predetermined number of electromagnetic steel plates which have been punched out into a predetermined form;
• a plurality of double squirrel-cage rotor slots formed along an outer circumferential edge of the rotor and filled with conductive material;
• and
• three air hole parts provided around a rotating shaft hole of the rotor iron core to which a rotating shaft is fitted and having an opening which is open to the rotating shaft hole,
• wherein an inner diameter part of at least one of end rings which short circuit both edges of the conductive material filled into the double squirrel-cage rotor slots is placed adjacent to the air hole parts, and
• wherein the three air hole parts are placed with an almost equal interval, so that 2α+β<180 degrees, where an angle formed by both edges of one of the air hole parts and a center of the rotor shaft is α, and an angle formed by two edges of a closer side of two adjacent air hole parts and the center of the rotor shaft is β.