Squirrel-cage rotor and manufacturing method of squirrel-cage rotor

A manufacturing method of a squirrel-cage rotor, comprising:

• forming a rotor assembly by disposing a pair of end rings at opposite sides in a rotational axis direction of a rotor core provided with a plurality of circumferentially disposed slot holes opened along the rotational axis direction of the rotor, each of the pair of end rings being prepared by laminating a plurality of sheet members and being provided with a plurality of circumferentially disposed through holes opened corresponding to the plurality of slot holes, with a brazing filler metal sandwiched between adjacent sheet members, and respectively inserting a plurality of bar elements through the plurality of slot holes and the plurality of through holes;
• heating the rotor assembly;
• and
• applying a compressive force on opposite sides of the pair of end rings, during heating the rotor assembly, so that the brazing filler metal sandwiched between the adjacent sheet members melts and flows into clearances between the plurality of bar elements and the plurality of through holes to braze the plurality of bar elements and the pair of end rings through the brazing filler metal.