Motor rotor, motor using same, and electric compressor

A motor rotor, comprising:

• a cylindrical rotor core which is formed by stacking a plurality of electromagnetic steel plates;
• end plates and balance weights which are stacked on both ends of the rotor core;
• and
• a plurality of headed swaging pins which penetrate and integrally fasten the rotor core, the end plates, and the balance weights,
• wherein a washer or a spacer which is formed of a harder material than materials of the swaging pins is interposed between a head of each swaging pin and a seating surface of each balance weight, and
• wherein the washer or the balance weight is not interposed between a swaging portion of the swaging pin and the end plate or the balance weight and a swaging piece of the swaging portion can be bitten to the end plate or the balance weight.