Patent ID: 7866957

Claim:
A hermetic compressor comprising: a hermetic container; a motor element accommodated in the hermetic container; and a compressing element that is accommodated in the hermetic container and driven by the motor element, wherein the compressing element has a shaft including an eccentric shaft and a main shaft, and a main bearing for pivoting the main shaft, the motor element is a bipolar permanent magnet motor that has a stator including a stator core and a rotor including a rotor core, the rotor core defines a hollow bore and a through hole, the hollow bore extending from a first axial end of the rotor core, the first axial end on the compressing element side of the rotor core, the through hole extending from the first axial end of the rotor core to a second axial end of the rotor core, the hollow bore having a diameter larger than a diameter of the through hole, the rotor core includes a built-in permanent magnet, an axial length of the permanent magnet being less than an axial length of the rotor core, the permanent magnet being positioned in the rotor core so that it extends from the second axial end of the rotor core opposite the hollow bore, an axial length of the hollow bore is at least ⅓ of the axial length of the rotor core, the main bearing is made of magnetic material, the main bearing extends substantially to a bottom of the hollow bore such that the rotor core is rotatable with respect to the main bearing, and a clearance between an inner surface of the hollow bore and an outer peripheral surface of the main bearing is 0.5 to 3 mm.