Hermetic type compressor and refrigeration cycle apparatus

Abstract

As a hermetic type compressor, a motor portion and a compression mechanism portion that are coupled to the motor portion with a rotating shaft interposed therebetween are accommodated in a closed vessel. The compression mechanism portion comprises a cylinder that comprises an internal diameter hole, and a main bearing and a sub-bearing in which a bearing hole that journals the rotating shaft is provided and the internal diameter hole of the cylinder is closed to form a compression chamber in the compression mechanism portion. The main bearing and the sub-bearing have a circular groove that is opened toward the compression chamber side, an inner circumferential surface of the circular groove is tapered such that a diameter increases gradually from the compression chamber side toward an opposite side of the compression chamber side, and a depth of the circular groove is set to 40% of a diameter of the bearing hole.

1 . A hermetic type compressor in which a motor portion and a compression mechanism portion that are coupled to the motor portion with a rotating shaft interposed therebetween are accommodated in a closed vessel,
 wherein the compression mechanism portion comprises:   a cylinder that comprises an internal diameter hole; and   a main bearing and a sub-bearing, in which a bearing hole that journals the rotating shaft is provided and the internal diameter hole of the cylinder is closed to form a compression chamber in the compression mechanism portion,   at least one of the main bearing and the sub-bearing has a circular groove that is opened toward the compression chamber side,   an inner circumferential surface of the circular groove is tapered such that a diameter increases gradually from the compression chamber side toward an opposite side of the compression chamber side, and   a depth L of the circular groove is set to at least 40% of a diameter D of the bearing hole.   
     
     
         2 . The hermetic type compressor according to  claim 1 , wherein, in the main bearing or sub-bearing that comprises the circular groove, a minimum wall thickness b between an inner circumferential surface of the circular groove and a circumferential surface of the bearing hole is set so as to satisfy a relationship of an equation (1):
   0.09×diameter  D  of bearing hole≧minimum wall thickness  b≧ 0.04×diameter  D  of bearing hole   (1).
   
     
     
         3 . The hermetic type compressor according to  claim 1 , wherein a compression chamber of the compression mechanism portion accommodates an eccentric portion that is eccentrically provided while integrated with the rotating shaft and a rolling piston that is fitted in the eccentric portion to rotate eccentrically in the compression chamber in association with rotation of the rotating shaft, and
 assuming that e is an eccentric amount of the eccentric portion and r is an outer circumferential radius of the rolling piston, an outer circumferential radius g of the circular groove satisfies relationships of equations (2) and (3):
   0.5 mm≦[outer circumferential radius  r  (mm) of rolling piston−eccentric amount  e  (mm) of eccentric portion]−outer circumferential radius  g  (mm) of circular groove   (2)
 
   outer circumferential radius  g  (mm) of circular groove>diameter  D  (mm) of bearing hole/2+minimum wall thickness  b  (mm)   (3).
 
   
     
     
         4 . The hermetic type compressor according to  claim 1 , wherein the main bearing and the sub-bearing have a flange whose wall thickness is set to a depth L of the circular groove or less. 
     
     
         5 . A refrigeration cycle apparatus comprising:
 the hermetic type compressor according to  claim 1 ;   a condenser;   an expansion device; and   an evaporator.