Refrigerant compressor

Abstract

A refrigerant compressor includes a hermetic container storing refrigerant oil an electrically-driven element and a compressing element driven by the electrically-driven element. The compressing element includes a cylinder block having a cylindrical compression chamber and a cylindrical piston reciprocating in the compression chamber. The compression chamber and the piston have a diameter difference in the range of not shorter than 4 μm to not longer than 15 μm. The refrigerant oil has viscosity of 8 mm 2 /s or less at 40° C. and is prepared by mixing a first refrigerant oil having viscosity of less than 8 mm 2 /s at 40° C. with a second refrigerant oil having viscosity of 20 mm 2 /s or more at 40° C.

1 . A refrigerant compressor comprising:
 a hermetic container storing refrigerant oil;   an electrically-driven element; and   a compressing element driven by the electrically-driven element, the compressing element including a cylinder block having a cylindrical compression chamber and a cylindrical piston reciprocating in the compression chamber, wherein   the compression chamber and the piston have a diameter difference in a range of not shorter than 4 μm to not longer than 15 μm, and   the refrigerant oil has viscosity of not more than 8 mm 2 /s at 40° C. and is prepared by mixing a first refrigerant oil having viscosity of less than 8 mm 2 /s at 40° C. with a second refrigerant oil having viscosity of not less than 20 mm 2 /s at 40° C.   
     
     
         2 . The refrigerant compressor of  claim 1 , wherein
 the refrigerant oil contains the second refrigerant oil of not less than 3 wt %.   
     
     
         3 . The refrigerant compressor of  claim 1 , wherein
 a refrigerant to be compressed in the compression chamber is one of an HFC refrigerant and an HC refrigerant, and   the refrigerant oil contains one of ester oil, mineral oil, and hard alkyl benzene oil as base oil.   
     
     
         4 . The refrigerant compressor of  claim 1 , wherein
 an antioxidant is added to the refrigerant oil.   
     
     
         5 . The refrigerant compressor of  claim 1 , wherein
 an extreme-pressure additive is added to the refrigerant oil.   
     
     
         6 . The refrigerant compressor of  claim 1 , wherein
 an oil agent is added to the refrigerant oil.