Hermetic refrigerant compressor and refrigerator-freezer using the same

Abstract

In a hermetic refrigerant compressor, a thrust bearing (e.g., thrust ball bearing (210)) is provided on a thrust surface (136) of a main bearing (134). One end of a sliding surface of the main bearing (134), the one end being closer to a compression chamber (133) than an opposite end of the sliding surface, is a first end, and the opposite end of the sliding surface is a second end. A distance between a center axis of the compression chamber (133) and the second end of the sliding surface (sliding surface lower end (139)) of the main bearing (134) is a distance L, and a distance between the center axis of the compression chamber (133) and the first end of the sliding surface (sliding surface upper end (138)) of the main bearing (134) is a distance La. When the distance L is in a range of 38 mm to 51 mm, the distance La is less than or equal to 16 mm.

1 . A hermetic refrigerant compressor comprising a sealed container in which lubricating oil is stored, the sealed container accommodating an electric element and a compression element, the compression element being driven by the electric element and configured to compress a refrigerant, wherein
 the compression element includes:
 a crankshaft including a main shaft and an eccentric shaft; 
 a cylinder block including a compression chamber; 
 a piston that is inserted in the compression chamber in a reciprocable manner; 
 a coupler that couples the piston and the eccentric shaft; 
 a main bearing that pivotally supports the main shaft; and 
 a thrust bearing provided on a thrust surface of the main bearing, 
   one end of a sliding surface of the main bearing, the one end being closer to the compression chamber than an opposite end of the sliding surface, is a first end,   the opposite end of the sliding surface is a second end,   a distance between a center axis of the compression chamber and the second end of the sliding surface of the main bearing is a distance L,   a distance between the center axis of the compression chamber and the first end of the sliding surface of the main bearing is a distance La, and   when the distance L is in a range of 38 mm to 51 mm, the distance La is less than or equal to 16 mm.   
     
     
         2 . The hermetic refrigerant compressor according to  claim 1 , wherein
 the thrust bearing includes:
 a lower race positioned on the thrust surface; 
 an upper race positioned facing the lower race; and 
 a plurality of rolling elements that are arranged between the upper and lower races and that are rollably in contact with the upper and lower races, and 
   the rolling elements are balls.   
     
     
         3 . The hermetic refrigerant compressor according to  claim 1 , wherein
 the lubricating oil has a kinematic viscosity in a range of 1 mm 2 /S to 7 mm 2 /S at 40° C.   
     
     
         4 . The hermetic refrigerant compressor according to  claim 3 , wherein
 the lubricating oil has a mass average molecular weight in a range of 150 to 400, and contains 0.5% by mass or more of a high molecular weight component, and   the high molecular weight component has a mass molecular weight of greater than or equal to 500.   
     
     
         5 . The hermetic refrigerant compressor according to  claim 1 , wherein
 the lubricating oil contains an oiliness agent.   
     
     
         6 . The hermetic refrigerant compressor according to  claim 5 , wherein
 the oiliness agent is an ester-based compound.   
     
     
         7 . The hermetic refrigerant compressor according to  claim 1 , wherein
 a distillation fraction of the lubricating oil at a distillation temperature of 300° C. is 0.1% or greater, and a distillation end point is 440° C. or higher.   
     
     
         8 . The hermetic refrigerant compressor according to  claim 1 , wherein
 the lubricating oil contains a sliding modifier such that a content of the sliding modifier in the lubricating oil in terms of an atomic weight of sulfur is greater than or equal to 100 ppm.   
     
     
         9 . The hermetic refrigerant compressor according to  claim 1 , wherein
 the lubricating oil contains a phosphorus-based extreme-pressure additive.   
     
     
         10 . The hermetic refrigerant compressor according to  claim 1 , wherein
 the lubricating oil is at least one selected from the group consisting of mineral oil, alkyl benzene oil, and ester oil.   
     
     
         11 . The hermetic refrigerant compressor according to  claim 1 , wherein
 the electric element is inverter-driven at a plurality of operating frequencies.   
     
     
         12 . The hermetic refrigerant compressor according to  claim 11 , wherein
 the hermetic refrigerant compressor is operated at a rotation speed of 35 rps or less.   
     
     
         13 . A refrigerator-freezer comprising a refrigerant circuit including:
 the hermetic refrigerant compressor according to  claim 1 ;   a radiator;   a decompressor; and   a heat absorber, wherein   in the refrigerant circuit, the hermetic refrigerant compressor, the radiator, the decompressor, and the heat absorber are connected by piping in an annular manner.