Hermetic compressor and refrigeration system

Abstract

As an refrigerating machine oil ( 108 ) that is enclosed in a sealed vessel ( 106 ) along a motor element ( 111 ), and a compression element ( 112 ) driven by the motor element ( 111 ), oil that has as base oil a carboxylic ester compound whose kinematic viscosity is 6 mm 2 /s or less at 40 degrees, and 2 mm 2 /s or less at 100 degrees, and that has one ester group as a chief ingredient is used. Thereby, the extraction force of oligomer contained in an organic material can be suppressed to hold comparatively much oligomer in the oil, and the oligomer can be kept from precipitating, and depositing in a refrigeration system, thereby blocking a refrigerant passage, such as a muffler or piping is suppressed.

1 . A hermetic compressor comprising:
 a sealed vessel that reserves refrigerating machine oil, and houses a motor element, and a compression element driven by the motor element, the compression element compresses a refrigerant that has hydrocarbons as a chief ingredient, and the refrigerating machine oil has as base oil a carboxylic ester compound whose kinematic viscosity is 6 mm 2 /s or less at 40 degrees centigrade, and 2 mm 2 /s or less at 100 degrees centigrade, and is composed of a carboxylic ester compound that has one ester group expressed by Chem. 1 as a chief ingredient.
   —COOR1  [Chem. 1] 
   (In the above Formula, R1 represents hydrocarbon radical)   
   
   
       2 . The hermetic compressor according to  claim 1 ,
 wherein the motor element has a stator provided with an insulator, and the insulator is made of at least one selected from polyesters, polyamideimide, polyamides, polyphenylene sulfide, polyetheretherketone, polyether ketone, and a liquid crystal polymer.   
   
   
       3 . The hermetic compressor according to  claim 1 ,
 wherein the motor element has a stator provided with winding, and the winding is a monolayer coating enameled wire having at least one insulating coating layer selected from a group consisting of polyester imide, polyamideimide ester, polyamideimide, polyimide, polyesters, and polyamides, or a multilayer coating enameled wire having at least two insulating coating layers selected from the group.   
   
   
       4 . The hermetic compressor according to  claim 3 ,
 wherein the winding is at least one of the monolayer coating enameled wire, the multilayer coating enameled wire, and a composite electric wire obtained by combining the monolayer coating enameled wire or multilayer coating enameled wire with fibers or a film.   
   
   
       5 . The hermetic compressor according to  claim 1 ,
 wherein the motor element has a stator provided with a winding, and a binding yarn for fixing the winding to the stator is made of at least one selected from polyesters, polyphenylene sulfide, polybutylene terephthalate, polysulfone, polyetheretherketone, polyamideimide, polyimide, polyamides, and a liquid crystal polymer.   
   
   
       6 . The hermetic compressor according to  claim 3 ,
 wherein the motor element has the stator provided with the winding, and an insulating coating layer having a self-lubricating property is formed on the surface of the winding.   
   
   
       7 . The hermetic compressor according to  claim 1 ,
 wherein the compression element has a muffler, and the muffler is formed of at least one selected from polyesters, polyamideimide, polyamide, polyphenylene sulfide, polyetheretherketone, polyether ketone, and a liquid crystal polymer.   
   
   
       8 . The hermetic compressor according to  claim 1 ,
 wherein the compression element has sliding parts that slides on each other, one of the sliding part is made of an iron-based material.   
   
   
       9 . The hermetic compressor according to  claim 8 ,
 wherein the surface of the sliding part made of an iron-based material is subjected to at least one of phosphate coating, carburizing, ion nitriding, and solid lubricant coating.   
   
   
       10 . The hermetic compressor according to  claim 8 ,
 wherein the iron-based material is a sintered body, and coating that has an iron oxide as a chief ingredient is formed in a surface opening of the sintered body, thereby making a dispersion of a density of a sliding surface layer 2% or less.   
   
   
       11 . The hermetic compressor according to  claim 8 ,
 wherein the other sliding part is formed from an aluminum material, and is made to have a hardness of HRB 78 or more.   
   
   
       12 . The hermetic compressor according to  claim 1 ,
 wherein the refrigerating machine oil contains an acid scavenger.   
   
   
       13 . The hermetic compressor according to  claim 1 ,
 wherein the refrigerating machine oil contains an antioxidant.   
   
   
       14 . The hermetic compressor according to  claim 1 ,
 wherein the refrigerating machine oil contains an extreme-pressure additive.   
   
   
       15 . A refrigeration system comprising:
 the hermetic compressor according to  claim 1 ,   and an evaporator, a condenser, and an expansion mechanism.