Compressor

Abstract

A compressor has a valve port plate made of a steel, through which heat of compressed gas having a relatively higher temperature is transmitted to suction gas having a relatively lower temperature. The valve port plate is nitrided or nitrocarburized for reducing heat transmission from the compressed gas to the suction gas.

1 . A compressor comprising: 
 a valve port plate made of a steel, wherein the valve port plate is nitrided or nitrocarburized.    
   
   
       2 . The compressor according to  claim 1 , wherein the valve port plate has a thermal conductivity of about 60 W/mK or less.  
   
   
       3 . The compressor according to  claim 1 , wherein the nitriding or nitrocarburizing is selected from a group comprising salt-bath nitriding, gas nitrocarburizing, gas nitriding and ion nitriding.  
   
   
       4 . The compressor according to  claim 1 , wherein the valve port plate is made of nitriding steel.  
   
   
       5 . The compressor according to  claim 1 , wherein the valve port plate is made of electromagnetic soft iron.  
   
   
       6 . The compressor according to  claim 1 , wherein the valve port plate is made of cold-rolled steel plate.  
   
   
       7 . The compressor according to  claim 1 , wherein the valve port plate is made of hot-rolled mild steel plate.  
   
   
       8 . The compressor according to  claim 1 , wherein the compressor is of a piston type, further comprising: 
 a cylinder block having formed therethrough a cylinder bore; and    a piston received in the cylinder bore for reciprocation therein, whereby gas is introduced, compressed and discharged.    
   
   
       9 . The compressor according to  claim 8 , wherein the gas is refrigerant gas.  
   
   
       10 . The compressor according to  claim 8 , further comprising: 
 a housing having formed therein a suction chamber and a discharge chamber, wherein the valve port plate is located between the housing and the cylinder block, and wherein a nitride layer is formed on at least one surface of the valve port plate.    
   
   
       11 . The compressor according to  claim 10 , wherein the nitride layer is formed on the surface of the valve port plate adjacent to the housing.  
   
   
       12 . The compressor according to  claim 10 , wherein the nitride layer is formed on the surface of the valve port plate adjacent to the cylinder block.  
   
   
       13 . The compressor according to  claim 10 , wherein the nitride layer is formed on opposite surfaces of the valve port plate.  
   
   
       14 . The compressor according to  claim 10 , wherein the valve port plate has formed therein a diffusion layer of nitrogen contiguously to the nitride layer.  
   
   
       15 . The compressor according to  claim 1 , wherein the valve port plate is salt-bath nitrided or gas nitrocarburized to have a nitride layer having a thickness of about 10 μm or more.  
   
   
       16 . The compressor according to  claim 15 , wherein the nitride layer has a thickness of about 20 μm or more.  
   
   
       17 . The compressor according to  claim 15 , wherein the valve port plate is gas nitrocarburized to have a nitride layer having a thickness of about 50 μm or more.  
   
   
       18 . The compressor according to  claim 1 , wherein carbon dioxide is used as refrigerant for the compressor.