Reciprocating compressor for compressing refrigerant

Abstract

A reciprocating compressor includes a driving unit ( 10 ) disposed inside a hermetic container ( 86 ) and generating a reciprocal motional force, a compression unit ( 10 ) for performing a compressing operation on a refrigerant upon receiving the reciprocal motional force generated from the driving unit ( 8 ); and a lubrication unit ( 12 ) for supplying a lubricant to each motional portion of the driving unit ( 8 ) and the compression unit ( 10 ) to perform a lubrication operation. Hydrocarbon consisting of carbon and hydrogen, a sort of natural refrigerant, is used as the refrigerant. The lubricant is a paraffin-based mineral lubricant, which is a sort of mineral oil and well harmonized with the natural refrigerant used for a refrigerator. Accordingly, a lubricating performance is improved and thus a performance of the reciprocating compressor can be enhanced.

1 . A reciprocating compressor for compressing a refrigerant comprising: 
 a hermetic container to which a suction pipe and a discharge pipe are connected;    a driving unit having a stator fixed inside the hermetic container and a mover disposed spaced apart from the stator and linearly and reciprocally moved according to an interaction with the stator;    an organic compound refrigerant sucked into the suction pipe, having an combustibility and explosiveness and consisting of only carbon and hydrogen;    a compression unit for receiving a reciprocal motional force of the driving unit and making a compression operation on the organic compound refrigerant; and    a mineral-based lubricant filled at a lower portion of the hermetic container; and a lubrication unit for supplying the mineral-based lubricant to each motional portion of the driving unit and the compression unit and performing a lubricating operation    
   
   
       2 . The reciprocating compressor of  claim 1 , wherein the stator comprises: 
 an outer stator fixed at the hermetic container;    an inner stator disposed with a certain air gap with an inner circumferential surface of the outer stator; and    a winding coil wound at one of the outer stator and the inner stator, to which power is applied from an external source, and    the mover comprises:    magnets disposed at regular intervals between the outer stator and the inner stator and being linearly and reciprocally moved when power is applied to the winding coil; and    a magnet frame having the magnets mounted thereon and transmitting a linear and reciprocal motional force to the compression unit.    
   
   
       3 . The reciprocating compressor of  claim 1 , wherein the compression unit comprises: 
 a piston connected to the mover and linearly and reciprocally moved;    a cylinder, into which the piston is slidably inserted, for forming a certain compression chamber;    a suction valve mounted at a refrigerant passage formed at the piston and preventing a backflow of the refrigerant after being introduced into the compression chamber; and    a discharge valve mounted at the front side of the cylinder and performing an opening and closing operation on the compressed refrigerant.    
   
   
       4 . The reciprocating compressor of  claim 1 , wherein the lubrication unit comprises: 
 a lubricant pumping unit for pumping the lubricant filled as much as a certain amount at a lower portion of the hermetic container; and    a lubricant supply passage for supplying the lubricant pumped by the lubricant pumping unit to a frictional portion between the piston and the cylinder.    
   
   
       5 . The reciprocating compressor of  claim 1 , wherein the refrigerant is isobutane (R600a) which is hydrocarbon-based and has a molecular formula of CH(CH 3 ) 3 .  
   
   
       6 . The reciprocating compressor of  claim 1 , wherein the lubricant is a paraffin-based lubricant.  
   
   
       7 . The reciprocating compressor of  claim 1 , wherein the lubricant has a density of 0.866˜0.880 g/cm 3  at a temperature of 15° C. and a flash point of above 140° C.  
   
   
       8 . The reciprocating compressor of  claim 1 , wherein the lubricant has a kinematic viscosity of 7.2˜21.8 mm 2 /s at a temperature of 40° C. and a viscosity index of 73˜99.  
   
   
       9 . The reciprocating compressor of  claim 1 , wherein the lubricant has a flow point of below −25° C. and a total acid number of below 0.01 mgKOH/g.  
   
   
       10 . The reciprocating compressor of  claim 1 , wherein the lubricant has a water content of below 20 ppm and a breakdown voltage of above 30 kV.