Compressor

Abstract

A compressor capable of reducing operational noise thereof through the use of a low-speed motor without a deterioration of compressive capability. The compressor comprises a hermetic casing, a compressing unit having a compression chamber to compress a refrigerant, a drive unit taking the form of a low-speed motor having four or more poles and adapted to provide power required to compress the refrigerant, and a charger adapted to increase the amount of the refrigerant to be introduced into the compression chamber.

1 . A compressor comprising: 
 a hermetic casing;    a compressing unit having a compression chamber to compress a refrigerant;    a drive unit taking the form of a low-speed motor having four or more poles and adapted to provide power required to compress the refrigerant; and    a charger adapted to increase the amount of the refrigerant to be introduced into the compression chamber.    
   
   
       2 . The compressor according to  claim 1 , wherein the charger is driven upon receiving a driving force of the drive unit to compress the refrigerant inside the hermetic casing and to deliver the compressed refrigerant to the compression chamber.  
   
   
       3 . The compressor according to  claim 2 , 
 wherein the drive unit includes a stator affixed in the hermetic casing, a rotor located in the stator, and a rotary shaft press fitted in the rotor,    wherein the compressing unit includes a cylinder defining the compression chamber, a piston reciprocately installed in the compression chamber, an eccentric shaft unit formed at one end of the rotary shaft, and a connecting rod to connect the eccentric shaft unit to the piston, and    wherein the charger includes an auxiliary cylinder defining a charger chamber, an auxiliary piston reciprocately installed in the charger chamber, an auxiliary connecting rod to connect the auxiliary piston to the eccentric shaft unit, a suction channel to communicate the interior of the hermetic casing with the charger chamber, and a discharge channel to communicate the charger chamber with the compression chamber.    
   
   
       4 . The compressor according to  claim 3 , wherein the auxiliary piston is configured to reach a top dead point thereof before the piston of the compressing unit reaches a top dead point thereof.  
   
   
       5 . The compressor according to  claim 4 , wherein the auxiliary piston reaches a bottom dead point thereof after the piston reaches the top dead point thereof, and reaches the top dead point thereof after the piston reaches a bottom dead point thereof.  
   
   
       6 . The compressor according to  claim 5 , wherein the suction channel and the discharge channel are provided, respectively, with a suction valve and a discharge valve, opening and closing operations of the suction and discharge valves being exactly opposite to each other.  
   
   
       7 . The compressor according to  claim 1 , wherein the drive unit is a 4-pole motor.  
   
   
       8 . The compressor according to  claim 1 , 
 wherein an oil sump is defined in a lower region of the hermetic casing,    wherein the drive unit includes a stator affixed in the hermetic casing, a rotor located in the stator, and a rotary shaft press fitted in the rotor, the rotary shaft having an oil passage to supply oil to frictional regions of the compressing unit and the rotary shaft, and    wherein an oil pickup member is provided at a lower end of the rotary shaft to communicate an oil sump with the oil passage, and a plate-shaped vane is press fitted in the oil pickup member, the vane having a pair of lower bent portions formed at opposite lower corners thereof to be bent in a rotating direction of the rotary shaft and a pair of upper bent portions formed at opposite upper corners thereof to be bent in an opposite direction of the rotating direction.    
   
   
       9 . The compressor according to  claim 8 , wherein the charger is driven upon receiving a driving force of the drive unit to compress the refrigerant inside the hermetic casing and to deliver the compressed refrigerant to the compression chamber.  
   
   
       10 . The compressor according to  claim 9 , 
 wherein the compressing unit includes a cylinder defining the compression chamber, a piston reciprocately installed in the compression chamber, an eccentric shaft unit formed at one end of the rotary shaft, and a connecting rod to connect the eccentric shaft unit to the piston, and    wherein the charger includes an auxiliary cylinder defining a charger chamber, an auxiliary piston reciprocately installed in the charger chamber, an auxiliary connecting rod to connect the auxiliary piston to the eccentric shaft unit, a suction channel to communicate the interior of the hermetic casing with the charger chamber, and a discharge channel to communicate the charger chamber with the compression chamber.    
   
   
       11 . The compressor according to  claim 10 , wherein the auxiliary piston is configured to reach a top dead point thereof before the piston reaches a top dead point thereof.  
   
   
       12 . The compressor according to  claim 11 , wherein the auxiliary piston reaches the top dead point thereof after the piston reaches a bottom dead point thereof, and reaches a bottom dead point thereof after the piston reaches the top dead point thereof.  
   
   
       13 . The compressor according to  claim 12 , wherein the suction channel and the discharge channel are provided, respectively, with a suction valve and a discharge valve, opening and closing operations of the suction and discharge valves being exactly opposite to each other.  
   
   
       14 . The compressor according to  claim 8 , wherein the drive unit is a 4-pole motor.  
   
   
       15 . The compressor according to  claim 8 , 
 wherein the drive unit is a 4-pole motor, and    wherein the pair of upper bent portions, provided at the upper corners of the vane, have an angle of 45°, and the pair of lower bent portions, provided at the lower corners of the vane, have an angle of 30°.