Gas compressor

Abstract

Compression chambers adjacent to each other in the axial direction of the rotors are communicated with each other. Therefore, a volume of air flowing and leaking from the chamber on the high pressure side into the chamber on the low pressure side is increased as compared with a case of no groove. Otherwise, a volume of air leaking from the chamber on the low pressure side into the chamber on the further lower pressure side than this chamber on the low pressure side is equal to that of the case of no groove. Therefore, the pressure in the chamber on the low pressure side becomes higher than that of the case of no groove. Accordingly, as the inner compression pressure can be enhanced, a difference between the discharge pressure and the inner compression pressure can be reduced. Therefore, a pulsation noise caused by the discharge pulsation can be reduced.

1 . A gas compressor having a compressing mechanism ( 1 ,  2 ) for compressing gas by operating movable members ( 1 ,  2 ) in a housing ( 7 ), comprising: 
 a communicating passage ( 41 ) for communicating between a plurality of compression chambers ( 10   a ,  10   b ) formed by the housing ( 7 ) and the movable members ( 1 ,  2 ).    
   
   
       2 . A gas compressor according to  claim 1 , wherein the compressor mechanism is a screw type compressing mechanism including a pair of screw-shaped rotors ( 1 ,  2 ), which are meshed with each other, provided as the movable members.  
   
   
       3 . A gas compressor according to  claim 2 , wherein the communicating passage is composed when a groove portion ( 41 ) is formed on an inner circumferential face, which is formed in the housing ( 7 ), facing the movable members ( 1 ,  2 ).  
   
   
       4 . A gas compressor according to  claim 3 , wherein the groove portion ( 41 ) is provided on a circumferential curved face ( 7   a ) on the inner circumferential face of the housing ( 7 ).  
   
   
       5 . A gas compressor according to  claim 3 , wherein a cross sectional shape of the communicating passage ( 41 ) is substantially triangular.  
   
   
       6 . A gas compressor according to  claim 3 , wherein the groove portion ( 41 ) composing the communicating passage extends substantially in parallel with the axial direction of the movable members ( 1 ,  2 ).  
   
   
       7 . A gas compressor according to  claim 3 , wherein the groove portion ( 41 ) composing the communicating passage is formed at a position on an inner wall opposing to a suction port ( 35 ) provided on the inner wall of the housing ( 7 ).  
   
   
       8 . A gas compressor according to  claim 3 , wherein a length in the axial direction of the groove portion ( 41 ) composing the communicating passage is not more than a pitch size of the rotors ( 1 ,  2 ) composing the movable member.  
   
   
       9 . A gas compressor according to  claim 3 , wherein the communicating passage ( 41 ) communicates between the adjoining compression chambers ( 10   a ,  10   b ).