Gear driven compressor with vent compressor

Abstract

A two-stage compressor includes an auxiliary compressor that reduces the pressure of the gear section. The auxiliary compressor intake communicates with the gear section and the discharge of the compressor communicates with the inlet to the second stage of the compressor.

What is claimed is:  
     
         1 . A two-stage compressor comprising: 
 a compressor housing;    a first stage compressor section within the compressor housing having a first inlet and a first discharge;    a second stage compressor section within the compressor housing having a second inlet and a second discharge, wherein the first discharge section is in communication with the second inlet;    a gear section within the compressor housing; and    an auxiliary compressor in communication with the gear section and the second inlet.    
     
     
         2 . The compressor of  claim 1 , wherein the compressor is a centrifugal compressor.  
     
     
         3 . The compressor of  claim 1 , wherein the compressor is a refrigerant compressor.  
     
     
         4 . The compressor of  claim 1 , wherein the auxiliary compressor is a hermetic compressor.  
     
     
         5 . The compressor of  claim 1 , wherein the auxiliary compressor is a reciprocating compressor.  
     
     
         6 . The compressor of  claim 1 , wherein the auxiliary compressor is a scroll compressor.  
     
     
         7 . A method of starting a two-stage compressor having a compressor housing, a first stage compressor within the compressor housing having a first inlet and a first discharge section, a second stage compressor within the compressor housing having a second inlet and a second discharge section, wherein the first discharge section is in communication with the second inlet, a gear section within the compressor housing and an auxiliary compressor in communication with the gear section and the second inlet, the method comprising the steps of: 
 operating the auxiliary compressor for a period of time; and    starting the two-stage compressor.    
     
     
         8 . A method of operating a two-stage compressor having a compressor housing, a first stage compressor within the compressor housing having a first inlet and a first discharge section, a second stage compressor within the compressor housing having a second inlet and a second discharge section, wherein the first discharge section is in communication with the second inlet, a gear section within the compressor housing and an auxiliary compressor in communication with the gear section and the second inlet, the method comprising the step of operating the auxiliary compressor to reduce the pressure within the gear section.  
     
     
         9 . The method of  claim 8 , wherein the auxiliary compressor reduces the pressure within the gear section to approximately atmospheric pressure.