Dual volume-ratio scroll machine

Abstract

The present invention provides the art with a scroll machine which has a plurality of built-in volume ratios along with their respective design pressure ratios. The incorporation of more than one built-in volume ratio allows a single compressor to be optimized for more than one operating condition. The operating envelope for the compressor will determine which of the various built-in volume ratios is going to be selected. Each volume ratio includes a discharge passage extending between one of the pockets of the scroll machine and the discharge chamber. All but the highest volume ration utilize a valve controlling the flow through the discharge passage.

1 . A scroll machine comprising: 
 a shell having an end cap, said end cap defining a barrier between a chamber defined by said shell and an environment outside said scroll machine;    a first scroll member disposed within said chamber having a first spiral wrap projecting outwardly from a first end plate;    a second scroll member disposed within said chamber having a second spiral wrap projecting outwardly from second end plate, said second scroll wrap being interleaved with said first spiral wrap;    a drive member for causing said spiral wraps to orbit with respect to one another whereby said spiral wraps create pockets of progressively changing volume between a suction pressure zone at a suction pressure and a discharge pressure zone at a discharge pressure;    a first annular seal engaging said end cap and said first scroll member, said first annular seal being disposed around a hole extending through said end cap.    
     
     
         2 . The scroll machine according to  claim 1  wherein said first annular seal comprises a floating seal disposed within a cavity defined by said first scroll member.  
     
     
         3 . The scroll machine according to  claim 2  further comprising a second annular seal disposed between said floating seal and said first scroll member.  
     
     
         4 . The scroll machine according to  claim 3  further comprising a third annular seal disposed between said floating seal and said first scroll member.  
     
     
         5 . The scroll machine according to  claim 2  further comprising a passage for placing compressed fluid at a pressure intermediate said suction pressure and said discharge pressure in fluid communication with said cavity to pressure bias said first scroll member toward said second scroll member.  
     
     
         6 . The scroll machine according to  claim 1  further comprising a second annular seal engaging said end cap and said first scroll member, said second annular seal surrounding said first annular seal to define a pocket.  
     
     
         7 . The scroll machine according to  claim 6  further comprising a passage for placing compressed fluid at a pressure intermediate said suction pressure and said discharge pressure in fluid communication with said pocket to pressure bias said first scroll member toward said second scroll member.  
     
     
         8 . The scroll machine according to  claim 1  further comprising a radially compliant drive mechanism disposed between said drive member and said second scroll member.  
     
     
         9 . The scroll machine according to  claim 1  wherein said first annular seal is moveable between a first position where said first annular seal engages said end cap and said first end plate and a second position where a leak is defined between said first annular seal and one of said end cap and said first scroll member.  
     
     
         10 . The scroll machine according to  claim 1  further comprising a vapor injection system in communication with one of said pockets of progressively changing volume.  
     
     
         11 . The scroll machine according to  claim 1  further comprising a capacity modulation system operable to vary the capacity of said scroll machine.  
     
     
         12 . The scroll machine according to  claim 1  wherein said first annular seal engages an internal surface of said end cap.  
     
     
         13 . A scroll machine comprising: 
 a shell defining a chamber;    a first scroll member disposed within said chamber having a first spiral wrap projecting outwardly from a first end plate;    a second scroll member disposed within said chamber having a second scroll wrap projecting outwardly from a second end plate, said second scroll wrap being interleaved with said first spiral wrap;    a drive member for causing said spiral wraps to orbit with respect to one another whereby said spiral wraps create pockets of progressively changing volume between a suction pressure zone of said chamber at a suction pressure and a discharge pressure zone of said chamber at a discharge pressure;    a discharge fitting attached to said shell in direct communication with an area outside of said scroll machine and in communication with said discharge pressure zone through a hole in said shell; and    a first annular seal engaging said shell and said first scroll member, said first annular seal being disposed around said hole in said shell to isolate said discharge pressure zone from the rest of the chamber defined by the shell.    
     
     
         14 . The scroll machine according to  claim 13  wherein said first annular seal comprises a floating seal disposed within a cavity defined by said first scroll member.  
     
     
         15 . The scroll machine according to  claim 14  further comprising a second annular seal disposed between said floating seal and said first scroll member.  
     
     
         16 . The scroll machine according to  claim 15  further comprising a third annular seal disposed between said floating seal and said first scroll member.  
     
     
         17 . The scroll machine according to  claim 14  further comprising a passage for placing compressed fluid at a pressure intermediate said suction pressure and said discharge pressure in fluid communication with said cavity to pressure bias said first scroll member toward said second scroll member.  
     
     
         18 . The scroll machine according to  claim 13  further comprising a second annular seal engaging said end cap and said first scroll member, said second annular seal surrounding said first annular seal to define a pocket.  
     
     
         19 . The scroll machine according to  claim 18  further comprising a passage for placing compressed fluid at a pressure intermediate said suction pressure and said discharge pressure in fluid communication with said pocket to pressure bias said first scroll member toward said second scroll member.  
     
     
         20 . The scroll machine according to  claim 13  further comprising a radially compliant drive mechanism disposed between said drive member and said second scroll member.  
     
     
         21 . The scroll machine according to  claim 13  wherein said first annular seal is moveable between a first position where said first annular seal engages said end cap and said first end plate and a second position where a leak is defined between said first annular seal and one of said end cap and said first scroll member.  
     
     
         22 . The scroll machine according to  claim 13  further comprising a vapor injection system in communication with one of said pockets of progressively changing volume.  
     
     
         23 . The scroll machine according to  claim 13  further comprising a capacity modulation system operable to vary the capacity of said scroll machine.  
     
     
         24 . The scroll machine according to  claim 13  wherein said first annular seal engages an internal surface of said end cap.