Axial compliance

Abstract

A scroll compressor has its back pressure chamber defined by two seals. The two seals are on different planes. Locating the seals on two distinct planes allows a more direct connection for a tap through a compression chamber and the back pressure chamber. In addition, the volume of the back pressure chamber can be made significantly larger, reducing resistance at start-up of the scroll compressor.

1 . A scroll compressor comprising:
 a first scroll member having a base and a generally spiral wrap extending from its base;   a second scroll member having a base and a generally spiral wrap extending from its base, said second scroll member having a boss extending in an opposed direction from said base relative to said wrap, and a driveshaft causing orbiting motion of the scroll members relative to each other;   a housing supporting said second scroll member, said housing having a first surface adjacent to said base of said second scroll member, and a radially outer seal sealing at said first surface, said second scroll member being adjacent to a second surface of said housing on a plane spaced from said first surface and said base of said second scroll member, a radially inner seal at said second surface, and said inner and outer seals defining a back pressure chamber; and   a tap extending from a compression chamber through said base of said second scroll member and into said back pressure chamber.   
     
     
         2 . The scroll compressor as recited in  claim 1 , wherein said tap extends directly through said base along a single direction. 
     
     
         3 . The scroll compressor as recited in  claim 1 , wherein said boss extends axially away from said base and then has a surface which is adjacent to said second surface. 
     
     
         4 . The scroll compressor as recited in  claim 3 , wherein said surface is formed integrally with said boss. 
     
     
         5 . The scroll compressor as recited in  claim 3 , wherein said surface is formed as a separate part from said boss. 
     
     
         6 . The scroll compressor as recited in  claim 1 , wherein said radially inner and said radially outer seals are both received in recesses in said housing. 
     
     
         7 . The scroll compressor as recited in  claim 1 , wherein said radially inner and said radially outer seals are both received in said recesses in said second scroll member. 
     
     
         8 . The scroll compressor as recited in  claim 1 , wherein one of said radially inner seal and said radially outer seal is received in a recess in said housing, and the other of said radially inner seal and said radially outer seal is received in a recess in said second scroll member. 
     
     
         9 . A scroll compressor comprising:
 a first scroll member having a base and a generally spiral wrap extending from its base;   a second scroll member having a base and a generally spiral wrap extending from its base, said second scroll member having a boss extending in an opposed direction from said base relative to said wrap, said second scroll member receiving a driveshaft within said boss, and said driveshaft causing said second scroll member to orbit relative to said first scroll member;   a crankcase supporting said second scroll member, said crankcase having a first surface in contact with said base of said second scroll member, and receiving a radially outer seal, said second scroll member contacting a second surface of said crankcase on a plane spaced from a contact plane between said first surface and said base of said second scroll member, said second surface receiving a radially inner seal, and said inner and outer seals defining a back pressure chamber, said boss extends axially away from said base and then has a radially outwardly extending lip which contacts said second surface; and   a tap extending from said one of said compression chambers along a single direction through said base of said second scroll member and into said back pressure chamber.