Capacity-modulated scroll compressor

Abstract

A compressor may include a shell defining an internal volume containing compressed working fluid and first and second scrolls disposed within the internal volume. The first scroll may include a first spiral wrap. The second scroll may include a second spiral wrap, a suction inlet opening and a capacity-modulation aperture. The second spiral wrap may engage the first spiral wrap to define a pocket therebetween. The suction inlet opening may be sealed off from the internal volume. The capacity-modulation aperture may receive a valve member that is movable between a first position allowing leakage of fluid from the pocket to the suction inlet opening and a second position restricting leakage of fluid from the pocket.

What is claimed is: 
     
         1 . A compressor comprising:
 a shell defining an internal volume;   a first scroll disposed within said internal volume and including a first spiral wrap;   a second scroll disposed within said internal volume and including a second spiral wrap engaged with said first spiral wrap to form a pocket between said first and second spiral wraps, said second scroll including a suction inlet opening, a discharge passage and a capacity-modulation aperture, said suction inlet opening receiving said fluid at a first pressure and being isolated from said internal volume, said discharge passage discharging said fluid to said internal volume at a second pressure that is higher than said first pressure; and   a valve member at least partially disposed within said capacity-modulation aperture and movable between a first position in which said valve member restricts fluid to flow around a tip of said first spiral wrap to restrict fluid communication between said suction inlet opening and said pocket and a second position in which said valve member allows fluid-flow around said tip of said first spiral wrap to provide fluid communication between said suction inlet opening and said pocket.   
     
     
         2 . The compressor of  claim 1 , wherein an end of said valve member is exposed to fluid within a fluid chamber, said fluid chamber communicating with said internal volume when said valve member is in said first position and communicating with said suction inlet opening when said valve member is in said second position. 
     
     
         3 . The compressor of  claim 2 , further comprising an actuation valve movable between a first position allowing fluid communication between said fluid chamber and said internal volume and restricting fluid communication between said fluid chamber and said suction inlet opening and a second position restricting fluid communication between said fluid chamber and said internal volume and allowing fluid communication between said fluid chamber and said suction inlet opening. 
     
     
         4 . The compressor of  claim 3 , wherein moving said actuation valve into said second position allows said fluid chamber to fluidly communicate with said suction inlet opening through an aperture of an end plate of said second scroll. 
     
     
         5 . The compressor of  claim 2 , wherein said valve member moves between said first position and said second position responsive to a change in a pressure differential between said fluid chamber and said pocket. 
     
     
         6 . The compressor of  claim 1 , wherein said valve member includes a first portion and a second portion, said first portion contacting said first spiral wrap and disposed between said second portion and said first spiral wrap, said first portion being formed from a material that allows said first portion to wear faster than said second portion. 
     
     
         7 . A compressor comprising:
 a first scroll including a first end plate and a first spiral wrap extending from said first end plate;   a second scroll including a second end plate and a second spiral wrap extending from said first end plate and engaged with said first spiral wrap, said second end plate including a suction inlet opening and first and second capacity-modulation apertures;   first and second valve members at least partially disposed within said first and second capacity-modulation apertures, respectively, and movable to selectively provide first and second leakage paths around a tip of said first spiral wrap;   a manifold including first and second chambers and a fluid passageway fluidly connecting said first and second chambers, said first and second chambers being aligned with said first and second capacity-modulation apertures, respectively, and portions of said first and second valve members are exposed to said first and second chambers; and   an actuation valve in fluid communication with said fluid passageway and movable between a first position providing fluid communication between said fluid passageway and said suction inlet opening and a second position providing fluid communication between said fluid passageway and a fluid source having a fluid pressure that is greater than a fluid pressure of said suction inlet opening.   
     
     
         8 . The compressor of  claim 7 , wherein said first and second capacity-modulation apertures are positioned so that said first and second leakage paths fluidly connect said suction inlet opening with one or more pockets defined by said first and second spiral wraps. 
     
     
         9 . The compressor of  claim 7 , further comprising first and second pockets defined by said first and second spiral wraps, said first and second pockets being sealed off from said suction inlet opening when said first scroll is in a first orbital position, wherein said first and second capacity-modulation apertures are positioned so that when said first scroll is in said first orbital position and said actuation valve is in said first position, said first leakage path allows leakage from said first pocket to said second pocket and said second leakage path allows leakage from said second pocket to said suction inlet opening. 
     
     
         10 . The compressor of  claim 9 , wherein said second scroll includes a third capacity-modulation aperture disposed between said first and second capacity-modulation apertures. 
     
     
         11 . The compressor of  claim 10 , further comprising a third valve member at least partially disposed within said third capacity-modulation aperture and movable therein to selectively provide a third leakage path around a tip of said first spiral wrap, and wherein said manifold includes a third chamber in communication with said fluid passageway and aligned with said third capacity-modulation aperture. 
     
     
         12 . The compressor of  claim 7 , further comprising a shell defining an internal volume in which said first and second scrolls are disposed, and wherein said fluid source is said internal volume. 
     
     
         13 . The compressor of  claim 7 , wherein said fluid passageway is in communication with said suction inlet opening through an aperture formed in said second end plate when said actuation valve is in said first position. 
     
     
         14 . A high-side compressor including a shell defining an internal volume containing compressed working fluid and first and second scrolls, said first scroll including a first spiral wrap, said second scroll including a second spiral wrap, a suction inlet opening and a capacity-modulation aperture, said second spiral wrap meshingly engaging said first spiral wrap to define a pocket therebetween, said suction inlet opening being sealed off from said internal volume, said capacity-modulation aperture receiving a valve member that is movable therein between a first position allowing leakage of fluid from said pocket to said suction inlet opening and a second position restricting leakage of fluid from said pocket. 
     
     
         15 . The high-side compressor of  claim 14 , wherein said valve member allows leakage of fluid from said pocket around a tip of said first spiral wrap to said suction inlet opening. 
     
     
         16 . The high-side compressor of  claim 14 , further comprising another valve member movable within another capacity-modulation aperture formed in said second scroll between a first position allowing leakage of fluid from said pocket to said suction inlet opening and a second position restricting leakage of fluid from said pocket. 
     
     
         17 . The high-side compressor of  claim 16 , wherein said valve members are independently controllable and independently movable between said first and second positions. 
     
     
         18 . The high-side compressor of  claim 16 , further comprising a manifold and an actuation valve operable in a first position to supply fluid to said valve members at a first pressure to move the valve members to said first position and operable in a second position to supply fluid to said valve members at a second pressure that is higher than said first pressure to move said valve members to said second position. 
     
     
         19 . The high-side compressor of  claim 18 , wherein an end plate of said second scroll includes a fluid passageway in communication with said suction inlet opening, and wherein said actuation valve is in communication with a fluid passageway in said first position. 
     
     
         20 . The high-side compressor of  claim 19 , wherein said actuation valve is in communication with said internal volume in said second position. 
     
     
         21 . The high-side compressor of  claim 20 , wherein said valve members allow leakage of fluid around a tip of said first spiral wrap to said suction inlet opening.