Valve structure for a compressor

Abstract

A variable displacement compressor includes a rotary valve coupled to a drive shaft. The rotary valve is centrally received in a suction chamber of the variable displacement compressor and extends through an aperture formed in a cylinder block thereof. The rotary valve has a suction opening cooperating with the cylinders to successively provide a direct fluid communication between the suction chamber and each of the cylinders.

What is claimed is: 
     
         1 . A rotary valve for controlling a supply of refrigerant gas to cylinders in a variable displacement compressor, the rotary valve comprising:
 a disc portion;   a substantially cylindrical stem portion extending axially from the disc portion, the disc portion and the stem portion configured to be coupled to a drive shaft of the compressor; and   a suction opening formed in the disc portion and configured to permit direct fluid communication between a suction chamber and at least one cylinder of the compressor.   
     
     
         2 . The rotary valve of  claim 1 , wherein the suction opening has a shape adapted to axially align the suction opening with a shape of a portion of the at least one cylinder. 
     
     
         3 . The rotary valve of  claim 1 , wherein the suction opening extends arcuately in the disc portion at an angle between about 90 degrees and 180 degrees. 
     
     
         4 . The rotary valve of  claim 1 , wherein the disc portion includes a balancing feature formed thereon. 
     
     
         5 . The rotary valve of  claim 1 , further comprising an aperture centrally disposed in the stem portion and extending through the disc portion and a slot continuous with the aperture, the aperture and the slot are configured for receiving the drive shaft. 
     
     
         6 . The rotary valve of  claim 1 , further comprising a distribution feature including a channel formed on a first surface thereof for receiving a lubricant and a plurality of grooves formed on an outer wall thereof, the plurality of grooves in fluid communication with the channel. 
     
     
         7 . The rotary valve of  claim 1 , wherein at least a portion of at least one of the stem portion and the disc portion is formed from one of a ferrous material and aluminum and coated with at least one of a low friction and seizure resistant material. 
     
     
         8 . A rotary valve assembly for controlling a supply of refrigerant gas to cylinders in a variable displacement compressor, the rotary valve assembly comprising:
 a rotary valve including a disc portion, a substantially cylindrical stem portion extending axially from the disc portion, the disc portion and the stem portion configured to be coupled to a drive shaft of the compressor, and a suction opening formed in the disc portion;   a valve plate assembly including a central aperture formed therein, the aperture receiving the rotary valve; and   a plurality of suction apertures formed in the valve plate assembly, wherein the suction opening aligns with at least one of the suction apertures to permit direct fluid communication between a suction chamber and at least one cylinder of the compressor.   
     
     
         9 . The rotary valve assembly of  claim 8 , wherein the suction opening extends arcuately in the disc portion between about 90 degrees and 180 degrees. 
     
     
         10 . The rotary valve assembly of  claim 8 , wherein the rotary valve includes an aperture centrally disposed therein and a slot continuous with the aperture for receiving the drive shaft. 
     
     
         11 . The rotary valve assembly of  claim 8 , wherein the valve plate assembly includes an outer portion and an inner portion, the outer portion having a thickness greater than a thickness of the inner portion. 
     
     
         12 . The rotary valve assembly of  claim 8 , wherein the valve plate assembly includes a valve plate and a wear plate, the valve plate having a centrally disposed aperture for receiving the disc portion of the rotary valve and the wear plate having a centrally disposed aperture for receiving the stem portion of the rotary valve. 
     
     
         13 . The rotary valve assembly of  claim 12 , wherein the valve plate is formed from a material having a coefficient of thermal expansion substantially the same as a coefficient of thermal expansion of at least one of the rotary valve, a cylinder block of the compressor, and a rear head of the compressor defining the suction chamber. 
     
     
         14 . A variable displacement compressor, comprising:
 a cylinder block having a plurality of cylinders annularly formed therein and a centrally formed aperture, a plurality of pistons received within the cylinders;   a rear head disposed adjacent one end of the cylinder block and defining a suction chamber and discharge chamber;   a crank case forming a crank chamber adjacent an other end of the cylinder block;   a drive shaft rotatably received in the aperture of the cylinder block and extending through the crank chamber;   a swash plate assembly rotatably coupled to the drive shaft, the swash plate assembly operably coupled to the pistons to cause a reciprocating motion thereof;   a rotary valve coupled to the drive shaft, the rotary valve centrally received in the suction chamber and extending through the aperture formed in the cylinder block, wherein the rotary valve has a suction opening cooperating with the cylinders to successively provide a direct fluid communication between the suction chamber and each of the cylinders.   
     
     
         15 . The variable displacement compressor of  claim 14 , wherein a direction of flow of a refrigerant gas from the suction chamber to the cylinders is parallel to a longitudinal axis of the cylinders. 
     
     
         16 . The variable displacement compressor of  claim 14 , wherein the rotary valve includes a disc portion, a substantially cylindrical stem portion integrally formed with and extending axially from the disc portion, the disc portion and the stem portion configured to be coupled to a drive shaft of the compressor, the suction opening formed in the disc portion. 
     
     
         17 . The variable displacement compressor of  claim 14 , wherein the suction opening successively aligns with each of the cylinders during a suction stroke of the each of the pistons therein. 
     
     
         18 . The variable displacement compressor of  claim 14 , further comprising a valve plate assembly disposed intermediate the cylinder block and the rotary valve, the valve plate assembly having a plurality of suction apertures formed therein, each of the suction apertures aligning with one of the cylinders. 
     
     
         19 . The variable displacement compressor of  claim 18 , wherein the valve plate assembly includes a valve plate and a wear plate, the valve plate having a centrally disposed aperture for receiving the disc portion of the rotary valve and the wear plate having a centrally disposed aperture for receiving the stem portion of the rotary valve, 
     
     
         20 . The variable displacement compressor of  claim 14 , wherein the valve plate assembly includes an outer portion and an inner portion, the outer portion having a thickness greater than a thickness of the inner portion, wherein the valve plate is formed from a material having a coefficient of thermal expansion substantially the same as a coefficient of thermal expansion of at least one of the rotary valve, the cylinder block, and the rear head defining the suction chamber.