Fixed displacement piston compressor

Abstract

A compressor includes a rotary shaft, a swash plate, a cylinder block, plural pistons, a crank chamber, a housing, plural passages, a thrust bearing, and an anti-rotation mechanism. The crank chamber accommodates therein the swash plate, and refrigerant of suction pressure is introduced into the crank chamber. The housing is connected to the cylinder block and forms therein a suction chamber and a discharge chamber. The plural passages are provided for communication between the crank chamber and the suction chamber. The thrust bearing is provided between the swash plate and the cylinder block so as to receive thrust load from the swash plate. The thrust bearing has a thrust race located adjacent to the cylinder block. The anti-rotation mechanism is provided for preventing relative rotation of the thrust race to the cylinder block. The anti-rotation mechanism restricts the fluid flow through a specific passage of the plural passages.

1 . A fixed displacement piston compressor, comprising:
 a rotary shaft;   a swash plate fixed to the rotary shaft;   a cylinder block supporting the rotary shaft, the cylinder block having plural cylinder bores arranged around the rotary shaft;   plural pistons accommodated in the respective cylinder bores, the pistons being coupled to the rotary shaft through the swash plate;   a crank chamber into which refrigerant of suction pressure is introduced, the crank chamber accommodating therein the swash plate;   a housing connected to the cylinder block and forming therein a suction chamber and a discharge chamber;   plural passages for communication between the crank chamber and the suction chamber;   a thrust bearing provided between the swash plate and the cylinder block so as to receive thrust load from the swash plate, the thrust bearing having a thrust race located adjacent to the cylinder block; and   an anti-rotation mechanism for preventing relative rotation of the thrust race to the cylinder block, the anti-rotation mechanism restricting the fluid flow through a specific passage of the plural passages.   
     
     
         2 . The fixed displacement piston compressor according to  claim 1 , wherein the specific passage is one whose opening to the crank chamber is located at the lowest position as viewed in vertical direction when the compressor is installed in a vehicle. 
     
     
         3 . The fixed displacement piston compressor according to  claim 1 , further comprising an inlet port through which refrigerant of suction pressure is introduced into the crank chamber, wherein the specific passage is one whose opening to the crank chamber is located closest to the inlet port. 
     
     
         4 . The fixed displacement piston compressor according to  claim 1 , wherein each passage is formed in the cylinder block, and the opening of each passage to the crank chamber is located around the thrust race. 
     
     
         5 . The fixed displacement piston compressor according to  claim 4 , wherein the anti-rotation mechanism includes a projection formed in the periphery of the thrust race so as to extend radially outward and a retainer formed in the cylinder block so as to restrict movement of the projection, and the projection is located at a position over the opening of the specific passage. 
     
     
         6 . The fixed displacement piston compressor according to  claim 5 , wherein there is provided a gap between the opening of the specific passage and the projection. 
     
     
         7 . The fixed displacement piston compressor according to  claim 5 , wherein a pair of the retainers is formed in the cylinder block so as to project toward the swash plate, and the retainers are located on opposite sides of the projection as viewed in rotating direction of the rotary shaft so that the projection is brought into contact with the retainers. 
     
     
         8 . The fixed displacement piston compressor according to  claim 4 , wherein the anti-rotation mechanism includes a projection formed in the periphery of the thrust race so as to extend radially outward and a pin mounted to the projection, the pin being inserted in the opening of the specific passage.