Gas compressor

Abstract

A back pressure space of a vane groove having completed communication with an intermediate-pressure supply groove communicates with a first supply section until refrigerant pressure in each of compression chambers having been partitioned by vanes of the vane grooves reach the highest pressure, and then high pressure is supplied from the first supply section. At a time point when the back pressure space having completed communication with an intermediate-pressure supply groove communicates with the first supply section of a high-pressure supply groove, the preceding back pressure space adjacent to that back pressure space on the downstream side of the rotation direction completes communication with the first supply section.

1 .- 5 . (canceled) 
     
     
         6 . A gas compressor comprising:
 a tubular cylinder block having therein a cylinder chamber in which a refrigerant is compressed;   side blocks that are attached to side parts of the cylinder block and seal an opening of the cylinder chamber on the side parts;   a rotor that rotates in the cylinder chamber and has a plurality of vane grooves opening to an outer peripheral surface facing an inner peripheral surface of the cylinder chamber at intervals in a rotation direction;   a plurality of vanes that is respectively stored in the respective vane grooves, protrudes and retracts from the outer peripheral surface, comes into sliding contact with the inner peripheral surface of the cylinder chamber, and partitions a space between the inner peripheral surface and the outer peripheral surface of the rotor into a plurality of compression chambers;   an intermediate-pressure supply section that is formed in at least one of the side blocks, communicates with a back pressure space at a groove bottom of each of the vane grooves storing the vanes for partitioning the compression chambers from a suction process to a compression process, and supplies, to the back pressure space, an intermediate pressure larger than a refrigerant pressure in each of the compression chambers from the suction process to the compression process; and   a high-pressure supply section that is formed in at least one of the side blocks, communicates with the back pressure space in each of the vane grooves storing the vanes for partitioning the compression chambers from the compression process to a discharged process after communication with the intermediate-pressure supply section has been completed, and supplies, to the back pressure space, high pressure larger than the refrigerant pressure in each of the compression chambers from the compression process to the discharged process and larger than the intermediate pressure, wherein   the high-pressure supply section is divided into a plurality of mutually independent supply sections in the rotation direction,   the second supply section that is positioned at least secondarily from the most upstream side in the rotation direction is formed into a shape in which the second supply section, while communicating with the back pressure space of one vane groove, does not simultaneously communicate with the back pressure space of the other vane groove adjacent to the vane groove on the upstream side in the rotation direction, and the high-pressure supply section is formed in a range in which it simultaneously communicates with the back pressure space of the one vane groove and the back pressure space of the other vane groove adjacent to the vane groove on the upstream side in the rotation direction.   
     
     
         7 . The gas compressor according to  claim 6 , wherein
 the upstream-side supply section and the downstream-side supply section which are mutually adjacent in the rotation direction have, in the rotation direction, an interval at which, when the back pressure space communicates with the upstream-side supply section and the downstream-side supply section in a striding manner, a total of communication cross-sectional areas with the respective supply sections becomes at least a minimum path cross-sectional area of high-pressure supply paths for supplying high pressures respectively to the respective supply sections.   
     
     
         8 . The gas compressor according to  claim 6 , wherein
 the upstream-side supply section and the downstream-side supply section are disposed at an interval in the rotation direction, and   the interval is disposed at a position communicating with the back pressure space at a rotation position of the rotor where a reduction rate of a projection stroke of the vane relative to the vane groove becomes not more than a predetermined threshold value.   
     
     
         9 . The gas compressor according to  claim 8 , wherein
 the inner peripheral surface of the cylinder chamber is formed so that:   (a) a region in which the projection stroke of the vane that is in sliding contact with the inner peripheral surface from the vane groove is increased along with rotation of the rotor in the rotation direction;   (b) a region in which the projection stroke of the vane that is in sliding contact with the inner peripheral surface from the vane groove is decreased along with rotation of the rotor in the rotation direction;   (c) a region in which the projection stroke of the vane that is in sliding contact with the inner peripheral surface from the vane groove is decreased along with rotation of the rotor in the rotation direction and in which a reduction rate thereof is smaller than that in the region in (b); and   (d) a region in which the projection stroke of the vane that is in sliding contact with the inner peripheral surface from the vane groove is decreased along with rotation of the rotor in the rotation direction and in which a reduction rate thereof is larger than that in the region in (c) and is smaller than that in the region in (b)   are sequentially successive in the rotation direction, and wherein   the interval is disposed at a position communicating with the back pressure space of the vane groove storing the vane when the vane is in sliding contact with the region in (c) on the inner peripheral surface.   
     
     
         10 . The gas compressor according to  claim 6 , wherein
 the second supply section has a space of a size that is larger in the rotation direction than a size of the first supply section positioned on the upstream side of the second supply section in the rotation direction.