Patent ID: 6036450
Filing Date: 2000-03-14
Classification: F04C

Abstract:
A variable capacity vane compressor comprising:a cylinder block;a rotor rotatably received in said cylinder block;a plurality of vanes each of which is radially slidably fitted in a corresponding vane slit formed in said rotor;two side members secured to opposite end faces of said cylinder block, respectively;a rotary plate mounted in one of said side members, for adjusting compression starting timing to thereby increase or decrease capacity of said compressor;a main piston slidably mounted in said one of said side members, for causing rotation of said rotary plate between a maximum capacity position and a minimum capacity position;a pilot piston slidably arranged at one end of said main piston, for inhibiting movement of said main piston in a capacity-decreasing direction;a first low-pressure chamber formed within another end portion of said main piston, into which suction pressure is introduced via a first low-pressure communication passage;a high-pressure chamber defined by a reduced-diameter portion formed on said one end of said main piston and one end face of said pilot piston, into which is introduced control pressure for driving said main piston and said pilot piston:a second low-pressure chamber formed at another end of said pilot piston, into which suction pressure is introduced via a second low-pressure communication passage;a main urging member urging said main piston in said capacity-decreasing direction; andan auxiliary urging member urging said main piston in a capacity-increasing direction by way of said pilot piston,wherein said second low-pressure communication passage has a cross-sectional area which is smaller than a cross-sectional area of said first low-pressure communication passage.