VARIABLE CAPACITY TYPE VANE COMPRESSOR

PURPOSE:To increase the maximum capacity reducing rate of a variable capacity type vane compressor, by increasing the suction volume of compressed gas by positioning a second suction port forwardly of a succeeding vane of a pair of vanes defining a work chamber having a maximum volume in the direction of rotation of a rotor. CONSTITUTION:A second suction port 29 is formed at a position located forwardly of a succeeding vane 23b of a pair of vanes defining a work chamber 25 having a maximum volume in the direction of rotation of a rotor 22, so that pressure in the work chamber 25 is lowered to the level of suction pressure when a preceding vane 23 has reached the starting edge S of the second suction port 29 and gas is drawn into the work chamber 25 from the port 29 immediately when the vane 23 has passed the starting edge S of the port 29 (at the time, the succeeding vane 23b passes through a first suction port 26). With such an arrangement, it is enabled to reduce the capacity of a variable capacity compressor by a rate corresponding to the volume of the work chamber 25 ranging from the top position P to the starting edge S of the second suction port 29, and this volume provides the maximum reduction volume of the variable capacity compressor.