To reduce a movement amount of the seal pin of a variable discharge amount vane pump to seal a pressure chamber by a seal pin, to ensure the long term use and the strength of an elastic member, and further to prevent wear of the seal pin, to reduce leakage of a pressure chamber, and stabilize operation.
A variable capacity vane pump 1 comprises a rotor 3; a vane 4; and a ring 8 oscillatorily supported by an oscillation part 7 arranged in the cavity 5 of a housing 2. In this case, an elastic member 15 and a seal pin 16 are arranged in the grooves 13 and 14 of the protrusion parts 11 and 12 if the outer peripheral part of a ring such that a pressure chamber 25 to oscillate the ring is formed in the outer periphery 10 of the ring 8. The slide contact surfaces 20 and 21 of the cavity with which the seal pin makes slide contact are formed in the shape of a circular arc 22 centering around the oscillation center 17 of an oscillation part 7.
YUNOKI YOSHINORI
SHOJI YUKIHIRO
MAEZAWA NORIHIRO
KUMAMOTO KATSUHIDE
FUJIOKA JUNICHI
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