| 摘要 |
PROBLEM TO BE SOLVED: To provide a variable displacement vane pump preventing excessive pressure rising and separation of vanes in a section transiting from an intake stroke to a discharge stroke without being affected by a change of operation condition. SOLUTION: The vane pump has a rotor 5 and a cam ring 7 eccentrically arranged, in which the vane 10 can radially slide and move in and out of a plurality of vane grooves formed in the rotor 5, vane back-pressure chambers formed in the vane grooves are connected to a back-pressure groove 13b in which discharge pressure is introduced, and the intake stroke wherein the volume of pump chambers 16 divided by adjacent vanes 10 themselves increases and the discharge stroke wherein the volume decreases are connected with a pre-compression stroke wherein the pump chamber volume decreases in a state of not opening to either an intake port or a discharge port. The vane pump is constructed that a communication path 20 is provided for connecting the pump chamber 16 in the pre-compression stroke and the back-pressure groove 13b through a check valve 19 and discharge pressure in the back-pressure groove 13b acts in a direction of closing the check valve 19. COPYRIGHT: (C)2008,JPO&INPIT
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