| 摘要 |
PROBLEM TO BE SOLVED: To provide stable flow rate characteristics even when a load pressure is fluctuated. SOLUTION: A variable orifice 25 is provided between the pump chamber 12 on the discharge side of a vane pump and a discharge port 18, and a pressure in a spot situated upper stream from the variable orifice 25 is introduced to a first fluid pressure chamber 31 on the outer periphery of a cam ring 5 through a control valve 40. Meanwhile, a pressure in a spot situated downstream from the variable orifice 25 is introduced to a second fluid pressure chamber 31 through an annular gap 61, and a pressure in a spot situated upper stream from the variable orifice 25 is introduced through an orifice 62. An annular gap 61 is provided between the through-hole 3a of an adapter ring 3 and the outer periphery of a feedback pin 60 piercing through the through-hole 3a and making contact with the side face on the second fluid pressure chamber 32 side of the cam ring 5. The feed back pin 60 is brought into contact with the tip of a control piston 21, incorporating a spring 22, on the base end side, and the opening area of the variable orifice 25 is narrowed through backward movement of the control piston 21.
|
