Variable Displacement Vane Pump

摘要

A variable displacement vane pump includes a first and a second fluid pressure chamber (31,32) where the cam ring (4) is made eccentric to the rotor (2) by a pressure difference between the first and the second fluid pressure chamber (31, 32), a control valve (21) for controlling a pressure of the first and the second fluid pressure chamber (31,32) so that an eccentric amount of the cam ring (4) is reduced to be small with an increase in a rotation speed of the rotor (2), and a flow amount limiting means (22e) for limiting a discharge flow amount of the operating fluid in the second fluid pressure chamber (32) at the time the eccentric amount of the cam ring (4) to the rotor (2) becomes small by supplying the operating fluid to the first fluid pressure chamber (31) and by discharging the operating fluid from the second fluid pressure chamber (32).