| 摘要 |
PURPOSE:To obtain an unload function with a simple construction, by pressing a vane against a cam ring by oil pressure inside a groove in a discharging range into which discharging pressure of a pump is led through an orifice, while allowing the groove in this discharging range to be connected to a low pressure side by a valve. CONSTITUTION:In an oil pump in which oil is charged from an intake passage 4a into the pump chamber between vanes 16, 16 by rotation of a rotor 12 to press the oil so as to discharge it from a discharging port 18a, it is formed so that discharged pressure P2 is led into the groove 18d in a suction range through a through hole 18e, and moreover the discharged pressure P2 is led into the groove 18c in a discharging range through an orifice 18f. In a normal condition, since pressure P1 in the groove 18c is high and the relation between the pressure P1 and P2 is P1) P2, the vanes 16 are brought in certain pressure contact with a cam ring 14. And also it is so constituted that a valve 26 is retreated by electrifying a solenoid 25, and pressure P1 is reduced by communicating a groove 4d formed in the discharging range with the environmental space of an input shaft 10, and the vane 16 is placed apart from the cam ring 14 so as to stop a pump function. |
