| 摘要 |
PURPOSE:To improve the number of occurring times of cavitation of an oil pump having two pump cartridges. CONSTITUTION:A pump body 2 is provided at its interior with two pump cartridges 8 and 10 of the one being a main pump cartridge and the other being a subpump cartridge and a control valve 52 to selectively feed pressure oil delivered from the two pump cartridges 8 and 10 to power steering devices P and S. When the control valve 52 is operated, reflux of a total amount of oil delivered from the subpump cartridge 10 to a low pressure chamber 46 on the suction side is carried out and delivery oil from the main pump cartridge 8 is partially fed to the power steering devices P and S and reflux of a surplus flow rate to the low pressure chamber 46 on the suction side is carried out. A suction passage 47 from a tank is opened in a reflux hole 74 extending from the main pump cartridge 8. A throttle part through which a part of a reflux amount from the subpump cartridge 10 is fed to the main pump cartridge 8 side is formed. |
