JPS5514923A - Pump device - Google Patents

Abstract

PURPOSE: To make the promotion of reducing power consumption or noise and pulsation, with a useless supply of fluid eliminated, by making a delivered fluid suppliable from a pump in one part to a hydraulic equipment, as well as a with delivered fluid made capable of returning from a pump in another part to a tank from through a flow path changeover mechanism.

CONSTITUTION: When both of pumps 2 and 3 are in an operation of low rotational speed range, a pressurized fluid from a pump 2 is fed to a power-steering gear 11 through a conduction tubing 9, 10, with a pressurized fluid from another pump 3 through flowing into a flow path changeover mechansim 4 through a conduction tubing 13 and a flow rate detecting method 5, for a solenoid 4d being deenergized because of a little amount of flow rate, the pressurized fluid from the pump 3 is wholly fed to the power-steering gear 11. With the both pumps 2, 3 increasing their rotational speeds, and a flow rate, in the flow rate detecting method 5, exceeding a prescribed level, the solenoid 4d is energized to return a total amoung of flow of the pressurized fluid from the pump 3 to a tank 8 through a flow outlet 4c and a conduction tube 7, thus eliminating a useless supply of fluid.

COPYRIGHT: (C)1980,JPO&Japio