Internal relief type gear pump

Abstract

The invention relates to an internal relief type gear pump which comprises a pump body. An overflow valve is arranged in the pump body and comprises a valve sleeve and a valve core assembly which is slidably assembled in the valve sleeve; the valve core assembly comprises an inlet valve core, an outlet valve core and connecting pieces which are connected with the inlet valve core and the outlet valve core correspondingly, so that the inlet valve core and the outlet valve core slide synchronously; and the cross section area of the inlet valve core is larger than the cross section area of the outlet valve core, and the valve core assembly is connected with a pressure balancing device used for balancing the pressure difference between the inlet valve core and the outlet valve core. The overflow valve comprises the valve sleeve and further comprises the inlet valve core and the outlet valve core which are slidably assembled in the valve sleeve, the cross section area of the inlet valve core is larger than the cross section area of the outlet valve core, most of hydraulic force between the two valve cores are mutually counteracted through an area valve, and compared with a general safeoverflow valve, design of a proper spring to realize adjusting with large range and high precision is more convenient.

Description

technical field [0001] The invention relates to an internal leakage gear pump. Background technique [0002] The internal leakage gear pump is composed of a differential pressure relief valve and a gear pump. When the gear pump is working, the relief valve ensures the stability of the outlet pressure of the pump and prevents the system pressure from being too high. For example, the Chinese utility model patent whose authorized announcement number is CN205823627U and whose authorized announcement date is December 21, 2016 discloses a motor gear pump with overflow valve. Oil port, the left end of the valve hole is connected with the through hole of the high pressure chamber, the right end of the valve hole is connected with the oil drain port, the valve stem is installed at the left end of the valve hole, and a steel pipe is installed between the groove of the left end surface of the valve stem and the through hole of the high pressure chamber. The ball is fitted with a sprin...

AI Technical Summary

Problems solved by technology

[0003] The purpose of the present invention is to provide an internal leakage gear pump to solve the problem that the pressure difference in the gear pump in the prior art is large when the overflow valve is opened and closed, and precise control cannot be realized

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