Study On Low Noise Valve Plate Of Swashplate Axial Piston PUMP

In the modern hydraulic transmission, the axial piston pump is widely used in kinds of machinery because it has many advantages which include small size,great transmission powe,high efficiency,easy to control variable and long life. With the axial piston pump turn towards the development of high-pressure,high-speed and large flow, we ask higher performance and environmental requirements. And the nosie of axial piston pump is an important factor to its future development. To be as main noise source, the fluid noise is related with the structure of valve plate closely. So it has very important significance to research the valve plate structure of axial piston pump and analyze the fluid characteristics of axial piston pump in reducing noise.In this paper, a Push Corporation's production of swashplate high-pressure axial piston pump to be the research object. We have Analyzed the noise formation mechanism of piston pump, and learned the fluid noise components, Because the flow ripple which caused by geometric flow ripple and pressure impact is the main fluid noise source, so it is determined to be the main research object. Using this theory as guidance, We established the flow and pressure mathematical model of piston pump and considered the compressibility of hydraulic fluid and did the CFD analysis of the flow field in STAR-CD. In a word, this paper completed the following analysis content:the different overflow cross-sectional area of valve plate triangular damping groove and pre-boost (relief) zone closed angle have different influence on the pressure and flow characteristics of axial piston pump.This paper has the following structure:In the first chapter, it has introduced the research background, and surveyed the research situation of axial piston pump in main research institute at home and abroad. And then cleared the content and purpose of the thesis based on this;In the second chapter, it has described the principle of axial piston pump, and analyzed the noise formation Mechanism of the piston pump. And then paied the attention on the fluid noise and determined the flow ripple to be the major component of the fluid noise;In the third chapter, it established the flow and pressure mathematical model of piston pump, and introduced CFD simulation technology;In the fourth chapter, it did flow field simulation on complex internal flow characteristics of axial piston pump. We got this conclusion:the swashplate high-pressure axial piston pump can get ideal pressure flow characteristics when the valve plate has 70°～80°bottom angle on overflow cross-sectional area of valve plate triangular damping groove and 23°closed angle pre-boost (relief) zone. And this conclusion can be used as theoretical guidance in designing low noise valve plate;In the fifth chapter, we designed a vavle plate of axial piston pump with 11 pistons and proved it has excellent pressure flow characteristics through CFD simulation. This conclusion can be used as reference in current piston pump design which has 11 pistons.At last, it gave a summary on total research, got the main conclusion and looked forward the future development.