Research On Variable Displacement Mechanism Of Constant Power Axial Piston Pump

Axial piston pump constant power control can be maintained constant hydraulic input power source, in order to take full advantage of the installed power of the prime mover and avoid wasting energy; while avoiding excessive load on the prime mover, in particular to avoid the internal combustion engine due to the too large load, cause flameout, so-called "choke car" phenomenon,so research carried out about constant power axis piston pump has important practical value. In addition, the research of the A37 axial piston pump in the research of the constant power in thinking is different from other similar pumps, also has important theoretical research value. In this paper, the research objective is Yuken A37 constant power axial piston pump.The way of achieving constant power, the torque of swash plate and static and dynamic characteristics of variable control system were studied, using the means of theoretical analysis and numerical combination.Firstly, carrying on the analysis of the typical constant power control mode, the analysis that Youyan A37 constant power of axial piston pump is based on the principle of "compensation" to realize constant power control, and other constant power implementation is different in nature. Compared with other variable control mechanisms, the A37 constant power control of oil research is characterized by its simple structure and low cost.Based on the research A37 constant power of axial piston variable displacement pump principle, improving the structure of flow induction valve and imagine boldly three styles: single spring and T shaped notches, double valve parallel structure,. AMESim model is established, and analysis the effect of the structure size of the T shaped groove on constant power curve; try to find flow area curve by constant power curve and find a relatively simple valve structure, which is verified in AMESim model; the idea of double valve parallel structure is also carried out to validate, finally, the size of the power fluid are analyzed for the different forms of valve port.Secondly, from the point of view of dynamics, the derivation of the swash plate movement when the moment equations, analysis of the swash plate eccentricity’s effect on torque; based on the analysis of torque in the swash plate movement, comparing spring supporting with piston supporting structure of two forms of the swash plate supporting stiffness; and the swash plate fixed at a certain angle, the swash plate in three directions of torque and a resultant moment were analyzed, the swash plate between the spindle and the eccentric distance impact are analyzed.Then deducing the constant power of axial piston pump variable control system transfer function, analysising the related factors that affect the control system stability, rapidity and accuracy based on the transfer function, using AMESim software were further tested and found the main factors influencing the dynamic characteristic has two: differential pressure valve flow gain and variable piston area, finally the static characteristics are analyzed and get the main factors causing the static error.