Study On Cavitation Mechanism Of Large Displacement Axial Piston Pump Andanti-cavitation Structure Of Distribution Pair

Axial piston pump with high working pressure,large displacement and high volume efficiency is widely used in various fields of the machinery industry.With the innovation of large machinery application technology and the demand for energy saving,the demand for high pressure and large displacement of piston pump is increasing.However,as the displacement of the plunger pump increases,the cavitation problem of its internal oil flow field becomes more serious,which directly affects the improvement of the performance of the plunger pump and the stability of its operation.Therefore,it is of great significance to explore the mechanism of the cavitation phenomenon of the axial plunger pump with large displacement and to study the inhibition of cavitation development.Based on the natural science foundation of Shanxi Province project(201701D121070),Shanxi Province science and technology major projects(GJHZ201602)and institutions of higher learning in Shanxi Province under the support of science and technology innovation project(201802089),with large displacement axial piston pump as the research object,explore the internal mechanism,cavitation plunger pump cavitation resistance structure is put forward,based on professional Pumplinx fluid simulation platform,the plunger pump internal unsteady flow field numerical simulation analysis,parsing resistance to cavitation effect on the properties of plunger pump structure,finally bring forward the scheme of optimization of structure parameters and its simulation.Firstly,by analyzing the domestic and foreign research status of cavitation and anti-cavitation structure of the axial piston pump,the mechanism and influencing factors of cavitation in the piston pump are analyzed macroscopically according to the complex flow channel structure inside the piston pump,the conversion of high and low pressure and the characteristics of high-speed rotation of the cylinder block to cut the flow pair oil.The mathematical model of cavitation bubble pressure and dynamics was established,and the process of bubble precipitation,development and collapse was analyzed microscopically.The influence of cavitation bubbles on the properties of oil,such as temperature,density and compressibility,is analyzed.Then,with the aid of Pumplinx professional fluid simulation platform,to extract fluid domain mesh and sliding grid refinement divided into action,plunger pump is analyzed in different parts of the fluid flow pattern,application of full cavitation model and define the oil medium and boundary conditions,the domain of fluid pressure and the distribution of gas volume fraction is analyzed,and the issues of plunger pump test work compared to get: plunger pump oil suction mouth,deputy high and low pressure flow transition zone and the plunger cylinder body cavity cavitation gas volume fraction is higher.In view of the plunger pump oil suction mouth widely distributed and plunger pump cavitation phenomenon within the oil flow characteristics,puts forward flow plate tilt oil absorption waist shape hole cavitation resistance structure,and puts forward the shaft section for the parallelogram tilt(one-way)and isosceles trapezoid(tilt)garment of waist fractal pore structure,resolve a wide variety of flow table tilt waist shape hole on the improvement of the imbibition of plunger pump and oil the influence of the shear performance of abated.Is obtained by simulation analysis: flow plate tilt waist shape hole can effectively reduce the cavitation gas distribution and local oil gas content of about 10% from its peak,improved the plunger pump oil absorption speed of the oil in the process of mutation,reduces the oil jet jet Angle,implements the flow disc waist shape hole oil gas content overall decrease about 2%.Finally,the optimization of structure of plunger pump cavitation resistance is a function of the complex and nonlinear,cavitation resistance based on Kriging interpolation model agency Gauss function relationship between the structure parameters,the sampling comparison analytic data error,predict the target data value,through the maximum particle hybrid optimization algorithm of optimization,until the objective function converges to the optimal value of cavitation gas volume fraction,the optimized: flow plate tilt oil absorption waist shape hole cavitation resistant structure of the optimal structure parameters for:axial deflection Angle is 75.7 ° and downstream tilt Angle is 8.2 °.Simulation results show that the optimized anti-cavitation structure has an impact on the cavitation phenomenon in the plunger cavity and the lumbar hole of the distribution disc.The gas volume fraction in the plunger cavity is reduced by about 2% to the maximum and the gas volume fraction in the lumbar hole of the distribution disc is reduced by about 2.5%.