The CFD Simulation Analysis Of Flow Distribution Features In Axial Piston Pump A11vo190

Because of the special advantages of compact conformation, large power density, longevity of service, axial piston pump have been widely used in various types of machinery and equipment. With the continuous improvement of the axial piston pump's performance requirement, high speed, high pressure, and high flow axial piston pump with low noise is made to be a major research direction, so how to improve axial piston pump's performance and reduce its noise effectively is becoming the current research focus. Noise is one of the three performances of piston pump, and it has a crucial impact on the axial piston pump's performance. Study found that the axial piston pump noise is assignment flow which is generated in the process of assignment flow by valve plate, so how to reduce the assignment flow noise of valve plate is the key to improve axial piston pump's performance and increase its using value. Therefore, it is very necessary to reduce the noise of the piston pump by studying assignment flow property of valve plate.In the paper, a Rexroth Corporation's production of swash plate high-pressure axial piston pump A11VO190 as the research object, do numerical simulation of flow field during the process of assignment flow by using CFD methods. Taking into account the compressibility of the fluid can not be ignored under high speed and high pressure, weakly compressible state equation is added to the fluid control equations,at the same time taking into account the effect of viscosity-temperature and viscosity-pressure of oil, elicit the relational expression that viscosity decreases with pressure and temperature, and brought it into the fluid control equations, then do numerical solution. According to numerical results, do analytical study on out flow of piston pump in the process of assignment flow,we can find that numerical simulation of the outlet flow pulsation is bigger than flow pulsation which only considering geometric movement; When the piston chamber connected to the damping groove which in the valve plate slot, the flow process is influenced by throttling action. Use the method of numerical fitting to analysis the change law of the valve plate's damping groove flow coefficient when plunger cavity enter into suction and discharge chamber during the process of flow assignment. Fit the relationship between flow coefficient and turn angle according to the simulation results; contrastive analysis the opening angle and depth of the triangle damping groove in valve plate's inlet and outlet, and the structure of little hole on top of damping groove influence the piston cavity pressure change. It can be concluded that when the opening angle of triangle damping groove is 35°, the pressure change in piston is more gentle; For the damping groove depth which is controlled within about 80°, then it can be ensured that piston pump generated lower fluid noise in the process of flow assignment; For the damping groove which combine hole with groove can improve the flow pulsation of the pump, pore chamber can improve the phenomenon of pressure shock which is formed in original chamber when piston chamber deviate from high pressure chest and low pressure chest.