| The hydraulic energy can be converted into mechanical energy with high efficiency by axial piston pump, then be used for the mechanical system, so the axial piston pump is widely used in the field of fluid machinery. However, with the development of high speed, high pressure and large flow of the Piston Pump, it has great significance to study the influence of internal mechanical friction,internal leakage and flow impact on volume efficiency and mechanical efficiency of the piston pump,which will be mainly determined by the working condition of the three pairs of friction pairs in the pump. Lubricating property of the spherical port plate pair is studied in this paper.,which provide some theoretical reference for further innovation and improvement of axial piston pump. The main contents of this paper are are shown as follows.The mathematical model of spherical port plate pair oil of film distribution is built,by introducing Euler angle to characterize the cylinder position, and the constraints of geometric space of actual port pair. what's more, the minimum and maximum thickness of the oil film as well as the location are determined.Research has shown that the distribution and symmetry of oil film mainly determined by cylinder block surface coordinates, and the size of the oil film thickness distribution is affected by the cylinder body posture.Pressure distribution of sealing area on port plate pairs has been obtain,utilizing the interstitial fluid dynamics model based on N-S steady laminar flow. Pressure field model of sealing area based on multilayer perceptron is built,by reference the data of non parameter of modeling method, which is proposed for the first time. The analysis showed that the large pressure and viscosity weaken the effect of the? on the pressure field, so that the linear distribution feature of the pressure field is very apparent.The holding force of oil film change dramatically,due to the uneven distribution of pressure field in the inner and outer seal area,then the force tilted cylinder block relatively greatly.Lubricating model of the spherical port plate pair has been proposed,considering unsymmetrical bias of oil film, the mapping of oil film morphology and leakage established, symmetrical and unsymmetrical slot laminar spherical valve side leakage calculation formula obtained.The result reflects that oil film thickness has a great influence on leakage theoretically,and the leakage is proportional to three cube of the offset of sphere center. At low pressure,oil film has sufficient stiffness in the range of 20~5?m film thickness,lubrication characteristics being improved by increasing the gap between the oil film, while ensuring a small volume loss.The relationship between the pair of friction torque loss and the pump working pressure,rotational speed and oil film thickness has been studied. The friction torque equation of spherical port plate pair in solid friction, boundary lubrication and liquid lubrication conditions are given completely,which provides a new way to judge the lubricating state according to the friction torque not the measurement of oil film thickness.Multi-objective particle swarm algorithm on lubrication properties of spherical port plate pair have been developed for the three main optimization goals including spherical port plate pair mechanical equilibrium, flow leakage and minimal friction torqued.The design method can clearly see the relationship of the optimization variables on the design parameters,as well as the dependence between the various indicators.This algorithm can ensure the friction lubrication and sealing performance, providing a flexible and varied scheme for selecting design parameters. |
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