基于支撑力平衡的柱塞泵滑靴副油膜厚度动态求解方法

Dynamic calculation method of oil film thickness of piston pump slipper pair based on distribution support force balance

通过改进轴向柱塞泵的滑靴副与柱塞的结构设计以稳定建立滑靴油膜,这是轴向柱塞泵当前的研究热点之一。柱塞泵滑靴副油膜厚度的动态特性对分析柱塞泵滑靴副的支撑特性至关重要,为此,提出了一种基于支撑力平衡的柱塞泵滑靴副油膜厚度动态求解新方法。首先,对滑靴副的受力平衡机理进行了分析,并构建了柱塞泵运动学和动力学模型;然后,构建了柱塞泵整泵流场仿真模型,求解了包含滑靴底部支撑力、柱塞腔压力等在内的滑靴副支撑动态边界,并采用容积效率试验数据验证了整泵流场仿真的准确性;最后,建立了滑靴副油膜承载模型,分析了滑靴副油膜支撑特性,提出了基于插值计算理论的柱塞泵滑靴副油膜承载尺度动态求解方法,对1600 r/min与600 r/min两种典型工况的滑靴副油膜动态进行了计算。研究结果显示:大排量柱塞泵转速为1600 r/min时,柱塞惯性力导致高压侧油膜厚度进一步减薄,高压转低压过程中,柱塞腔内出现压力骤降,使滑靴副油膜无法形成,导致滑靴与斜盘发生刚性接触,在该区域内发生异常磨损;而在低转速工况(600 r/min)时,滑靴底面能够有效形成油膜,保证柱塞泵低速运行的可靠性。这表明基于支撑力平衡的柱塞泵滑靴副油膜厚度动态求解方法可以快速地对不同工况下的柱塞泵滑靴副油膜厚度进行求解。

Improving the structural design of the slipper pair and plunger of axial piston pump to establish a stable oil film on the sliding shoe is one of the current research hotspots in axial piston pumps.The dynamic characteristics of oil film thickness of slipper pair are important to the analysis of slipper pair supporting characteristics,hence a dynamic calculation method for oil film thickness of slipper pair of axial piston pump based on support force balance was proposed.Firstly,the mechanism of force balance of slipper pair was analyzed,and the kinematics and dynamics models of piston pump were constructed.Then,a simulation model of the flow field of the whole piston pump was constructed to solve the dynamic boundary of the slipper pair support,including the support force of the slipper bottom and the pressure of the piston chamber,and the accuracy of the flow field simulation of the whole pump was verified by using the volumetric efficiency test data.Finally,the oil film supporting load model of slipper pair was established,the oil film supporting characteristics of slipper pair were analyzed,and the dynamic solution method of oil film bearing scale of slipper pair was proposed based on interpolation calculation theory,and the dynamic calculation of oil film of slipper pair under 1600 r/min and 600 r/min typical working conditions was proposed.The experimental results show that when the speed of the large-displacement piston pump is 1600 r/min,the inertia force of the piston further reduces the thickness of the oil film on the high-pressure side.In the process of the high-pressure to low-pressure process,the pressure in the piston cavity plunges,and the oil film of the slipper pair can not be established,which leads to the rigid contact between the slipper and the swash plate,and abnormal wear occurs in this area.Under the condition of low speed(600 r/min),the oil film of slipper pair can be effectively established to ensure the reliability of low speed operation of the piston pump.The results indicate that the dynamic calculation method of oil film thickness of piston pump slipper pair based on distribution support force balance can quickly solve the oil film thickness of slipper pair under different working conditions.