【作者】 艾青林；

【导师】 杨华勇； 周华；

【作者基本信息】 浙江大学 ， 机械电子控制工程， 2005， 博士

【摘要】 当前,轴向柱塞泵的发展趋势是:高压化、高速化、大流量化。要实现这些目标的关键问题之一是要合理设计轴向柱塞泵中的各种类型的摩擦副,使之形成适当的油膜,以提高柱塞泵的工作效率和寿命。配流副是轴向柱塞泵中最关键的摩擦副之一,也是最容易磨损失效的部件。因此,为了设计性能优良的高压、高速、大流量轴向柱塞泵,研究配流副的润滑特性机理是十分重要的。 本论文以轴向柱塞泵配流副的润滑特性为研究对象,建立了轴向柱塞泵配流副润滑特性的数学模型,该数学模型的建立可以从理论上详细地描述典型配流副油膜彤成的动态过程。对配流副油膜形成进行了数值求解和仿真分析,可以得出不同工况对润滑膜厚度、泄漏流量及支承力的影响规律:其他工况一定时,油膜的平均厚度随着供油压力和油液温度的变大而变小。油膜的形成速度随着供油压力的变大而变快。油温越高,配流副泄漏流量越大;其他工况一定,配流副转速增加时,由于供油和停油周期都变短,油膜不易形成,即使形成也易遭到破坏,当转速达到3000 r/min时,盲孔个数应为6,盲孔包角应为12°;或者盲孔个数为12,盲孔包角选为15°;其他工况一定时,油膜的平均厚度随着盲孔包角的变大而变大;其他工况一定,盲孔个数增多时,油膜的振荡幅度越大。 研制了研究配流副润滑性能的轴向柱塞泵配流副润滑特性试验台,并对试验台进行了性能分析和实验调试。对微米级电液位置控制系统进行了仿真与实验研究,得出如何选取并优化影响微米级电液位置反馈控制系统性能的参数值。通过频域仿真分析得出不带PID控制的电液位置控制系统是不稳定的,加入PID控制的电液位置控制系统是稳定的。 对轴向柱塞泵配流副润滑特性进行了机理实验,可以得出:供油压力P14增大时,加载力P26随之增大。此时,如果配流副油膜厚度一定,泄漏流量则变大;供油压力P14越大,系统压力脉动越大,配流副油膜越难形成;油液温度增加时,配流副平均油膜厚度减小;配流副相对转速越大,配流副的摩擦扭矩越大,配流副更容易磨损,油膜很难建立,而且不易形成稳定的油膜;转子(摩擦盘)在压上和压下过程中,其所受的合力矩是不平衡的,高速旋转的转子将发生倾斜,油膜厚度随着变化,产生反馈作用,若将不平衡力矩控制在一定范围,且油膜刚度足够大,可使转子倾斜角度较小,不致引起摩擦副的局部接触;考察供油压力对配流副润滑特性的影响规律,对确定最佳剩余压紧力系数提供实验依据。更多还原

【Abstract】 The trend of development of axial piston pump is high pressure high rotating speed and high flow. For achieving those goals, one of the key problems is optimum design of the frictional pairs in axial piston pump. The lubricating film must be formed in frictional pairs to improve the volume efficiency and working life of axial piston pump. The port plate/cylinder block friction pair is one of the most important frictional pairs in axial piston pump, and it is easiest to be worn out. So researching for lubrication mechanism is significant to design excellent performance axial piston pump having high pressure high rotating speed and high flow characteristics etc.In the paper, researching lubrication of port plate/cylinder block friction pair is the main object. The main achievements include the contents as follow. The mathematic model of lubrication of port plate/cylinder block frictional pair was established. The formation of the lubricating film thickness is described through the theory models. The formation of the lubricating film thickness was researched and simulated. The influence of working pressure, temperature, rotating speed and structure on the lubrication can be researched through simulation. When other working condition is invariable, the lubricating film thickness decreases as the oil pressure or oil temperature increases. The film forms fast as the oil pressure increases. When the oil temperature increases, the leakage of frictional pair increases. When other working condition is invariable, the supplying oil time and stopping oil time decrease, the lubricating film is difficult to form. When the rotary speed is 3000 r/min, the blind hole in port plate should be 6 and the wrap angle of blind hole should be 12° . Or the blind hole should be 12 and the wrap angle of blind hole should be 15° . When other working condition invariable, the lubricating film thickness increases as the wrap angle of blind hole increases, and the amplitude of lubricating film increase as the number of blind hole.The lubrication test system has been designed. The performance of the lubrication test system is analyzed. The functions feature and principle of the lubrication test system are summarized. The mathematic model of the micron electrohydraulic displacement feedback control system was established and simulated. The parameters of V0/B Kce and PID are selected and optimized. The controlsystem is stabilized with PID feedback controlling, otherwise the control system is not stabilized.The lubrication mechanics experiment of typical port plate /cylinder block frictional pair was finished through the lubrication test system. The loading force increases as supplying oil pressure P14 increases. If the lubricating film thickness is invariable, the leakage of port plate will increase. When the P14 increase, the pressure ripple increases, and the lubricating film is difficult to form. The lubricating film thickness decreases as the oil temperature increases. The torque of frictional pair increases as the rotary speed increases, and the frictional pair is easy to be worn out. In this time, the lubricating film is not steady. When the cylinder block vibrates, the resultant moment is not balanced. The cylinder block will sloping. So the lubricating film is variable, and the feedback force occurs. If the resultant moment is limited in certain scope, and the lubricating film rigidity is large enough, the sloping angle of the cylinder block will be small and the concentrated wear will be avoided.The key problems and research domain have been discussed in this paper. The developing process of axial piston pump and research present state of port plate/cylinder block frictional pair were summarized. In the paper, the main research contents were determined according to the difficult problems in researching lubrication of port plate/cylinder block frictional pair in axial piston pump.The mathematic models of damp groove type continuous oil supply port plate /cylinder block and semi-perimeter double oil groove type periodical oil supply port plate /cylinder block frictional pair was established in the paper. The mathematic model of the lubricating film formation was established to illustrate the lubricating film variation and pressure and flow characteristic in the damping groove and pressure groove. The relation between lubricating film thickness and force acting on port plate was described with the mathematic models and variation regularity of the lubricating film can be acquired.In the paper, the simulation model of port plate/cylinder block frictional pair in which the lubricating film forms was established according to force balance equation and flow continuity equation with SIMULINK of MATLAB. The frictional pair includes of damp groove type continuous oil supply port plate /cylinder block frictional pair and semi-perimeter double oil groove type periodical oil supply port plate /cylinder block frictional pair. The formation of the lubricating film thicknesswas researched and simulated in all kinds of different working condition.The lubrication test system has been designed in the paper. And the lubrication test system has been developed by author which consists of pump station > lubrication test apparatus and signal measure and control system. The lubrication characteristics of port plate/cylinder block in axial piston pump such as film thickness, bearing support capability and leakage can be measured through the lubrication test system. And the influence of working pressure, temperature, rotating speed and structure on the lubrication can be testec as well. The optimal matched pair of material and structure of the port plate pair of water hydraulic axial piston pump can be achieved through the lubrication test system, which can provide a good base for developing water hydraulic axial piston pump.The mathematic model of the micron electrohydraulic displacement feedback control system was established in the paper. The dynamic properties of the micron electrohydraulic displacement feedback control system were simulated. The simulation results are conformed to the experimental results. It is suggested that the value selection of vo/ -, Ka and PID coefficient is significant for the design of themicron electrohydraulic feedback control system. The measurement error was guaranteed to be less than lum by using the high-accuracy electric eddy micro-displacement sensors. The thickness of micron dimension lubricating film was feedback controlled with PID algorithm.In the paper, the lubrication mechanics experiment of typical port plate /cylinder block frictional pair was finished through the lubrication test system. From the experiment results, the lubrication parameters of port plate/cylinder block frictional pair can be acquired. The lubrication characteristics of port plate/cylinder block in axial piston pump such as film thickness, bearing support capability and leakage can be measured. And the influence of working pressure, temperature, rotating speed and structure on the lubrication can be tested as well. The experiment results were conformed to the simulation results through comparison research.更多还原