【作者】 陈文杰；

【导师】 魏建华；

【作者基本信息】 浙江大学 ， 机械电子工程， 2015， 硕士

【摘要】 本文以21Occ/rev恒压、电比例排量复合控制轴向柱塞泵为研究对象,建立了系统的数学模型,并对系统传递函数进行频域分析,揭示了恒压泵控系统因小排量工况相位裕度不足而引起稳定性差的原因,针对性地提出了采用增大旁路泄漏提高系统阻尼进而提高小排量工况压力稳定性的解决方案；此外,文章通过对液动力理论研究,结合FLUENT仿真分析,量化评估了斜孔节流方式减小液动力的效果；最后通过AMESIM仿真模型和实验测试进行了仿真和实验验证。本文的主要研究内容如下：第一章,介绍轴向柱塞泵变量控制方式分类及主要变量机构形式,通过对比国内外轴向柱塞泵变量机构及控制特性研究现状,论述了本课题研究的必要性。第二章,建立系统的数学模型,重点针对柱塞泵斜盘受力情况进行研究,推导出斜盘不平衡负载力矩公式,并提出不平衡力矩补偿方法,为后续高速、高压轴向柱塞泵的设计开发及性能优化提供理论依据。第三章,通过对恒压泵控系统传递函数推导及其频域分析,获得了轴向柱塞泵恒压控制小排量工况相位裕度不足的事实,并针对性地提出通过增大旁路泄漏方式,提高小排量工况压力稳定性的方法,为轴向柱塞泵恒压控制方式更好地适应周期性快速启停并需要小排量保压的工况,提供了有效的解决方案。此外,对电比例排量控制方式性能影响较大的稳态液动力干扰,进行液动力理论研究及FLUENT液动力仿真分析,量化评估了斜孔节流进油方式降低液动力的效果,对提高系统动态特性及先导级结构紧凑性具有积极意义。第四章,基于AMESIM平台从底层模块层面搭建虚拟样机,对柱塞泵小排量工况压力稳定性及预研方案进行仿真验证及参数优化。第五章,搭建试验测试平台,为液压泵性能测试、结构改进、性能优化提供了实验基础,并通过流量阶跃动态特性实验,验证了稳压阀对提高小排量工况压力稳定性效果。第六章,总结论文主要研究内容并指出了下一步研究方向。更多还原

【Abstract】 This paper took pressure and electric flow control axial piston pump as researching object. Through depth analysis of its working principle, mathematical model of pressure control system was established. The transfer function was analyzed on frequency domain, the result of which revealed the fact that the phase margin of constant pressure control is small, so a targeted solution with bypass leakage to enhance the pressure stability of small displacement working condition was proposed. In addition, with flow force theory and FLUENT simulation, the remarkable result of reducing flow force with oblique orifice restrictor was show on this paper. Finally, the solution was validated by AMESIM simulation and experimental test.The main contents of this paper are as follows:In chapter one, the classification and working principle of control progress of the variable displacement pump was introduced, through comparing the development of variable displacement axial piston pump and control characteristics at home and abroad institutions, the necessity of this research was pointed out.In chapter two, the mathematical model of the system was built up. The unbalanced load torque formula of the swash plate was derived by force analysis and appropriate methods was proposed to compensate it, which would be helpful to accumulate theoretical foundation for high speed and pressure pump design and optimization.In chapter three, the transfer function of the system was analyzed on frequency domain, the result of which revealed the fact that the phase margin of constant pressure control is small, so a targeted solution with bypass leakage to enhance the pressure stability at small displacement working condition was proposed, It would provide a good solution for axial piston pump with pressure control to adapt the periodic operation of small flow and pressure retain after rapid journey. As to the steady flow force interference to electric proportional displacement control, this chapter showed the quantitative effect of reducing flow force with the help of oblique orifice restrictor by FLUENT simulation and study on flow force theory, which was meaningful for proper choose of the proportional electromagnet, improvement of the forerunner level structure and the energy conservation and emissions reduction, etc.In chapter four, the pressure stability at small displacement of the axial piston pump and the preparatory scheme was validated and optimized by AMESIM simulation and experimental test.In chapter five, the experiment platform was built up to provide an experimental basis for the hydraulic pump to test performance, innovate structure and optimize performance. The remarkable result of pressure stability improvement at small displacement of the pump was showed through flow step dynamic characteristics experiment of the regulator valve.In chapter six, the main work of this paper was summarized and the subsequent research direction was pointed out.更多还原