【作者】 张斌；

【导师】 杨华勇； 徐兵；

【作者基本信息】 浙江大学 ， 机械电子工程， 2009， 博士

【摘要】 轴向柱塞泵是液压系统中最重要的动力元件,广泛应用于各类机械装备中。轴向柱塞泵是机构和流体的统一体,机构向流体传递运动和能量,流体为摩擦副提供动力润滑油膜改善其摩擦条件,并传递出流量和压力进行做功。因此流体和机构耦合是轴向柱塞泵的基本特征,也是影响其性能的研究重点和难点。本学位论文针对轴向柱塞泵机构和流体多维模型耦合的虚拟样机技术展开研究,目的在于提高轴向柱塞泵的综合性能,为柱塞泵的结构设计和优化提供手段,具有广泛的工程应用背景和重要的学术研究价值。本学位论文创建了轴向柱塞泵液固耦合的虚拟样机环境,并研制了柱塞副油膜特性测试专用试验台,验证了虚拟样机的分析准确性,为柱塞泵的外部输出特性与内部流体特性研究提供了手段,为柱塞泵支承油膜理论研究和结构设计提供了一种新方法。针对轴向柱塞泵虚拟样机液固耦合的特点建立了机构和流体模型,机构模型包括三维刚体动力学子模型和柔性化子模型,流体模型包括流体功率传递子模型和柱塞副油膜支承子模型,通过建立接口模型链接各个子模型,进而构成了轴向柱塞泵的虚拟样机。这种建模方式考虑了柱塞泵三维运动机构的动力学因素和柱塞副油膜特性,并将其用于扭矩损失、流量损失和压力损失的计算,而解算结果又反作用于各子模型,因此该模型不仅具备传统模型的特点而且充分考虑多模型间的关联和支持。根据虚拟样机的模型特点研制了柱塞副油膜特性测试泵,其在不改变泵结构的条件下实现了柱塞副油膜压力场、温度场、油膜厚度的测试,并能够和实际泵一样驱动压力等级为0～30MPa的开式或闭式负载,可以通过无线传输的方式把高速旋转部件上的36通道的测试数据传递到数据采集系统中,是柱塞泵高速运动部件上油膜特性测试的一种新方法。基于虚拟样机模型和上述试验平台,全面分析了轴向柱塞泵虚拟样机在虚拟环境下对柱塞泵输出特性和内部流体、机构特性,这是传统方法难以实现的。和试验相比,虚拟样机仿真对开式压力、流量、转速等外特性预测的平均精确度可达96.2%,对闭式压力、流量、转矩、转速的平均精确度可达95.9%,可以满足实际性能分析需要。对于时间尺度为毫秒级的内部配流窗切换的压力、流量脉动率和试验相比的误差分别仅为0.5%、0.6%,同时通过研究可以揭示吸、排油流量脉动与局部结构之间的关系,对柱塞泵的结构优化和性能改善具有指导意义;最后,轴向柱塞泵虚拟样机技术在数字式柱塞泵和斜轴双泵交叉功率控制的设计和性能分析上进行了应用,对数字泵的控制效果和交叉功率的灵活性进行了准确的预测,证明了虚拟样机模型的通用性和广泛性,以及广泛的应用价值和良好的应用前景。论文主要结构如下:第一章,指出了论文研究的目的和意义,对国内外主要的轴向柱塞泵科研机构的相关研究情况进行了调研,综述了该领域研究现状,确定了博士学位论文研究的内容。第二章,分析并建立了柱塞泵机构模型。建立了三维多体动力学模型,对关键部件进行了柔性化处理,优化了模型中的主要影响参数,为机构模型和流体模型的联合仿真奠定了基础。第三章,针对轴向柱塞泵复杂的流体系统,分别构建了轴向柱塞泵的流体功率传动模型和柱塞副间隙油膜模型。通过对机械传动驱动流体的过程分析,建立了轴向柱塞泵的扭矩模型、流量模型和压力模型,并考虑了流体的弹性模量和惯性流量的影响。最后,创建了柱塞副油膜模型,用来求解柱塞副的压力场等油膜微观参量。第四章,研究了轴向柱塞泵虚拟样机各个子模型之间的关系,搭建了轴向柱塞泵各模型之间的接口模型,并进行了封装。第五章,提出了一种在高压高速工况下真实柱塞泵上测试柱塞副油膜的新方法,研制了柱塞副油膜测试泵和综合性能测试平台,为虚拟样机仿真提供了试验验证的手段。第六章,通过试验研究和虚拟样机仿真分析对轴向柱塞泵开式、闭式的宏观输出特性、微观输出特性、柱塞泵内部柱塞副油膜压力场特性进行了对比分析,证明了虚拟样机仿真平台对轴向柱塞泵内外部特性的仿真分析具有较高的精度。依据模型优势,对轴向柱塞泵内部节点的流体特性进行了研究,揭示了其流量、压力产生的机理。而且采用轴向柱塞泵的虚拟样机对数字泵和轴向柱塞泵双泵的交叉功率控制进行了应用分析,成功的预测了数字泵控制效果和交叉功率的灵活的功率分配策略。第七章,总结了论文的主要研究工作,给出了主要的研究结论,指出博士学位论文研究课题的创新点,并对未来的研究工作进行了展望。更多还原

【Abstract】 Axial piston pump, the most important component in hydraulic systems, is widely used in industrial machinery.In axial piston pump, the coupling of fluid and mechanism (FM) is a basic feature. On the one hand, the mechanical energy from prime mover is converted to fluid energy through moving fluid by mechanism; on the other hand, the lubrication condition of viscous friction pairs, including piston pairs, distribution pair and slipper pairs, are maintained by the FM coupling, which have a significant effect on the performance of axial piston pump. Therefore, a new approach to study FM coupling, the virtual prototype technology of axial piston pump, was mainly focused in this thesis.In this thesis, the Virtual Simulation Package of Axial piston pump (ViSPA) has been developed. In order to verify the simulation results, a test rig was set up. By comparison of simulation and experimental results, it was proved that the simulation accuracy of ViSPA can reach 96.1%. In the ViSPA, three dimension (3D) multi-body dynamics model of the pump mechanism for analysis of rigid bodies were established, and a fitness element method (FEM) flexibility model was built to study elastic-mechanics of key parts. For the FM co-simulation, the rigid and flexible models must be used together with fluid model, which take into oil film dynamics of piston pairs. The kinematic, dynamics and fluid parameters in the virtual prototype environment can be calculated simultaneously and interchanged through the interfaces in real time. Moreover, the test pump was designed and engineered to mount micro sensors in the cylinder body of pump without influence on the pump performance. So not only the external performance but also the pressure, temperature and film height inside the piston pairs can be measured in a real piston pump. Based upon the ViSPA simulation and the experiment, the pressure distribution between piston and cylinder bore inside the pump was examined. The values from experiment and simulation in the 3D distribution surface are very close in same position inside the piston chamber and in the same phase of piston rotation.In addition, the ViSPA simulation accuracy of the external and internal parameters of the pump was studied. The average simulation accuracy of output flow, pressure and rotary speed is more than 96.2% in open loop system compared with the experimental results, and it can reach 95.9% in close loop. As for pressure and flow ripple rate of axial piston pump, the difference between calculated and measured value is only 0.5% and 0.6%. Therefore, the ViSPA is an effective tool to predict the external and internal performance of axial piston pump. Also the ViSPA was applied to study cross power control of axial piston double pump and high speed on/off control in axial piston pump. Thus, the ViSPA developed can be used as a reference to study the behaviors of axial piston pump together with optimal design of pump structure.In chapter 1, the aim and significance of the study in the thesis were discussed. The current research progresses on virtual prototype technology of axial piston pump were reviewed. The main research subjects were presented.In chapter 2, the theoretical study of the pump mechanism was carried out. 3D multi-body dynamics model of the pump mechanism for analysis of rigid bodies were established, and a FEM flexibility model was built to study elastic-mechanics of key parts.In chapter 3, the fluid model of axial piston pump was studied. The power transmission of fluid model was analyzed to obtain the torque loss, the lekage flow and the pressure effect, which are important parameters inside the pump. Also the fluid model takes into oil film dynamics of piston pairs so that help to solve the pressure distribution inside piston chamber.In chapter 4, the interfaces between different models were developed and packaged in a program called ViSPA, and the GUI (Graphical User Interface) of ViSPA was programmed.In chapter 5, In order to verify the simulation results, a test rig was designed and engineered. Not only the external performance but also the pressure, temperature and film height inside the piston pairs can be measured in a test pump, which was developed by inserting micro sensors in the cylinder body of pump.In chapter 6, the ViSPA simulation and experiment results were compared and analayzed. In order to improve the performance and optimize the structure, the relationships between performance and structure inside the pump were investigated. In addition, the ViSPA simulation accuracy of the external and internal parameters of the pump was studied. The average simulation accuracy of output flow, pressure and rotary speed is more than 96.2% in open loop system compared with the experimental results, and it can reach 95.9% in close loop. As for pressure and flow ripple rate of axial piston pump, the difference between calculated and measured value is only 0.5% and 0.6%. Therefore, the ViSPA is an effective tool to predict the external and internal performance of axial piston pump.In chapter 7, conclusions in this thesis were summarized and future research proposals were suggested.更多还原