新型水压变量泵的设计与特性研究

发布时间：2017-12-28 14:04

本文关键词：新型水压变量泵的设计与特性研究　出处：《西南交通大学》2017年硕士论文　论文类型：学位论文

【摘要】：在现代水压技术研究过程中,由于水特殊的物理和化学特性,使得水压元件的开发面临新材料、新结构、新工艺甚至新的设计理念等多方面的技术难题,因此发展不及油压技术成熟,造成水压元件不多且造价高。目前水压泵设计理念仍类似油压柱塞变量泵,利用柱塞在一定斜盘倾角下相对缸体作往复运动来实现流量输出。泵结构复杂,流量脉动大,无法实现油压泵"丰富多样"的控制方式、可靠性也远低于油压泵。因此,本文研制一种集成油压和水压元件的新型水压变量泵,水泵采用成熟可靠、控制性能高的油压元件来实现动力驱动和控制,采用少量结构简单、工艺要求低的水压元件(水压缸、单向阀、蓄能器等)来实现介质与能量的传输。与常规水压泵相比,不仅结构简单,而且性能优异。论文主要完成以下研究:(1)根据新型水压泵的特殊参数要求,提出了两种水压泵的设计方案,分别对两种方案的运动规律及受力进行理论分析,并且从结构可变性、结构紧凑性、加工难度和经济性等方面进行对比,选取了最优方案一。(2)基于方案模型,对水压泵的关键零部件尺寸进行了设计计算,确定单个水压缸的基本尺寸,针对水压的特殊环境,对水压缸进行了材料选型以及密封设计。基于水压缸尺寸,设计了水压泵的阀块,最后对水压泵整体结构进行了三维建模。(3)基于水压泵结构,利用ANSYS Workbench对水压泵重要零部件水压缸进行静、动力学分析。通过静力学分析得到水压缸的最大应力为114.79MPa,低于材料许用应力154.1MPa;最大变形量为0.078mm,小于许用最大挠度。因此水压缸满足静力学性能要求,但是存在优化空间。同时对水压缸进行了模态分析,结果显示水压缸动态特性良好,与激励源不会发生共振。最后分别以降低最大应力、最大变形量以及实现质量轻量化为目标,运用有限元分析方法对水压缸进行了参数化优化设计。优化结果显示模型的最大应力减小了 17.19MPa,约占优化前模型最大应力的14.98%,小于材料的许可应力。最大变形量减小了 0.013mm,约占之前最大变形量的16.46%,模型的总质量减小了 1.46kg,约占优化前质量的8.07%。因此优化设计后的模型不仅满足各项性能要求,而且较优化前有很大提高。(4)基于流体力学理论知识,对水压泵优化结构的运动学进行研究,得到了水压泵活塞的运动特性和水压泵理论输出流量曲线,从流量输出曲线得知水压泵必然存在流量脉动,针对此问题提出了在系统出口设置蓄能器来减小流量脉动的方案。运用AMESim软件建立水压泵系统的仿真模型,并对未安装蓄能器和已安装蓄能器的流量输出曲线进行对比,结果显示蓄能器能有效降低流量脉动。最后对蓄能器消减脉动的影响因素进行讨论,结果显示蓄能器的充气压力和充气体积增大,脉动就减小。
[Abstract]:In the course of the study of modern hydraulic technology, due to the physical and chemical characteristics of water hydraulic components so special, facing the development of new materials, new structures, new technology and new design ideas and other aspects of the problem, so the development of hydraulic technology not mature, causing water element and high cost. At present, the design idea of hydraulic pump is still similar to the oil pressure plunger variable pump, and the flow output is realized by using the plunger to reciprocate to the cylinder body under a certain inclined angle. The pump structure is complex and the flow pulsation is large. It can not realize the "rich and diverse" control mode of the oil pressure pump, and the reliability is far lower than the oil pressure pump. Therefore, a new hydraulic variable pump developed an integrated hydraulic and hydraulic components, the water pump adopts the mature and reliable hydraulic control components to achieve high performance drive and control, using a small number of simple structure, low technical requirements of hydraulic components (hydraulic cylinder, one-way valve, accumulator, etc.) to achieve transmission medium and energy the. Compared with the conventional hydraulic pump, it is not only simple in structure, but also with excellent performance. This paper mainly completed the following research: (1) according to the requirements of the special parameters of the new hydraulic pump, puts forward the design scheme of two kinds of hydraulic pump, the movement rules of the two schemes respectively and analyze the stress, and compared from structure variability, compact structure, processing difficulty and economic aspects, selected optimal scheme. (2) based on the program model, the design and calculation of the key parts and sizes of the hydraulic pressure pump were carried out, and the basic dimensions of the single hydraulic cylinder were determined. According to the special environment of the hydraulic pressure, the material selection and seal design of the hydraulic cylinder were carried out. Based on the size of the hydraulic cylinder, the valve block of the hydraulic pump is designed. Finally, the three-dimensional modeling of the overall structure of the hydraulic pump is carried out. (3) based on the structure of water pressure pump, the static and dynamic analysis of the hydraulic cylinder of the important parts of the hydraulic pump is carried out by using ANSYS Workbench. Through static analysis, the maximum stress of the hydraulic cylinder is 114.79MPa, which is lower than the allowable stress 154.1MPa of the material, and the maximum deformation is 0.078mm, which is smaller than the maximum allowable deflection. Therefore, the hydraulic cylinder meets the requirements of the statics performance, but there is an optimization space. At the same time, the modal analysis of the hydraulic cylinder shows that the dynamic characteristic of the hydraulic cylinder is good and does not resonate with the excitation source. Finally, with the aim of reducing the maximum stress, the maximum deformation and lightening the quality, the parametric optimization design of the hydraulic cylinder is carried out by using the finite element analysis method. The optimization results show that the maximum stress of the model is reduced by 17.19MPa, which accounts for about 14.98% of the maximum stress of the pre optimized model, which is less than the permitted stress of the material. The maximum deformation amount is reduced by 0.013mm, which accounts for about 16.46% of the previous maximum deformation. The total mass of the model is reduced by 1.46kg, accounting for about 8.07% of the pre optimized mass. Therefore, the optimized design model not only satisfies all the performance requirements, but also has a great improvement before the optimization. (4) based on the theory of fluid mechanics knowledge, research on kinematic structure optimization of the hydraulic pump, the hydraulic pump piston movement characteristics and hydraulic pump output flow from the flow curve theory, the output curve that there must be water pump flow pulsation, the accumulator to reduce the flow pulsation of the program set up in the system export. The simulation model of water hydraulic pump system is established by using AMESim software, and the flow output curve of the installed accumulator and installed accumulator is compared. The results show that accumulator can effectively reduce the flow pulsation. Finally, the influence factors of the accumulator to reduce the pulsation are discussed. The results show that the inflatable pressure and volume of the accumulator increase, and the pulsation decreases.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TH137.51

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