紧凑型油静压导轨系列化设计与性能分析

发布时间：2018-08-23 14:28

【摘要】：机床导轨作为机床的关键功能部件,对机床性能的提升起着重要作用。目前,由于滚珠导轨具有低摩擦、高承载、高刚度、易安装等优点,被广泛应用于机床上,但滚珠导轨的抗振性差。液体静压导轨具有比滚珠导轨更好的阻尼特性和运动精度,但传统液体静压导轨成本较高、空间占用大、安装调试困难、通用性差。因此本文综合两种导轨的优点设计了一种紧凑型油静压导轨,并对该类型静压导轨进行了系列化设计和动静特性分析。本文以液体静压导轨设计原理为理论依据,以上银滚珠导轨结构尺寸为系列化设计参数,设计了三个系列紧凑型油静压导轨(JC45、JC55和JC65),并设计了静压支承的重要部件节流器,该节流器为节流比可调缝隙节流器,节流比调节范围为1.5～3。此外,基于液体静压支承理论对紧凑型油静压导轨单滑块的性能进行了分析,结果显示不同系列紧凑型油静压导轨单滑块的承载力和刚度性能随导轨系列数的增大而增大,且变化关系呈非线性。基于结构件的弹性变形理论和流体润滑理论,建立了紧凑型静压导轨单滑块的流固耦合刚度模型。通过对模型的分析,发现结构中的变形导致了刚度性能的下降。然后,从改变滑块结构参数、补偿结构变形和调节节流比三个方面讨论了减小变形对刚度性能的影响,分析显示增加滑块宽度能有效减小滑块变形,补偿变形量能有效提高导轨刚度,当变形对节流比的影响较小时,调节节流比对导轨刚度的影响不明显。通过将油垫等效为弹簧-阻尼系统,建立了紧凑型静压导轨多滑块支承工作台的动力学模型。研究了同一系列紧凑型油静压导轨不同尺寸工作台及不同系列紧凑型静压导轨工作台的动静刚度以及阶跃响应时间。研究发现不同系列相同尺寸的工作台的动静刚度及阶跃响应时间随导轨系列数的增大而增大,对于相同系列工作台,改变工作台的特定尺寸可以改变工作台在特定方向上的动静性能及响应时间,且结构越大动静刚度越大,工作台的阶跃响应时间也越长。
[Abstract]:As the key functional part of machine tool, the guide rail plays an important role in improving the performance of machine tool. At present, ball guide rail is widely used in machine tools because of its advantages of low friction, high bearing capacity, high stiffness and easy installation, but the vibration resistance of ball guide rail is poor. The hydrostatic guide rail has better damping characteristics and motion accuracy than the ball guide rail, but the traditional hydrostatic guide rail has the advantages of high cost, large space occupation, difficult installation and debugging, and poor versatility. Therefore, a compact oil hydrostatic guide is designed based on the advantages of the two kinds of guide rails, and the series design and dynamic and static characteristics of this type of hydrostatic guide rail are analyzed. Based on the design principle of hydrostatic guide rail and the series design parameters of the silver ball guide rail, three series of compact oil hydrostatic guide rails (JC45, JC55 and JC65) are designed in this paper, and an important component throttle for hydrostatic support is designed. The throttle is a throttle ratio adjustable slot throttle, the throttle ratio adjustment range is 1.5 ~ 3. In addition, based on the theory of hydrostatic pressure support, the performance of single slide block of compact oil hydrostatic guide rail is analyzed. The results show that the bearing capacity and stiffness performance of single slide block of different series of compact oil hydrostatic guide rail increase with the increase of the number of guide rail series. The relation of variation is nonlinear. Based on the elastic deformation theory and fluid lubrication theory of structural parts, the fluid-solid coupling stiffness model of single slider of compact hydrostatic guideway is established. Through the analysis of the model, it is found that the deformation in the structure leads to the degradation of the stiffness performance. Then, the influence of reducing deformation on stiffness performance is discussed from three aspects: changing the structural parameters of the slider, compensating the structural deformation and adjusting the throttling ratio. The analysis shows that increasing the width of the slider can effectively reduce the deformation of the slider. The stiffness of guide rail can be improved effectively by compensating deformation. When the effect of deformation on throttle ratio is small, the influence of adjusting throttle ratio on the stiffness of guide rail is not obvious. By equivalent the oil cushion to the spring-damping system, the dynamic model of the compact hydrostatic guide rail with multi-slider supporting worktable is established. The static and dynamic stiffness and step response time of the same series of compact hydrostatic guide rail with different sizes and different series of compact hydrostatic guide rail worktables are studied. It is found that the dynamic and static stiffness and step response time of different series of worktables of the same size increase with the increase of the number of guide rail series. Changing the specific size of the table can change the dynamic and dynamic performance and response time of the table in a particular direction, and the larger the structure, the greater the dynamic and static stiffness, and the longer the step response time of the table is.
【学位授予单位】：山东科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG502

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