【作者】 于晓东；

【导师】 陆怀民；

【作者基本信息】 东北林业大学 ， 机械设计及理论， 2007， 博士

【摘要】 静压推力轴承是重型数控加工设备的主要部件，它的性能优劣直接影响设备的加工质量和运行效率。随着各种先进制造技术的快速发展，特别是高速切削技术的出现，对于加工设备的主轴转速要求越来越高。国产重型数控加工设备目前存在的主要问题是工作台转盘的旋转速度较国外同类产品低，生产效率低，加工精度差。如何提高大型数控加工设备工作台的转速、旋转精度、加工效率和加工精度，提高国际市场竞争力是目前非常迫切的任务之一。工作台转盘旋转速度和精度是由静压推力轴承性能的理论计算、设计、加工和装配等多种因素决定的。对于静压推力轴承多采取类比设计，没有进行系统的和较精确的数值计算，没有一个完整具有自主知识产权的优化设计程序和关键技术。由于国内大型零件机械加工精度达不到要求，使得静压轴承工作时摩擦副间的间隙不均匀，在高速重载的工况下局部产生干摩擦或边界润滑，导致静压轴承局部温升，油膜破裂，进而产生局部变形，使油垫的实际结构偏离理论设计模型，限制了转速。为了探明大尺度恒流多油垫开式静压支承盘轴承的力学性能和油膜的压力状态、流动状态和温度分布情况，在黑龙江省科技攻关项目(GC05A512)“重型立式数控车床工作台静压支承轴承研究”和教育部博士点基金项目(20050214001)“重型数控机床自适应推力轴承的研究”的资助下，本文以大尺度(回转直径D＞10m)恒流多油垫开式静压支承盘为研究对象，基于计算流体动力学和润滑理论，对于扇形油腔的研究提出将该模型简化为环形平面间隙和矩形平面平板流动的假设，使得理论计算结果更符合实际流动情况，减小了理论计算结果的误差，对于圆形油腔的研究，提出等面积当量半径的概念，利用等面积圆的面积替代油垫大扇形的面积，简化了模型力学性能参数的推导。利用流体力学计算软件FLUENT对油膜的压力状态、流动状态和温度场进行三维综合数值模拟分析，揭示了恒流和恒转速情况下圆形腔和扇形腔的腔面积和腔深对摩擦副的力学性能和油膜的压力状态、流动状态和温度场的影响规律。在10米立式数控车床上实测了油膜压力、油膜厚度和温度分布，通过试验验证理论计算和数值模拟所得结论的正确性，进而通过理论与试验相结合的方式探明了此类支承的摩擦学行为和失效机理，为此类支承的模型预报、仿真、设计和计算提供了一种行之有效的方法。更多还原

【Abstract】 Hydrostatic thrust bearing is critical component in heavy type numerical control processes equipment, the capability of which directly impact the quality and operational efficiency of the processes equipment. With the development of advanced manufacturing technology, especially the appearance of quick-cutting technology, the requirement of the main shaft rotation speed is much higher. The problem, which is existed in the domestic heavy numerical control process equipment at present, is that the rotation speed of the working table is lower than that of abroad and it has low efficiency and precision. How to improve the rotation speed, running accuracy, equipment efficiency and process precision of the working table of heavy type numerical control process equipment, and how to enhance its competition in international market is one of the most urgent missions at present. The rotation speed and precision of working table are determined by many factors of thrust bearing, such as theoretical arithmetic, design, process and assembly, etc. hydrostatic thrust bearing is mostly adopts analogy design without systematical and accurate calculation. It doesn’t have integral optimization and key technology of independent intellectual property right. Due to the low precision of large scale parts, the gap between friction joints is asymmetric when thrust bearing is working. The temperature of the bearings will rise locally and the oil film will be damaged because of friction or the border lubrication under high speed and heavy-duty conditions, and then the local deformation will occurred, the oil pads will deflect the theoretical design models, and the rotation speed will be restricted.In order to discover the mechanics property, pressure state and flow state of large scale constant current multi-pad open static pressure support pan bearing, under the support of two fund items, one of which is Key R&D Project of Heilongjiang Province (GC05A512)" Research on Hydrostatic Support Bearing of Heavy Vertical Numerical Lathe Working Label, the other is Ministry of Education doctor station fund item(20050214001)" Research on Self-adapting Thrust Bearing of Heavy Numerical Machine", this paper, aiming at the large scale bearing(diameter D＞10m), based on the computational hydrodynamics and lubrication theory, presents the hypothesis for the research of the sector cavity that the model is simplified for the annular plane gap and the rectangular plane flat flow, which can make theory calculation result accord with actual flow condition and diminish the error of theory calculation result. For the research of circular oil cavity, the concept of homalographic equivalent radius is proposed, which can simplify the mechanical property parameter derivation with making use of the homalographic circle area to replace the area of oil pad big sector. By using the hydromechanics calculation software FLUENT, the three-dimensional synthetic numerical value simulation analysis on the pressure state, flow state and the temperature field of the oil film is carried out. It reveals the influence law of friction joint mechanical property, oil film pressure state, flow state and the temperature field, which is caused by the cavity area and deep of the circular cavity and sector cavity under constant current and rotational speed condition. The oil film pressure, oil film thickness and the temperature distribution are measured on 10 meter vertical numerical control lathe, and the correctness of the result made by theory calculation and numerical simulation is verified by experiments. Then, the tribology action and failure mechanism of the support is explored by combining theory with experiment. And one of the feasible methods is provided for predicting, simulating, designing and calculating the model of the support.更多还原