高速小型混合陶瓷球轴承润滑分析

发布时间：2018-04-18 06:09

本文选题：陶瓷球轴承 + 弹流润滑　；参考：《西南科技大学》2017年硕士论文

【摘要】：高速深沟混合陶瓷球轴承被广泛用于我国国防军工、航空航天机械装置领域以及高速精密数控加工等行业。在高速运转的分子泵中,支承轴承由于转速高、尺寸小等特点,容易出现各种润滑不良的现象,随着润滑不良程度的加剧,导致轴承接触区的磨损加剧和温度急剧增加。随之而来要解决的问题是如何针对轴承的润滑状态进行有效的分析,才能较为准确的模拟工况,设计出精确的润滑方案以改善轴承的润滑状态,提高轴承的工作稳定性和寿命。本文针对该问题进行了相关的深入研究,以高速深沟陶瓷球轴承(QC0011286)为研究对象,运用了有关深沟球轴承的基本理论,建立了弹流润滑下高速深沟陶瓷球轴承计算模型和方法,为高速深沟陶瓷球轴承润滑改善具有一定的指导意义。(1)根据轴承具体尺寸参数,运用Siemens NX建立轴承三维模型,在赫兹接触理论的基础上,建立了高速深沟陶瓷球轴承接触静力学理论模型,分析了轴承高速深沟陶瓷球运动过程中各部件的运动关系,获得了轴承接触区压力初步判定的计算方法。(2)运用经过镜面抛光后的陶瓷球(Si_3N_4)和轴承钢(GCr15)片在多功能摩擦磨损试验机上进行摩擦测试,测得摩擦系数后与摩擦系数典型值进行对比,得出轴承压力区润滑状态进行初步判定。(3)通过运用弹流润滑理论建立了高速深沟陶瓷球轴承润滑计算模型,并利用雷诺方程对轴承接触区的压力与油膜厚度进行量纲一化并通过FORTRAN语言在VISUAL STUDIO环境中进行迭代求解。通过量纲还原得到接触区压力与膜厚矩阵,将矩阵导入到matlab中进行处理,得到接触区压力与膜厚的云图。(4)通过仿真的结果与传统公式的对比,结果相差在很小的范围内,验证了本文计算模型及方法的精确性和有效性。在高速重载和低速轻载的工况下,对不同黏度的润滑油,轴承不同的速度以及载荷情况进行仿真计算,得出轴承接触区压力、膜厚分别与润滑油黏度、轴承速度、载荷之间的关系;对沟曲率半径系数对轴承润滑状态的影响也进行了仿真计算,得出此轴承的最佳内、外沟曲率半径系数的取值;通过总结多种润滑油对轴承润滑状态的影响,得出轴承在高速下最佳润滑黏度取值范围。综上所述,本文通过静力学理论深入研究了高速深沟球轴承静态下载荷的分布并运用摩擦学、流体力学、弹性力学等理论研究了内、外沟道曲率半径系数对接触区压力和润滑膜厚的影响,以及润滑油黏度、运转速度、载荷对接触区压力和膜厚的影响,通过认识和探索轴承在高速轻载运转的情况下,陶瓷球轴承的润滑特性;并得出轴承在高速下最佳润滑黏度范围,对深沟陶瓷球轴承的设计和润滑状态的优化提供了实际的工程价值。
[Abstract]:High speed deep groove hybrid ceramic ball bearings are widely used in the fields of national defense, aerospace machinery and high speed precision NC machining.In the high speed molecular pump, the bearing is prone to various kinds of poor lubrication due to the characteristics of high speed and small size. With the worsening of poor lubrication, the wear and temperature of the contact area of the bearing increase sharply.Then the problem to be solved is how to effectively analyze the lubrication state of the bearing so as to simulate the working conditions more accurately and design an accurate lubrication scheme to improve the lubrication state of the bearing and improve the working stability and service life of the bearing.This paper has carried on the related thorough research to this question, regarding the high-speed deep groove ceramic ball bearing (QC0011286) as the research object, has applied the basic theory about the deep groove ball bearing, has established the high speed deep groove ceramic ball bearing calculation model and the method under the elastohydrodynamic lubrication.It has certain guiding significance for improving lubrication of high speed deep groove ceramic ball bearing. According to the specific dimension parameters of bearing, Siemens NX is used to establish the three dimensional model of bearing, and on the basis of Hertz contact theory,The contact statics model of high speed deep groove ceramic ball bearing is established, and the kinematic relationship of each component during the high speed deep groove ceramic ball movement is analyzed.The method of calculating the pressure of bearing contact area is obtained. (2) the friction test is carried out on a multifunctional friction and wear testing machine using the ceramic ball Si3N4) and the bearing steel GCr15) sheet, which have been polished by the mirror, and the bearing steel GCr15) sheet is used to test the friction and wear of the bearing on the multifunctional friction and wear test machine.After the friction coefficient is measured and compared with the typical value of friction coefficient, it is concluded that the lubrication state of bearing pressure zone is preliminarily determined. (3) by using elastohydrodynamic lubrication theory, the lubrication calculation model of high speed deep groove ceramic ball bearing is established.The pressure and oil film thickness in the contact region of bearing are dimensionalized by Reynolds equation and solved iteratively in VISUAL STUDIO environment by FORTRAN language.The contact area pressure and film thickness matrix are obtained by dimensionality reduction, and the matrix is introduced into matlab for processing. The cloud figure of contact area pressure and film thickness is obtained. (4) by comparing the simulation results with the traditional formula, the difference between the results is in a very small range.The accuracy and validity of the model and method are verified.Under the condition of high speed, heavy load and low speed and light load, the lubrication oil with different viscosity, the different speed and load of bearing are simulated, and the contact area pressure, film thickness and viscosity of lubricating oil and bearing speed are obtained.The relationship between loads, the influence of groove radius coefficient on bearing lubrication state is also simulated, and the optimum value of inner and outer groove radius coefficient of bearing is obtained, and the influence of various lubricating oils on bearing lubrication state is summarized by summing up the influence of various kinds of lubricating oil on bearing lubrication state.The optimum range of lubricating viscosity of bearing at high speed is obtained.To sum up, the static loading distribution of high-speed deep groove ball bearings is studied in this paper by statics theory, and the internal load distribution is studied by tribology, hydrodynamics, elastic mechanics and so on.The influence of curvature radius coefficient of outer channel on contact pressure and lubrication film thickness, as well as the influence of lubricating oil viscosity, running speed and load on contact area pressure and film thickness, is explored through understanding and exploring the condition of bearing running at high speed and light load.The lubrication characteristics of ceramic ball bearings and the optimum range of lubricating viscosity of bearings at high speed provide practical engineering value for the design and lubrication state optimization of deep groove ceramic ball bearings.
【学位授予单位】：西南科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TH133.3

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