高速角接触球轴承油气润滑二相流温升数值分析

发布时间：2018-10-15 18:33

【摘要】：高速电主轴是高速加工机床的核心功能部件,角接触球轴承是高速电主轴主要的支承方式。角接触球轴承高速运行中的摩擦发热是导致其过早失效的主要因素,因此良好润滑和冷却对保证轴承的正常运行至关重要。油气润滑作为近年来发展起来的一种新型气液两相流冷却润滑技术,以其优良的性能和清洁环保特性成为了高速轴承润滑冷却的首选。鉴于此,本文对角接触球轴承油气润滑二相流温升进行了深入分析。本文基于轴承生热理论,分析了油气润滑的条件下角接触球轴承的生热的机理,计算了不同条件下的轴承生热率和对流换热系数。建立了7006C角接触球轴承轴承腔的几何模型,并利用Fluent从转速、供油量、供气压力、润滑油粘度、入口位置、入口数目6个方面对其进行了温度场数值分析,分析结果表明:(1)轴承腔内的高温区主要分布在滚动体与滚道接触的区域,这是由接触区的摩擦生热和润滑油的搅动生热导致的;轴承腔油气入口区的温度相对最低,距离入口区最远的出口区温度最高。(2)随着转速的提高,轴承腔内温度显著提高,且升高幅度越来越大;随着供油量的增加轴承腔内温度先降低后升高,存在一个最佳供油量。(3)压缩空气在油气润滑中不仅是传递油液的作用,最主要的作用是冷却散热。在一定范围内,随着供气压力的增加,轴承腔内温度明显降低,冷却效果明显;随着润滑油粘度的升高,轴承腔温度先下降后升高,存在最佳的润滑油粘度。(4)随着入口数目的增加,轴承腔内温度分布变化明显。在供气量一定的情况下,拥有两个入口的轴承腔内温度情况最好。同时注意到当入口增多时,轴承腔内温度相对均匀,高温区域减少。因此,增加入口数量的同时适当加大供气量可以达到更好的效果。通过与实验数据的对比,数值分析结果与实验结果基本一致。该研究成果为角接触球轴承油气润滑系统设计及最佳润滑参数的确定提供了一种有效方法和参考。
[Abstract]:High-speed motorized spindle is the core functional part of high-speed machining machine tool. Angular contact ball bearing is the main supporting mode of high-speed motorized spindle. The friction heat of angular contact ball bearings in high speed operation is the main factor leading to premature failure, so good lubrication and cooling is very important to ensure the normal operation of bearings. As a new type of gas-liquid two-phase flow cooling and lubrication technology, oil-gas lubrication has become the first choice for high-speed bearing lubrication and cooling due to its excellent performance and clean and environmental characteristics. In view of this, the temperature rise of oil-gas lubricated two-phase flow in angular contact ball bearing is analyzed. Based on the theory of bearing heat generation, the heat generation mechanism of angular contact ball bearing under the condition of oil and gas lubrication is analyzed, and the heat generation rate and convection heat transfer coefficient of the bearing under different conditions are calculated. The geometric model of 7006C angular contact ball bearing cavity is established, and the temperature field is numerically analyzed by using Fluent from six aspects of rotational speed, oil supply, gas supply pressure, lubricating oil viscosity, inlet position and inlet number. The results show that: (1) the high temperature region in the bearing cavity is mainly distributed in the area where the rolling body is in contact with the raceway, which is caused by the friction heat in the contact area and the stirring heat of lubricating oil, and the temperature in the oil and gas inlet region of the bearing cavity is relatively lowest. (2) with the increase of rotational speed, the temperature in the bearing chamber increased significantly, and the temperature increased more and more, and with the increase of the oil supply, the temperature in the bearing chamber first decreased and then increased. There is an optimal amount of oil supply. (3) compressed air is not only the transfer of oil in oil and gas lubrication, but also cooling and heat dissipation. In a certain range, with the increase of gas supply pressure, the temperature in the bearing chamber decreases obviously, and the cooling effect is obvious; with the increase of the viscosity of lubricating oil, the temperature of the bearing chamber decreases first and then increases. The optimum viscosity of lubricating oil exists. (4) with the increase of inlet number, the temperature distribution in the bearing chamber changes obviously. In the case of a certain amount of gas supply, the bearing chamber with two entrances is the best temperature condition. At the same time, it is noticed that the temperature in the bearing chamber is relatively uniform and the high temperature region is reduced when the inlet is increased. Therefore, increasing the number of imports while properly increasing the amount of gas supply can achieve better results. By comparing with the experimental data, the numerical analysis results are basically consistent with the experimental results. The research results provide an effective method and reference for the design of oil and gas lubrication system of angular contact ball bearing and the determination of optimum lubrication parameters.
【学位授予单位】：兰州理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TG502.3

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