滚动轴承跨音速绕流喷油润滑油液穿透机理研究

发布时间：2018-03-23 12:09

本文选题：滚动轴承　切入点：喷油润滑　出处：《河南科技大学》2017年硕士论文

【摘要】：随着科技的进步,高速机床和航空航天发动机技术在不断的发展,滚动轴承作为这些机械的关键零部件正在面临着高速、高温、重载等运转条件的挑战。这使其使用的性能要求日益苛刻,如何有效的润滑成为满足这些要求的重中之重。喷油润滑因具有系统简单、易控制、润滑冷却效果好等优点被大量应用在高速滚动轴承中。随着高速滚动轴承转速的提高,轴承内外圈将形成高速气流。跨音速轴承环间会出现高速绕流现象,使润滑环境变得非常复杂。为了能更有效的对跨音速轴承进行润滑,需要对跨音速轴承喷油润滑的穿透机理进行研究。本课题基于计算流体力学研究滚动轴承环间气相流场的特性,应用计算流体力学软件来模拟滚动轴承跨音速绕流喷油润滑的运动过程,探究滚动轴承跨音速绕流喷油润滑油液的穿透机理。首先,进行气相流的计算与分析,应用计算流体力学软件模拟在不同转速下轴承内部的空气流场,分析气流的速度特性和压力特性,探究阻碍油液进入的因素,为后面研究的气液两相流提供初始边界。其次,根据气相流场提供的初始边界,应用计算流体力学软件模拟在不同喷嘴角度和不同喷嘴直径下轴承内部的气液两相流场,探究喷嘴角度和喷嘴直径对喷油润滑的影响。最后,通过试验对仿真计算进行验证。研究结果表明:气相流场方面,将喷嘴放在小端面更合适;在喷嘴向下喷油时将喷嘴放在无量纲径向0.25处较合适;在向上喷油时将喷嘴设置在径向无量纲0.8处较合适;两相流方面,经过分析发现将整体模型简化为单个模型进行计算分析是可行的;在喷嘴向下喷射,喷嘴角度为30°时,油液体积分数最大,喷嘴直径在1.5mm时,油液体积分数最大。在喷嘴向上喷射,喷嘴角度为30°时,喷入轴承环间的油液体积分数最大,适当的调整喷嘴角度和喷嘴直径可以提高喷油润滑的效率;利用试验进行验证,数据的对比结果基本吻合,验证了仿真的准确性和有效性。本文通过以上分析得到了气相流与气液两相流的运动特性,揭示了滚动轴承跨音速绕流喷油润滑的穿透机理和部分阻碍因素,是轴承内部二相流形成问题的重要补充,又为改善喷油润滑的润滑效果提供更深入的理论依据。
[Abstract]:With the development of science and technology, the technology of high-speed machine tools and aeronautic and aerospace engines is developing continuously. As the key parts of these machines, rolling bearings are facing high speed and high temperature. Heavy load and other operating conditions challenge. This makes its performance requirements increasingly demanding, how to effectively lubricate the top priority to meet these requirements. Injection lubrication because of its simple system, easy to control, The advantages of good lubricating and cooling effect are widely used in high speed rolling bearings. With the increase of speed of high speed rolling bearings, the inner and outer rings of bearings will form high speed airflow. Make the lubrication environment very complicated. In order to lubricate transonic bearings more effectively, It is necessary to study the penetration mechanism of oil injection lubrication in transonic bearings. Based on computational fluid dynamics (CFD), the characteristics of gas phase flow field between rings of rolling bearings are studied. The computational fluid dynamics software is used to simulate the motion process of transonic oil injection lubrication for rolling bearings, and to explore the penetration mechanism of the oil injection fluid around the transonic flow of rolling bearings. First, the calculation and analysis of gas flow are carried out. This paper applies computational fluid dynamics software to simulate the air flow field inside the bearing at different rotational speeds, analyzes the velocity and pressure characteristics of the airflow, probes into the factors hindering the entry of oil, and provides the initial boundary for the gas-liquid two-phase flow studied later. According to the initial boundary provided by the gas phase flow field, the gas-liquid two-phase flow field in the bearing under different nozzle angles and different nozzle diameters is simulated by using computational fluid dynamics software, and the effects of nozzle angle and nozzle diameter on oil injection lubrication are investigated. The experimental results show that the nozzle is more suitable to be placed on the small end surface in the gas phase flow field, and the nozzle is more suitable to be placed at the dimensionless radial 0.25 when the nozzle is injected downwards. It is found that it is feasible to simplify the whole model into a single model for calculation and analysis when the nozzle is injected upward at a radial dimensionless 0.8; for two-phase flow, it is feasible to simplify the integral model to a single model for calculation and analysis; when the nozzle injects downward, the nozzle angle is 30 掳. When the nozzle diameter is 1.5mm, the oil volume fraction is the largest. When the nozzle is injected upward and the nozzle angle is 30 掳, the oil liquid integral number between the bearing rings is the largest. Proper adjustment of nozzle angle and nozzle diameter can improve the efficiency of fuel injection lubrication. The accuracy and validity of the simulation are verified. The kinematic characteristics of gas-phase flow and gas-liquid two-phase flow are obtained through the above analysis, and the penetration mechanism and some hindrance factors of the transonic injection lubrication of rolling bearings are revealed. It is an important supplement to the formation of two-phase flow in bearings and provides more theoretical basis for improving the lubricating effect of oil injection lubrication.
【学位授予单位】：河南科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TH133.33

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