基于TFSI的水润滑尾轴承润滑性能研究

发布时间：2018-10-09 08:45

【摘要】：尾轴承作为船舶推进系统极其关键的设备之一,起着支撑尾轴和螺旋桨的重要作用。根据润滑介质不同,尾轴承一般可以分为油润滑和水润滑两种。船用油润滑尾轴承存在着结构复杂、滑油泄漏污染和振动噪声等缺点,而采用水润滑则可以很好地避免这些问题。但是由于水的粘度低,导致水润滑橡胶尾轴承的承载能力小的缺点。另一方面,由于橡胶材料是一种高弹性、非线性、耐高温能力较差的材料。着眼于橡胶材料的缺点,有必要开展水润滑橡胶轴承的结构-热-流三场的耦合研究,以提高尾轴承的润滑性能。这对于延长轴承使用寿命,减振降噪,实现“绿色航运”具有重要的理论意义和工程应用价值。文中以水润滑橡胶轴承周向截面为研究对象,应用大型有限元ADINA方法对水润滑尾轴承弹流动压润滑问题进行了数值分析,揭示了其润滑规律,探讨了轴承的结构形式和运行工况对其润滑性能(轴承压力分布、轴承温度分布、摩擦系数等)的影响规律。主要的研究成果如下： (1)建立了船舶水润滑橡胶轴承的平面CSD、CFD和TFSI模型,其中包括流体与固体之间耦合面的定义和热场的设定与控制。 (2)水润滑橡胶轴承的最大压力随水槽宽度的增大有下降趋势,随橡胶层厚度的增加而增大,轴承最大压力随轴承间隙的增大而减小,当轴承间隙小于或等于1mm时,轴承最大压力下降较快,而轴承间隙大于1mm时,轴承最大压力趋于平稳,变化不大；最高温度均随轴承水槽宽度增大而下降明显,随橡胶层厚度的增加而增加,随轴承间隙的增大而减小。 (3)水润滑橡胶轴承最大压力随偏心率的增大而增大,但并非是存在一个线性的关系,而是在偏心率小于0.6以前压力上升比较缓慢,当偏心率大于0.6后,压力变化的幅度加大,温度最大值随偏心率的变化曲线基本和压力分布最大值曲线相似；轴承的最大压力随偏位角的增大而减小,但是减小的幅度很小,轴承的最大温度变化也有相类似的变化。 (4)当转速在400r/min以上时的弹性流体动压润滑的情况下,轴承的最大压力和最高温度均随转速的增加而增大；改变轴承的轴向流速,轴承的压力分布基本不变；轴承最大压力与最高温度随轴承工作的水域温度的增加而增大。 (5)通过在尾轴承台架试验表明：在弹性流体动压润滑的情况下,轴承的摩擦系数较小。同时,随着轴转速的提高,轴承的摩擦系数先下降,后有小幅度的增加。润滑出水管处的温度随轴转速的增大而升高,但是升高的幅值较小。
[Abstract]:As one of the most important equipments in ship propulsion system, stern bearing plays an important role in supporting stern shaft and propeller. According to the lubricating medium, the tail bearing can be generally divided into oil lubrication and water lubrication. Marine oil lubricated tail bearings have some disadvantages such as complicated structure, oil leakage pollution and vibration noise, which can be avoided by water lubrication. However, because of the low viscosity of water, the bearing capacity of water lubricated rubber tail bearing is small. On the other hand, because rubber material is a kind of high elasticity, nonlinear, low resistance to high temperature. Considering the disadvantages of rubber materials, it is necessary to study the structure-heat flow coupling of water-lubricated rubber bearings in order to improve the lubricating performance of tail-bearing. It has important theoretical significance and engineering application value for prolonging bearing service life, reducing vibration and noise, and realizing "green shipping". Taking the circumferential section of water-lubricated rubber bearing as an object of study, the flow pressure lubrication problem of water-lubricated tail bearing is numerically analyzed by using large-scale finite element ADINA method, and the lubrication law is revealed. The influence of bearing structure and operating conditions on its lubricating performance (bearing pressure distribution, bearing temperature distribution, friction coefficient, etc.) is discussed. The main research results are as follows: (1) the plane CSD,CFD and TFSI models of marine water-lubricated rubber bearings are established, including the definition of coupling surface between fluid and solid and the setting and control of thermal field. (2) the maximum pressure of water-lubricated rubber bearing decreases with the increase of flume width, increases with the increase of rubber layer thickness, and decreases with the increase of bearing clearance. When the bearing clearance is less than or equal to 1mm, When the bearing clearance is larger than 1mm, the maximum bearing pressure tends to be stable, and the maximum temperature decreases obviously with the increase of bearing flume width, and increases with the increase of rubber layer thickness. It decreases with the increase of bearing clearance. (3) the maximum pressure of water-lubricated rubber bearing increases with the increase of eccentricity, but not with a linear relationship, but with the pressure rising slowly before eccentricity is less than 0.6. When the eccentricity ratio is greater than 0.6, the range of pressure change increases. The maximum temperature curve with eccentricity is basically similar to the maximum pressure distribution curve, and the maximum pressure of bearing decreases with the increase of offset angle, but the amplitude of decrease is very small, and the maximum temperature change of bearing is similar. (4) when the rotational speed is above 400r/min, the maximum pressure and temperature of the bearing increase with the increase of the rotational speed, and the pressure distribution of the bearing is basically unchanged when the axial velocity of the bearing is changed. The maximum bearing pressure and maximum temperature increase with the water temperature of the bearing working. (5) the test on the tail bearing bench shows that the friction coefficient of the bearing is small under the condition of elastohydrodynamic lubrication. At the same time, with the increase of shaft speed, the friction coefficient of bearing decreases first, then increases slightly. The temperature of lubricating outlet pipe increases with the increase of shaft speed, but the amplitude of increase is smaller.
【学位授予单位】：武汉理工大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH133.3

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