基于FLUENT的水润滑尾轴承冷却润滑性能研究

发布时间：2019-01-04 14:25

【摘要】：橡胶是一种高弹性材料,其吸振性和加工性能、以及抗磨粒磨损、腐蚀磨损和疲劳磨损性能良好等优点,因此广泛作用在水润滑尾轴承的内衬。但是,由于水的粘性比较低、沸点低,船舶在低速重载或者启停瞬间轴承的运行工况比较恶劣,轴承的冷却效果比较差,目前还没有相关研究能够很好地解决此类问题。为改善水润滑尾轴承的冷却性能,优化轴承的结构、提高轴承的使用寿命,文中主要通过尾轴承摩擦学性能试验,进行轴承速度特性和温度特性研究,并利用gambit前处理器软件建立水润滑橡胶尾轴承的CFD模型,在不考虑轴承材料受温度影响变化的情况下,应用FLUENT软件计算分析了轴承结构参数(轴承开槽形式、水槽宽度、水槽个数、开槽形式、水槽深度)、尾轴倾斜和轴承运行工况(轴的转速、轴承轴向流速)对轴承水膜压力和轴承温度的影响状况,得到如下结论： (1)摩擦学性能试验结果。对凹面型尾轴承进行了速度-摩擦因数和温度特性试验。速度-摩擦因数曲线形状与经验Stribeck理论曲线相似,验证了水润滑轴承试验数据是可信的,为后续章节的计算提供相关数据；温度特性试验表明比压越大摩擦因数越小,在一定范围内轴转速越大,摩擦因数越小。 (2)尾轴承的结构参数对冷却效果的影响。通过一系列不同流速下轴承温度的对比发现,全开槽轴承冷却效果明显优于半开槽轴承。半开槽轴承高温区域比较大,但水膜支撑力明显大于全开槽轴承,因此,在满足冷却效果的前提下,应尽量减少轴承下半部水槽数量。水槽宽度在一定范围内对轴承冷却效果有影响,水槽越宽,轴承温度越低,但是效果不明显。一般情况下,水槽个数越多轴承的温度越低。水槽形式对轴承影响不大；半圆形水槽略优于U形水槽。水槽深度对轴承冷却效果有明显影响。 (3)尾轴由于受螺旋桨悬臂作用,产生倾斜,导致轴承摩擦加剧,水膜生成困难,轴承温度也随之升高。不同水域与季节会导致尾轴承冷却水温度大不相同。当冷却水初始温度比较高时,轴承温度会相应升高。轴承在不同转速不同冷却水流速下,轴承的温度相差很大。低转速低入口流速时,轴承温度相对比较高,相对高转速高入口流速时,轴承温度相对较低。
[Abstract]:Rubber is a kind of high elastic material, its vibration absorption and processing performance, as well as wear resistance, corrosion wear and fatigue wear performance are good, so it is widely used in the liner of water lubricated tail bearing. However, due to the low viscosity of water and the low boiling point, the operation condition of the bearing at low speed and heavy load or at the moment of starting and stopping is relatively bad, and the cooling effect of the bearing is relatively poor. At present, there is no relevant research to solve this kind of problem well. In order to improve the cooling performance of the water lubricated tail bearing, optimize the structure of the bearing and increase the service life of the bearing, the speed and temperature characteristics of the bearing are studied mainly through the tribological performance test of the tail bearing. The CFD model of water-lubricated rubber tail bearing is established by using gambit pre-processor software. Without considering the influence of temperature on bearing material, the bearing structural parameters (bearing slotted form, flume width) are calculated and analyzed by FLUENT software. The influence of the number of flume, the form of slot, the depth of the flume, the tilting of the tail shaft and the operating condition of the bearing (the rotating speed of the shaft, the axial velocity of the bearing) on the bearing water film pressure and bearing temperature, The following conclusions are obtained: (1) tribological performance test results. The velocity-friction coefficient and temperature characteristics of concave tail bearing were tested. The shape of the velocity-friction coefficient curve is similar to that of the empirical Stribeck theory curve, which verifies that the experimental data of water-lubricated bearing are reliable, and provides relevant data for the calculation of subsequent chapters. The temperature characteristic tests show that the larger the specific pressure the smaller the friction coefficient and the greater the axial speed in a certain range the smaller the friction coefficient. (2) the influence of the structure parameters of the tail bearing on the cooling effect. It is found that the cooling effect of the full slotted bearing is better than that of the semi-slotted bearing through a series of comparison of bearing temperature at different velocities. The high temperature region of semi-slotted bearing is large, but the water film support force is obviously larger than that of fully slotted bearing. Therefore, under the premise of satisfying the cooling effect, the number of flume in the lower half of the bearing should be reduced as far as possible. The width of the flume affects the cooling effect of the bearing in a certain range. The wider the sink, the lower the bearing temperature, but the effect is not obvious. In general, the more the number of tanks, the lower the temperature of the bearings. The form of flume has little effect on bearing, and the semicircular flume is a little better than U-shaped tank. The depth of the tank has a significant effect on the cooling effect of the bearing. (3) because the shaft is inclined by the propeller cantilever, the friction of the bearing is aggravated, the water film is difficult to form, and the temperature of the bearing increases. Different water areas and seasons will lead to different cooling water temperature of tail bearing. When the initial temperature of cooling water is relatively high, the bearing temperature will rise accordingly. Bearing temperature varies greatly under different speed and different cooling water velocity. At low speed and low inlet velocity, the bearing temperature is relatively high, and the bearing temperature is relatively low at relatively high speed and high inlet velocity.
【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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