静压孔位置对油膜支承可倾瓦轴承承载性能的影响分析

为了提高汽轮机转子系统中支承轴承的油膜刚度，以三瓦油膜支承可倾瓦轴承为研究对象，研究静压孔相对位置对轴承承载性能的影响规律。建立了油膜支承可倾瓦轴承油膜润滑模型，并运用计算流体动力学方法数值求解三维N-S方程，揭示了不同静压孔相对位置下轴承压力分布、最小膜厚、偏心率、刚度等性能参数的变化规律。分析结果表明：在载荷为890 N的情况下，改变孔的位置可以提高轴承油膜刚度；当静压孔相对位置γ=5°左右时，孔位置接近油膜最大压力分布区，与γ=0°时相比，最小膜厚和偏心率分别减小9.8%和48%，主刚度kyy、kxx接近原结构的1.4倍和1.1倍，此时静压孔位置为相对最优位置区域。依据分析结果开发了新型油膜支承可倾瓦轴承（γ=5°），通过试验对比分析了普通滑动轴承与新型油膜支承可倾瓦轴承的综合性能，结果表明，高转速时所开发的新型油膜支承可倾瓦轴承具有更好的承载性能与减振性能。研究结果对油膜支承可倾瓦轴承的性能分析具有一定的参考价值，设计轴承静压孔时可根据油膜压力分布规律对其优化以提高轴承性能。

Influence Law of Relative Position of Static Pressure Holes on Bearing Capacity for Fluid Pivot Tilting Pad Bearing

In order to improve the oil film stiffness of the supporting bearings in the steam turbine rotor systems， the influence law of the relative position of static pressure hole on the bearing capacity is studied by taking the three-pad fluid pivot journal bearings as the research object. The oil film lubrication model of the fluid pivot tilting pad bearing was established， and the three-dimensional Navier-Stokes equations numerical solution was carried out on CFD， revealing the variation law of bearing pressure distribution， minimum film thickness， eccentricity， stiffness and other performance parameters at different relative positions of static holes. The analysis results show that the stiffness of bearing oil film can be improved by changing the position of the hole under the load of 890 N； when the relative position of the static pressure hole=5°， the hole position is close to the maximum pressure distribution area of oil film the principal stiffness， the minimum film thickness and eccentricity are reduced by 9.8% and 48% respectively， compared with γ=0 °， kyy and kxx are close to 1.4 times and 1.1 times of the original structure， the static pressure hole position is relatively optimal at this time. Based on the analysis results， a new type of fluid pivot tilting pad bearing （γ=5°） is developed. The comprehensive performances of the common sliding bearings and the new type of fluid pivot tilting pad bearings are compared and analyzed by experiments. The results show that the new type of fluid pivot tilting pad bearings has better bearing capacity and vibration reduction performance at high rotating speed. This study has certain reference value for the performance analysis of the fluid pivot tilting pad bearings. According to the distribution law of oil film pressure， the design of bearing static pressure holes may be optimized to improve bearing performance.