水润滑可倾瓦推力轴承设计与性能分析

Design and performance analysis of water-lubricated tilting pad thrust bearing

针对无轴轮缘驱动推进器对高承载、长寿命、低噪音水润滑推力轴承的需求,设计了一种阶梯橡胶垫支撑的水润滑可倾瓦推力轴承;应用流-固双向直接耦合分析方法,建立了轴承性能计算模型,研究了橡胶垫基体厚度、阶梯厚度、阶梯厚度比、阶梯宽度比和瓦面材料对推力盘轴向位移、最大水膜压力与水膜厚度的影响。研究结果表明:在载荷不变的情况下,推力盘轴向位移和橡胶垫最大应力与橡胶垫厚度和橡胶垫阶梯宽度比成正比;阶梯厚度比由2/2变成3/6时,最大水膜压力由1.10 MPa提高到1.32 MPa,平均水膜厚度由9.4μm增大到14.0μm,增幅分别为20.00%和48.94%,平均水膜厚度随最大水膜压力的增大而增大;橡胶垫阶梯厚度比为2/4,阶梯宽度比为16/20~20/16时,轴承综合性能较为理想;增大推力瓦面材料的弹性模量,有利于提高轴承的润滑性能,橡胶垫最佳阶梯宽度比随之增大。

Aiming at the demand of shaft-less rim-driven thruster for high-load capacity,long-life and low-noise water lubricated thrust bearing,a step type rubber cushion-supported and waterlubricated tilting pad thrust bearing was designed.By applying the fluid-solid two-way direct coupling analysis method,the performance calculation model of bearing was established,and the influences of base rubber cushion thickness,step rubber cushion thickness,step rubber cushion thickness ratio,step width ratio and thrust pad surface material on the axial displacement of thrust disc,maximum water film pressure and water film thickness were studied.Analysis result shows that when the load is constant,both the axial displacement of thrust disc and the maximumstress of rubber pad are proportional to the rubber cushion’s thickness and the step rubber cushion’s width ratio.When the thickness ratio changes from 2/2 to 3/6,the maximum water film pressure increases from 1.10 MPa to 1.32 MPa,the mean film thickness increases from 9.4μm to14.0μm,and the increase ratios are 20.00%and 48.94%,respectively.The mean film thickness increases with the increase of the maximum water film pressure.When the step rubber cushion’s thickness ratio equals 2/4 and the step width ratio is 16/20-20/16,the overall performance of the bearing is ideal.The increase of elastic modulus of thrust pad surface material is beneficial to improve the lubrication performance of the bearing,and the optimum step rubber cushion’s width ratio increases accordingly.