基于不同热边界条件的斜面轴承及阶梯轴承承载性能分析

Numerical Analysis on Load Carrying Capacity of Inclined Bearings and Step Bearings under Different Thermal Boundary Conditions

为探讨滑块轴承的承载特性,针对两类经典的推力滑块轴承,即斜面轴承和阶梯轴承,建立考虑润滑剂热效应的流体动力润滑模型。使用多重网格法求解压力场,在最高层网格上使用逐列扫描法求解温度场,得到相应的数值解。分别基于两组热边界条件:(一)静止表面绝热而运动表面保持常温;(二)静止表面保持常温但运动表面绝热,来分析对比斜面轴承和阶梯轴承的承载性能。研究表明:热楔效应是产生承载力的原因之一,事实上两类轴承承载能力的大小皆由几何楔和热楔的叠加效应决定:几何楔效应弱时,热楔效应占主导,此时第(二)组边界条件下两类轴承有更好的承载性能。

For two kinds of typical thrust pad bearings,namely,inclined bearing and step bearings,the mathematical models of hydrodynamic lubrication considering the thermal effect of lubricants were developed.The multi-grid method was used to solve the pressure field,and the column-by-column relaxation scheme was used to solve the temperature field only on the finest grid.Based on two groups of thermal boundary conditions:(1)the stationary surface is adiabatic yet the moving surface maintains ambient temperature;(2)the stationary surface maintains ambient temperature yet the moving one is adiabatic,the load carrying capacity of these two typical thrust bearings was compared and analyzed.Results show that thermal wedge contributes to their load carrying capacity definitely,in fact the carrying capacity is determined by the combined effects of geometric wedge and thermal wedge.It is also found that thermal wedge effect plays the dominate role when geometric wedge effect is weak,therefore,the thrust pad bearings would achieve higher load carrying capacity under the second thermal boundary condition.