阶梯槽织构对水润滑止推轴承静态特性的影响

Effect of Stepped-Groove Texture on the Static Performances of Water-lubricated Thrust Bearings

目的研究非对称性阶梯槽织构对水润滑止推轴承静态特性的影响。方法首先建立考虑表面织构、紊流以及JFO空化模型的Reynolds方程,再采用有限差分法求解方程,得到织构化轴承的压力分布以及剪应力;然后对压力以及剪应力沿轴承表面积分,求得轴承的承载力及摩擦力;最后研究不同转速以及结构参数下阶梯槽织构对水润滑止推轴承承载力及摩擦力的影响规律。结果若阶梯槽织构为前槽深、后槽浅,且当前、后槽槽宽相等时,承载力存在最大值;对于前槽浅、后槽深的织构,当前、后槽槽宽相等时,承载力最小。当前槽槽深小于水膜间隙,后槽槽深约为0.67倍的前槽槽深时,轴承承载力最大;当前槽槽深大于水膜间隙,后槽槽深约为0.33倍的前槽槽深时,轴承承载力最大。当前槽槽深不大于水膜间隙(15μm)时,存在使摩擦力最小的最佳槽深比;当前槽槽深大于15μm时,随着前后槽深比从0.33增大至1.68,轴承摩擦力逐渐减小。结论阶梯槽织构起到了减小水润滑止推轴承摩擦力的效果。将阶梯槽设计为沿水流方向前槽深、后槽浅,且前、后槽槽宽相等,可以得到较大的承载力。合适的阶梯槽表面织构参数能够实现大承载、低摩擦。

The work aims to investigate the effects of unsymmetrical stepped-groove texture on the static performances of water-lubricated thrust bearing.Firstly,the turbulent Reynolds equation considering surface texture,turbulence and JFO cavitation model was established,and then solved by Finite Difference Method to calculate the pressure distribution and viscous shear stress of textured bearing.Secondly,the load capacity and friction force were obtained by integration of the pressure and viscous shear stress over the bearing surface,respectively.Finally,the influences of the stepped-groove texture on the load capacity and friction force at different rotary speed and parameters were investigated.For the stepped-groove texture with deep front groove and shallow rear groove,the load capacity was the largest when the width of front groove was equal to that of rear groove.However,for the texture with shallow front groove and deep rear groove,the load capacity reached the minimum when the width of front groove was equal to that of rear groove.When the depth of front groove was smaller than the water film thickness and the ratio of rear groove depth to front groove depth was about 0.67,the load capacity of bearing reached the maximum.When the depth of front groove was greater than the water film thickness and the ratio of rear groove depth to front groove depth was about 0.33,the load capacity of bearing reached the maximum.There was an optimal ratio of rear groove depth to front groove depth for the minimum friction force when the depth of front groove was smaller than the water film thickness(15μm).However,when the depth of front groove was greater than 15μm,the friction force gradually decreased as the ratio increased from 0.33 to 1.68.The stepped-groove texture can reduce the friction force of the water-lubricated thrust bearing.To obtain a great load capacity,the front groove should be deeper than the rear groove along the flow direction,but the width should be the same.Proper design of parameters of the stepped-groove texture can provide a large load capacity and lower friction force.