非均匀磨损水润滑橡胶轴承的润滑特性

Lubrication properties of water-lubricated rubber bearings with non-uniform wear

针对船用水润滑橡胶轴承在非均匀磨损情况下的润滑特性,首先给出非均匀磨损情况下磨损区域的几何模型,在综合考虑橡胶衬层磨损和弹性变形的情况下建立水润滑橡胶轴承的弹流润滑模型,然后基于有限差分法离散雷诺方程并采用逐次超松弛迭代法求解水膜压力,分析非均匀磨损对水润滑橡胶轴承润滑特性的影响。结果表明:非均匀磨损使轴承的水膜厚度从轴承的前端(磨损厚度最小)到轴承尾端(磨损厚度最大)逐渐增加;水膜压力峰值相应地从轴承的前端到轴承尾端逐渐降低。水膜压力峰值发生的位置和水膜破裂的位置均延后,并且在轴承尾端延后的角度较大。在相同偏心率的情况下,随着最大磨损厚度增加,水膜合力(即承载力)、偏位角和摩擦力均减小。在相同载荷情况下,随着最大磨损厚度增加,轴颈的偏心率增加。发生非均匀磨损后水膜速度不再关于轴承中间截面对称分布,水膜合力的作用位置向轴承前端偏移,同时产生一个较小的附加合力偶,合力作用位置的偏移量随着最大磨损厚度和偏心率增加而增加。

The lubrication properties of water-lubricated rubber bearings for ships under non-uniform wear are studied.Firstly,the geometric model of non-uniform wear area is presented.The elastohydrodynamic lubrication model of water-lubricated rubber bearings is established considering both wear and elastic deformation of rubber liner.Then,the Reynolds equation is discretized by finite difference method and the water film pressure is solved by successive over-relaxation iteration method.The influences of non-uniform wear on the lubrication characteristics of water-lubricated rubber bearings are analyzed.The results show that the non-uniform wear makes the water film thickness increase gradually from the front end of the bearing where the wear thickness is minimum to the rear end where the wear thickness is maximum.Correspondingly,the peak pressure of water film decreases gradually from the front end to the rear end.The position of the peak pressure and the position where water film ruptures are both delayed,with the delay angles at the rear end of the bearing larger.Under the same eccentricity ratio,the water film resultant force(i.e.bearing capacity),attitude angle and friction force decrease with the increase of maximum wear thickness.Under the same load,the eccentricity ratio of the journal increases with the increase of the maximum wear thickness.After non-uniform wear,the water film flow velocity is no longer distributed symmetrically about the middle section of the bearing.The action position of the water film resultant force shifts to the front end of the bearing.At the same time,a small additional resultant force couple is generated.The offset of the action position of resultant force increases with the increase of maximum wear thickness and eccentricity ratio.