轴偏斜工况下米歇尔式推力轴承润滑性能分析

Lubrication Performance Analysis of Mitchell Thrust Bearing under Shaft Misalignment Conditions

采用多瓦联合仿真方法,对某一轴偏斜的船用米歇尔式推力轴承进行稳态润滑和瞬态润滑分析,分别得出各瓦块稳态润滑参数的分布和随轴偏斜量的变化规律、阶跃载荷作用时各瓦块瞬态润滑参数的变化规律。结果表明:瓦块倾角的变化量与轴偏斜数量级相当,为不影响油膜建立,支撑结构应保证瓦块在轴偏斜时能自由摆动;轴偏斜工况下,推力盘偏向一侧的推力瓦块承载力加大,油膜温度升高、油膜厚度变小,而推力盘偏离一侧的推力瓦块承载力降低,油膜温度降低、油膜厚度变大;随轴偏斜角度增加,瓦块润滑参数差别加大;阶跃载荷作用后,各瓦块润滑参数在极短的时间内发生突变。较小的轴偏斜量对推力轴承工作安全性产生严重影响,提高推力轴承的轴偏斜补偿能力具有重要意义。

By using united simulation method of multi-pads,steady-state and transient-state lubrication analysis was carried out on one marine Mitchell thrust bearing under shaft misalignment conditions. The parameters distribution of steadystate lubrication and the parameters＇ changing rule according to the shaft misalignment as well as the transient response of the lubrication parameters under a step load condition were acquired separately for each pad. The results show that the titling angle of the pads changes within the orders of magnitude of the shaft misalignment,and the supporting structure should guarantee that pads could still tilt freely to ensure the formation of oil film. Under the shaft misalignment condition,the load and the oil film temperature of the pads that closed to the thrust collar are increased,while the oil film thickness is decreased. The load and the oil film temperature of the pads that stayed far from the thrust collar are decreased,while the oil film thickness is increased. The difference of lubricating parameters of pads is increased along with increasing of tilting angle of shaft misalignment. When a step load is applied,the lubricating parameters of each pad changes in a very short time. The small amount of shaft misalignment causes safe operation of the thrust bearing deteriorated seriously,and it is of significance to improve the misalignment compensation ability of the thrust bearings.