海水淡化泵水润滑轴承试验测试与分析

为了研究不同转速下水润滑轴承动压润滑效果和系统稳定性,依据海水淡化泵的结构特点,设计了水润滑轴承试验台.基于试验对水润滑轴承周向压力分布及轴心轨迹进行监测分析,同时采用刚体求解方法对轴心涡动轨迹进行数值模拟计算,并将试验结果与数值模拟结果进行对比验证.结果表明:低转速时,楔形间隙内润滑介质水较少,水膜压力分布不连续且压力值较低,各监测点的压力曲线不稳定;随着转速的增大,润滑介质水增多,流体动压润滑效果增强,水膜承载效果增强,压力分布与压力曲线开始趋于稳定,表明整个轴承-转子系统开始趋于稳定;同时,随着转速的增大,液膜厚度增大,轴颈涡动振幅增大,涡动中心明显上移,试验实测结果与CFD模拟计算结果一致,验证了采用数值模拟来研究轴承-转子系统动力学特性有一定的借鉴和参考价值.

Test and analysis of water-lubricated bearing of seawater desalination pump

In order to study the hydrodynamic lubrication performance of the water-lubricated bearing and the stability of the system at different rotating speeds, the water-lubricated bearing test rig was designed based on the structure of desalination high-pressure pump. The fluid-structure interaction analysis of the bearing-rotor system was conducted by the Rigid Body Method. The journal orbit and bearing pressure fluctuations were monitored in the test, and the numerical simulation was conducted to verify the journal whirling orbit. The results show that there is a little lubrication water in the wedge gap,and the water film pressure is not stable and its distribution is discontinuous at a low rotating speed. With the rotating speed increasing, the lubrication water will increase, and the hydrodynamic effect will enhance, while the pressure distribution and curve will tend to be stable, indicating that the bearing-rotor system becomes stable. With the increase of rotating speed, the thickness of water film and the journal whirling amplitudes increase, and the journal whirling center lifts obviously. By comparing the result of numerical calculation with data from the test, the numerical calculation is proved to be a useful way to analyze the dynamic characteristic of the rotor-bearing system.