摘要
超声悬浮技术可以实现悬浮和减摩功能,减少转子与静子之间的摩擦,而且由超声波产生的悬浮力可以不受悬浮物材料的影响.首先,根据流体动力学推导出超声波挤压膜的基本方程,对其进行理论推导并利用高阶差分方法进行仿真求解;针对气膜力与悬浮间隙、超声波振幅、气压、超声波频率因素的关系进行了分析,讨论了不同参数对超声悬浮性能的影响规律.然后,通过平面气膜力分解与合成推导出凹面气膜力,并研究了转速对其悬浮力的影响.将其施加在不平衡转子系统中,对转子系统的振动响应进行数值仿真,并对各个情况下的结果进行对比,探讨出不同参数下的振动抑制效果.最后,设计了超声悬浮-转子系统的实验台,通过实验测试不同参数下转子系统的振动响应,验证超声悬浮技术对于转子系统的振动抑制作用.
Ultrasonic suspension technology has the function of suspension and friction reduction, which can reduce the friction between the rotor and the stator, and the suspension force generated by the ultrasonic wave can be free from the suspension material. Firstly, according to the fluid dynamics, the basic equations of the ultrasonic extrusion film were deduced. The force of the ultrasonic extrusion film was deduced theoretically and numerically solved by the high-order difference method. The relationship between film force and suspension gap, ultrasonic amplitude, air pressure and ultrasonic frequency was analyzed. Effects of these parameters on the ultrasonic suspension performance were discussed. Then, the suspension force of the concave ultrasonic gas extrusion film was obtained by plane extrusion film force decomposition and synthesis. The effect of rotating speed on the suspension force of concave extrusion film was studied. The suspension force of the ultrasonic squeeze film was applied to the unbalanced rotor system, and the vibration response of the rotor system was numerically simulated. The results of each case were compared to explore the vibration suppression effect under different parameters. Finally, an experimental platform for the ultrasonic suspension-rotor system was designed and built. The vibration responses of the rotor system with different parameters were tested to verify the vibration suppression performance by using the ultrasonic suspension technology.
引文
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