Abstract:

To effectively overcome the shortcomings of conventional air bearings,a new style squeeze film air bearing was developed according to the ultrasonic wave suspension and air squeeze film.In order to get the size and the control parameter,the modal analysis and the harmonic response analysis of the piezoelectric ceramic actuator used in the bearing were carried out by the finite element method.The capacity of the bearing was given by using numerical solution methods theoretically.The working frequency of the piezoelectric ceramic actuator was determined by the modal experiments.Also,the ultrasonic sound pressure which produced by bearing was analyzed by means of finite element method.On this basis of above,a digital controller adopting STC single chip micyoco(SCM) and incomplete differential PID control strategy was developed and actual operation of the system was also carried out.The results show that the capacity of the bearing is determined  theorelically.And what the bearing with ultrasonic vibration may have levitation force is proved through experimental method.

Key words: squeeze film air bearing, finite element method, levitated support, incomplete differential PID

摘要：

为了有效克服传统气体轴承的缺点,基于超声激励的气体挤压膜机理，研制了一种新型的气体挤压膜轴承。为了获得关键结构尺寸及相关的控制参数，采用有限元法对压电换能器进行了模态分析和谐响应分析;应用数值解法从理论上证明了轴承的悬浮能力;通过压电换能器的模态实验,确定了其工作频率;同时采用有限元法对所设计的轴承产生的超声波声压进行了分析。在此基础上,设计制作了基于STC单片机的数字控制器硬件电路，编写了不完全微分PID控制程序并在实验台上进行了验证。研究结果表明,该类轴承在超声激励下能够实现悬浮支承。

关键词: 气体挤压膜轴承, 有限元法, 悬浮支撑, 不完全微分PID