超声悬浮式陀螺的结构设计及悬浮特性分析

Investigation on Structural Dynamic Design and Suspending Characteristics of Ultrasonic Levitation Type of Gyros

为了改善陀螺的支承系统,减少支承摩擦力矩以提高陀螺的综合性能,提出采用超声近场悬浮作用来提供浮子式陀螺的支承,分别构造了圆筒和圆盘式振动结构来提供足够的超声辐射,由此形成的近场声辐射压力对圆筒型浮子组件进行支撑和定位。其中,圆筒型定子的驻波振动诱发声辐射力提供沿浮子径向的悬浮支承,圆盘式端盖的驻波振动提供沿浮子轴向的定位支撑,可在圆筒式浮子与筒式定子和端盖之间的间隙中形成振动的挤压气膜,由此产生的分布式声辐射压力可为悬浮物提供稳定的支撑。首先,阐释了超声悬浮式陀螺的工作机理和结构组成,对圆筒和圆盘式定子进行了结构动力学分析和设计;其次,针对振动结构开展了多物理场耦合分析,研究了悬浮特性的影响因素;最后,加工制造了样机,搭建了实验平台并测试了其悬浮特性能力。结果表明,采用近场声悬浮机理的超声悬浮陀螺定子完全能够悬浮起要求的浮子。

Supporting style has important effect upon output accuracy of mechanical rotor gyros,and various kinds of suspending technology are investigated to improve the supporting system of rotor gyros.It is expected that integration of gyros can be enhanced by reducing the friction torque of supporting structure. In this paper a non-contact bearing based on near-field acoustic levitation(NFAL)is proposed for supporting pattern of gyros.The vibrating cylindrical and circular structures are designed to provide enough acoustic filed,and the resulting levitation force can levitate and position the float of gyros.In this case acoustic radiation force induced by standing wave vibration of the cylindrical stator provides radial levitation supporting for the float.Meanwhile air gap due to the vibrating circular plates is formed and the distributing acoustic radiation force presents an axial position support.First working principle and configuration of the ultrasonic levitation type of gyros are presented,and structural dynamics analysis and design are carried out for the cylindrical and circular stators.Then multi-physical filed coupling analysis for the vibration stators is conducted in order to study the levitation characteristics.Finally aprototype is manufactured, and the experimental system is built up to measure he levitation characteristics of the prototype.Moreover it is experimentally proved that the stators of ultrasonic levitation type of gyros based on NFAL mechanism can suspend the expected float well.