振动离心复合试验系统中空气弹簧隔振系统设计

振动离心复合试验系统是将电动振动台或压电激振器安装在离心机转臂末端的设备,对于振动台顺臂振动,为了避免过大的激振力对离心机主轴及传动系统造成损坏,在转臂与转臂支承之间安装空气弹簧隔振系统。利用刚体动力学方法,建立了振动离心复合试验系统的数学模型。指出隔振系统必须具有变载荷对中能力。最后,考虑空气弹簧工作在压缩状态、考虑转速对系统刚度的影响,对隔振系统特性进行分析。分析表明,在转臂系统初始位置质心偏离时,空气弹簧刚度随着离心机转速增加而增大。空气弹簧刚度应足够大以抵消离心机转速影响,避免系统发散。

Design of Air Spring Vibration Isolation System of Combined Acceleration and Vibration Environment Simulator

Combined acceleration and vibration environment simulator is a kind of equipment the end of whose arm mounted a electrodynamic shaker or piezoelectric actuators. For shaker along arm direction, in order to avoid damage to principal axis and transmission system of centrifuge caused by overlarge exciting force, a kind of air spring vibration isolation system was mounted between centrifuge arm and supporting structure. Mathematical model of acceleration and vibration environment was built using rigid body dynamics method. The concept that the vibration isolation system must have variable load centering technique was put forward. Finally, the characteristics of vibration isolation system was analyzed considering compressive status of air spring and influence of rotation rate on the system stiffness. The results showed that the stiffness of air spring increased along with the increase of centrifuge rotation rate, when barycenter of arm offset. In addition, the stiffness of air spring should be high enough to compensate the influence of rotation rate, to avoid system divergency.