Design And Research Of Online Dynamic Balancing Device Driven By SMA

With the development of modern industry,rotating machinery is developing towards high speed,precision and automation.High speed rotor often produces vibration due to unbalance.In order to effectively suppress the vibration caused by unbalance in rotor operation,online dynamic balancing technology is very important.Shape Memory Alloy(SMA)is a kind of intelligent material which can ' remember ' the initial shape.It is widely used in modern industry,medicine and other fields because of its unique shape memory effect and superelasticity.In this paper,the mechanical properties and electrothermal driving mechanism of SMA were studied by using SMA composed of NiTi material as a driving component and applying it to a new type of dynamic balancing terminal.The purpose of online vibration suppression of high-speed rotor system is realized by designing SMA-driven online dynamic balancing device starting from the way of dynamic balancing terminal driving counterweight.This paper mainly studies the dynamic balancing device based on SMA driving counterweight.The main contents are as follows :Firstly,the shape memory effect and driving mechanism of SMA are studied,and the mechanical properties of the coil spring SMA are studied;Because the shape memory effect of SMA depends on the temperature change,the relationship between temperature,deformation and mechanics of SMA spring is studied,and the deformation model of SMA spring is obtained;The model of electric heating of SMA spring under the effect of current and heat is studied.Secondly,according to the basic theory of rotor dynamic balancing,an active dynamic balancing device driven by SMA spring to adjust the unbalance is designed,and the counterweight provided by the counterweight mass in the dynamic balancing device is analyzed in detail;The counterweight efficiency of the dynamic balance device is analyzed.The mechanical characteristics of the dynamic balance device in the application state are analyzed and calculated to ensure the safety and reliability of the device structure.Finally,the driving characteristics of SMA spring under current thermal effect are studied by experiment and theoretical fitting;The counterweight efficiency of dynamic balancing device driven by SMA spring is analyzed experimentally;Based on the characteristics of dynamic balancing device,the control strategy of dynamic balancing device driven by the whole system is studied;The experimental platform of rotor dynamic balance is built,and the dynamic balance experiment is carried out,which verifies the effectiveness of the dynamic balance device.In general,a new type of dynamic balancing device is designed in this paper,and the effectiveness of the dynamic balancing device is verified by experiments.The dynamic balancing device is simple in structure and easy to control,which provides technical support for the implementation of online dynamic balancing of rotating machinery.