Stress-strain Analysis And Design Optimization Of Push Rod Of Vacuum Circuit Breaker

The electromagnetic operating mechanism of vacuum circuit breaker needs a lot of operating work in the process of opening and closing,and this process will produce a great impact on the key parts of the mechanism,and the mechanical life of these parts in the mechanism may be greatly shortened.Based on this situation,this thesis modeled the electromagnetic operating mechanism of vacuum circuit breaker and analyzed its dynamic characteristics and fatigue life in the process of opening and closing.The specific research work is as follows:Firstly,this topic puts forward the research background and significance of studying the dynamic characteristics of the electromagnetic operating mechanism of vacuum circuit breaker,analyzes the research status of the operating mechanism of vacuum circuit breaker,and makes a more detailed introduction in the dynamic research status of the operating mechanism of vacuum circuit breaker.Then,according to the fatigue life analysis methods of large mechanical components in the current academic field,the fatigue life analysis methods and research difficulties for the electromagnetic operating mechanism of vacuum circuit breaker are put forward.Then,according to the working principle of the electromagnetic operating mechanism of vacuum circuit breaker,the dynamic simulation principle of the electromagnetic operating mechanism of vacuum circuit breaker is determined;According to the actual working conditions of the electromagnetic operating mechanism of vacuum circuit breaker and the analysis of various fatigue types of mechanical structure,it is determined that the fatigue type of the electromagnetic operating mechanism of vacuum circuit breaker is high cycle fatigue.Aiming at this form of fatigue life,the nominal stress method which is more suitable for it is selected as the research means of this thesis.Secondly,according to the relevant knowledge of electromagnetism,the displacement time curve and the received electrodynamic change curve of the moving iron core of the electromagnetic mechanism during opening and closing are analyzed in Ansoft Maxwell;Based on the knowledge of rigid flexible coupling multi-body dynamics,the rigid flexible coupling dynamics analysis model of electromagnetic operating mechanism is established in ADAMS,and the displacement time curve and load spectrum of the key component push rod of the operating mechanism in the process of opening and closing are obtained and analyzed.Then,according to the relevant knowledge of structural dynamics,the finite element structural dynamics performance analysis of the electromagnetic operating mechanism of the circuit breaker is carried out by using ANSYS Workbench,and the stress distribution of each component of the electromagnetic operating mechanism of the circuit breaker in the process of opening and closing is analyzed,as well as the modal main vibration mode corresponding to the first ten natural frequencies of the key component push rod,which provides basic data for the subsequent fatigue life analysis of the push rod.Finally,taking the push rod,the key component of the electromagnetic operating mechanism of vacuum circuit breaker,as the research object,the fatigue life and safety factor of the push rod under normal working conditions are simulated and analyzed by using professional software.According to the calculation process of the above analysis,this thesis provides a relatively complete calculation method from dynamic analysis to fatigue life check.This method can also be extended to the stress analysis and fatigue life check of other parts of the electromagnetic operating mechanism of the circuit breaker,which has strong practical value.