Study On Temperature Field Characteristics And Fatigue Life Of Roll Ring

The roll ring is a rotating electrical transmission device,which is often used to transmit current and signal between relative rotating mechanisms.Because it adopts the form of rolling electrical contact friction pair,it rarely produces friction and wear,and has the characteristics of low contact resistance,high transmission efficiency and long service life.The flexible ring is the core component of the roll ring,and its compression amount is directly related to the electrical contact performance and fatigue life.It is of great significance to study the temperature field characteristics and fatigue life for determining the compression amount,which provides a reference for the engineering design of the roll ring.In this thesis,a highspeed roll ring device is designed based on the research background of the fan confluence ring.A fatigue life calculation method for obtaining stress curve by transient dynamics analysis is proposed.The virtual prototype,static and dynamic characteristics,temperature field characteristics and fatigue life are analyzed.The main research contents are as follows:(1)Structure design and virtual prototype simulation of roll ring.A new type of roll ring device is designed.According to the kinematic analysis model,the motion relationship between the conductive inner ring,the conductive outer ring,the spoke flexible ring and the idle wheel is clarified.Based on the analysis of pure rolling motion,the size of pure rolling friction pair is calculated,the dynamic model of multi-body system is established,and the virtual prototype simulation of roll ring is carried out to verify the rationality of the size design of pure rolling friction pair.(2)Static and dynamic characteristics analysis of roll ring.The finite element model is established,and the static analysis is carried out for different compression amounts of the spoke flexible ring to clarify the relationship between the maximum Mises stress and the compression amount.Through the transient dynamic analysis,the stress curve with time under different compression amounts is obtained,which provides calculation data for the fatigue life simulation calculation.The first six natural frequencies and vibration modes are obtained by modal analysis of the whole roll ring.(3)Analysis of temperature field characteristics of roll ring.The calculation model of contact resistance is established,and the relationship between contact resistance and compression amount is obtained.The contact resistance heat,rolling friction heat and convective heat transfer coefficient are calculated.The influence of the transmission current,the compression amount of the spoke flexible ring and the number of the spoke flexible ring on the temperature field characteristics of the roll ring is analyzed.The results show that the temperature is positively correlated with the transmission current and the number of the spoke flexible ring,and negatively correlated with the compression amount of the spoke flexible ring.The thermal-mechanical coupling analysis is carried out by sequential coupling method,and the influence of temperature on the mechanical properties of spoke flexible ring is obtained.(4)Fatigue life analysis of roll ring.Based on the transient analysis stress curve,combined with the S-N curve and the Goodman average stress correction method,the number of stress cycles of the spoke flexible ring under different compression amounts is calculated.The results show that when the compression amount of the spoke flexible ring is 0.8 mm,the fatigue life design index and electrical contact performance requirements can be met at the same time.In summary,this thesis studies the mechanical properties,temperature field characteristics and fatigue life of the roll ring,and determines the appropriate compression amount of the spoke flexible ring,which has certain guiding significance for the engineering design of the roll ring.