The Key Parameters Of The Crankshaft Magnetorheological Torsional Vibration Damper Are Matched And Optimized

Engines are very common in life,from aerospace,mining,transportation,ships,industrial assembly lines,large-scale manufacturing to everyday life cars,can see engine-related applications.Shafting torsional vibration is a vibration mode occurs in the operation of the rotor system,and it is also a relatively common form of vibration during engine shafting operation.Severe torsional vibration will greatly reduce the working efficiency of the engine,and even lead to fatigue damage of the engine shaft train or other transmission structures.The conventional vibration damping method is to install a torsional vibration damper at the shaft end,but with the rapid development of industry,the engine is gradually developing towards high speed and high power,the traditional fixed damping shock absorber has gradually been unable to meet the needs of actual production development.The Magnetorheological torsional vibration damper has gradually attracted attention because of its advantages such as controllable damping,rapid response and simple control,and good compatibility with crankshaft torsional vibration.This variable damping shock absorber can achieve optimal vibration damping for each critical speed in the working range of the engine,and can adjust the vibration damping parameters according to the changes in the working conditions of the crankshaft system,which is of great significance to the torsional vibration of the shaft system.However,so far,the research on magnetorheological torsional shock absorbers for crankshaft systems is still in the exploration stage,and there is a lack of more complete design concepts and methods in the design of magnetorheological damping torsional shock absorbers.Based on this,this paper adopts the research method of theoretical modeling combined with simulation and experiment,and takes a certain engine as the research object to study the matching design method of shafting magnetorheological torsional shock absorber.Firstly,according to the relevant parameters of the engine and shafting structure,carried out the kinematics and dynamic analysis of the torsional vibration condition of the crankshaft system.Then,established the discrete model of the crankshaft system and carried out the free vibration and forced vibration analysis of the model by using the system matrix method,obtained the natural frequency and mode,dangerous speed,and torsional amplitude of the engine under the corresponding working conditions.Secondly,established a simple dual-mass torsional model of shock absorber and shafting system,analyzed the design theory and design method that are more practical in the design of torsional vibration damper,studied the influence of torsional vibration related parameters in the shock absorber on the torsional vibration of the system,derived the calculation method of the best damping coefficient in pure damping shock absorber,obtained the characteristic curve of the damping torsional vibration absorber.Then,in order to provide reference for the matching design of magnetorheological torsional shock absorber,proposed three different configurations of magnetorheological torsional shock absorber structures,established the magnetic circuit model,mechanical model and dynamic response time model of the shock absorber.Provided the optimization methods in different directions,compared the performance between magnetorheological torsional shock absorbers of different configurations,studied the determination method of equivalent damping of magnetorheological torsional shock absorbers under torsional vibration conditions,which provides ideas for the design of subsequent magnetorheological torsional shock absorbers.Finally,according to the torsional vibration analysis of the engine shaft system,the analysis of the relevant parameters of the torsional vibration damper and the optimization design method of the magnetorheological torsional vibration damper,proposed a matching design method of magnetorheological torsional vibration damper suitable for the engine shaft system,completed the design of the magnetorheological torsional shock absorber of a certain engine.Then,by using the planetary gear train combined with eccentric mass block,built a shaft system torsional vibration experimental platform,and through simulation analysis and corresponding experimental comparison,analyzed the change of shaft torsional vibration after the shaft system was equipped with fixed damping torsional vibration damper and variable damping torsional vibration damper.The results show that the magnetorheological torsional shock absorber can achieve good vibration damping for multiple resonant speeds of the shaft system,and also verify the effectiveness of the matching design method of the crankshaft magnetorheological torsional vibration damper proposed in this paper.