Semi-active Control Of Seal Fluid Excitation Based On Magnetorheological Damper And Active Vibration Control Of Tool Machine

Rotating machinery may have vibration fault due to various causes in the running process.The vibration fault will cause downtime,explosion and other serious accidents,which can cause great economic losses and casualties.Therefore,it is of great importance to study the effective vibration reduction technology and control the vibration of rotating machinery in the process of operation.In this paper,the vibration control method of seal fluid excitation and milling machine and lathe were studied.Magnetorheological damper,a new type of damper,was used combined with PID control program,realizing the semi-active control of seal fluid excitation in the sealing clearance.The vibration data of milling machine and lathe were monitored and the influence of three machining parameters on machine tool vibration was studied by orthogonal experiment.The Active damping device(Active Damper Device,or ADD)was used to actively control vibration of milling machine spindle and lathe tool holder.The main research contents are summarized as follows:(1)A model of rotor-seal system was established.The critical speed and vibration mode of the system were theoretically calculated.Comparison of rotor axis trajectories theoretically proved that applying damping can reduce the vibration of the rotor-seal system.A vibration control experiment platform was built up,with the magnetorheological damper installed in proper place.Using PID control method,the seal fluid excitation was controlled with good control effect.(2)A milling machine vibration control experiment platform was built up,and the vibration data in the process of machining was monitored.Designed the appropriate orthogonal table and analyzed the influence of three machining parameters on the milling machine spindle vibration.(3)The active damping device was used to control milling machine spindle vibration.In the whole process,the first half process didn't exert control and the second half process exerted control.The contrast of vibration data in different processes showed that this method can significantly inhibit and actively control the spindle vibration of milling machine.(4)9 sets of orthogonal experiments were conducted,and the surface roughness of the work pieces was measured.Comparison of the machining precision in different conditions showed that the vibration control of the spindle can reduce the surface roughness of the work piece and improve the precision.(5)A lathe vibration control experiment platform was built up,and the vibration data in the process of machining was monitored.Designed the appropriate orthogonal table and analyzed the influence of three machining parameters on the lathe tool holder vibration.(6)The active damping device was used to control lathe tool holder vibration.The contrast of vibration data in different conditions showed that this method can significantly inhibit and actively control the lathe tool holder vibration,and can improve the precision.