Research Based On The Magneto-rheological Fluid Differential Damper For Compliant Polishing

Magneto-rheological fluid (MRF) is a kind of intelligent materials. Under the action of amagnetic field, MRF can transform its state between liquid and solid in split second and thetransformation is reversible. Based on this, it has been widely used in the field of mechanicalprocessing and transmission, structure vibration, medical devices aerospace and others. Magneto-rheological fluid damper (MRD) is a simple torque transfer device. The output torque of the mostMRD is difficult to control and unstable affected by the hysteresis. It generated an unfavorableeffect on the mechanical processing. Developing a new set of MRD which is more controllable andmore stable is significant for expending the MRD’s application in the field of mechanicalprocessing.In order to solve the problem above, a new Magneto-rheological fluid differential damper(MRDD) was designed. The magnetic field and magnetic flux of the MRDD was analyzed by theANSYS software. At last, the relation between the theoretical output torque and the current in thetwo coils was generated.The output torque of the MRDD was tested in order to better gain the output torquecharacteristic of the MRDD and a single MRD. The step response, the relation between the outputtorque and the speed, the relation between the torque and the current, the hysteresis test of a singleMRD were carried out.Based on the test above, the method of how to control the hysteresis of the MRD wasproposed. The relation between one current and the other current was obtained by analyzing andcalculating in theory. The program of controlling the two current was programmed.The test of the control method gained by the above analysis was carried out. Applying theMRDD device to NC machine, the compliant polishing based on the MRDD was set up. Thepressure, the polishing tool and the attitude in the polishing process were decoupled, and thepolishing theory of the MRDD was obtained. Based on this, the theory of compliant polishing laidthe foundation of compliant polishing experiment.