Mechanism Analysis And Experiment Study Of MRF Coupling With Cycloid Curve

Magneto-rheological Torque Transmission Device(MRTD)refers to a kind of rotary driving device using Magneto-rheological Fluid(MRF)as working medium,which has the advantages of rapid response,is often used in the mechanical transmission system of torque transmission and vibration control.However,the traditional MRTDs are mostly based on the shear mode of MRF,it is difficult to solve the problem between the high torque transmission performance and lightweight design due to the limitations of shear mechanical properties of MRF.For this purpose,a novel MRF couplings with cycloid curve based on the magneto-rheological extrusion&shear mixed mode is proposed,which effectively use the MRF to enhance dynamic transfer torque by optimizing the magneto flux.A series of research on structural design,mechanical model and performance tests are conducted by combination of theorical analysis,numerical simulation and test.The details of the work are as follows:(1)A novel magneto-rheological fluid coupling with cycloid curve is proposed,according to analysis of the existing structure and working mode of the traditional MRF couplings,which is based on the result of electromagnetic theory and finite element simulation.On the basis of calculation method of metal rolling force based on Calman’s unit pressure differential equation,the mechanical transmission mechanism model of MRF coupling with cycloid curve is developed.The numerical simulation of the torque transmission performance of MRF couplings with planar and cycloid curve is conducted about the influence of key parameters by means of Matlab,so as to clarify the performance characteristics of the device.The results show that the torque transmission performance of the MRF coupling with cycloid curve has a certain improvement compared with the general plane MRF couplings when the ripple parameters are properly set up.(2)In view of the electromagnetics and thermodynamic properties of the MRF coupling,the finite simulation analysis has been completed.The rationality analysis of the magnetic circuit design of the corresponding two&three-dimensional finite element model is done by the finite element analysis software,results show that the magnetic field is guided by the isolation ring,the distribution of magnetic field meet the design expectations,and verify the theoretical model of electromagnetic characteristics of MRF coupling.In addition,the steady-state thermal analysis of MRF couplings is carried out from the thermodynamic point of view,and the temperature distribution of main structure and MRF under stable working condition are initially determined.(3)Experimental test on the mechanical properties of the MRF coupling prototype were carried out.The main performance characteristics of MRF couplings under different excitation currents,such as braking torque,dynamic transmission torque and viscous resistance moment,are compared.The experimental results are compared with the theoretical results to verify the validity of the theoretical model and to analyze the cause of the error.The experimental results show that the proposed MRF coupling has better mechanical performance than the traditional MRF coupling in torque output,transmission stability,synchronous response time and impact resistance.