Performance Testing And Design Of Magnetorheological Fluid Brake With Adjustable Gap

Magneto-rheological fluid is a controllable intelligent material,whose dynamic yield stress behaves the characteristics of linear the continuous variable,reversible and responses fast.Therefore,it is ideal material for developing the new linear controllable brake.Magneto-rheological fluid consists of numerous micro particles with high relatively magnetic permeability and some kind of oil-based fluid with low hysteresis ferromagnetic.It presents Newtonian fluid characteristics in the absence of magnetic field conditions,while when the magnetic field added it behaves a half solid liquid or solid state.Based on the excellent mechanical properties of MRF,it can be applied to the devices that require additional magnetic field control,such as magnetic rheological clutch,damper and transmission device,etc.Through it has reported a lot of researches on magneto-rheological brake in the past few years,there are still many problems unsolved,therefore,it is still extremely significant to continue the correlate research.Based on the disc MRF brake proposed,this paper launched some in-depth researches as follow:First of all,based on the references in the related yield,mechanism and the rheological property of MRF was expounded systematically with the main factors influenced on the braking performance was summarized simultaneously.Secondly,optimizing the parameters of magneto-rheological brake for better performance magneto-rheological brake was built on the magneto-rheological braking torque equation established by the Bingham model.In reality,the brake always has a irregular structure.For this reason,this paper presents a new braking torque calculation methods using Ansys and Matlab data fitting simultaneously to evaluate the real torque at the extreme.Again,a magneto-rheological brake test was fitted for the agneto-rheological brake.The braking torque under different currents and different gaps was measured.Compared with conventional braking torque calculation methods,the proposed new calculation methods based on simulation results presents more accurate and practical.Finally,this paper suggested some measures for improving the performance of the MRF brake.Several kinds of disc surfaces was tested to study their influences on braking torque eventually.