Structure Design And Performance Research Of Magnetorheological Brake

With the advance of automotive engineering, vehicle speed increases gradually, so the brake safety requirements are also rising, and the discretion of the brake safety depends entirely on the stand or fall of brake performance. At the same time, intelligent degree of car electronic control device change with each passing day, related automotive mechanical system is easy to implement integration intelligent to become extremely important, hence the magnetorheological brake was born. Magnetorheological fluid is a kind of smart material controlled by plus magnetic field, which can achieve in a flash transformation from the free flow of liquid to solid with the action of magnetic field. The rheological properties of the magnetorheological fluid characteristic makes it especially suitable for braking areas. The exciting current control can realize the vehicle braking in continuous,real-time, fast and accurate, and easy to realize automatic and intelligent.Due to the limitation of MRF material performance and space, magnetorheological brake often faces the problem of insufficient braking torque when used in high power machinery brake situation. To achieve the automation and intelligent of the high power vehicle braking within the limited space, a dual disc MR brake which works in shear mode was designed, which increase braking torque through the contact areas.In this paper, the development progress of MRF material and the present situation of magnetorheological device are summarized, the mechanism of magnetorheological effect in macroscopic and microscopic was expounded, and introduction about the composition and working mode of MRF was given. Article completed the design of the mechanical structure of magnetorheological brake is based on the mechanical properties; then magnetorheological brake magnetic circuit design was finished according to the special requirements for the mechanical structure and braking torque. Magnetic field simulation was carried out by using ANSYS software for the magnetic circuit of brake. Simulation model was established by using SIMULINK simulation toolbox, studied structure parameters and operating conditions how affect the performance of magnetorheological brake. Finally, the heat dissipation of magnetorheological brake was analyzed.Simulation results show that the designed magnetorheological brake heat dissipation conditions and braking torque can meet the requirements, the braking torque has good liner relationship of working current in a certain range. It’s easy to develop linear control system.The maximum braking torque can reach 1025.42 mN ? when the exciting current is 3A,the maximum temperature rising of the brake was 33℃ in braking. It will not cause significant effect on the performance of magnetorheological brake; meanwhile it can meetthe demand of the selected vehicle braking.