A0Class Small Pure Electric Vehicles MRF Brake Structure Design And Performance

Magnetorheological fluid (Magneto-rheological Fluids, MRF) is a new kind ofintelligent materials. MRF can be instant, continuous and reversible rheological in themagnetic field, in addition, it can be real-time active controlled. Through thereasonable structure design and magnetic circuit current control with thecharacteristics of magnetorheological fluid, it can be applied to the automobile brakingsystem and achieved rapid, continuous change, so it achieves the aim of control ofbraking torque according to the actual needs. Because the development of the electriccar, the cancellation of the engine braking system can’t satisfy the vacuum sourcecondition, the need to increase the vacuum pump to extract the vacuum source, is morecomplex to the arrangement of the vehicle and the matching, MRF brake and canrealize full electric control, solve the problems of the electric vehicle braking system.MRF brake and compared with the traditional mechanical friction brake, has goodcontrol performance, fast response and low energy consumption etc, so the study ofMRF brake conforms to the developing direction of the cars of the future, so the studyof MRF brake conforms to the development direction of the cars of the future, it needto be studied.Based on the analysis of MRF performance and operation modes of MRF, putforward the two kinds of MRF brake structure: drum and disc type. With introducingthe works of cylinder and disc type of MRF brake, and calculating two kinds of braketorque, through comparative analysis the advantages and disadvantages of two kinds ofbrake, determined the MRF brake structure form which is suitable for this article.Calculate the main structure parameters of MRF brake of MRF brake and magneticcircuit design, finally, completed the overall structure scheme of MRF brakearrangement and draw the MRF brake general structure diagram. According to MRFbrake braking torque formulas, brake the braking torque model was established, MRFbrake mechanical properties are analyzed in the simulation by using Matlab/Simulink software.Through simulation analysis can be seen that the influences with differentstructure sizes of brake torque, it is concluded that the maximum braking moment ofMRF brake. After some brake design improvements, MRF brake braking torque canmeet the basic brake performance demands of A0-class small electric cars. Theresearch results can provide theoretical references for the further study of MRF brake.