Novel magnetorheological brake with self-protection and water cooling for elevators

摘要

This study aims to design a magnetorheological (MR) brake with self-protection and heat dissipation functions for elevators. Using permanent magnet system technology, the MR brake can not only form a double magnetic field with excitation coils to improve braking torque under normal operation but also provide braking torque for protection in case of power failure. In addition, a cooling channel is designed in the braking shaft of the MR brake to ensure effective heat dissipation of the MR fluid. In this work, the structure, material, and magnetic circuit of the MR brake is first developed. Then, finite element, magnetic field, and thermal field analyses are conducted on the brake. Finally, a prototype of the brake is produced, and its performance is tested. Results show that the braking torque, especially the self-protection function, meets the demands of the elevator; the increase in temperature during braking is minor; and the noise level is low.