The Analysis of Magnetorheological Brake Structure with Multiple Poles

Magnetorheological (MR) brake is broadly applied in various fields. As the increase in demand of bicycle training equipment, this paper introduces a MR brake with multiple poles and outer rotor structure, which can be used as resistant source for bicycle-training equipment. With outer-rotor structure, the MR brake is suitable to use as a roller to fit the bike rear wheel on. The equipment is specifically designed for indoor exercise for users with their bikes. Magnetic circuit of the MR brake was built and analyzed. Key factors to affect brake torque were found. After that, two structures of the MR brake with different pole number were simulated to find the optimal one to harmonize between maximum output torque and input power. The simulation results confirm the feasibility of the designed MR brake. With compact design, its braking performance is enough to be use on bicycle-training equipment.