Optimization design and braking performance analysis of cylindrical magnetorheological brake with inner and outer fluid flow channels

Abstract To solve the problem of low magnetic field utilization of traditional magnetorheological (MR) brakes, a cylindrical MR brake with inner and outer fluid flow channels was proposed in this paper. By adding non-magnetic device to the rotating sleeve and cylinder, the magnetic flux lines meandered through six effective damping gaps in the inner and outer axial flow channels, allowing the MR brake to achieve better braking performance without changing its external dimensions. The structure and working principle of the cylindrical MR brake were depicted, and a magnetic circuit analysis was also carried out. In the meantime, the mathematical models of the braking torque and the temperature field were deduced. The simulation analysis of multiple physical fields of the MR brake was carried out using COMSOL software. The magnetic flux density and the distribution of the magnetic flux lines within the brake were obtained using a steady-state electromagnetic field simulation. The internal temperature distribution of the MR brake under different braking conditions was determined using a transient temperature field simulation. The current response time and the magnetic field response time considering the eddy current condition were obtained using a transient electromagnetic field. The experimental results show that when the applied current was 2.0 A, the braking torque and dynamic adjustable range were 44.28 N·m and 17.88, respectively. Compared to the simulation values of 47.35 N·m and 21.31, the errors between the two are 6.5% and 16.1%, respectively.