Development of a novel magnetorheological brake with zigzag magnetic flux path

In this research work, a novel disc-type configuration of magneto-rheological brake (MRB) with zigzag magnetic flux path is proposed. In this design, a rotor component consisting of several magnetic plates integrated in a disc made of non-magnetic material is implemented. A magnetic plate is separated with the others by nonmagnetic separators of the disc. Corresponding magnetic plates and separators are also implemented on the housing of the MRB. With this configuration, the magnetic flux line is forced to cross the MR fluid (MRF) duct from the disc to the housing at this separator and then from the housing to the disc at the next separator. This results in a zigzag magnetic flux path between the disc and the housing. The separators on each side of the housing are integrated on a bobbin, on which the magnetic coil is installed. When counter currents are applied to the coils on each side of the housing, a mutual magnetic field with zigzag flux lines across the MRF duct is generated. Based on the electromagnetic finite element and torque analysis, optimization problem considering the maximum achievable braking torque and the minimum mass of the MRB is performed. After that, optimal results of the MRB are obtained and compared with those of MRBs in previous works. Based on optimal results of the MRB with a maximum achievable braking torque of 20 Nm, an MRB prototype is fabricated and experimentally investigated to validate the simulation results.