High torque density magnetorheological brake with multipole dual disc construction

This paper presents a magnetorheological (MR) brake with the intent of overcoming the problems of limited torque density and low manufacturability that conventional MR brakes come across. Firstly, the conceptual design of the proposed MR brake was finalized. High torque density was achieved by using the combined effect of the dual disc-type construction and multipole concept. High manufacturability was attained with a simple and lightweight mechanical construction. It was created with the major components, namely magnetically permeable stator cases, rotor discs, magnetic cores, winding coils, and MR fluid. The computer aided design (CAD) model and analytical models were also developed to study the performance of the proposed brake. Then, the dimensions of the brake were optimized through electromagnetic simulations. Further, the brake performance was simulated using a three-dimensional electromagnetic model. Finally, a prototype of the optimized MR brake was fabricated, and its performance was experimentally validated. It is clear from the computer simulations and experimental test results, that the proposed MR brake has achieved the objective. The maximum torque was 16.5 Nm, and the torque density of 79.3 Nm dm⁻³ was significantly higher than that of conventional MR brakes. This brake also exhibited a fairly rapid response with a response rate of 90 ms.