Tran Hai NAM
The Journal of Mechanical Science and Technology, vol. 23, no. 7, pp.1911-1923, 2009

Abstract : A generated resistance force in the deformation process is considered to increase the resistance torque of a Magneto- Rheological (MR) brake when a variable stiffness material is rolled under the cylindrical form of a roller. This paper proposes a new approach to increase the resistance torque of an MR brake using a large-size magnetic particle which can be considered as the roller mentioned above (steel roller or rolling pin). Due to the cylindrical form of the roller and a line contact between the roller and the surface of the motion part, the steel roller can contribute to create a stronger magnetic field and larger resistance force than the conventional one. In this paper, a new MR brake is successfully designed to generate a higher braking torque than the conventional one, which only uses typical MR fluid. To verify the effect of the roller, the proposed MR brake is compared with the conventional one. Both of the MR brakes are designed with the same magnetic circuit and the same material parameters. The performance of the proposed MR brake is compared with that of the conventional MR brake. The proposed MR brake is verified to have about 200% larger torque than the conventional one.

Keyword : MR brake; MR fluid; Small steel roller; Braking torque; Functional fluid