Design of Magnetorheological Brake using Parabolic Shaped Rotating Disc

Abstract

The aim of this paper is to enhance the braking torque of a magnetorheological brake (MRB) system. The proposed brake system consists of rotary disc with wave form boundary immersed in a MR fluid and enclosed in an electromagnet. The yield stress of the fluid varies as a function of magnetic field created by electric current passing through the electromagnet. The instantaneous increase in yield stress of fluid significantly increases the friction on the surfaces of rotating disks; thus generating a retarding braking torque. Due to the waveform boundary, a wedge shape is formed between the outer fixed casing and the disc. This wedge shape provides the extra resisting force to stop the rotation of the disc due to the shear stress of the MR fluid changed with the influence of the applied magnetic field. In the present study, the Bingham model has been used to estimate the braking torque exercised by MR brake. A parametric study considering various configurations of rotating disk and MR gap has been presented. Parabolic profile MR brake shows the large braking torque compared to circular profile of disc.