A magnetorheological fluid shaft seal with low friction torque

This paper deals with the design and tests of a magnetorheological fluid seal (MRFs) using the innovative concept of the magnetic circuit, which allows the achievement of a promising trade-off between burst pressure and friction of the seal. Low friction torque and low burst pressure are typical for a ferrofluid seal (FFs). Replacement of the ferrofluid by magnetorheological fluid increases the burst pressure of the seal but the friction torque of the seal increases too. The optimum for sealing application is low friction torque and high burst pressure. The presented design is based on the pinch mode of magnetorheological fluid. The geometry of the seal was determined by a magnetostatic model. Subsequently, the chosen concept of the seal was manufactured and tested. Pinch MRFs achieved lower friction torque than common (standard) MRFs and a higher burst pressure than any FFs.