Electrorheological fluid force transmission and conversion device

Abstract

An electrorheological fluid torque transmission and conversion system provides for variable control of torque in clutch and brake applications. Communication of mechanical energy between the drive elements is accomplished by magnetic coupling to eliminate the need for a dynamic fluid seal for interface of moving parts to the interior portion of the electrorheological fluid containment chamber. Permanent magnets are associated respectively with each of a first member and a second member which are magnetically coupled through a surface with low magnetic permeability such that the first member and second members rotate in unison. A variety of permanent arrangements may be utilized. Further, the drive element internal to the electrorheological fluid chamber may be both mechanically and electrically decoupled. A floating electrode may be capacitively coupled through the fluid to the power supply. Also provided are inner and outer conductive plates are provided for increased fluid surface contact area. Spacing between the inner and outer plates is determined by the thickness of inner and outer ring members therebetween, which may be easily removed and replaced for simplified assembly and adjustment. Condition responsive control of the electrorheological fluid torque transmission and conversion system is provided by closed-loop feedback of a signal indicative of rotational speed between the drive elements to the control system. The control system may also incorporate internal power generation to provide a self-contained system which does not require an external power source.