FIGURE 6 Schematic of a magnetic brake/clutch to display its operation. (a) Magnetic particle clutch. (b) Input shaft “R” and output shaft “N” are positioned within the electromagnetic coil. Magnetic particles lay loosely between input and output components. No current is applied to the coil. No torque is transmitted. (c) Here maximum current energizes the coil. The clutch now operates at 100% of clutch rating. Full transmission of torque occurs. Depending on coil current, any level between 0 and 100% torque transmission is possible. (Courtesy Magnetic Power Systems, Inc., Fenton, MO.)

ABSTRACT

By forming the IM from a magnetically hard material (one that resists a change in magnetization as indicated by a small value of µ) which also has a large area enclosed by the hysteresis loop, the manufacturer can assure relatively large losses in the brake. The

energy extracted from the input shaft in this manner heats the IM, which must be cooled to maintain the performance of the brake.