Optimal design of synchronous torque couplers

The design of synchronous torque couplers based upon the utilization of high coercive force rare-earth cobalt permanent magnets is considered. For such units, it is generally required to obtain a given torque output with a minimum volume of magnetic material, subject to whatever design constraints may exist. The maximum torque for such optimized configurations is shown to be and per unit volume of magnetic material and inner coupler element, respectively, where is the average radius in the gap of width , and Bris the remanent flux density. Examples of such optimal designs are given and possible alternate design criteria are briefly discussed.