Volumetric improvements in high energy magnet motors

Key selection criteria for servo motors are size, weight, and performance. Only high energy permanent magnet motors meet all three. However, if low cost is the only goal, it is possible that motors not using permanent magnets could be selected for many applications. Development of high energy permanent magnet materials during the last two decades has provided many opportunities for advancement in servo motor design. The constant interface of magnet producers and users has enhanced the value of the motor product. To look at the overall picture, items such as continuous and peak torque, speed range, weight, strategic material usage, and cost must always be evaluated. The normalized data will show that higher energy product magnets offer substantial performance advantages but often cost more than lower energy product magnets. As a result of NdFeB development, this cost gap is likely to be closed while maintaining the high performance edge. Considering high performance market requirements, motors using the new family of materials continue to show the appeal of high energy motor products. This paper will cover applications of these types of materials and values of products derived.