Design of a class of wide-angle limited-rotation rotary actuators

Abstract

Two design methods are presented for a doubly-excited, doubly-salient, concentrated-winding type of limited-rotation double-acting rotary actuator employing natural air cooling. The first is based on specified values of current density and magnetic flux density, and the second (a development of the first) uses experimental data relating winding temperatures to I2R losses. A synthesis procedure is described that uses the second method for a family of actuators of different continuous torque, peak torque and aspect ratio. Curves are presented that show the variation of important design parameters with aspect ratio and scale. The use of forced convection cooling is suggested as a way of improving the performance/volume ratio of larger actuators.