Optimized design and three-dimensional (3-D) finite element analysis of a rotary actuator

Automotive vacuum actuation systems are being replaced by electromechanical actuators. Extremes of temperature and fluctuating voltage supply complicate the use of electrical apparatus in such applications. Minimal cost and continuous duty operation constraints drive the optimization process. The design and analysis of a variable reluctance rotary actuator is presented for 12-V automotive applications. A simple linear model is used for optimization of the magnetic coil dimensions. Fringe effects and nonlinear magnetics are modeled with a three-dimensional (3-D) finite element model. Output torque computed with the model is compared to prototype device test results. The effects on different steel grades are examined.