1992 Volume 112 Issue 1 Pages 45-54
In development and design stage of electromagnetic actuator, two methods for magnetic field analysis are mainly used for the optimal design. One is a method based on magnetic equivalent circuit. But it is unsuitable for the accurate calculation because of leakage flux and nonlinearity in the magnetic circuit. On the other hand, nonlinear magnetic field analysis using Finite Element Method (FEM) has been widely used as a powerful and useful means in recent years. Since it requires a large sized computer for the calculation, it is mainly used for the large sized devices and hardly used for the small ones.
In this paper, we use FEM to study the optimal design for the electromagnetic actuator, from the view of the generation of electromagnetic force. A plunger type solenoid which is widely used in practical use is analyzed to realize more compact shape and suitable characteristics of force. Consequently, it can be made clear how the shape of main air-gap, the saturation in yoke, and the lapping length between movable core and yoke affect the characteristics of the force. Further, it is demonstrated that each parameters can be used to get the optimal design.