Abstract
Recently, various types of a magnetic actuator have been developed. The actuator has to be designed to satisfy the specification of the thrust, the stroke, the size and so on.
In the automobile industry, the size of a solenoid actuator can be reduced by improving the coil configuration and the magnetic-circuit form without decreasing the thrust. The thrust, however, is not evaluated systematically.
This paper proposes a new disk-type multipolar solenoids and analyzes the thrust by using the finite element method. The calculated values show a good agreement with the experimental ones. For a short stroke range with a high-magnetomotive-force excitation, the colenoid confignration is appropriate, and for a long stroke a usual solenoid excitation is useful. In a practical stroke range of 0.2_??_0.3mm, however, the multipolar solenod has a comparatively large thrust.
Furthermore, the colenoid configuration can yield a fast response of the movement because the acceleration of the actuator increases with the number of the coils.
