Experimental Verification of Thrust Improvement in Voice Coil Linear Actuator Using Combined Wire of Copper and Iron

The linear motor is a direct-drive structure, which means that no mechanism for thrust expansion, such as a gear mechanism, can be applied. In a linear electromagnetic actuator, the thrust follows the iBl rule, and so the magnetic flux density of the winding space or the magneto-motive force (mmf) of the armature winding must be large to obtain the large thrust. If the mmf is designed to be large, the size of the linear motor must be large. In this paper, a novel armature winding method using a combined wire of copper and iron with high permeability is proposed. The capability of the combined wire of copper and iron to enlarge the thrust of the motor without increasing its volume is examined. It was clarified experimentally that the thrust of the tested voice coil linear actuator using the combined wire is improved.