A new coil configuration of a linear DC motor to improve thrust

Abstract

The purpose of this study was to develop a linear DC motor capable of generating greater thrust. A new type of coil configuration consisting of magnetic and non-magnetic wires was proposed. The magnetic wire enhances the magnetic flux density in the magnetic circuit, and the non-magnetic wire controls the direction of magnetic flux in the magnetic wire. Electric current is applied to the magnetic wire.
The software simulation showed that the averaged magnetic densities of the magnetic wire and of nonmagnetic wire, just above the magnet, were 0.615T and 0.075T, respectively. The thrust of the linear DC motor improved approximately 30% comparison with the conventional linear DC motor consisting of copper wired coil only at the same power supply.
The measured thrust of the prototype linear DC motor showed approximately 80% against the estimated thrust because of differences between the analysis model and the actual form.
Suitable width ratio between the magnetic wire and the non-magnetic wire, and reasonable clearance between outer diameter of coil and inner diameter of outer yoke were estimated.