Simplified thrust limit equation of linear DC motor

In this paper, examination of the limiting value of the thrust constant of a linear DC motor (LDM) is described. The LDM under consideration is a moving coil unipolar type. We deduce a relation between the limiting value of the thrust constant LDM and the dimensions of the yokes. By comparison of the measured thrust and the magnetic field analysis (finite element method), the validity of the thrust constant limit equation is confirmed. The thrust constant limit equation qualitatively agrees with the observed result, and its maximum error is 26.0 percent. It also agrees well with the result of the magnetic field analysis.