Design and realization of a PM linear synchronous motor with a very high thrust/normal force ratio

An important drawback in PM linear synchronous motor applications is the high normal force (compared to the thrust developed by the motor itself) due to the stator-cursor magnetic attraction. A new linear motor with a very high thrust/normal force ratio has been designed and a prototype has been constructed. The motor is a PM linear synchronous motor with the PMs mounted on an ironless cursor. The motor performance have been evaluated in terms of generated forces (thrust and normal force) considering the values obtained by simulations and laboratory tests. Laboratory generated forces measurements have been performed by an "ad hoc" instrumentation described in the paper itself.