Design optimisation of a novel slotless linear stepping motor

A new brushless and slotless DC linear motor employing a movable set of NdFeB-type magnets is proposed. Its design was optimised to achieve a large force to volume ratio. Due to its unique topology, it can be used as a linear stepping motor. The model of the motor and its optimisation procedure were developed on the initial assumption that the magnetic circuit is linear. After being assembled, the motor had its flux density at specific points and the static force along the travel length measured. A 3D finite element analysis of the flux distribution of the motor was carried out. The assessment of the analytical, numerical and measured values shows a very good correlation among them. The results are presented and discussed in this paper