Development of a novel planar actuator

Abstract

Planar motors, also named surface motors, x-y motors or two-dimensional linear motors, can be used in applications that require movement on a plane in two directions (x-y axes), e.g. movers of semiconductor waffles, printed circuits, and pieces machined by numerically controlled machines. The use of electronic control systems allows motion of that sort with accurate position detection and rapid response without loss of steps or position deviation. This paper depicts a new planar actuator with novel structure and construction features. Many research centres are involved in the development of surface motors usually based on the Sawyer motor topology. The novel planar actuator analysed by this work has quite different characteristics in its structure: a stationary slotless armature with orthogonal windings; and a mover with two high-energy product NdFeB permanent magnets. Owing to its topology, the planar actuator develops movement over a plane surface. It results from the interaction between the magnetic flux and current established through the orthogonal multiphase windings that comprehend the armature circuit. The actuator was analysed by means of the finite element method in order to compute the forces involved and improve its design. The results are presented in this paper.