Design of an ironless voice coil actuator with a rectangular coil and quasi-Halbach magnetization

Abstract – This paper describes the modeling and design of an ironless actuator with quasi-Halbach magnetarrays. The design of this actuator must find a balance between force, low dissipation, amplifier limits andvolume requirements. Several analytical and semi-analytical modeling techniques are combined to accuratelyderivethemostimportantelectromechanicalandelectricalproperties. Anoptimizationroutineisthenemployedto obtain a maximize the actuator performance within the given constraints. Introduction Voice coil actuators are a workhorse in many industrial and commercial applications as these linearactuators provide high performance and reduced cost and volume. The most common form of this typeof actuators is the cylindrical voice coil actuator, such as often seen in e.g. speakers. This paper focusesonanactuatortopologywitharectangularandrelativelyflatcoilwheretheairgapsarehorizontalinsteadof vertical. This actuator can exhibit a single airgap above or below the coil [1–3] or exhibit an airgapon both sides [4] as is shown in Fig. 1. Because the coil moves freely through the permanent magneticfield, this actuator is also referred to as voice-coil actuator or Lorentz actuator.