A study for high force giant voice coil motor

Abstract

A kind of electromagnetic actuator, voice coil motor is widely used for precision motion systems, since it has a simple structure, non-contact force generation and a good linearity between force output and electric current input. But it usually shows small force compared to other types of actuators. In this paper it is described how the generated force of the conventional voice coil motor can be enhanced. Increase of the generated force is related to the volumetric expansion of the voice coil motor and its expanding direction with respect to the direction of the generated force. The limitation of the conventional type of voice coil motor, in view of high force generation, is illustrated and a new type of voice coil motor is introduced which has a different way of volumetric expansion for high force generation. The conventional one can expand only one direction, but the new one can expand every direction. This feature gives the designer flexible use of space and high force generation. A giant voice coil motor is developed adopting the new structure showing force generation of 574 N at current of 3.44 A.