Principle and Modeling of a Novel Moving Coil Linear-Rotary Electromagnetic Actuator

Tat Joo Teo, Haiyue Zhu, Si-Lu Chen, Guilin Yang, Chee Khiang Pang

Abstract: This paper presents a novel electromagnetic actuator that adopts an air-core coil mover to deliver decoupled linear and rotary motions. It uses light-weight moving coil to achieve high speed and dynamic response, and single-phase Lorentz-force driving scheme to realize direct and noncommutation actuation. To overcome the low thrust force of such driving scheme, unique magnetic circuits are used to enhance the thrust force and torque of the proposed actuator. Closed-form analytical solutions for modeling the magnetic field within the coil operating regions of these unique magnetic circuits are presented together with the complete thermal analyses. A prototype was developed and it delivers 10 mm stroke and 90 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$^{\circ }$</tex-math></inline-formula> angular displacement. Using commercially available drivers, it achieved a high throughput of 8000 units/h with 20  <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\mu$</tex-math></inline-formula> m, and 0.66 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{\circ }$</tex-math></inline-formula> tracking accuracy.