Design Procedure of an Eddy Current Damper Type Reaction Force Compensation (RFC) Mechanism for a Linear Motor Motion Stage

Base vibration of a linear motor motion stage has been reduced with passive RFC mechanism based on movable magnet track and springs. This paper presents design procedure of an eddy-current damper (ECD) type RFC mechanism for a linear motor motion stage. The RFC mechanism with a movable magnet track and an ECD can overcome disadvantages of the spring based RFC mechanism such as resonance and difficulty of assembly due to spring. A lumped parameter model for the ECD type RFC mechanism is derived considering sinusoidal magnetic flux density and effective width of the ECD according to magnet track motion. Then, a design procedure for ECD type RFC mechanism is proposed to meet system requirements such as transmission ratio of reaction force and maximum magnet track motion. Design example illustrates the effectiveness of the proposed design procedure for ECD type RFC mechanism.