Analysis on the electromagnetic force for elliptical and circular movement of orbital friction vibration head

The applications of Orbital Friction Vibration Head (OFVH) have fell into a wide range of industries due to its many merits. The quality of welding products directly depends upon the operational performance of OFVH as a core component of Orbital Friction Welding (OFW). By taking advantage of the special electromagnetic structure, OFVH can produce a contactless, radial, synchronous and rotating force with adjustable amplitude and phase upon the still mover which will then vibrate according to the predetermined orbital. If the motion trajectory generated by the actuator is close to circular, it can be deemed that it ensures better contact over the interfaces of the welded workpieces, more uniform welding heat and solid welding joint. This paper analyzes the operational principle and structure of OFVH and conducts a mathematical analysis for a core issue about how to make the motion component of the OFVH generate specific moving trajectories. The expressions of the electromagnetic forces needed are employed to establish the simulation model, and then the analysis is validated.