Tension control of a winding machine for rectangular coils

This paper introduces the design and testing of tension control prototype systems to minimise these tension variations, which includes a fluidic muscle powered take up arm, a fluidic muscle wire accumulator and felt pad. First the model and their limitations for existing tensioning systems are identified. Then, they are theoretically analysed in simulations. The simulation results show that the acceleration and deceleration of the wire due to the changing wire path length causes a cyclic tension fluctuation. An online tension sensor verified the predictions of the model. The key for a successful design is to remove tension variations. We propose to add a wire flattening machine which includes an accumulator and tensioning device, and replace the conventional pneumatic cylinder powering the accumulator with a fluidic muscle. The simulation shows that the new prototype system almost doubles the winding speed with a tolerable tension fluctuation.