Optimizing the Productivity of the Linear Winding of Rectangular Shaped Coils Using a Servo-based Wire Tensioning System

Linear winding is a well-known process for producing concentrated wound stators for electric drives. Single tooth windings are widely used in many types of industrial motors. Due to the high production volumes of these motors, an improvement in winding speed is beneficial for productivity and is the subject of this paper. Conventional winding equipment for single tooth coils use various passive electro-mechanical wire tensioning systems to adjust the tension in the wire, which is essential for a proper winding process and an orthocyclic winding result. Winding single tooth coils, which have a rectangular cross-section, results in variations in wire feed rate, requiring a more powerful and flexible wire tensioning system. Servo-based wire tensioning systems offer an advantage when winding rectangular-shaped coils by modeling the wire feed rate behavior based on the coils geometry and additional sensor data. However, since this system is actively controlled, greater variations in wire tension can be introduced if the calculated wire feed velocity does not exactly match the actual physical process. Therefore, an experimental method is used to determine the relevant parameters of the winding geometry and machine that influence the wire tension and the winding process, in order to derive parameters for the servo-based tensioning system to enable even higher winding speeds while maintaining coil quality. In addition, the feasibility and effect of deliberately varying the wire tension is investigated, which is not possible with passive wire tensioning systems.