Challenges in the manufacturing of hairpin windings and application opportunities of infrared lasers for the contacting process

Accelerated by electric mobility and new requirements regarding quantities, quality and innovative motor designs, production technologies for windings of electrical drives gain in importance. Especially the demand for increasing slot fill ratios and a product design allowing manufacturers of electric drives to produce big quantities in a good quality impels innovations in the design of windings. The hairpin winding is a result of this development combining high slot fill ratios with new potentials for an economical production of the winding for electric drives. This is achieved by a new method for the production of the winding: The winding is assembled by mounting preformed elements of insulated copper wire to the stator simplifying the elaborate winding process on the one hand. On the other hand it becomes necessary to join these elements mechanically and electrically to manufacture the winding. Due to this, contacting technologies gain in importance regarding the production of hairpin windings. The new challenge consists of the high number of contact points that have to be produced in a small amount of space. On account of its process stability, high process velocities and the possibility of realizing a remote joining process, the laser welding shows big potentials for the realization of a contacting process for hairpin windings that is capable of series production. This paper describes challenges and possibilities for the application of infrared lasers in the field of hairpin winding production.