Mechanical Engineering Wiki / Hairpin technology
Hairpin technology
Hairpin technology is a winding technology that is used, among other things, in electric motors. The technology is named after the plug-in coils, whose angular U-shape is reminiscent of hairpins. Compared to conventional coil winding technology, hairpin technology offers decisive advantages that make it particularly attractive for use in traction motors in electric vehicles .
What is hairpin technology?
Hairpin technology has been on the rise for several years, particularly in the automotive industry. After all, it represents a time and cost-saving option for the production of high-performance electric motors . More specifically, winding technology is used in the stator of the traction motor. This typically contains coils made of electrical conductors (copper wire), which until recently had to be wound in a complex process. Depending on the thickness of the copper wire, this is a labor-intensive and time-consuming process. Thanks to hairpin technology, however, the copper electrical conductors can now be plugged in: Depending on the manufacturing technology, they are inserted into the stator using a compressed air gun, for example. The hairpins then only need to be twisted together and welded.
What are the advantages of hairpin technology?
Hairpin technology offers several advantages over conventional coil winding in the production of stators for electric motors: By accelerating the insertion of the plug-in coils into the stator, the production time of electric motors is reduced enormously, which in turn provides an additional plus on the cost side. In addition, more plug-in coils can be placed and connected in a smaller space. This increases the copper filling level in the stator, which generates a high continuous output.
What challenges does hairpin technology present?
Hairpin technology has proven to be advantageous in many respects for the production of stators for electric motors, but it also presents a number of challenges. The bending (twisting) and welding of the hairpins alone makes the production process complicated and requires innovative solutions. After all, a large number of welding points must be produced in first-class quality . In addition, the larger winding heads of hairpin technology can cause electrical losses.