Which Scanning System Is Suitable For Welding Copper Hairpins In Electric Motors?

The efficiency of the EV drive motor is the same as the fuel efficiency of the internal combustion engine and is the most important indicator directly related to performance. Therefore, EV makers are trying to increase the efficiency of the motor by reducing copper loss, which is the biggest loss of the motor. Among them, the most efficient method is to increase the load factor of the stator winding. For this reason, the hairpin winding method is rapidly applied to the industry.

The electrical slot filling factor of hairpin stators is around 73% due to the rectangular cross-section area of the hairpins and the smaller number of windings. This is significantly higher than with conventional methods, which achieve approx. 50%.
In the hairpin technique, a compressed air gun shoots preformed rectangles of copper wire (similar to hairpins) into slots on the edge of the motor. For each stator, between 160 and 220 hairpins have to be processed within no more than 60 to 120 seconds. After this, the wires are intertwined and welded. Extreme precision is required to preserve the electrical conductivity of the hairpins.
Laser scanners are often used prior to this processing step. For example, hairpins from particularly electrically and thermally conductive copper wire is often stripped from the coating layer and cleaned by laser beam. This produces a pure copper compound without any interfering influences from foreign particles, which can easily withstand voltages of 800 V. However, copper as a material, despite its many benefits for electromobility, also presents some drawbacks.

With its high-quality, powerful optical elements and our customized welding Software, The CARMANHAAS hairpin welding system is available for the 6kW Multimode laser and 8kW Ring laser, working Area could be 180*180mm. Easily processes tasks requiring monitoring sensor can also be provided on request. Welding immediately after taking pictures, no servo motion mechanism, low production cycle.

Galvo Laser Welding-2

•   Equipped with 6 million pixel high-resolution industrial camera, coaxial installation, can eliminate errors caused by tilted installation, the accuracy can reach 0.02mm;
•   Can be matched with different brands, different resolution cameras, different galvanometer systems and different light sources, with a high degree of flexibility;
•   The software directly calls the laser control program API, reducing the time to communicate with the laser and improving system efficiency;
•   Pin clamping gap and angle deviation can be monitored, and the corresponding welding procedure can be automatically called for the deviation pin;
•   The pins with excessive deviation can be skipped, and repair welding can be carried out after the final adjustment.


CARMANHAAS Advantages of hairpin stator welding
1. For the hairpin stator laser welding industry, Carman Haas can provide  one-stop solution;
2. Self-developed welding control system can provide different models of lasers on the market to facilitate customers' subsequent upgrades and transformations;
3. For the stator laser welding industry, we have established a dedicated R&D team with rich experience in mass production.

Post time: Feb-24-2022