Quality Assurance for Stators
Insights into Stators
The stator is responsible for the latest generation e-motor’s performance. This component has the biggest potential to improve the performance, power and efficiency of an e-motor. New raw materials and innovative manufacturing technologies make quality assurance across all production steps necessary to guarantee the safety, reliability and performance of the e-motor.
During the stator assembly, the insulation paper and hairpins are inserted into the slots of the sheet stack and welded together. The power supply connection points are also welded. A number of characteristics require inspection, such as the positions of the laser-welded ends, to avoid short circuits in the stator. Flexible tactile and optical technologies are necessary to get accurate inspection results on positions and dimensions due to the very flexible copper hairpins – a ZEISS multisensor coordinate measuring machine.
Weld Seam Inspection
The hairpin ends must be laserwelded to allow current to flow through the stator, generating the electric field. In the weld process, remaining lacquer material on the stripped pins or bad welding parameters can cause porosity in the weld seams – and result in poor performance or the total breakdown of the e-motor. ZEISS computer tomography (CT) technology can detect, locate, classify and rate the internal pores of the weld, finding defective stators in a non-destructive quality assurance process.
Assembly Volume Inspection
The outer boundary of the stator is crucial for mating the stator in the e-motor housing. The connection flange and shaft position require inspection in relation with the transmission. It is essential that this data be collected quickly and thoroughly. These requirements can be achieved by using ZEISS laser line triangulation technology. This handheld, flexible option saves programming time to have measuring results available quickly – or an automated ZEISS coordinate measuring machine is ideal for higher quantities.
The components of electric motors must be perfectly matched to each other to meet the requirements for safety, reliability and performance. Using optical 3D measurement technology, hairpins and stators can be fully digitized and inspected automatically in a very short time before assembly. A complete geometric digital twin is created in the software from area-distributed 3D coordinates, which can be used to detect deviations and defects quickly and reproducibly in component geometries compared to the CAD model.