ZEISS eMobility Solutions

Quality Assurance for Sheet Stacks

Insights into Sheet Stacks

The sheet stack is built out of many single sheets, including crosssection slot geometry for the hairpins, permanent magnet slots and the outer- and inner diameter of the sheet stack assembly. Single 2D sheets provide the foundation for constructing sheet stacks for rotors and stators. The single sheets are either punched or laser cut from electrical steel sheets, and are less than 1mm thick. The final sheet stacks require a large quantity of individual sheets.

Single Sheet Inspection on ZEISS Multisensor CMM

Sheet inspection

The geometry of the 2D sheet defines the dimensions of the final stator and permanent magnet slots. This is why it is so important to measure these dimensions quickly and with high accuracy. An ideal solution is to utilize ZEISS multisensor technology, such as 2D cameras and confocal light sensors, to measure the flatness of each individual sheet. The flatness and the non-existence of burrs are key factors to ensure a sheet stack that is perfectly constructed and easy to assemble.

Assembly Quality

During the assembly of the sheet stack, the positioning of the single sheets for laser welding has a major impact on the geometry of the stator and rotor slots, which are mated with the hairpins and the magnets. After welding, it is important to inspect the dimensions and positions of the slots, as well as the height and diameters of the sheet stack. The contour features on the assembly are also important for the process of inserting the hairpins and magnets. ZEISS multisensor coordinate measuring machine can be combined with 2D cameras and whitelight confocal sensors to perform even more thorough inspections – for quality assurance you can rely on.

Tactile Sheet Stack Measurement on ZEISS Bridge-type Multisensor CMM
Contour Measurement with Confocal Whitelight Sensor on ZEISS Bridge-type CMM