Quality Assurance for Sheet Stacks
Sheet inspection and stack positioning
Ensuring stack quality sheet by sheet
Tight tolerances and pristine surfaces
Single 2D sheets provide the foundation for constructing sheet stacks in rotors and stators. Sheet stacks comprise numerous sheets, each punched or laser cut from electrical steel sheets and with a thickness of less than 1 mm. Key quality aspects include the cross-section slot geometry for the hairpins, the permanent magnet slots, and the inner and outer diameter of the sheet stack assembly. Since tolerances are in the micrometer range, the sheets must be flat and burr-free to ensure proper e-motor performance.
Key quality challenges for sheet stacks
Single sheet inspection
Production of single sheets
Since the geometry of the 2D sheet defines the dimensions of the final stator and permanent magnet slots, it is very important to measure these dimensions quickly and with high accuracy. The sheet thickness and associated flexibility lead to measurement challenges.
Geometrical inspection
Production of single sheets
ZEISS multisensor technology, such as 2D cameras and confocal light sensors, is used to measure the flatness of each individual sheet. Flatness and the absence of burrs are key factors for ensuring a sheet stack that is perfectly constructed and easy to assemble.