New Methods for Measuring Critical Dimensions of EV Motor Stator Assemblies

Abstract

Demand for electric vehicles, and buyers' appetite for longer range, put increasingly stringent requirements on the precision manufacture of electric motors – and hairpin shape, alignment and mounting in the stator body have become critical to motor efficiency. As volumes grow, the measurement cycle has to shorten at the same time. Lars Virgin and David Wick describe two approaches to measuring the critical hairpin dimensions in an EV stator assembly: a blue structured-light scanner, and a traditional coordinate measuring machine now equipped with a rotary table and optical sensors, giving four-axis laser line scanning, quick 3D point cloud acquisition and camera inspection of the slot liners. The challenges of each are set out, and the results compared and contrasted.