Fully automated rotor inspection apparatus with high flexibility for permanent magnet synchronous motors using an improved hall sensor line array

Abstract

As a result of the market expansion of permanent magnet synchronous motors due to the increasing demand for high-performance drives for a wide range of applications such as traction drives for electric mobility, positioning drives for machine tools as well as high-precision drives for special-purpose machines and the quality demands involved, in-line capable measurement technology is needed. Thus in the area of electric drives manufacturing the rejection rate is required to be reduced by early fault detection. This can be achieved by measuring the rotor excitation field created by permanent magnets prior to the assembly of rotor and stator. In this Paper an apparatus for fully automated inspection of both internal and external rotors within a wide range of dimensions is presented. This is done with the aid of a one dimensional Hall-Sensor line array, which is manufactured with high accuracy and the use of an open source CNC system. The presented device is capable for in-line operation at the end of the rotor assembly process chain to detect possible magnetization and assembly faults prior to the final assembly of the electric drive by visualization of the rotor excitation field.