Robotic Crawler for Inspecting Generators with Very Narrow Air Gaps

Abstract

The non-destructive inspection of generator stators is a repetitive and cost-intensive task.For some types with very small entrance gaps (around 9mm height), it was even necessary to always remove the rotor.This paper describes the design and prototype implementation of a new robotic crawler which is only 8mm high and thus can inspect all types of generators with the rotor installed.Different solutions of how to realize torque transmission and attraction forces at such a small size are discussed, as well as the design of magnetic guiding wheels with a mechanism to fold them when passing the narrow entrance gap.The paper concludes with some test results -both in an artificial test environment and in real generators -and provides an outlook on future improvements of the prototype.