Method and apparatus for visual inspection of the internal structure of apparatus through internal passages

Abstract From the Canadian patent

The internal structure of an apparatus with internal passages such as a steam turbine is inspected without dismantling by inserting a compact robotic carriage device into a steam pipe and remotely controlling the carriage to carry a video probe to a restricted passage such as a nozzle block and to extend the probe relative to the carriage to inspect features within the restricted passage such as turbine blades. Separate motor drives for each side of the carriage include drive wheels of slightly greater diameter than a timing belt which serves as a tractor tread to drive the carriage over obstacles not bridged by the wheels. A large permanent magnet between the wheels is retained within the …