APPARATUS FOR REMOTE EDDY CURRENT AND ULTRASONIC INSPECTION OF TURBINE GENERATOR ROTOR RETAINING RINGS

摘要

The apparatus for inspecting large cylinders such as generator retaining rings, has sensors for simultaneously detecting flaws in inner and outer surfaces of the cylinder and in the body of the cylinder. The sensors are mounted on a scanner 22 which moves around the circumference of the cylinder and on which the sensors can move axially of the cylinder. The sensor outputs and sensor location signals are transmitted to a remote location 13, 16 and the apparatus is remotely controlled by computer 19. The sensors are eddy current and ultrasonic. The scanner has drive sprockets which engage chains placed round the cylinder and carries a platform which moves axially and on which the sensors are mounted. Position encoders act to accurately locate the sensors on the retaining ring. The retaining ring can be inspected while the rotor remains in place in the generator stator, or with the rotor removed.