Remote controlled apparatus for eddy current and ultrasonic checking of retaining rings of turbogenerators

摘要

The apparatus comprises a scanning appliance 22 which provides the simultaneous actuation of sensors for checking by eddy currents and by ultrasonics in order to carry out checking of the retaining ring 25; the scanning appliance 22 is controlled by a system 19 provided with a computer and it includes position coders for precisely positioning the sensors on the retaining ring; the scanning appliance 22 can turn around the whole circumference of the retaining ring, and it is also movable linearly parallel to the axis of the ring in order to carry out a check in a single pass; the apparatus includes special elements for data acquisition and for display of the information originating from the sensors; the retaining ring can be checked although the rotor remains in place in the stator of the generator, or also after removal of the rotor.