Ultrasonic apparatus for examination of cylindrical objects - rotates on hydrostatic bearing to prevent damage on starting

摘要

Ultrasonic inspection of tubes is carried out by rotating a sleeve assembly (13) around the outside of the pipe (37). There are four ultrasonic crystals (12) connected via slip-rings (24) and brushes (29) to the external circuitry. The sleeve rotates on a hydrostatic bearing. Water is lead to four flats (14) on the surface of an inner fixed sleeve (3) forming pressure pads to locate the sleeve. Water also flows to two annular channels to lubricate the locating collar (17) and into the space (10) between the crystals and the sample to couple the ultrasonic waves. A gear wheel (23) is driven by an external source at a rate high enough to fill the whole of the space (10) by centrifugal force.