Development of Ultrasonic Flaw Detection Instruments for Hollow Shafts of EMUs

The ultrasonic flaw detection instrument for hollow axles of EMUs mainly consists of an ultrasonic testing system, a data processing and display subsystem, a positioning subsystem, an electrical control system and an overall mechanical framework, etc. This achievement is the first of its kind in China. Compared with similar foreign equipment, it has significant advantages in compatibility, flaw detection scanning time, flaw detection accuracy and application scope, and is at the international level.

First, the unique sealed rotating oil cavity technology stores the coupling oil in a closed space, ensuring excellent coupling effect and effectively protecting the probe, thus effectively solving the problem of poor coupling in the original probe rod system.

Second, a coupling oil recovery system was innovatively designed in the rotating oil chamber of the probe rod, enabling the probe rod to have a dual oil circuit system for oil supply and suction. The coupling pressure is stable, ensuring that the coupled oil always remains in the rotating sealed oil chamber, while the other parts of the probe rod are separated from the oil. The fault that the entire probe rod was immersed in oil, causing some electronic components to malfunction due to oil leakage, has been resolved.

Thirdly, an innovative design of the probe feed motion guide pulley was carried out to ensure the concentricity of the probe and the inner hole of the hollow shaft, making the flaw detection process run smoothly and guaranteeing the stability of the coupling of the probe during its circumferential movement.

Fourth, more efficiently complete the scanning work for defects in hollow axles. The rotating part at the front end of the probe adopts a brand-new probe layout technology, featuring excellent balance and accurate rotation centering. The unique sealed rotating oil cavity technology enables the coupling oil to be stored in a closed space, ensuring an excellent coupling effect and effectively protecting the probe. It also solves the coupling problem commonly found in the probe systems of other foreign manufacturers. The probe adopts coupled oil recovery technology and is equipped with dual systems for oil supply and suction. The coupling pressure is constant and the sealing performance is good, which can ensure that no oil enters the probe.