A BRUSH customer experienced a significant short circuit failure with one of their 3rd party manufactured 2-pole turbo rotors. The loss of capacity was causing problems to the site and needed to be resolved quickly and effectively.
BRUSH found that the coils and the drive end retaining ring had experienced heavy short circuit damage.
The damaged rotor coils were carefully removed from the rotor so not to cause undue stresses and deformation to the coils. They were then thoroughly cleaned to remove dirt, debris and the old insulation. The drive end retaining ring had to be cleaned and dye penetrant inspected according the BRUSH Aftermarket quality management programme.
Due to the damage to the retaining ring a machining process was conducted and final grind performed to address the damage. An ultra sound inspection was then performed to pass the retaining ring as "fit for purpose"
After re-assembly with new blocking and insulation all elements and assembles were extensively tested according the BRUSH Aftermarket quality procedures.
The rotor was then balanced and an over speed test of 110% was performed which was witnessed by the client.