Hospital Air Handling Unit Repair
With the motors still running and belted up, the shaft had been pulled to one side, which had worn through the outer bearing casting and then through the main bearing spider arm support arrangement. The impeller had also scored a hole in the fan casing, and it was obvious that this air handling unit repair was not going to be a quick fix!
The site team got to work immediately and fully dismantled the unit. They then brought the impeller, shaft and bearing support assembly back to Webb-Elec’s works. The engineering team then quickly manufactured a replacement drive shaft and sourced a complete set of replacement support bearings, drive pulleys and belts. The main bearing support arms were bespoke, so a repair solution was fabricated and welded in place to ensure the arms were as strong as they had previously been. All this was carefully set up and aligned to ensure that no twisting was introduced into the structure, as this could adversely affect the bearing and shaft alignment.
The impeller was then carefully cleaned and inspected for any damage that would affect its performance. Once cleared as fully serviceable, it was set up on a CEMB Hofmann balancing machine and dynamically balanced.
Webb-Elec’s team then returned to the site and began to rebuild the unit. They fixed a plate in place to repair the scored scroll casing and refitted the shaft and impeller assembly. The new bearings were fitted along with the repaired support arms, and the pulleys were set up and laser aligned. Finally, the belts were fitted, and the unit was fully run-tested.