Here at Grantham Electrical we have fully trained motor engineers who offer a full service package - from assisting in the removal of your motor, rewinding and repair, delivery back to site to and then assisting in the re-installation. We will even come and change bearings on site! We offer a full package from start to finish, below is an example of our work.
Mark and Dan replaced both bearings in a 250KW 4Pole Motor on one of our customer’s sites. On arrival, they were escorted up to the motor where they filled out a full risk assessment and agreed the job was good to go ahead.
The customer had already disconnected the motor and moved it away so our engineers had plenty of space to work. They started with the Non Drive End of the motor:
Once they had removed the fan and the end casing the motor then looked like this:
They then cleaned up the motor shaft to ensure there was no damage that was going to be affected by the bearing moving over it. They put our 3 legged bearing puller around the bearing and gradually stared applying pressure until the bearing moved freely and slipped off of the shaft.
As you can see above the shaft is clean ready for the new bearing to be put into place. To do this we use a bearing heater which is pictured below in action:
This slowly heats up the bearing which in turn expands the metal making the fitting of the bearing a much easier task, once the bearing is on the shaft it cools down and fits snugly into position. The bearing is then greased up and its ready for the end casing to be put back on, including the fan and the fan cowl.
Once the Non Drive end was finished our engineers moved swiftly on to the Drive End which had a Roller bearing on, making it a slightly harder task. For a start they loosened the bolts holding on the end casing and removing. They then put a bolt in the shaft which stopped our puller from damaging the thread used for the pulley which is used with this particular motor, after doing this they removed the roller bearing outer which just left the inner attached to the shaft.
To remove the inner race of the bearing they used heat and pullers, for a start they put tension on the puller then began to heat the bearing inner race which gradually expanded due to the heat meaning that when it was at the correct temperature the tension caused the ring to pull away with no harm to the shaft or motor. Once the shaft had been cleaned down and the new bearing heated up, fitted and fully greased up, the end casing was ready to be put back on after having a clean out of all the old grease.
Once this had been fitted again our engineers gave the site engineers a call and got it all up and running again to check everything over. As you can see Mark was very pleased with the job!