Mechanical Repairs
It is not uncommon for what our customer thought was a routine and simple motor repair to turn into something more serious.
We receive a phone call and our customer indicates that the motor went "off line" due to an overload. They attempted to reset the control's overload relay but it happened again in a short amount of time. So we get the motor in the shop and check it out. We find the rotor is "hard to turn". Certainly the bearings are an issue. So we disassemble the motor and remove the rotating assembly. The mechanic finds that the rotor has been rubbing on the side of the laminations. Maybe we're fortunate enough and the winding is still good. But, we check the rotor in the lathe and found the shaft is bent! How unfortunate. Maybe we can straighten the shaft, depending on where it's bent and how severe. Or maybe we need to make a new shaft. In any case, this is NOT going to be a quick, routine, or simple motor repair.
But not to despair, A.R.&E. can do any of the above mentioned "fixes". We have the expertise to press out the old shaft, duplicate it's dimensions on a CAD drawing, and make a new shaft in the machine shop. Once the new shaft is made, it can be pressed back into the rotor and the complete assembly is then "dynamically balanced" to assure extended bearing life when the motor is put back in service.
Other instances of mechanical failures and repairs include cutting a NEW keyway in a shaft when the original one had been "damaged" by a defective coupling bore. And we can make that keyway an "open" keyway or an "enclosed" keyway, whichever you desire, or whatever fits the application properly. There are those applications and instances where an "enclosed" keyway is REQUIRED. We can take care of that for you. And since the "mass" of the metal shaft has changed, this unit will be "dynamically balanced", too.
A more common repair for our technicians is the rebuilding of the bearing housing in the end bell of a motor. If a ball bearing fails, in many cases, it begins to turn inside the bearing bracket and wears the housing to an "oblong" shape or worse. A.R.&E. will re-bore the housing, press in a new steel insert and "re-machine" the bore to the proper size for the bearing being used. The other bearing problem is caused when the bearing gets so hot (when it fails) that it seizes to the shaft of the rotor. If this happens, it may be necessary to "burn off" the bearing (and repair the shaft) or it may be so destroyed that the shaft needs to be cut off and either a complete NEW shaft made OR... we may be able to manufacture a "stub" shaft to attach to the end of the original. That's a little more advanced based on the welding and re-machining that needs to be done, but it can happen. And it can be done in our Hagerstown Maryland shop.
Sleeve bearing repair requires a specialized talent and skill in our industry. Getting the clearances just right takes the knowledge and experience of our most senior mechanics and technicians. Sleeve bearings are "usually" made of brass or bronze, or may be a cast iron housing with "Babbitt" material poured and machined as the actual bore and bearing surface. "Babbitt" is a soft metal alloy that was invented and formulated around 1840. The alloy was a "Tin" based metal (alloyed with Lead, Antimony, Copper, and Arsenic) and as such, with tin being softer, it would "melt" under the frictional heat and actually become a type of lubricant. As the Tin melted, it left "indents" in the base metal and these indents acted as "reservoirs" for the lubricating oil. Babbitt is still used today, mostly in larger equipment and things like high speed turbines. It works well because there are no moving parts, as there is with a ball or roller bearing and high speed is not an issue. However, the design and shape of the "oil ring" in a sleeve bearing is extremely important since it is a primary source for getting lubrication to the shaft and bearing.
So if you feel your situation has to do with a "mechanical" problem, don't be concerned. Give our shop superintendent a call and you'll be guided through the processes that would best suit your timeframe and application. No two failures are the same and different applications require different solutions. We're here to help...
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