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Bearings sealed or not sealed? 1

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nisqually

Mechanical
Nov 26, 2002
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Hi. If I see zerk fittings on a motor then is it safe to assume that the bearings ARE sealed (ungreasable)? My millwrights have told me that motor manufacturers DO put zerk fittings on motors that have sealed bearings. Is this true? If so WHY would manufacturers put zerk fittings on motors with sealed bearings? WHY I ask you?
 
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Old frustrating issue.

We have picked on motor manufacturers for years, they all say the same thing, it would cost too much to discern which motor cases get zerks, and which do not.

Many motors have been ruined by this because maintenance technicians often grease every zerk the come upon. Putting grease into a zerk on a sealed bearing fills the back of the motor with grease, and can ruin the bearing by pushing the seal into the balls.

In the end I suppose this problem serves to separate the people that "know", and the people that do not "know". Surprise !!!

Richard Neff
Richard Neff
Irrigation Craft
 
BUT do you know whether they are sealed or not?

Some bearings are sealed on the outside and have the inner seal removed for relubrication purposes.

The safest thing to do is to get the parts list of the pump in question and check the part number of the bearings that are in there. Then you can check the bearing number with the bearing manufacturer to verify if it has inner seals or not.

There may also be an inner and outer spacer separating the bearings.

Good Luck!
 
I talked to Jim at Baldor. He told me his company does not put grease fittings on motors with sealed bearings. He said his motor bearings need 1 or 2 thimballs of grease per YEAR! He said the grease must be Polyrex EM.
 
I need more information nisqually.
I would like to talk to Baldor and learn something. Do you have a phone number?

My first question is how a sealed bearing needs 1-2 thimballs a year? I am not doubting, but how is that done and how does it work out on a sealed bearing?

We use Baldors frequently, good motors and the only US motor manufacturer we know of that still has good quality.

All the Baldors we use supposedly have sealed bearings. They range from 2-25 hp, we use them on our jockey pumps. And yet they all have zerk fittings.

I am obviously missing something. Richard Neff
Irrigation Craft
 
Sorry I wasn't clearer on my last post. He said if his motor had zerk fittings the bearings inside were NOT sealed bearings. And they needed a thimball of grease per year unless they were running 24/7 then they needed two thimball per year. That was my understanding. I am new at this whole bearing greasing thing, my background is piping systems and fluid flow. I reached Jim him at corporate headquarters (479) 646-4711. I clicked on "Contact Us" at to get the number. They will try to refer you to a local dealer but ask for Jim at corporate headquarters.
 
One other comment along the lines of Massey's comment.

Some people confuse sealed and shielded bearings.

Some people considered double-shielded bearings to be regreasable. Another controversy.
 
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