Ball bearing noise

[Shrek]

Was wondering how ball bearings age

My boiler pump started making noises yesterday, and I was about to swap it out for a spare, but today the noise is gone. Was wondering if this was typical of how ball bearings wear?

I ask here as some computer fans are based on ball bearings.

 

[Norton]

Depends on the design of the bearing- they are typically sealed and over time the grease or the seal can dry out and dirt/moisture can enter the bearing. Dirt can wear out the bearings and the dried grease can cause them to overheat

 

[freeagent]

The lube is probably drying out, can you repack them with grease or are they sealed units?

 

[DrCR]

How old are the bearings?
Even if they are sealed, you could try getting a bit of mineral oil in there (low viscosity should let some weep in) to see if that improves things.

 

[Shrek]

Ah, but why did it go dead silent; that is the mysterious part.

 

[freeagent]

The ball rotated and is lubed again, if a ball stuck you will see its mark, and there may be a flat spot. Instead of mineral oil I would use sewing machine oil if you can find some, its lighter and will attract less dirt. But being 2023 I'm sure there is something readily available.

 

[Norton]

Ah, but why did it go dead silent; that is the mysterious part.

The pump impeller may have been rubbing against the pump casing due to play in the bearing and gone quiet when the impeller wore off some material or bearing shifted a bit.

Won't get better, will just start wearing out/breaking other parts of your pump. If the bearing gets too hot it will damage the shaft also. Best to get it apart and change it before it gets more expensive to repair or it becomes unrepairable

 

[Bill_Bright]

Was wondering how ball bearings age

Like anything that rubs against something else; friction.

No ball bearing is perfectly round or smooth. Same with the bearing channels they roll in.

No lubricant is 100% effective at totally eliminating friction - especially "forever".

And to nitpick a bit, no doubt it did not go "dead" silent. Aren't your ears almost as ancient as mine? And human too?

I suspect freeagent is right and the ball, NOT being perfectly round, finally bounced around and eventually rolled into a clump of lubricant that had settled out of the main path. It temporarily re-lubricated itself. But make no mistake. This is temporary. Damage was done and cannot be undone.

 

[freeagent]

If you have a spare set like I think you said you did, I would just go ahead and replace them.

 

[HTC]

Was wondering how ball bearings age

My boiler pump started making noises yesterday, and I was about to swap it out for a spare, but today the noise is gone. Was wondering if this was typical of how ball bearings wear?

I ask here as some computer fans are based on ball bearings.

Bearings are supposed to be 100% tested in specialized machines for low, med and high frequency noise @ some stage in the assembly section before being packaged for whatever client they are to be sold to: if the bearing is offside a certain range in ANY of the 3 types of frequencies, it's scrapped @ the factory, SUPPOSEDLY.

If the bearing is sealed on both sides, opening it up WILL ruin it, but i've seen bearings with only one shield (the metal disk that seals the bearing), with no shields, and even without cages (the thing that fixes the spheres in the ball bearing to have the same distance between each other): in those without one or both shields you can try and add a bit of lubricant grease ... but it may either mask the problem for a while or not work @ all.

Can you try and describe the type of noise?

It's been over 10 years since i last worked in the assembly section of the factory: i manufacture the rings for the bearings now. I used mainly to either insert the spheres in to the rings or place the cages in the bearings, back when i worked in that section.

 

[Shrek]

Noise: intermittent and a bit like the creaking of an office chair; now gone.

I was wondering about cavitation at the impeller, or even Teflon tape that may have come loose internally.

 

[Norton]

Noise: intermittent and a bit like the creaking of an office chair; now gone.

I was wondering about cavitation at the impeller

You could write a book, and they have, about all of the things that go bump in a pump (lol).... won't really know unless you pull it apart.

Since it's a boiler pump there will be scale buildup in the unit and it's possible you heard a piece of it come off the impeller and bounce around inside it.

Cavitation? Maybe, a change in flow or pressure can cause cavitation where it normally wouldn't occur

 

[Shrek]

It is a closed circuit so probably no scale build-up, but that does not mean you are not right.

 

[HTC]

Noise: intermittent and a bit like the creaking of an office chair; now gone.

That "sounds" like a bit of impurity got in to the bearing and, when it's not @ the edge of the rings where the spheres don't usually reach, you don't hear it but, when it gets caught up by a sphere again, you'll hear it.

 

[freeagent]

My high efficiency furnace is about 8 or 10 feet behind me in my unfinished basement. So its blower spools up pretty high. Last year and the year before she was chirping, this year no chirping yet.. but I expect a failure in the next few years if I don't do something about it.

Also, that is how I can handle loud fans.. usually my furnace drowns them out.. except for my iPPC when they are up and running. They are damn loud.

 

[Shrek]

I noticed that the pump is installed to push water down which is perhaps not a great direction as it is hard to clear air pockets that way and that might explain the intermittent noise as the bubble fights its way up and down.

 

[stinger608]

@Shrek , if this is a boiler circulation pump, make absolute sure it's actually running. It may have froze up and that's why it's "silent."

 

[Shrek]

I should not have said silent (my bad); it hums, and the heating works fine.

I took the advice here and replaced it with the spare which seems to be of higher quality.

 

[Shrek]

Turns out I was TOTALLY wrong and the motor uses water as the bearing lubricant, and should not be run dry.

 

[Bill_Bright]

I find that hard to believe - or at least I cannot picture it in my head.

I can picture the impeller shaft being lubed by the lubricants in the coolant. But the motor bearings are not (or shouldn't be) in the flow of water. So (in my mind) the motor bearings themselves still need some other type of lubricant. Or is the image in my head totally wrong?

 

[eidairaman1]

I find that hard to believe - or at least I cannot picture it in my head.

I can picture the impeller shaft being lubed by the lubricants in the coolant. But the motor bearings are not (or shouldn't be) in the flow of water. So (in my mind) the motor bearings themselves still need some other type of lubricant. Or is the image in my head totally wrong?

Thats how AC compressors work

 

[Shrek]

I find that hard to believe - or at least I cannot picture it in my head.

I can picture the impeller shaft being lubed by the lubricants in the coolant. But the motor bearings are not (or shouldn't be) in the flow of water. So (in my mind) the motor bearings themselves still need some other type of lubricant. Or is the image in my head totally wrong?

Ceramic bearing

LUPTL006new

"When UPS 15-42 and UPS 26 pumps are first started, the shaft
may rotate slowly until water has fully penetrated the
bearings."

"Never operate the pump dry."


I, like you, am rather taken aback.

 

[HTC]

Ceramic bearing

LUPTL006new

"When UPS 15-42 and UPS 26 pumps are first started, the shaft
may rotate slowly until water has fully penetrated the
bearings."

I've seen bearings with ceramic spheres, but NOT the whole bearing made of it.

Some types of bearings where i work use ceramic spheres: they are more expensive than their metal spheres bearings' "cousins".

 

[Shrek]

I had always wondered how they stop the pump leaking; now I know, the rotor can be in its own sealed case (that the stators magnetic field penetrates) and the bearings are fine 'leaking' water. This may also explain the rather low efficiency: 89W for 1/25 HP (= 30W)

 

[Norton]

Interesting design (below is not necessarily your pump but same style).

Understanding Canned Motor Pumps - Efficient Plant (efficientplantmag.com)