Bearing failures that could have been avoided. Let’s look at the issue from a maintenance perspective…
If you’ve ever hunched over an oily machine body towards the end of a three-shift week, you know: bearings are not toys. The little bugger makes big trouble. And then you ask, “What the heck is this thing broken again?”
Most of the time, it’s because it’s been put back in like it’s a rubber candy, not a precision machine part.
Let’s take a look at the bearing failures we see every day – and the ones that make even the most experienced maintenance man scratch his head.
1. Overheating – the classic end
No need for nuclear physics: if your bearing is getting hot, it’s either over-tight or not getting enough lubrication. A typical mistake is hammering the inner ring onto the shaft with a hammer, as if it were a pipe release. Then we wonder why the inner ring gets microcracks and the lubricant oozes out like good broth.
Prevention: mounting with a special tool e.g. Simatool and Simatherm, precise tightening with normal torque – no need to pull from biceps.
2. Contamination – the killer of the bearing
Reaching into grease with an oil stained finger is like putting a sterile needle back in the mud. Dust, rust, metal filings – they all get in and grind. And the mirror-smooth track of the bearing will look like you’ve put plaster on it.
Prevention: clean environment, gloves, and don’t spray the bearing with a compressor on the floor, or you’re done for.
3. Bad fit – either too loose or too tight
Many times a bearing dances on the shaft like it’s going to a disco. Other times it can only be removed with a flex, it’s clamped on. The end result is the same: premature death. One wears, the other cracks, but both are dead.
Prevention: micrometers are not spared. Fitting table, ISO standard, no abdominal thrust. It’s not drywall, it’s “it’ll be fine that way”.
4. Electrical damage – when the electricity hides the bearing failure
This is the fault that many people don’t see coming. An electric motor bearing can develop a micro-arc if the insulation or earthing is not in order. Then the roller burns out the raceway nicely and the bearing can go in the bin.
Prevention: insulated bearing or grounding carbon brush.
5. Improper installation – the hammer is not everything
It’s not uncommon in machine shops for the mechanic to take the inner ring and hammer it onto the outer ring. This is how the bearing becomes wrought iron.
Prevention: only apply pressure where it is needed. Inner ring = shaft, outer ring = housing. What’s in between is just the soul of the bearing, don’t hurt it.
6. Atypical killers – bearing failures that only the experienced eye can spot
- Vibration set-up: when the machine is stationary for a long time but vibrates (e.g. during transport), the rollers “bump” into the track. When it starts to move, it is already humming.
- Grease inversion: there have been machines where too much grease has been pressed in, and then when it heats up, the grease is squeezed out – and the bearing is left dry as a heated desert.
- Faulty retensioning: with a roller bearing, they preloaded it like a steering bearing and wondered how it would bounce.
The bearing does not tolerate sloppiness. Those who fit accurately, cleanly and professionally rarely change. But for those who think a hammer will do the job – there’s always a supply in the warehouse.
Simatherm and Simatool bearing installation tools and equipment have been developed precisely to make life easier for maintenance technicians and to make tedious tasks clean, precise and fast.
Get your new maintenance tools now with a 20% discount between 5 and 31 May 2025 while stocks last!
