Pump Tire Coupling on Fire

There could be multiple failures leading to this problem....I would check the shafts for voltage and temperature during operation looking for bad bearing or slip-ring or insulation failure, and also consider a more robust tyre coupling design...

https://blog.shafttech.com/article/atex-couplings-in-the-oil-and-gas-market-esco-renold-fenner-and-rexnord-thomas/

It seems there must be a flammable substance, possibly degreaser or something, and a spark being created for ignition...

So you think it may be caused by misalignment that could have caused friction between the guard and the tyre?

No...Improperly grounded shaft would be my guess...

Would you mind explaining to me how it occurs please?

"An improperly grounded shaft can cause voltage to build up and arc across the motor bearings, damaging them. This can lead to abnormal wear and tear on the bearings, which may include pitting, scarring, discoloration, and fluting."

Any flammable substance can be ignited by a spark with oxygen present...

The shaft can get voltage from bad slip rings, static buildup, insulation failure, VFD...

https://www.helwigcarbon.com/factors-that-influence-shaft-grounding-performance/

Not saying this is the cause, but certainly should be checked...

I'm sorry, but none of your photos have enough detail for me to know what I'm looking at.

Also, we may have a semantics problem. What exactly is a "Pump tire coupling"? My current mental image is a flexible coupling between a motor shaft and a pump shaft that uses pieces of vehicle tire to produce the flexibility.

I believe you have the right idea. This is my understanding as well:

https://m.youtube.com/watch?v=q90ihOv5nvY&pp=ygUVcnViYmVyIHRpcmUgY291cGxpbmcg

Image #1, the coupling appears to be burning, rather than burnt.

Thanks. Now I can go back and take a second look. One characteristic of this kind of coupling is that the Outside Diameter changes with the spacing between the two flanges. if the motor and the pump are mounted too close together, or the flanges are mounted too close to each other, then the OD will be larger than intended, and could possibly be large enough to rub on the guard.

If the clamping mechanism that holds the flange on either shaft loosens, then the "centrifugal force" of the spinning coupling will tend to make it move outward, bringing the two flanges closer together, possibly with the same result.

In photo #3, it appears that the guard is either wire mesh or expanded metal. In either case, something falling on/impacting the guard could have bent it inward enough to cause contact with the tire.

I suspect this is the result of a lack of preventive maintenance.

Stuck brake on wheel,bent wheel,bad bearing, lack of lubrication..This looks like a seal to me,but that may just be a language barrier.

A bad bearing or stuck brake could overheat the seal,carbonize the grease,resulting in more friction,more heat until finally,a fire.Look at the bearings closely.They should have a Mirror finish,not just bright,a mirror.If they are okay,examine the brakes servo for stuck linkage or leaky diaphragm.

(I am presuming this is part of a semi tractor wheel or trailer wheel,due to insufficient information in your post.More info always helps.Where is the video you mentioned?)

If this is really a coupling,the shafts look misaligned,causing flex in the coupling,and heat,If not misaligned,then excessive load could also cause excessive flexing on the coupling and create enough heat to combust.It also appears that the coupling has been rubbing on something,perhaps a guard?Look for marks on the guard or surrounding material for signs of contact with the coupling.

Bah! Image of a bad seal won’t stick.

An external seal,as in a CV joint boot.Not enough info to really tell what we are looking at.

No, this sort of bad seal:

https://media.makeameme.org/created/me-when-i-1f94b1c404.jpg

Our OP Maheva is a young ME, works at a mining operation in Madagascar.

Thank you for answering, it is an elastomeric coupling installed on a centrifugal pump. it is designed to support misalignment from vibration

The video couldn't be sent. So I sent a screenshot instead

In your image #2, are we seeing abrasion? From the expanded metal on the guard? If yes, I would speculate this, combined with the causational misalignment, is a major contributor to failure.

This is why I mentioned it on my comment above (comment #3).

Yes, it is abrasion, I think due to friction between the guard and the tire that is made of rubber.

But the cause of the friction is still unknown until now

Installation appears to be aged in place, leading me to suspect mounting to floor of A) Motor - B) Pump - C) Coupling guard has loosened or broken.

OR...

... as previously suggested, horribly worn bearings. Were this the case, I doubt the rubber coupler would be the first unscheduled thermal event to be of concern.

Is this equipment stationary, or mounted on a pallet or skid?

If skid mounted (as maybe a dewatering pump), is the skid itself perhaps no longer in the original condition?

Hi, this is not a Tyre, it is a Rubber Coupling being used to compensate for Vibration between the Motor and the Pump.
Without knowing how old the "Rubber " is and the environent being run in ( chemicals etc. ) it could simply be the material breaking down and catching on the metal housing and eventually burning.
Unfortunately the fotos supplied are not very clear.

Usually alignment fatigue and/or frequent/high torque starts cause heat buildup and failure. Make sure alignment and starting torque is withing spec.

Abrasion is evident in image #2.

For all we know, a large rock or perhaps a tool has somehow found its way into the enclosure guarding the coupler, and removal of the offending object will resolve the issue.

As George Tsoukalos tells us, if something happens and the cause is not self evident, then aliens probably did it.