Failure of ISO PumpEnd ( Diesel Driven )

[IOC-AUS]

Hello All,
We have seen a couple of Broken Pump Shafts ( Stainless Steel ) on Diesel Driven ISO PumpEnds.
These are coupled via a 'Close Coupling' arrangement ( ie. Direct Pre-Load Bearing Adaptor with Muff Coupling between Pump & Engine ).
I attach a couple of Photos to help show the Failures.
Was hoping that the images might help to explain the potential Root Cause.
There have been 2x Impeller Nuts come loose on these PumpSets - another 3x have Snapped Shafts.
This is over a period of 3 years on only some units BUT comments and any tech advice much appreciated. Regards

 

[LittleInch]

Only one photo attached.

Looks like its rubbing on something to me and the shaft thickness reduced over time before it ran out of metal, but not much we can do with ONE photo, no drawings or any idea of the actual arrangement....

Were the pumps and motors aligned and checked on a regular basis?

But is that just the impellor? how does the shaft fit on?

Give us a bit more to go on than ONE photo please.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[Artisi]

Only see I photo.

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)

 

[IOC-AUS]

Trying to add a few more images

 

[IOC-AUS]

Another image

 

[IOC-AUS]

Last photo

 

[LittleInch]

How about a sectional drawing of the pump or a picture of what it should look like.

I have no comprehension of what is actually broken here.

I thought we were talking about a drive shaft?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[Artisi]

LI, you are looking at the pump inlet /impeller eye and it looks like the shaft extension / impeller locking nut is missing - how and why is a mystery.
Maybe someone left a crowbar in the suction pipe and its been banging into the locking nut and has beaten it to death.

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)

 

[TugboatEng]

The impeller has been removed from the pump. That's why you don't see the retaining nut. This pump has experienced a bearing or shaft failure which caused rubbing.

 

[Artisi]

Tug, your correct, my initial look, on my phone, it looked like the shaft was flush with the end of the impeller - after enlarging I see it's not shaft mounted
Time for new glasses.
but the photo doesn't tells us much anyway.

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)