High Bearing temperature

Ananth,

You say that the the clearance of 0.1 is as per specification. I think that this could be your problem. This is a C3 bearing which has a radial clearance once fitted on the sleeve of 0.2 min and 0.26 max. Fit the bearing to these tolerances and see if that helps.

Another possible cause of bearing overheating that can be easily rectified is too much grease. Make sure that this is not part of your problem. Rather have slightly too little (say one third of the bearing area) grease and then start up. You can then add grease once running at a stable bearing temperature. If you do not have grease relief holes make them if possible.

Let me check the clearance once again and will come back to you.

with regards to grease, it will be taken care.

Thanks for the tips.

www.skf.com/skf/productcatalogue/jsp/viewers/productTableViewer.jsp?&lang=en&tableName=1_6...3&startnum=14 -

The bearing clearance is 0.1 mm which is reccomeded by OEM.

We have checked the grease and found to be OK. No traces of excess grease obsereved.

Are you saying that you have a large (up to 50%) of the cap empty for expansion?

The bearing clearance is 0.1 mm which is reccomeded by OEM

You say this is a C3 bearing. I repeat, the radial clearance should be 0.2 to 0.26. I do not know to which OEM you refer, but SKF gives these clearances for this spherical roller bearing. Over tightening of tapered sleeves is a common fault and can result in high temperatures and premature failure.

GA.

100% correct. In fact he may need to take out as much as 50% of the amounts he has been using up to now.....there should be a large empty area for the grease to get squeezed out to the first time the motor starts after the bearing has been greased.

When I had a problem like this first I would go back and look at any previous break downs on that machine and try to think if maybe I had missed something when we made that repair.

These bearings will require a very good alignment to the shaft. If the bearing mount has shifted or is loose due to accident, vibration, or improper maintenance activities this could cause the heating problem.

If the taper bore on the shaft is dinged or there is an embedded chip that causes misallignment and poor seating this will create heat and failure. Working the taper with a good honing stone will cause you to detect and help you correct these type of faults.

Sincerely,

Mr. Gee

i had something similar problem of brg. in my pump. after long analysis and hard work we realise that brg hsg was welded inside. please check for that or if you have another pump try its hsg. if its ok then machined problematic hsg. in one setting.

We have checked the levels of the bearing housing ( both drive and non drive ends ). the levels are OK.

The housings are spray welded as it had some pitting marks. The pitting marks had occured due skew in the bearing which had damaged the end cover also.

Now since, housings are OK we have fitted with new bearings & sleeves, we are yet to start the machine.

I seek your suggestion as someitmes i doubt if i have missed out any check point.

Another thing that bears checking is the proper axial location of the bearing at installation. I would be looking at the installation process closely since there have been failures of replaced bearings.

If the inner and outer races are not at the correct axial location along the shaft, internal rubbing or odd loads will be passed to the bearing and cause overheating. This can be a little deceiving since this does not cause an overload condition of the radial loads.

I would also watch the crusher operate to see if I could pinpoint any outside problems that could cause the bearing problems. Does the crusher operate with any unexpected roughness that would pass multiple impact loads to the bearing?

When the failed bearing is inspected what is it telling you? Likely the original finish of the roller elements is a "matt finish". A shiny finish usually tells what area of the element was wearing. Do the races have any burnelling? Does the temperature of he bearing go up under no load conditions (no product in the crusher) or only while crushing. This process of investigation will likely yield an answer to your dilemma.

Firstly, be sure of your sensors functionality. If the bearing clearance and specified grease is as they should, and it is the non-drive end of the shaft that houses this bearing assembly, check the temerature probes, then make sure the shaft faces no de-centering/lateral loads during operation (this could be due to insufficient shaft support throughout).