Statewide Bearings in conjunction with NSK and a Pilbara WA mine site selected a conveyor pulley that had ongoing spherical bearing problems. The standard sealed spherical roller bearings were replaced with sealed spherical rollers, see the preliminary report details.
Background:
NSK Sealed Spherical Roller Bearings were fitted in a pulley at a Pilbara WA Minesite, for the purpose of a trial. Pulley was installed in February 2014, as was removed in November 2014 due to an issue with the pulley lagging.
Bearings were then installed on to another pulley and put back in to service for approximately 2 years. Once again bearings were stripped from the pulley at in the presence of, Statewide Bearings and NSK personnel. Grease samples were taken and sent for analysis.
This is a preliminary inspection report, as bearings will be sent to NSK Japan for full analysis.
I have assumed that the floating and fixed bearings in the second term of service correspond to the first term of service.
Application Information:
Observations
Fixed Side
Inner Ring Bore
Good condition. Showing multiple sleeve witness marks due to re-use. (Photo 1)
Inner Ring Raceway
Good condition with no remarkable observations. There is a distinct 360º running roller trace. Seal running trace is uniform with little wear. (Photo 2)
Outer Ring OD
Normal fretting corrosion & housing witness lines at housing split surface. (Photo 3)
Outer Ring Raceway
Good condition. Raceway has been marked; A, B, C & D at 90º intervals. The load zone depicted in Photo 8 ranges from C to D positions showing little to no wear. Several small hard particle indentations apparent at the previous inspection are still present, but have not worsened or progressed. If anything, they seem to be less visible. (Photos 4, 5, 6, 7 & 8)
Roller –
Good condition, apart from small hard particle indentations observed in previous inspection. (Photos 9 & 10)
Free Side ‒
Inner Ring Bore
Good condition. Showing multiple sleeve witness marks due to re-use. (Photo 11)
Inner Ring Raceway
Good condition with no remarkable observations. There is a distinct 360º running roller trace. Seal running trace is uniform with little wear. (Photo 12)
Outer Ring OD
Normal fretting corrosion & housing witness lines at housing split surface. (Photo 13)
Outer Ring Raceway
Good condition. Raceway has been marked; A, B, C & D at 90º intervals. The load zone depicted in Photo 18 ranges from D to A positions showing little to no wear. Several small hard particle indentations apparent at the previous inspection are still present, but have not worsened or progressed. If anything, they seem to be less visible. (Photos 14, 15, 16, 17 & 18)
Roller
Good condition, apart from small hard particle indentations observed in previous inspection. (Photo 19 & 20)
Grease Analysis:
Nine grease samples were taken ‒
As expected, sample 9 had a high concentration of water. All other 8 samples registered a normal result.
Conclusion:
Both bearings are in good condition, and in my opinion would have had many more years of service. Grease analysis show that seals have been extremely effective.
The fact that indentations present since the first period of service have not progressed to flaking or spalling show that the Tough Steel™ Material that the bearing is made from has been very effective.
Found what you’re looking for?
Call today to speak to one of our team or
fill out the enquiry form for a prompt response
Statewide Bearings is committed to maintaining the delivery of our quality products and services to our customers.
As we continue to monitor the coronavirus (COVID-19) we assure you we are taking the appropriate steps to keep our employees, customers and the community safe.
We continue to actively follow the guidance from the World Health Organisation, each of our state and local government agencies and revise our processes in each branch to suit.