Century Cement is reporting success with spit roller bearings on raw mill motor drives – so much so that it is now considering converting other applications at its Baikunth, Raipur, India site.The company had decided that the lifecycle of OE white metal bearings on the induction motors, even with pumped oil recirculation lubrication systems, was so poor that it was willing to buy new drive systems, if a lower maintenance motor bearing solution could not be found.
Adrian Menzies, Revolvo’s sales and marketing director, says that’s when his company offered long-life, low-maintenance SRB split roller bearings instead.Initially, grease lubricated solid spherical roller bearings were considered – in the hope that by using grease lubrication instead of oil recirculation should cut maintenance costs.However Century Cement was concerned that in the event of a bearing failure the replacement cycle would still involve significant down time as the motor shaft would need to be decoupled from the raw mill transmission, and lifted to enable bearing replacement.Revolvo’ solution, its SRB split roller bearings, offer the same grease-lubricated benefits of solid roller bearings, but bearing replacement times reduced by 90%, explains Menzies.
“When we were approached by M/S Bhavesh Engineering to propose an alternative solution, we were able to show that not only would SRB split roller bearings last longer and require lower maintenance resources, [but also] bearing replacement would be far quicker,” he says.“Once we measured the motor shafts, it was found that where the OE white metal bearings had been in service for over 20 years, some shaft bearing journal wear had taken place, probably exacerbated because of long-term lubrication oil contamination, which can often be an issue in cement plants,” he continues.”This meant that their motor shafts were out of tolerance for standard catalogue sized bearings. Fortunately, we are able to manufacture bespoke bearings in-house on short lead times, meaning that the replacement project was completed on schedule.”Since the SRB split roller bearings have been installed the application has run with far greater operational efficiency and economy, according to A Patini, executive president of Century Cement.”Since the installation, we have been very satisfied with the performance of these units,” he says. “Following the success of this project we will give consideration to the conversion of other applications within the plant as appropriate.”
source: Plant EngineerBearingNews