BEARINGS
Zero Failure Bearing Services Bethal, supported by SKF, has been supplying a key customer in Mpumalanga’s coal mining industry with over 400 bearings which have delivered zero failure whilst operating in a highly aggressive application.
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he coal mining industry is a notoriously highly corrosive environment. Continuous water and coal dust contamination as a result of the coal mining and conveying processes play havoc with machine reliability giving rise to frequent downtime and subsequent costly production losses. “Our customer was facing Mean Time between Failures (MTBF) on their tail end pulley bearings every two weeks and on their sizer crusher bearings every three months,” explains Marchant Taylor, SKF Regional Sales Manager - North East Region. Lubrication difficulties further compound the situation affecting equipment and component reliability.
Triple the protection
Working in close cooperation with SKF, the team from Bearing Services Bethal stepped in and presented the SKF triple-barrier solution for the conveyor tail end pulleys and the
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BULK HANDLING TODAY
August 2019
two scroll sizer crushers, which were replaced with Sealed Spherical Roller Bearings (SSRBs). Marchant explains that the triple-barrier solution which comprises a SSRB and labyrinth seal combination is the ultimate sealing arrangement to protect bearings from contamination in highly contaminated areas. The SSRB and the Labyrinth seal offer three barriers through which contamination must penetrate before it will reach and subsequently affect the bearing.
The triple-barrier solution comprises a SSRB and labyrinth seal combination which is the ultimate sealing arrangement to protect bearings from contamination in harsh areas The solution presents inner seal protection from the sealed spherical roller bearing itself which is installed in a housing with a 70 to 90% grease fill that completely isolates it from the sealed bearing, forming the second barrier. The third barrier is formed by the Labyrinth multi-stage labyrinth cartridge seal that is used to seal the housing from outside contamination which has its own greasefilled sealing configuration. A sealed-for-life bearing is also included.
