Big Savings Promised from Bearing Installation at Platinum Mine

Big Savings Promised from Bearing Installation at Platinum Mine Four years after installing a split bearing at a large conveyor belt at Anglo Platinum¡¯s Frank shaft in Rustenburg, the bearing supplied and fitted by OE Bearings is still running, saving the miner a significant amount of money, reports sectional engineer Dirk Erasmus. He estimates that the down time for a conventional bearing replacement, calculated at the time of replacement four years ago, could have ¡°run to more than R1-million¡±. The failed bearing is one of the main drive bearings and is positioned between the drive pulley and the driven half-coupling. Removal and replacement of the bearing would have necessitated the removal of the drive gearbox and half-coupling, which is a mammoth task. Once the bearing was replaced, the tedious job of realigning all the drive components still had to be done. This is time-consuming and the down time is estimated to be in excess of 24 hours. At a rating of 550 t/h, the loss in revenue could easily top the R1-million mark. ¡°We opted, instead, to fit a split bearing and contacted split bearing specialist, OE Bearings, which installed the bearing within four hours. ¡°It is interesting to note that the same bearing is still running smoothly, four years later,¡± adds Erasmus. This proves that split bearings, albeit a little more expensive, are cost-savers in the medium to long term, as well as being reliable. Erasmus remarks that initial modifications had to be done to the bearing base plate to accommodate the split bearings but the latest split bearings are now dimensionally similar to conventional bearings, thus no modifications are required. OE Bearings director Warwick Steinhobel says split roller bearings are two-and-a-half times the cost of good quality plummer block units, but that repair and installation times are much faster and they outlast standard bearings. ¡°This is a very important comparison to take note of although many people still seem unaware of it or forget it,¡± says Steinhobel. He says down time costs in industries such as Anglo Platinum are estimated to be between R10 000 to R500 000 an hour and this means that a fast swap-over of bearings when they fail is crucial for plant uptime.¡± Steinhobel adds that with split bearings, the bearings have a longer lifespan because they cannot be cross-located. The superior sealing arrangement also means a longer bearing life, maintenance time is reduced and accurate bearing condition is easily determined while the time required to fit a bearing is dramatically reduced, typically from eight hours to one hour.