NSK, Free guide to enhancing pump performance in mining
November 3, 2016
NSK has introduced a free guide entitled 'Bearings for Pumps and Compressors', which contains detailed information on the latest bearing designs and technologies, helpfully matching them to various pump types used commonly in the mining and quarrying industry.Optimised ball and roller bearing selection ensures that pumps and compressors are able to deliver increased performance and economy. Furthermore, choosing the right bearing can help reduce the physical size of pumps and extend the prime maintenance metric of mean time between failures (MTBF).
At mine and quarry facilities, pumps are a vital part of many extraction, handling and processing tasks, where any failure can result in a sudden loss of productivity and cause maintenance costs to spiral. Depending on the design, pump bearings can run under axial loads, radial loads or a combination of the two. In addition, running speeds can vary widely, as can lubrication conditions, but long life, or a high MTBF, remains a constant demand.
Pumps come in many variants, including centrifugal, piston, vortex, impeller and screw types. Depending on the media being transferred, each has its own requirements in terms of bearing design, which has resulted in NSK providing application-specific solutions.
A good example of this would be centrifugal pumps which require a bearing that can accommodate elevated axial loads while delivering minimal play. Here, NSK's recommended solution is its HR High Reliability Deep Groove Ball Bearing, which has larger rolling elements than standard deep groove ball bearings. This design can increase dynamic loading capacity by up to 19% and improve pump life.
Piston pumps are often required to operate under heavy axial and radial loads, with a need for precise bearing mounting and compatibility with the lubricating oil. In this case, NSK has developed a Cylindrical Roller Bearing with special L-PPS cage, which has superior heat and wear resistance, and offers chemical stability.
Extended running with minimum maintenance are principal demands placed on submersible pumps. However, the life of the pump's top bearing can be reduced significantly by creep, which is caused by the combination of a light radial load and a loose fit in the housing. Wary of this common industry issue, NSK has developed a creep-free solution that integrates double O-rings into the bearing's external surface.