Power Transmission
Adrian Menzies looks at some of the latest innovations in split roller bearings.
Adrian Menzies examine une partie des dernières innovations en matière de roulements cylindriques à deux parties.
Adrian Menzies sieht sich einige der neuesten Innovationen in Sachen geteilte Rollenlager an.
What makes a superior split roller bearing?
S
plit roller bearings (SRBs) have been on the market for many years and during that time their external appearances
have not changed a great deal, but, that is not to say that all designs are equal. New design techniques and changes in materials mean that some bearings can last far longer in operation than others. So what features should end users be looking for, and are they available across the board? Since their invention, SRBs have
been used in demanding applications across various industries to reduce the cost of installation, routine maintenance and replacement. Thanks to their unique, ‘split-to-the- shaft’ design it is easy to install, maintain and replace SRBs without having to lift or remove the shaft from the drive to obtain access. Because of this improved access it is possible to reduce production losses caused by maintenance downtime by as much as 90%, which means that most SRBs pay for themselves many times over during their life. However, as with all
The raison d’être of SRB design is to simplify bearing installation and maintenance, therefore reducing the associated losses of extended downtime.
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mechanical components, some designs are better than others. Over the past 20 years there have been many innovations which have improved the reliability of split roller bearings as well as the ease with which they can be installed. Despite offering significantly improved performance, many of these features are missing from some products on the market today. This can lead to reduced
service life and frustrations during the installation stages.
Machined brass cages
Recent studies have shown that, for ultimate reliability in bearings of this type, precision machined bored pocket brass cages offer the best results and outperform pressed steel, aluminium and polyamide materials. Brass offers high rigidity, high strength, resistance to shock loads, can be used at high temperatures whilst also absorbing lubricant and performing well in environments where lubrication is marginal. Unlike other materials that will often fail without warning, brass fails very gradually, which makes it ideal for condition monitoring, allowing preventative measures to be taken and avoid unpredictable failures. By fully machining brass cages it is
possible to deliver improved bearing reliability by ensuring accurate guidance of the rolling elements. When compared to their pressed steel, cast aluminium, or moulded polyamide counterparts it’s easy to see how the CNC bored pocket brass cage prevents roller skewing; a condition which can lead to edge loading on the trackway and reduced bearing life. Skewing is a serious cause of premature failure in bearings of all sizes, so the use of fully machined brass cages makes a significant improvement to the overall reliability, and therefore cost saving potential, of split roller bearing technology.
Simplified installation
The raison d’être of SRB design is to simplify bearing installation and maintenance, therefore reducing the associated losses of extended downtime. For this reason it is essential that the bearings can be assembled simply and without inconvenience. Unfortunately some designs
incorporate a separate cage clip that
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