This page contains a Flash digital edition of a book.
FACTORY FOCUS SEALS & BEARINGS


SPLIT ROLLER BEARINGS Sourcing the best one for the job


Split roller bearings come in different designs and materials. Adrian Menzies of Revolvo describes some of the latest innovations and explains why all of its products are fitted with these as standard


S


plit roller bearings (SRBs) have been on the market for many years and


during that time their external appearances haven't changed a great deal but that isn't 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. Their 'split-to-the-shaft' design make them easy to install, maintain and replace 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. Over the past 20 years there have been


many innovations which have improved the reliability of SRBs and 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.


PRECISION 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 while absorbing lubricant and performing well in environments where lubrication is marginal. Unlike materials which often fail without warning, brass fails very gradually which makes it ideal for condition monitoring,


18 MARCH 2014 | FACTORY EQUIPMENT


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 cost saving potential of SRB technology.


INTEGRATED RETAINED CAGE CLIPS The raison d'être of SRB design is to simplify bearing installation and maintenance, therefore reducing the associated losses of extended downtime. Unfortunately some designs incorporate


a separate cage clip which clamps the two cage halves together. These are prone to falling out during assembly and inspection processes and easily be lost which can halt production as easily as any breakdown; greatly reducing the benefits of the SRB design. Revolvo developed an integrated


retained cage clip design which is firmly attached to one half of the cage via spiral pins and can easily be clipped onto the other half during assembly and removed with a flathead screwdriver during disassembly with no risk of loss. This speeds up the installation process


by effectively allowing the engineer a 'free-hand'. The benefits of reduced installation and maintenance costs are only relevant as long as the bearings offer similar performance (or better) in terms of reliability when compared to standard roller bearings. If a bearing is unable to survive in an industrial application it will never deliver improved efficiency and cost savings. The housing and support pedestal design must be able


Many site managers are wary of specifying SRBs in place of standard roller bearings in case expensive re-engineering is required


to cope with the mechanical stresses which will be applied in the application as well as any additional environmental hazards including corrosive material, submersion in water or extreme temperatures. Finding an SRB support pedestal which


is manufactured from robust cast iron (HT250- grade material to BSEN1561, 1997, for example) maximises durability; though the actual design of the casting also has an influence and Revolvo has optimised its design of support pedestal cap by incorporating stiffening ribs to significantly increase rigidity. Despite the undeniable benefits that


SRBs bring to industrial applications many site managers are wary of specifying them in place of standard roller bearings in case expensive re- engineering is required. Revolvo’s SRB offers a drop-in


replacement so there are no additional costs associated with changing.


SPECIFYING A SUPERIOR DESIGN Revolvo believes that it has a responsibility to the customer to offer the best available design, technology and materials across its entire range and without a cost penalty. This policy ensures consistent


performance and maximum ROI on a product that is designed to make savings by offering long-life and convenience in both operation and service.


Revolvo T: 01384 245370 www.revolvo.com Enter 313


/FACTORYEQUIPMENT


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48  |  Page 49  |  Page 50  |  Page 51  |  Page 52  |  Page 53  |  Page 54  |  Page 55  |  Page 56