MECHANICAL COMPONENTS


IS THERE ANY DISTORTION IN THE MOUNTING SURFACE?


Distortion is one of the most insidious threats to a good mounting and can happen in several ways. Even a tiny piece of debris lodged between the bearing and the mounting surface during assembly can cause a major distortion, leading to load concentration in the bearing. A mounting surface that is out-of-flat is another hazard – the surface needs to be machined to the same accuracy as


the bearing mounting face. In addition, welding riser


pads should be thick enough to resist distortion during welding and flush against the base to avoid any gap below the bearing seat.


WILL THE BEARING BE PROPERLY SEALED AND LUBRICATED? It’s essential to keep out debris and


“Even a tiny piece of


debris lodged between the bearing and the


mounting surface during


FEATURE


assembly can cause a major distortion, leading to load concentration in the bearing”


corrosion to avoid excessive wear, high torque and stress concentrations, any of which can cause the bearing to fail prematurely. Specifying integral seals on bearings is a great way to accomplish this, as is incorporating shrouding to protect machine-cut


gears and bearings. Lubrication is another


key to reducing wear. Bearings are generally packed


with a suitable grease when they are assembled, and whenever grease is used, re-lubrication fittings should be specified.


HOW WILL THE BEARING BE STORED? When slewing ring bearings are prepared for shipment, they are usually given a light coating of preservative oil and packaged in protective paper. This provides adequate protection during short-term storage but not for long periods or outdoors. If a bearing sits for more than a year before being installed, it should be re-lubricated.


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Slewing ring bearings are ideal for use in heavy duty applications


R. A. Rodriguez www.rarodriguez.co.uk


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DESIGN SOLUTIONS | NOVEMBER 2018


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