Mechanical Technology January 2015

⎪ Power transmission, bearings, bushes and seals ⎪

Bearing developments for extended service BMG’s bearings division – which has secured exclusive supply, service and distribution agreements with leading manufacturers, including

NSK and NTN – introduces the latest technologies, trends and products to the local market on a regular basis to better meet required demand.

These spherical roller bearings, with a 25% greater dynamic load rating than previous models, have a running life nearly double that of conventional bear- ings of the same size. The maximum limiting running speed has improved by 20% and a special cage design eliminates the need for a guide ring, allowing for the placement of additional larger rollers, which in turn increases load capacity. During rotation of conventional spherical roller bearings, slip between the raceway and roller causes fatigue, which eventually leads to flaking. To counter this, NSK has developed a special treatment on the surface of the outer ring that improves traction of roll- ers and controls the rotational speed of these rollers. In addition, a nitriding treatment on the surface of the cage, which forms a fine, hard and more uniform surface, reduces cage wear in harsh operational conditions. BMG, which has grown significantly over the last 40 years, has over 120 outlets throughout Southern Africa and continues to expand on the continent. The company’s extensive range now encompasses bearings, seals, power transmission components, electric and geared motors, as well as belting and fasteners. BMG also distributes filtration, hydraulics and pneumatics systems, tools and equipment. Ten specialist divisions, with ad- vanced technical skills, support the company’s commitment to applying technical knowledge and depth of ex- perience, to maximise the efficiency and profitability for every customer. Through its critical focus on entire production processes, BMG’s extensive range of quality branded components, engineering solutions and technical ser- vices, optimise productivity and enhance process plant operating reliability. q

“ R ecently launched spherical roller bearings for indus- trial machinery, include the NTN Ultage series and the NSKHPS series. NSK has also developed new high capacity cylindrical roller bearings – the EW and EM series,” says Rouff Essop, general manager, bearings division, BMG. “Standard bear- ings have been developed by manu- facturers, employing new technologies and materials, to produce spherical and cylindrical roller bearings that offer extended service life, greater reliability and improved ease of use” he adds. WA-type NTN Ultage sealed spheri- cal roller bearings, based on the inter- nal design of NTN’s standard EA-type spherical roller bearings, have larger roller diameters and the maximum number of rollers, which gives them the industry’s highest load capacity. The rollers in these bearings are guided with window-type pressed steel cages. The new WA series, with a light, compact design, offers up to five times longer service life than previous models. Contact type rubber seals prevent the intrusion of foreign matter and a spe- cially designed lip structure maintains constant contact pressure of seals to secure the dust-proof capability, even Above: NSK is continually developing products with greater strength and higher accuracy. The NSKHPS range incorpo- rates a new compact internal design and the latest materials and manufacturing technology. Right: NTN Ultage WA-type sealed spherical roller bearings, with larger roller diameters and a maximum number of rollers, provide the industry’s highest load carrying capacity.

in under-aligned conditions. NTN sealed spherical roller bearings, which are pre-lubricated with long-life grease, do not require cleaning or greas- ing when being mounted. An oil groove and holes on the outside diameter of the outer ring, ensure there is adequate greasing into the inside of the bearing. New developments of NSK EM and EW cylindrical roller bearings include a greater number of larger rollers than conventional bearings, to offer higher load ratings. One piece, high strength roller guided machined brass cages ensure improved performance and reduced wear. The service life of these bearings has been doubled. Noise and vibration levels have been reduced by about 70% and the limit- ing speed has been increased by up to 25%. A special pocket profile enhances roller guide accuracy and ensures im- proved lubricant flow. NSK is continually developing prod- ucts with greater strength and higher accuracy. The NSKHPS range incorpo- rates a new compact internal design and the latest materials and manufacturing technology.

Mechanical Technology — January 2015

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