Plain bearing unit incorporates roller for low-friction sliding

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Plain bearing unit incorporates roller for low-friction slidingigus is promoting its drylin WJRM hybrid linear bearing that both rolls and slides. This bearing, which is claimed to be unique, reduces the driving force significantly and is particularly suitable for applications such as machine guards, where there could be loads applied along and normal to the axis; other applications include manually adjustable partitions and locks, as well as light-duty handling tasks. This product will be featured on the igus stand at the 2013 Machine Building Show (NEC, Birmingham, 25/26 September).

Lubricant-free, the plastic sliding plain bearing pads ensure the hybrid bearing is robust, insensitive to dirt and humidity, as well as being lightweight and cost-competitive. The polymer rollers (dark grey in the photo), which are also maintenance-free, allow for easy manual adjustment of heavy machine doors and protective doors that can weigh up to 50kg. At a defined installation position, the roller bearing, which carries the main load, reduces the overall driving force by a factor of between four and five – which eases manual operation considerably, thereby improving a machine's ergonomics.

The principle of the installation position for the new hybrid bearing is such that the main load is on the roller bearing to reduce the driving force required; the plastic sliders (coloured cream in the photo) compensate for any lateral loads.

Bearing elements

drylin W is a versatile modular system made of hard anodised aluminium profiles, diecast zinc housings, stainless steel or aluminium and plastic plain bearings. The wide variety of options within this easy-to-install system enables engineers to make the optimum use of the space available. Combined with different carriage lengths, the rail widths permit many combinations. The four design sizes range from 6mm to a shaft diameter of 20mm.

All the drylin W guide systems work without lubricants as dry-running systems, which means that they do not have to be serviced during operation. The linear bearings are offered with the polymer sliding bearings iglidur J or iglidur J200. Both of these materials offer low wear and low friction values. In addition, they are resistant to chemicals, help to dampen vibrations and are impervious to moisture that might accumulate in humid environments.

The hybrid linear bearing design is based around the field-proven drylin W linear guide family. igus has modelled the new drylin WJRM system in such a way that the roller fits inside without increasing the overall design width, which remains at 18mm. Standard economic guide profiles can be used, which are available in three styles for 10mm diameter shafts – as individual rails for a flexible guiding distance or as double rails with centre spacings of 40mm or 80mm, which are self-aligning for speedy installation. The hybrid bearing housing is of blue-chromed diecast zinc.

New variant

A new version, the drylin WJRM double hybrid bearing, is being introduced at the Machine Building Show. This features a pair of rollers inclined at 90 degrees to each other that share the vertical load from the machine guard and take some lateral loads. While the diecast zinc housing has been enlarged slightly to accommodate the two rollers, the additional load capacity will be welcomed by machine builders designing large guards or sliding doors.

Follow the link for more information about the drylin WJRM hybrid bearing.

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