For applications where reductions in weight are paramount, IKO offers the cost-effective precision linear slide range. Made from stainless steel, and available in recirculating (BSR) and non-recirculating (BSP) options, this range is highly flexible. It features a simple two-row, four-point contact structure, high motion accuracy and stable load carrying capacity.
This can be further enhanced using a built-in rack and pinion system in the BSP variant (BSPG) for applications where there is potential for cage creep. This phenomenon is generally seen in many vertically-orientated, high-speed applications, and IKO’s design reduces the chance of this occurring.
For applications that may receive fluctuating and complex loads, but still need to see consistent repeatable results, the BWU range may be more appropriate. The high rigidity, precision linear slide units offer design engineers the possibility of adding a secure mounting position that can handle loads of up to 12,100N. They are also exclusively made of stainless steel, making them suitable for potentially corrosive environments or cleanrooms. In addition, they are suitable for applications where rust prevention oil is not preferred.
For designers and machine builders looking to increase load ratings further, while keeping the overall machine size to a minimum, IKO can then offer its crossed roller ways (CRW). This range is available in three different variants, including a rack and pinion option (CRWG) and a heavier-duty variant that increases the strength of the internal components (CRWH). These products all utilise cylindrical rolling elements instead of ball bearings, and provide increased load rating capacity and improved rigidity. This, in turn, increases the stability of the overall product.
Despite the variation in materials and structure, all of the models share a similar design. With single linear caged bearings consisting of ball or roller elements running along inner and outer tracks. These bearings are arranged in parallel, one on each side of the slide, to support the weight of the table (or carriage) and its mounted load as it moves.
The various designs all provide precise accurate motion, normally over short stroke lengths. In the BSP, BWU and CRW ranges, this motion is further enhanced by their non-recirculating design. Due to the compression and release of the rolling elements as they pass in and out of contact with the raceways seen in recirculating designs, there is no chance of the balls causing any background distortions in the data gathered. For the same reason, the bearings run very quietly. In addition, maximum speeds of 50m/min can be achieved.
A further advantage of the precision linear slide units’ design configuration is extremely accurate motion. Parallelism of the BSP limited linear motion type precision linear slide units at the table centre is 3micron up to 18mm travel, and 6micron up to 80mm travel. Comparable figures for the BWU model are 4micron up to 50mm length, and 6micron up to 120mm length. CRW & CRWG units when compared to BWUs have increased running accuracy at the centre of the table. For example, as the required stroke length increases this difference can improve by up to four times.
Turning to the applications, smooth and precise motion is a key requirement of linear ways when used for travelling elements of precision instruments. For example, the semiconductor manufacturing industry uses a three-axis (XYZ) micro-positioner for final computer chip placement. What is required is a stable rigid mechanism, with no bending moment. Such machines often use micro-step stepper motors or servomotors as the drive component, which, when paired with linear encoders, can provide extremely high-resolution adjustments for processing microscopic features. Such motions can be so small that they are invisible to the naked eye.
While IKO prizes quality over pricing, one thing for customers to keep in mind when buying precision linear ways is how many parts are included. This is particularly important when specifying the CRW range. While, for historical reasons, many competitors sell these parts in what is essentially only half of a full set required for any motion profile – two ways with one cage and rolling elements – IKO always sells CRWs as a complete kit: four ways with two cages and rolling elements. For that reason, a price that is perhaps 75% higher for an IKO full set (for example) when compared to a competitor’s set might prove to be a more cost-effective option, as two sets of the competitor’s product would be needed to make up the same quantity as IKO’s offering.
By offering the right bearings in an installation-friendly manner, IKO aims to meet its customers’ needs – and often exceeds them.
Contact IKO UK today at 01908 566144, or email enquiries@iko.co.uk to discuss your motion control needs. Alternatively, visit the IKO website.
