Emerald Group Publishing Limited
Copyright © 2011, Emerald Group Publishing Limited
Article Type: New products From: Assembly Automation, Volume 31, Issue 3
Festo has launched two new series of mechanically compatible precision mini-slides – one pneumatic, the other electric – enabling OEMs and machine builders to mix and match different drive technologies with impunity (Figure 1). Both series of slides feature hardened steel guide rails, which are precision-ground together with the body after assembly, and use caged re-circulating ball bearings between the rails and the hardened steel slide. The overall effect is that the body and the slide jointly form the guidance system, conveying an exceptional level of rigidity to the design.
Both series of slides provide exceptionally fast and accurate positioning capabilities; all DGSL series pneumatic slides have a repetition accuracy of ±10 μm, while all EGSL series electric slides have a repetition accuracy of ±15 μm. The slides are ideal for applications demanding short and precise moves, and their low profile and mounting flexibility – they can be “piggybacked” and oriented in any aspect, including vertically – makes them especially suitable for use where space is limited. Principally intended for use in handling and assembly automation, both types of slides are likely to prove popular in the food processing and packaging industries, as well as in semiconductor and pharmaceutical manufacturing.
Festo’s DGSL series pneumatic slides are available with a choice of eight different sizes, from 4 to 25, and nine different stroke lengths – from 10 to 200 mm – depending on the model. The slides are double-acting, with the larger models capable of advancing and retracting at speeds as high as 0.8 m/s. The size 25 slide can produce up to 483 N of force when fed from a nominal six bar compressed air supply.
All DGSL series slides use an innovative piston technology that incorporates the guide tape and sealing element, together with an embedded magnet for position sensing purposes, in a single compact component. This results in less friction and air leakage, leading to steady and smooth movement, better speed constancy and a long working life. The slides also all offer a choice of three types of end-position cushioning – hydraulic, elastomer and adjustable elastomer – which can be set up very easily from one side of the unit’s body.
The new EGSL series electric slides offer users a choice of four different sizes, from 35 to 75, and five different stroke lengths, from 50 to 300 mm, depending on the model. The slides’ exceptional rigidity means that they can easily tolerate bending moments; two slides can simply be bolted together to form a cantilever axis, and all their surfaces feature centring rings to remove shear loads from the mounting bolts. The size 75 slide – which is large by any standard – can accommodate a horizontal load of up to 14 kg, and can generate up to 450 N of feed force.
All EGSL slides are capable of accelerating at up to 25 m/s2, and can achieve speeds as high as 1.3 m/s. To help put these figures in context, this typically means that a 200 mm EGSL-45 slide with a 6 kg payload can accomplish a complete positioning sequence in under 250 ms! The slides’ ball screw spindle is completely enclosed, rendering it impervious to contamination, and three of the four models offer a choice of spindle pitches to further simplify applications matching. The ball screw features an integral magnet, enabling inductive sensors or reed switches mounted on the outside of the slide’s body to be used, and easily adjusted, for position sensing purposes.
EGSL electric slides are fully compatible with Festo’s range of stepper and servo motors and controllers, and can also be used with third-party motors; Festo also produces a comprehensive range of motor mounting flanges and couplings, as well as slide mounting plates, axial mounting kits, optional cover kits and steel sensor flags for these slides.
Festo has also developed a powerful PC-based software tool, backed by native CAD models, to help machine designers and other potential users make best use of electric drive technology such as the EGSL slides. This software can be downloaded free of charge from www.festo.com/cms/en-gb_gb/index.htm