Profiled guide slides by Föhrenbach: Accuracy, speed and cleanliness in a new dimension

Löffingen-Unadingen. With new profiled guide slides, the Föhrenbach GmbH raises the benchmarks in the positioning technology to an unprecedented level. The types PFL, PCL and PKL stand for speed, cleanliness and accuracy in a new dimension - just as required by the customer needs.

PFL stands for a slide with conventional bellows, PCL means sheet metal cover (C for cover), and PKL stands for special protection against cooling media, as they are used in grinding machines in the form of water, grinding oil or emulsion. What all three slides have in common: More than ever before, they represent the Axis of Good.

Precision in a new dimension

The accuracy classes are now spread to four process accuracies. When it is equipped with appropriate measuring system, a slide in the Ultra-precision version can now be positioned in the range of 1 µm. The base plate is then designed in grey cast iron and the assembly plate in steel. The new accuracy class “Ultra-precision plus” is finally halving the extreme tiny value of 0.001 millimetres to 0.0005 millimetres (thus 0.5 µm). Due to the fact that the control unit of the Föhrenbach slides is compatible with the interfaces of nearly all measuring systems, this extraordinary repeatability is not bound to a particular system or a particular provider.

Speed in a new dimension

The profiled guide slides are equipped with ultra-modern linear motors which have a number of design advantages. As the motors are in-house developments of Föhrenbach, they are precisely adapted to the specific requirements. They are available in three versions. The motors improved again regarding the latest version allow - thanks to high continuous force - consistently high speeds and - thanks to a high peak performance - high acceleration values at the same time. Concerning standard, this means speeds up to 3 metres/second for all versions. If the motors and regulators are designed accordingly, up to 10 meters per second are possible with ceramic rolling elements. The high peak performance of the motors allows accelerations of up to 2.5 G with standard carriages and steel rolling elements. When using ceramics, this value can be doubled. In areas of application with frequent changes of the axial direction in particular, these values allow savings in time and thus significantly higher efficiency. The use of linear motors both supports the high positioning accuracy in all series and is required for the extreme values of the series Precision plus since no inaccuracies by gear backlash, toothed belt elongation, shaft torsion or resonance/hysteresis can occur. In the course of the process, the Föhrenbach linear motors further convince through their synchronization, which does now show - thanks to optimised magnets - deviations of less than 0.1 %.

Cleanliness in a new dimension

For machines with high coolant application, Föhrenbach has developed the profiled guide slide PKL. In this connection, guide elements, drive and measuring system are protected by a roof-bellow. The inclined roof shape supports the coolant run-off; the side cover reaches far below the guide rail. Thanks to the integrated linear motors, the slide only requires minimum installation space. The cooling system - a very clever solution - allows the high efficiency of the electric motors. For this reason, the PKL slide is ideally suited to meet even the highest demands in 3-shift operation under difficult ambient conditions. The new dimension of cleanliness can also found in the optimised lubrication. Regarding the lifetime lubrication, the carriages are lubricated during the assembly operation; re-lubrication is carried out using reservoirs. The correct lubricant quantity is delivered, which means no need for maintenance and the avoidance of problems caused by excess lubricant. With regard to short strokes in particular, the solution via proportioning valves displays its advantages. The profiled guide slides are thus suitable for the application in the clean room and comply with the appropriate certification standards in the automotive sector.

An overview of further improvements

 The development of a special attachment kit allows fitting of a clamp on the front. Clamping elements, which are operated by spring force, with pneumatic solution are exclusively used

 The profiled guide slides are available in four new sizes in order to meet requirements regarding installation space and stiffness in an even better manner

 In the standard, the slides are possible up to a stroke of up to 1600 mm - depending on the width of the base plate.

 Geometrically improved base plates facilitate the assembly of measuring systems; surfaces are available in cast iron either untreated or chemically nickel-plated, or aluminium (anodised)

 A large number of measuring systems working absolutely or incrementally can be attached directly to the slide - without any further precautions

Conclusion:

With the new, significantly improved slide systems of Föhrenbach, the users can enter new accuracy classes. At the same time, the variety of new sizes, the selection of powerful motors and the high process speeds make it possible to use the slide systems in virtually every application - due to the new PKL line even under heavy coolant application.