FEATURE LINEAR MOTION


Meeting the demands of positioning operations


With accurate, reliable and cost effective linear measurement essential for today’s automated machinery and systems, a new solution has been developed that can match the requirements of many common positioning operations. Dieter Winger from Parker Hannifin explains


W


hile almost all modern automated


machines and systems require precise, reliable and cost-effective linear measurement, most common industrial applications do not require micron- level accuracy. However, for engineers looking for a suitable linear measurement system, there are few truly viable options available. Many of today’s solutions may be


considered too expensive, too complex or are overly specified, while low-cost alternatives can quickly reach their limits when longer measuring lengths are required. Such factors apply to systems such as glass scales, potentiometers and magneto-strictive systems. Although offering high accuracy, many


optical systems are over-specified and too costly for the task. Most common industrial applications do not demand accuracies of a thousandth or even hundredth of a millimetre. Added to this, in terms of environmental performance, the susceptibility of optical systems to the ingress of contaminants can be an issue. With potentiometers, factors such


as extreme temperatures, vibration, wear and susceptibility to foreign matter are all well documented issues. Magneto-strictive systems also suffer from temperature effects, not to mention sensitivity to shock and potential inaccuracy over shorter distances of less than 100mm.


A NEW SOLUTION The shortcomings of existing solutions sometimes precludes them from use in particular applications. So, with the need for an alternative solution, Parker Hannifin has introduced the Sensoflex SFI-plus measuring system. Simple in design, cost-effective and able to provide a resolution of 0.1mm, this new technology can match the requirements


16 NOVEMBER 2018 | DESIGN SOLUTIONS of many common positioning operations. The possible objection, that


this measurement accuracy is insufficient, overlooks the fact that, in most cases, no higher accuracy is required. Designed for linear and non-linear


rotary motion, Sensoflex SFI-plus functions reliably within pneumatic, mechanical, electrical and hydraulic systems environments. Typical applications to benefit include conveyor and storage technology, lining work on wood or plastic machines, automatic cut-to-length machines, and worktables and transportation carts. Two principal components make


up this contactless magnetic length- measuring system: a 10mm wide, self-adhesive magnetic scale, and a reading/sensing head with connection to an external control unit. Contactless, and thus wear-free,


scanning is carried out magnetically. In terms of operation, the read head converts the magnetic poles into electrical signals that are processed by downstream


Designed for linear and non-linear rotary motion, Sensoflex SFI-plus functions reliably within pneumatic, mechanical, electrical and hydraulic systems environments


counter inputs, using a PLC, PC or digital counter. Two pulsating, 90˚ out-of-phase counter signals (phase A/B) are provided with a 0.1mm resolution (optionally 1mm). The counting direction can be determined automatically from the phase variance of the counter signals. Signal integrity is maintained even at travel/displacement speeds of up to 10m/s.


THE BENEFITS The cost-effective nature of such a solution stems from the fact that the scale itself is little more than a magnetised strip of tape adhered to the mounting surface with double-sided


adhesive tape. A stainless steel band provides not only the optical function but also the protective function of the measuring tape. Further economies are achieved


through quick assembly and minimal time required for wiring; not to mention that the system can replace the need for up to 10,000 switches per metre. Of additional benefit, the system is


* Dieter Winger is the product manager for Parker Hannifin, Motion Systems Group/ Pneumatic Division/ Actuators Business Unit


compact as it can be mounted directly on the actuator profile, while flexibility is derived through straightforward integration in existing systems. Universal application is facilitated through a choice of drive technologies and the fact that the system is suitable for almost any control or display unit with a counter input. User friendliness is enhanced via variable measuring lengths up to 32m; the only requirement is that the scanning head is also able to cover the entire travel distance. Lastly, the system is resistant to both vibration and impact, and offers a degree of protection to IP67.


Parker Hannifin www.parker.com


LINEAR TRACK HELPS REACTOR DECOMMISSIONING


Linear motion technology from Güdel is helping in the decommissioning of the Winfrith SGHWR (Steam Generating Heavy Water Reactor). The company’s part in the project is based on its reliable and durable TrackMotion Floor (TMF)


linear track, which can move industrial robots weighing up to six tons. TrackMotion robot slides use cam-rollers on flat guide rails to give an accurate, repeatable slide, which is highly resistant to ingress from environmental contaminants such as concrete dust and swarf. The track supplied is the TMF4 unit, with two independently driven carriages, which spans a distance


of 24m. A KUKA Titan 6-axis robot will traverse the track, visiting three distinct areas: the reactor chamber, a cleaning area and an area where operators can interact with the robot. The second carriage carries robot tooling – the robot will use a variety of different tools including a diamond impregnated saw, chippers and grippers. Unusually, in this application, the robot will be driven manually under remote control.


Güdel Lineartec (UK) www.gudel.com / DESIGNSOLUTIONS


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44