Late summer is traditionally the heyday for parties and festivals - not infrequently accompanied by a not inconsiderable thirst for beer among the visitors. To prevent the queues at the beer stand from exploding, One Two Beer GmbH from Vienna has now developed an automatic system for particularly efficient beer tapping. At its heart: a mobile dispensing head that moves to the bottom of the cups and enables filling in five seconds without foaming over - built with a lubrication-free, hygienic, and durable threaded spindle of the dryspin series from igus, the innovation driver for plastic solutions from Cologne.

Runs like clockwork - even without lubrication

As simple and elegant as the beer robot may appear on the outside, its construction was a design challenge, according to Tamás Kozma, Chief Information Officer at One Two Beer GmbH: "To enable tapping within seconds, for example, a fast linear guide with as little friction as possible was essential." The system had to function accurately to a tenth of a millimeter, be as compact as possible for fast transport, and be insensitive to the harsh festival environment - including dust, high temperatures, and condensation. "Since our machine operates in the food sector, a 100 percent lubrication-free application with FDA compliance was also crucial for us," says Tamás Kozma. The company's engineers finally found a solution that met these requirements at igus: a complete linear guide unit consisting of a compact threaded spindle and threaded nut from the dryspin series and a matching stepper motor.

Hygienic and trouble-free dry running thanks to high-performance plastic and stainless steel.

And this is how the linear guide from the Rhineland works: The tap is mounted on a flanged threaded nut of the dryspin JFRM series. If the NEMA-23 spindle stepper motor now turns the spindle, the tap moves up or down. Basically, a simple system. However, with some special features: The threaded nut is made of an FDA-compliant high-performance plastic. A material with self-lubrication that enables low-friction dry running. The advantage is obvious: unlike lubricated metal variants, the polymer nut does not run the risk of becoming a dirt magnet due to lubricating grease. It is also easy to clean, whether with water or high pressure. The linear guide is hygienic and mechanically trouble-free. The combination of plastic and stainless steel also prevents corrosion. Thanks to the elimination of relubrication work, there is no need for any maintenance.

Threaded spindle achieves efficiency of 82 percent

But not only corrosion resistance and dirt insensitivity lead to a long service life of the linear guide. Equally decisive: igus has enlarged the thread edges of the nut in dryspin technology by a factor of 1.3. Likewise the width of the thread of the spindle. Due to this enlargement of the thread edges, more high-performance plastic is involved in the power transmission. And thus more material that is optimized in terms of friction and wear. "Through this asymmetry, we have managed to extend the service life by around 30 percent compared to symmetrical trapezoidal threads," says Torben Hendricks, head of the dryspin screw drive business unit at igus. In addition, he says, the flank angles of the threaded nut and spindle are flattened. "As a result, we achieve an above-average efficiency of 82 percent."

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