"Our sweepers do not surrender before any demand," Dipl.-Ing. (BA) Helmut Schmeh, Managing Director of FAUN Viatec GmbH, a member of the German Kirchhoff Group, clarifies on site in Grimma. "They cover every work area and ensure a convincing sweeping performance even under the most difficult conditions. " Whether as a street sweeper for the daily work in municipalities or in the most severe use on construction sites, as an airfield sweeper to clean the runway tracks, or as a manoeuvrable sweeper for small areas: they prove their ruggedness worldwide. They show their efficiency even in the steel factories, coal mines, or in the removal of oil residue. Niches such as rail cleaning or weed removal are also covered with matching accessory implements.

"We attach utmost importance to the development of practical solutions that have proved themselves day in and day out in harsh everyday use," says Helmut Schmeh. "We are committed to the manufacturing base in Germany. Our sweepers are customised developments, unique pieces that are designed in close agreement with the respective requirements on site.

To ensure the long-term durability of the sweepers, the company decided to use lubricant-free and thereby maintenance-free polymer plain bearings from igus® GmbH, Cologne. Bearings from different iglidur® materials are used especially at critical points such as the disc broom, for example, which is exposed to high shock loads almost constantly when sweeping the kerbstones, and in the rear lid area which is exposed to strong forces while opening and closing. In addition extreme dirt accumulation occurs in both places, which affects all areas.

The particularly wear resistant iglidur® W300 on the one hand and iglidur® Q for maximum loads on the other are fitted in the lifting links of the disc broom. For this purpose iglidur® Z, the material with the maximum surface pressure at present, ensures a strong wear resistance in the hinge and latch of the rear lid. "The dirt is discharged via the rear lid. For it gets really too dirty and possibly also wet. Since we started to use the polymer bearings, there is no need of welding in case of repair," Gerhard Gräbel points out. "If at all a defect would occur in the vehicle today, only the plastic bushings need to be replaced. This is simple in comparison. And we have the bushings in stock in the spare parts depot.

The issues such as maintenance-free and lubrication-free, dirt-resistance, low wear, easy maintenance and high compressive strength have played the crucial role in the decision in favour of the respective polymer plain bearings. As they are already at the cutting edge of technology for years in the area of ​​the rear lid and the sensitive pin/steel connections, which awkwardly called for regular lubrication, were successfully substituted the first day, a further development of the iglidur® Q material was considered for use in an area of the lifting links of the disc broom. It is iglidur® Q2.

The material is ideal for heavy-duty pivoting applications under extreme operating conditions. Wear-resistant and dimensionally stable at high loads, it ensures an even higher running time of the mounted sweepers. "Currently, we have a test vehicle running at a customer's site, whose results have not yet been finally evaluated," said the Managing Director. "If the calculations are correct, we switch to an even more wear-resistant material in a part of the disc broom.

The lifting links of the disc broom have been redesigned. Previously, the mechanical engineer relied on bronze or metal bearings with Teflon coating. "Our goal is to basically just put lubricant-free bearings on this extremely stressed point for all sweeper models in the future to guarantee our customers maintenance-free operation for years," the Managing Director clarifies the medium-term objective.

In the igus® test laboratory in Cologne, countless tests are conducted every year. The focus here are, for example, on material tests with high cycle rates, velocities, accelerations or demanding conditions. The components are provided partly by the customer. In addition to the normal surface pressures, the working processes of the disc broom, which pivot in and out continuously in the sweeping operation, are closely scrutinised in this application. Even the microvibrations of the vehicle has been simulated to represent the propelled sweeper.