New Bearings Sweep Well

“Our sweepers do not surrender before any demand,” Helmut Schmeh, Managing Director of FAUN Viatec GmbH, explains on site in Grimma, Germany. “They cover every work are and ensure an impressive sweeping performance, even when under the most difficult conditions.”

Whether for a street sweeper for daily use in municipalities, or for those used in extreme conditions like those found on construction sites, as an airfield sweeper for airline runways, or small, maneuverable sweepers for small areas, these types of sweeper systems prove their ruggedness around the world in an array of types and sizes. They show their efficiency even in steel factories, coal mines, or in the removal of oil residue. Niche areas, such as rail cleaning and weed removal are also covered with corresponding system accessory parts.

“We attach the utmost importance to the development of practical solutions that have proven themselves day in and day out under harsh everyday use,” says Helmut Schmeh. “We are committed to the manufacturing base in Germany. Out sweepers are customized developments; unique pieces that are designed in close cooperation with the respective site requirements.”

The rugged mounted sweepers are used for the daily work in cities and towns or for the most severe use on construction sites, in steel factories, in coal mines, as an airfield sweeper to clean the runway tracks, or as a maneuverable sweeper for small areas.

Critical points: Rear Lid and Disc Broom

To ensure the long term durability of the sweepers, the company decided to use self-lubricating, maintenance free plastic plain bearings from igus®. Bearings made from the various iglide® materials are used, especially focused at critical points such as those in the disc broom, for example, which is exposed to high shock loads almost constantly while sweeping curbstones, and in the rear lid area which is exposed to strong forces while opening and closing. Additionally, extreme dirt accumulation occurs in both places, which affects all areas.

The particularly wear resistant iglide® L280, as well as iglide® Q for maximum loads, are fitted into the lifting links of the disc broom. For this purpose, iglide® Z, the iglide® material able to stand the highest maximum surface pressure, ensures a strong wear resistance in the hinge and latch of the rear lid. “The dirt is discharged via the rear lid, which gets extremely dirty, and often wet. Since we started to use the plastic bearings, there is no need for welding in case of repair,” Gerhard Gräbel points out.

Still More Wear Resistant Material

The issues such as freedom from maintenance and external lubrication, dirt resistance, low wear, and high compressive strength have played a crucial role in the decision in favor of selecting the iglide® plastic plain bearings. After the success of switching the iglide® plastic bearings in the rear lid, a further development of the iglide® Q material was considered for use in areas of the lifting links of the disc broom using the iglide® Q2 material, which is ideal for heavy-duty pivoting applications under extreme operating conditions. Wear-resistant and dimensionally stable at high loads, the Q2 material ensures an extended service life for the mounted sweepers. “Currently, we have a test vehicle running at a customer’s site, whose results have not been fully evaluated,” said Schmeh. “If the calculations are correct, we will switch to this 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 a Teflon coating. “Our goal is to basically just put self-lubricating bearings on this extremely stressed point for all future sweeper models to guarantee our customer’s years of maintenance free operation,” Schmeh explained.

Microvibrations in the laboratory

In the igus® test laboratory in Cologne, Germany, countless tests are conducted every year. The focus here is, for example, on material test with high cycle rates, velocities, accelerations, and/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 scrutinized in this application. Even the microvibrations of the vehicle has been simulated to represent the propelled sweeper.

“The test results demonstrate that the more brittle new material will likely withstand the daily stresses even better in the long term,” the designer assures. “With it, the advantages for the machine operator are obvious. The rugged sweepers are economical in use over time with the simultaneous reduction of maintenance and service costs,” he adds.

Polymer bearings in the rear lid area of the mounted sweeper.

Polymer bearings in the disc broom area of the mounted sweeper.

From left: Gerhard Gräbel, Helmut Schmeh (both Faun Viatec), Thomas Sommerweiß (igus®).

Detailed view of the Faun Viajet 5 Allround mounted sweeper with 5 m³ structural volume.