Robust plain bearings for heavy duty use in cultivators in agriculture

Lemken GmbH und Co KG is a family-run company that specialises in the manufacture of agricultural equipment for soil cultivation, sowing and plant protection. One of the manufacturer's product areas is stubble working appliances, so-called cultivators and short disc harrows. Today, these are primarily used for conservation tillage and stubble working. With the "Karat 9", Lemken offers an intensive cultivator that penetrates between five and 30 centimetres deep into the soil and thus optimally incorporates organic matter. During operation, there may be large stones in the ground in the path of the tractor and its soil tillage implement, which must not hinder the work process. For this reason, the Karat 9 is equipped with overload elements, whereby the tines, which work in the soil during normal operation, automatically move backwards and upwards and then automatically return to the working position. Depending on the size of the cultivator, the metal bearing solution used to move the tines had to be lubricated for up to 1 hour a day in order for the bearings to work properly. If the numerous lubrication points, depending on the working width, were not sufficiently lubricated, the resulting lack of lubrication led to considerable problems with corrosion and greatly increased wear of the bearing point, which ultimately resulted in damage to shafts and housing bores.

Thanks to the use of lubrication-free igus plastic plain bearings, the overload element now works without maintenance. The iglidur high-performance materials require no relubrication as the bearings contain solid lubricants. This helps the farmer save valuable time. Unlike metal bearings, where the lubricants cannot be distributed evenly and only the same points are stressed, plastic plain bearings can play to their strengths here. The pivoting movements cannot affect them as much and there is no danger of lubricants being displaced. Another advantage is the bearings' dry operation as no dirt can adhere to them. Their high stability and the fact that they can easily withstand the high forces in the cultivator's overload element make them significantly more reliable. Lemken also saved costs thanks to the more favourable procurement expenses and the plain bearings' increased service life.
igus can draw on 47 catalogue materials for a wide range of requirements, including those of heavy-duty applications found in the agricultural sector. However, the Karat 9 cultivator already features plain bearings made from the all-rounder iglidur G, which can withstand a compressive strength of 80MPa.