There’s an old saying, “No crop without a field, no wheat without manure.”

But what is actually the cultivated soil that trailed agricultural machinery turns, loosens, and shapes?

From tillage to harvest, numerous trailed machines are used by farmers to support production. These machines, and even more so the bearings they rely on, are in direct contact with an often harsh environment.

What do we mean by a harsh environment? There are two types of contaminants:

– Solid contaminants: Soil, sand, stones, but also plant debris, and hay bale twine.

– Liquid pollutants: mud, manure, fertilizers, but also clean water for washing. These pollutants include many materials that are abrasive (waste, twine), but also corrosive (manure, ammonium fertilizers).

Let’s focus on soil, but first, what is it?

The soil on cultivated land contains solids (mineral and organic material), liquids, and gases. Pore space can account for up to 50% of the total volume, and this is filled with water or gas. Mineral constituents – or the mineral part – come from the physicochemical decomposition of the source rock. Organic components – the organic part – come from the decomposition of plant, animal, and microbial life (fungi, bacteria). This part forms the humus that plants need to grow.

If we look at the mineral part in detail, it is composed of elements of different grain sizes, including

– Chippings and stones (grain size > 2 mm).

– Sands (20 μm-0.2 mm)

– limestones (2 μm-20 μm)

– granular clay (< 2 μm).

All of these particles pose a risk to bearings.

How does this affect the bearings?

Grains and stones affect the outside of the bearing units (impact), but also the outside of the seals: Robust shields are used in front of the seals to protect them.

The smaller the grain size, the easier it is for the material to reach the seals. Sand is stopped with multi-lip seals, and for the finest particles that are not kept out by the outer lips of the seals, static grease barriers are placed inside the seal systems to catch any tiny particles that make it.

If that’s not enough, the process continues new lips on seals, then grease barriers.

Because of the wide variety of contaminants and to keep the machine working effectively, bearings must be fitted with seals designed specifically for this environment. There are many variations, depending on the position of the bearing in the machine (from single-lip to reinforced triple-lip seals to 8-lip seals). In addition, these parts must be mounted on ductile iron bearings to provide the necessary robustness against solid contamination.

Some machines can have up to 100 bearings, so it’s easy to see why the technical characteristics of these parts are so important!

For details, please contact: https://www.abdultraders.com/