DBH seals in agriculture: components for combine harvesters, seeders, bucket elevators and storage plants

DBH radial seals are seals that prevent lubricant leaks and the ingress of contaminants in rotating shafts. They are mounted in fixed housings and their flexible lip bears against the shaft, keeping oil or grease inside. In agriculture, this function is critical because machines work in environments with dirt, dust, crop residue and moisture. A seal in good condition extends the life of bearings and gears.

In combine harvesters, DBH seals are found in transmission boxes, augers, rotors and traction systems. In seeders, they protect the metering shafts and the contact wheels. Bucket elevators and grain elevators use them in their pulleys and bearing housings. Storage plants need them in conveyors, dryers and extractors, where an oil leak can contaminate the grain.

We supply DBH radial seals in different sizes and materials. When ordering them, it is advisable to have clear the shaft diameter, the housing outer diameter and the width. With that data we quote the right seal for your equipment.

Combine harvesters concentrate many sealing points: control box, unloading auger, threshing rotor, fan and hydraulic system. Each one has seals of different sizes, and a mistake when replacing them can leave the machine stopped in the middle of harvest. Therefore, when removing a seal, it is advisable to note the measurements engraved on the body or measure the shaft and housing with a caliper.

If the seal still has the marked code, such as 5999, 8888 or 8969, that data allows exact replacement. If the seal is damaged and cannot be read, it can be measured: inner diameter (shaft), outer diameter (housing) and width. With those three measurements, we quote the corresponding DBH seal.

A common mistake is ordering only by shaft size and forgetting the outer diameter or width. Another is not checking the condition of the shaft: if it has scratches or wear, the new seal will not seal properly. Before mounting, clean the housing and lubricate the lip with the same oil or grease as the system. This way you avoid premature leaks and unplanned stops.

In seeders, DBH seals are used on the seed and fertilizer metering shafts, on depth-limiting wheels and on seeding units. These components rotate at low revolutions but are exposed to fine dust and agrochemical residues. A seal that loses grease allows dirt to enter, which accelerates wear of bushings and bearings.

To identify the correct seal, you can look for the code on the original seal or in the seeder parts manual. If that information is not available, measure the shaft and housing. Codes such as 5999, 8888 or 8969 are examples of DBH radial seals. You can also send a photo of the seal with a ruler next to it so we can help you identify it.

When replacing seals in seeders, check that the lip is oriented correctly: toward the lubricant side. An inverted installation causes immediate leaks. It is also advisable to check the condition of neighboring seals, because if one failed due to contamination, others are likely compromised. Replacing them together reduces stops during seeding.

Bucket elevators and grain elevators have shafts at the head and at the foot, mounted on bearing housings with bearings. Seals protect those bearings from grain dust, which is highly abrasive. They are also used in the gearmotors that drive the bucket elevator. A defective seal allows dust to enter the bearing and destroy it in a short time.

In these equipment, DBH seals usually work with grease, so the lip must retain it and at the same time prevent the ingress of particles. When ordering them, it is advisable to indicate whether the equipment works outdoors or under cover, because that influences the seal material. Codes such as 5999, 8888 or 8969 are examples of DBH radial seals.

A frequent mistake is not cleaning the housing well before mounting the new seal, leaving remains of the old seal or dirt. That can misalign the seal and cause leaks. You also have to strike evenly, using a tube of the seal diameter, never directly on the lip. If the shaft is marked, it can be repaired with a wear sleeve or the part can be replaced.

In storage plants, seals are used in belt conveyors, augers, screws, fans and dryers. These equipment operate many hours per day during harvest, and an oil leak can contaminate the grain or cause a fire. Therefore, preventive seal maintenance is key in post-harvest.

DBH seals are identified by the code, such as 5999, 8888 or 8969, or by the measurements. In storage plants, it is advisable to identify in advance the seals of critical equipment. We quote the DBH seals you need, with the code or the size.

When mounting seals in conveyors, check the alignment of the shaft and housing. Misalignment causes uneven lip wear and leaks. It is also important to use the seal with the appropriate lip material: for high temperatures in dryers, viton or silicone lips are recommended. Ask us about the right option for your application.

To quote a DBH seal, the ideal is to have the exact code, for example 5999, 8888 or 8969. If it cannot be read, measure three things: inner diameter (the shaft where the lip bears), outer diameter (the housing where it is mounted) and width. These measurements are taken in millimeters with a caliper. With those three numbers, we quote the correct DBH seal.

It also helps to send a photo of the old seal, from both sides, and if possible a photo of the place where it is mounted. That helps us confirm the type of seal and the material. If the seal has engraved marks, even if blurry, it is advisable to pass them all on. Sometimes the code includes letters that indicate the type of lip or material.

A common mistake is measuring only the outer diameter and assuming the inner one. Another is confusing the total width with the lip width. You also have to consider whether the seal has an additional dust lip or spring. All those details influence the selection. Send all the information you have and we will respond promptly.

The most common mistake is ordering the seal only by shaft size, without verifying the outer diameter and width. That leads to receiving a seal that does not fit into the housing or does not seal. Another mistake is not checking the condition of the shaft: if it has wear or scratches, the new seal will fail soon. The contact surface must always be inspected.

When mounting, many strike the seal directly with a hammer, deforming the casing or damaging the lip. A tube or driver of the outer diameter should be used and struck evenly. The lip must also be lubricated before mounting and the mounting direction respected. A seal mounted backwards loses oil immediately.

In agricultural equipment, contamination is the main cause of seal failure. Therefore, when replacing a seal, it is advisable to clean the housing well and check that there are no remains of the old seal. If the equipment works in extreme conditions, seals with an additional lip or special materials can be chosen. We advise you to choose the best option.