Trailer hub oil seals play a critical role in maintaining the integrity of the wheel hub assembly on trailers and other towed vehicles. These seals are designed to prevent the leakage of lubricating oil and the ingress of contaminants, ensuring the proper functioning and longevity of the wheel bearings and other internal components. The trailer hub oil seal is typically positioned within the hub assembly, creating a barrier that helps retain the lubricant and protect the bearings from moisture, dirt, and debris.

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What are Oil Seals - Guide to what an Oil Seal is used for

Floating oil seals are essential components used in various industries to prevent leakage of oil and other fluids. These seals are designed to float on the surface of the oil, creating a barrier that keeps the oil contained within a system. They are commonly used in gearboxes, hydraulic systems, and other machinery where the potential for oil leakage is a concern.

Requirements of the shaft
Even more important than a correct interference fit of the Oil Seal is a perfectly smooth shaft in the region of the seal, particularly if shaft surface speed is high and the medium to be sealed is under a certain amount of excess pressure. The surface roughness of the shaft depends on the average profile depth Ra of the tool marks caused by the machining process. Oil Seals made of PTFE require, independent of the surface speed, a surface roughness of between 0,1 to 0,2 mm, because PTFE has less wear resistance than rubber seals. For normal circumstances, the shaft in the region of the seal must have a surface roughness of approximately:  To summarize, the surface of the shaft in the region of the seal should not have noticeable machining marks. For pivoting shafts and other difficult or critical sealing applications, it is recommended that Oil Seals with a helical groove hydrodynamic pattern, which has a pumping effect, be used. When grinding and polishing, an axial movement of the grindstone along the shaft must be avoided in order to prevent machine lay. 

ERIKS type R (type A according to the DIN standard) is identical in shape to type M, but has a rubber outer case with metal reinforcement on the inside. The rubber creates a good seal in the housing, even if the housing has suffered minor damage or is not in its best condition for other reasons. The RST version has a dust lip. These types are often chosen to replace a type with a metal outer case because they are easier to install and can cope with minor damage to the groove, such as scratches.