Failure Analysis of Floating Oil Seals

Although floating oil seals have a long service life, they can fail for various reasons. Below is an analysis of the causes of floating oil seal failure.

Quality issues of the floating oil seal itself

The material, hardness, finish of the sealing surface, coaxiality of the conical surface to the reference axis, hardness of the rubber ring, and anti-aging properties all affect the sealing performance of the floating oil seal.

Installation issues of the floating oil seal

If the installation is not performed according to the correct steps and requirements, it can lead to deformation or damage of the components, causing the floating oil seal to fail. If the installation procedure is not followed, it is possible for impurities, debris, and other foreign particles to enter during the installation process, leading to leakage.

Uneven or excessive contact pressure on the sealing end face

The pressure on the sealing end face should be uniform and appropriately sized. Too little pressure reduces sealing performance, while too much pressure increases friction and wear on the sealing end face.

Design and manufacturing issues of the floating seal seat

The floating oil seal must integrate with the floating seal seat seamlessly. Whether the floating seal seat can perfectly match the floating oil seal directly impacts the performance of the floating oil seal. Therefore, manufacturing must follow accurate data provided by the manufacturer or the standards for floating oil seals.

Issues with lubricating oil

Using inappropriate lubricating oil can directly reduce the service life of the floating oil seal, causing the rubber ring to age prematurely and lose elasticity. The cleanliness of the lubricating oil also affects the formation of the oil film on the floating oil seal, thus affecting its sealing performance.

Impact of the operating environment: Construction machinery often operates in environments with high levels of mud and dust. External mud, dust, and other particles can infiltrate the internal space from the gap between the two floating seal seats and become compacted on the floating seal seat, floating seal ring, and rubber ring. Over time, this can extrude the rubber ring, and the contaminants can be repeatedly compressed and ultimately penetrate the seal.

Wear of the rubber ring

The rubber ring can easily be worn by impurities such as mud, leading to aging and tearing. The best solution is to choose a wear-resistant rubber material and provide a protective layer on the outside of the floating seal ring.

Considerations When Installing Floating Oil Seals

The correct installation of floating oil seals is crucial for their sealing performance. Therefore, pay attention to the following points during installation:

Thoroughly clean the cavity of the floating seal seat and all sealing components before installation. Remove any residual grease, dust, and other metal debris. Only take the sealing components out for use after cleaning to prevent surface wear.

After confirming that the rubber ring is close to the inner side of the metal ring, install half of the floating seal ring. Use specialized tools to push the floating oil seal into the seat hole, preventing positional deviation. Then check the position of the sealing components to ensure the rubber ring is parallel to the wall. Check the height of the sealing surface to the seat hole body surface at least at four points spaced 90° apart along the sealing circumference. The maximum height difference should be less than 1mm. If height adjustment is needed, do not push or pull the floating seal ring directly; use specialized tools to push or lift the rubber ring.

After confirming proper installation, first clean the metal surface with a clean cloth, then apply a layer of oil film to prevent dry friction between the sealing surfaces during the initial operation after installing the oil seal. Be careful not to apply oil to other areas, especially not the contact surface between the rubber ring and the floating seal ring.

Then install the other half, align the floating seal seats on both sides, and slowly and carefully assemble them, taking care to avoid impacting the sealing surface, which could damage the floating oil seal. The difference in the outer diameter of the paired floating seal rings should be less than 0.5mm.

If new parts are needed during installation, replace both halves completely with new ones. Do not mix new and old parts, even if the old sealing components are still in good condition.