Tips to Protect Bearings From the Elements
The utmost significance of safeguarding bearings from dust and water ingresses cannot be emphasized enough. This article aims to provide valuable tips and methods to protect bearings and explore suitable shaft seal designs for contaminated conditions, ensuring early-life destruction prevention.
Machine Environment - Special attention is required in dusty and wet surroundings. Particles and moisture accumulate at the bottom of the bearing, leading to emulsification with the oil. This causes the element to rub against the surface, ultimately resulting in race or roller failure.
Bearing Housings - Selecting the appropriate shaft seal and seal configuration is crucial for bearing longevity. Dusty environments typically utilize labyrinth or contact type rubbing seals, allowing some shaft flexing. When installing a lip seal, ensure the sealing lip faces outward to prevent dust ingress.
- Lip and Labyrinth Seals - While the lip seal is commonly used for sealing the shaft to the housing cap, it is not the most satisfactory sealing device. Over time, the rubber material in the lip deteriorates due to various catalysts, necessitating routine replacement. The labyrinth seal, when used with grease flush, performs better for shaft sealing.
For both labyrinth and lip shaft seals, employing an automatic lubricator enhances bearing life. In high dust contamination scenarios, redesigning the shaft seal arrangement may be necessary to improve dust protection beyond standard housings. Ideas for reducing dust ingress include parallel seal configurations, spring-loaded shaft-wiping devices, stuffing boxes, and packing at the housing interface, among others.
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Assembly - Assembling bearings into housings should be carried out with utmost cleanliness, ensuring a spotlessly clean environment. Steps to ensure cleanliness include clean hands, a dust-free atmosphere, a clean workbench, and avoiding grinding or sweeping nearby during assembly.
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Breathers - Breathers release hot air from confined spaces and allow air to return when the space cools. A poorly screened and filtered breather can permit dust and moisture ingress, causing premature bearing failure. Protect breathers or filters from water spray and dampness using a shroud or an extension tube leading to a clean environment. Inadequate breathers should be replaced with low-micron air filters that remove dust particles of two microns and larger.
In conclusion, ensuring proper protection against dust and water ingresses is vital for maintaining bearing integrity and prolonging their service life. Employing appropriate seals, assembly practices, and breathers in various environments can significantly enhance the reliability and performance of bearings in industrial applications.
