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VIDEO: Contact seals 101

Everything you need to know about contact seals

The basic principle of a seal is clear; keep the good things in and the bad things out. But how exactly they do that, alongside avoiding excessive wear and overheating, maintaining a constant radial load, and compensating for misalignment – that takes a little more explanation. Watch the video and read this article for a short but sweet introduction to contact seals

It’s no secret that smooth-running systems rely on the quality of their components, as well, of course, on the way that these components are maintained. Contact seals’ (often referred to as radial shaft seals or oil seals) importance is sometimes overlooked. But in fact, their dependability and lifespan can make a huge difference to system performance and make or break productivity.

Point of contact

Their primary role is to separate media, demonstrated in the video by the lubrication being isolated to guard a bearing in a rotating shaft. They also have to be effective against external contamination, including air, wastewater, dust, or aggressive media like steam. High-pressure water is another contaminant – and we have said it before on Industrial Seals Expert; using high-pressure water to clean equipment can cause more damage than good!

Seals in a spin

Contact seals, as they are constantly exposed to rotating parts, are subject to generating high friction and therefore high temperatures. A small contact surface, as well as the use of an SKF WAVE lip, reduce the amount and vary the location of the contact, thus bringing down temperatures to bearable levels. The pumping effect instigates hydrodynamic oil circulation, keeping temperatures lower and managing the oil film.
Complicating matters is the need to retain the radial load, a problem offset using a garter spring. With their ability to withstand forces from all directions, the spring is a key component to maintaining the seal’s effectiveness. As a machine vibrates or shifts due to high speed or malfunctions elsewhere, the garter spring compensates for the misalignment and ensures the seals remain tight.

Watch the video!

Proper sealing is a priority for a high-performing system, so there is every reason to be clear on how to ensure your sealing solution is the right one.
Have a look at the video for a visual representation of how things function – and a brief glance at how seals from SKF look in action.