Oil Seal Rotary Shaft Seal R21 is a single lipped rubber coated seal with a metal inner.
Available in Nitrile, Viton and Silicone.
Oil Seal Rotary Shaft Seals R21 also known as lip seals, are used to seal rotary elements, such as a shaft or rotating bore. Common examples include hydraulic pump seals, axle seals and power steering seals. Early rotary shaft seals used leather as the sealing element. Modern elastomers replaced leather, industry also added a garter spring which helps the sealing lip compensate for lip wear.
The seal construction will consist of a sprung main sealing lip which has a point contact with the shaft. The point contact is formed by two angles, with the air side angle usually less than the oil side angle. Depending on the seal type these two angles are varied to create pressure distribution at the seal contact point which has a steeper slope on the oil side of the seal. The shallower the slope on the oil side of the seal the wetter the seal will run. The spring is positioned such that axially the centerline of the spring is biased to the air side of the lip contact point.
In order to exclude contaminants dust lips lips may be used. In order to resist wear, the compounds’ durometer (hardness) is typically 70 to 85 Shore A.