Stenso - Hovedkatalog 2019

The space between the sealing lip and the shaft is very important. Sealing effect is achieved through pre/stressing of the sealing lip, in that the internal diameter of the sealing lip is chosen to be slightly smaller than the shaft diameter. The garter spring provides constant pressure that maintains radial pressure on the shaft thus the sealing edge is flattened to a certain width.A thin fluid film builds up under the flattened area. Its thickness (film) should be 1 to 3 um to avoid leakage.The lubricating film works as an interface between external air and the fluid. A fissure in this film of lubricant leads to leakage. Thus it can occur if the shaft causes cracks in sealng surface / area (see drawing) 2. Technical Data 2.1. Description of Rotary Shaft Seals 2.2 Functional Principle 299 Radial Lip Seal Outer Rubber Jacket Outer sealing surface Metallic Insert Garter spring Dust lip Spring groove Contact surface/groundside Contact surface/frontside Sealing edge Radial Spring Pressure Air Lubricating Film Fluid