Contacting Shaft Seal

Lip Seals

The cost-effective lip seal for small installation spaces, in radial and axial designs, above all for bearing units.

Function & Design

Sealing lip on the shaft

The radial shaft seal, also called a lip seal or rotary shaft seal, is the cost-effective standard solution for sealing rotating shafts. It is installed with an interference fit in a housing bore; the sealing effect is achieved by a spring-loaded sealing lip that presses against the surface of the rotating shaft. Because of the constant friction during operation, high demands are placed on the condition of the shaft surface. If the shaft is already worn, a shaft sleeve protects the running surface.

Cylindrical outer casing, static sealing in the housing Spring-loaded sealing lip, dynamic & static sealing at the shaft
Radial shaft seal (lip seal) with spring-loaded sealing lip
Applications

Where lip seals are used

Lip seals are preferred especially as a cost-effective solution in small installation spaces, with a wide range of applications, e.g. in motors, gearboxes, spindles, pumps, cement mills and compressors. The main field of application is bearing units, where the escape of lubricants is prevented.

Adequate lubrication of the seal is critical to its service life and reliability. The more thorough the lubrication, the lower the wear. The seal must never run dry. The medium to be sealed acts not only as a lubricant but also as a coolant that dissipates the frictional heat generated.

Lip seal
Lip seal
Carbon sealing ring
Sealing ring, split design
Sealing ring
Carbon sealing ring
Fields of Application

Technical Data

Material
PTFE, FKM, NBR
Operating temperature
−40…160 °C
Operating pressure
−0.9 to 500 bar
Circumferential speed
max. 40 m/s
Shaft diameter
20…600 mm
Downloads
Data sheet (DE) Data sheet (EN)
Frequently asked

Lip seals – briefly explained

What is a radial shaft seal (lip seal)?

A radial shaft seal, also called a lip seal or rotary shaft seal, seals a rotating shaft against the outside. It sits firmly in the housing; a spring-loaded sealing lip rests on the shaft and keeps lubricant or coolant inside the bearing. It is the most cost-effective shaft seal for small installation spaces.

What is the difference between a lip seal and a mechanical seal?

A lip seal seals via a lip sliding on the shaft and suits moderate pressures and temperatures. A mechanical seal seals via two flat rings running against each other and is designed for higher pressures, temperatures and demanding media.

Which materials are used for lip seals?

Depending on the medium and temperature, PTFE, FKM (fluoroelastomer) or NBR (nitrile rubber) are used. The material is matched to your application, from low temperatures up to 160 °C and pressures from −0.9 to 500 bar.

Up to which shaft diameter are lip seals available?

We supply lip seals for shaft diameters from 20 to 600 mm, as a standard part or as a precisely fitted custom solution. Further contacting solutions can be found under Shaft Seals.

Looking for a lip seal?

Get in touch. We develop individual, tailor-made solutions to meet your requirements.

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