Shaft Seals
Highest Quality Shaft Seals
Shaft Seals for Rotating Applications
Shaft seals (WDR) are central sealing elements in machines that prevent lubricants from escaping or contaminants from entering the system. They are used, for example, in housings, shafts, and push rods. The common designs are regulated in Germany by the DIN 3760 standard.
Radial shaft seals (RWDR) feature a sealing lip that runs on the rotating shaft. This is usually pressed radially against the shaft by an integrated garter spring. For optimal sealing performance and low wear, the shaft surface must be ground free of helix. Modern designs sometimes do not use a spring or utilize PTFE sealing lips.
RWDR are also used as fork seals in motorcycle forks. There they seal axially moving, usually chrome-plated stanchion tubes and ensure the function of the integrated damping system. The installation direction always depends on the pressure differential – the open side points towards the higher pressure area.
The result: reliable sealing solutions for rotating and oscillating applications – even under demanding conditions.
- Standard-compliant design according to DIN 3760
- With or without garter spring, also as PTFE membrane shaft seals
- Used, for example, in engines, gearboxes, pumps, fork systems
- Axial and radial sealing possible
- Also known as "Simmerring®" – a protected trademark of Freudenberg
PTFE shaft seals exhibit higher temperature resistance and significantly better chemical resistance compared to conventional elastomer shaft seals. The excellent dry-running properties of PTFE are also beneficial.
Frequently Asked Questions about Shaft Seals
What are shaft seals and what are they used for?
Shaft seals (also known as radial shaft seals) are sealing elements that prevent lubricants from leaking out and protect machines with rotating or oscillating shafts from dirt and moisture ingress. They are used in engines, gearboxes, pumps and other machine components to ensure reliable sealing between the rotating shaft and the housing.
How do shaft seals work?
In a shaft seal, the sealing lip lies radially against the surface of the rotating shaft. A garter spring is often integrated to press the sealing lip against the shaft and generate the required contact force. This keeps the lubricant inside the system while preventing contamination from entering.
Where are shaft seals typically used?
Shaft seals are used wherever rotating or oscillating parts need to be sealed. Common applications include engines, gearboxes, pumps and motorcycle forks, where they prevent oil loss and the ingress of dirt during suspension movement.
What is the difference between axial and radial shaft seals?
Radial shaft seals seal perpendicular to the axis of rotation—between the rotating shaft and the housing. They are the most common design for engines, pumps and gearboxes. Axial seals, on the other hand, act along the axis of the shaft and prevent leakage between two surfaces that slide against each other. The choice between radial and axial sealing depends on the installation location, the direction of movement of the components and the type of medium involved. In many cases, both variants are combined to ensure complete sealing.