Turcon® rotary shaft seals are characterized in particular by their low-friction and stick-slip-free running, which reduces heat development and permits higher peripheral speeds.

Turcon® has the characteristic of inherent memory, whereby a distorted Turcon® component will attempt to recover the profile it had during the sintering cycle of its manufacturing process. This feature is used to provide the necessary radial loading of the sealing lip onto the shaft, therefore negating the requirement for the energizing spring present in elastomeric seal designs.

Where required, seals can employ hydrodynamic sealing, which, in conjunction with the mechanical retention of the Turcon® in the seal body, gives exceptional seal performance.

Turcon® rotary shaft seals from Trelleborg Sealing Solutions are available in two product ranges: Varilip® and Varilip® PDR.

Varilip®

Six different types (A-F) of Varilip® seal are available in a range of sizes suitable for DIN/ISO standard housing and groove sizes. Varilip® seals use a plain lip and can thus be used on shafts that rotate in either direction.

Type A - is a single lip seal suitable for use in standard industrial applications up to a pressure of 72psi where an elastomer radial shaft seal would be unable to withstand the temperature, friction, medium or poor lubrication. Allows sealing at surface speeds up to 100ft/s with sufficient cooling and lubrication of the sealing lip.

Type B - is the preferred choice for applications in which a high seal integrity is demanded or where contaminated media is to be sealed. This type offers a back-up sealing lip to provide greater safety than the Type A.

Type C - can be used for applications involving higher pressures for which a simple elastomer radial shaft seal can no longer be considered. Due to reinforcement of the sealing lip, pressures up to 290psi are possible, e.g. as pump, shaft or rotor seals.

Type D - can be subjected to pressure from both sides. Pressure differential of up to 14psi is permissible. The separation of two different media using a single seal is possible. The second lip can also take on the function of a wiper or dust lip.

Types E- is similar to Type B but has an additional lip to prevent contaminants from reaching the sealing lips. This enables an effective solution in environments where the seal may be exposed to abrasive particles.

Types F- is similar to Type C but has an additional lip to prevent contaminants from reaching the sealing lips. This enables an effective solution in environments where the seal may be exposed to abrasive particles.

Varilip® PDR

These seals are individually designed to satisfy the demands of specific applications and can therefore accommodate non-standard housing and shaft sizes. Typically they consist of a pressed or machined casing and a mechanically retained Turcon® element. In many applications they do not require the use of a gasket, thus improving the chemical resistance of the seal system.

Where required, Varilip® PDR seals can employ a hydrodynamic feature on the Turcon® sealing lip. This provides a positive displacement of the fluid as a result of the shaft rotation to give improved sealing in applications where the shaft only rotates in a single direction. The feature also increases the flexibility of the lip which allows a wider contact band between the TurconR lip and the shaft and helps to reduce shaft load and associated wear.

Varilip® PDR seals are produced as one of three basic design styles: 'clamped', 'crimped' and 'single shell.' Axially split housings or housings with a poor surface finish or enlarged tolerance can be accommodated with the use of a rubber OD cover or O-Ring.

Varilip® PDR's relatively simple design and the nature of the machined or pressed casings promote the potential for integration of the seal into the surrounding hardware. Furthermore, the mechanical retention of the Turcon® provides a robust product which also eliminates the sometimes environmentally hazardous process of bonding the Turcon® to a metal or elastomer substrate.