The construction machinery and general mobile equipment industries require efficient rotary transmissions for hydraulic fluids. This applies in all cases where the use of hoses is not practicable for reasons of safety, function, or lack of space.

Parker took into consideration the compact design of these rotary transmissions and designed equally compact sealing elements which can be snapped into simple grooves.

There are two different types of Parker Prädifa rotary seals: For the stator with dynamic sealing on the inside, and for the rotor with dynamic sealing on the outside diameter of the seal.  Care must be taken to ensure that the high-pressure channels are placed towards the center, whilst the return, the low pressure, the control, and the leakage channels are placed towards the end (atmospheric side) of the rotor. This will ensure that the highly stressed high-pressure seals are lubricated and cooled from both sides and that no contamination may penetrate from outside. Due to the reciprocal pressure load, the back-up rings will also be sufficiently lubricated. As the end seals are subjected to low pressure only the problem of contamination and abrasion is here of less importance.

The Parker Praedifa rotor C5 seal was designed as an end-seal for low-pressure channels in rotors. In spite of the relatively simple design of this seal, a good sealing performance will be achieved. A back-up seal is not required.

Field of application:

Working pressure:                  ≤ 20 bar

Working temperature:         —30 to + 100 °C

Surface speed:                         ≤0,2 m/s

Mainly for use as an end-seal in all rotary trans-
missions  of  construction  machinery,  mobile
hydraulics and machine tool hydraulics, as well as for low-pressure swivel joints.

Installation:

These seals are designed to be snapped into closed grooves. To avoid damaging the seal, sharp edges within the installation area should be removed.

Compound:

The standard compound is an NBR-based elastomer with a hardness of approx. 84 Shore A.

For special requirements (pressure, tempera-
ture, speed etc.) please contact our Consultancy Service, so that suitable materials and/or designs can be recommended.