Type ADP Oil Seal

Type ADP Oil Seal Supplier UK

Type ADP Oil Seal or Hydrodynamic lips are generally regarded as lip refinements designed to improve sealing at the top limits of shaft speed, heat, vibration or shaft eccentricity. Where plain lip performance has given only marginally satisfactory results, it is worth considering the use of shaft seal with this “positive action feature”.

The hydrodynamic feature is generally moulded into the rear face of the sealing lip or “Air Side”. It can take several forms as favored by leading oil seal manufacturers, some of which are patented designs. The most common are moulded helixes, but care must be taken when using these as they are “uni-directional” and if used for the wrong direction of rotation can actually encourage leakage. The safest designs are therefore the “bi-directional” features. These appear as moulded ribs, waves, double helixes and triangular pads – all claim to assist in pumping lubricant or other sealed fluids from under the lip back into the machine or sump. During the development of these features
care to avoid “over-pumping” action, which may have led not only to the entry of the oil film but also to any other fluid or foreign matter present, must have been considered. The various designs of Hydrodynamic or Positive action
lips have now been in evidence for over 35 years in some form or another and are widely available as standard in metric sizes, plus a limited range of inch sizes, in both Nitrile and Viton material.

In exactly the same way as a plain lip seal. Lubricate both the O.D. and I.D. lip with clean oil or the sealed fluid and install as previously described with the garter spring facing towards the bearings (into the oil). There is an increasing use of ribbed or semi-ribbed rubber O.D. seals – these are not hydrodynamic features but seal retainers, particularly useful where aluminium housings are used or high thermal expansion may be a problem.

The most common seal of this type is the Spiroseal, available in the full standard metric range in Nitrile and Viton material. It has a plain rubber O.D., metal insert, and single sprung lip.

For more information on our range of Type ADP Oil Seal or Hydrodynamic lips seals, download the catalogue or contact a member of the team.