Sealing of Pressurised Media in Automotive Applications for Rotating Shafts

The rubber industry provides special oil seals from elastomeric materials to seal pressurised shaft applications. Normally these are small and simple looking devices, which can tolerate quite complex conditions.

The design of the seal has a tremendous impact on good performance. Basic parameters for pressure oil seals made from elastomeric materials will presented. Application conditions must be balanced to the degree of seal stress. For example the right compromise has to be chosen for flexibility and stability of the lip section. The heat which is generated by friction must be dissipated through the shaft and the medium to be sealed. Medium and elastomeric material must not be overloaded thermally.

The product of pressure and surface speed (p · v) is an important characteristic for the evaluation of how much a seal is stressed. A graph of achievable ‘p · v’-figures will be presented.

In general pressure applications require closer attention to material selection than general purpose seals.

Pressure oil seals for automotive applications will be presented with examples for power steering, hydraulic drive units and a tire inflation system.