1. Preliminary

Technical validation involves the choice of friction material or bearing type. This makes it possible to fine-tune friction coefficients, predict service life and maintenance frequencies, define the characteristics of the shaft and any accessories such as oil pump, filter, protective seals, etc., and finally to accurately calculate the relative cost of the various solutions.

In this respect, it's important to consider all the elements involved in the overall cost, and not just the friction part, bearing or silent-block. The following costs should not be overlooked:

• material, any processing and machining finishing of shaft and housing ;

• any protective seals ;

• lubrication system ;

then beyond the way we think they...