For a long time, involute gears have been
amongst the most important elements of drive
engineering. One of its essential applications is
the transmission of great forces and the reduction
and multiplication of rotations. In these processes,
the gears are often subjected to high stresses.
Errors on the flanks cause premature wear. This
leads to a shorter service time of the gears, a
poorer efficiency of load transmission and an
increase in the running noise. This is especially
critical as the gears are typical replacement parts.
Such parts which have been manufactured in
different production facilities and by different
production methods must later match with high
precision. In the manufacture of mass-produced
parts, such as gears for vehicles, it is, therefore, of
great importance to monitor the production
processes. This is normally done with the aid of
suitable gear measuring instruments which allow
manufacturing defects to be determined. The
results serve to evaluate the grade of the gear,
and they can also be used to correct the
manufacturing processes. Gear measurement is a
particular metrological challenge. The complex
geometry and the small manufacturing tolerances
require reliable and traceable measuring
processes.