3. Coupling properties

3.1 Homokinetism

A power transmission element is said to be homokinetic when it is a motion transmitter with β = α (figure 2 ), α and β being the angle of rotation of the driving and driven parts respectively.

This property is required when :

• angular information is important, for example when the coupling is inserted in a servo loop;

• the relative variations in angular positions and the dynamic effects induced are detrimental to the nominal operation of the system into which the coupling is inserted.