1. Technical problems

The technical situation (figure 1 a ) is as follows: a driving shaft S ₁ , linked to the frame or housing S ₀ by a pivot connection of axis Δ ₁₀ , is to drive a driven shaft S ₂ itself linked to S ₀ by a pivot connection of axis Δ ₂₀ . We are in the simple situation where Δ ₁₀ and Δ ₂₀ are concurrent, i.e. contained in the break plane, but not aligned by a break angle α.