US Patent 8226101 Torsion system for torsion axle/suspension

A torsion system (20) comprising a housing (24) adapted to be secured to a structural portion of a vehicle. A shaft (23) has a core portion (32) accommodated in the housing (24) and defines concavities (34) in the core portion (32). The shaft (23) has a connector end (30) connected to a crank arm. The connector end (30) protrudes out of the housing (24). Elastomeric members (25,25′) are received in the concavities (34) of the shaft (23). The elastomeric members (25,25′) each have a geometry so as to at least partially fill the concavities (34) and contact an inner surface of the housing (24), whereby a rotation of the crank arm results in a deformation of the elastomeric members (25,25′).