Semi Rigid Axles
The semi-rigid axles used today in many FWD vehicles as rear axle represents a special version of compound axles.
All semi-rigid axles are characterized by a very simple design and therefore very cost-efficient production.
→Based on design, one distinguishes between Torsion Crank Axle (flex arm suspension), Twist Beam Rear Axle (semi-independent suspension) and Twist Beam Rear Axle (semi-independent suspension) with rearward displaced cross member.
→The Torsion Crank Axle (flex arm suspension) is the oldest design, see figure.
Similar to a rigid axle, the two wheel carriers are firmly linked to each other by means of a bending-resistant but torsionally weak section.
→Longitudinal axle control is effected via longitudinal links welded to the cross member, which also functions as a stabilizer.
→Transverse axle control is effected by a Panhard rod, which can also run diagonally underneath the vehicle floor if this provides a more favorable mounting point for force application on the body.
→The positions of the longitudinal centers are determined by the positions of the mounting points of the longitudinal links on the body. The position of the roll center depends on the location of the Panhard rod.