Reduction gearset
The reduction gear transfers the power output of the servomotor to the rack. The rotational ratio between servomotor and steering wheel is approx. 18.37:1 (13.37 with Integral Active Steering).
The reduction gear consists of a belt drive and a ball screw. The ball screw has a pitch of 9 mm per revolution (10 mm with Integral Active Steering). The servomotor drives the toothed belt. The belt drive has a reduction ratio of 2.85:1 (2.49:1 with Integral Active Steering). The toothed belt drives the ball screw. The ball screw has an internal ball return (5 rotations). The ball screw is noise-optimized.