ZF has announced a new modular rear axle concept to demonstrate how a modular system architecture can translates into ‘even greater customer benefits’. The Tier One supplier’s solution enables a vehicle with a twist beam axle or link SLA rear axle to be converted easily to a steerable rear axle concept with just a few modifications to the body.
Based on a non-driven basic axle the arrangment allows for an electric axle drive or a conventional rear axle drive, as well as the AKC rear axle steering, to be integrateddepending on OEM requirements. ZF states that this allows vehicle manufacturers flexibly on just one body variant.
“With the new rear axle system, we are offering our customers wide-rnging applications in disparate vehicle segments,” stated Uwe Coßmann, head of the ZF Car Chassis Technology division. “The solution can be used in hybrid, fuel cell, and battery-powered vehicles and can be combined with conventional all-wheel modules or with our active rear axle steering AKC.”
The basic axle entails a modular development of a Semi-Trailing Arm Rear Suspension (mSTARS). As part of this setup, the rear of the two outboard kinematics points of the lower control arm were replaced with an integral link and a toe link added. The toe link defines the track across the wheel hub and enables the toe-in to be adjusted precisely. As an alternative to a suspension strut, which tends to be used on semi-trailing link axles, the integral link in an extreme outboard position enables separate springs and dampers to be used. This solution tends to be cheaper and also provides more width between the wheel arches in the trunk.
The basic axle can also be combined with ZF’s AKC (Active Kinematics Control) rear axle steering. In this case, the rear wheels actively assist the front steering angle and the passenger car enjoys enhanced agility or stability, depending on the road speed, when changing direction. (Below)