World’s first fully active suspension with energy recovery system announced
October 1, 2013
ZF Friedrichshafen AG has entered into partnership with Levant Power Corp. based in Woburn, Massachusetts, USA, to build the world’s first fully active suspension system with energy recovery function. GenShock-technology is a fully active system for passenger cars which will combine dynamics, safety and comfort characteristics with minimum energy consumption and energy recovery.
The recently agreed cooperation paves the way for revolutionary damper technology, “We are looking forward to working closely together with Levant Power. The objective is to develop the world’s first fully active and regenerative suspension, make it ready for volume production, and introduce it to the market. Thus, we are promoting efficient innovations that are tailored to meet global requirements”, stated Rolf Heinz Rüger, in charge of the Suspension Technology business unit of ZF’s Car Chassis Technology division. “Ride and handling are at the core of the driving experience. With GenShock-technology, ZF and Levant will reinvent that experience,” added Shakeel Avadhany, Founder & CEO of Levant Power.
Car makers have long sought a suspension that offers sport cars handling while maintaining comfort of a premium luxury saloon. The difficulty in achieving this outcome rests in balancing comfort and handling; comfort requires a soft suspension to absorb bumps, while handling requires stiffness for control. Previous attempts to achieve high-bandwidth active suspension have fallen short due to cost, complexity, and power consumption.
A unit fitted to the outside of the ZF damper forms the technological basis of the active regenerative system. The valve technology, states ZF, has been developed specifically for this application. The very compact unit is composed of its own control unit, an electric motor and an electrohydraulic gear pump. Driven by an electronically controlled electric motor, the gear pump regulates the oil flow in the damper. “For dynamics, comfort, and safety, it is essential that active forces can be applied into the chassis”, explains Rüger. For this reason, the damping characteristic curve does not only adapt optimally to each driving situation automatically; but also bodywork pitch motions during abrupt braking manoeuvres and rolling motions during rapid evasion manoeuvres are virtually eliminated. Moreover, the technology is capable of actively raising each individual wheel.
As soon as the driving situation permits, the new valve system automatically uses the swaying motion of the damper piston to recover energy. The system guides the oil in the damper in such a way that it drives the electric pump motor. This then functions like a generator, converting the kinetic energy generated into electricity, and feeds it into the vehicle power supply, thus contributing to a reduction in CO2 emissions. This effect is most powerful when the vehicle is traveling on poor-quality country roads.