Hydraulic braking could generate $500m market

US researchers say they have developed a technique for recovering energy normally lost during vehicle braking, and converting it to hydraulic power that can be harnessed to accelerate the vehicle. The development, being done jointly by Ford and the Eaton Corporation, could improve fuel consumption by 25-35% and generate a market worth $500m by the end of the decade.

The technology, called Hydraulic Launch Assist (HLA), was unveiled at last month`s Detroit Motor Show where it was shown on a Ford Mighty F-350 Tonka concept truck (above). Energy recovered from the vehicle`s brakes is held in a fluid form in an on-board reservoir until the driver next accelerates. It is then used to augment the vehicle`s engine to produce what Eaton calls a "brisk" acceleration.

The two main components are a reversible hydraulic motor/pump which is coupled to the drive shaft through a clutch system, and an energy storage module containing accumulators filled with hydraulic fluid and nitrogen gas at a pressure of up to 3.45 Mpa (500 psi). Easton and Ford reckon that they can recover and use up to 80% of the initial kinetic energy.

The development is part of a larger project to develop hydraulic drive systems with the backing of the US Environmental Protection Agency. Eaton Chairman Alexander Cutler says that the "unique, potentially game-changing" programme could have a significant impact on "two critical areas of long-term concern": fuel economy and exhaust emissions.

He adds that Eaton has already invested millions of dollars in the HLA technology which could be ready for commercialisation by the middle of the decade.