Visitors are shown the two Digital Displacement motors which drive the rear wheels on this BMW, which is fitted with a hydraulic hybrid drive transmission, pictured in the drawing above.
Artemis replaced the standard transmission of a BMW 530i with a hydraulic one built around its efficient computer-controlled Digital Displacement hydraulic pumps and motors. As well as saving fuel by optimizing the engine speed, energy that would otherwise be lost when applying the brakes is captured and stored in a hydraulic accumulator about the size of a scuba diver’s air tank. The engine can actually be switched off and the car driven just from the stored energy, further decreasing its emissions.
Artemis’ Digital Displacement hydraulic hybrid is about one-third the size and weight of a similar electric hybrid transmission. And by being a series rather than parallel architecture, and by storing captured braking energy in a hydraulic accumulator instead of a battery, full power is available instantly, even with the engine off.
To power the vehicle, Artemis has fitted a Digital Displacement hydraulic pump and two Digital Displacement motors, one driving each rear wheel. The three machines are coordinated by a central transmission controller unit that also reads the driver’s pedal and controls the engine, taking information from a variety of sensors located around the car.
Each Digital Displacement unit has a controller located behind panels in the car’s trunk. The units peak at 97% efficiency, and Artemis claims that “the Digital Displacement technology ensures that they maintain higher efficiencies than any other hydraulic machine around.”
The car demonstrated in Edinburgh had a gasoline engine, and the Artemis technology can be used equally well with diesel and biofuel engines.
Commercial vehicles, rather than passenger cars, will most likely be the first on-highway vehicles to be fitted with the new transmissions. The Artemis Digital Displacement technology is built on hydraulic components for vehicles such as trucks and vans. Commercial vehicles make up almost 20% of road traffic in the UK, but contribute disproportionately to the country’s emissions because of their higher weight and high annual mileage. Artemis chose to work with a BMW because its engine is of similar power to medium size commercial vehicles.
Bosch Rexroth Corp. has purchased the worldwide rights to use the company’s Digital Displacement technology in on-highway vehicles. Another international manufacturer of hydraulic systems to the construction, agricultural and handling machinery industry has also signed up to use Artemis’ technology off-road.
As the project grows, Artemis plans to expand into the rapidly growing renewable energy sector. It has plans to replace wind turbine mechanical gearboxes with its hydraulic technology. Independent studies show that 30% of wind turbine downtime is due to mechanical gearbox failures. The increasing demand for wind turbines to be sited offshore is encouraging wind farm developers to look ever harder at gearbox reliability because maintenance costs are much higher offshore. Artemis has already begun developing the components for full size wind
turbines.
For more information, visit www.artemisip.com.
