|The Peterbilt 386 Class 8 hybrid.|
Hybrid technologies developed jointly by Peterbilt Motors Company and Eaton Corporation have been integrated into an aerodynamically styled Class-8 heavy-duty vehicle.
Wal-Mart Stores, Inc., which operates the nation’s second largest private fleet, is supporting development of the technologies by helping to validate the concept and refine the final design.
|Eaton’s Heavy-Duty Hybrid System. Click to enlarge.|
The Eaton heavy-duty hybrid system with idle reduction features an automated manual transmission with a parallel-type direct hybrid system, incorporating a 44 kW electric motor/generator located between the output of an automated clutch and the input to Eaton’s Fuller UltraShift transmission.
The system captures energy generated by the diesel engine and recovers energy normally lost during braking and stores the energy in batteries. That electric torque is then sent through the motor/generator and blended with engine torque to improve vehicle performance, operate the engine in a more fuel-efficient range for a given speed and/or operate only with electric power in certain situations.
The system’s batteries power the heating, air conditioning and vehicle electrical systems while the engine is off. When the idle reduction mode is active, engine operation is limited to battery charging, an automatically controlled process that takes approximately five minutes per hour to fully charge the system. In the proposed system design, a proprietary feature minimizes engine vibration during start-up and shutdown during the recharge periods, allowing the driver to rest without interruption.
During third-party testing, the Eaton Hybrid Power System has routinely achieved a 5-7% fuel savings versus comparable, non-hybrid models. It may result in a savings of one gallon of fuel per hour when idling.
Peterbilt and Eaton have previously partnered to develop hybrid electric Class 6-7 vehicle platforms and Class 8 hybrid hydraulic vehicles. With a successful test and evaluation program, the heavy-duty hybrid electric power system will be available in 2009.