September 24, 2007 8:30 AM, EDT

E&MU: Eaton, Truck Makers Ready Medium Hybrid for 2008

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Hybrid drivetrains, combining diesel and electric power and developed by Eaton Corp., will be available in 2008 on medium-duty truck chassis made by Freightliner Corp., International Truck and Engine Corp. and Paccar’s DAF, Kenworth Truck Co. and Peterbilt Motors Co., according to several announcements by the manufacturers involved.

Paccar also said it has signed an exclusive agreement with Eaton to get hybrid technology ready for Kenworth and Peterbilt heavy trucks by 2009.

Peterbilt recently announced delivery of its first mediums — two Model 335 hybrids — to McCoy’s Building Supply in San Antonio. The Model 330 is powered by the Paccar PX-6 diesel engine, which is rated at 240 horsepower and 560 foot-pounds of torque. Engaging the hybrid system boost the rating to 300 hp and the torque to 860 foot-pounds.

Peterbilt also said it is working with Eaton and Wal-Mart Stores’ corporate fleet to evaluate a Model 386 hybrid-electric for longhaul applications.

In testing so far, the Model 386 hybrid has produced a 5% to 7% fuel savings over conventionally powered trucks of comparable size, Peterbilt said.

On the medium side, Eaton has produced some 220 hybrid-power systems for evaluation, placing most of them into service on package vans, medium-size delivery vehicles, utility service trucks, beverage haulers and city buses.

The Eaton medium system going into production has an electric motor and generator situated between the output of an automated clutch and the transmission input. Main engine operation regenerates storage batteries, which also capture and hold energy normally dissipated during braking.

Blending electric torque with engine torque in this “parallel” system helps the vehicle accelerate from a dead stop. Peterbilt calls the feature “Launch Assist.”

Also, the power from the lithium-ion batteries can be channeled into a power takeoff for stationary activity. The diesel engine periodically turns on to recharge the batteries, which Peterbilt said takes less than five minutes.

The system is based on Eaton’s Fuller automated transmission, which each chassis manufacturer will use with its own engines, James Sweetnam, president of Eaton’s Truck Group, said in August. It will not be available with a standard transmission.

Kevin Beatty, Eaton’s manager of hybrid power systems said the company plans to ramp up production over the next three years to meet anticipated demand.

Eaton also is working on hydraulic propulsion that would replace the conventional drivetrain and transmission. A hydraulic pump and motors and hydraulic storage tanks recover and store energy, similar to what is done with electric motors and batteries in hybrid electric vehicles.