August 29, 2008
Caterpillar introduces the D7E â€” the first electric drive track-type tractor using modern technology. The revolutionary electric drive system developed for track-type tractors gives the D7E an optimum balance of power, efficiency, control and maneuverability. The system delivers higher productivity, reduced fuel consumption, reduced operating costs and longer drive train component life compared to other tractors in its size class.
The D7E is in the 60,000-pound (27 000-kilogram) weight range and is powered by a Cat® C9 engine producing 235 horsepower (175 kilowatts). Compared to the Caterpillar® D7R Series II, the D7E will deliver 25 percent more material moved per gallon of fuel, 10 percent greater productivity and 10 percent lower lifetime operating costs.
Caterpillar plans to commercially introduce the D7E in select markets during 2009.
In the D7E power train, the diesel engine drives a generator to produce electricity that ultimately powers two AC electric drive motors, which are connected to a differential steering system. A traditional mechanical transmission is not needed, because the variable speed electric motors serve the function of a continuously variable transmission. The electric drive train has 60 percent fewer moving parts compared to previous D7s. The electric system also provides power to auxiliary components so that no engine belts are needed.
In addition to the electric drive system, the D7E incorporates many design improvements. Most noticeable to an operator is the industry exclusive center post cab. The cab provides more all-around visibility and wider sight lines to the blade for better operator productivity and enhanced jobsite safety.
Other D7E features and benefits include:
Additional information about the D7E will be announced in 2009 when the electric drive tractor nears commercial availability.