Caterpillar introduces the D7E ” 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:
- Electric drive train makes operator training easier, because there are no gears to shift.
- A spacious tilt cab provides a comfortable environment and allows ready access for maintenance. The electric air conditioning system is a self contained module and is mounted outside the cab. Noise levels in the cab also are reduced by 50 percent.
- A single, larger blade lift cylinder replaces the traditional dual cylinders. It provides the power and stability of a dual-cylinder system but with less than half the parts ” for reduced maintenance. It also aligns with the center post of the cab to enable enhanced visibility.
- The C9 engine with ACERT® Technology meets U.S. Tier 3 emissions standards, and the tractor has been designed with Tier 4a in mind.
- The available SystemOneTM undercarriage reduces undercarriage operating costs by 35 to 70 percent.
- Optional AccuGradeTM grade control system can cut job costs significantly. Every D7E will come Grade Control Ready, which allows installation of the AccuGrade Attachment Ready Option at the factory or at the dealer.
Additional information about the D7E will be announced in 2009 when the electric drive tractor nears commercial availability.