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2008 Con-Expo-Con/Agg: Showtime

May 03, 2008 |

The numbers were quite frankly above everyone’s expectations: more than 144,600 attendees, and 2.28 million net square feet of exhibits taken by 2,182 exhibitors – all in all a show that was 21 percent bigger than the last ConExpo-Con/Agg, held in 2005. Contractors seemed to take the media’s dire economic news with a grain of salt and showed up in droves. They were rewarded with an electrified atmosphere, a solid look at just-around-the-corner technology, plus the skinny on products already in production.

Up to 20 percent less fuel use with electric-drive D7E
Cat’s D7E boasts the first dozer-specific electric drive and an industry-exclusive single post cab. With more than 100 patents, the D7E is “innovative from the inside out,” says David Nicoll, Cat’s commercial manager for track-type tractors. The net effect for users, according to the company:

10 percent more material moved per hour
25 percent more material moved per gallon of fuel
Up to 20 percent less fuel consumption

How does the D7E electric drive work? 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. And cables have replaced the hard drive shaft.

By comparison, in the D7R – which the D7E will eventually replace – engine power goes through a torque divider and a powershift transmission.

Cat says the electric drive – with its sealed, liquid-cooled components – works in all environments. Eliminated are what the company calls “nuisance items”: engine belts, alternators and electric water pumps.

All potential line-of-sight barriers such as the exhaust, precleaner, single lift cylinder and an optional center-mounted AccuGrade post now line up with the cab center post, creating 35 percent more visibility in the cab.