The loader is now in production and, according to John Chesterman, Deere’s global product manager for four-wheel drive loaders, is of interest to “users with high hour shift work, and those in environmentally sensitive areas.”
A diesel-electrical combination powers the hybrid, which uses a power shift torque converter and has 50-percent reduced noise levels (2 decibels lower inside the cab and 3 decibels lower outside the cab) compared to the conventional model.
The hybrid has the same bucket size, dump height, operating weight and net peak horsepower as the conventional 644K, while the engine has changed from a 9-liter to a 6.8-liter Deere PowerTech 6068.
“[The engine] runs at a constant speed, with a max of 1,800 rpms,” Chesterman said. “With the conventional, we need a lot of engine torque, up to 2,250 rpms, to respond to loads.”
Chesterman added that the hybrid is expected to deliver fuel consumption reduction by 35 percent in truck loading operations, 16 percent in stockpiling operations, 10 percent in transport operations and 24 percent in idle.
