Trucks: Eaton’s HEV vocational hybrid truck technology

Dana unveiled several new products at a recent press conference at the company’s Kalamazoo, Michigan, vehicle test center. Most of them – including Dana’s Eaton Ultrashift transmission variants – are designed for long-haul freight applications. But there was notable vocational product news too.

Most interesting to vocational truck owners was a prototype of Eaton’s HEV vocational hybrid truck technology. The prototype in question is an International 4000 Series utility truck outfitted with an array of specialized components that allow it to use electric power in low-rpm settings or to power the manlift on the rear of the truck. In addition to the usual truck components like a diesel engine, transmission and battery, this truck is also fitted with an electric motor/generator, motor controller/inverter, hybrid control module, energy storage system and applicable software to make up a hybrid powertrain. Using regenerative braking, the on-board generator creates and stores electrical power. The hybrid control system monitors vehicle performance, and switches back and forth between diesel and electric power as necessary.

I drove the prototype truck on Dana’s test track at the Kalamazoo testing facility and can report the system works almost seamlessly. At low speeds – under 25 mph or so – the truck is running solely on electrical power. The diesel engine is on, but idling. Step on the gas, and the truck moves forward normally. But keep your eyes on the tachometer, and you’ll note the indicator stays rock-steady at 1,700 rpms, even as the truck gains speed. Even weirder, the diesel remains at a quiet idle – there’s no increase in engine noise to match the acceleration – until you reach 30 mph or so, when the hybrid control module switches over to diesel power and the engine suddenly wakes up.

Because the hybrid powertrain captures a large amount of energy through regenerative braking and kinetic friction, the system makes a lot of sense for utility trucks and perhaps (eventually) dumps and mixers. Eaton’s initial tests show the International 4000’s HEV energy storage system can easily power the manlift for up to nine hours in normal working conditions, with the diesel engine off.

Currently, Eaton is producing 20 advanced, pre-production Class 7 trucks in partnership with International Truck & Engine for national deployment and assessment. Although the hybrid prototype truck is a success, Eaton warns many obstacles remain before commercially viable models can be made available to the general public.

Still, Eaton has shown the technology has strong potential in certain vocational applications and can be easily integrated into fleets with little or no adjustment on the part of drivers and owners. To that end, the company is building multiple partnerships with government agencies, truck OEMs and engine manufacturers to further explore vocational hybrid technology.

New vocational steer
axles rated up to 22,800 pounds

Dana also introduced its new D-series steer axles at Kalamazoo. Currently, they’re being offered in two configurations: the D-2000F model gross axle weight rating of 20,000 pounds and the 22,800-pound-rated D2200F. These heavy-duty axles are engineered for heavy-haul vocational applications and are compatible with either air-disc or drum-style brakes. “D-Series axles feature tight turning angles for construction applications,” says Mark Davis, steer axle product manager.

“And giving you the choice of disc or drum brakes allows you to better tailor a truck for your specific applications. At the same time, the D2200F axle’s 22,800-pound rating allows for greater payloads or larger tires for more flotation – all of which add up to a lot more productivity for your fleet.”