|The Argosy Hybrid. Click to enlarge.|
Innovative Transport Solutions Pty. Ltd., an Australian startup that developed a retrofit plug-in hybrid electric conversion system for heavy-duty vehicles (earlier post), has entered into an alliance with Australia’s Cooperative Research Centre for Forestry (CRC for Forestry) and TimberCorp to produce a purpose-built 6x6 electric hybrid prototype retrofit and an electric hybrid road-train prime mover (truck/tractor) for the Australian forestry industry.
The prototype Argosy Hybrid will be shown at the Sydney Truck Show, 7-9 August 2008. The truck will be in service for preliminary trials on a Sydney-Melbourne route (about 1,900 km (1,200 miles) round-trip) soon after the show. Expected reduction in fuel consumption and emissions output is 25%.
The Argosy hybrid is based on a 07/2006 model Freightliner Argosy 101 Prime Mover Sleeper Cab, equipped with an Eaton Fuller 18 speed Auto change transmission and Cummins 6-cylinder 550 hp turbodiesel.
The conversion replaces the trailing, non-drive rear differential/axle with a duplicate front differential/axle. The output shaft of the replacement is connected to the electric motor/generator. A combination of ultracapacitors and a lithium-ion battery (supplier still to be determined) mounted between the chassis rails in front of the turntable store the electricity for the motor/generator. The electric motor is liquid cooled, with a suitable cooling unit fitted to the chassis.
Proposed modes of operation for the hybrid trucks include:
Truck leaves terminal with fully charged batteries via the electricity grid.
Acceleration using combination diesel and electric assistance.
Highway cruising using diesel only and cruise control.
Hill climbing with cruise control engaging electric assistance to maintain road speed. Diesel rpms and throttle position remain static.
Down hill, regenerative braking slows the vehicle and recharges the batteries. Diesel engine rpms remain low, no over revving. Braking also recharges batteries and saves brake wear.
Quiet mode, electric assist is engaged to maintain road speed while diesel engine only idles. This is for travelling slowly through towns and cities to reduce noise pollution.
There is a severe shortage of used 6x6 truck tractors in Australia. One aspect of the purpose-built ITS solution for the timber industry—which CRC for Forestry is quite interested in—is the simple conversion of 6x4 prime movers into 6x6 drive. The timber industry requires the more robust drive to move trailers around the work areas with their very poor road quality. CRC for Forestry is also interested in cutting the fuel consumption of the line haul trucks, which haul semi-trailer and road trains with gross vehicle weights of up to 90,000 kg (198,416 lbs) an typically operate 40-50% of the time empty with an average fuel consumption of 60-80 L/100km (2.9-3.9 mpg US).
|Another approach to converting a 6x4 tractor to a 6x6 with hybrid electric drive. Click to enlarge.|
ITS is also developing a different approach to converting a 6x4 drive to a 6x6: the replacement of the front non-drive axle with an electric-drive steer axle. A PTO-driven alternator supplies power to drive the new front axle and recharges the on-board electric storage system. (See diagram at right.)
ITS is working on a number of other conversions, including some for light-duty vehicles, and is developing a conversion for a new truck for a US client, due to debut early in 2009.