EXECUTIVES from Eaton Corp announced during a June press conference that the company has begun development of a hybrid electric power system for the heavy-duty (Class 8) commercial vehicle market — to deliver both on-road efficiency and idle reduction for significant fuel savings and emissions reductions.
The heavy-duty system will be similar in design and will share many of the same components as Eaton's medium-duty hybrid electric system built for Class 4-7 vehicles, but will be adapted for Class 8 vehicles used for on-highway applications. The company expects to have approximately 300 hybrid vehicles on the road by 2007.
“We see an exciting future for hybrid electric vehicles in the heavy-duty market place,” said Kevin Beaty, manager of Eaton Hybrid Power Systems. “We've demonstrated our leadership in hybrid power over the past five years for our medium-duty customers, and we're confident that we can carry that forward with a strong value proposition to our heavy-duty customers.”
Beaty indicated that the heavy-duty hybrid power system is in the testing and development phases, and that Eaton is working with truck and engine makers and select fleets to develop prototypes for field evaluation. Eaton's heavy-duty hybrid power system is expected to be available well before 2010, and could help meet the next round of Environmental Protection Agency (EPA) engine emissions regulations.
Fuel savings
Fleets using Eaton's heavy-duty hybrid system will experience reduced fuel consumption both while driving and when parked. Recent independent test results have shown a 5% to 7% savings versus a conventional Class 8 vehicle while driving, and a savings of one gallon per hour when parked. Those savings equate to about $9,500 a truck per year in normal operation, resulting in cost savings of $9.5 million per year for a typical truckload carrier with 1,000 power units.
The idle reduction mode in Eaton's heavy-duty hybrid system will enable fleets to save fuel, reduce emissions, and comply with rapidly expanding local anti-idling laws. The system's batteries power the heating, air conditioning, and vehicle electrical systems while the engine is off. When the idle reduction mode is active, engine operation is limited to battery charging, an automatically controlled process that will take approximately five minutes per hour. In the proposed system design, a proprietary feature minimizes engine vibration during start-up and shutdown during the recharge periods.
Eaton's heavy-duty hybrid electric power system will be built using an automated manual transmission with a parallel-type “direct” hybrid system, incorporating an electric motor/generator located between the output of an automated clutch and the input to a Fuller UltraShift transmission. One feature of this system will be its ability to recover energy normally lost during braking and store the energy in batteries. The hybrid drive system adds about 500 pounds to vehicle weight.
Exhaust treatment
Also looking to the future, Eaton executives discussed work being done on innovative technologies for diesel exhaust aftertreatment. Vishal Singh, marketing and business development manager for new technologies at Eaton's Truck business unit, said that Eaton's aftertreatment system will be ready to meet the strictest diesel emissions requirements in the world — the 2010 EPA regulations. Eaton's system uses a combination of fuel reformer catalyst with doser, selective catalytic reduction catalyst (SCR), and lean NOx trap (LNT).
“We have proposed a novel aftertreatment system that combines a fuel dosing unit, fuel reformer catalyst, a LNT catalyst, and a SCR catalyst in series to scrub NOx from the system. While most SCR systems being proposed today use urea as a means of carrying the ammonia needed to catalyze the NOx, Eaton's system generates its own on-board ammonia. The result is a cost-effective system that meets EPA requirements and eliminates the need for urea distribution and infrastructure or on-board urea tanks.”
The fuel reformer generates an optimal mixture of reformate gases to improve LNT regeneration efficiency. During “lean” exhaust conditions, the LNT stores NOx. During rich exhaust conditions (LNT regeneration), the LNT converts stored NOx to nitrogen and produces ammonia. This ammonia is stored by the downstream SCR catalyst and is used to convert remaining NOx that slips past the LNT. NOx reduction takes place in two stages once by the LNT and second time by the SCR catalyst.
New UltraShift model
Turning to the present, Eaton added the Fuller UltraShift LEP (Linehaul Efficient Performance) to the UltraShift family of automated transmissions. The LEP is in a limited quantity release phase, with full-volume production scheduled for the first half of 2007. Roadranger marketing is working with all of the North American truck makers to place the UltraShift LEP in their 2007 data-books for optimum availability.
The UltraShift LEP was designed with optimized shift calibrations to keep engine RPMs low and in the best “fuel-island” while maintaining performance and drivability. Created to work in select engine families, this optimized shift calibration is obtained by computer-controlled shifts within a relatively tight window of close steps unique to that family. These shifts enable the LEP transmission to stay within the engine's fuel map contour for maximum efficiency and performance.
The LEP features 13 forward speeds and three reverse ratios with overall ratio coverage of 14.25:1. Specifically designed for on-highway use in any terrain, the UltraShift LEP offers torque capacity coverage up to 1,750 pounds per foot (in the top two gears) and an 80,000 gross combined weight at cruise speeds up to 65 miles per hour. Eaton is working with truck and engine makers to tune the UltraShift LEP specifically to each engine.
Key features and benefits of the UltraShift LEP transmission include:
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Two torque capacities, both approved to 80,000 lb. GCW: 1,650 lb/ft and a 1,650 “M” (Multi-Torque) model with 1,750 lb-ft operation in top two gears.
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Automatic starts, utilizing Eaton's AutoClutch module, based on the industry standard 15 ½-inch twin plate, ceramic-facing technology.
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Electronic shift protection and totally automated operation reduces the potential for drivetrain abuse.
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Reduction of part counts and improved serviceability by utilizing the same electronics, controls, and XY shifter as Eaton's other Gen3 UltraShift products.
Dana axles
Dana Corporation's Commercial Vehicle also rolled out additions and improvements to its axle products that are marketed under the Roadranger brand name as part of an alliance with Eaton's Truck Components group. Announcements covered new drive-axle ratios, a gear lubrication improvement, and a new LMS hub system for use with wide-based tires.
Dana's Torsionally Tuned-40 (DST40) tandem-drive axle is available with new 2.64:1 and 2.93:1 ratios, and the S170 single drive axle offers a 2.53:1 axle ratio. These ratios will be particularly effective in improving fuel efficiency for fleets running lower engine RPMs at cruising speed with direct-drive transmissions and low-profile tires.
“These new axle ratios significantly improve drivetrain efficiency, which is key in optimizing fuel consumption,” said Leo Wenstrup, senior product manager of drive axles for Dana. “Fleets that specify Dana's Spicer DST40 or S170 drive axles will quickly realize the benefits of lowered cost of operation and improved fuel efficiency when engine cruise speed is optimized.”
Wenstrup also touted a technological development that promises to improve the overall efficiency of its Spicer drive axle lineup by better controlling the flow of lubrication. Called a lube director, the technology will be incorporated in 2007-model-year drive axles. Based on field and lab testing, the lube director is expected to reduce the negative effects of energy-consuming gear churning by as much as 20%.
Dana officials also announced immediate availability of the new Spicer LMS wide-based hub system for drive and trailer axles, meeting the needs of customers that require a long-life, low maintenance wheel end that is designed to maintain load ratings with wide-based tire applications. The new hub system is compatible with standard-track axle configurations.
The LMS wide-based hub system is available on Dana's Spicer 23,000-lb and 40,000-lb drive axles and P-spindle 71.5-inch and 77.5-inch track trailer axles, and is approved for use with two-inch offset wheels. The new LMS hubs meet the growing customer demand for interchangeability and application flexibility between wide-based tires and standard dual tires, reducing downtime and supporting future resale value in the marketplace.