By Marek Krasuski
The transportation sector accounts for at least 70 percent of domestic petroleum consumption and nearly one third of our energy related carbon emissions. In the face of continent-wide initiatives to reduce our dependence on fossil fuels, the transportation sector has been working vigorously to transition to alternative and renewable sources of energy to drive our economy and the vehicles we so heavily rely on. Since 2008 there has been a significant increase in the introduction of hybrid electric and battery electric powered trucks and vans, mainly in the medium duty market consisting of delivery vans/trucks, service vehicles and utility trucks. Alternative powered vehicles today are migrating into heavy duty applications as well. And alternative powered drivetrains, involving a variety of power sources, are crucial to the successful integration of green vehicles in all applications.
Forward moving companies, like ALTe Alternative Energy Company, has been a global supplier of electric powertrain systems for medium duty applications such as delivery trucks and vans and buses. (Powertrains include all drivetrain components plus the engine.) Significant fuel reductions are promised by the company. For example, a delivery truck with ALTe’s hybrid electric prototype, based on a Ford E-350 chassis, has been completed and originally had 7 mpg. With the hybrid electric powertrain the same vehicles reach 18 mpg.
Hybrid and electric powertrains, though still lagging behind their diesel and gasoline counterparts, are poised for expansion thanks in part to government incentives. Another company specializing in hybrid propulsion powertrains for the medium duty and heavy work truck sector is Odyne. The system offers the greatest benefit for trucks with driving cycles that have a high percentage of starting and stopping and extended periods of work site engine idle time to provide power to equipment or tools. The system easily integrates with medium- or heavy-duty vehicle powertrains and is applicable across chassis manufacturers. The company says their system is capable of supporting 6 – 18kW of exportable power, versus 3kW on many other hybrid systems.
Efficient Drivetrains Inc., (EDI) is another player in the competitive heavy duty Electric Vehicle (EV) market which specializes in plug-in hybrid (PHEV) and EV retrofits. A supplier of electrification kits for class 6 & 7 trucks, the company will soon introduce the PowerDrive 8000, a kit for Class 8 vehicles which adds to the lineup of the PowerDrive 6000 and PowerDrive 7000 kits for class 6 & 7 trucks. It will be available in electric and plug-in hybrid options. Notes EDI, the PowerDrive Kit “offers OEMs a modular design for easy integration into existing chassis designs and enables rapid vehicle solution introductions. Electrification kits will include a high-efficiency drivetrain (EDI PowerDrive™), vehicle control and telematics software (EDI PowerSuite™), and the training and support infrastructure to enable fast time to market. To speed market introductions, EDI can also install the powertrain systems and perform vehicle integration as a service for OEMs.” In addition, the company says the PHEV version uses less fuel than other hybrid options available. The PowerDrive kit is popular in large part because of its modular design that easily integrates into existing chassis. The EV offers a range of 100+ miles and the plug-in hybrid a 35 mile range.
Dana has been a long time provider of customized drivetrains tailored to the unique demands of each vehicle. Its Spicer line of transmissions, axles, driveshafts and hydraulic-hybrid solutions has well served the needs of the heavy duty truck market in construction, logging, mining, and material handling applications. Construction drivetrain systems offer advanced technologies for multiple vehicles ranging from 3 to 50 tonnes. These include wheel loaders, telehandlers, wheeled excavators, single drum rollers and motor graders. Drivetrain systems for telehandlers allow for tighter turning radius in confined environments and are equipped with hydrostatic powershift transmissions that deliver power necessary to move more material per hour. Dana’s Spicer drivetrain systems for wheeled excavators include hydrostatic transmissions which provide enhanced fuel efficiency, smoother shifting and improved operator comfort for maximized productivity.
Dana also offers driving systems for mining machines ranging from loaders, trucks, drills, excavators and load haul dumpers. Drivetrains are configured to handle the most rugged underground environments. For example, components for load haul dumpers handle bucket lift capacities from 3 to 5 tonnes. Drivetrain systems – transmissions, axles, brakes, and driveshafts – cover the full range of payload capacities from 15 to 50 tonnes, and drivetrains for mining drill carriers handle curb weights from 15 to 70 tonnes.
Most transmissions today are still manual, having withstood the test of time, but they are giving way to automated manual transmissions (AMT) and automatic alternatives. Until recently automatic and automated transmissions, integral components to drivetrains were limited to on-road applications as they were unable to withstand the grinding pressures of off road use. That changed with the introduction of Eaton’s Ultra Shift Plus automated manual transmission. According to the company, it has “automated the gearboxes vocational customers have come to trust. This allows them to maintain the gear ratios they are already accustomed to while enjoying all the benefits of automation. We’ve taken our highly robust manual box and automated it, so it has the exact same ratio coverage with an UltraShift PLUS that you have had from your Eaton manual transmission.” Eaton UltraShift PLUS transmissions are available for a full range of vocational applications, including dump trucks and mixers. The company has also automated its 18-speed transmission for heavy-haul applications.
An overall driver shortage in the industry, coupled with the diminishing number of top drivers able to expertly shift gears in manuals, has made AMTs and fully automatics more appealing for fleets that must face the realities of attracting drivers from a declining labour pool. And in tricky environments such as back roads drivers handing automated and automatic trucks remain more alert as they are unencumbered by the divided attention that results from constant shifting and worrying about achieving optimal gear ratios.
AMTs (automated manual transmissions) and fully automatic transmissions are not the same thing. In the automatic transmission market, Allison Transmissions dominates. In vocational applications where trucks are subject to frequent stops and starts, automatic transmissions provide uninterrupted power to the wheels when ramping up through the gears. This helps cushion shocks to the driveline. In mining and construction applications, for example, Allison fully automatic transmissions have been shown to achieve faster work cycles and extended service intervals.
AMTs by contrast are manual transmissions that automate the operation of the clutch. Electronic sensors, processors and actuators do the shifting to match travel speed with the load and job application. AMTs, though, do provide key benefits. Automatic transmissions, by contrast, are far pricier than their AMT counterparts, and technicians familiar with manuals should find working on an AMT easier than an automatic.
Another dominant player which has been providing driveline parts and components for over 100 years is Meritor. The company was the first in North America to provide permanently lubricated drivelines for life in the heavy duty commercial market with the RLP Series. The benefits are reduced operating and maintenance costs, and extended U-joint life, especially on gear-fast/run-slow drivetrains and higher torque applications. Other benefits include a 5-year/500,000-mile linehaul warranty, and high-torque-rated models available for demanding applications, including heavy service and downspeeding; four-bolt design for easy installation and service; and E-coated steel guards which secure and protect the slip seal against contaminants and damage. Most recently, Meritor launched an authorized Rebuilder Program for Axle Carriers to cover the Canadian market. Noted Krishna Natarajan, Senior Director, Steering, Suspension and Drivetrain, Aftermarket for Meritor, “Our authorized rebuilders are committed to using 100 percent genuine Meritor content for replacement parts and approved processes to deliver the highest-quality rebuilt carriers that fleets expect.”
To be sure, expect to see even more intelligence baked into drivetrains for both the on-road and off-road markets. Regulations calling for greater efficiencies and the reduction of emissions produce tangible benefits and savings for users.
For more articles related to drivelines, download our latest issue and read the “Fleet Maintenance & Management” and “GPS/Telematics Management” columns.☚