Dana Holding Corp. introduced the new Spicer AdvanTEK Dual Range Disconnect concept for tandem axles used in Class 8 linehaul applications. Optimized for trucks that implement engine downspeeding, this breakthrough tandem axle technology improves efficiency without sacrificing performance by seamlessly combining the traction and dependability offered by a 6×4 configuration with the reduced drivetrain losses and improved fuel economy of a 6×2 configuration.
The concept employs a single gear mesh configuration from the engine to the wheels and can enable improved overall powertrain system efficiency from 2 to 5% when compared with conventional 40k tandem axles paired with overdrive transmissions commonly used today, the company said.
At startup, on grades, at low speeds, during backup maneuvering, or in other environments where additional traction is needed, the technology allows the tandem axle to operate as a 6×4 with a traditional starting ratio that delivers the optimal tractive effort needed. At low speeds, this ratio offers improved performance over fast-ratio 6×4 tandem axles by enhancing maneuverability while reducing the likelihood of high torque spikes.
As the truck nears highway speed, an electronic control unit (ECU) in the axle coordinates with engine and transmission ECUs to disconnect the inter-axle shaft from the power divider, allowing the axle to operate in a more efficient 6×2 mode. At the same time, it shifts the forward axle to a faster ratio that enables the engine speed to decrease to as low as 900 rpm for highway cruise operation.
By using separate axle ratios for low- and high-speed operation, this technology also enables linehaul trucks to accelerate from low velocity to highway cruise speed much quicker than a 6×4 or 6×2 tandem axle with a single, fast ratio. The technology improves fuel economy by reducing drivetrain losses in the inter-axle power divider, inter-axle shaft, and rear drive axle gearing; enhances net engine efficiency by better complementing engine torque curves; and lowers overall powertrain system weights.
In addition to these performance benefits, concept enables the use of fewer gears in the transmission and avoids the need for larger engine mounts and frame rails while improving launchability, gradeability, driveability, and low-speed maneuverability.
“New fuel economy regulations for linehaul trucks are on the immediate horizon, and truck manufacturers are already addressing the challenge of reducing fuel consumption beyond the levels that can be achieved through today’s conventional powertrain systems,” said Mark Wallace, executive vice president of Dana and group president of Dana On-Highway Driveline Technologies. “Our advanced Spicer AdvanTEK Dual Range Disconnect concept enables truck manufacturers to achieve substantial gains in fuel economy with a system that still performs dependably in adverse driving conditions.”
For more information, visit www.dana.com.
