AxleTech Develops Electric Independent Suspension Concept for Vehicles Up to 58,000-lb GCWR

August 1, 2018

Ryan Gehm

The 5000 Series eISAS concept developed by AxleTech consists of a standard independent suspension axle, a custom-designed motor, and proprietary helical gearing design that maximizes regenerative braking. (Image: AXLETECH)

Intended for a range of vehicle types — full battery electric vehicles, fuel cell range-extender EVs, and internal combustion engine or turbine generator range extenders — the 5000 Series electric independent suspension axle system (eISAS) recently revealed by AxleTech serves as a complete electric powertrain. As such, the next-generation concept can eliminate the need for a traditional drivetrain, including engine, transmission, and gearboxes — the result being reduced weight and maintenance costs, according to the Troy, Mich.-based technology company.

“We have spent the last two years developing our line of electric powertrain systems for on- and off-highway vehicles,” Bob Nichols, Senior Manager, Sales, Electric Vehicle Systems at AxleTech, told Truck & Off-Highway Engineering. “The eISAS concept is a result of our ongoing efforts to lead the electrification of drivetrain and powertrain systems, while commonizing our axle product families.”

In developing the 5000 Series eISAS concept, engineers considered the modernization of military fleets and the enhanced performance such vehicles require. Nichols noted the system can offer improved stealth characteristics, lower heat signatures, and improved fuel savings to logistics vehicles, tactical vehicles, and armored personnel carriers.

AxleTech is partnering with TM4 on the motor and inverter development. Shown is TM4’s CO300 inverter for heavy-duty vehicles. (Image: TM4)

“As with any new product development program, there are many challenges and hurdles, and we address everything through a systems-engineering approach,” he said. “The team worked on providing a system that addresses optimal efficiency and packaging while taking into consideration the vehicle’s requirements and duty cycles.”

The concept consists of a standard independent suspension axle, a custom-designed motor or motors (depending on the vehicle application), and proprietary helical gearing design suitable for electric powertrain systems that maximizes regenerative braking. The complete eISAS would also include one or more inverters, depending on the application.

AxleTech partnered with TM4 on the motor and inverter development, and tapped its global supply chain, “which includes new and current suppliers,” for the system concept, Nichols said.

When produced, the eISAS concept axle will feature parallel axis gearing, instead of traditional bevel gearing, to maintain the axle ground clearance and allow for maximum torque to the wheels. All Nichols would offer when asked to provide more details on the proprietary gearing was, “It’s an optimized strategy that comes from our systems-engineering approach.”

The 5000 Series eISAS concept is intended for vehicles with a gross combination weight rating (GCWR) up to 58,000 lb (26.3 metric ton) capacity. AxleTech intends to develop similar propulsion concepts for lighter load vehicles as part of its overall electrification strategy. The timeline for production of these eISAS concepts will be driven by customer demand, Nichols said.

“All AxleTech electric axle product offerings are engineered for both commercial and military applications. We are developing solutions for on- and off-highway applications, such as buses, trucks, heavy lift trucks, and others,” he said.

The company has supplied independent suspension systems to the military for more than 25 years and has over 60 fielded vehicle programs for its ISAS products.