German Tier 1 supplier ZF is in the midst of reinvention as it transitions from being a manufacturer of hard parts such as transmission and chassis systems to one steeped in electronics and software.
Nothing characterizes this juncture better than the company’s first e-axle, aimed at truck applications from light-duty pickups to medium-duty commercial vehicles. The unit combines ZF’s long expertise in solid axles with its more recent moves into e-mobility.
The ZF eBeam Axle, demonstrated to journalists, analysts and customers at the supplier’s weeklong Next Generation Mobility Days event at the M1 Concourse private track in Pontiac, MI, is designed to be packaged into existing solid-axle vehicle platforms, meaning most automakers could transform their current internal-combustion-powered trucks into battery-electric vehicles with minimal effort.
The axle was shown off in a production Chevrolet Silverado 2500 pickup with 2-wheel drive, but its scalable design makes it a fit for vehicles up to Class 6 in size. A rear-drive configuration is featured in the demo vehicle, but ZF says 4-wheel drive also is possible.
The e-axle produces 300 kW (402 hp) of power and 7,376 lb.-ft. (10,200 Nm) of output torque in the Silverado application. ZF says outputs ranging from 180 kW (241 hp) to 350 kW (469 hp) are possible. Although it doesn’t have final numbers on towing capacity, the supplier expects the modified Silverado to exceed 10,000 lbs. (4,536 kg).
ZF uses off-the-shelf CATL battery packs in the Silverado demonstrator, which operates on an 800V electrical architecture and can be fully charged in about one hour using a DC fast charger. ZF says a 400V architecture also is possible.
Four batteries are positioned under the floor of the Silverado and two more are mounted in the truck’s bed, but those mainly are for testing purposes and not expected to be part of a production application. Each pack has capacity of 35 kWh for a total of 210 kWh.
The batteries add 551 lbs. (250 kg) in weight per pack for a total of 3,306 lbs. (1,500 kg). For comparison, the battery pack in General Motors’ GMC Hummer Pickup reportedly weighs 2,923 lbs. (1,326 kg).
In a ride around the M1 track, the propulsion system operates quietly and accelerates quickly enough, though the converted Silverado may not have quite the off-the-line jump of some of the electric pickups on or nearing the market. But this is a heavy-duty pickup, and ZF points out the e-axle is designed more for work than speed.
From the passenger’s seat, handling does not appear to be impacted too severely by the switch to electric power. You definitely can feel the extra weight at the back of the truck, but some of that drag presumably would disappear in a production vehicle that wasn’t carrying extra batteries around in the bed.
The axle itself is built mainly with off-the-shelf ZF components, including the motor, transmission and inverter that features silicon-carbide power modules. ZF would supply the complete unit to the truck manufacturer for installation on the final assembly line.
The supplier doesn’t provide any range estimates, noting it would depend on the application.
“Our focus was to build and integrate a highly efficient drive unit for a 3/4-ton pickup truck that gives the vehicle the same capabilities as its ICE counterpart,” says Jörg Trampler, program director-Electrified Powertrain Technology. “Our contribution to a good driving range is a drive system with high efficiency.
“Our first prototype already has a peak efficiency of 95%,” he adds. “We are not planning to go through all drive cycles required to determine the vehicle range; we leave that task to the vehicle manufacturer.”
Start of production is targeted for 2025-2026, though no firm contracts are in hand. In addition to retrofitting current pickups and commercial vehicles, ZF officials note the axle would work just fine in an all-new truck design.
The German supplier isn’t alone in pursuing e-axles. Magna, Allison Transmission, Dana and others have similar products in development or available, and the market is expected to grow significantly between now and 2025 and beyond.