EV Startup Prepares to Enter Commercial Market with Novel EAxle
Harbinger’s all-electric medium-duty vehicle is currently undergoing a comprehensive set of proving ground tests.
Startup commercial electric vehicle manufacturer Harbinger is on a torrid work pace. Design, CAE simulation, supplier sourcing, test vehicle builds and other engineering tasks were completed in 2022 for its innovative medium-duty EV platform. For a company founded in mid-2021, it’s been an extremely nimble product development timeline.
“Things change on a constant basis and new information is incorporated almost immediately,” Phillip Weicker, chief technology officer of Los Angeles, California-based Harbinger Motors Inc., noted in an interview with SAE Media at the 2022 North American International Auto Show (NAIAS) in Detroit.
Weicker and other company co-founders, CEO John Harris and COO Will Eberts, have decades of experience across automotive, aerospace and battery technology industries, including at Boeing, Coda Automotive, Faraday Future, QuantumScape, Xos Trucks, and Canoo, a startup company slated to provide last-mile delivery EVs for Walmart in 2023. Their combined experience with EV programs and next-generation technologies provided the backbone for creating a new EV platform.
“Harbinger’s eAxle was developed internally by our experienced engineering team,” Weicker said, pointing out that primary components – including the permanent electric motor, gear train and housings – are Harbinger’s intellectual property domain. The eAxle’s pending patents address various aspects, including motor winding, lubrication, cooling, software and control strategies as well as the architecture.
“The electric motor and gear train are mounted separately from the axle with power transmitted to the wheels using articulated drive shafts, a first in the medium-duty commercial segment,” Weicker said. The power-dense motor is transversely mounted, which diminishes efficiency losses when compared to the efficiency losses associated with right-angle hypoid gearing, which is used in internal combustion engine (ICE) commercial vehicles and is a carryover to many EV trucks, according to Weicker.
Wheels are rigidly connected via a novel, single-piece forged axle with a full-floating wheel end to provide the payload capacity and flexibility of parabolic leaf springs. “With no prop shaft, the entire package is located in line with the rear axle and opens up the space in the vehicle frame to package the battery systems,” Weicker explained.
Harbinger’s Class 4 to Class 7 EV platform will use an 800-volt, liquid-cooled battery system that is scalable in 35-kWh increments. “By allowing customers to select the battery capacity that works best for them, we are able to offer them the most economical solution that meets their needs while maintaining the advantages of a common platform,” Weicker said.
Aluminum parts will be integral to the battery packs. “The recent availability of large format die-cast aluminum components gives us great flexibility in designing a cost-effective battery system that will withstand the rigorous environment in which we expect our vehicles to operate,” Weicker said. He noted that conventional multi-piece sheet metal construction techniques used for light-duty passenger vehicles would not meet Harbinger’s best-in-class lifetime targets.
With a step-in height below 28 in (711 mm), that best-in-class target meant overcoming numerous engineering challenges. To achieve desired ground clearance, breakover, approach and departure angles, an alternative to a traditional constant-section frame rail was needed.
“The use of an all-new fully forged steel crossmember over the rear axle, combined with variable section roll forming used to create our high-strength-steel frame rails, allows us to reduce the frame’s section height to accommodate the rear axle,” Weicker said. In the front, the use of forgings provides the ability to incorporate an industry-first medium-duty truck independent front suspension with the packaging requirements of a leaf spring and solid front steel axle.
Harbinger’s next step for medium-duty EVs involves various proving ground tests, including road gradients up to 32 degrees, full payload and trailer tow, winter-weather drives with low-friction surfaces (such as ice and snow) and hot-climate uphill grade towing. Powertrain and battery durability testing is also in the mix.
ElectroForge, a joint venture involving Harbinger Motors Inc. and Kalyani Powertrain Limited (a wholly owned subsidiary of Bharat Forge Ltd, India’s largest automotive forging company), will put the drivetrain on a course toward high-volume production. “The joint venture is our manufacturing and commercialization effort for the powertrain specifically,” said Harbinger’s CEO, John Harris. High-volume production is targeted to begin in late 2024 or early 2025 with low-volume production prior to that timeframe.