The U.S. Department of Energy is betting $7 million on a research project to cut medium-duty truck fuel consumption by 50 percent. One solution could be a hybrid powertrain based on the first-generation Chevrolet Volt.
Automotive component supplier Robert Bosch LLC is leading a research and development team through the 39-month effort that began in 2016. It expects to have the hybrid powertrain operating in a vehicle in late 2019. So far, only simulations exist. But real parts are coming soon. And some of those are quite similar to what makes a Volt run.
“Our team asked, ‘Why can’t we use something like this but tailor it for the medium-duty segment?’ and that’s what we’ve done,” said Matt Thorington, a Bosch engineer in commercial vehicle electrification. He is the technical lead on the Medium-duty Urban Range Connected Extended Powertrain.
Commercial van builder Morgan Olson, suppliers VOSS Automotive and Ricardo, the University of Michigan and the National Renewable Energy Laboratory are working with Bosch.
“We’ve come up with a power-split transmission that uses two electric motors and operates full electric and also provides the flexibility for all other driving,” he said. “You couldn’t take the Chevy Volt and just add bigger motors and have it function the right way for commercial vehicles. But you could think about it in different ways and optimize it for that.
The Chevrolet Volt is a plug-in hybrid sedan that can travel about 53 miles on electricity before a gasoline engine kicks into power the vehicle an additional 367 miles.
Truck and bus makers are developing electric powertrains to replace gasoline and diesel engines when possible, as political and social pressures mount to reduce pollution from vehicles.
Many are focusing on the local delivery market, maintaining that trucks and vans with short daily routes fit best for electrification. Their batteries won’t need to be recharged until they are retired for the night.
A hydraulic hybrid powertrain for stop-and-go use, like garbage trucks, makes great sense, said Antti Lindstrom, IHS Markit medium and heavy truck analyst for North America. “With a hybrid, there is less concern about mileage.”
The powertrain Bosch is developing is “our own (intellectual property) so it’s definitely a variant. How we connect everything and how we control it is different. But in its base number of components, it is quite similar,” he said.
Small electric motors help make the planetary gear set work to best operate the motors and the combustion engine to get the right torque at the wheels.
“I think it helps to provide a single solution that can cover multiple areas,” Thorington said. “You have these last-mile all-electric fleets. You have the large Class 8 long-haul trucks. Maybe fuel cells are the answer there. Everything in between is a huge mix.”
Think dump trucks, delivery trucks, and flatbeds. If it is viable, the Medium-duty Urban Range Connected Extended Powertrain could help meet the Department of Energy’s goal of scaling and marketing what it funds. Thorington said the team is meeting with transmission makers.
“Bosch is not a transmission manufacturer. But we think with our system knowledge, our components and this IP that we’ve generated, we could work with a partner to bring this to market,” he said.
Lindstrom said Bosch’s leadership of the project lends credence to its prospects. He mentioned Allison Transmission Inc. or Eaton as possible partners.
“This is a high-interest focus for the industry.” Bosch has “the resources financially and the R&D capability.”