Eaton Committed to Hybrid Drivetrains; Says Challenged by ‘Vertical Integration’

This story appears in the Sept. 3 print edition of Transport Topics.

Although natural gas has taken some of the limelight away from hybrid drivetrains for trucks, Tier One component supplier Eaton Corp. said it is still committed to electric and hydraulic hybrids, and announced a research plan to reduce the size of hybrid batteries by up to 50%.

Primarily known for its manual and automated manual transmissions, Cleveland-based Eaton is also fighting to maintain its appeal among fleets as some truck makers push “vertical integration,” encouraging buyers to specify in-house transmissions, John Coll, a vice president with the vehicle group, told Transport Topics editors and reporters on Aug. 28.

“The interest in hydraulic hybrids has dampened. We need to get a payback period for that of less than five years,” said Coll.

On the transmission side, though, he said Eaton has adapted its UltraShift Plus AMT for eight heavy-duty applications.

“We do transmissions, clutches and hybrids. All of our research and development goes there,” he said.

Refuse vehicles had been thought a promising market for hydraulic-hybrid drivetrains because of the heavy start-stop nature of their operations. Coll said, however, that many refuse fleets are switching to natural gas, which is mainly methane. Methane is a natural byproduct of landfill decay, and some landfills collect the gas and pump it into refuse trucks.

There are still good markets for diesel-electric hybrids, Coll said, mentioning city buses, pickup-and-delivery vehicles, the trucks in utility fleets and leasing companies. Some of these purchases are helped by government subsidies, particularly in California, he said.

The battery project will be done in Michigan and funded by Eaton and the U.S. Department of Energy.

The goal is to shrink the size of batteries in hybrid vehicles while maintaining capacity and performance.

Hybrid drivetrains capture energy from braking that is stored in a battery. The battery then helps move the vehicle from a standing stop, lessening the need for diesel.

Eaton and Allison Transmission are the two major independent suppliers of transmissions for North American heavy-duty trucks. Daimler Trucks makes transmissions for Freightliners and Western Stars under its Detroit brand. Volvo Trucks has a proprietary I-Shift model, and Mack Trucks calls its device mDrive.

Daimler and Volvo executives have said that to meet 2014 and 2017 federal standards for better mileage and lower greenhouse-gas emissions, it is critical to synchronize all aspects of the drivetrain within the truck.

Coll agreed and said this is not a matter of making “iron or gears” fit together tightly. It is more about software programming instead.

As an example, he said Eaton is making UltraShifts to work with natural gas-powered engines, and that means monitoring engine-transmission interac-

tions down to a thousandth of a second.

This can be done by an outside vendor, though, Coll said, citing an arrangement with Paccar Inc. as “virtual vertical integration.” Paccar offers Eaton transmissions in its Kenworth and Peterbilt trucks.

“We optimized our transmissions for Paccar’s MX engines, and it took us about two years,” he said.

Truck makers are the main customers for Eaton’s transmissions, but a lot of the company’s marketing efforts are done at the fleet level.

“It’s a push-pull situation. We push at the OEM level to sell our transmissions but also pull from fleets so they will specify our products,” he said.

As for other technologies the company is working on, Coll mentioned air supercharging as alternative to turbocharging or a complement to it.

While turbocharging uses exhaust gas to power a turbine to move air, supercharging uses the motion from the crankshaft to move air.

Cylinder shutdown and variable valve operations are other technologies that could be used to improve mileage, Coll said.