Saving Energy in Start-and-Stop Vehicles

TwinTorq motor mounted in Hyster® chassis.

New Motor Design Could Cut Energy Use in Forklifts, Garbage Trucks, Buses

Funding from Oregon BEST is helping an Oregon startup collaborate with researchers at Oregon Tech and one of the world's largest forklift manufacturers to build a combination electric-hydraulic motor that could extend driving range by as much as 40 percent between charges for electric vehicles that start and stop frequently, like garbage trucks, forklifts, buses and delivery trucks.

TwinTorqTM, the technology developed by KersTech Vehicle Systems of Portland, Ore., marries two existing and proven technologies – electric motors and hydraulic motors – in a single compact design to regenerate energy during frequent braking, then use hydraulic power for launch acceleration at low speeds when electric motors are not as efficient. Depending on vehicle speed the new system regenerates energy either hydraulically or electrically. The vehicle automatically switches between hydraulic and electric when hydraulic energy is depleted.

"Combining electric and hydraulic motors in a single, compact motor that shares components has never been done before," said Lester Erlston, CEO of KersTech. "Since hydraulic systems are three times more efficient for regenerative braking and reusing energy at lower speeds, combining the sweet spots of both motor types offers much higher overall efficiency."

The Oregon BEST funding is enabling KersTech to partner with Professor James Long and other faculty and students at Oregon Tech to create the mechanical components and software needed to integrate the TwinTorq motor into a 3-ton Hyster® forklift manufactured by NACCO Materials Handling Group, Inc. (NMHG). NMHG will test the performance of the prototype motor at its research and test facility in Fairview, Ore.

“We believe the TwinTorq motor system has the potential to provide our customers with longer run-time and lower energy consumption, and we look forward to testing these outcomes in collaboration with the team at KersTech,” said a spokesperson for NMHG.

Current electric forklifts have a battery range of only about five hours, far less than a full 8-hour work shift, Erlston said. The TwinTorq technology could increase battery range to eight hours or more.

Long and the Oregon Tech team will refine the control algorithm that switches the TwinTorq motor between hydraulic and electric, and will perform CNC manufacturing of many parts of the prototype motor.

"This is a great opportunity for our students to work on a real-world application that could reduce energy consumption in an innovative way," said Long.

Oregon BEST was instrumental in bringing the parties together for this multi-player project, said Ken Vaughn, Director of Commercialization Programs at Oregon BEST.

"This is a terrific example of an Oregon startup teaming with an established Oregon company and university researchers to develop a technology that has the potential to save energy and create jobs," Vaughn said. "If the initial testing is successful, this same technology could be applied to larger vehicles like buses, garbage trucks, and parcel trucks."

Erlston said the Oregon BEST funding comes at an ideal time for the company.

"This funding is enabling us to have a prototype built and to work with a company the size of NMHG, who wouldn't have come on board as a collaborator to help with testing had it not been for the Oregon BEST funding," said Erlston. "It's also a big plus to have Oregon Tech involved in the project, because their third party engineering expertise helps validate our technology."

Grants and other support for the project have come from Drive Oregon and OTREC, in addition to the in-kind contribution by NMHG. Additional testing will be done at Linn-Benton Community College in Albany, Ore.

SOURCES: Ken Vaughn, Oregon BEST, 503-725-9801; Lester Erlston, CEO, KersTech Vehicle Systems, 503-524-2404; James Long, Professor, Oregon Tech, 541-885-1580

About KersTech Vehicle Systems http://www.kerstech.com
KersTech Vehicle Systems is an Oregon developer and manufacturer of high efficiency drivetrain systems, with granted and pending patents for technologies that conserve energy in electric and hybrid vehicles.

About NACCO Materials Handling Group, Inc. http://www.nmhg.com
NACCO Materials Handling Group (NMHG) designs, engineers, manufactures, sells and services a comprehensive line of lift trucks and aftermarket parts marketed globally primarily under the Hyster® and Yale® brand names. NMHG is a wholly owned subsidiary of Hyster-Yale Materials Handling, Inc. (NYSE:HY). Hyster-Yale Materials Handling, Inc. and its subsidiaries, headquartered in Cleveland, Ohio, employ approximately 5,100 people worldwide.