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Dan Dorsch with his clutchless hybrid transmission for high-performance cars. His college projects have led to a number of inventions, including an underwater biomimetic burrowing device known as the RoboClam, for anchoring autonomous underwater vehicles.(Lemelson-MIT Program photo)

Clutchless hybrid transmission concept for high-performance cars

An MIT student-inventor’s clutchless hybrid transmission concept aims to provide high-performance vehicles an energy-saving attitude without compromise.

The concept mechanism uses an electric motor to fill the acceleration lag that occurs when a driver releases the throttle and engages the clutch. A second electric motor is used for quickly speed-matching the gears during the shift since there is no mechanical means to speed up the next gear before engaging it.

“Right now, we are only at the proof of concept stage," Dan Dorsch told Automotive Engineering. "There is quite a bit of work left in order to develop the transmission into something that can be used on a production car.”

Dorsch, 26, is a second-year Ph.D candidate and a National Science Foundation Graduate Research Fellow in the mechanical engineering program at the Massachusetts Institute of Technology. His invention earned him $15,000 as the 2016 Lemelson-MIT “Drive it!” Graduate Student Prize winner. The competition is funded by Portland, OR-based The Lemelson Foundation and administered by MIT’s School of Engineering.

Many current high performance production cars rely on a dual-clutch transmission, including those with a hybrid-electric powertrain. Two current examples are the plug-in hybrid Porsche 918 Spyder with a 7-speed PDK dual clutch transmission, and the hybrid Ferrari LaFerrari with a 7-speed dual clutch automated manual.

Innovations that can maintain or improve vehicle performance and increase fuel economy quickly attract the attention of the industry's engineering management. According to Devin Lindsay, IHS Automotive’s Principal Analyst for North America Forecast, “Even high performance cars are not immune to fuel economy regulations.”

Weight reduction was one of Dorsch’s design bogies.

“The lightweight aspect is due to removing the double clutch, including the fluid that often fills the clutches,” he said. “And since high performance cars often have one to two motors for performance reasons, we can use the motor or motors in the powertrain to replace the function of the clutch.”

Dorsch’s MIT research advisor and two student teams assisted with the project’s development. Two concept prototype architectures were built, each lasting about four months from design to hardware. The MathWorks' MATLAB models show how the transmission is likely to perform.

“We have also analyzed different driving scenarios based on a specific powertrain configuration,” said Dorsch.

Transitioning the concept transmission to a testing phase is likely to unfold with a European high-performance vehicle OEM that he would not identify. Said Dorsch, “It’s possible that lab testing on a prototype concept transmission with this OEM could happen as early as 2017.”

Dorsch has filed a patent application on one of his transmission designs. He said the provisional patent describes the overall architecture, its functionality, and the driving modes.

A patent application will be filed in the coming months for the second design. “This design uses a single electric motor whereas the patent-pending design uses two electric motors,” he said.

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