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Oerlikon Graziano showcasing 4-speed electric drive; up to 15% lower energy consumption

Transmission specialist Oerlikon Graziano is showcasing its 4-speed electric transmission, the 4SED (4 Speed Electric Drive). (Earlier post.) This new compact, lightweight transmission features increased efficiency, seamlessly smooth shifting and a scalable design, making it suitable for a wide range of vehicle types. A 4SED has been fitted to a Mercedes Vito minibus and wil be on show at Cenex LCV 2014, from 10-11 September.

4SED, based on Graziano’s original eDCT, uses two small electric motors instead of a single large unit. By providing four ratios, the motors run close to their peak efficiency for more of the time, and shifts are accomplished without interrupting the drive.

Overall energy consumption is reduced by up to 15% compared to a single-speed transmission, which translates into increased range or improved performance. The technology is scalable to suit a wide range of different vehicle types, urban electric cars, high performance cars, hybrid 4WD applications, electric city buses and trucks. It is suitable also for applications with 48V motors, allowing significant cost savings and reducing risks of high voltage.

4SED is truly innovative, it is seamless, it is clutch less and it needs no synchronizer. We intend to be a key partner developer/manufacturer of Zero Emissions Driveline Systems for all the OEMs playing in this increasingly relevant automotive sector.

—Paolo Mantelli, Oerlikon Graziano’s Head of Performance Automotive



Would a Tesla Model S85 do 345 miles instead of 300 miles with this 4x transmission and a Leaf 115 miles instead of 100 miles with a lighter version?

Secondly, could most EVs operate with much smaller, light e-motors, recover more braking energy and tow trailers and climb hills easier with a 4X transmission?


Hard to say how much a trans would do for extant EVs. If nothing else I'd guess you could measurably improve highway range with a higher gear. The Leaf could really use it. Probably wouldn't add 15% to the rated overall range, but the weight/cost trade against additional battery would be interesting to see.

Sounds like a broken record from me but making a transmission that will survive is as much a system issue as anything. The inertia of a high-speed rotor like the 14krpm Tesla machine can completely trash a gearbox. Shifting quickly during high acceleration will require integration with the motor control --- not at all impossible, but it has to be done right for the "seamlessness" Oerlikon touts without losing performance or blowing the thing up. As I understand it the Roadster was dogged by a manufacturing defect (though I would wager rotor control was also an issue), and Musk's heart is really hardened against transmissions. I think he should reconsider.

I've kept the old 4-speed trans in my Corvair EV conversion. (Someday it'll actually be on the road and not in pieces in the barn.) I do not plan on jammin' gears with it; actually I think 2nd and 4th are all I really need.

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