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Gearing EVs for greater efficiency

  • Magazine Article
  • 21AUTP02_01
Published February 01, 2021 by SAE International in United States
Language:
  • English

Ingear, an innovative 2-speed transmission born in Canada, aims to unlock electric-vehicle performance and efficiency.

A long-touted benefit of electric vehicles (EVs) has been the utter simplicity of their drivetrains. With just a pair of reduction gears between the traction motor and final drive, single-speed gearing helps to minimize the bill of material (BoM) and driveline-system cost while delivering acceptable performance.

But the more demanding duty cycles of commercial EVs, off-road equipment and high-performance passenger EVs are prompting development of multi-speed solutions. Tesla got there first, albeit unsuccessfully, in 2007. While still a start-up staffed mainly by electronics engineers, Tesla developed its own 2-speed gearset for use in its Roadster sports car. Perhaps not surprisingly, catastrophic failures of early production units led Elon Musk to reluctantly commission a clean-sheet single-speed unit designed by Ricardo and manufactured by BorgWarner.