Reinventing the Wheel... to include a motor with no unsprung weight penalty

摘要

Electric motors are round. Wheels are round. It's a pretty natural impulse to combine the two. No lesser automotive luminary than Dr. Ferdinand Porsche did it first, inventing the wheel-hub motor in 1897. He mounted two of them to his front-driven battery-electric prototype "Lohner-Porsche." Three years later he invented the gas-electric hybrid by fitting four hub motors to his elaborate four-ton "Mixte" coach. The one tiny rub: Those 14-hp motors weighed around 320 pounds. Each.Modern materials and engineering have enabled dramatic improvements. For about seven years, Protean Electric has been selling a 100-hp hub motor that weighs just 68 pounds. So why do all volume-produced EVs still mount their motors inboard? To minimize unsprung weight for optimal ride quality.