Why don’t electric motors need transmissions?
Unlike your typical ICE, electric motors have a much larger RPM range. They make their best power output over an incredibly broad RPM range, so you don’t need the extra gears to constantly keep it in the happy zone. By contrast, ICE only generates usable torque and power in a narrow band of engine speeds and therefore need more gears to keep it running in its power band.
Thanks for the explanation. I think I get it now.
Great explanation. It doesn't mean that electric motors can't use transmissions (Porsche Taycan uses a two-speed)...they can certainly use transmissions but there's really no point.
Here's what the output of a combustion engine looks like
The aim of the transmission is to keep the engine rotation within that green "power band" (~2,000 - 4,000 RPM in this case, but it could be higher)
This is the output of an electric motor. It has maximum torque (motor is happy) all the way up to ~8,000 RPM.
Whoa. Thanks for sharing the graphs. Makes everything easily understandable.