Скачать или смотреть Do electric cars need a gearbox?

Do they? Yes! But it is much simpler than the one in a petrol car. Why? The answer lies in torque and inertia. This is what I learnt from building my own electric cars, condensed into a short video with animations for you:

In a petrol car you need to match the gear to the speed, too high a gear and you stall, too low a gear and you can't reach high speeds. The problem is the low torque of the motor.

You could build a big motor that always has enough torque, but it is much cheaper and pragmatic to combine a smaller motor with a manual or an automatic transmission.

A petrol car will have a reduction from 2:1 to 14:1 depending on the gear to correct for the little torque. An electric car only needs one gear, and 8:1 appears to be a magic number.

The electric cars I built are driving 80mph in reverse: we removed one of the cogs and the motor is constantly spinning in reverse.