On a fully electric car, as Tesla, they use a standard transmission? Or there is something inherent to electric motors that need a different technology?
I mean: electric motors can rotate at very high speeds. Do it even need a gearset? Or can it just rotate from 0 RPM to say, 15k RPM? Or there is a torque curve or efficiency issues involved?
Sort of. Unlike gas motors which get part of their mechanical advantage from the angular momentum of the flywheel, electric motors have a torque that is strictly proportional to the current through the coils.
AC motors (like the ones Tesla use), work by pushing a sinusoidal wave around the "outside" of the stator, while a similar sinusoidal wave (at a retarded phase) is run inside the stator. This creates a magnetic field which is "ahead" of the stator's field (well in forward mode) which "pulls" it toward the field. The torque curve is "constant" and the speed is limited only by how well you can modulate that voltage. (and of course the mechanical construction)
The torque curve of an electric motor is linear with speed inversely. Tesla never changes gears. There is a fixed reducer between the motor and the wheels.
I mean: electric motors can rotate at very high speeds. Do it even need a gearset? Or can it just rotate from 0 RPM to say, 15k RPM? Or there is a torque curve or efficiency issues involved?