That’s how diesel-electric locomotives work. Also giant dumptrucks at strip mines etc. It’s not unproven technology, but a neighborhood mechanic won’t usually have the knowledge; you’d have to go to a railroad maintenance facility.
> diesel-electric locomotives
Yes, I know. That’s been around maybe 70-80 years.
Not especially relevant to pickemup trucks.
And they work well. The reason for that configuration is as ICE engines scale up, it becomes more difficult to scale up suitable transmissions.
Steam trains, like electric motors, are good at supplying low-end torque. Their gear systems are fixed in the rod lengths and wheel diameters. Ships also have massive fixed reduction gears. Propellers can start moving in water from zero rpm.
For the narrow powerband rpm of diesel engines, you need multiple gears. Diesel-electrics solve that problem for large vehicles. The diesels run at their optimum rpm as generators, and electric motors lay down the instant torque to the road or track.
None of this is required for passenger vehicles, as suitable transmissions are readily available.