Question about engine too wheels power

I have wondered for probably most my life how do the engines deliver the power to the wheels? I thought they had somekind of driveshaft until about a year ago.

Can someone elaborate for me how does the engine deliver the power to the driver wheels?

in most cases , the engine turns a alternator , which produces power , which is used to run electric motors that turn the wheels .

Correct....on most diesel units there is a traction motor on each axle. Electricity generated by the prime mover turning a generator or alternator is routed to the traction motors. That is why the correct term for a diesel locomotive is 'diesel-electric'. Additionally, if the locomotive is equipped with dynamic brakes those same traction motors, in dymanic brake mode, become generators. The resistance they create aid in braking the train. The excess heat is then vented through a grid and fan system of the roof of the locomotive.

Hope this helps answer your question!

Didn't the Krauss-Maffei Diesel hydraulics use some sort of direct gear drive and driveshafts? I realize that these imports were not the norm, nor were they ultimately successful when competing with native products.
It was always my impression that they worked more on an automotive principle.
Malley

The K-M units, along with the Alco DH-643, used hydraulic torque converters, much like what are used in automotive automatic transmissions. Such drive systems are fairly common in Europe - but they haven't been successful in the US.

More information on the "Alco-Haulic"

Maybe not on mainline Diesels but the hydrauling drive was very succesfull on Amtrak Turbo's and the RDC's.