The first part is proportional to the difference between the
ICE and car speed and the second is proportional to the
car speed. The first part is transformed into electric
energy in the generator and supplied to the traction
motor. The second part is transferred by the output planet
shaft directly to car wheels. This scheme allows
controlling the engine speed and torque and this is the
way how to minimize fuel consumption.
Electric power splitting drive using DC machines was
used on Czechoslovak express motor cars in the year
1936. The patent document was emitted in
Czechoslovakia with Nr 53 735 on 25.February 1936.
[1], [2], [3]. DC machines were usual on railway
vehicles at that time. The vehicle was called
:”Slovenská Strela” and remained in service till the
year 1950. It should be reconstructed and modernized
later on. But electrification of the main railway
connection between Prague-Košice replaced this very
interesting vehicle with express electric locomotives.