A drive system for an industrial truck, comprising an internal combustion engine,
a three-shaft epicyclic gearing adapted to be connected to the shaft of the internal
combustion engine, a first electric motor which is mechanically coupled to the
second shaft of the epicyclic gearing and is connected to an onboard network of
the industrial truck, a change-speed gearing coupled to the third shaft of the
epicyclic gearing, a summing gearbox coupled to the change-speed gearing the other
input shaft of which is connected to a second electric motor which is electrically
connected to the onboard network and the output shaft of which is coupled to at
least one driven wheel of the industrial truck, a clutch (A) between the first
and second shafts of the epicyclic gearing, at least one consumption unit for an
additional function of the industrial truck that is coupled to one of the shafts
of the epicyclic gearing, a sensor device which measures the speeds of the internal
combustion engine, the first and second electric motors, and the driving wheel
and generates respective signals, and a control and regulation device which controls
or regulates the speeds of the electric motors and internal combustion engine,
and controls the motor or generator operation of the electric motors and the actuation
of the clutch (A) and change-speed gearing in response to set-point signals from
the set-point transmitters actuated by the operator of the industrial truck and
on the basis of the output signals of the sensor device.
