Method for operating a drive train for driving a working machine with variable rotation speed and drive train

A method for operating a drive train for driving a working machine with variable rotation speed, the drive train having an electric drive machine operable at a constant rotation speed and a power transmission device,

• wherein the power transmission device containing:
• an input for at least indirect connection to the electric drive machine;
• an output for at least indirect connection to the working machine;
• a hydrodynamic rotation speed/torque converter containing vane wheels including at least a pump vane wheel, a turbine vane wheel and a guide wheel, and form a working chamber that can be filled with and operating medium;
• a superposition gear mechanism with at least one planetary gear mechanism having a ring gear, a sun wheel and a planet carrier with several planet wheels as elements of the planetary gear mechanism;
• the input of the power transmission device is connected at least indirectly to the pump wheel of the hydrodynamic rotation speed/torque converter and to a first element of the planetary gear mechanism;
• the turbine van wheel of the hydrodynamic rotation speed/torque converter is connected at least indirectly to a second element of the planetary gear mechanism;
• and
• a third element of the planetary gear mechanism is connected at least indirectly to or forms the output of the power transmission device;
• an operating medium supply and/or guidance system assigned at least to the hydrodynamic rotation speed/torque converter;
• and
• a device for influencing a filling state of the hydrodynamic rotation speed/torque converter;
• the method which comprises the following steps of:
• running up the electric drive machine from a standstill, with the hydrodynamic rotation speed/torque converter evacuated, to a predefined value which at least indirectly characterizes an operating mode of the electric drive machine;
• simultaneously with reaching the predefined value which at least indirectly characterizes the operating mode of the electric drive machine or with a temporal offset after reaching the predefined value, filling the hydrodynamic rotation speed/torque converter and driving the turbine wheel;
• and
• driving the third element of the planetary gear mechanism with a rotation speed which results from a superposition, defined by the planetary gear mechanism, of a rotation speed of the first element of the planetary gear mechanism connected to the electric drive machine and a rotation speed of the second element of the planetary gear mechanism which is at least indirectly connected to the turbine wheel.