Abstract: A method for the demand-responsive operation of an electric traction drive. The electric traction drive comprises a hydraulic assembly having an electric motor-driven pump unit which is actuatable in first and second directions of rotation such that a plurality of pump operating modes can be set. The motor-driven pump unit is connected via a heat-exchanger to at least two fluid outlets for partial volume flows, each of which is connected to at least one subcomponent of the electric traction drive. At least one fluid outlet is additionally opened by means of a hydraulically switchable valve, where a switchover in the direction of rotation of the motor-driven pump unit is executed. The motor-driven pump unit is activated based on measured, calculated and/or saved status data for the electric traction drive, and the direction of rotation. The pump operating mode and pump speed are regulated based on a vehicle operating mode detected.

Abstract: A rotor shaft for a rotor of an electric machine, wherein the rotor shaft is constructed as a hollow shaft and thus has a cylindrical cavity for guiding a coolant, wherein at least one bearing for supporting the rotor shaft is arranged in the cavity, wherein at least one coolant outlet is formed at least between an outer lateral surface of the bearing and an inner lateral surface of the rotor shaft, and an electric machine comprising such a rotor shaft.

Abstract: An electric machine includes a rotor shaft having a first axial bore. A passive valve for temperature-dependent flow control of the coolant is arranged in the first axial bore. The passive valve has a valve body, a valve piston axially movable within the valve body, and a valve cap fixed to the valve piston. A first valve spring biases the valve piston and the valve cap toward a closed position of the passive valve and is arranged between the valve body and the valve piston. A second valve spring formed from a shape memory alloy is arranged between the valve body and the valve cap and expands when a limit temperature is exceeded and forces the valve cap and the valve piston into an open position of the passive valve.

Abstract: A method for the demand-responsive operation of an electric traction drive. The electric traction drive comprises a hydraulic assembly having an electric motor-driven pump unit which is actuatable in first and second directions of rotation such that a plurality of pump operating modes can be set. The motor-driven pump unit is connected via a heat-exchanger to at least two fluid outlets for partial volume flows, each of which is connected to at least one subcomponent of the electric traction drive. At least one fluid outlet is additionally opened by means of a hydraulically switchable valve, where a switchover in the direction of rotation of the motor-driven pump unit is executed. The motor-driven pump unit is activated based on measured, calculated and/or saved status data for the electric traction drive, and the direction of rotation. The pump operating mode and pump speed are regulated based on a vehicle operating mode detected.

Abstract: The present disclosure relates to a cooling system for load point dependent cooling of a rotor of an electric machine. The cooling system includes at least one coolant path extending at least partially into a rotor of an electric machine. At least one passive valve is arranged in the coolant path which regulates the flow rate of the coolant through the coolant path.

Abstract: A rotor for an electric machine includes a rotor core and a rotor shaft. The rotor core is fixed on the rotor shaft. The rotor shaft has, at least in some regions, a non-circular cross-section so that, at least in some regions, a plurality of axially extending channels are formed between the rotor core and a lateral surface of the rotor shaft. At least one region with the non-circular cross-section of the rotor shaft is produced by radial forging without subsequent machining, so that the region with the non-circular cross-section of the rotor shaft has a forging skin. An electric machine may include a rotor of this type. A method for producing a rotor of this type may be performed.