Electric axle drive train, control unit, and computer programme product
An electric axle drive train having an electric machine having a rotor which is mounted rotatably relative to a stator and can be supplied with current by a control unit; a gear assembly which is coupled to the rotor; and a first rotatably mounted output shaft which is operatively connected to the gear assembly in a torque-transmitting manner. An actuatable rotation blocking device is positioned in the torque flow between the rotor and the first output shaft in such a way that a rotation of the shafts lying in the torque flux can be blocked, and furthermore at least one rotational angle sensor is positioned between the rotor and the rotation blocking device in such a way that it provides a signal, that represents the rotational angle position, to a shaft lying between the rotor and the rotation blocking device.
1 . An electric axle drive train comprising:
an electric machine having a rotor which is mounted rotatably relative to a stator and is suppliable with current by a control unit; a gear assembly coupled to the rotor;
a first rotatably mounted output shaft which is operatively connected to the gear assembly in a torque-transmitting manner;
an actuatable rotation blocking device positioned in a torque flow between the rotor and the first output shaft in such that a rotation of the shafts lying in a torque flux is blockable;
at least one rotational angle sensor is positioned between the rotor and the rotation blocking device in such that the rotational angle sensor provides a signal, that represents a rotational angle position of one of the shaft lying between the rotor and the rotation blocking device;
wherein the control unit is configured to determine mechanical wear on rotatable components positioned in the torque flow between the rotor and the rotation blocking device, in that the rotation blocking device blocks the rotation of the shafts positioned in the torque flow between the rotor and the rotation blocking device, and then the electric machine is supplied with an increasing current intensity up to a predefined first current threshold value so that an increasing torque acting in a first direction of rotation is applied to the rotor, and then the electric machine is supplied with an increasing current intensity up to a predefined second current intensity threshold value so that an increasing torque acting in a second direction of rotation is applied to the rotor, and in the control unit when the electric machine is being supplied with current, the current intensity and temporally associated signals of the rotational angle sensor representing a rotational angle position are detected; and
the current intensity and the rotational angle position values are correlated to form an actual wear characteristic that is compared with a target wear characteristic stored in the control unit, wherein in the and in an event of a deviation of the actual wear characteristic from the target wear characteristic, an output signal representing the deviation is generated by the control unit;
wherein the control unit is further configured to determine a maintenance requirement of the electric axle drive train based on the output signal; and
wherein the control unit is further configured to, in response to the output signal, initiate a maintenance action for the electric machine.
2 . The axle drive train according to claim 1 , wherein a detection of the deviation of the actual wear characteristic from the target wear characteristic takes place within a rotational angle position interval stored in the control unit.
3 . The axle drive train according to claim 2 , wherein the rotational angle position interval contains a rotational angle zero point.
4 . The axle drive train according to claim 1 , wherein the output signal representing the deviation contains information about a degree of deviation, a position, and/or size of the deviation in the wear characteristics.
5 . The axle drive train according to claim 1 , wherein the rotation blocking device is at least one of a parking lock or a braking device.
6 . The axle drive train according to claim 1 , wherein the rotational angle sensor is an absolute rotational angle sensor.
7 . The axle drive train according to claim 1 , wherein the rotational angle sensor is a resolver of a permanently excited synchronous machine.
8 . The axle drive train according to claim 1 , wherein the rotational angle sensor determines the rotational angle of the rotor.
9 . The axle drive train according to claim 1 , wherein the maintenance action includes at least one of disabling or limiting operation of the electric machine, adjusting a torque output of the electric machine, placing the axle drive train into a service mode, or triggering a maintenance procedure for one or more components of the axle drive train.