Rotor for an electric machine, electric machine, motor vehicle and method for determining a rotor position of a rotor

A method for determining a rotor position of a rotor of an electric machine which is rotatably mounted with respect to a stator of the electric machine, the rotor having a plurality of recesses distributed along a circumferential direction and extending along a longitudinal direction, wherein geometric shapes of cross sections of the recesses differ from one another along the circumferential direction, and wherein, with regard to an assembled state of the electric machine, the recesses are each closed with respect to a radial direction towards a side of the rotor which faces the stator, the method comprising:

• producing an alternating voltage present on the part of the stator;
• generating an alternating electromagnetic field present on the part of the stator by way of the alternating voltage present on the part of the stator;
• inducing an alternating voltage present on the part of the rotor by way of the alternating field present on the part of the stator;
• generating an alternating electromagnetic field present on the part of the rotor by way of the alternating voltage present on the part of the rotor, wherein this alternating field depends on a current position of rotation of the rotor due to the differences in the geometric shapes of the cross sections of the recesses along the circumferential direction;
• inducing a feedback voltage present on the part of the stator by way of the alternating electromagnetic field present on the part of the rotor;
• and
• determining the current position of rotation of the rotor on the basis of the feedback voltage.