Measuring coil unit and electric machine comprising a measuring coil unit of this type and method for determining operating parameters of an electric machine

2:

• The electric machine according to claim 1, comprising a plurality of stator teeth (11) in the region of a pole of the stator (10), wherein the measuring coils (35, 35a-35e) are arranged along one of the stator teeth (11) and have a width which is less than or equal to a width of the stator tooth (11).

3:

• The electric machine according to claim 1, wherein said rotor (20) comprises a plurality of mutually twisted segments (22a-22e).

4:

• The electric machine according to claim 3, wherein at least one measuring coil (35, 35a-35e) is assigned to each segment (22a-22e).

5:

• The electric machine according to claim 4, wherein the at least one measuring coil (35, 35a-35e) assigned to one of the segments (22a-22e) is positioned in such a way that said coil lies in the region of a magnetic field generated by the respective segment (22a-22e).

6:

• The electric machine according to claim 2, wherein the at least one measuring coil (35, 35a-35e) assigned to one of the segments (22a-22e) is arranged on the stator tooth (11) opposite the respective segment (22a-22e).

7:

• A measuring coil unit (30) for use in an air gap disposed between a stator (10) and a rotor (20) of an electric machine, comprising several measuring coils (35, 35a-35e) disposed adjacent to each other, wherein the measuring coils (35, 35a-35e) are arranged on an elongate carrier (31) and connections of the measuring coils (35, 35a-35e) are guided to connection contacts (38) arranged on a transverse side of the carrier (31).

8:

• The measuring coil unit (30) according to claim 7, wherein each of the measuring coils (35, 35a-35e) has at least two superimposed planar windings, with one of the windings being formed on an upper side of the carrier (31) and one of the windings on a lower side of the carrier (31).

9:

• The measuring coil unit (30) according to claim 7, wherein each of the measuring coils (35, 35a-35e) can be contacted separately via the connection contacts (38).

10:

• The measuring coil unit (30) according to claim 7, wherein the carrier (31) is a flexible film.

11:

• The measuring coil unit (30) according to claim 7, comprising electronic components for processing and/or evaluating a measuring signal of the measuring coils (35, 35a-35e).

13:

• The method according to claim 12, wherein at least one measuring coil (35, 35a-35e) is assigned to each segment (22a-22e), and at least one number of induced signals is recorded and evaluated which corresponds to the number of segments (22a-22e) of the rotor (20).

14:

• The method according to claim 12, wherein a temperature of the stator (10) is determined from an ohmic resistance of at least one of the measuring coils (35, 35a-35e).

15:

• The method according to claim 14, wherein the resistance measurement is repeatedly carried out with at least two different measuring currents and a value correlated with a convection in the air gap is determined from a difference of the resistances determined for different measuring currents.