Rotor for an Electric Machine and Electric Machine Having a Rotor

Abstract

A rotor (1) for an electric machine (2) includes a rotor body with multiple poles. Multiple flux barriers (6.1, 6.2, 6.3, 6.4) are formed in the interior of the rotor body. The rotor (1) further includes at least one sensor element (3) configured for detecting at least one condition variable of the rotor (1), a signal processing unit (4) connected to the at least one sensor element (3) and configured for generating measured data from the detected condition variable of the rotor (1) and transmitting the measured data to a control device (5), and at least one induction coil (7) that includes at least one electrical conductor (8), is arranged in at least one flux barrier (6.1) of the rotor (1), and is configured for generating electrical energy from a leakage magnetic field in this flux barrier (6.1).

Claims

1-15: (canceled)

16. A rotor (1) for an electric machine (2), comprising: a rotor body with a plurality of poles and a plurality of flux barriers (6.1, 6.2, 6.3, 6.4) formed in an interior of the rotor body; at least one sensor (3) configured for detecting at least one condition variable of the rotor (1); a signal processing unit (4) connected to the at least one sensor (3) and configured for generating measured data from the detected condition variable of the rotor (1) and for transmitting the measured data to a control device (5); and at least one induction coil (7) that comprises at least one electrical conductor (8), the at least one induction coil (7) arranged in at least one flux barrier (6.1) of the plurality of flux barriers and configured for generating electrical energy from a leakage magnetic field in the at least one flux barrier (6.1) of the plurality of flux barriers.

17. The rotor (1) of claim 16, wherein the at least one induction coil (7) is configured for supplying one or both of the signal processing unit (4) and the at least one sensor (3) with electrical energy.

18. The rotor (1) of claim 16, wherein: the at least one conductor (8) of the at least one induction coil (7) extends in a first direction in a first area (9.1) of the flux barrier (6.1); and the at least one conductor (8) of the at least one induction coil (7) extends in a second direction in a second area (9.2) of the flux barrier (6.1), the second direction being opposite the first direction.

19. The rotor (1) of claim 16, wherein the at least one conductor (8) of the at least one induction coil (7) is wound around a carrier (10).

20. The rotor (1) of claim 19, wherein the carrier (10) is formed from a non-magnetizable material.

21. The rotor (1) of claim 19, wherein the carrier (10) is formed from one or more of a polymer material, a ceramic, a glass, and a resin.

22. The rotor (1) of claim 16, wherein the at least one conductor (8) of the at least one induction coil (7) is at least partially fixed with a varnish (16).

23. The rotor (1) of claim 16, wherein the at least one conductor (8) of the at least one induction coil (7) is at least partially fixed with an encapsulation (12).

24. The rotor (1) of claim 16, wherein the signal processing unit (4) is arranged on an end face of the rotor (1).

25. The rotor (1) of claim 16, wherein the at least one sensor (3) is integrated in the signal processing unit (4).

26. The rotor (1) of claim 16, wherein the at least one sensor (3) is arranged in the interior of the rotor (1).

27. The rotor (1) of claim 16, further comprising at least one permanent magnet (15.1), each of the at least one permanent magnet (15.1) arranged proximate a respective pole of the plurality of poles.

28. The rotor (1) of claim 16, wherein at least two permanent magnets (15.1, 15.2) are radially spaced apart from one another and are arranged proximate each pole of the plurality of poles.

29. The rotor (1) of claim 16, wherein at least one of the plurality of flux barriers (6.1) is arranged proximate each pole of the plurality of poles.

30. An electric machine (2), comprising: a control device (5) configured for open-loop control of the electric machine (2); a stator (11); and the rotor (1) of claim 16.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Multiple preferred example embodiments of the invention are explained in greater detail in the following with reference to the drawings, wherein identical elements are labeled with the same reference character, wherein

[0032] FIG. 1 shows a highly simplified schematic of a vehicle including an electric machine according to example aspects of the invention,

[0033] FIG. 2 shows a highly simplified diagrammatic longitudinal sectional representation of the electric machine according to example aspects of the invention including a stator and a rotor,

[0034] FIG. 3 shows a highly simplified diagrammatic cross-sectional representation of the electric machine according to example aspects of the invention, according to FIG. 2,

[0035] FIG. 4 shows a highly simplified detailed schematic of a section of the electric machine according to example aspects of the invention, according to FIG. 3,

[0036] FIG. 5 shows a highly simplified detailed schematic of a section of the electric machine according to example aspects of the invention, according to a second exemplary embodiment, and

[0037] FIG. 6 shows a highly simplified detailed schematic of a section of the electric machine according to example aspects of the invention, according to a third exemplary embodiment.

DETAILED DESCRIPTION

[0038] Reference will now be made to embodiments of the invention, one or more examples of which are shown in the drawings. Each embodiment is provided by way of explanation of the invention, and not as a limitation of the invention. For example, features illustrated or described as part of one embodiment can be combined with another embodiment to yield still another embodiment. It is intended that the present invention include these and other modifications and variations to the embodiments described herein.

[0039] According to FIG. 1, a vehicle 100 includes an electric machine 2 according to example aspects of the invention, which is configured for driving the vehicle 100. For this purpose, the electric machine 2 is drivingly connected, for example, via shafts 17 and, optionally, via further components, to driving wheels 20 of the vehicle 100. Moreover, the electric machine 2 is actuated and operated by a control device 5, which is arranged in the vehicle 100. In particular, the control device 5 is utilized for protecting the electric machine 2 against overheating during the operation, in that the maximum power of the electric machine 2 is adapted, in particular to a currently measured temperature of the rotor 1. For this purpose, the control device 5 is connected to the electric machine 2 in a signal-transmitting manner.

[0040] FIG. 2 shows the electric machine 2, which includes the control device 5 for the open-loop control of the electric machine 2, and a stator 11 and a rotor 1. An air gap 18 is formed between the stator 11 and the rotor 1. The rotor 1 is rotationally fixed to a rotor shaft 14. In the housing 13 of the electric machine 2, a signal processing unit 4 including a sensor element 3 is arranged on an end face of the rotor 1. The at least one sensor element 3 is integrated in the signal processing unit 4. Alternatively, the sensor element 3 can be arranged in the interior of the rotor 1. In the present case, the longitudinal section extends through first and second permanent magnets 15.1, 15.2, which are arranged in the rotor body of the rotor 1.

[0041] FIG. 3 shows the electric machine 2 in a cross-section. The rotor 1 is rotatably arranged in the interior of the stator 11, wherein an air gap 18 is formed between the stator 11 and the rotor 1. The stator 11 has a stator body designed as a stator laminated core as well as multiple coils 21 accommodated by the stator body. The rotor 1 has a rotor body designed as a rotor laminated core and multiple first and second permanent magnets 15.1, 15.2 arranged in the interior of the rotor body. The permanent magnets 15.1, 15.2 arranged in the interior of the rotor laminated core are also referred to as buried permanent magnets. These permanent magnets 15.1, 15.2 form six poles in the present case. A first and a second permanent magnet 15.1, 15.2 radially spaced apart from one another as well as a first, second, third, and fourth flux barrier 6.1, 6.2, 6.3, 6.4 are arranged in the area of each pole. The flux barriers 6.1 and 6.3 as well as 6.2 and 6.4 are also arranged radially spaced apart from one another. One flux barrier 6.1 and 6.2 as well as 6.3 and 6.4 is arranged in the circumferential direction on each side of the permanent magnets 15.1, 15.2, respectively.

[0042] In the present case, an induction coil 7 is arranged in a single flux barrier 6.1 of the rotor 1 and is configured for generating electrical energy from the leakage magnetic field in this flux barrier 6.1 in order to supply the sensor element 3 and the signal processing unit 4 with electrical energy. Alternatively, induction coils 7 can be arranged in further flux barriers 6.1, 6.2, 6.3, 6.4 of the rotor 1 in order to generate electrical energy from the leakage magnetic field of the particular flux barrier 6.1, 6.2, 6.3, 6.4. The induction coil 7 is connected via a wiring 19 to the signal processing unit 4 and the sensor element 3 integrated therein. In order to convert the alternating current to direct current and provide the direct current for the sensor element 3, the signal processing unit 4 has, for example, an oscillating circuit (not represented in greater detail, but generally known), a rectifier, and at least one capacitor, alternatively, other energy accumulators.

[0043] The sensor element 3 measures a temperature at the rotor 1 as a condition variable of the rotor 1 and transmits this condition variable to the signal processing unit 4. Optionally, multiple sensor elements 3 can be arranged at the rotor 1, which detect, for example, different condition variables of the rotor 1. The signal processing unit 4 generates measured data from the detected condition variables of the rotor 1 and transmits the measured data to the control device 5 installed in the vehicle 100. The control device 5 is connected to the signal processing device 4 at the rotor 1 wirelessly, for example, via radio, and is configured for actuating the electric machine 2 under consideration of demands of a driver as well as operating parameters of the electric machine 2, in particular, operating parameters and/or condition variables of the rotor 1.

[0044] With the induction coil 7, it is possible to generate electrical energy during the operation of the electric machine 2. The leakage magnetic field of a changing magnetic field in the flux barrier 6.1 flows through the induction coil 7 during the operation of the electric machine 2, i.e., when the rotor 1 is rotating, as the result of which an electric current or a voltage is induced in the particular induction coil 7, which is utilized for supplying electrical energy to the sensor element 3 and the signal processing unit 4, which are arranged at the rotor 1 in a rotationally fixed manner and rotate together with the rotor 1.

[0045] FIG. 4 shows an enlarged section of the electric machine 2 from FIG. 3. A conductor 8 of the induction coil 7 extends in a first direction in a first area 9.1 of the flux barrier 6.1 and, in a second area 9.2 of the flux barrier 6.1, extends back from the first direction. The position of the induction coil 7 in the flux barrier 6.1 and the size of the induction coil 7, i.e., the distance between a forward-conductor section 8.1 and a return-conductor section 8.2 of the conductor 8, are matched to strongly present orders of a harmonic field of the electric machine 2. In the present case, the conductor 8 is wound around a carrier 10, wherein the carrier 10 is formed from a non-magnetizable material, in particular from a polymer material.

[0046] The example embodiment of the rotor 1 according to FIG. 5 differs from the example embodiment of the rotor 1 according to FIG. 4 only in that the conductor 8 of the induction coil 7 is not wound around a carrier, but rather is at least partially fixed with a varnish 16. The varnish 16 is applied onto the surface of the conductor 8 and, when drying, cures in such a way that a resistance to deformation of the conductor 8 wetted with varnish 16 is increased, and so the imparted shape of the induction coil 7 is maintained, also without a carrier, during the operation of the electric machine 2.

[0047] The example embodiment of the rotor 1 according to FIG. 6 differs from the example embodiment of the rotor 1 according to FIG. 4 only in that the conductor 8 of the induction coil 7 is not wound around a carrier, but rather is at least partially fixed with an encapsulation 12. The conductor 8 is embedded in the viscous encapsulation 12, wherein the encapsulation 12, when drying, cures in such a way that the fixation of the conductor 8 in the encapsulation 12 takes place, and so the imparted shape of the induction coil 7 is maintained during the operation of the electric machine 2. Consequently, the encapsulation 12 performs the function of a carrier.

[0048] Modifications and variations can be made to the embodiments illustrated or described herein without departing from the scope and spirit of the invention as set forth in the appended claims. In the claims, reference characters corresponding to elements recited in the detailed description and the drawings may be recited. Such reference characters are enclosed within parentheses and are provided as an aid for reference to example embodiments described in the detailed description and the drawings. Such reference characters are provided for convenience only and have no effect on the scope of the claims. In particular, such reference characters are not intended to limit the claims to the particular example embodiments described in the detailed description and the drawings.

REFERENCE CHARACTERS

[0049] 1 rotor [0050] 2 electric machine [0051] 3 sensor element [0052] 4 signal processing unit [0053] 5 control device [0054] 6.1 flux barrier [0055] 6.2 flux barrier [0056] 6.3 flux barrier [0057] 6.4 flux barrier [0058] 7 induction coil [0059] 8 electrical conductor [0060] 8.1 forward-conductor section [0061] 8.2 return-conductor section [0062] 9.1 first area [0063] 9.2 second area [0064] 10 carrier [0065] 11 stator [0066] 12 encapsulation [0067] 13 housing [0068] 14 rotor shaft [0069] 15.1 first permanent magnet [0070] 15.2 second permanent magnet [0071] 16 varnish [0072] 17 shaft [0073] 18 air gap [0074] 19 wiring [0075] 20 driving wheel [0076] 21 coil [0077] 100 vehicle