Rotor for an Electric Machine and Electric Machine Having a Rotor

Abstract

A rotor (1) for an electric machine (2) includes at least one sensor element (3) configured for detecting condition variables 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 variables of the rotor (1) and transmitting the measured data to a control device (5), and a nanogenerator (6) configured for generating electrical energy from at least one surroundings variable and supplying the at least one sensor element (3) and the signal processing unit (4) with electrical energy.

Claims

1-15: (canceled)

16. A rotor (1) for an electric machine (2), comprising: 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 a nanogenerator (6) configured for generating electrical energy from at least one surroundings variable and supplying the at least one sensor element (3) and the signal processing unit (4) with the electrical energy.

17. The rotor (1) of claim 16, wherein the nanogenerator (6) is ring-shaped and arranged circumferentially at the rotor (1).

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

19. The rotor (1) of claim 16, wherein the nanogenerator (6) comprises a thermocouple.

20. The rotor (1) of claim 16, wherein the nanogenerator (6) is arranged on an end face of the rotor (1).

21. The rotor (1) of claim 16, further comprising a cooling ring (7) arranged on an end face of the rotor (1), wherein the cooling ring (7) at least partially or completely covers the nanogenerator (6).

22. The rotor (1) of claim 21, wherein a side of the nanogenerator (6) or the cooling ring (7) facing away from the rotor (1) is configured to be at least partially sprayed with a coolant (8).

23. The rotor (1) of claim 21, wherein the cooling ring (7) is formed from a steel alloy, an aluminum alloy, or a copper alloy.

24. The rotor (1) of claim 21, wherein the cooling ring (7) has a thermal conductivity no less than forty watts per meter-Kelvin.

25. The rotor (1) of watts per meter-Kelvin, wherein the cooling ring (7) is spaced apart from the signal processing unit (4) and does not cover the signal processing unit (4).

26. The rotor (1) of watts per meter-Kelvin, wherein the cooling ring (7) comprises a fin structure (9).

27. The rotor (1) of claim 26, wherein the fin structure (9) comprises a plurality of fins (9.1) extending radially from an inner circumference to an outer circumference of the cooling ring (7) and uniformly spaced apart from one another in a circumferential direction.

28. The rotor (1) of claim 26, wherein the fin structure (9) comprises a plurality of fins (9.2) extending in a circumferential direction and radially uniformly spaced apart from one another.

29. The rotor (1) of claim 16, wherein a side of the nanogenerator (6) facing away from the rotor (1) is configured to be at least partially sprayed with a coolant (8).

30. An electric machine (2), comprising: a coolant system (10) for cooling the electric machine (2); a control device (5) for the open-loop control of the electric machine (2); a stator (11); and the rotor (1) of claim 16, wherein at least one spray nozzle (12) of the coolant system (10) is configured for cooling the nanogenerator (6) with a coolant (8).

31. A vehicle (100), comprising the electric machine (2) of claim 30.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] 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

[0027] FIG. 1 shows a highly simplified schematic of a vehicle including an electric machine according to example aspects of the invention,

[0028] FIG. 2 shows a highly simplified diagrammatic sectioning of the electric machine according to example aspects of the invention including a stator and a rotor,

[0029] FIG. 3 shows a highly simplified perspective schematic of the rotor according to example aspects of the invention of the electric machine according to FIG. 2,

[0030] FIG. 4 shows a highly simplified perspective schematic of the rotor according to example aspects of the invention, according to a second exemplary embodiment,

[0031] FIG. 5 shows a highly simplified perspective schematic of the rotor according to example aspects of the invention, according to a third exemplary embodiment, and

[0032] FIG. 6 shows a highly simplified perspective schematic of the rotor according to example aspects of the invention, according to a fourth exemplary embodiment.

DETAILED DESCRIPTION

[0033] 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.

[0034] 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.

[0035] FIG. 2 shows the electric machine 2, which includes a coolant system 10 for cooling the electric machine 2, 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 spray nozzle 12 of the coolant system 10 is configured for cooling a nanogenerator 6 with a coolant 8. The nanogenerator 6 is arranged on an end face of the rotor 1. In addition to the nanogenerator 6, a sensor element 3 and a signal processing unit 4 are also fixedly arranged on an end face of the rotor 1. The spray nozzle 12 sprays the coolant 8 onto the rotor 1 on an end face and, in fact, in the area of the rotor 1 where the nanogenerator 6 is arranged.

[0036] In FIG. 3, the rotor 1 of the electric machine 2 according to FIG. 2 is represented in an enlarged and perspective view. FIG. 3 shows one of the two end faces of the rotor 1, wherein the end-face arrangement of the nanogenerator 6, the sensor element 3, and the signal processing unit 4 is represented. In the present case, the sensor element 3 is integrated in the signal processing unit 4 and, thereby, is arranged within the signal processing unit 4. Consequently, the sensor element 3 and the signal processing unit 4 form a unit. Moreover, multiple magnets 15 are arranged in the laminated core of the rotor 1 and a central recess 16 is formed in the laminated core of the rotor 1. Two magnets 15 form one pole in each case, wherein a total of six poles are formed at the rotor 1 in the present case. The rotor shaft is hidden in the present case and, thereby, is not represented.

[0037] 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. According to FIG. 2, 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.

[0038] Energy harvesting is performed in order to supply the sensor element 3 and the signal processing unit 4 with electrical energy, wherein, in the present case, the nanogenerator 6 is designed as a thermocouple and the electrical energy is generated from a temperature difference between two sides of the nanogenerator 6. When the rotor 1 heats up, the side of the nanogenerator 6 with which the nanogenerator 6 is attached at the rotor 1 heats up to a greater extent than the side of the nanogenerator 6 that faces away from the rotor 1 and faces the surroundings. This outwardly facing side of the nanogenerator 6 is actively cooled in the present case via coolant 8 from the spray nozzle 12 of the coolant system 10, and so the temperature difference between the outer side and the inner side of the nanogenerator 6 is increased and, as a result, the voltage that the nanogenerator 6 generates is also increased. The nanogenerator 6 is arranged at an end-face segment of the rotor 1 and, thereby, does not extend over the entire circumference at the end face of the rotor 1. In the present case, the nanogenerator 6 is designed to be rectangular and particularly compact. The nanogenerator 6 is connected to the signal processing unit 4 and the sensor element 3 arranged therein via a first electrical line 19.1 and a second electrical line 19.2.

[0039] The example embodiment of the rotor 1 according to FIG. 4 differs from the example embodiment of the rotor 1 according to FIG. 3 in that the nanogenerator 6 merely has a different shape, namely is designed circumferentially at the rotor 1 in the shape of a ring. Therefore, reference is made to the above-described first example embodiment of the rotor 1 according to FIG. 3. The nanogenerator 6 formed circumferentially at the rotor 1 in the shape of a ring has the advantage that, during the entire revolution of the rotor 1, coolant 8 from a single spray nozzle 12 cools the outwardly directed side of the nanogenerator 6 continuously and not only in the instant in which the nanogenerator 6 passes the spray nozzle 12 during the revolution. The ring-shaped nanogenerator 6 has an outer circumference and an inner circumference and is arranged coaxially to the central recess 16.

[0040] The example embodiment of the rotor 1 according to FIG. 5 differs from the example embodiment of the rotor 1 according to FIG. 3 in that a cooling ring 7 is arranged on an end face of the rotor 1 and, in fact, in such a way that the cooling ring 7 completely covers the nanogenerator 6. Therefore, the nanogenerator 6 is not visible in FIG. 5, although the nanogenerator 6 is designed and arranged in the identical manner as the nanogenerator 6 according to FIG. 3. Reference is therefore made to the above-described first example embodiment of the rotor 1 according to FIG. 3. The cooling ring 7 is designed circumferentially at the rotor 1 in the shape of a ring and is fixedly connected to the rotor 1 and the nanogenerator 6. In the present case, the cooling ring 7 is made of an aluminum alloy, which forms a good compromise between a sufficient strength for maximum rotational speeds of the rotor 1 and a good thermal conductivity for the better cooling of the outwardly directed side of the nanogenerator 6.

[0041] The cooling ring 7 has an outer circumference and an inner circumference and is arranged coaxially to the central recess 16. Moreover, the cooling ring 7 is arranged spaced apart from the signal processing unit 4 and does not cover the signal processing unit 4. Moreover, the cooling ring 7 has a fin structure 9, wherein the fin structure 9 includes multiple fins 9.1 extending radially from an inner circumference to an outer circumference of the cooling ring 7 and formed uniformly spaced apart from one another in the circumferential direction. Due to the fin structure 9, the surface of the cooling ring 7 is increased and, as a result, the cooling potential is also increased.

[0042] The example embodiment of the rotor 1 according to FIG. 6 differs from the example embodiment of the rotor 1 according to FIG. 5 merely in that the cooling ring 7 has a different fin structure 9. Therefore, reference is made to the above-described third example embodiment of the rotor 1 according to FIG. 5 and to the reference made there to FIG. 3. The fin structure 9 of the cooling ring 7 is made up of multiple fins 9.2 formed extending in the circumferential direction, which are designed to be radially uniformly spaced apart from one another. Each of the fins 9.2 forms a closed circle. The circumferentially formed fins 9.2 are arranged coaxially to the central recess 16.

[0043] In one alternative example embodiment (not represented here) of the rotor 1, the cooling ring 7 is designed without a fin structure. Consequently, the cooling ring 7 has an essentially smooth surface, instead of cooling fins. A cooling ring 7 of this type essentially corresponds to the nanogenerator 6 according to FIG. 4 with respect to shape and arrangement.

[0044] 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

[0045] 1 rotor [0046] 2 electric machine [0047] 3 sensor element [0048] 4 signal processing unit [0049] 5 control device [0050] 6 nanogenerator [0051] 7 cooling ring [0052] 8 coolant [0053] 9 fin structure [0054] 9.1 radially extending fins [0055] 9.2 circumferential fins [0056] 10 coolant system [0057] 11 stator [0058] 12 spray nozzle [0059] 13 housing [0060] 14 rotor shaft [0061] 15 magnet [0062] 16 recess [0063] 17 shaft [0064] 18 air gap [0065] 19.1 first electrical line [0066] 19.2 second electrical line [0067] 20 driving wheel [0068] 100 vehicle