Rotating electric machines

Abstract

A rotating electric machine includes a stator, a rotor provided with a permanent magnet, a first number of first coils, and a second number of second coils different from the first number. The first coil is arranged on the stator in a manner that the coil axis is along the direction of the rotation axis of the rotor. The second coil is arranged on the rotor in a manner that the coil axis is along the direction of the rotation axis of the rotor. The first coil and the second coil are arranged on the stator and the rotor, respectively, in a manner that they are close to each other and face each other when the rotor is at a predetermined rotation angle position. The first coil is configured to induce a voltage according to the relative position with the second coil.

Description

Technical Field

[0001] One aspect of the present invention relates to a rotating electrical machine. Background Art

[0002] A known rotating electrical machine includes a stator and a rotor on which permanent magnets are arranged, and a known rotation position detection device is configured to detect a rotation angle position of the rotor (for example, refer to Japanese Patent Application Laid-Open No. 2009-098050). Summary of the invention

[0003] The rotation position detection device includes a rotor fixed to the rotating shaft of the rotating electric machine and a stator facing the rotor. Therefore, the unit composed of the rotating electric machine and the rotation position detection device has to be large in size.

[0004] An object of one aspect of the present invention is to provide a rotating electrical machine that can detect a rotation angle position of a rotor while suppressing an increase in size.

[0005] A rotating electric machine of one embodiment includes a stator, a rotor provided with permanent magnets, a first number of first coils, and a second number of second coils different from the first number. The first number of first coils are arranged on the stator in a manner such that the coil axes are along the direction of the rotation axis of the rotor. The second number of second coils are arranged on the rotor in a manner such that the coil axes are along the direction of the rotation axis of the rotor. The first coil and the second coil are arranged on the stator and the rotor, respectively, in a manner such that they are close to each other and face each other when the rotor is at a predetermined rotation angle position. The first coil is configured to induce a voltage corresponding to the relative position with the second coil.

[0006] In the above-mentioned embodiment, the first coil and the second coil are respectively arranged on the stator and the rotor in such a manner that they are close to each other and face each other when the rotor is at a predetermined rotation angle position, and the first coil is configured to induce a voltage according to the relative position with the second coil. Therefore, in the above-mentioned embodiment, the rotation angle position of the rotor can be detected by detecting the voltage of the first coil.

[0007] The first coil and the second coil are arranged on the stator and the rotor respectively so that the coil axes are along the rotation axis direction of the rotor and they are close to each other and face each other when the rotor is at a predetermined rotation angle position. Therefore, the rotary electric machine is difficult to be enlarged.

[0008] In the above aspect, each of the first and second coils may include a coil conductor having a spiral shape in a plan view.

[0009] In the structure in which the first and second coils have the coil conductors, when the first coil and the second coil are closely opposed, the magnetic coupling between the first coil and the second coil increases. Therefore, this structure improves the detection accuracy of the rotation angle position of the rotor.

[0010] In the above-mentioned embodiment, the rotor may include: a temperature sensing element configured to change resistance according to the temperature of the permanent magnet; a third coil electrically connected to the temperature sensing element; and an element configured to output an electrical signal corresponding to the voltage induced by the first coil. In this case, the temperature sensing element and the third coil are arranged on the rotor.

[0011] By placing the first coil and the third coil in close opposition, the first coil excites the third coil, thereby supplying power to the third coil. The resistance of the temperature sensing element electrically connected to the third coil changes according to the temperature of the permanent magnet, and therefore, the voltage generated in the first coil changes according to the change in the resistance of the temperature sensing element. The element outputs an electrical signal corresponding to the voltage induced in the first coil. Therefore, the electrical signal output from the element changes according to the temperature of the permanent magnet. As a result, even when the temperature sensing element is provided on the rotor, the structure having the temperature sensing element, the third coil and the element appropriately and simply outputs temperature information about the temperature of the permanent magnet.

[0012] In the above aspect, a capacitance component that forms an LC resonance circuit with the third coil may be provided.

[0013] The structure with a capacitive component sensitively detects changes in the resistance of the temperature sensing element.

[0014] In the above aspect, the third coil may include a coil conductor having a spiral shape in a plan view.

[0015] In the structure in which the third coil has the coil conductor, when the first coil and the third coil are closely opposed, the magnetic coupling between the first coil and the third coil increases. Therefore, this structure outputs temperature information about the temperature of the permanent magnet more appropriately.

[0016] The present invention will be more fully understood from the following detailed description and accompanying drawings, which are given for the purpose of illustration only and thus are not to be considered as limiting the present invention.

[0017] According to the following detailed description, the further applicable scope of the present invention will become apparent. However, it should be understood that although embodiments of the present invention are shown, the detailed description and specific examples are given by way of example only while illustrating embodiments of the present invention, and various changes and modifications within the spirit and scope of the present invention are apparent to those skilled in the art. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram showing the structure of a rotating electrical machine according to one embodiment.

[0019] Figure 2 (a) and (b) are circuit diagrams showing an example of each element unit.

[0020] Figure 3 (a), (b) and (c) are circuit diagrams showing examples of each element unit.

[0021] Figure 4 (a) and (b) are schematic diagrams showing an example of the position of the coil included in each element unit.

[0022] Figure 5 (a) and (b) are diagrams showing the structure of the coil included in each element unit.

[0023] Figure 6 (a) and (b) are graphs showing an example of changes in the voltage amplitude of the coil.

[0024] Figure 7 (a) and (b) are line graphs showing the voltage amplitude of the coil.

[0025] Figure 8 (a) and (b) are schematic diagrams showing another example of the position of the coil included in each element unit.

[0026] Fig. 9 (a), (b), (c), and (d) are graphs showing another example of changes in the voltage amplitude of the coil. DETAILED DESCRIPTION

[0027] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, the same reference numerals are used for the same elements or elements having the same functions, and repeated descriptions are omitted.

[0028] Reference Figure 1 to Figure 5 , the structure of the rotating electrical machine MT of the present embodiment will be described. Figure 1 It is a schematic diagram showing the structure of the rotating electrical machine according to the present embodiment. Figure 2 (a) and (b), and Figure 3 (a), (b) and (c) are circuit diagrams showing examples of each element unit. Figure 4 (a) and (b) are schematic diagrams showing an example of the position of the coil included in each element unit. Figure 5 (a) and (b) are diagrams showing the structure of the coil included in each element unit.

[0029] The rotating electrical machine MT is, for example, an electric motor. The electric motor includes, for example, an IPM motor or an SPM motor. The rotating electrical machine MT includes a stator 10 and a rotor 20. The rotor 20 is located inside the stator 10.

[0030] The rotor 20 includes a shaft 21, a rotor core 23, and a plurality of permanent magnets 25. The shaft 21 is cylindrical. The rotor core 23 is cylindrical. An axial hole into which the shaft 21 is inserted is formed on the rotor core 23. The shaft 21 and the rotor core 23 rotate integrally around the central axis of the shaft 21. Each permanent magnet 25 is arranged on the rotor core 23 in such a manner that its extension direction is parallel to the central axis of the shaft 21. The extension direction of each permanent magnet 25 is substantially parallel to the central axis of the shaft 21. The central axis of the shaft 21 is the rotation axis RA of the rotor 20. The direction in which the rotation axis RA of the rotor 20 extends is the rotation axis direction DA of the rotor 20. The plurality of permanent magnets 25 are arranged at equal angular intervals with respect to the rotation axis RA of the rotor 20.

[0031] When the rotating electrical machine MT is an IPM motor, a plurality of permanent magnets 25 are arranged in the rotor core 23. When the rotating electrical machine MT is an SPM motor, a plurality of permanent magnets 25 are arranged on the surface of the rotor core 23. Each permanent magnet 25 includes a rare earth permanent magnet. Each permanent magnet 25 is, for example, a neodymium sintered magnet. Each permanent magnet 25 may be a sintered magnet other than a rare earth permanent magnet, or may be a magnet other than a sintered magnet. Magnets other than sintered magnets include, for example, bonded magnets or hot-processed magnets.

[0032] The stator 10 includes a cylindrical stator core (not shown) and a plurality of coils 11. The stator core is arranged to surround the outer circumference of the rotor 20. An air gap of uniform width is provided between the stator 10 and the rotor 20. The stator core holds the plurality of coils 11. Each coil 11 is arranged on the inner circumference side of the stator core. The plurality of coils 11 are arranged at equal angular intervals with respect to the rotation axis RA of the rotor 20.

[0033] The rotating electric machine MT is connected to a control circuit 41. The control circuit 41 is connected to a power supply 43. The control circuit 41 adjusts the drive current from the power supply 43 and supplies three-phase AC power to each coil 11. The control circuit 41 controls the value of the three-phase AC power supplied to each coil 11. The control circuit 41 includes, for example, an inverter circuit. By supplying three-phase AC power to each coil 11, each coil 11 forms a rotating magnetic field that rotates the rotor 20. The power supply 43 includes, for example, an electrical energy storage device. The electrical energy storage device includes, for example, a secondary battery or a capacitor.

[0034] The rotating electrical machine MT includes a plurality of element units E1, E2, E3, and E4. The rotating electrical machine MT includes a plurality of element units E1, E2, E3, and E4. In the present embodiment, four element units E1, E2, E3, and E4 are disposed in the rotating electrical machine MT.

[0035] Also like Figure 2 As shown in (a) of FIG. 1 , the element unit E1 has a coil 51a. Figure 2As shown in (b), the element unit E2 has a coil 51b. Each element unit E1 and E2 is connected to the control circuit 41. Figure 3 As shown in (a) of FIG. 1 , the element unit E3 has a coil 61a. Figure 3 As shown in (b) of FIG. 8 , the element unit E4 has a coil 61 b ​​.

[0036] Also like Figure 4 As shown in (a) of FIG. 1 , the coil 51a of the element unit E1 and the coil 51b of the element unit E2 are arranged on the stator 10. Each coil 51a, 51b is arranged on, for example, a stator core. Figure 4 As shown in (b), the coil 61a of the element unit E3 and the coil 61b of the element unit E4 are arranged on the rotor 20. The coils 51a, 51b and the coils 61a, 61b are arranged on the stator 10 and the rotor 20 respectively in such a manner that they are close to each other and face each other when the rotor 20 is at a predetermined rotation angle position. In the present embodiment, the coils 51a, 51b and the coils 61a, 61b are close to each other and face each other in a direction substantially parallel to the rotation axis direction DA when the rotor 20 is at a predetermined rotation angle position.

[0037] like Figure 4 As shown in (a) of FIG. 1 , the coil 51a and the coil 51b are located at a predetermined first angle relative to each other at the rotation angle of the rotor 20. Figure 4 As shown in (b), the coil 61a and the coil 61b are located at a predetermined second angle from each other at the rotation angle of the rotor 20. The first angle is, for example, about 90° (or about 270°), and the second angle is, for example, about 180°. The coils 51a, 51b, 61a, and 61b are arranged in the rotating electrical machine MT. The rotating electrical machine MT includes the coils 51a, 51b, 61a, and 61b.

[0038] In the case where the coils 51a and 51b constitute, for example, the first coil, the coil 61a constitutes the second coil, and the coil 61b constitutes the third coil. The number of coils 51a and 51b included in the element unit E1 and the element unit E2 is different from the number of coils 61a included in the element unit E3. In the present embodiment, the number of coils 51a and 51b included in the element unit E1 and the element unit E2 is greater than the number of coils 61a included in the element unit E3. The number of coils 51a and 51b included in the element unit E1 and the element unit E2 is two, and the number of coils 61a included in the element unit E3 is one. In the case where the number of coils 51a and 51b included in the element unit E1 and the element unit E2 is, for example, the first number, the number of coils 61a included in the element unit E3 is the second number.

[0039] As shown in FIG. 2( a ), the element unit E1 also includes an AC power source 52, an AC power source 53, a resistor 54, a low-pass filter 55, a voltage monitor 56, a high-pass filter 57, and a voltage monitor 58. Figure 2 As shown in (b), the element unit E2 also has an AC power supply 53, a resistor element 54, a low-pass filter 55, and a voltage monitor 56. Each element unit E1 and E2 is connected to the control circuit 41. The AC power supply 52, the AC power supply 53, the resistor element 54, the low-pass filter 55, the voltage monitor 56, the high-pass filter 57, and the voltage monitor 58 are arranged outside the rotating electrical machine MT. The low-pass filter 55, the voltage monitor 56, the high-pass filter 57, and the voltage monitor 58 can also be arranged, for example, inside the rotating electrical machine MT.

[0040] First, the structure of the element unit E1 will be described.

[0041] The AC power supply 52 is electrically connected to the coil 51a, and applies an AC signal (AC voltage) of a specified first frequency to the coil 51a. The AC power supply 53 is also electrically connected to the coil 51a, and applies an AC signal (AC voltage) of a specified second frequency to the coil 51a. The first frequency and the second frequency are different. In the present embodiment, the first frequency is greater than the second frequency. The first frequency is, for example, 100 kHz. The second frequency is, for example, 20 kHz. In the element unit E1, the AC signal of the first frequency and the AC signal of the second frequency overlap. The overlapping AC signal of the first frequency and the AC signal of the second frequency are applied to the coil 51a. The first and second frequencies are 10 to 200 times the drive frequency of the rotating motor MT.

[0042] The voltage monitor 56 is electrically connected to the coil 51a through the low-pass filter 55. The low-pass filter 55 allows a voltage signal in a predetermined frequency band including the second frequency to pass through. The voltage monitor 56 monitors the voltage signal in a predetermined frequency band including the second frequency that passes through the low-pass filter 55 in the voltage signal reflecting the voltage induced in the coil 51a. The voltage monitor 56 outputs an electrical signal corresponding to the voltage signal in the predetermined frequency band including the second frequency to the control circuit 41. In the element unit E1, the resistance element 54 is inserted between the AC power sources 52, 53 and the coil 51a.

[0043] The voltage monitor 58 is electrically connected to the coil 51a via the high-pass filter 57. The high-pass filter 57 allows a voltage signal in a predetermined frequency band including the first frequency to pass through. The voltage monitor 58 monitors the voltage signal in the predetermined frequency band including the first frequency that passes through the high-pass filter 57 in the voltage signal reflecting the voltage induced in the coil 51a. The voltage monitor 58 outputs an electrical signal corresponding to the voltage signal in the predetermined frequency band including the first frequency to the control circuit 41.

[0044] Next, the structure of the element unit E2 will be described.

[0045] The AC power source 53 is electrically connected to the coil 51b, and applies an AC signal (AC voltage) of a predetermined second frequency to the coil 51b. As described above, the second frequency is, for example, 20kHz. In the element unit E2, the AC signal of the second frequency is applied to the coil 51b, and the AC signal of the first frequency is not applied to the coil 51b. In the element unit E2, the resistor 54 is inserted between the AC power source 53 and the coil 51b.

[0046] The voltage monitor 56 is electrically connected to the coil 51b via the low-pass filter 55. The low-pass filter 55 allows a voltage signal in a predetermined frequency band including the second frequency to pass through. The voltage monitor 56 monitors the voltage signal in a predetermined frequency band including the second frequency that passes through the low-pass filter 55 in the voltage signal reflecting the voltage induced in the coil 51b. The voltage monitor 56 outputs an electrical signal corresponding to the voltage signal in the predetermined frequency band including the second frequency to the control circuit 41.

[0047] Next, the structure of the element unit E3 will be described.

[0048] As described above, the element unit E3 includes the coil 61a. Both ends of the coil 61a are short-circuited.

[0049] Next, the structure of the element unit E4 will be described.

[0050] The element unit E4 also has a temperature sensing element 63. The temperature sensing element 63 is arranged on the rotor 20. The temperature sensing element 63 is arranged on at least one permanent magnet 25 among the plurality of permanent magnets 25. In the present embodiment, the temperature sensing element 63 is arranged only on one permanent magnet 25. The temperature sensing element 63 is arranged to be in contact with the permanent magnet 25. The temperature sensing element 63 may also be arranged near the permanent magnet 25. In this case, the temperature sensing element 63 may also be separated from the permanent magnet 25. The resistance of the temperature sensing element 63 changes according to the temperature of the permanent magnet 25. The resistance of the temperature sensing element 63 decreases as the temperature of the permanent magnet 25 rises. The temperature sensing element 63 includes, for example, a thermistor. The temperature sensing element 63 includes, for example, an NTC thermistor. The coil 61b is electrically connected to the temperature sensing element 63. Both ends of the coil 61b are electrically connected to both ends of the temperature sensing element 63.

[0051] like Figure 5 As shown in (a) and (b) of FIG. 1 , the coils 51a, 51b, 61a, and 61b include a magnetic substrate MS and a coil conductor CC. Figure 5 (a) is the top view of the coil. Figure 5 (b) is a diagram showing a cross-sectional structure of a coil.

[0052] The magnetic substrate MS is a plate-like component made of a magnetic body. The magnetic substrate MS is made of, for example, ferrite. The planar shape of the magnetic substrate MS can be circular or polygonal. The coil conductor CC is arranged on the magnetic substrate MS. The coil conductor CC is spirally shaped when viewed from above. That is, the coil conductor CC is spirally wound on the magnetic substrate MS. In the present embodiment, the coil conductor CC is wound into two layers. For example, the coil conductor CC is wound from the outside to the inside in the first layer, and then is wound from the inside to the outside in the second layer. The coil conductor CC is made of, for example, an insulating coated wire. The coil conductor CC can be wound into a circular ring or a polygonal ring.

[0053] Each coil 51a, 51b is arranged on the stator 10 in such a manner that the coil axis CA is along the rotation axis direction DA of the rotor 20. Each coil 51a, 51b is arranged on the stator 10 in such a manner that the magnetic substrate MS is located between the stator 10 and the coil conductor CC. Each coil 61a, 61b is arranged on the rotor 20 in such a manner that the coil axis CA is along the rotation axis direction DA of the rotor 20. Each coil 61a, 61b is arranged on the rotor 20 in such a manner that the magnetic substrate MS is located between the rotor 20 and the coil conductor CC. The magnetic substrate MS reduces the influence of metal parts located near each coil 51a, 51b, 61a, 61b.

[0054] When the coils 51a, 51b and the coils 61a, 61b are closely opposed to each other, the corresponding coil conductors CC do not need to be opposed in the rotation axis direction DA as a whole. That is, when viewed from the rotation axis direction DA, the corresponding coil conductors CC do not need to overlap in their entirety. For example, when the coils 51a, 51b and the coils 61a, 61b are closely opposed to each other, it is sufficient that a portion of the corresponding coil conductors CC overlap when viewed from the rotation axis direction DA.

[0055] The coil 51a of the element unit E1 generates a magnetic flux corresponding to the AC voltage applied from the AC power supplies 52 and 53. The coil 51b of the element unit E2 generates a magnetic flux corresponding to the AC voltage applied from the AC power supply 53.

[0056] When the rotor 20 rotates and the coil 51a and the coil 61a are close to each other, the magnetic flux generated in the coil 51a passes through the coil 61a. When the magnetic flux generated in the coil 51a passes through the coil 61a, power corresponding to the magnetic flux passing through the coil 61a is generated in the coil 61a. That is, the coil 51a excites the coil 61a, and power is supplied to the coil 61a.

[0057] When the rotor 20 rotates and the coil 51b and the coil 61a are close to each other, the magnetic flux generated in the coil 51b passes through the coil 61a. When the magnetic flux generated in the coil 51b passes through the coil 61a, power corresponding to the magnetic flux passing through the coil 61a is generated in the coil 61a. That is, the coil 51b excites the coil 61a, and power is supplied to the coil 61a.

[0058] Since both ends of coil 61a are short-circuited, if coil 61a and coil 51a are close to each other, the magnetic flux generated in coil 51a changes. Therefore, the voltage generated in coil 51a changes. That is, coil 51a induces a voltage corresponding to the relative position with coil 61a. If coil 61a and coil 51a are close to each other, the voltage generated in coil 51a decreases. If coil 61a is away from coil 51a, the voltage generated in coil 51a increases.

[0059] If the coil 61a and the coil 51b are close to each other, the magnetic flux generated in the coil 51b changes. Therefore, the voltage generated in the coil 51b changes. That is, the coil 51b induces a voltage corresponding to the relative position with the coil 61a. If the coil 61a and the coil 51b are close to each other, the voltage generated in the coil 51b decreases. If the coil 61a is away from the coil 51b, the voltage generated in the coil 51a increases.

[0060] exist Figure 6 (a) and (b) show an example of changes in the voltage amplitude of each coil 51a, 51b. Figure 6 (a) is a graph showing changes in voltage amplitude in the coil 51a of the element unit E1. Figure 6 (b) is a graph showing changes in voltage amplitude in the coil 51b of the element unit E2.

[0061] As described above, the voltage amplitude in each coil 51a, 51b changes according to the relative position of each coil 51a, 51b and coil 61a. The moment when the voltage amplitude decreases is the moment when each coil 51a, 51b and coil 61a are close to each other. The difference between the phase of the change of the voltage amplitude in coil 51a and the phase of the change of the voltage amplitude in coil 51b roughly corresponds to the above-mentioned first angle. Figure 6 In (a) and (b), the envelope of each voltage amplitude is represented by a dotted line.

[0062] In each element unit E1, E2, the voltage monitor 56 monitors the voltage signal input through the low-pass filter 55. That is, the voltage monitor 56 monitors the voltage signal in the prescribed frequency band domain including the second frequency. This voltage signal is a signal reflecting the voltage induced by the corresponding coils 51a, 51b. The change in the voltage monitored by the voltage monitor 56 corresponds to the change in the relative position of the coils 51a, 51b and the coil 61a, that is, the change in the rotation angle position of the rotor 20. Therefore, the electrical signal output from the voltage monitor 56, that is, the output signal of the voltage monitor 56 contains position information about the rotation angle position of the rotor 20. Each element unit E1, E2 outputs an electrical signal corresponding to the voltage signal in the prescribed frequency band domain including the second frequency in the voltage signal reflecting the voltage induced by the corresponding coils 51a, 51b as the above-mentioned position information.

[0063] The electric signal output from each voltage monitor 56 is input to the control circuit 41. The control circuit 41 calculates the rotation state of the rotor 20 based on the electric signal output from each voltage monitor 56. The rotation state of the rotor 20 includes, for example, the rotation direction of the rotor 20 and the rotation angle position of the rotor 20. The rotation direction of the rotor 20 is calculated based on, for example, the delay and advance of the phase of the change in the voltage amplitude in the coil 51b relative to the phase of the change in the voltage amplitude in the coil 51a. The rotation angle position of the rotor 20 is calculated based on the change in the voltage amplitude in each coil 51a, 51b, that is, the timing of the voltage amplitude reduction in each coil 51a, 51b.

[0064] A magnetic flux corresponding to the AC voltage applied from the AC power supplies 52 and 53 is generated in the coil 51a of the element unit E1. When the rotor 20 rotates and the coil 51a of the element unit E1 and the coil 61b of the element unit E4 are close to each other, the magnetic flux generated in the coil 51a passes through the coil 61b. When the magnetic flux generated in the coil 51a passes through the coil 61b, electric power corresponding to the magnetic flux passing through the coil 61b is generated in the coil 61b. That is, the coil 51a excites the coil 61b, and electric power is supplied to the coil 61b.

[0065] The resistance of the temperature sensing element 63 changes according to the temperature of the permanent magnet 25. The magnetic flux generated in the coil 51a changes according to the change in the resistance of the temperature sensing element 63. Therefore, the voltage generated in the coil 51a changes. That is, the coil 51a induces a voltage by the coil 61b being close to each other. If the temperature of the permanent magnet 25 rises and the resistance of the temperature sensing element 63 decreases, the voltage generated in the coil 51a decreases. If the temperature of the permanent magnet 25 drops and the resistance of the temperature sensing element 63 increases, the voltage generated in the coil 51a increases.

[0066] exist Figure 7 (a) and Figure 7(b) shows an example of the voltage amplitude of the coil 51a. Figure 7 (a) is a graph showing the voltage amplitude of the coil 51a when the temperature of the permanent magnet 25 is low. Figure 7 (b) is a graph showing the voltage amplitude of the coil 51a when the temperature of the permanent magnet 25 is high.

[0067] As described above, the voltage amplitude in the coil 51a changes according to the temperature of the permanent magnet 25. When the temperature of the permanent magnet 25 is low, the voltage amplitude in the coil 51a is larger than when the temperature of the permanent magnet 25 is high.

[0068] The voltage monitor 58 monitors the voltage signal input through the high-pass filter 57. That is, the voltage monitor 58 monitors the voltage signal in the predetermined frequency band including the first frequency. This voltage signal is a signal reflecting the voltage induced in the coil 51a. The voltage monitor 58 is an element that outputs an electrical signal corresponding to the voltage induced in the coil 51a of the element unit E1.

[0069] The change in the voltage monitored by the voltage monitor 58 corresponds to the change in the resistance of the temperature sensing element 63, that is, the change in the temperature of the permanent magnet 25. Therefore, the electrical signal output from the voltage monitor 58, that is, the output signal of the voltage monitor 58, contains temperature information about the temperature of the permanent magnet 25. The element unit E1 outputs an electrical signal corresponding to the voltage signal in the predetermined frequency band including the first frequency among the voltage signals reflecting the voltage induced by the coil 51a as the above-mentioned temperature information. As a result, the information about the temperature of the permanent magnet 25 is transmitted wirelessly between the element unit E1 and the element unit E4.

[0070] The electric signal output from the voltage monitor 58 is input to the control circuit 41. The control circuit 41 controls the driving state of the rotating electric machine MT based on the electric signal output from the voltage monitor 58. For example, the control circuit 41 controls the driving state of the rotating electric machine MT as follows. In the case where the control circuit 41 determines that the electric signal output from the voltage monitor 58 indicates that the temperature of the permanent magnet 25 has risen to a prescribed first threshold value, the control circuit 41 controls the supply of electric power to limit the rotation speed of the rotating electric machine MT. In the case where the control circuit 41 determines that the electric signal output from the voltage monitor 58 indicates that the temperature of the permanent magnet 25 has dropped to a prescribed second threshold value, the control circuit 41 controls the supply of electric power to release the restriction on the rotation speed of the rotating electric machine MT. In this case, the second threshold value is smaller than, for example, the first threshold value.

[0071] The control circuit 41 may also control the driving state of the rotating electrical machine MT as follows. That is, the control circuit 41 may also control, for example, the driving frequency input to the rotating electrical machine MT. When the control circuit 41 determines that the electrical signal output from the voltage monitor 58 indicates that the temperature of the permanent magnet 25 has risen to a predetermined first threshold value, the control circuit 41 controls the driving frequency to decrease so as to limit the rotation speed of the rotating electrical machine MT. When the control circuit 41 determines that the electrical signal output from the voltage monitor 58 indicates that the temperature of the permanent magnet 25 has dropped to a predetermined second threshold value, the control circuit 41 controls the driving frequency to increase so as to release the restriction on the rotation speed of the rotating electrical machine MT. In this case, the second threshold value is also smaller than, for example, the first threshold value.

[0072] As described above, in this embodiment, the number of coils 51a and 51b included in the element unit E1 and the element unit E2 is different from the number of coils 61a included in the element unit E3. The coils 51a and 51b and the coil 61a are respectively arranged on the stator 10 and the rotor 20 so as to be close to each other and face each other when the rotor 20 is at a predetermined rotation angle position. The coils 51a and 51b induce voltages according to their relative positions with the coil 61a. Therefore, according to this embodiment, by detecting the voltages of the coils 51a and 51b, the rotation angle position of the rotor 20 can be detected.

[0073] In the rotary electric machine MT, the coils 51 a and 51 b of the element units E1 and E2 and the coil 61 a of the element unit E3 contribute to the detection of the rotational angle position of the rotor 20 .

[0074] The coils 51a, 51b and the coil 61a are arranged on the stator 10 and the rotor 20 respectively so that the coil axes CA are along the rotation axis direction DA of the rotor 20 and the rotor 20 is close to each other and faces each other when the rotor 20 is at a predetermined rotation angle position. Therefore, the rotary electric machine MT is unlikely to be enlarged.

[0075] In the rotary electric machine MT, the coils 51 a , 51 b and the coil 61 a each have a coil conductor CC having a spiral shape in a plan view.

[0076] Therefore, when the coils 51a, 51b and the coil 61a are closely opposed to each other, the magnetic coupling between the coils 51a, 51b and the coil 61a increases. As a result, the rotary electric machine MT improves the detection accuracy of the rotation angle position of the rotor 20.

[0077] In the rotary electric machine MT, the element unit E4 includes a coil 61 b ​​and a temperature sensing element 63 .

[0078] In the rotating electrical machine MT, the coil 51a excites the coil 61b by the coil 51a and the coil 61b being close to each other, so that power is supplied to the coil 61b. The resistance of the temperature sensing element 63 electrically connected to the coil 61b changes according to the temperature of the permanent magnet 25. The voltage generated in the coil 51a changes according to the change in the resistance of the temperature sensing element 63. The voltage monitor 58 outputs an electrical signal corresponding to the voltage induced in the coil 51a. Therefore, the electrical signal output from the voltage monitor 58 changes according to the temperature of the permanent magnet 25. As a result, even when the temperature sensing element 63 is arranged on the rotor 20, the rotating electrical machine MT appropriately and simply outputs temperature information about the temperature of the permanent magnet 25.

[0079] In the rotary electric machine MT, the coil 51 a of the element unit E1 and the coil 61 b ​​of the element unit E4 contribute to the detection of the temperature of the permanent magnet 25 .

[0080] In the rotating electrical machine MT as well, the coil 61 b ​​has a coil conductor CC that is spiral in a plan view.

[0081] Therefore, when the coil 51a and the coil 61b are closely opposed to each other, the magnetic coupling between the coil 51a and the coil 61b increases. As a result, the rotary electric machine MT outputs temperature information on the temperature of the permanent magnet 25 more appropriately.

[0082] like Figure 3 As shown in (c), the element unit E4 may also include a capacitance component 65. The capacitance component 65 is arranged on the rotor 20. The coil 61b and the capacitance component 65 constitute an LC resonant circuit. The capacitance component 65 is inserted in parallel with the coil 61b, for example. The capacitance component 65 may be composed of electronic parts such as capacitors, or may be composed of parasitic capacitance of the coil 61b.

[0083] The structure in which the element unit E4 includes the capacitance component 65 can more sensitively detect the change of the temperature sensing element 63 .

[0084] Although the embodiment and the modifications of the present invention have been described above, the present invention is not limited to the embodiment and the modifications, and various changes may be made to the embodiment without departing from the scope of the present invention.

[0085] The rotating electrical machine MT may not include the element unit E4. In this case, the element unit E1 may not include the AC power supply 52, the high-pass filter 57, and the voltage monitor 58. Even when the rotating electrical machine MT does not include the element unit E4, the rotation angle position of the rotor 20 can be detected in the rotating electrical machine MT.

[0086] The number of element units E2 may also be multiple. In this case, Figure 8As shown in (a) and (b) of FIG. 1 , a plurality of coils 51 b are arranged on the stator 10 . Figure 8 (a) and (b) are schematic diagrams showing another example of the position of the coil included in each element unit.

[0087] exist Figure 8 In the structure shown in (a), one element unit E1 and three element units E2 are arranged in the rotating electrical machine MT. The rotating electrical machine MT includes one coil 51a and three coils 51b. Even in this case, Figure 8 As shown in (b) of FIG. 1 , the rotary electric machine MT also includes one coil 61 a and one coil 61 b ​​.

[0088] The number of element units E2 is not limited to three. Each coil 51a, 51b is located at a predetermined third angle interval at the rotation angle of the rotor 20. Figure 8 In the structure shown in (a), the third angle is approximately 90°. The plurality of coils 51a and 51b are provided on the stator 10 at substantially equal angular intervals.

[0089] exist Fig. 9 (a), (b), (c), and (d) show another example of the change in the voltage amplitude of each coil 51a, 51b. Fig. 9 (a) is a graph showing changes in voltage amplitude in the coil 51a of the element unit E1. Fig. 9 (b) to (d) are line graphs showing changes in the voltage amplitude in the coil 51b of the element unit E2. Fig. 9 In (a), (b), (c) and (d), the envelope of each voltage amplitude is also represented by a dotted line.

[0090] As described above, the rotational angle position of the rotor 20 is calculated based on the timing at which the voltage amplitude in each coil 51a, 51b decreases. Therefore, as the number of element units E2 increases, the detection accuracy of the rotational angle position of the rotor 20 improves.

[0091] The number of coils 61a included in the element unit E3 may be greater than the number of coils 51a and 51b included in the element unit E1 and the element unit E2. Even in this case, in the rotary electric machine MT, the rotation angle position of the rotor 20 can be detected while suppressing an increase in size.

Claims

1. A rotating electrical machine comprising: stator; A rotor configured with permanent magnets; A first number of first coils are arranged on the stator in a manner such that the coil axes are along the direction of the rotation axis of the rotor; as well as a second number of second coils different from the first number, which are arranged on the rotor in such a manner that the coil axes are along the direction of the rotation axis of the rotor, The first coil and the second coil are respectively arranged on the stator and the rotor so as to be close to each other and face each other when the rotor is at a predetermined rotation angle position. The first coil is configured to induce a voltage according to a relative position with the second coil. The rotating electrical machine further comprises: a temperature sensing element disposed on the rotor and configured such that a resistance thereof changes according to a temperature of the permanent magnet; A third coil, which is disposed on the rotor and electrically connected to the temperature sensing element; as well as An element is configured to output an electrical signal corresponding to the voltage induced in the first coil.

2. The rotating electrical machine according to claim 1, wherein: The first and second coils each have a coil conductor that is spiral in plan view.

3. The rotating electrical machine according to claim 1, wherein: The rotating electrical machine further includes a capacitance component which forms an LC resonance circuit with the third coil.

4. The rotating electrical machine according to claim 3, wherein: The third coil has a coil conductor that is spiral in plan view.

5. The rotating electrical machine according to claim 1, wherein: The third coil has a coil conductor that is spiral in plan view.

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