Rotor, rotary electric machine, automobile, and rotor manufacturing method

Abstract

This rotor comprises magnets, a core, a shaft, and a temperature information transmission device. The core is rotated while holding the magnets. The shaft is disposed on the rotation axis of the core. The temperature information transmission device includes a temperature-sensitive unit and coils. The temperature-sensitive unit detects temperature. The coils output information about the temperature detected by the temperature-sensitive unit. The temperature-sensitive unit is installed closer to the magnets than the coils. The coils are disposed on the shaft.

Description

Rotor, Rotating Electrical Machine, Automobile, and Method for Manufacturing Rotor 【0001】 The present disclosure relates to a rotor, a rotating electrical machine, an automobile, and a method for manufacturing a rotor. This application claims priority based on Japanese Application No. 2024-218751 filed on December 20, 2024, and incorporates all the descriptions described in the above Japanese application. 【0002】 A rotor provided with a temperature information transmission device is known (see, for example, Patent Document 1). The temperature information transmission device detects temperature and transmits information on the detected temperature. This temperature information transmission device includes a temperature sensing portion that detects temperature and a coil that outputs information on the temperature detected by the temperature sensing portion. 【0003】 Japanese Unexamined Patent Application Publication No. 2021-39019 【0004】 In a rotating electrical machine including a rotor and a stator, the temperature inside the rotating electrical machine may rise due to the operation of the rotor rotating inside the rotating electrical machine. The temperature change inside the rotating electrical machine may affect the operation of the rotor. For example, the magnetic force of a magnet may change according to a change in the temperature of the magnet. Therefore, it is conceivable to acquire temperature information in the rotor. 【0005】 However, the information output from the coil of the temperature information transmission device may be affected by electromagnetic noise according to the arrangement of the coil. Furthermore, the coil may also be damaged by centrifugal force according to the arrangement of the coil. 【0006】 One aspect of the present disclosure aims to provide a rotor in which the influence of electromagnetic noise in the temperature information transmission device is reduced and the risk of damage is also reduced. Another aspect of the present disclosure aims to provide a rotating electrical machine provided with the above-described rotor. Still another aspect of the present disclosure aims to provide an automobile provided with the above-described rotating electrical machine. Still another aspect of the present disclosure aims to provide a method for manufacturing a rotor in which the influence of electromagnetic noise in the temperature information transmission device is reduced and the risk of damage is also reduced. 【0007】A rotor according to one embodiment comprises a magnet, a core, a shaft, and a temperature information transmitting device. The core rotates while holding the magnet. The shaft is mounted on the rotation axis of the core. The temperature information transmitting device includes a temperature sensing element and a coil. The temperature sensing element detects temperature. The coil outputs temperature information detected by the temperature sensing element. The temperature sensing element is positioned closer to the magnet than the coil. The coil is mounted on the shaft. 【0008】 In one of the above embodiments, the temperature-sensing element is positioned closer to the magnet than the coil, and the coil is mounted on the shaft. In this case, the temperature of the magnet is detected by the temperature-sensing element, while the influence of electromagnetic noise from the magnet on the coil is reduced. Furthermore, the centrifugal force applied to the coil is reduced, thereby reducing the risk of coil damage. 【0009】 In one of the above embodiments, the core may have a gap extending in the direction of the axis of rotation. The magnet may be inserted into the gap. The temperature-sensing element may be in contact with the surface of the magnet. In this case, the temperature of the magnet can be detected more accurately by the temperature-sensing element. 【0010】 In one of the above embodiments, the rotor may further include a positioning member. The positioning member may position the temperature-sensing part so that it contacts the surface of the magnet. The temperature-sensing part may be in contact with the magnet inside the gap. The positioning member may press the temperature-sensing part toward the magnet. In this case, the contact area between the temperature-sensing part and the magnet is ensured, and the temperature of the magnet is detected more accurately. 【0011】 In one of the above embodiments, the coil axis of the coil may extend in a direction perpendicular to the axis of rotation. In this case, the influence of rotor misalignment on the temperature information output from the coil is reduced. 【0012】In one of the above embodiments, the rotor may further include a fixing member for securing the coil to the shaft. The fixing member may include a ring portion and a support portion. The ring portion may have a through hole into which the shaft is inserted and may be fixed to the shaft. The support portion may be connected to the ring portion and support the coil. In this case, the coil is more easily and securely fixed to the shaft. 【0013】 Another embodiment of a rotating electric machine comprises a stator, the rotor, and a temperature information receiving device. The temperature information receiving device is provided on the stator and includes a coil that is magnetically coupled to the coil of the rotor. 【0014】 In another embodiment described above, the temperature information receiving device includes a coil that is magnetically coupled to the rotor coil. Therefore, the temperature information of the rotor magnet is acquired. 【0015】 Another embodiment of the automobile is equipped with the above-mentioned rotating electric machine. Thus, an automobile having the above-mentioned rotating electric machine is provided. By equipping the automobile with the above-mentioned rotor electric machine, the operating time of the cooling system for temperature control of the rotating electric machine can be appropriately controlled. As a result, the operating time of the cooling system can be reduced. Therefore, the power consumption of the automobile can be reduced. 【0016】 In yet another embodiment of the rotor manufacturing method, a temperature information transmitting device is attached to a core that rotates around a shaft as its axis of rotation while holding a magnet. The temperature information transmitting device includes a temperature sensing unit that detects temperature and a coil that outputs temperature information detected by the temperature sensing unit. The above manufacturing method is characterized by placing the temperature sensing unit closer to the magnet than the coil and installing the coil on the shaft. 【0017】In yet another embodiment described above, the manufacturing method includes placing a temperature-sensing element closer to the magnet than the coil, and installing the coil on the shaft. In this case, in the manufactured rotor, the temperature of the magnet is detected by the temperature-sensing element, while the influence of electromagnetic noise from the magnet on the coil is reduced. Furthermore, the centrifugal force applied to the coil is reduced, and the risk of coil damage is reduced. Therefore, a rotor is provided in which the influence of electromagnetic noise is reduced and the risk of damage is also reduced. 【0018】 In yet another embodiment described above, the temperature sensing element may be installed so as to be in contact with the surface of the magnet when the magnet is located inside a gap that extends in the direction of the rotation axis. In this case, a rotor is provided in which the temperature of the magnet is detected more accurately by the temperature sensing element. 【0019】 In yet another embodiment described above, the temperature sensing element may be positioned within the gap so as to be pressed toward the magnet by a positioning member. In this case, a rotor is provided in which the temperature of the magnet is detected more accurately by the temperature sensing element. 【0020】 In yet another embodiment described above, the coil may be installed on a shaft such that the coil axis extends in a direction perpendicular to the axis of rotation. In this case, a rotor is provided that is designed to reduce the effect of rotor misalignment on the temperature information output from the coil. 【0021】 In yet another embodiment described above, when installing the coil, the ring portion of the fixing member that secures the coil may be fixed to the shaft by inserting the shaft into the through hole of the ring portion of the fixing member that secures the coil. The coil may be supported by a support portion connected to the ring portion. In this case, a rotor is provided having a coil that is more securely fixed to the shaft. 【0022】 In yet another embodiment described above, the method for manufacturing the rotor may further include electrically connecting the temperature-sensing element and the coil of the temperature-sensing section using circuit board wiring or wire wrapping. In this case, the temperature information transmitting device can be easily positioned so as to ensure the temperature detection accuracy of the magnet. 【0023】 According to one aspect of this disclosure, a rotor is provided in which the influence of electromagnetic noise in a temperature information transmitting device is reduced and the risk of damage is also reduced. Another aspect of this disclosure provides a rotating electric machine equipped with the rotor described above. Yet another aspect of this disclosure provides an automobile equipped with the rotating electric machine described above. Yet another aspect of this disclosure provides a method for manufacturing a rotor in which the influence of electromagnetic noise in a temperature information transmitting device is reduced and the risk of damage is also reduced. 【0024】 Figure 1 is a schematic diagram showing the configuration of a rotating electric machine according to one embodiment. Figure 2 is a partial perspective view showing an example of the configuration of the rotor and temperature detection device. Figure 3 is a perspective view showing a fixing member for fixing the transmitting coil. Figure 4 is a partial cross-sectional view showing the arrangement of the temperature sensing part in a modified example of this embodiment. Figure 5 is a partial cross-sectional view showing the arrangement of the temperature sensing part in a modified example of this embodiment. Figure 6 is a schematic diagram showing the configuration of an electric vehicle. Figure 7 is a partial perspective view showing the configuration of the rotor in a modified example of this embodiment. Figure 8 is a perspective view showing a fixing member in a modified example of this embodiment. Figure 9A is a diagram showing the positional relationship between the transmitting coil and the receiving coil. Figure 9B is a diagram showing the relationship between the misalignment and the coupling coefficient of the coils. Figure 10A is a diagram showing the positional relationship between the transmitting coil and the receiving coil. Figure 10B is a diagram showing the relationship between the misalignment and the coupling coefficient of the coils. 【0025】 Embodiments of the present invention will be described in detail below with reference to the attached drawings. In this description, the same reference numerals will be used for the same element or element having the same function, and redundant explanations will be omitted. 【0026】 The configuration of the rotating electric machine MT according to this embodiment will be described with reference to Figures 1 to 3. Figure 1 is a schematic diagram showing the configuration of the rotating electric machine according to this embodiment. Figure 2 is a partial perspective view showing the configuration of the rotor. 【0027】As shown in Figure 1, the rotating electric machine MT is, for example, a motor. The motor includes, for example, an IPM motor or an SPM motor. The motor may also be a wound-field motor. In the following, unless otherwise specified, the case in which the rotating electric machine MT is an IPM motor will be described as an example. As shown in Figure 1, the rotating electric machine MT comprises a stator 10 and a rotor 20. The rotor 20 is located inside the stator 10. 【0028】 The rotating electric machine MT is further equipped with a temperature detection device 30. The temperature detection device 30 detects the internal temperature of the rotating electric machine MT. The temperature detection device 30 detects the temperature of a part of the rotor 20. To achieve this function, the temperature detection device 30 includes a temperature information transmitting device 50 and a temperature information receiving device 60. The temperature information transmitting device 50 detects the internal temperature of the rotating electric machine MT and transmits temperature information related to the detected temperature. The temperature information receiving device 60 receives the temperature information transmitted from the temperature information transmitting device 50. The temperature information transmitting device 50 is installed on the rotor 20. The temperature information receiving device 60 is installed on the stator 10. 【0029】The stator 10 includes a cylindrical stator core (not shown) arranged to surround the outer circumference of the rotor 20, and a plurality of stator coils 11. The stator 10 may further include a case that surrounds the stator core, the plurality of stator coils 11, and the rotor 20. A uniform width air gap is provided between the stator 10 and the rotor 20. "Uniform width" does not necessarily mean that the width of each air gap between the stator 10 and the rotor 20 is uniform. The width of each air gap between the stator 10 and the rotor 20 may be considered uniform even if there are slight differences, manufacturing errors, or measurement errors within a preset range. If there are slight differences within a preset range, for example, the width of each air gap between the stator 10 and the rotor 20 may be considered uniform if it is within ±10% of the average width of all air gaps. The stator core holds the plurality of stator coils 11. Each stator coil 11 is positioned on the inner circumference side of the stator core. The multiple stator coils 11 are arranged at equal angular intervals with respect to the rotation axis of the rotor 20. 【0030】 The rotor 20 includes a shaft 21, a rotor core 23, and a plurality of magnets 25. The rotor core 23 holds the magnets 25. The temperature detection device 30 detects the temperature of the magnets 25, for example, as the internal temperature of the rotating electric machine MT. The rotor core 23 rotates while holding the magnets 25. The shaft 21 is mounted on the rotation axis of the rotor core 23. The shaft 21 has a cylindrical shape. The rotor core 23 has a cylindrical shape. The rotor core 23 has an axial hole into which the shaft 21 is fitted. The shaft 21 and the rotor core 23 rotate integrally around the central axis of the shaft 21. 【0031】The rotor core 23 includes a pair of end faces 23a and 23b and one side. End face 23a is located closer to the temperature detection device 30. End face 23b is located on the opposite side of end face 23a in the rotation axis direction D. That is, the pair of end faces 23a and 23b are perpendicular to the rotation axis direction D and face opposite directions to each other. The statement that "the pair of end faces 23a and 23b are perpendicular to the rotation axis direction D" does not necessarily mean that the pair of end faces 23a and 23b are perpendicular to the rotation axis direction D. The pair of end faces 23a and 23b may be considered perpendicular to the rotation axis direction D even if there are slight differences, manufacturing errors, or measurement errors within a preset range. If there are slight differences within a preset range, for example, if the angle between the pair of end faces 23a and 23b and the rotation axis direction D is within ±1 degree from the perpendicular, the pair of end faces 23a and 23b may be considered perpendicular to the rotation axis direction D. 【0032】 The rotor core 23 is constructed by stacking multiple steel plates in the direction of rotation axis D. The rotor core 23 includes multiple steel plates stacked in the direction of rotation axis D. The steel plates are magnetic. The steel plates may be, for example, silicon steel plates. In the example shown in this embodiment, the steel plate located closest to the temperature detection device 30 among the multiple steel plates includes an end face 23a as its surface. The rotor core 23 has a gap S. The gap S extends in the direction of rotation axis D. The gap S has a hollow column shape. For example, the cross-section of the gap S in the direction perpendicular to the direction of rotation axis D has the same shape in the direction of rotation axis D. The gap S is connected to the end face 23a. 【0033】 The magnet 25 has, for example, a columnar shape. "Columnar shape" means a shape in which the length in a given direction is longer than the length in other directions. A columnar shape includes, for example, a shape whose cross-section is enclosed by straight lines, a shape enclosed by curves, and a shape enclosed by both straight lines and curves. A columnar shape also includes, for example, a shape whose cross-section is circular, polygonal, or C-shaped. 【0034】Each magnet 25 is positioned on the rotor core 23 such that its longitudinal direction is parallel to the central axis of the shaft 21. The phrase "the longitudinal direction of the magnet 25 is parallel to the central axis of the shaft 21" does not necessarily mean that the longitudinal direction of the magnet 25 is parallel to the central axis of the shaft 21. The longitudinal direction of the magnet 25 may be considered parallel to the central axis of the shaft 21 even if there are slight differences, manufacturing errors, or measurement errors within a predetermined range. If there are slight differences within a predetermined range, for example, if the angle between the longitudinal direction of the magnet 25 and the central axis of the shaft 21 is within ±2 degrees, the longitudinal direction of the magnet 25 may be considered parallel to the central axis of the shaft 21. 【0035】 The magnet 25 is positioned on the rotor core 23. The magnet 25 is inserted into the gap S with its longitudinal direction corresponding to the rotation axis direction D. In the example shown in this embodiment, the entire magnet 25 is located inside the gap S. The magnet 25 has a pair of end faces 25a and 25b, a pair of side faces 25c, and a pair of side faces 25d. End face 25a is located closer to the temperature detection device 30. End face 25b is located on the opposite side of end face 25a in the rotation axis direction D. The pair of side faces 25c and the pair of side faces 25d connect end face 25a and end face 25b, respectively. The pair of side faces 25c are located on opposite sides of each other in the direction intersecting the rotation axis direction D. The pair of side faces 25d are located on opposite sides of each other in the direction intersecting the rotation axis direction D. The pair of side faces 25d connect the pair of side faces 25c. For example, the area of ​​each side face 25d is larger than the area of ​​the side face 25c. 【0036】The pair of end faces 25a and 25b are perpendicular to the rotation axis direction D and face in opposite directions. The statement that "the pair of end faces 25a and 25b are perpendicular to the rotation axis direction D" does not necessarily mean that the pair of end faces 25a and 25b are perpendicular to the rotation axis direction D. The pair of end faces 25a and 25b may be considered perpendicular to the rotation axis direction D even if there are slight differences, manufacturing errors, or measurement errors within a predetermined range. If there are slight differences within a predetermined range, for example, the pair of end faces 25a and 25b may be considered perpendicular to the rotation axis direction D if the angle between the pair of end faces 25a and 25b and the rotation axis direction D is within ±2 degrees from the perpendicular. 【0037】 The central axis of the shaft 21 is the rotation axis of the rotor 20. The direction in which the rotation axis of the rotor 20 extends is the rotation axis direction D of the rotor 20. One magnet may constitute one pole, or multiple magnets may constitute one pole. When one magnet constitutes one pole, the multiple magnets 25 are arranged at equal angular intervals with respect to the rotation axis of the rotor 20. "Equal angular intervals" does not necessarily mean that each angular interval is the same. The angular intervals may be considered equal even if there are slight differences, manufacturing errors, or measurement errors within a predetermined range. If there are slight differences within a predetermined range, for example, if each angular interval of the magnets 25 with respect to the rotation axis of the rotor 20 is within ±10% of the average angular interval of all angular intervals, then the angular intervals of the magnets 25 with respect to the rotation axis of the rotor 20 may be considered equal. 【0038】 If the rotating electric machine MT is an IPM motor, the multiple magnets 25 are arranged inside the rotor core 23. If the rotating electric machine MT is an SPM motor, the multiple magnets 25 are arranged on the surface of the rotor core 23. The magnets 25 are, for example, permanent magnets. The magnets 25 include rare earth magnets. The magnets 25 include, for example, neodymium sintered magnets. Each magnet 25 may include a sintered magnet other than a rare earth magnet, or a magnet other than a sintered magnet. The magnets other than sintered magnets include, for example, bonded magnets or hot-worked magnets. 【0039】The rotating electrical machine MT is connected to the control circuit 41. The control circuit 41 is connected to the power source 43. The control circuit 41 adjusts the drive current from the power source 43 and supplies a three-phase alternating current to each stator coil 11. The control circuit 41 controls the value of the three-phase alternating current supplied to each stator coil 11. The control circuit 41 includes, for example, an inverter circuit. When a three-phase alternating current is supplied to each stator coil 11, each stator coil 11 forms a rotating magnetic field that rotates the rotor 20. The power source 43 includes, for example, an electrical energy storage device. The electrical energy storage device includes, for example, a secondary battery or a capacitor. 【0040】 Next, referring to FIGS. 2 and 3, the configuration of the rotor 20 will be described in more detail. FIG. 2 is a partial perspective view showing an example of the rotor and the temperature detection device. 【0041】 The temperature information transmission device 50 is provided on the rotor 20 and includes a transmission coil 51, a temperature sensing portion 52, and a wiring 53. The temperature sensing portion 52 detects the temperature. The transmission coil 51 outputs information on the temperature detected by the temperature sensing portion 52. 【0042】 The temperature information reception device 60 is provided on the stator 10 and includes a reception coil 61. The reception coil 61 receives the information output from the transmission coil 51. The temperature information reception device 60 is provided, for example, on the stator core. In the example shown in this embodiment, the temperature detection device 30 includes one temperature information reception device 60 and one temperature information transmission device 50. 【0043】The transmitting coil 51 and the receiving coil 61 are magnetically coupled to each other. The transmitting coil 51 and the receiving coil 61 are positioned so as to face each other in a direction parallel to the rotation axis of the rotor 20 when the rotor 20 is at a predetermined rotational angle position. "A direction parallel to the rotation axis of the rotor 20" does not necessarily mean only a direction parallel to the rotation axis of the rotor 20. Even if a slight difference within a predetermined range, manufacturing error, or measurement error is included, it may still be considered a direction parallel to the rotation axis of the rotor 20. If a slight difference within a predetermined range is included, for example, if the angle with the rotation axis of the rotor 20 is within ±2 degrees, it may be considered a direction parallel to the rotation axis of the rotor 20. 【0044】 The transmitting coil 51 is installed on the shaft 21. In the example shown in this embodiment, the coil axis of the transmitting coil 51 extends in a direction perpendicular to the rotation axis direction D. In other words, the coil axis of the transmitting coil 51 extends in a direction perpendicular to the extension direction of the shaft 21. The direction perpendicular to the extension direction of the shaft 21 is, for example, the radial direction of the shaft 21. The transmitting coil 51 and the receiving coil 61 face each other in a direction perpendicular to the rotation axis direction D when the rotation angle of the rotor 20 is a predetermined angle. 【0045】 In the example shown in this embodiment, as shown in Figure 3, the rotor 20 further includes a fixing member 70. The fixing member 70 is, for example, a set collar. The fixing member 70 fixes the transmitting coil 51 to the shaft 21. The fixing member 70 includes a ring portion 71 and a support portion 72. The ring portion 71 has a through hole 71a into which the shaft 21 is inserted. The ring portion 71 is fixed to the shaft 21. The support portion 72 supports the transmitting coil 51. The support portion 72 is connected to the ring portion 71. The support portion 72 extends from the ring portion 71 in the direction of the rotation axis D. 【0046】The support portion 72, for example, has a plate shape. The support portion 72 has a support surface 72a to which the transmission coil 51 is joined. In the example shown in this embodiment, the normal line of the support surface 72a extends in a direction orthogonal to the rotation axis of the rotor 20. For example, the reception coil 61 is provided on a support surface facing the support surface 72a in a direction orthogonal to the rotation axis direction D when the rotation angle of the rotor 20 is a predetermined angle. 【0047】 As a modification of this embodiment, the transmission coil 51 may be embedded in the shaft 21. For example, a depression is formed in the shaft 21, and the transmission coil 51 is disposed in the depression of the shaft 21 so that a part of the transmission coil 51 is exposed. 【0048】 The temperature sensing portion 52 is provided at a predetermined portion of the rotor 20. The temperature sensing portion 52 includes, for example, a temperature sensing element. In the example shown in this embodiment, the temperature sensing portion 52 is a temperature sensing element. The temperature sensing portion 52 may include members other than the temperature sensing element, such as a case for housing the temperature sensing element. In the temperature sensing portion 52, the electrical resistance changes according to the temperature of the above-described portion. The temperature sensing portion 52 may be, for example, a thermistor or a Hall element. The thermistor may be, for example, an NTC thermistor or a PCT thermistor. When the temperature sensing portion 52 is an NTC thermistor, the electrical resistance decreases as the temperature rises in the temperature sensing portion 52. 【0049】 The temperature sensing portion 52 is electrically connected to the transmission coil 51. In the example shown in this embodiment, the transmission coil 51 and the temperature sensing portion 52 are connected by wiring 53. For example, both ends of the transmission coil 51 are electrically connected to both ends of the temperature sensing portion 52 by the wiring 53, respectively. As a modification of this embodiment, a capacitor may be connected to the transmission coil 51 in parallel with the temperature sensing portion 52. In the example shown in this embodiment, the temperature sensing element of the temperature sensing portion 52 and the transmission coil 51 are electrically connected using a substrate wiring. For example, the transmission coil 51 is provided on the substrate, and both ends of the transmission coil 51 are connected to the wiring 53 by the substrate wiring, respectively. In a modification of this embodiment, the temperature sensing element of the temperature sensing portion 52 and both ends of the transmission coil 51 may be electrically connected using wire wrapping. 【0050】 The temperature sensing unit 52 is positioned closer to the magnet 25 than the transmitting coil 51. The temperature sensing unit 52 is positioned closer to the magnet 25 that is the target of temperature detection among the multiple magnets 25 included in the rotor 20 than the transmitting coil 51. In other words, the temperature sensing unit 52 is positioned closer to the gap S than the transmitting coil 51. In the example shown in this embodiment, the temperature sensing unit 52 is located on the end face 23a of the rotor core 23. 【0051】 In a modified example of this embodiment, the temperature-sensing portion 52 is in contact with the surface of the magnet 25. For example, the temperature-sensing portion 52 is provided on at least one of the multiple magnets 25. For example, as shown in Figure 4, the temperature-sensing portion 52 is in contact with the end face 25a of the magnet 25. For example, of the end face 25a and the end face 25b, at least the end face 25a is exposed from the gap S. In the modified example shown in Figure 4, the temperature-sensing portion 52 is located outside the gap S, and the temperature-sensing portion 52 is in contact with the end face 25a exposed from the gap S. 【0052】 For example, as shown in Figure 5, the temperature-sensing part 52 may be in contact with the side surface 25c of the magnet 25. In the modified example shown in Figure 5, the temperature-sensing part 52 is located inside the gap S. The temperature-sensing part 52 is in contact with the side surface 25c inside the gap S. For example, the rotor 20 further has a positioning member 75. The positioning member 75 positions the temperature-sensing part 52 so that it is in contact with the side surface 25c of the surface of the magnet 25. The positioning member 75 presses the temperature-sensing part 52 toward the magnet 25. The positioning member 75 may be, for example, a leaf spring. In this case, the leaf spring is provided between the rotor core 23 defining the gap S and the temperature-sensing part 52, and biases the temperature-sensing part 52 toward the rotor core 23. In a further modified example of this modified example, the positioning member 75 may be a resin sheet. The resin sheet may be, for example, a resin containing a foaming agent. A resin sheet is, for example, a thermally expanding sheet that expands due to heat. 【0053】The temperature information receiving device 60 has, for example, a capacitor in addition to the receiving coil 61. The receiving coil 61 and the capacitor constitute an LC resonant circuit. The transmitting coil 51, the receiving coil 61, and the capacitor may also constitute an LC resonant circuit. The receiving coil 61 is installed on the stator 10 so as to face the transmitting coil 51 in the rotation axis direction D of the rotor 20 when the rotor 20 is at a predetermined rotation angle position. 【0054】 It is preferable that the coil axis of the receiving coil 61 and the coil axis of the transmitting coil 51 coincide when the rotor 20 is at a predetermined rotational angle position, but detection accuracy is ensured as long as the misalignment between the coil axis of the receiving coil 61 and the coil axis of the transmitting coil 51 is within a predetermined range. For example, when the rotor 20 is at a predetermined rotational angle position, the misalignment between the coil axis of the receiving coil 61 and the coil axis of the transmitting coil 51 may be within 15 degrees. If the misalignment between the coil axis of the receiving coil 61 and the coil axis of the transmitting coil 51 is, for example, within 10 degrees when the rotor 20 is at a predetermined rotational angle position, the impact on detection accuracy can be further reduced. 【0055】 The receiving coil 61 is magnetically coupled to the transmitting coil 51. The receiving coil 61 is electrically connected to an AC power supply. The AC power supply may be, for example, an inverter. An AC signal of a predetermined frequency is applied to the receiving coil 61 from the AC power supply. An AC voltage is applied to the receiving coil 61 from the AC power supply. The predetermined frequency is higher than the drive frequency of the rotating electric machine MT. The predetermined frequency is, for example, 10 to 2000 times the drive frequency of the rotating electric machine MT. 【0056】A magnetic flux corresponding to the AC voltage applied from the AC power source is generated in the receiving coil 61. As the rotor 20 rotates and the receiving coil 61 and the transmitting coil 51 move closer together, the magnetic flux generated in the receiving coil 61 passes through the transmitting coil 51. When the magnetic flux generated in the receiving coil 61 passes through the transmitting coil 51, power is generated in the transmitting coil 51 corresponding to the change in magnetic flux passing through the transmitting coil 51. In other words, as the rotor 20 rotates and the receiving coil 61 and the transmitting coil 51 move closer together, the receiving coil 61 and the transmitting coil 51 become magnetically coupled. It can also be said that the receiving coil 61 excites the transmitting coil 51 and supplies power to the transmitting coil 51. 【0057】 If the electrical resistance of the temperature-sensing element 52 changes in accordance with the internal temperature of the rotating electric machine MT, the magnetic flux generated in the receiving coil 61 will change in accordance with the change in the electrical resistance of the temperature-sensing element 52. For example, the electrical resistance of the temperature-sensing element 52 changes in accordance with the temperature of the magnet 25. The current flowing through the receiving coil 61 will change in accordance with the change in the magnetic flux generated in the receiving coil 61. 【0058】 When the internal temperature of the rotating electric machine MT rises and the electrical resistance of the temperature-sensing unit 52 decreases, the magnetic flux generated in the receiving coil 61 increases. As a result, the current flowing through the receiving coil 61 increases. When the internal temperature of the rotating electric machine MT decreases and the electrical resistance of the temperature-sensing unit 52 increases, the magnetic flux generated in the receiving coil 61 decreases. As a result, the current flowing through the receiving coil 61 decreases. 【0059】 The temperature information receiving device 60 outputs an electrical signal relating to the phase of the power generated in the receiving coil 61 as temperature information of the temperature detected by the temperature sensing unit 52. The temperature information receiving device 60 may include, for example, a computing device including a CPU (Central Processing Unit), ROM (Read Only Memory), and RAM (Random Access Memory). The computing device may be, for example, a microcomputer. With this configuration, temperature information relating to the internal temperature of the rotating electric machine MT is transmitted wirelessly between the temperature information transmitting device 50 and the temperature information receiving device 60. 【0060】The electrical signal output from the temperature information receiving device 60 is input to the control circuit 41 as the temperature information. The control circuit 41 acquires the electrical signal output from the temperature detection device 30. Based on the acquired electrical signal, the control circuit 41 obtains the internal temperature of the rotating electric machine MT. In other words, in this embodiment, the control circuit 41 functions as a temperature acquisition device. 【0061】 The control circuit 41 obtains the internal temperature of the rotating electric machine MT, for example, as follows. First, the control circuit 41 refers to data showing the relationship between electrical signals acquired from the temperature detection device 30 and temperature. This data may be stored in the control circuit 41 or in an external server different from the control circuit 41. Next, the control circuit 41 obtains the temperature corresponding to the acquired electrical signal in the above data as the internal temperature of the rotating electric machine MT. 【0062】 The control circuit 41 controls the driving state of the rotating electric machine MT based on the obtained internal temperature of the rotating electric machine MT. For example, the control circuit 41 controls the driving state of the rotating electric machine MT as follows: When the control circuit 41 determines that the obtained internal temperature of the rotating electric machine MT has risen to a predetermined first threshold, the control circuit 41 controls the power supply to limit the rotational speed of the rotating electric machine MT. When the control circuit 41 determines that the obtained internal temperature of the rotating electric machine MT has fallen to a predetermined second threshold that is lower than the first threshold, the control circuit 41 controls the power supply to release the restriction on the rotational speed of the rotating electric machine MT. 【0063】 The control circuit 41 may control the driving state of the rotating electric machine MT as follows. That is, the control circuit 41 may control, for example, the driving frequency input to the rotating electric machine MT based on the obtained internal temperature of the rotating electric machine MT. When the control circuit 41 determines that the obtained internal temperature of the rotating electric machine MT has risen to a predetermined first threshold, the control circuit 41 controls the driving frequency to lower it in order to limit the rotational speed of the rotating electric machine MT. When the control circuit 41 determines that the obtained internal temperature of the rotating electric machine MT has fallen to a predetermined second threshold that is smaller than the first threshold, the control circuit 41 controls the driving frequency to raise it in order to release the limit on the rotational speed of the rotating electric machine MT. 【0064】The control circuit 41 includes, for example, a CPU (Central Processing Unit), ROM (Read Only Memory), and RAM (Random Access Memory). The control circuit 41 performs the above-mentioned tasks of obtaining the internal temperature of the rotating electric machine MT and controlling the driving state of the rotating electric machine MT by, for example, loading a program stored in ROM into RAM and executing it with the CPU. 【0065】 Next, the configuration of an electric vehicle equipped with a rotating electric motor (MT) will be described using Figure 6. As shown in Figure 6, the electric vehicle 200 includes a rotating electric motor (MT), a battery 210, a power converter 220, a gear 230, an axle 240, and wheels 250. The electric vehicle 200 operates using the driving force from the rotating electric motor (MT). 【0066】 When the electric vehicle 200 is driven by the rotating electric motor MT, the battery 210 supplies DC power to the power converter 220. The power converter 220 converts the DC power from the battery 210 into AC power and supplies the converted AC power to the rotating electric motor MT. 【0067】 When the electric vehicle 200 performs regenerative braking, the rotating electric motor MT generates alternating current (AC) power in accordance with the vehicle's kinetic energy, and this AC power is supplied to the power converter 220. The power converter 220 converts the AC power from the rotating electric motor MT into DC power and supplies the converted DC power to the battery 210. 【0068】 The rotational torque from the rotating electric motor MT is transmitted to the wheel 250 via the gear 230 and the axle 240. In a modified version of this embodiment, the rotational torque from the rotating electric motor MT may be transmitted to the wheel 250 by a different torque transmission configuration. 【0069】 In this embodiment, in the manufacturing method of the rotor 20, a temperature information transmitting device 50 is attached to the rotor core 23. The temperature sensing unit 52 is installed closer to the magnet 25 than the transmitting coil 51. The transmitting coil 51 is installed on the shaft 21. 【0070】For example, in the installation of the temperature-sensing unit 52, the temperature-sensing unit 52 is installed so as to be in contact with the surface of the magnet 25 when the magnet 25 is located inside the gap S that extends in the direction of the rotation axis. In the installation of the temperature-sensing unit 52, the temperature-sensing unit 52 is positioned inside the gap S so as to be pressed toward the magnet 25 by the positioning member 75. 【0071】 For example, in the installation of the transmitting coil 51, the transmitting coil 51 is installed on the shaft 21 such that the coil axis of the transmitting coil 51 extends in a direction perpendicular to the rotation axis. The transmitting coil 51 may also be installed on the shaft 21 such that the coil axis of the transmitting coil 51 extends in the rotation axis direction D. For example, as shown in Figure 3, the ring portion 71 is fixed to the shaft 21 by inserting the shaft 21 into the through hole 71a of the ring portion 71. The transmitting coil 51 is installed and supported by a support portion 72 connected to the ring portion 71. 【0072】 Next, the configuration of another modified example of the rotating electric machine will be described using Figures 7 and 8. This modified example differs from the embodiment described above in terms of the configuration of the temperature detection device. The differences between the embodiment described above and this modified example will be mainly described below. Figure 7 is a partial perspective view showing the configuration of the rotor of the modified example of this embodiment. Figure 8 is a perspective view showing the fixing member in the modified example of this embodiment. 【0073】 In this modified example, the rotating electric machine MT is equipped with a temperature detection device 30A instead of the temperature detection device 30. The temperature detection device 30A includes a temperature information transmitting device 50A and a temperature information receiving device 60A instead of the temperature information transmitting device 50 and the temperature information receiving device 60. The orientation of the transmitting coil 51 of the temperature information transmitting device 50A is different from that of the temperature information transmitting device 50. Similarly, the orientation of the receiving coil 61 of the temperature information receiving device 60A is different from that of the temperature information receiving device 60. 【0074】 In this modified example, the coil axis of the transmitting coil 51 extends in the direction of the rotation axis D. In other words, the coil axis of the transmitting coil 51 extends in the direction of the shaft 21. The transmitting coil 51 and the receiving coil 61 face each other in the direction of the rotation axis D when the rotation angle of the rotor 20A is a predetermined angle. 【0075】 In this modified example, the rotor 20A includes a fixing member 90 instead of a fixing member 70. The fixing member 90 is, for example, a set collar. The fixing member 90 includes a ring portion 71 and a support portion 92. The support portion 92 supports the transmitting coil 51. The support portion 92 is connected to the ring portion 71. The support portion 92 extends from the ring portion 71 in a direction perpendicular to the rotation axis direction D. 【0076】 The support portion 92 has a support surface 92a to which the transmitting coil 51 is joined. In this modified example, the normal to the support surface 92a extends in the direction of the rotation axis D of the rotor 20. For example, the receiving coil 61 is provided on a support surface facing the support surface 92a in the direction of the rotation axis D when the rotation angle of the rotor 20 is a predetermined angle. 【0077】 As explained above, the temperature sensing unit 52 is positioned closer to the magnet 25 than the transmitting coil 51, and the transmitting coil 51 is installed on the shaft 21. In this case, the temperature of the magnet 25 is detected by the temperature sensing unit 52, while the influence of electromagnetic noise from the magnet 25 on the transmitting coil 51 is reduced. Furthermore, the centrifugal force applied to the transmitting coil 51 is reduced, thereby reducing the risk of damage to the transmitting coil 51. 【0078】 The rotor core 23 may have a gap S extending in the direction of the rotation axis D. The magnet 25 is inserted into the gap S. The temperature sensing element 52 is in contact with the surface of the magnet 25. In this case, the temperature sensing element 52 can detect the temperature of the magnet 25 more accurately. 【0079】 The rotor 20 may further include a positioning member 75. The positioning member 75 may position the temperature-sensing part 52 so that it contacts the surface of the magnet 25. The temperature-sensing part 52 may be in contact with the magnet 25 inside the gap S. The positioning member 75 may press the temperature-sensing part 52 toward the magnet 25. In this case, the contact area between the temperature-sensing part 52 and the magnet 25 is ensured, and the temperature of the magnet 25 is detected more accurately. 【0080】Figures 9A and 10A show the positional relationship between the transmitting coil 51 and the receiving coil 61. Figure 9B shows the relationship between the misalignment and the coil coupling coefficient in the configuration shown in Figure 9A. Figure 10B shows the relationship between the misalignment and the coil coupling coefficient in the configuration shown in Figure 10A. 【0081】 The rotor 20 may experience misalignment in the rotation axis direction D. For example, in the configuration shown in Figure 7, the transmitting coil 51 and the receiving coil 61 face each other in the rotation axis direction D when the rotation angle of the rotor 20A is a predetermined angle. In this case, the distance α1 between the transmitting coil 51 and the receiving coil 61 in the rotation axis direction D, as shown in Figure 9A, changes according to the misalignment of the rotor 20 in the rotation axis direction D. In this case, as shown in Figure 9B, when the distance between coils is set to β in the design of the rotating electric machine MT, the distance between coils Δd １ There is a risk of misalignment occurring, and the distance between coils Δd １ The coupling coefficient fluctuates by approximately 0.08 depending on the misalignment. 【0082】 In contrast, in the configuration shown in Figure 2, the transmitting coil 51 and the receiving coil 61 face each other in a direction perpendicular to the rotation axis direction D when the rotation angle of the rotor 20 is a predetermined angle. In this case, the displacement distance α2 in the rotation axis direction D between the transmitting coil 51 and the receiving coil 61 shown in Figure 10A varies according to the displacement of the rotor 20 in the rotation axis direction D. In this case, as shown in Figure 10B, the displacement distance Δd ２ There is a risk of a misalignment, but the misalignment distance Δd ２ The coupling coefficient fluctuates by about 0.01 depending on the misalignment. Therefore, if the coil axis of the transmitting coil 51 extends in a direction perpendicular to the rotation axis, the influence of the rotor 20's positional misalignment on the temperature information output from the transmitting coil 51 is reduced. 【0083】The rotor 20 may further include a fixing member 70 for fixing the transmitting coil 51 to the shaft 21. The fixing member 70 may include a ring portion 71 and a support portion 72. The ring portion 71 may have a through hole 71a into which the shaft 21 is inserted and may be fixed to the shaft 21. The support portion 72 may be connected to the ring portion 71 and support the transmitting coil 51. In this case, the transmitting coil 51 can be fixed to the shaft 21 more easily and securely. 【0084】 By mounting the rotor 20 on the electric vehicle 200, the operating time of the cooling system for temperature control of the rotating electric machine MT can be appropriately controlled, and the operating time of the cooling system can be reduced. Therefore, the power consumption of the electric vehicle 200 can be reduced. 【0085】 While embodiments of the present invention have been described above, the present invention is not necessarily limited to the embodiments described above, and various modifications are possible without departing from the spirit of the invention. 【0086】 In the embodiments and modifications described above, the case where the magnet 25 is a permanent magnet was shown, but the magnet 25 may be an electromagnet. For example, a wound-field motor can be used instead of a motor using a permanent magnet. A wound-field motor has windings that generate a magnetic field when an electric current is passed through them, instead of a permanent magnet. The windings are field coils. A wound-field motor includes, for example, a plurality of field coils provided on a stator. 【0087】 Each magnet 25 may be formed by a combination of multiple magnets. When the magnets 25 are housed inside the gap S, the multiple magnets may be arranged in the direction of the rotation axis D. 【0088】As can be understood from the above-described embodiments and modifications, this specification includes the following embodiments: (Note 1) A rotor comprising: a magnet; a core that rotates while holding the magnet; a shaft provided on the rotation axis of the core; a temperature information transmitting device including a temperature sensing part for detecting temperature and a coil for outputting temperature information detected by the temperature sensing part, wherein the temperature sensing part is installed closer to the magnet than the coil, and the coil is installed on the shaft. (Note 2) The rotor according to Note 1, wherein the core has a gap extending in the direction of the rotation axis, the magnet is inserted into the gap, and the temperature sensing part is in contact with the surface of the magnet. (Note 3) The rotor according to Note 2, further comprising a positioning member for positioning the temperature sensing part so that it is in contact with the surface of the magnet, the temperature sensing part is in contact with the magnet inside the gap, and the positioning member presses the temperature sensing part toward the magnet. (Note 4) The rotor according to any one of Notes 1 to 3, wherein the coil shaft of the coil extends in a direction perpendicular to the direction of the rotation axis. (Note 5) The rotor according to any one of Notes 1 to 4, further comprising a fixing member for fixing the coil to the shaft, wherein the fixing member includes a ring portion having a through hole into which the shaft is inserted and fixed to the shaft, and a support portion connected to the ring portion and supporting the coil. (Note 6) A rotating electric machine comprising a stator, a rotor according to any one of Notes 1 to 5, and a temperature information receiving device provided on the stator and including a coil that is magnetically coupled to the coil of the rotor. (Note 7) An automobile comprising the rotating electric machine according to Note 6.(Note 8) A method for manufacturing a rotor, comprising attaching a temperature information transmitting device to a core that rotates around a shaft as a rotation axis while holding a magnet, the device including a temperature sensing unit for detecting temperature and a coil for outputting temperature information detected by the temperature sensing unit, wherein the temperature sensing unit is positioned closer to the magnet than the coil, and the coil is installed on the shaft. (Note 9) The method for manufacturing a rotor according to Note 8, wherein, in the installation of the temperature sensing unit, the temperature sensing unit is installed so as to be in contact with the surface of the magnet when the magnet is located inside a gap that extends in the direction of the rotation axis. (Note 10) The method for manufacturing a rotor according to Note 9, wherein, in the installation of the temperature sensing unit, the temperature sensing unit is positioned inside the gap so as to be pressed toward the magnet by a positioning member. (Note 11) The method for manufacturing a rotor according to any one of Notes 8 to 10, wherein, in the installation of the coil, the coil is installed on the shaft such that the coil axis of the coil extends in a direction perpendicular to the rotation axis. (Note 12) The method for manufacturing a rotor according to any one of Notes 8 to 11, wherein, in the installation of the coil, the shaft is inserted into the through hole of the ring portion of the fixing member that fixes the coil, thereby fixing the ring portion to the shaft, and the coil is supported by a support portion connected to the ring portion. (Note 13) The method for manufacturing a rotor according to any one of Notes 8 to 12, further comprising electrically connecting the temperature sensing element of the temperature sensing portion and the coil using circuit board wiring or wire wrapping. 【0089】 10...Stator, 20, 20A...Rotor, 21...Shaft, 25...Magnet, 50, 50A...Temperature information transmitting device, 52...Temperature sensing unit, 60, 60A...Temperature information receiving device, 70, 90...Fixing member, 71...Ring part, 71a...Through hole, 72, 92...Support part, 75...Positioning member, MT...Rotating electric machine, S...Gap.

Claims

Magnets and A core that rotates while holding the aforementioned magnet, A shaft provided on the rotation axis of the core, The device includes a temperature sensing unit that detects temperature and a coil that outputs information about the temperature detected by the temperature sensing unit, The temperature sensing element is installed in a position closer to the magnet than the coil. The coil is a rotor installed on the shaft. 　 The core has a gap that extends in the direction of the rotation axis, The magnet is inserted into the gap, The rotor according to claim 1, wherein the temperature sensing element is in contact with the surface of the magnet. 　 The system further includes a positioning member for positioning the temperature-sensing portion so that it contacts the surface of the magnet. The temperature-sensing part is in contact with the magnet inside the gap. The rotor according to claim 2, wherein the positioning member presses the temperature-sensing portion toward the magnet. 　 The rotor according to claim 1, wherein the coil axis of the coil extends in a direction perpendicular to the direction of the rotation axis. 　 The system further includes a fixing member for fixing the coil to the shaft, The rotor according to claim 1, wherein the fixing member includes a ring portion having a through hole into which the shaft is inserted and fixed to the shaft, and a support portion connected to the ring portion and supporting the coil. Stator and, A rotor according to any one of claims 1 to 5, A temperature information receiving device provided on the stator and including a coil that is magnetically coupled to the coil of the rotor, A rotating electric machine equipped with this feature. 　 An automobile equipped with the rotating electric machine described in claim 6. 　 A method for manufacturing a rotor, comprising attaching a temperature information transmitting device to a core that rotates around a shaft as its axis while holding a magnet, the device including a temperature sensing unit for detecting temperature and a coil for outputting temperature information detected by the temperature sensing unit, The temperature-sensing element is positioned closer to the magnet than the coil, A method for manufacturing a rotor, comprising installing the coil on the shaft. 　 The method for manufacturing a rotor according to claim 8, wherein, in the installation of the temperature sensing element, the temperature sensing element is installed so as to be in contact with the surface of the magnet when the magnet is located inside a gap that extends in the direction of the rotation axis. 　 The method for manufacturing a rotor according to claim 9, wherein, in the installation of the temperature sensing element, the temperature sensing element is positioned within the gap so as to be pressed toward the magnet by a positioning member. 　 The method for manufacturing a rotor according to claim 8, wherein, in the installation of the coil, the coil is installed on the shaft such that the coil axis of the coil extends in a direction perpendicular to the rotation axis. 　 In installing the aforementioned coil, The shaft is inserted into the through hole of the ring portion of the fixing member that secures the coil, thereby fixing the ring portion to the shaft. The method for manufacturing a rotor according to claim 8, wherein the coil is supported by a support portion connected to the ring portion. 　 A method for manufacturing a rotor according to any one of claims 8 to 12, further comprising electrically connecting the temperature sensing element of the temperature sensing unit and the coil using substrate wiring or wire wrapping.

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