Rotary electric machine

Abstract

To prevent a detection part from being charged by electrostatic induction and suppress deterioration of detection accuracy due to noise in a rotation angle calculation part.SOLUTION: A rotary electric machine includes: a rotating shaft rotatably supported; a rotor fixed to the rotating shaft and rotating integrally with the rotating shaft; an insulator coupled to a first end part of the rotating shaft; a conductive detection target part coupled to the insulator; a transmission part provided to face the detection target part in an axial direction of the rotating shaft and configured to transmit a magnetic field generating an induced current to the detection target part; a detection part including a reception part configured to receive the magnetic field generated by the induced current generated in the detection target part; and a rotation angle calculation part that calculates a rotation position of the rotor based on an output voltage of the reception part. The rotation shaft and the detected part are insulated from each other.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a rotating electric machine. [Background technology]

[0002] As disclosed in Patent Document 1, a position sensor is known in which a non-circular coupler made of a rotating conductive material is installed facing a circuit board. The circuit board in Patent Document 1 has a transmitting coil, a first receiving coil, and a second receiving coil. By installing such a position sensor coupler on the rotating shaft of a rotating electrical machine, it becomes possible to detect the rotation angle of the rotating shaft. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special publication 2013-518247 Summary of the Invention [Problem to be solved by the invention]

[0004] Generally, the rotating shaft is directly connected to the rotor inside the motor, and therefore becomes electrically charged when the motor rotates. In the configuration of Patent Document 1, the coupler (detected part) attached to the tip of the rotating shaft and the circuit board (detecting part) positioned opposite the detected part are located at a close distance of about several millimeters, and become electrically charged due to electrostatic induction. This electrical charge can cause noise in the rotation angle calculation part, which can lead to malfunctions and angle errors.

[0005] In view of the above-mentioned circumstances, the present disclosure aims to provide a rotating electric machine that can prevent the detection unit from becoming charged due to electrostatic induction and suppress deterioration of detection accuracy due to noise in the rotation angle calculation unit. [Means for solving the problem]

[0006] The rotating electric machine of the present disclosure comprises a rotatably supported rotating shaft, a rotor fixed to the rotating shaft and rotating integrally with the rotating shaft, an insulator coupled to a first end of the rotating shaft, a conductive detectable part coupled to the insulator, a detector arranged opposite the detectable part in the axial direction of the rotating shaft and having a transmitter that transmits a magnetic field that generates an induced current in the detectable part and a receiver that receives the magnetic field due to the induced current generated in the detectable part, and a rotation angle calculation part that calculates the rotational position of the rotor based on the output voltage of the receiver, wherein the rotating shaft and the detectable part are insulated from each other. [Effects of the Invention]

[0007] According to the present disclosure, it is possible to provide a rotating electric machine that can prevent the detection unit from being charged by electrostatic induction and suppress deterioration of detection accuracy due to noise in the rotation angle calculation unit. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a configuration diagram showing the overall configuration of a rotating electric machine according to a first embodiment of the present disclosure. [Figure 2] FIG. 2 is a plan view of a detection unit according to the first embodiment of the present disclosure. [Figure 3A] 2 is a diagram illustrating the shape of the detected part (metal plate) according to the first embodiment of the present disclosure, and is a top view of the rotating shaft, the insulator, and the detected part shown in FIG. 1. FIG. [Figure 3B] 3B is a side view showing the rotating shaft, the insulator, and the detected part of FIG. 3A. FIG. [Figure 3C] FIG. 10 is a diagram illustrating another shape of a detected part according to the first embodiment of the present disclosure, and is a top view showing a rotating shaft, an insulator, and a detected part. [Figure 3D] FIG. 3D is a side view showing the rotating shaft, the insulator, and the detected part of FIG. 3C. [Figure 3E] FIG. 10 is a diagram illustrating another shape of a detected part according to the first embodiment of the present disclosure, and is a top view showing a rotating shaft, an insulator, and a detected part. [Figure 3F] FIG. 3F is a side view showing the rotating shaft, the insulator, and the detected part of FIG. 3E. [Figure 4A] 5A and 5B are diagrams illustrating a method for connecting a rotating shaft and an insulator in the first embodiment. [Figure 4B] 10A to 10C are diagrams illustrating other methods of coupling the rotating shaft and the insulator in the first embodiment. [Figure 4C] 10A to 10C are diagrams illustrating other methods of coupling the rotating shaft and the insulator in the first embodiment. [Figure 4D] 10A to 10C are diagrams illustrating other methods of coupling the rotating shaft and the insulator in the first embodiment. [Figure 5A] 1A and 1B are diagrams illustrating an example of the shape of a detected part and a method of coupling a rotating shaft, an insulator, and a detected part in the first embodiment, and are top views of the rotating shaft, the insulator, and the detected part. [Figure 5B] 5B is a side view of the rotating shaft, the insulator, and the detected part shown in FIG. 5A. FIG. [Figure 5C] FIG. 5B is a perspective view of the rotating shaft, the insulator, and the detected part shown in FIG. 5A. [Figure 6] FIG. 10 is a configuration diagram showing the overall configuration of a rotating electric machine according to a second embodiment of the present disclosure. [Figure 7] FIG. 10 is a plan view of a detection unit according to a second embodiment of the present disclosure. [Figure 8A] FIG. 10 is a top view illustrating an example of the arrangement of a rotating shaft, an insulator, and a metal plating according to a second embodiment of the present disclosure. [Figure 8B] FIG. 8B is a side view showing the rotating shaft, insulator, and metal plating of FIG. 8A. [Figure 8C] 10A and 10B are top views illustrating other exemplary arrangements of a rotating shaft, an insulator, and a metal plating according to the second embodiment of the present disclosure. [Figure 8D] FIG. 8D is a side view showing the rotating shaft, insulator, and metal plating of FIG. 8C. [Figure 8E] 10A and 10B are top views illustrating other exemplary arrangements of the rotating shaft, the insulator, and the metal plating according to the second embodiment of the present disclosure. [Figure 8F] FIG. 8F is a side view showing the rotating shaft, insulator, and metal plating of FIG. 8E. [Figure 8G]10A and 10B are top views illustrating other exemplary arrangements of the rotating shaft, the insulator, and the metal plating according to the second embodiment of the present disclosure. [Figure 8H] FIG. 8F is a side view showing the rotating shaft, insulator, and metal plating of FIG. 8G. [Figure 9A] FIG. 11 is an example of a configuration diagram showing the overall configuration of a rotating electric machine according to a third embodiment of the present disclosure. [Figure 9B] FIG. 10 is a diagram illustrating another example of the rotating electric machine according to the third embodiment of the present disclosure. [Figure 10A] FIG. 10 is an example of a configuration diagram showing the overall configuration of a rotating electric machine according to a fourth embodiment of the present disclosure. [Figure 10B] FIG. 10 is a diagram illustrating another example of a rotating electric machine according to the fourth embodiment of the present disclosure. [Figure 11A] FIG. 11 is an example of a configuration diagram showing the overall configuration of a rotating electric machine according to a fifth embodiment of the present disclosure. [Figure 11B] FIG. 13 is a diagram illustrating another example of a rotating electric machine according to the fifth embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0009] <First Embodiment> The rotating electrical machine 1 according to the first embodiment will be described below with reference to the drawings. 1 is an overall view of a rotating electric machine 1. The rotating electric machine 1 includes a rotor 2, a rotating shaft 3, an insulator 4 coupled to a first end 3a of the rotating shaft 3, a detected part 5 coupled to the insulator 4, a detecting part 6 arranged to face the detected part 5, and a rotation angle calculating part 7. The detected part 5 is made of a conductive material and is provided in a region overlapping a part of the end face of the first end 3a of the rotating shaft 3. In this embodiment, the detected part 5 is a metal plate 50 made of a metal plate. The rotating shaft 3, insulator 4, and metal plate 50 are integrated and rotate around the axis O of the rotating shaft 3. In addition, in order to detect the rotation angle of the rotating shaft 3, the detection unit 6 is equipped with a rotation angle calculation unit 7. A rotor 2 connected to a rotating shaft 3 is provided inside the motor housing.

[0010] In this specification, the direction along the axis O of the rotating shaft 3 is referred to as the "axial direction." Furthermore, the direction that intersects with the axis O of the rotating shaft 3 when viewed from the axial direction is referred to as the "radial direction," and the direction that rotates around the axis O of the rotating shaft 3 is referred to as the "circumferential direction."

[0011] FIG. 2 is a diagram showing the configuration of the detection unit 6. As shown in FIG. The detection unit 6 has a transmitter that transmits a magnetic field that generates an induced current in the detection target 5, and a receiver that receives the magnetic field due to the induced current generated in the detection target 5. More specifically, the detection unit 6 is provided with a transmitter that has a transmitter coil 61 and a high-frequency AC source 62 that applies a high-frequency AC current to the transmitter coil 61, and a receiver that has a first receiver coil 63 and a second receiver coil 64. The rotation angle calculation unit 7 measures the voltage across the first receiver coil 63 and the voltage across the second receiver coil 64, and calculates the angle of the rotating shaft 3 (i.e., the rotational position of the rotor 2) based on the output voltages of these receivers. The rotation angle calculation unit 7 is provided on the detection unit 6. The transmission coil 61 has a plurality of circular loops arranged concentrically around the axis O (on the extension of the center line of the rotation axis 3).

[0012] The first receiving coil 63 has N loops when viewed in the axial direction, where N is an even number. Of the plurality of loops, two adjacent loops are wound in opposite directions. 2, N=2, and the first receiving coil 63 has a circular first loop 631 and a circular second loop 632 having a center at a different position from the first loop 631. The first loop 631 and the second loop 632 have the same diameter. The first receiving coil 63 is wound such that the winding directions of the loops are opposite at the connection point between the first loop 631 and the second loop 632. For example, if the first loop 631 is assumed to be wound counterclockwise, the second loop 632 is wound clockwise. In this way, the multiple loops of the first receiving coil 63 are connected in series while the winding directions of the loops are alternately reversed.

[0013] The second receiving coil 64 has the same shape as the first receiving coil 63, but is arranged so that its circumferential angle differs by 180 / N° from that of the first receiving coil 63. More specifically, the second receiving coil 64 has loops 641 and 642 that have the same shapes as the loops 631 and 632, respectively, and is arranged so that its circumferential angle differs by 90° from that of the first receiving coil 63.

[0014] The loops of the transmitting coil 61, the first receiving coil 63, and the second receiving coil 64 may be formed by printing a conductive material on the plate of the detection unit 6, or may be formed by forming a loop with a conductive wire and placing it on the plate.

[0015] 1, 3A, and 3B, in this embodiment, metal plate 50 is a semicircular plate centered on axis O, and has a diameter larger than rotation axis 3. When viewed from the axial direction, an imaginary circle including the circumferential portion of detection target portion 5 (metal plate 50) has a region (also referred to as first region R1) that overlaps with detection target portion 5 (metal plate 50) and a region (also referred to as second region R2) that does not overlap with detection target portion 5 (metal plate 50).

[0016] The metal plate 50 is disposed so as to face the detection unit 6 in the axial direction. The metal plate 50 is disposed at a position several mm away from the detection unit 6 in the axial direction (see FIG. 1). For ease of explanation, in FIG. 2, an example of the position of the metal plate 50 (i.e., the first region R1) is indicated by a dashed line, and an example of the position of the second region R2 is indicated by a two-dot chain line. The metal plate 50 rotates about the axis O in conjunction with the rotation shaft 3. Therefore, when viewed from the axial direction, the metal plate 50 rotates around the axis O while covering a portion of the first receiving coil 63 and a portion of the second receiving coil 64. In other words, as the metal plate 50 rotates, the positions of the first region R1 and the second region R2 move in the circumferential direction. In the example of FIG. 2, receiving coils 63 and 64 and metal plate 50 are arranged inside the loop of transmitting coil 61, and receiving coils 63 and 64 are provided inside an imaginary circle including the circumferential portion of metal plate 50.

[0017] <Method for detecting motor rotation angle> The voltage of each coil when the influence of the detected part 5 (metal plate 50) is ignored will be explained, and then the method for detecting the rotation angle will be explained. First, a description will be given of the case where the influence of the metal plate 50 is ignored. The transmitting coil 61 is excited by passing a high-frequency current through it. A voltage is generated in the first receiving coil 63 and the second receiving coil 64 due to electromagnetic induction. The first receiving coil 63 has N loops (N is an even number), with adjacent loops wound in opposite directions. That is, the loops are connected in series so that they are out of phase with each other. Therefore, although a voltage is generated locally due to electromagnetic induction, the voltage generated by electromagnetic induction is canceled out, and the voltage across both ends becomes zero. The second receiving coil 64 has the same shape as the first receiving coil 63, and is disposed at an angle that differs by 180 / N° in the circumferential direction from the first receiving coil 63. Therefore, in the second receiving coil 64, as in the first receiving coil 63, a voltage is generated locally due to electromagnetic induction, but the voltage across both ends is zero.

[0018] Next, we will explain the case where the influence of the metal plate 50 is taken into account. The metal plate 50 receives magnetic flux from the transmitting coil 61 and generates eddy currents. These eddy currents act in a direction that weakens the magnetic flux from the transmitting coil 61. Therefore, the voltage generated by electromagnetic induction in the first receiving coil 63 is smaller only in the portion covered by the metal plate 50 as viewed from the axial direction than in the portion not covered by the metal plate 50. That is, the voltage generated by electromagnetic induction in the portion of the first receiving coil 63 overlapping with the first region R1 is smaller than the voltage generated by electromagnetic induction in the portion overlapping with the second region R2. Due to this effect, electromagnetic induction is weakened only in a portion of the first receiving coil 63, causing a voltage imbalance. As a result, the voltage across both ends of the first receiving coil 63 is no longer zero and changes approximately sinusoidally as the metal plate 50 rotates. A similar phenomenon occurs in the second receiving coil 64, and the voltage at both ends of the second receiving coil 64 also changes in a sine wave shape. Here, the voltage that changes in a wave shape at both ends of the second receiving coil 64 has the same amplitude and period as the voltage at both ends of the first receiving coil 63, but the phase is shifted by 180 / N°. In the example shown in FIG. 2, the phases of the first receiving coil 63 and the second receiving coil 64 are shifted by 90°, resulting in a sine-cosine relationship. By obtaining the inverse tangent by the rotation angle calculation unit 7, the rotation angle of the metal plate 50 (that is, the rotation angle of the rotation shaft 3) can be calculated.

[0019] Here, since the metal plate 50 rotates in conjunction with the rotation shaft 3, it needs to be arranged at a distance from the detection unit 6. However, if the metal plate 50 and the detection unit 6 are separated too much, the effect of weakening the magnetic flux from the transmission coil 61 by eddy currents is reduced, so it is necessary to get as close as possible within a non-contact range. Since the metal plate 50 is charged with the electric charge transmitted from the rotation shaft 3, electrostatic induction occurs between the metal plate 50 and the detection unit 6 when the metal plate 50 is not insulated from the rotation shaft 3. Due to this electrostatic induction, noise or offset may occur in the voltage at both ends of the receiving coils 63 and 64, or it may have an adverse effect on the operation of the rotation angle calculation unit 7. Therefore, in the first embodiment, in order to insulate the rotation shaft 3 and the metal plate 50, an insulator 4 is provided between the rotation shaft 3 and the metal plate 50.

[0020] The effect of the first embodiment in which the insulator 4 is provided will be described. Let Ca be the stray capacitance between the metal plate 50 and the detection unit 6. Also, let Cb be the stray capacitance generated by sandwiching the insulator 4 between the rotation shaft 3 and the metal plate 50. Since the stray capacitances are arranged in series, if the combined value of the stray capacitances is C, the following formula (1) holds. 1 / C = 1 / Ca + 1 / Cb > 1 / Ca ···(1) From formula (1), C < Ca holds, and the stray capacitance can be reduced. Thereby, the influence of the electric charge carried by the rotation shaft 3 on the detection unit 6 can be reduced.

[0021] 3A to 3F and 5A to 5C show examples of rotating electric machines 1 using metal plates 50 of various shapes. In addition, in Fig. 3A to 3F and Fig. 5A to 5C, an insulator 4 is sandwiched between the rotating shaft 3 and the metal plate 50, and the rotating shaft 3 and the metal plate 50 are insulated from each other. 3A and 3B are diagrams illustrating details of the metal plate 50 described in Figures 1 and 2. The first end 3a of the rotating shaft 3 is provided with a semicircular first region R1 that overlaps with the metal plate 50, and a semicircular second region R2 that is a region other than the first region R1. 3C and 3D, the metal plate 50 has a pair of quarter-circular plates arranged to face each other across the axis O. This provides two first regions R1 and two second regions R2.

[0022] As shown in Figures 3E and 3F, the metal plate 50 may be composed of a semicircular first plate piece 50a having a first thickness (axial dimension) and a semicircular second plate piece 50b integrally formed with the first plate piece 50a and having a second thickness smaller than the first thickness. In this case, when viewed in the axial direction, a virtual circle including the circumferential portion of the metal plate 50 has a region overlapping the first plate piece 50a (first region R1) and a region overlapping the second plate piece 50b (second region R2). The first plate piece 50a is formed to protrude more axially toward the detection unit 6 than the second plate piece 50b. The axial distance between the first plate piece 50a and the detection unit 6 is smaller than the axial distance between the second plate piece 50b and the detection unit 6. The closer the detected portion 5 (metal plate 50) is to the detecting portion 6, the stronger the influence it has. Therefore, by providing the detected portion 5 (metal plate 50) having the above configuration, the voltage generated by electromagnetic induction in the portion of the first receiving coil 63 and the second receiving coil 64 that overlaps with the first region R1 (first plate piece 50a) is smaller than the voltage generated by electromagnetic induction in the portion that overlaps with the second region R2 (second plate piece 50b). As a result, the voltage across the first receiving coil 63 and the voltage across the second receiving coil 64 change in a roughly sinusoidal wave shape as the metal plate 50 rotates.

[0023] 5A to 5C, the metal plate 50 may be composed of a pair of quarter-circle-shaped first plate pieces 50a having a first thickness and a pair of quarter-circle-shaped second plate pieces 50b having a second thickness smaller than the first thickness. In this case, two first regions R1 and two second regions R2 are provided.

[0024] 3A to 3F and 5A to 5C, first regions R1 and second regions R2 are alternately provided in the circumferential direction by the metal plate 50. Furthermore, it is preferable that the total area of ​​the first regions R1 and the total area of ​​the second regions R2 are equal when viewed in the axial direction, and that the shapes of the first regions R1 and the second regions R2 are symmetrical with respect to the axis O. However, the total area of ​​the first regions R1 and the total area of ​​the second regions R2 may be different, and the regions R1 and R2 do not have to have shapes that are symmetrical with respect to the axis O. 3A to 3F and 5A to 5C are merely examples. When viewed from the axial direction, the metal plate 50 may have a polygonal shape, an elliptical shape, or a shape obtained by removing a part of any of these shapes.

[0025] 4A to 4D show an example of a method for connecting the rotating shaft 3 and the insulator 4. FIG. For example, as shown in Fig. 4A, the rotating shaft 3 and the insulator 4 may be respectively provided with a female thread 3f and a male thread 4m and then combined. As shown in Fig. 4B, the rotating shaft 3 and the insulator 4 may be respectively provided with a male thread 3m and a female thread 4f and then combined. As shown in FIG. 4C, the rotating shaft 3 and the insulator 4 may be assembled by drilling a screw hole or a hole and inserting an external screw 31 therein. 4D, the rotating shaft 3 and the insulator 4 may be combined by fitting them together by providing a convex portion 3p and a concave portion 4r on their surfaces. Alternatively, the rotating shaft 3 may have a concave portion and the insulator 4 may have a convex portion. Alternatively, although not shown, the rotating shaft 3 and the insulator 4 may be fixed together with an adhesive, or may be joined together by other methods.

[0026] 5A to 5C show an example of a method for joining the rotating shaft 3, the insulator 4, and the metal plate 50. The insulator 4 and the metal plate 50 may be assembled by drilling a tapped hole or a hole and inserting an external screw 31 into the hole. More specifically, the second plate piece 50b has a through-hole that penetrates in the axial direction. The metal plate 50 is fixed to the insulator 4 by the screw 31 that is inserted into the through-hole. The shape of the metal plate 50 and the method of joining the components may be a combination of the above-mentioned methods, or may be other methods. Furthermore, by making the metal plate 50 a non-magnetic material, the influence of magnetic flux from the rotating shaft 3 to the detection unit 6 can be reduced.

[0027] In this embodiment, the rotating electric machine 1 comprises a rotatably supported rotating shaft 3, a rotor 2 fixed to the rotating shaft 3 and rotating integrally with the rotating shaft 3, an insulator 4 connected to a first end 3a of the rotating shaft 3, a conductive detectable part 5 connected to the insulator 4, a detector 6 arranged opposite the detectable part 5 in the axial direction of the rotating shaft 3 and having a transmitter that transmits a magnetic field that generates an induced current in the detectable part 5 and a receiver that receives the magnetic field due to the induced current generated in the detectable part 5, and a rotation angle calculator 7 that calculates the rotational position of the rotor 2 based on the output voltage of the receiver, and the rotating shaft 3 and the detectable part 5 are insulated. The transmitting unit has a transmitting coil 61 through which a high-frequency alternating current flows, and the receiving unit has N loops 631, 632, where N is an even number, and a first receiving coil 63 having N loops 631, 632 wound in different directions with adjacent loops 631, 632, and a second receiving coil 64 having the same shape as the first receiving coil 63 and arranged at a circumferential angle different from the first receiving coil 63 by 180 / N°, and the rotation angle calculation unit 7 measures the output voltage at both ends of the first receiving coil 63 and the output voltage at both ends of the second receiving coil 64 and calculates the rotation angle of the rotating shaft 3.

[0028] The detected part 5 is a metal plate 50 connected to the insulator 4.

[0029] In this configuration, the insulator 4 provides insulation between the rotating shaft 3 and the detected part 5 (metal plate 50), thereby preventing the electric charge on the rotating shaft 3 from transferring to the metal plate 50, and preventing the detecting part 6 facing the metal plate 50 from being charged by electrostatic induction. Therefore, it is possible to prevent deterioration of detection accuracy due to noise in the rotation angle calculation part 7 caused by electrostatic induction.

[0030] <Embodiment 2> The rotating electrical machine 11 according to the second embodiment will be described below with reference to the drawings. The basic configuration of the second embodiment is the same as that of the first embodiment. Therefore, the same components are denoted by the same reference numerals and their description is omitted, and only the differences will be described. Note that the features of the first embodiment are also applicable to the second embodiment to the extent that they do not impair the features of the second embodiment.

[0031] 6 is an overall view of the rotating electric machine 11. In the first embodiment, the metal plate 50 serving as the detected part 5 is connected to the insulator 4, but in the second embodiment, the detected part 5 is a metal plating 51 applied to the insulator 4, which is different from the first embodiment.

[0032] An insulator 4 is coupled to a first end 3a of a rotating shaft 3 of a rotating electric machine 11. A metal plating 51 is applied to the end surface of the insulator 4 facing the detection unit 6, and the rotating shaft 3, insulator 4, and metal plating 51 rotate together. The metal plating 51 has a semicircular shape centered on the axis O, and the semicircular shape has a diameter equal to that of the insulator 4. The diameter of the insulator 4 is larger than the diameter of the rotating shaft 3. When viewed from the axial direction, in an imaginary circle including the circumferential portion of the metal plating 51, the region overlapping with the metal plating 51 is the first region R1, and the region not overlapping with the metal plating 51 is the second region R2.

[0033] Fig. 7 shows the configuration of the detection unit 6 in embodiment 2. In the example of Fig. 7, an example of the position of the metal plating 51 arranged away from the detection unit 6 in the axial direction is shown by a broken line.

[0034] 8A to 8H show examples of rotating electric machines 11 using various shapes of metal plating 51. In addition, in Fig. 8A to Fig. 8F, an insulator 4 is sandwiched between the rotating shaft 3 and the metal plating 51, and the rotating shaft 3 and the metal plating 51 are insulated from each other.

[0035] In the example shown in FIGS. 8A and 8B, a semicircular insulator 4 is provided at a first end 3a of a rotating shaft 3, with the axis O as its center. The diameter of the semicircle of the insulator 4 is larger than the diameter of the rotating shaft 3. A metal plating 51 is formed on the semicircular insulator 4. Therefore, in this example, a semicircular first region R1 overlapping with the metal plating 51 and a second region R2 that is a semicircular region other than the first region R1 are provided.

[0036] 8C and 8D, a cylindrical insulator 4 having a diameter larger than that of the rotating shaft 3 is provided at the end of the rotating shaft 3. Metal plating 51 is formed only on half of the end surface of the insulator 4 facing the detection unit 6. Thus, in this example, semicircular metal plating 51 having a diameter equal to that of the insulator 4 is provided. Also provided are a semicircular first region R1 overlapping with the metal plating 51, and a semicircular second region R2 other than the first region R1.

[0037] 8E and 8F, the metal plating 51 is formed on two of the four equal sections of the end surface of the insulator 4 facing the detection unit 6, and the two plated sections are arranged opposite each other across the axis O. Each plated section has a quarter-circle shape. As a result, plated first regions R1 and unplated second regions R2 are alternately arranged in the circumferential direction.

[0038] In the example shown in Figures 8G and 8H, the metal plating 51 is composed of a semicircular first plate piece 51a having a first thickness and a semicircular second plate piece 51b formed integrally with the first plate piece 51a and having a second thickness smaller than the first thickness.

[0039] When forming the metal plating 51 into a semicircular or quarter-circular shape, the insulator 4 may be processed into the desired shape before applying the metal plating 51, or the insulator 4 may remain circular, for example, and the metal plating 51 may be applied or formed only on a portion of the insulator 4 to form a semicircular or quarter-circular shape.

[0040] Furthermore, although not shown, it is also possible to provide irregularities on the end surface of the insulator 4, and process only the protrusion of the insulator 4 closest to the detection unit 6 into a semicircular or quarter-circular shape, and then apply or form metal plating 51 of equal thickness over the entire end surface of the insulator 4 having irregularities. Depending on the difference in the axial distance between the metal plating 51 and the detection unit 6, regions R1 and R2 can be provided.

[0041] The method for connecting the rotating shaft 3 and the insulator 4 is the same as that in the first embodiment described with reference to Figures 4A to 4D. Note that the method described with reference to Figures 4A to 4D is only an example, and other methods may be used, such as a method of fastening with screws, a method of connecting by fitting, a method of using an adhesive, or other methods.

[0042] According to the second embodiment, the detected part 5 of the rotating electrical machine 11 is a metal plating 51 applied to the insulator 4. The configuration of the second embodiment is such that the metal plate 50 of the first embodiment is replaced with a metal plating 51, and it is possible to obtain the same effects as those described in the first embodiment. Specifically, since the rotating shaft 3 and the metal plating 51 are insulated from each other, the charge on the rotating shaft 3 does not transfer to the metal plating 51, and the detection unit 6 facing the metal plating 51 is prevented from becoming charged due to electrostatic induction, thereby suppressing deterioration of detection accuracy due to noise in the rotation angle calculation unit 7.

[0043] <Third Embodiment> The rotating electrical machine 12 according to the third embodiment will be described below with reference to the drawings. The basic configuration of the third embodiment is the same as that of the first embodiment. Therefore, the same components are denoted by the same reference numerals and their description is omitted, and only the differences will be described. Note that the features of the first and second embodiments can also be applied to the second embodiment to the extent that they do not impair the features of the third embodiment.

[0044] 9A and 9B are overall views of a rotating electric machine 12 according to embodiment 3. Compared to embodiment 1 or 2, the insulator 4 is replaced with a non-magnetic insulator 41. The configuration other than the material of the non-magnetic insulator 41 is the same as that of embodiment 1 or 2.

[0045] 9A, the diameter of the rotating shaft 3 is equal to the diameter of the non-magnetic insulator 41. A semicircular metal plate 50 is provided on the non-magnetic insulator 41. The semicircle of the metal plate 50 has a larger diameter than the non-magnetic insulator 41. 9B, the diameter of the non-magnetic insulator 41 is larger than the diameter of the rotating shaft 3. On the non-magnetic insulator 41, a semicircular metal plating 51 is applied or formed. The method of connecting the non-magnetic insulator 41 to the rotating shaft 3, and the method of connecting the non-magnetic insulator 41 to the detected part 5 may be the same as the method of connecting each component described in embodiments 1 and 2, or may be another method.

[0046] According to the third embodiment, the insulator 4 of the rotating electrical machine 11 is a non-magnetic insulator 41, and the rotating shaft 3 and the part to be detected 5 are electrically and magnetically insulated from each other.

[0047] By using the non-magnetic insulator 41, the influence of the electric charge carried by the rotating shaft 3 on the detection unit 6 can be reduced, and the influence of the magnetic flux from the rotating shaft 3 to the detection unit 6 can also be reduced. In this way, the rotating shaft 3 and the part to be detected 5 are electrically and magnetically insulated, so that the influence of both the electric charge and the magnetic flux on the rotation angle calculation unit 7 can be suppressed.

[0048] <Fourth Embodiment> The rotating electrical machine 12 according to the fourth embodiment will be described below with reference to the drawings. The basic configuration of the fourth embodiment is the same as that of the first embodiment. Therefore, the same components are denoted by the same reference numerals and their description is omitted, and only the differences will be described. Note that the features of the first to third embodiments are also applicable to the fourth embodiment to the extent that they do not impair the features of the fourth embodiment.

[0049] 10A and 10B are overall views of a rotating electric machine 12 according to embodiment 4. In comparison with embodiments 1 to 3, embodiment 4 has a configuration in which non-magnetic insulators 41 and insulators 4 are stacked. The configuration other than this portion is the same as that of embodiments 1 to 3.

[0050] 10A and 10B, a non-magnetic insulator 41, an insulator 4, and a detected portion 5 (metal plate 50 or metal plating 51) are arranged in this order at the first end 3a of the rotating shaft 3. The insulator 4 may be made of a magnetic material. Of the non-magnetic insulator 41 and the insulator 4, the non-magnetic insulator 41 is disposed on the side farther from the detection unit 6. This can reduce the influence of leakage magnetic flux.

[0051] 10A, the rotating shaft 3, the non-magnetic insulator 41, and the insulator 4 have the same diameter. A semicircular metal plate 50 is provided on the insulator 4. The semicircle of the metal plate 50 has a larger diameter than the insulator 4. 10B, the diameters of the non-magnetic insulator 41 and the insulator 4 are larger than the diameter of the rotating shaft 3. On the insulator 4, a semicircular metal plating 51 is applied or formed. The method of connecting the rotating shaft 3, the non-magnetic insulator 41, and the insulator 4, and the method of connecting the insulator 4 and the detected part 5 may be the same as the method of connecting each component described in embodiments 1 to 3, or may be another method.

[0052] According to the fourth embodiment, the rotating electric machine 12 further includes a non-magnetic insulator 41 between the rotating shaft 3 and the insulator 4, so that the rotating shaft 3 and the part to be detected 5 are electrically and magnetically insulated from each other.

[0053] By stacking the non-magnetic insulator 41 and the insulator 4, the influence of the electric charge carried by the rotating shaft 3 on the detection unit 6 can be reduced, and the influence of the magnetic flux from the rotating shaft 3 to the detection unit 6 can also be reduced. In addition, a non-magnetic material is sandwiched between the rotating shaft 3 and the detected part 5, and furthermore, in the order in which the non-magnetic insulator 41 and the insulator 4 are arranged, the non-magnetic insulator 41 is arranged on the side farther from the detection part 6, thereby reducing the amount of magnetic flux leaking from the rotating shaft 3 that reaches the detection part 6. Furthermore, since the rotating shaft 3 and the part to be detected 5 are electrically and magnetically insulated, the influence of both the electric charge and the magnetic flux on the rotation angle calculation part can be suppressed.

[0054] <Fifth Embodiment> The rotating electric machine 13 according to the fifth embodiment will be described below with reference to the drawings. The basic configuration of the fifth embodiment is the same as that of the first embodiment. Therefore, the same components are denoted by the same reference numerals and their description is omitted, and only the differences will be described. Note that the features of the first to fourth embodiments are also applicable to the fifth embodiment to the extent that they do not impair the features of the fifth embodiment.

[0055] 11A and 11B are overall views of a rotating electric machine 13 according to embodiment 5. In embodiment 5, the configurations of embodiments 1 to 4 are applied to an electromechanical integrated motor in which a motor and an inverter are arranged adjacent to each other.

[0056] In a typical motor, a rotation signal obtained by a resolver or encoder is transmitted to a calculation board via electric wires and connectors. In contrast, in the fifth embodiment, the detection unit 6 is provided inside the inverter unit 8, taking advantage of the fact that the rotating shaft 3 and the detection unit 6 are not in contact with each other. 11A and 11B, the inverter unit 8 includes an inverter 82 that applies a voltage to the stator 2s that rotates the rotor 2, and a control unit 81 that controls the voltage applied to the inverter 82. Inside the inverter unit 8, a detection unit 6 and a rotation angle calculation unit 7 are provided. The control unit 81 and the detection unit 6 are on the same substrate. That is, the substrate is provided on a surface of the inverter unit 8 facing the rotation shaft 3, and includes the transmitting coil 61, the first receiving coil 63, the second receiving coil 64, the control unit 81, etc. In the example shown in FIGS. 11A and 11B, the control unit 81 and the detection unit 6 are provided on a substrate provided on a surface of the inverter 82 facing the rotation shaft 3. The rotation angle calculated by the rotation angle calculation unit 7 based on the output voltage of the detection unit 6 is configured to be used by the control unit 81. The inverter unit 8 may include a current detection unit that detects the current flowing through the stator 2s of the rotating electric machine 1. By arranging them on the same board, it is possible to omit electric wires and connectors, thereby reducing the number of parts and saving space.

[0057] Alternatively, the control unit 81 and the detection unit 6 may be disposed on separate boards provided on the same plane. That is, two boards are provided on the surface of the inverter unit 8 facing the rotation shaft 3, with the first of the two boards having the control unit 81 and the second having the detection unit 6. The first board and the second board are provided on the same plane. The plane is the surface of the inverter unit 8 facing the rotation shaft 3, and may be the surface of the inverter 82 facing the rotation shaft 3. By arranging the control unit 81 and the detection unit 6 on the same plane, it is possible to reduce the number of parts arranged in the axial direction, thereby making it possible to reduce the size. 11A and 11B, the rotation angle calculation unit 7 is shown separately from the control unit 81, but the control unit 81 may be provided with the function of the rotation angle calculation unit 7.

[0058] Thus, according to embodiment 5, the rotating electric machine 13 further includes a stator 2s, an inverter 82 that applies voltage to the stator 2s, and an inverter unit 8 having a control unit 81 that controls the voltage applied to the inverter 82. The detection unit 6 is provided on a surface of the inverter unit 8 facing the rotation axis 3. Furthermore, the control unit 81 and the detection unit 6 may be on the same plane, or the control unit 81 and the detection unit 6 may be on the same board. The inverter unit 8 is preferably disposed in a position facing the rotating shaft 3, with the detecting unit 6 provided on the surface facing the rotating shaft 3. Of the two surfaces through which the axis O of the inverter 82 passes, by disposing the detecting unit 6 on the surface facing the detected part 5, it is possible to shorten the distance between the detected part 5 and the detecting unit 6, thereby improving the S / N ratio of the output voltage of the detecting unit 6. On the other hand, it is possible to lengthen the distance between the detected part 5 and the inverter 82, which reduces the disturbance magnetic flux that interlinks with the detected part 5 caused by the current of the inverter 82, and it is possible to reduce distortion in the output voltage obtained by the detecting unit 6.

[0059] In addition, the rotating electric machine 13 may have the non-magnetic insulator 41, the insulator 4, and the detected part 5 stacked in this order on the first end 3a of the rotating shaft 3.

[0060] It is possible to combine the embodiments, or to modify or omit any of the embodiments as appropriate. For example, the detected part 5 may be made of a metal that is conductive and non-magnetic, thereby reducing the disturbance magnetic flux of the detecting part 6.

[0061] Various aspects of the present disclosure are summarized below as appendices.

[0062] (Appendix 1) a rotatably supported rotation shaft; a rotor fixed to the rotary shaft and rotating integrally with the rotary shaft; an insulator coupled to a first end of the rotating shaft; a conductive detection target portion coupled to the insulator; a detecting unit provided opposite the detected unit in the axial direction of the rotation shaft, the detecting unit including a transmitting unit that transmits a magnetic field that generates an induced current in the detected unit, and a receiving unit that receives the magnetic field caused by the induced current generated in the detected unit; a rotation angle calculation unit that calculates a rotation position of the rotor based on an output voltage of the receiving unit, The rotating electric machine has a rotating shaft and a detection target portion that are insulated from each other.

[0063] (Appendix 2) the transmitter has a transmission coil through which a high-frequency alternating current flows, the receiving unit includes a first receiving coil having N loops, where N is an even number, with adjacent loops wound in different directions, and a second receiving coil having the same shape as the first receiving coil and disposed at a circumferential angle different from that of the first receiving coil by 180 / N°; The rotation angle calculation unit measures an output voltage at both ends of the first receiving coil and an output voltage at both ends of the second receiving coil, and calculates a rotation angle of the rotation shaft. The rotating electric machine according to claim 1.

[0064] (Appendix 3) 3. The rotating electric machine according to claim 1, wherein the detected part is a metal plate coupled to the insulator.

[0065] (Appendix 4) 3. The rotating electric machine according to claim 1, wherein the detected part is a metal plating applied to the insulator.

[0066] (Appendix 5) 5. The rotating electric machine according to claim 1, wherein the part to be detected is made of a non-magnetic material.

[0067] (Appendix 6) the insulator is a non-magnetic insulator, 6. The rotating electric machine according to any one of claims 1 to 5, wherein the rotating shaft and the part to be detected are electrically and magnetically insulated from each other.

[0068] (Appendix 7) a non-magnetic insulator is further provided between the rotating shaft and the insulator; 7. The rotating electric machine according to any one of claims 1 to 6, wherein the rotating shaft and the part to be detected are electrically and magnetically insulated from each other.

[0069] (Appendix 8) A stator; an inverter unit having an inverter that applies a voltage to the stator and a control unit that controls the voltage applied to the inverter, 8. The rotating electric machine according to claim 1, wherein the detection unit is provided on a surface of the inverter unit facing the rotation axis.

[0070] (Appendix 9) A stator; an inverter unit having an inverter that applies a voltage to the stator and a control unit that controls the voltage applied to the inverter, 9. The rotating electric machine according to any one of claims 1 to 8, wherein the control unit and the detection unit are on the same plane.

[0071] (Appendix 10) A stator; an inverter unit having an inverter that applies a voltage to the stator and a control unit that controls the voltage applied to the inverter, 10. The rotating electric machine according to any one of appendices 1 to 9, wherein the control unit and the detection unit are on the same substrate. [Explanation of symbols]

[0072] 1, 11, 12, 13... rotating electric machine, 2... rotor, 2s... stator, 3... rotating shaft, 31... screw, 4... insulator, 41... non-magnetic insulator, 42... insulator or non-magnetic insulator, 5... detected part, 50... metal plate, 51... metal plating, 6... detection part, 61... transmitting coil, 62... high frequency AC source, 63... first receiving coil, 64... second receiving coil, 7... rotation angle calculation part, 8... inverter unit, 81... control part

Claims

1. a rotatably supported rotation shaft; a rotor fixed to the rotary shaft and rotating integrally with the rotary shaft; an insulator coupled to a first end of the rotating shaft; a conductive detection target portion coupled to the insulator; a detecting unit provided opposite the detected unit in the axial direction of the rotation shaft, the detecting unit including a transmitting unit that transmits a magnetic field that generates an induced current in the detected unit, and a receiving unit that receives the magnetic field caused by the induced current generated in the detected unit; a rotation angle calculation unit that calculates a rotation position of the rotor based on an output voltage of the receiving unit, The rotating electric machine has a rotating shaft and a detection target portion that are insulated from each other.

2. the transmitter has a transmission coil through which a high-frequency alternating current flows, The receiver unit includes a first receiver coil having N loops, where N is an even number, with adjacent loops wound in different directions, and a second receiver coil having the same shape as the first receiver coil and disposed at a circumferential angle different from that of the first receiver coil by 180 / N°; the rotation angle calculation unit measures an output voltage at both ends of the first receiving coil and an output voltage at both ends of the second receiving coil, and calculates a rotation angle of the rotation shaft; The rotating electric machine according to claim 1 .

3. The rotating electric machine according to claim 1 , wherein the detected part is a metal plate coupled to the insulator.

4. The rotating electric machine according to claim 1 , wherein the detected portion is a metal plating applied to the insulator.

5. The rotating electric machine according to claim 1 , wherein the detected part is made of a non-magnetic material.

6. the insulator is a non-magnetic insulator, The rotating electric machine according to claim 1 , wherein the rotating shaft and the detection target are electrically and magnetically insulated from each other.

7. a non-magnetic insulator is further provided between the rotating shaft and the insulator; The rotating electric machine according to claim 1 , wherein the rotating shaft and the detection target are electrically and magnetically insulated from each other.

8. A stator; an inverter unit having an inverter that applies a voltage to the stator and a control unit that controls the voltage applied to the inverter, The rotating electric machine according to claim 1 , wherein the detection section is provided on a surface of the inverter unit facing the rotation axis.

9. A stator; an inverter unit having an inverter that applies a voltage to the stator and a control unit that controls the voltage applied to the inverter, The rotating electric machine according to claim 1 , wherein the control unit and the detection unit are on the same plane.

10. A stator; an inverter unit having an inverter that applies a voltage to the stator and a control unit that controls the voltage applied to the inverter, The rotating electric machine according to claim 1 , wherein the control unit and the detection unit are mounted on the same substrate.

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