Torque ripple suppression device

Abstract

A mechanical angle of a rotating shaft of a motor can be detected more accurately and torque ripple can be suppressed more appropriately. A torque ripple suppression device (10) is provided with a magnetic field generation unit (12), a magnetic sensor (22), a mechanical angle detection unit (24), and a torque ripple compensation unit (26). The magnetic field generation unit (12) generates a magnetic field so as to satisfy the following (1) and (2). (1) One or more periods (B2)-(B5) among a plurality of periods (B1)-(B5) of a high level in the pulse signal each become a first predetermined period, and a period (B1) other than the one or more periods (B2)-(B5) is different from the first predetermined period. (2) one or more periods (C2) to (C4) among a plurality of periods (C1) to (C5) of a low level in the pulse signal are each a second predetermined period, and one or more periods (C1) and (C5) other than the one or more periods (C2) to (C4) are each different from the second predetermined period.

Description

Technical Field

[0001] The present invention relates to a torque ripple suppression device for suppressing torque ripple of a motor. Background Art

[0002] Conventionally, a device for suppressing torque ripple (Torque Ripple) of a motor has been known. For example, a torque ripple reduction device is disclosed in Patent Document 1, and the torque ripple reduction device includes a fluctuation generator that generates a torque equivalent to torque pulsation.

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: Japanese Patent Laid-Open No. 2001-197765 Summary of the Invention

[0006] However, in the torque ripple reduction device of Patent Document 1, the mechanical angle of the rotating shaft of the motor cannot be detected with good accuracy, and thus there is a problem that torque ripple cannot be appropriately suppressed.

[0007] The present invention has been made to solve such a problem, and an object thereof is to provide a torque ripple suppression device that can detect the mechanical angle of the rotating shaft of a motor with better accuracy and can more appropriately suppress torque ripple.

[0008] A torque ripple suppression device according to one aspect of the present invention includes: a magnetic field generation unit having one or more magnets that rotate together with a rotating shaft of a motor; a signal generation unit that generates a pulse signal based on a magnetic field that changes as the magnet rotates together with the rotating shaft; a mechanical angle detection unit that detects the mechanical angle of the rotating shaft based on the pulse signal generated by the signal generation unit; and a parameter determination unit that determines a parameter for suppressing the torque ripple of the motor based on the mechanical angle detected by the mechanical angle detection unit. The magnetic field generation unit generates the magnetic field so as to satisfy at least one of the following conditions (1) and (2).

[0009] Condition (1): Each of one or more first periods among a plurality of high-level periods in the pulse signal becomes a first specified period, and each of one or more second periods other than the one or more first periods is different from the first specified period.

[0010] Condition (2): Each of one or more third periods among a plurality of low-level periods in the pulse signal becomes a second specified period, and each of one or more fourth periods other than the one or more third periods is different from the second specified period.

[0011] The torque ripple suppression device according to the present invention can provide a torque ripple suppression device that can detect the mechanical angle of the rotating shaft of the motor with better accuracy and can more appropriately suppress torque ripple. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 FIG. is a view showing a motor having a torque ripple suppression device according to a first embodiment.

[0013] Figure 2 FIG. shows Figure 1 the magnetic field generation unit, the control substrate, and the magnetic core of the torque ripple suppression device.

[0014] Figure 3 FIG. shows Figure 1 the functional structure of the torque ripple suppression device.

[0015] Figure 4 FIG. shows an example of a pulse signal generated by Figure 1 the torque ripple suppression device.

[0016] Figure 5 FIG. is a view showing the magnetic field generation unit and the magnetic core of the torque ripple suppression device according to a second embodiment.

[0017] Figure 6 FIG. shows an example of a pulse signal generated by Figure 5 the torque ripple suppression device.

[0018] Figure 7 FIG. is a view showing the magnetic field generation unit and the magnetic core of the torque ripple suppression device according to a third embodiment.

[0019] Figure 8 FIG. shows an example of a pulse signal generated by Figure 7 the torque ripple suppression device.

[0020] Figure 9 FIG. is a view showing the magnetic field generation unit and the magnetic core of the torque ripple suppression device according to a fourth embodiment.

[0021] Figure 10 FIG. shows an example of a pulse signal generated by Figure 9 the torque ripple suppression device.

[0022] Figure 11 FIG. is a view showing the magnetic field generation unit and the magnetic core of the torque ripple suppression device according to a fifth embodiment.

[0023] Figure 12 FIG. shows an example of a pulse signal generated by Figure 11 the torque ripple suppression device.

[0024] Figure 13 FIG. 1 is a diagram showing a magnetic field generating section and a magnetic core of a torque ripple suppressing device according to a sixth embodiment.

[0025] Figure 14 FIG. 2 shows Figure 13 a perspective view of a magnetic field generating section of a torque ripple suppressing device.

[0026] Figure 15 FIG. 3 shows an example of a pulse signal generated by Figure 13 a torque ripple suppressing device.

[0027] Figure 16 FIG. 4 is a diagram showing a magnetic field generating section, a magnetic core, and a stator of a torque ripple suppressing device according to a seventh embodiment.

[0028] Figure 17 FIG. 5 is a diagram showing a magnetic field generating section and a magnetic core of a torque ripple suppressing device according to an eighth embodiment.

[0029] Figure 18 FIG. 6 is a diagram showing a magnetic field generating section of a torque ripple suppressing device according to a ninth embodiment. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] Hereinafter, embodiments of the present invention will be described. It should be noted that the embodiments described below are all specific examples of the present invention. Therefore, the numerical values, constituent elements, arrangement positions and connection methods of the constituent elements, steps, and the order of steps shown in the following embodiments are examples, and are not intended to limit the present invention. Therefore, the constituent elements not described in the independent claims among the constituent elements in the following embodiments are described as optional constituent elements.

[0031] In addition, each figure is a schematic diagram and is not necessarily strictly illustrated. It should be noted that in each figure, substantially the same structures are denoted by the same reference numerals, and redundant explanations are omitted or simplified.

[0032] (First Embodiment)

[0033] Figure 1 FIG. 7 is a diagram showing a motor 1 having a torque ripple suppressing device 10 according to the first embodiment. Figure 1 FIG. 8 shows the torque ripple suppressing device 10 and the like as viewed radially from the center of the rotation center line A of the rotation shaft 2 of the motor 1. In Figure 1 FIG. 8 and several other figures, the X-axis, Y-axis, and Z-axis are shown. The X-axis extends in the same direction as the rotation center line A, and the Y-axis and Z-axis are orthogonal to the X-axis and orthogonal to each other. That is, the XYZ orthogonal coordinate system is formed by the X-axis, Y-axis, and Z-axis. Hereinafter, the radial direction centered on the rotation center line A may be simply referred to as the radial direction.

[0034] The torque ripple suppression device 10 suppresses the torque ripple of the motor 1. Even when a low-cost position detection sensor such as a Hall sensor is used, the torque ripple suppression device 10 can detect the mechanical angle of the rotating shaft 2 of the motor 1 with better accuracy and can more appropriately suppress the torque ripple. As Figure 1 shown, the motor 1 has a rotating shaft 2, a rotor 3, and a stator 4. The rotating shaft 2 is mounted on the rotor 3. The rotor 3 rotates about the rotation center line A together with the rotating shaft 2 with respect to the stator 4. The torque ripple suppression device 10 includes a magnetic field generation unit 12 and a control board 14.

[0035] The magnetic field generation unit 12 is mounted on the front end portion of the rotating shaft 2. The magnetic field generation unit 12 is mounted on one end portion of the rotating shaft 2 in the extending direction (X-axis direction) of the rotation center line A. In the present embodiment, the magnetic field generation unit 12 is fixed to the rotating shaft 2 by the magnetic core 20 and thus mounted on the rotating shaft 2, the details of which will be described later. Hereinafter, the extending direction of the rotation center line A may be simply referred to as the rotation center line extending direction.

[0036] Figure 2 is a diagram showing Figure 1 the magnetic field generation unit 12, the control board 14, and the magnetic core 20 of the torque ripple suppression device 10. Figure 2 shows the magnetic field generation unit 12, the control board 14, and the magnetic core 20 as viewed from the rotation center line extending direction.

[0037] The magnetic field generation unit 12 generates a magnetic field. The magnetic field generation unit 12 generates a magnetic field in such a manner as to satisfy the following condition (1) and condition (2), the details of which will be described later.

[0038] Condition (1): Each of one or more first periods among the plurality of high-level periods in the pulse signal becomes a first specified period, and each of one or more second periods other than the one or more first periods is different from the first specified period.

[0039] Condition (2): Each of one or more third periods among the plurality of low-level periods in the pulse signal becomes a second specified period, and each of one or more fourth periods other than the one or more third periods is different from the second specified period.

[0040] The pulse signal shown by this condition (1) and this condition (2) is a pulse signal generated during one rotation of the rotating shaft 2 at a constant speed. As Figure 2 shown, the magnetic field generation unit 12 has one or more magnets 16a to 16j, a plurality of insulators 18a to 18t, and a magnetic core 20. The one or more magnets 16a to 16j are a plurality of magnets 16a to 16j.

[0041] A plurality of magnets 16a to 16j rotate together with the rotating shaft 2 of the motor 1. In the present embodiment, the plurality of magnets 16a to 16j are mounted on the rotating shaft 2 by means of a magnetic core 20 and rotate together with the rotating shaft 2. The plurality of magnets 16a to 16j are fixed to the magnetic core 20 in a state of being inserted into holes formed in the magnetic core 20.

[0042] The plurality of magnets 16a to 16j are arranged around the rotation center line A. The plurality of magnets 16c to 16j are arranged along the rotation direction of the rotating shaft 2. The plurality of magnets 16c to 16j are arranged at equal intervals along the rotation direction of the rotating shaft 2. Hereinafter, the rotation direction of the rotating shaft 2 may sometimes be simply referred to as the rotation direction.

[0043] As Figure 2 shown, each of the plurality of magnets 16a to 16j has a linear and elongated shape when viewed from the axial direction of the rotating shaft 2, and is arranged along the tangent of the circumference centered on the rotation center line A. In addition, the plurality of magnets 16a to 16j are arranged so as to surround the rotation center line A. In fact, in the present embodiment, each of the plurality of magnets 16a to 16j is in a flat plate shape, and is arranged such that the direction of the thickness of the flat plate constituting the magnet (hereinafter, simply referred to as the thickness direction) coincides with the radial direction. Hereinafter, the direction along the tangent of the circumference centered on the rotation center line A when viewed from the axial direction of the rotating shaft 2 may sometimes be simply referred to as the tangent direction.

[0044] The N poles and S poles of each of the plurality of magnets 16a to 16j are arranged in the radial direction. The magnetization direction of each of the plurality of magnets 16a to 16j is opposite to the magnetization directions of the magnets on both sides of the magnet among the plurality of magnets 16a to 16j. That is, the direction in which the N poles and S poles of each of the plurality of magnets 16a to 16j are arranged is opposite to the direction in which the N poles and S poles of the magnets on both sides of the magnet among the plurality of magnets 16a to 16j are arranged. For example, the direction in which the N pole and S pole of the magnet 16a are arranged is opposite to the direction in which the N pole and S pole of the magnet 16b adjacent to the magnet 16a are arranged, and is opposite to the direction in which the N pole and S pole of the magnet 16j adjacent to the magnet 16a are arranged.

[0045] The size in the tangent direction of each of one or more of the magnets 16c to 16j among the plurality of magnets 16a to 16j is a specified size, and the size in the tangent direction of one or more of the magnets 16a and 16b other than one or more of the magnets 16c to 16j is different from the specified size. That is, the sizes in the tangent direction of each of one or more of the magnets 16c to 16j are equal to each other. The size in the tangent direction of the magnet 16a is larger than the specified size, and the size in the tangent direction of the magnet 16b is smaller than the specified size. In the present embodiment, one or more of the magnets 16c to 16j are an example of one or more first magnets. In addition, one or more of the magnets 16a and 16b are an example of one or more second magnets.

[0046] The radial dimensions of the multiple magnets 16a to 16j are equal to each other. In addition, the dimensions of the multiple magnets 16a to 16j in the extending direction of the rotation center line are equal to each other.

[0047] The multiple insulators 18a to 18t are each formed of an insulating material.

[0048] The magnetic core 20 is formed by laminating a plurality of electromagnetic steel sheets. For example, the electromagnetic steel sheet is a silicon steel sheet. The magnetic core 20 is fixed to the rotating shaft 2. The multiple magnets 16a to 16j are embedded in the magnetic core 20.

[0049] The control substrate 14 has a magnetic sensor 22. The magnetic sensor 22 is an example of a generation unit that generates a pulse signal based on a magnetic field that changes as the multiple magnets 16a to 16j rotate together with the rotating shaft 2. The magnetic sensor 22 is disposed at a position where it can detect the magnetic field generated by the multiple magnets 16a to 16j. In the present embodiment, the magnetic sensor 22 is disposed outside the multiple magnets 16a to 16j in the radial direction. For example, the magnetic sensor 22 is a Hall sensor.

[0050] Figure 3 is a block diagram showing Figure 1 the functional structure of the torque ripple suppression device 10. Figure 4 is a diagram showing an example of Figure 1 the pulse signal generated by the torque ripple suppression device 10. Figure 4 is a diagram showing an example of the pulse signal generated during the period when the rotating shaft 2 rotates at a constant speed.

[0051] As Figure 3 shown, the control substrate 14 also has a mechanical angle detection unit 24, a torque ripple compensation unit 26, and a cogging effect compensation unit 28. For example, the mechanical angle detection unit 24, the torque ripple compensation unit 26, and the cogging effect compensation unit 28 are implemented by a processor or the like.

[0052] The magnetic sensor 22 converts the magnitude and orientation of the magnetic field that changes as the multiple magnets 16a to 16j rotate together with the rotating shaft 2 into Figure 4 a current value as shown. For example, the magnetic sensor 22 also generates a pulse signal that becomes high level if the converted current value is equal to or greater than a specified value, and becomes low level if the converted current value is less than the specified value.

[0053] One or more of the periods B2 to B5 of the high level in the pulse signal each become a first specified period, and one or more of the periods B1 other than the one or more periods B2 to B5 are different from the first specified period. That is, the one or more periods B2 to B5 are equal to each other. The period B1 is longer than the first specified period. In the present embodiment, the one or more periods B2 to B5 are an example of one or more first periods. In addition, the one or more periods B1 are an example of one or more second periods.

[0054] In addition, one or more of the periods C2 to C4 of the low level in the pulse signal each become a second specified period, and one or more of the periods C1 and C5 other than the one or more periods C2 to C4 are each different from the second specified period. That is, the one or more periods C2 to C4 are equal to each other. The period C1 is shorter than the second specified period. The period C5 is longer than the second specified period. In the present embodiment, the one or more periods C2 to C4 are an example of one or more third periods. In addition, the one or more periods C1 and C5 are an example of one or more fourth periods.

[0055] In this way, since the dimension in the tangential direction of the magnet 16a is larger than the specified dimension, the period B1 is longer than the first specified period, and the period C5 is longer than the second specified period. In addition, since the dimension in the tangential direction of the magnet 16b is smaller than the specified dimension, the period C1 is shorter than the second specified period.

[0056] The mechanical angle detection unit 24 detects the mechanical angle of the rotating shaft 2 based on the pulse signal generated by the magnetic sensor 22. Since a pulse having a period B1 different from the first specified period is generated once during one rotation of the rotating shaft 2, for example, the mechanical angle detection unit 24 can detect the mechanical angle of the rotating shaft 2 by using the mechanical angle at the timing of generation of the pulse of the period B1 as 0°.

[0057] Return Figure 3 , the torque ripple compensation unit 26 is an example of a determination unit that determines parameters for suppressing torque ripple based on the mechanical angle detected by the mechanical angle detection unit 24. For example, if the motor 1 generates n times of torque ripple = Asin(nθm + θ'), the torque ripple compensation unit 26 determines the parameters A and θ' in order to generate a torque = -Asin(nθm + θ') that suppresses the torque ripple. A is the amplitude of the torque ripple, θm is the mechanical angle, and θ' is the phase of the torque ripple. Regarding the method of determining the parameters A and θ' based on the mechanical angle, various known techniques can be used.

[0058] The cogging effect compensation unit 28 determines parameters for suppressing the cogging effect based on the mechanical angle detected by the mechanical angle detection unit 24. Regarding the method of determining the parameters based on the mechanical angle, various known techniques can be used.

[0059] The current control unit 6 outputs a current to the inverter 7 based on the current command corrected by the adder 30 and the adder 32.

[0060] The inverter 7 converts the current output by the current control unit 6 into alternating current and outputs it to the motor 1.

[0061] The motor 1 rotates based on the current output by the inverter 7. By rotating the motor 1 (rotating shaft 2), the magnetic field generation unit 12 rotates.

[0062] The torque ripple suppression device 10 of the first embodiment includes a magnetic field generation unit 12, a signal generation unit (magnetic sensor 22), a mechanical angle detection unit 24, and a parameter determination unit (torque ripple compensation unit 26). The magnetic field generation unit 12 has one or more magnets 16a to 16j that rotate together with the rotating shaft 2 of the motor 1. The signal generation unit (magnetic sensor 22) generates a pulse signal based on the magnetic field that changes as the one or more magnets 16a to 16j rotate together with the rotating shaft 2. The mechanical angle detection unit 24 detects the mechanical angle of the rotating shaft 2 based on the pulse signal generated by the signal generation unit (magnetic sensor 22). The parameter determination unit (torque ripple compensation unit 26) determines a parameter for suppressing the torque ripple of the motor 1 based on the mechanical angle detected by the mechanical angle detection unit 24. The magnetic field generation unit 12 generates a magnetic field in a manner that satisfies the following condition (1) and condition (2).

[0063] Condition (1): One or more of the periods B2 to B5 among the multiple high-level periods B1 to B5 in the pulse signal each become a first specified period, and one or more of the periods B1 other than the one or more periods B2 to B5 are different from the first specified period.

[0064] Condition (2): One or more of the periods C2 to C4 among the multiple low-level periods C1 to C5 in the pulse signal each become a second specified period, and one or more of the periods C1 and C5 other than the one or more periods C2 to C4 are each different from the second specified period.

[0065] Accordingly, since one or more of the periods B1 other than the one or more periods B2 to B5 among the multiple high-level periods B1 to B5 in the pulse signal are different from the first specified period, the mechanical angle of the rotating shaft 2 can be detected more accurately, and the torque ripple can be suppressed more appropriately. In addition, since one or more of the periods C1 and C5 other than the one or more periods C2 to C4 among the multiple low-level periods C1 to C5 in the pulse signal are each different from the second specified period, the mechanical angle of the rotating shaft 2 can be detected more accurately, and the torque ripple can be suppressed more appropriately.

[0066] In addition, in the torque ripple suppression device 10 of the first embodiment, one or more magnets 16a to 16j are a plurality of magnets 16a to 16j. The plurality of magnets 16a to 16j are arranged around the rotation center line A of the rotation shaft 2, each arranged along the tangential direction of the rotation direction of the rotation shaft 2, and their N poles and S poles are arranged radially around the rotation center line A, and their magnetization directions are opposite to the magnetization directions of the magnets on both sides of the magnet among the plurality of magnets 16a to 16j. The dimensions in the tangential direction of one or more of the magnets 16c to 16j among the plurality of magnets 16a to 16j are a specified dimension, and the dimensions in the tangential direction of one or more of the magnets 16a and 16b other than the one or more magnets 16c to 16j are different from the specified dimension.

[0067] Accordingly, since the dimensions in the tangential direction of one or more of the magnets 16a and 16b other than the one or more magnets 16c to 16j among the plurality of magnets 16a to 16j are different from the specified dimension, one or more periods B1 can be made different from the first specified period, and one or more of the periods C1 and C5 can be made different from the second specified period. Therefore, the mechanical angle of the rotation shaft 2 can be detected easily and with better accuracy, and torque ripple can be suppressed easily and more appropriately.

[0068] In addition, in the torque ripple suppression device 10 of the first embodiment, the magnetic field generating unit 12 is mounted on the front end portion of the rotation shaft 2.

[0069] Accordingly, it is easy to mount the magnetic field generating unit 12 on the rotation shaft 2.

[0070] (Second Embodiment)

[0071] Figure 5 FIG. is a diagram showing the magnetic field generating unit 42 and the magnetic core 50 of the torque ripple suppression device of the second embodiment. Figure 5 FIG. shows the magnetic field generating unit 42 and the magnetic core 50 as viewed from the extending direction of the rotation center line.

[0072] The torque ripple suppression device of the second embodiment is mainly different from the torque ripple suppression device 10 in that it includes a magnetic field generating unit 42 instead of the magnetic field generating unit 12. Hereinafter, the differences from the magnetic field generating unit 12 will be mainly described.

[0073] The magnetic field generating unit 42 generates a magnetic field. The magnetic field generating unit 42 generates a magnetic field in such a manner as to satisfy the following condition (1), and the details will be described later.

[0074] Condition (1): Each of one or more first periods among the periods of high level in the pulse signal becomes a first specified period, and each of one or more second periods other than the one or more first periods is different from the first specified period.

[0075] The pulse signal shown in the condition (1) is a pulse signal generated during one rotation of the rotating shaft 2 at a constant speed. As Figure 5 shown, the magnetic field generating unit 42 includes one or more magnets 46a to 46j, a plurality of insulators 48a to 48t, and a magnetic core 50. The one or more magnets 46a to 46j are a plurality of magnets 46a to 46j.

[0076] The plurality of magnets 46a to 46j are arranged along the rotation direction. The plurality of magnets 46a to 46j are arranged at equal intervals along the rotation direction of the rotating shaft 2.

[0077] The plurality of magnets 46a to 46j are each arranged along the tangential direction. That is, the plurality of magnets 46a to 46j are each linear along the tangential direction. In the present embodiment, the plurality of magnets 46a to 46j are each plate-shaped and are arranged such that the thickness direction of the magnet coincides with the radial direction.

[0078] The N poles and S poles of the plurality of magnets 46a to 46j are arranged along the radial direction. The magnetization directions of the plurality of magnets 46a to 46j are opposite to the magnetization directions of the magnets on both sides of the magnet among the plurality of magnets 46a to 46j. That is, the directions in which the N poles and S poles of the plurality of magnets 46a to 46j are arranged are opposite to the directions in which the N poles and S poles of the magnets on both sides of the magnet among the plurality of magnets 46a to 46j are arranged. For example, the directions in which the N pole and S pole of the magnet 46a are arranged are opposite to the directions in which the N pole and S pole of the magnet 46b adjacent to the magnet 46a are arranged, and are opposite to the directions in which the N pole and S pole of the magnet 46j adjacent to the magnet 46a are arranged.

[0079] The magnitudes of the magnetic fluxes of one or more of the plurality of magnets 46b to 46j are a specified magnitude, and the magnitudes of the magnetic fluxes of one or more of the magnets 46a other than the one or more magnets 46b to 46j are different from the specified magnitude. That is, the magnitudes of the magnetic fluxes of the one or more magnets 46b to 46j are equal to each other. The magnitude of the magnetic flux of the magnet 46a is larger than the specified magnitude. It should be noted that the magnitude of the magnetic flux of the magnet 46a may also be smaller than the specified magnitude. In the present embodiment, the one or more magnets 46b to 46j are an example of one or more first magnets. In addition, the one or more magnets 46a are an example of one or more second magnets.

[0080] The dimensions of the plurality of magnets 46a to 46j in the tangential direction are equal to each other. In addition, the dimensions of the plurality of magnets 46a to 46j in the radial direction are equal to each other. In addition, the dimensions of the plurality of magnets 46a to 46j in the direction in which the rotation center line extends are equal to each other.

[0081] Figure 6 is shown by Figure 5A diagram showing an example of a pulse signal generated by a torque ripple suppression device. Figure 6 Shows an example of a pulse signal generated during the period when the rotating shaft 2 rotates at a constant speed.

[0082] As Figure 6 Shown, one or more of the periods D2 - D5 with a high level in the pulse signal each become a first specified period, and one or more of the periods D1 other than one or more of the periods D2 - D5 are different from the first specified period. That is, one or more of the periods D2 - D5 are equal to each other. The period D1 is longer than the first specified period. In the present embodiment, one or more of the periods D2 - D5 are an example of one or more first periods. In addition, one or more of the periods D1 are an example of one or more second periods.

[0083] In this way, since the magnitude of the magnetic flux of the magnet 46a is larger than a specified magnitude, the period D1 is longer than the first specified period.

[0084] In the torque ripple suppression device of the second embodiment, one or more of the magnets 46a - 46j are a plurality of magnets 46a - 46j. The plurality of magnets 46a - 46j are arranged along the rotation direction of the rotating shaft 2, each arranged along the tangential direction of the rotation direction, and their N - poles and S - poles are arranged radially around the rotation center line A of the rotating shaft 2, and their magnetization directions are opposite to the magnetization directions of the magnets on both sides of the magnet among the plurality of magnets 46a - 46j. The magnitude of the magnetic flux of one or more of the magnets 46b - 46j among the plurality of magnets 46a - 46j is a specified magnitude, and the magnitude of the magnetic flux of one or more of the magnets 46a other than one or more of the magnets 46b - 46j is different from the specified magnitude.

[0085] Accordingly, since the magnitude of the magnetic flux of one or more of the magnets 46a other than one or more of the magnets 46b - 46j among the plurality of magnets 46a - 46j is different from the specified magnitude, one or more of the periods D1 can be made different from the first specified period. Thus, the mechanical angle of the rotating shaft 2 can be detected more easily and with better accuracy, and torque ripple can be suppressed more easily and appropriately.

[0086] (Third Embodiment)

[0087] Figure 7 Is a diagram showing the magnetic field generating portion 62 and the magnetic core 70 of the torque ripple suppression device of the third embodiment. Figure 7 Shows the magnetic field generating portion 62 and the magnetic core 70 as observed from the direction of the extension of the rotation center line.

[0088] The torque ripple suppression device of the third embodiment is different from the torque ripple suppression device 10 mainly in that it includes a magnetic field generation unit 62 instead of the magnetic field generation unit 12. Hereinafter, the differences from the magnetic field generation unit 12 will be mainly described.

[0089] The magnetic field generation unit 62 generates a magnetic field. The magnetic field generation unit 62 generates a magnetic field in such a manner as to satisfy the following condition (1), and the details will be described later.

[0090] Condition (1): Each of one or more first periods among the high-level periods in the pulse signal becomes a first specified period, and each of one or more second periods other than the one or more first periods is different from the first specified period.

[0091] The pulse signal shown in this condition (1) is a pulse signal generated during one revolution of the rotating shaft 2 at a constant speed. As Figure 7 shown, the magnetic field generation unit 62 includes one or more magnets 66a to 66j, a plurality of insulators 68a to 68t, and a magnetic core 70. The one or more magnets 66a to 66j are a plurality of magnets 66a to 66j.

[0092] The plurality of magnets 66a to 66j are arranged in the rotational direction. The plurality of magnets 66a to 66j are arranged at equal intervals in the rotational direction of the rotating shaft 2.

[0093] The plurality of magnets 66a to 66j are each arranged along the tangential direction. That is, the plurality of magnets 66a to 66j are each linear along the tangential direction. In the present embodiment, the plurality of magnets 66a to 66j are each plate-shaped and arranged such that the thickness direction of the magnet coincides with the radial direction.

[0094] The N poles and S poles of the plurality of magnets 66a to 66j are arranged in the radial direction. The magnetization direction of each of the plurality of magnets 66a to 66j is opposite to the magnetization directions of the magnets on both sides of the magnet among the plurality of magnets 66a to 66j. That is, the direction in which the N poles and S poles of the plurality of magnets 66a to 66j are arranged is opposite to the direction in which the N poles and S poles of the magnets on both sides of the magnet among the plurality of magnets 66a to 66j are arranged. For example, the direction in which the N pole and S pole of the magnet 66a are arranged is opposite to the direction in which the N pole and S pole of the magnet 66b adjacent to the magnet 66a are arranged, and is opposite to the direction in which the N pole and S pole of the magnet 66j adjacent to the magnet 66a are arranged.

[0095] One or more of the magnets 66b to 66j among the plurality of magnets 66a to 66j do not have holes, and one or more of the magnets 66a other than the one or more magnets 66b to 66j have holes 72 penetrating in a direction parallel to the X-axis. In the present embodiment, one or more of the magnets 66b to 66j are an example of one or more first magnets. In addition, one or more of the magnets 66a are an example of one or more second magnets.

[0096] The dimensions in the tangential direction of the plurality of magnets 66a to 66j are equal to each other. In addition, the dimensions in the radial direction of the plurality of magnets 66a to 66j are equal to each other. In addition, the dimensions in the direction of extension of the rotation center of the plurality of magnets 66a to 66j are equal to each other.

[0097] Figure 8 It is a diagram showing an example of a pulse signal generated by Figure 7 the torque ripple suppression device. Figure 8 It shows an example of a pulse signal generated during the constant-speed rotation of the rotating shaft 2.

[0098] As Figure 8 shown, one or more of the periods E2 to E5 of the high level in the pulse signal each become a first specified period, and one or more of the periods E1 other than the one or more periods E2 to E5 are different from the first specified period. That is, one or more of the periods E2 to E5 are equal to each other. The period E1 is shorter than the first specified period. In the present embodiment, one or more of the periods E2 to E5 are an example of one or more first periods. In addition, one or more of the periods E1 are an example of one or more second periods.

[0099] Thus, by providing the holes 72 in the magnetic poles located on the outer side in the radial direction of the N pole and the S pole of the magnet 66a, the magnitude of the magnetic flux of the magnet 66a is smaller than the magnitude of the magnetic flux of each of the one or more magnets 66b to 66j, and the period E1 is shorter than the first specified period.

[0100] In the torque ripple suppression device of the third embodiment, one or more of the magnets 66a to 66j are the plurality of magnets 66a to 66j. The plurality of magnets 66a to 66j are arranged along the rotation direction of the rotating shaft 2, are each arranged along the tangential direction of the rotation direction, the N poles and the S poles of each are arranged in the radial direction centered on the rotation center line of the rotating shaft 2, and the magnetization direction of each is opposite to the magnetization direction of the magnets on both sides of the magnet among the plurality of magnets 66a to 66j. In the N poles and the S poles of one or more of the magnets 66b to 66j among the plurality of magnets 66a to 66j, the magnetic poles located on the outer side in the radial direction do not have holes, and the N poles and the S poles of one or more of the magnets 66a other than the one or more magnets 66b to 66j have holes in the magnetic poles located on the outer side in the radial direction.

[0101] Accordingly, one or more of the magnets 66a among the plurality of magnets 66a to 66j are provided with holes except for one or more of the magnets 66b to 66j. Therefore, the magnitude of the magnetic flux of the magnet 66a can be made smaller than the magnitude of the magnetic flux of each of the one or more magnets 66b to 66j, and one or more periods E1 can be made different from the first specified period. Thus, the mechanical angle of the rotating shaft 2 can be detected easily and with better accuracy, and torque fluctuations can be suppressed easily and more appropriately.

[0102] (Fourth Embodiment)

[0103] Figure 9 FIG. is a diagram showing the magnetic field generating unit 82 and the magnetic core 90 of the torque fluctuation suppressing device according to the fourth embodiment. Figure 9 FIG. (a) shows the magnetic field generating unit 82 and the magnetic core 90 as viewed from the direction extending from the rotation center line. Figure 9 FIG. (b) shows the magnets 86a, 86b, 86i as viewed from the radial direction.

[0104] The torque fluctuation suppressing device according to the fourth embodiment mainly differs from the torque fluctuation suppressing device 10 in that it includes a magnetic field generating unit 82 instead of the magnetic field generating unit 12. Hereinafter, the description will focus on the differences from the magnetic field generating unit 12.

[0105] The magnetic field generating unit 82 generates a magnetic field. The magnetic field generating unit 82 generates a magnetic field in such a manner as to satisfy the following condition (1), the details of which will be described later.

[0106] Condition (1): Each of one or more first periods among the plurality of high-level periods in the pulse signal becomes a first specified period, and each of one or more second periods other than the one or more first periods is different from the first specified period.

[0107] The pulse signal shown in this condition (1) is a pulse signal generated during one rotation of the rotating shaft 2 at a constant speed. As Figure 9 shown, the magnetic field generating unit 82 includes one or more magnets 86a to 86j, a plurality of insulators 88a to 88t, and a magnetic core 90. The one or more magnets 86a to 86j are the plurality of magnets 86a to 86j.

[0108] The plurality of magnets 86a to 86j are arranged in the rotation direction. The plurality of magnets 86a to 86j are arranged at equal intervals in the rotation direction of the rotating shaft 2.

[0109] The plurality of magnets 86a to 86j are each arranged along the tangential direction. That is, the plurality of magnets 86a to 86j are each linear along the tangential direction. In the present embodiment, the plurality of magnets 86a to 86j are each plate-shaped and arranged such that the thickness direction of the magnet coincides with the radial direction.

[0110] The N - poles and S - poles of each of the plurality of magnets 86a to 86j are arranged radially. The magnetization direction of each of the plurality of magnets 86a to 86j is opposite to the magnetization directions of the magnets on both sides of that magnet among the plurality of magnets 86a to 86j. That is, the direction in which the N - poles and S - poles of each of the plurality of magnets 86a to 86j are arranged is opposite to the direction in which the N - poles and S - poles of the magnets on both sides of that magnet among the plurality of magnets 86a to 86j are arranged. For example, the direction in which the N - pole and S - pole of magnet 86a are arranged is opposite to the direction in which the N - pole and S - pole of the adjacent magnet 86b to magnet 86a are arranged, and is also opposite to the direction in which the N - pole and S - pole of the adjacent magnet 86j to magnet 86a are arranged.

[0111] The dimensions in the extending direction of the rotation center line of one or more of the plurality of magnets 86b to 86j among the plurality of magnets 86a to 86j are a specified dimension, and the dimensions in the extending direction of the rotation center line of one or more of the magnets 86a other than one or more of the magnets 86b to 86j are different from the specified dimension. That is, the dimensions in the extending direction of each of one or more of the magnets 86b to 86j are equal to each other. The dimension in the extending direction of magnet 86a is smaller than the specified dimension. It should be noted that the dimension in the extending direction of magnet 86a may also be larger than the specified dimension. In the present embodiment, one or more of the magnets 86b to 86j are an example of one or more first magnets. In addition, one or more of the magnets 86a are an example of one or more second magnets.

[0112] The dimensions in the tangential direction of the plurality of magnets 86a to 86j are equal to each other. In addition, the dimensions in the radial direction of the plurality of magnets 86a to 86j are equal to each other.

[0113] Figure 10 It is a diagram showing an example of a pulse signal generated by Figure 9 the torque fluctuation suppression device. Figure 10 It shows an example of a pulse signal generated during the period when the rotating shaft 2 rotates at a constant speed.

[0114] As Figure 10 shown, one or more of the periods F2 to F5 among the plurality of high - level periods F1 to F5 in the pulse signal each become a first specified period, and one or more of the periods F1 other than one or more of the periods F2 to F5 are different from the first specified period. That is, one or more of the periods F2 to F5 are equal to each other. Period F1 is shorter than the first specified period. In the present embodiment, one or more of the periods F2 to F5 are an example of one or more first periods. In addition, one or more of the periods F1 are an example of one or more second periods.

[0115] In this way, the dimension in the extending direction of the rotation center line of the magnet 86a is smaller than the specified dimension, so that the magnitude of the magnetic flux of the magnet 86a is smaller than the magnitude of the magnetic flux of each of the one or more magnets 86b to 86j, and the period F1 is shorter than the first specified period.

[0116] In the torque ripple suppression device according to the fourth embodiment, the one or more magnets 86a to 86j are a plurality of magnets 86a to 86j. The plurality of magnets 86a to 86j are arranged along the rotation direction of the rotating shaft 2, each is arranged along the tangential direction of the rotation direction, the N poles and S poles of each are arranged radially around the rotation center line A of the rotating shaft 2, and the magnetization direction of each is opposite to the magnetization direction of the magnets on both sides of the magnet among the plurality of magnets 86a to 86j. The dimension in the extending direction of the rotation center line of each of the one or more magnets 86b to 86j among the plurality of magnets 86a to 86j is the specified dimension, and the dimension in the extending direction of the rotation center line of the one or more magnets 86a other than the one or more first magnets 86b to 86j is different from the specified dimension.

[0117] Accordingly, since the dimension in the extending direction of the rotation center line of the one or more magnets 86a other than the one or more first magnets 86b to 86j among the plurality of magnets 86a to 86j is different from the specified dimension, the magnitude of the magnetic flux of the magnet 86a can be made different from the magnitude of the magnetic flux of each of the one or more first magnets 86b to 86j, and the one or more periods F1 can be made different from the first specified period. Thus, the mechanical angle of the rotating shaft 2 can be detected easily and with better accuracy, and the torque ripple can be suppressed easily and more appropriately.

[0118] (Fifth Embodiment)

[0119] Figure 11 FIG. is a view showing the magnetic field generating portion 102 and the magnetic core 110 of the torque ripple suppression device according to the fifth embodiment. Figure 11 FIG. shows the magnetic field generating portion 102 and the magnetic core 110 as viewed from the extending direction of the rotation center line.

[0120] The torque ripple suppression device according to the fifth embodiment is mainly different from the torque ripple suppression device 10 in that it includes a magnetic field generating portion 102 instead of the magnetic field generating portion 12. Hereinafter, the differences from the magnetic field generating portion 12 will be mainly described.

[0121] The magnetic field generating portion 102 generates a magnetic field. The magnetic field generating portion 102 generates a magnetic field in a manner that satisfies the following condition (1), and the details will be described later.

[0122] Condition (1): Each of one or more first periods among the periods of the high level in the pulse signal becomes a first specified period, and each of one or more second periods other than the one or more first periods is different from the first specified period.

[0123] The pulse signal shown in this condition (1) is a pulse signal generated during one rotation of the rotating shaft 2 at a constant speed. As Figure 11 shown, the magnetic field generating unit 102 includes one or more magnets 106a to 106j, a plurality of insulators 108a to 108t, and a magnetic core 110. The one or more magnets 106a to 106j are a plurality of magnets 106a to 106j.

[0124] The plurality of magnets 106a to 106j are arranged around the rotation center line A. The plurality of magnets 106b to 106j are arranged along the rotation direction of the rotating shaft 2. The plurality of magnets 106b to 106j are arranged at equal intervals along the rotation direction of the rotating shaft 2. The magnet 106a and the magnet 106b are arranged in a direction intersecting the rotation direction. The magnet 106a and the magnet 106j are arranged in a direction intersecting the rotation direction.

[0125] The plurality of magnets 106a to 106j are each arranged along the tangential direction. That is, the plurality of magnets 106a to 106j are each linear along the tangential direction. In the present embodiment, the plurality of magnets 106a to 106j are each plate-shaped and are arranged such that the thickness direction of the magnet coincides with the radial direction.

[0126] The N poles and S poles of the plurality of magnets 106a to 106j are arranged along the radial direction. The magnetization directions of the plurality of magnets 106a to 106j are opposite to the magnetization directions of the magnets on both sides of the magnet among the plurality of magnets 106a to 106j. That is, the direction in which the N poles and S poles of the plurality of magnets 106a to 106j are arranged is opposite to the direction in which the N poles and S poles of the magnets on both sides of the magnet among the plurality of magnets 106a to 106j are arranged. For example, the direction in which the N pole and S pole of the magnet 106a are arranged is opposite to the direction in which the N pole and S pole of the magnet 106b adjacent to the magnet 106a are arranged, and is opposite to the direction in which the N pole and S pole of the magnet 106j adjacent to the magnet 106a are arranged.

[0127] The radial positions of one or more of the plurality of magnets 106a to 106j, i.e., magnets 106b to 106j, are positions at a predetermined distance from the rotation center line A, and the radial positions of one or more of the magnets 106a other than one or more of the magnets 106b to 106j are different from the positions at a predetermined distance from the rotation center line A. That is, the radial positions of one or more of the magnets 106b to 106j are equal to each other. The radial position of the magnet 106a is a position closer to the rotation center line A than the position at a predetermined distance from the rotation center line A. It should be noted that the radial position of the magnet 106a may also be a position farther from the rotation center line A than the position at a predetermined distance from the rotation center line A. In the present embodiment, one or more of the magnets 106b to 106j are an example of one or more first magnets. In addition, one or more of the magnets 106a are an example of one or more second magnets.

[0128] The dimensions of the plurality of magnets 106b to 106j in the tangential direction are equal to each other. In addition, the dimension of the magnet 106a in the tangential direction is smaller than the dimensions of the plurality of magnets 106b to 106j in the tangential direction. In addition, the radial dimensions of the plurality of magnets 106a to 106j are equal to each other. In addition, the dimensions of the plurality of magnets 106a to 106j in the direction in which the rotation center line extends are equal to each other.

[0129] Figure 12 It is a diagram showing an example of a pulse signal generated by Figure 11 the torque ripple suppression device. Figure 12 It shows an example of a pulse signal generated during the period when the rotating shaft 2 rotates at a constant speed.

[0130] As Figure 12 shown, one or more of the high-level periods G1 to G5 in the pulse signal, i.e., periods G2 to G5, each become a first predetermined period, and one or more of the periods G1 other than one or more of the periods G2 to G5 are different from the first predetermined period. That is, one or more of the periods G2 to G5 are equal to each other. The period G1 is shorter than the first predetermined period. In the present embodiment, one or more of the periods G2 to G5 are an example of one or more first periods. In addition, one or more of the periods G1 are an example of one or more second periods.

[0131] Thus, since the radial position of the magnet 106a is a position closer to the rotation center line A than the position at a predetermined distance from the rotation center line A, the magnitude of the magnetic flux of the magnet 106a detected by the magnetic sensor 22 is smaller than the magnitudes of the magnetic fluxes of one or more of the magnets 106b to 106j, and the period G1 is shorter than the first predetermined period.

[0132] In the torque ripple suppression device according to the fifth embodiment, one or more magnets 106a to 106j are a plurality of magnets 106a to 106j. The plurality of magnets 106a to 106j are arranged around the rotation center line A of the rotation shaft 2, and are each arranged along the tangential direction of the rotation direction of the rotation shaft 2. Their N poles and S poles are arranged radially around the rotation center line A, and their magnetization directions are opposite to the magnetization directions of the magnets on both sides of the magnet among the plurality of magnets 106a to 106j. The radial positions of one or more of the magnets 106b to 106j among the plurality of magnets 106a to 106j are positions at a specified distance from the rotation center line A, and the radial positions of one or more of the magnets 106a other than one or more of the magnets 106b to 106j are different from the positions at a specified distance from the rotation center line A.

[0133] Accordingly, since the radial positions of one or more of the magnets 106a other than one or more of the first magnets 106b to 106j among the plurality of magnets 106a to 106j are different from the positions at a specified distance from the rotation center line A, the magnitude of the magnetic flux of the magnet 106a detected by the magnetic sensor 22 can be made different from the magnitudes of the magnetic fluxes of one or more of the magnets 106b to 106j, and one or more of the periods G1 can be made different from the first specified period. Thus, the mechanical angle of the rotation shaft 2 can be detected easily and with better accuracy, and the torque ripple can be suppressed easily and more appropriately.

[0134] (Sixth embodiment)

[0135] Figure 13 FIG. is a diagram showing the magnetic field generating portion 122 and the magnetic core 130 of the torque ripple suppression device according to the sixth embodiment. Figure 13 FIG. shows the magnetic field generating portion 122 and the magnetic core 130 as viewed from the extending direction of the rotation center line. Figure 14 FIG. shows Figure 13 a perspective view of the magnetic field generating portion 122 of the torque ripple suppression device.

[0136] The torque ripple suppression device according to the sixth embodiment mainly differs from the torque ripple suppression device 10 in that it includes a magnetic field generating portion 122 instead of the magnetic field generating portion 12. Hereinafter, the differences from the magnetic field generating portion 12 will be mainly described.

[0137] The magnetic field generating portion 122 generates a magnetic field. The magnetic field generating portion 122 generates a magnetic field in such a manner as to satisfy the following condition (1), and the details will be described later.

[0138] Condition (1): One or more of the first periods among the plurality of high-level periods in the pulse signal each become a first specified period, and one or more of the second periods other than one or more of the first periods are each different from the first specified period.

[0139] The pulse signal shown in the condition (1) is a pulse signal generated during one revolution of the rotating shaft 2 at a constant speed. As Figure 13 and Figure 14 shown, the magnetic field generating unit 122 includes one or more magnets 126a to 126j, a plurality of insulators 128a to 128t, and a magnetic core 130. The one or more magnets 126a to 126j are a plurality of magnets 126a to 126j.

[0140] The plurality of magnets 126a to 126j are arranged in the rotational direction. The plurality of magnets 126a to 126j are arranged at equal intervals in the rotational direction of the rotating shaft 2.

[0141] The plurality of magnets 126a to 126j are each arranged along the tangential direction of the rotational direction. That is, the plurality of magnets 126a to 126j are each linear along the tangential direction of the rotational direction. In the present embodiment, the plurality of magnets 126a to 126j are each plate-shaped and are arranged such that the thickness direction of the magnet coincides with the radial direction.

[0142] The N poles and S poles of the plurality of magnets 126a to 126j are arranged in the radial direction. The magnetization directions of the plurality of magnets 126a to 126j are opposite to the magnetization directions of the magnets on both sides of the magnet among the plurality of magnets 126a to 126j. That is, the directions in which the N poles and S poles of the plurality of magnets 126a to 126j are arranged are opposite to the directions in which the N poles and S poles of the magnets on both sides of the magnet among the plurality of magnets 126a to 126j are arranged. For example, the directions in which the N pole and S pole of the magnet 126a are arranged are opposite to the directions in which the N pole and S pole of the magnet 126b adjacent to the magnet 126a are arranged, and are opposite to the directions in which the N pole and S pole of the magnet 126j adjacent to the magnet 126a are arranged.

[0143] The magnetic field generating unit 122 has a magnetic shielding member 132 that is not arranged on the outer side in the radial direction of each of the one or more magnets 126b to 126j not arranged among the plurality of magnets 126a to 126j and is arranged on the outer side in the radial direction of one or more magnets 126a other than the one or more magnets 126b to 126j. In the present embodiment, the one or more magnets 126b to 126j are an example of one or more first magnets. In addition, the one or more magnets 126a are an example of one or more second magnets.

[0144] The dimensions in the tangential direction of the plurality of magnets 126a to 126j are equal to each other. In addition, the dimensions in the radial direction of the plurality of magnets 126a to 126j are equal to each other. In addition, the dimensions in the direction in which the rotation center lines of the plurality of magnets 126a to 126j extend are equal to each other.

[0145] Figure 15 It shows byFigure 13 A diagram of an example of a pulse signal generated by a torque fluctuation suppression device. Figure 15 Shows an example of a pulse signal generated during the constant-speed rotation of the rotating shaft 2.

[0146] As Figure 15 shown, one or more of the high-level periods H2 to H5 in the pulse signal each become a first specified period, and one or more of the periods H1 other than the one or more periods H2 to H5 are different from the first specified period. That is, one or more of the periods H2 to H5 are equal to each other. The period H1 is shorter than the first specified period. In the present embodiment, one or more of the periods H2 to H5 are an example of one or more first periods. In addition, one or more of the periods H1 are an example of one or more second periods.

[0147] In this way, by arranging the magnetic shielding member 132 on the outer side in the radial direction of the magnet 126a, the magnitude of the magnetic flux of the magnet 126a detected by the magnetic sensor 22 is smaller than the magnitude of the magnetic flux of each of the one or more magnets 126b to 126j, and the period H1 is shorter than the first specified period.

[0148] In the torque fluctuation suppression device of the sixth embodiment, the one or more magnets 126a to 126j are a plurality of magnets 126a to 126j. The plurality of magnets 126a to 126j are arranged along the rotation direction of the rotating shaft 2, each is arranged along the tangential direction of the rotation direction, the N pole and the S pole of each are arranged radially around the rotation center line A of the rotating shaft 2, and the magnetization direction of each is opposite to the magnetization direction of the magnets on both sides of the magnet among the plurality of magnets 126a to 126j. The magnetic field generating unit 122 has a magnetic shielding member 132 that is not arranged on the outer side in the radial direction of each of the one or more magnets 126b to 126j and is arranged on the outer side in the radial direction of one or more magnets 126a other than the one or more magnets 126b to 126j.

[0149] Accordingly, since the magnetic shielding member 132 is arranged on the outer side in the radial direction of the magnet 126a, it is possible to make the magnitude of the magnetic flux of the magnet 126a detected by the magnetic sensor 22 different from the magnitude of the magnetic flux of each of the one or more magnets 126b to 126j, and it is possible to make one or more of the periods H1 different from the first specified period. Therefore, it is possible to easily and more accurately detect the mechanical angle of the rotating shaft 2, and it is possible to easily and more appropriately suppress torque fluctuations.

[0150] (Seventh Embodiment)

[0151] Figure 16 A diagram showing the magnetic field generating unit 42, the magnetic core 50, and the stator 4 of the torque fluctuation suppression device of the seventh embodiment. Figure 16The magnetic field generating portion 42, the magnetic core 50, and the stator 4 are shown as viewed from the extending direction of the rotation center line. As Figure 16 shown, in the present embodiment, the magnetic field generating portion 42 also serves as the rotor of the motor 1. That is, in the present embodiment, the magnetic field generating portion 42 is used instead of the rotor 3 of the motor 1. By flowing a current through the coil 5 of the stator 4, the magnetic field generating portion 42 rotates relative to the stator 4 together with the rotating shaft 2. For example, the magnetic sensor 22 is disposed on the stator 4.

[0152] In the torque ripple suppressing device of the seventh embodiment, the magnetic field generating portion 42 also serves as the rotor of the motor 1.

[0153] Accordingly, it is possible to rotate the rotating shaft 2 by using the magnetic field generating portion 42 without separately providing a rotor.

[0154] (Eighth Embodiment)

[0155] Figure 17 FIG. is a diagram showing the magnetic field generating portion 142 and the magnetic core 150 of the torque ripple suppressing device of the eighth embodiment. Figure 17 The magnetic field generating portion 142 and the magnetic core 150 are shown as viewed from the extending direction of the rotation center line.

[0156] The torque ripple suppressing device of the eighth embodiment mainly differs from the torque ripple suppressing device 10 in that it includes the magnetic field generating portion 142 instead of the magnetic field generating portion 12. Hereinafter, the differences from the magnetic field generating portion 12 will be mainly described.

[0157] The magnetic field generating portion 142 generates a magnetic field. The magnetic field generating portion 142 generates a magnetic field in such a manner as to satisfy the following condition (1) and condition (2), the details of which will be described later.

[0158] Condition (1): Each of one or more first periods among the high-level periods in the pulse signal becomes a first specified period, and each of one or more second periods other than the one or more first periods is different from the first specified period.

[0159] Condition (2): Each of one or more third periods among the low-level periods in the pulse signal becomes a second specified period, and each of one or more fourth periods other than the one or more third periods is different from the second specified period.

[0160] The pulse signal shown in this condition (1) and this condition (2) is a pulse signal generated during one rotation of the rotating shaft 2 at a constant speed. As Figure 17 shown, the magnetic field generating portion 142 has one or more magnets 146a to 146j and a magnetic core 150. The one or more magnets 146a to 146j are a plurality of magnets 146a to 146j.

[0161] A plurality of magnets 146a to 146j rotate together with the rotating shaft 2 of the motor 1. In the present embodiment, the plurality of magnets 146a to 146j are mounted on the rotating shaft 2 by means of a magnetic core 150 and rotate together with the rotating shaft 2. The plurality of magnets 146a to 146j are attached to the outer surface of the magnetic core 150.

[0162] The plurality of magnets 146a to 146j are arranged in the rotational direction. The plurality of magnets 146c to 146j are arranged at equal intervals in the rotational direction of the rotating shaft 2.

[0163] The plurality of magnets 146a to 146j are each arranged along the rotational direction. That is, the plurality of magnets 146a to 146j are each in a curved shape along the rotational direction. In the present embodiment, the plurality of magnets 146a to 166j are each in a bent plate shape and are arranged such that the thickness direction of the magnet coincides with the radial direction.

[0164] The N poles and S poles of each of the plurality of magnets 146a to 146j are arranged radially. The magnetization direction of each of the plurality of magnets 146a to 146j is opposite to the magnetization directions of the magnets on both sides of the magnet among the plurality of magnets 146a to 146j. That is, the direction in which the N poles and S poles of each of the plurality of magnets 146a to 146j are arranged is opposite to the direction in which the N poles and S poles of the magnets on both sides of the magnet among the plurality of magnets 146a to 146j are arranged. For example, the direction in which the N poles and S poles of the magnet 146a are arranged is opposite to the direction in which the N poles and S poles of the magnet 146b adjacent to the magnet 146a are arranged and is opposite to the direction in which the N poles and S poles of the magnet 146j adjacent to the magnet 146a are arranged.

[0165] The dimensions of one or more of the magnets 146c to 146j among the plurality of magnets 146a to 146j in the rotational direction are a specified dimension, and the dimensions of one or more of the magnets 146a, 146b other than one or more of the magnets 146c to 146j in the rotational direction are different from the specified dimension. That is, the dimensions of one or more of the magnets 146c to 146j in the rotational direction are equal to each other. The dimension of the magnet 146a in the rotational direction is larger than the specified dimension, and the dimension of the magnet 146b in the rotational direction is smaller than the specified dimension. In the present embodiment, one or more of the magnets 146c to 146j are an example of one or more first magnets. In addition, one or more of the magnets 146a, 146b are an example of one or more second magnets.

[0166] The radial dimensions of the plurality of magnets 146a to 146j are equal to each other. In addition, the dimensions of the plurality of magnets 146a to 146j in the extending direction of the rotation center line are equal to each other.

[0167] The magnetic core 150 is formed by laminating a plurality of electromagnetic steel plates. For example, the electromagnetic steel plate is a silicon steel plate. The magnetic core 150 is fixed to the rotating shaft 2. A plurality of magnets 146a to 146j are attached to the outer surface of the magnetic core 150.

[0168] In the present embodiment, for example, a Figure 4 pulse signal as shown is generated.

[0169] In this way, since the dimension of the magnet 146a in the rotation direction is larger than the specified dimension, the period B1 is longer than the first specified period, and the period C5 is longer than the second specified period. In addition, since the dimension of the magnet 146b in the rotation direction is smaller than the specified dimension, the period C1 is shorter than the second specified period.

[0170] In the torque ripple suppression device of the eighth embodiment, one or more of the magnets 146a to 146j are the plurality of magnets 146a to 146j. The plurality of magnets 146a to 146j are arranged along the rotation direction of the rotating shaft 2, each arranged along the rotation direction, and their N poles and S poles are arranged radially around the rotation center line A of the rotating shaft 2, and the magnetization direction of each is opposite to the magnetization directions of the magnets on both sides of the magnet among the plurality of magnets 146a to 146j. The dimensions of one or more of the magnets 146c to 146j among the plurality of magnets 146a to 146j in their respective rotation directions are the specified dimensions, and the dimensions of one or more of the magnets 146a and 146b other than one or more of the magnets 146c to 146j in their respective rotation directions are different from the specified dimension.

[0171] Accordingly, since the dimensions of one or more of the magnets 146a and 146b other than one or more of the magnets 146c to 146j among the plurality of magnets 146a to 146j in their respective rotation directions are different from the specified dimension, one or more of the periods B1 can be made different from the first specified period, and one or more of the periods C1 and C5 can be made different from the second specified period respectively. Thus, the mechanical angle of the rotating shaft 2 can be detected easily and with better accuracy, and the torque ripple can be suppressed easily and more appropriately.

[0172] (Ninth Embodiment)

[0173] Figure 18 FIG. shows the magnetic field generating unit 162 of the torque ripple suppression device of the ninth embodiment. Figure 18 FIG. shows the magnetic field generating unit 162 as viewed from the extending direction of the rotation center line.

[0174] The torque ripple suppression device of the ninth embodiment is mainly different from the torque ripple suppression device 10 in that it includes a magnetic field generating unit 162 instead of the magnetic field generating unit 12.

[0175] In the above-described embodiments, the case where the magnetic field generating unit has a plurality of magnets has been described, but the present invention is not limited thereto. For example, as Figure 18 shown, the magnetic field generating unit 162 may have a single magnet 166 instead of a plurality of magnets 166. For example, the magnet 166 is directly or indirectly mounted on the rotating shaft 2.

[0176] The magnet 166 has a plurality of magnetic poles formed by N poles and S poles alternately arranged in the rotation direction. Among the plurality of magnetic poles, the dimension of one N pole in the rotation direction is different from that of the other N poles. Further, among the plurality of magnetic poles, the dimension of one S pole in the rotation direction is different from that of the other S poles.

[0177] Thus, in the case of using a single magnet 166, it is sufficient that the dimension of the rotation direction of at least one of more than one N pole and more than one S pole is different from that of the other more than one like poles.

[0178] (Other Embodiments, etc.)

[0179] As described above, as an example of the technology disclosed in the present application, the embodiments have been described. However, the technology based on the present invention is not limited to these, and can also be applied to embodiments or modified examples that have been appropriately changed, replaced, added, omitted, etc., as long as the gist of the present invention is not deviated from.

[0180] In addition, the whole or a specific mode of the present invention can be implemented by a system, a device, a method, an integrated circuit, a computer program, or a recording medium such as a computer-readable CD-ROM. Further, it can also be implemented by any combination of a system, a device, a method, an integrated circuit, a computer program, and a recording medium.

[0181] In the above-described second embodiment, the case where the plurality of magnets 46a to 46j are each arranged along the tangential direction has been described, but the present invention is not limited thereto. For example, in the second embodiment, the plurality of magnets may each be arranged along the rotation direction. The same applies to the third to seventh embodiments.

[0182] Industrial Applicability

[0183] The torque ripple suppressing device of the present invention can be used in a device for suppressing torque ripple.

[0184] Description of Reference Numerals

[0185] 1 Motor

[0186] 2 Rotating Shaft

[0187] 3 Rotor

[0188] 4 Stator

[0189] 5 Coils

[0190] 6 Current control unit

[0191] 7 Inverter

[0192] 10 Torque ripple suppression device

[0193] 12, 42, 62, 82, 102, 122, 142, 162 Magnetic field generation unit

[0194] 14 Control board

[0195] 16a~16j, 46a~46j, 66a~66j, 86a~86j, 106a~106j, 126a~126j, 146a~146j, 166 Magnets

[0196] 18a~18t, 48a~48t, 68a~68t, 88a~88t, 108a~108t, 128a~128t Insulators

[0197] 20, 50, 70, 90, 110, 130, 150 Magnetic cores

[0198] 22 Magnetic sensor

[0199] 24 Mechanical angle detection unit

[0200] 26 Torque ripple compensation unit

[0201] 28 Cogging effect compensation unit

[0202] 30 Adder

[0203] 32 Adder

[0204] 72 Holes

[0205] 132 Magnetic shield

Claims

1. A torque ripple suppression device, wherein, the torque ripple suppression device includes: a magnetic field generation unit having one or more magnets that rotate together with a rotation shaft of a motor; a signal generation unit that generates a pulse signal based on a magnetic field that changes as the magnet rotates together with the rotation shaft; a mechanical angle detection unit that detects a mechanical angle of the rotation shaft based on the pulse signal generated by the signal generation unit; and a parameter determination unit that determines a parameter for suppressing torque ripple of the motor based on the mechanical angle detected by the mechanical angle detection unit, the magnetic field generation unit generates the magnetic field in a manner that satisfies at least one of the following condition (1) and condition (2), Condition (1): Each of one or more first periods among a plurality of high-level periods in the pulse signal becomes a first specified period, and each of one or more second periods other than the first periods is different from the first specified period; Condition (2): Each of one or more third periods among a plurality of low-level periods in the pulse signal becomes a second specified period, and each of one or more fourth periods other than the third periods is different from the second specified period.

2. The torque ripple suppression device according to claim 1, wherein, the one or more magnets are a plurality of magnets, the plurality of magnets are arranged and configured around a rotation center line of the rotation shaft, each is arranged along a tangential direction of the rotation direction of the rotation shaft, the N pole and the S pole of each are arranged radially around the rotation center line, and the magnetization direction of each is opposite to the magnetization directions of the magnets on both sides of the magnet among the plurality of magnets; the size of each of one or more first magnets among the plurality of magnets in the tangential direction is a specified size, and the size of each of one or more second magnets other than the first magnets in the tangential direction is different from the specified size.

3. The torque ripple suppression device according to claim 1, wherein, the magnet is a plurality of magnets, the plurality of magnets are arranged and configured along the rotation direction of the rotation shaft, each is arranged along the rotation direction, the N pole and the S pole of each are arranged radially around the rotation center line of the rotation shaft, and the magnetization direction of each is opposite to the magnetization directions of the magnets on both sides of the magnet among the plurality of magnets; the size of each of one or more first magnets among the plurality of magnets in the rotation direction is a specified size, and the size of each of one or more second magnets other than the first magnets in the rotation direction is different from the specified size.

4. The torque ripple suppression device according to claim 1, wherein, the magnet is a plurality of magnets, the plurality of magnets are arranged and configured along the rotation direction of the rotation shaft, each is arranged along the tangential direction or the rotation direction of the rotation direction, the N pole and the S pole of each are arranged radially around the rotation center line of the rotation shaft, and the magnetization direction of each is opposite to the magnetization directions of the magnets on both sides of the magnet among the plurality of magnets; The magnitude of the magnetic flux of each of one or more first magnets among the plurality of magnets is a specified magnitude, and the magnitude of the magnetic flux of each of one or more second magnets other than the first magnets is different from the specified magnitude.

5. The torque ripple suppressing device according to claim 1, wherein the magnet is a plurality of magnets, the plurality of magnets are arranged and configured along the rotation direction of the rotation axis, each is arranged along the tangential direction or the rotation direction of the rotation direction, the N pole and the S pole of each are arranged radially around the rotation center line of the rotation axis, and the magnetization direction of each is opposite to the magnetization directions of the magnets on both sides of the magnet among the plurality of magnets. One or more first magnets among the plurality of magnets are each not provided with a hole, and one or more second magnets other than the first magnets are each provided with a hole.

6. The torque ripple suppressing device according to claim 1, wherein the magnet is a plurality of magnets, the plurality of magnets are arranged and configured along the rotation direction of the rotation axis, each is arranged along the tangential direction or the rotation direction of the rotation direction, the N pole and the S pole of each are arranged radially around the rotation center line of the rotation axis, and the magnetization direction of each is opposite to the magnetization directions of the magnets on both sides of the magnet among the plurality of magnets. The dimension of the extension direction of the rotation center line of each of one or more first magnets among the plurality of magnets is a specified dimension, and the dimension of the extension direction of each of one or more second magnets other than the first magnets is different from the specified dimension.

7. The torque ripple suppressing device according to claim 1, wherein the magnet is a plurality of magnets, the plurality of magnets are arranged and configured around the rotation center line of the rotation axis, each is arranged along the tangential direction or the rotation direction of the rotation axis, the N pole and the S pole of each are arranged radially around the rotation center line, and the magnetization direction of each is opposite to the magnetization directions of the magnets on both sides of the magnet among the plurality of magnets. The radial position of each of one or more first magnets among the plurality of magnets is a position at a specified distance from the rotation center line, and the radial position of each of one or more second magnets other than the first magnets is different from the position at the specified distance from the rotation center line.

8. The torque ripple suppressing device according to claim 1, wherein the magnet is a plurality of magnets, the plurality of magnets are arranged and configured along the rotation direction of the rotation axis, each is arranged along the tangential direction or the rotation direction of the rotation direction, the N pole and the S pole of each are arranged radially around the rotation center line of the rotation axis, and the magnetization direction of each is opposite to the magnetization directions of the magnets on both sides of the magnet among the plurality of magnets. The magnetic field generating portion has a magnetic shielding member that is not disposed on the outer side in the radial direction of each of one or more first magnets among the plurality of magnets, and is disposed on the outer side in the radial direction of each of one or more second magnets other than the first magnets.

9. The torque ripple suppression device according to any one of claims 1 to 8, wherein the magnetic field generation unit also serves as the rotor of the motor.

10. The torque ripple suppression device according to any one of claims 1 to 8, wherein the magnetic field generation unit is mounted on the front end portion of the rotating shaft.

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