Magnetic gear device

Abstract

This magnetic gear device (100) comprises: a magnetic gear (20) which has an inner magnet barrel (23) that is a few-pole mechanism, an outer magnet barrel (26) that is a multi-pole mechanism, and pole pieces (29) disposed at equal circumferential intervals between the inner magnet barrel (23) and the outer magnet barrel (26), and in which one among the inner magnet barrel (23), the outer magnet barrel (26), and the pole pieces (29) serves as a first rotor connected to an input part (21), another serves as a second rotor connected to an output part (22), and the remaining one serves as a stator; and a rotary electric machine (10) comprising a rotor (12) having a permanent magnet (13) and a stator (15) having teeth (16). Satisfied is at least one among: a first condition in which a first numerical value based on the least common multiple of the number of pole pieces (29) and the number of poles of one among the first and second rotors coincides with the least common multiple of the number of poles of the rotor (12) and the number of teeth (16); and a second condition in which the first numerical value coincides with a number obtained by multiplying a multiple of three to the number of poles of the rotor (12).

Description

Technical Field

[0001] The present application relates to a magnetic gear device.

Background Art

[0002] In recent years, in order to obtain desired output and efficiency characteristics from a rotating electrical machine, a magnetic gear is used in combination with the rotating electrical machine. The magnetic gear that constitutes a conventional magnetic gear device includes a cylindrical inner magnet cylinder having a plurality of magnets arranged in parallel on the outer periphery, a cylindrical outer magnet cylinder having a plurality of magnets arranged in parallel on the inner periphery, and a plurality of magnetic bodies arranged in parallel at equal intervals in the circumferential direction. The cylindrical magnetic body cylinder is coaxially supported with the magnetic body cylinder interposed between the inner magnet cylinder and the outer magnet cylinder, and any two of the inner magnet cylinder, the outer magnet cylinder, and the magnetic body cylinder are used as a rotor, and the remaining one is used as a stator to transmit rotational torque. The magnetic body has a rod shape extending parallel to the axial length direction of the magnetic body cylinder, and the magnets of the inner magnet cylinder and the outer magnet cylinder are skewed with a positional shift in the same direction in each circumferential direction between one end and the other end in the axial length direction. Thereby, while ensuring a high torque density, the cogging torque can be effectively reduced, and stable power transmission under small torque fluctuations can be realized.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the conventional magnetic gear described in Patent Document 1, it is necessary to continuously skew the permanent magnet in the axial direction, and it cannot be easily manufactured. Further, although torque pulsation can be reduced as a single magnetic gear, there is a problem that speed vibration caused by torque pulsation of the rotating electrical machine also occurs on the output side of the magnetic gear.

[0005] This application discloses a technology for solving the above problems, and an object thereof is to provide a magnetic gear device that can reduce torque pulsation output from a combination of a magnetic gear and a rotating electric machine and suppress speed vibration on the output side. Furthermore, it is an object to manufacture such a magnetic gear device easily and inexpensively.

Means for Solving the Problems

[0006] The magnetic gear device disclosed in this application includes an inner magnet cylinder in which a plurality of first permanent magnets are arranged on the outer periphery to form a multi-pole mechanism, an outer magnet cylinder in which a plurality of second permanent magnets are arranged on the inner periphery to form a multi-pole mechanism, and a magnetic body cylinder disposed between the inner magnet cylinder and the outer magnet cylinder with a magnetic gap therebetween, and having N pole pieces made of a soft magnetic material arranged at equal intervals in the circumferential direction. Inside the inner magnet cylinder, the outer magnet cylinder, and the magnetic body cylinder, there are a first rotor connected to an input part, a second rotor connected to an output part, and a magnetic gear using the remaining one as a stator, a rotor having M1 permanent magnets, and a rotating electric machine including a stator having M2 teeth. The input part of the magnetic gear is connected to the rotating shaft of the rotating electric machine, and transmits the input rotational force to the output part. And, a first numerical value based on the least common multiple of the number N of the pole pieces and the number of poles of one of the first and second rotors satisfies at least one of a first condition that it coincides with the least common multiple M of M1 and M2, and a second condition that it coincides with a number obtained by multiplying M1 by a multiple of 3.

Effects of the Invention

[0007] According to the magnetic gear device disclosed in this application, torque pulsation output from a combination of a magnetic gear and a rotating electric machine can be reduced, and speed vibration on the output side can be suppressed. Also, such a magnetic gear device can be manufactured easily and inexpensively.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Figure 16

Figure 17

Figure 18

Figure 19

Mode for Carrying Out the Invention

[0009] Embodiment 1. FIG. 1 is a longitudinal sectional view showing the configuration of the magnetic gear device according to Embodiment 1. As shown in FIG. 1, the magnetic gear device 100 is composed of a drive unit including a rotational electric machine 10 and a magnetic gear 20. FIG. 2 is a cross-sectional view showing the configuration of the rotational electric machine 10 in the magnetic gear device 100, showing the A-A cross-section of FIG. 1. FIG. 3 is a cross-sectional view showing the configuration of the magnetic gear 20 in the magnetic gear device 100, showing the B-B cross-section of FIG. 1.

[0010] As shown in the figure, the shaft serving as the rotation shaft 11 of the rotational electric machine 10 is connected to the input portion 21 of the magnetic gear 20, and the magnetic gear 20 transmits the rotational force input to the input portion 21 to the output portion 22. In this case, the input portion 21 of the magnetic gear 20 is integrally formed with the rotation shaft 11 of the rotational electric machine 10. The rotational electric machine 10 includes a rotor 12 and a stator 15 provided via a magnetic gap on the outer periphery of the rotor 12.

[0011] The rotor 12 is composed of a plurality (M1 pieces), in this case 8 permanent magnets 13 that carry magnetic poles, arranged side by side in the circumferential direction on the outer peripheral surface of the rotor core 14. The permanent magnets 13 are magnetized in the radial direction and are arranged such that the polarities of the adjacent permanent magnets 13 are reversed. The stator 15 has a plurality (M2, in this case 12) of teeth 16 protruding toward the magnetic gap, and coils 17 are wound around each of the teeth 16. Thus, the rotating electrical machine 10 is an example of an 8-pole 12-slot concentrated winding structure having 8 permanent magnets 13 and 12 teeth 16. Note that the illustration of the coils 17 in FIG. 2 is omitted for convenience.

[0012] The magnetic gear 20 includes an inner magnet cylinder 23 constituting a low-pole mechanism with a small number of magnetic poles, an outer magnet cylinder 26 constituting a multi-pole mechanism with a large number of magnetic poles, and a magnetic body cylinder 30 disposed between the inner magnet cylinder 23 and the outer magnet cylinder 26 with a magnetic gap 31 therebetween on both sides. The inner magnet cylinder 23 is formed by arranging a plurality, in this case 8, of first permanent magnets 25 carrying magnetic poles in parallel in the circumferential direction on the outer peripheral surface of a cylindrical support 24. The first permanent magnets 25 are magnetized in the radial direction, and are arranged such that the polarities of the first permanent magnets 25 adjacent to each other are reversed. The outer magnet cylinder 26 is formed by arranging a plurality, in this case 40, of second permanent magnets 28 carrying magnetic poles in parallel in the circumferential direction on the inner peripheral surface of a cylindrical support 27. The second permanent magnets 28 are magnetized in the radial direction, and are arranged such that the polarities of the second permanent magnets 28 adjacent to each other are reversed. The magnetic body cylinder 30 disposed between the inner magnet cylinder 23 and the outer magnet cylinder 26 is composed of N, in this case 24, pole pieces 29 made of a soft magnetic material, which are arranged at equal intervals in the circumferential direction.

[0013] In the rotating electrical machine 10 and the magnetic gear 20, the portions (hatched portions in FIG. 1) that generate driving force and gear action respectively are made of a magnetic material. This portion is protected by frames (rotating electrical machine frame 18, magnetic gear frame 32) and brackets (rotating electrical machine bracket 19, magnetic gear bracket 33) made of structural members such as iron or non-magnetic bodies.

[0014] The magnetic gear 20 concentrically arranges an inner magnet cylinder 23, an outer magnet cylinder 26, and a magnetic body cylinder 30. Among these three components, one is a first rotor connected to the input section 21, another is a second rotor connected to the output section 22, and the remaining one is used as a stator. Note that not only the first and second permanent magnets 25 and 28 of the magnetic gear 20, but also N pole pieces 29 made of soft magnetic material are referred to as the magnetic poles of the rotor or the stator. In this embodiment, the inner magnet cylinder 23 is used as the first rotor, the outer magnet cylinder 26 is used as the second rotor, and the magnetic body cylinder 30 is used as the stator. The rotor 12 of the rotating electrical machine 10, the first rotor (inner magnet cylinder 23) of the magnetic gear 20, and the second rotor (outer magnet cylinder 26) of the magnetic gear 20 are supported by a plurality of bearings 35.

[0015] That is, in this embodiment, the rotor 12 of the rotating electrical machine 10 and the first rotor (inner magnet cylinder 23) of the magnetic gear 20 are provided coaxially, and the first rotor (inner magnet cylinder 23) of the magnetic gear 20 rotates together with the rotating shaft 11 of the rotating electrical machine 10. The first permanent magnet 25 of the first rotor (inner magnet cylinder 23) rotates so as to sequentially cross the pole pieces 29 of the magnetic body cylinder 30 which is the stator, and a magnetic force is applied to the second permanent magnet 28 of the second rotor (outer magnet cylinder 26). Then, the second rotor (outer magnet cylinder 26) rotates in the opposite direction to the first rotor (inner magnet cylinder 23).

[0016] The magnetic gear device 100 is configured as described above, and the driving force generated by the rotating electrical machine 10 is decelerated and torque-increased or speeded-up and torque-decreased by the magnetic gear 20, and is output from the output section 22 corresponding to the output shaft of the magnetic gear 20. In this embodiment, a configuration for decelerating and torque-increasing is shown. Since the number of the first permanent magnets 25 of the first rotor (inner magnet cylinder 23) is 8, the number of the second permanent magnets 28 of the second rotor (outer magnet cylinder 26) is 40, and the number of the pole pieces 29 is 24, the gear ratio of the magnetic gear 20 is (40 / 2) / (8 / 2) = 5. That is, the magnetic gear 20 decelerates the rotational force input to the input section 21 to 1 / 5 times and increases the torque to 5 times, and outputs it to the output section 22.

[0017] FIG. 4 is a partial cross-sectional view showing the positional relationship of each part of the magnetic gear 20. In FIG. 4, one of the first permanent magnets 25 of the first rotor (inner magnet cylinder 23) is extracted and illustrated together with the pole piece 29 of the magnetic body cylinder 30. That is, it is a circumferential range of 45° (=(360° / 8)) in terms of mechanical angle (hereinafter referred to as mechanical angle). FIG. 5 is a waveform diagram showing the magnetic gear torque of the magnetic gear device 100. In FIG. 5, the torque waveform of the first rotor (inner magnet cylinder 23) when the first rotor (inner magnet cylinder 23) is rotated 360° in terms of electrical angle (hereinafter referred to as electrical angle), that is, 90° (=(360° / (8 / 2)) in terms of mechanical angle, is shown.

[0018] As shown in FIG. 5, it can be seen that six torque pulsations occur during the rotation of the first rotor (inner magnet cylinder 23) by 360° in electrical angle. This torque pulsation is generated by periodically arranging the pole piece 29, which is a magnetic body, at positions facing the first permanent magnets 25 arranged periodically, and is also called cogging torque. The number of torque pulsations is determined by the relationship between the number of the first permanent magnets 25 and the number of the pole pieces 29. When the first rotor (inner magnet cylinder 23) having the first permanent magnets 25 rotates 360° in mechanical angle, it is generally known as a theory that it becomes a multiple of the least common multiple LCM of the number of the first permanent magnets 25 and the number of the pole pieces 29.

[0019] In this case, LCM(8, 24)=24, and the magnetic gear torque includes a component that vibrates 24K (K is a natural number) times at a mechanical angle of 360°. Therefore, at an electrical angle of 360°, it vibrates 6K(=(24K / (8 / 2)) times, and a component that vibrates 6 times with K = 1 is included a lot, which is consistent with the result shown in FIG. 5. Note that the phase of the torque waveform shown in FIG. 5 is shown with the cross section where the circumferential magnetic pole center position of the first rotor (inner magnet cylinder 23) rotating in the direction of the arrow 40 and the circumferential center position of the pole piece 29 coincide as the initial angle 0°, as indicated by the center line 41 in FIG. 4.

[0020] FIG. 6 is a partial cross-sectional view showing the positional relationship of each part of the rotating electrical machine 10. In FIG. 6, for the circumferential range of one permanent magnet 13 of the rotor 12 of the rotating electrical machine 10 (range of mechanical angle 45°), one rotor core 14, one permanent magnet 13, and one tooth 16 of the stator 15 are extracted and illustrated. In FIG. 6, with reference to the case where the circumferential magnetic pole center position (center line 43) of the rotor 12 rotating in the direction of arrow 42 coincides with the circumferential center position (center line 44) of the tooth 16, the phase shift of the circumferential magnetic pole center position (center line 43) of the rotor 12 from the circumferential center position (center line 44) of the tooth 16 is represented by θ.

[0021] FIG. 7 is a waveform diagram showing the torque of the rotating electrical machine when no current is applied. In FIG. 7, when no current is applied to the coil 17 of the rotating electrical machine 10, the torque waveform of the rotor 12 when the rotor 12 is rotated by 360° electrical degrees, that is, rotated by 90° mechanical degrees (=(360° / (8 / 2)) is shown. Here, the torque waveform without phase shift is shown by a dotted line, and the torque waveform with phase shift θ is shown by a solid line. For the torque waveform without phase shift, the cross-section where the circumferential magnetic pole center position of the rotor 12 and the circumferential center position of the tooth 16 coincide is taken as the initial angle 0°. Also, for the torque waveform with phase shift θ, the cross-section where the circumferential magnetic pole center position of the rotor 12 is shifted from the circumferential center position of the tooth 16 by the phase θ is taken as the initial angle 0°.

[0022] As shown in FIG. 7, the rotating electrical machine torque has torque pulsations with six vibrations as the main component, similar to the magnetic gear torque described above. Regarding the principle of determining the number (order) of vibrations of the rotating electrical machine 10, it is the same as that of the magnetic gear 20 except that the pole pieces 29 arranged periodically correspond to the teeth 16. That is, the number of torque pulsations when the rotor 12 rotates by 360° mechanical degrees is a multiple of the least common multiple M of the number of poles of the rotor 12, which is the number of permanent magnets 13, and the number of teeth 16.

[0023] In this case, the least common multiple M(8, 12) = 24, and the rotating electrical machine torque includes a component that vibrates 24K (K is a natural number) times at a mechanical angle of 360°. Therefore, at an electrical angle of 360°, it vibrates 6K(=(24K / (8 / 2)) times, and there are many components that vibrate 6 times when K = 1, which is consistent with the result shown in FIG. 7.

[0024] In the magnetic gear device 100, the rotor 12 of the rotating electrical machine 10 and the first rotor (inner magnet cylinder 23) of the magnetic gear 20 are connected, and the combined torque of the rotating electrical machine torque and the magnetic gear torque becomes the overall torque. In this embodiment, the least common multiple LCM of the number of the first permanent magnets 25 of the first rotor (inner magnet cylinder 23) of the magnetic gear 20 and the number of the pole pieces 29 coincides with the least common multiple M of the number of poles of the rotor 12 of the rotating electrical machine 10 and the number of teeth 16. That is, the order component of the main torque pulsation per one rotation (mechanical angle 360° rotation) of the first rotor (inner magnet cylinder 23) of the magnetic gear 20 and the order component of the main torque pulsation per one rotation (mechanical angle 360° rotation) of the rotor 12 of the rotating electrical machine 10 both coincide at 24.

[0025] Therefore, the torque pulsation of the rotating electrical machine torque can be reduced by canceling out the torque pulsation of the magnetic gear torque. The torque pulsation varies depending on the relative relationship of the following two positional relationships. One is the positional relationship between the pole piece 29 of the magnetic gear 20 and the tooth 16 of the rotating electrical machine 10. The other is the positional relationship between the permanent magnet 13 of the rotor 12 of the rotating electrical machine 10 and the first permanent magnet 25 of the first rotor (inner magnet cylinder 23) of the magnetic gear 20 to which the rotor 12 of the rotating electrical machine 10 and the shaft (rotating shaft 11) are connected.

[0026] That is, when the circumferential magnetic pole center of the first rotor (inner magnet cylinder 23) coincides with the circumferential magnetic pole center of the stator (magnetic cylinder 30), that is, the circumferential center position of the pole piece 29, by setting the phase θ that shifts the circumferential magnetic pole center of the rotor 12 from the circumferential center position of the tooth 16 as a parameter of the set angle, it becomes possible to define the relative relationship that contributes to the phase of the torque pulsation. Note that the state shown in Fig. 4 is when the circumferential magnetic pole center of the first rotor (inner magnet cylinder 23) coincides with the circumferential center position of the pole piece 29. And in that state, the phase shift θ of the circumferential magnetic pole center position (center line 43) of the rotor 12 from the circumferential center position (center line 44) of the teeth 16 is adjusted (see Fig. 6). Thereby, torque ripple can be effectively reduced and speed vibration caused by torque ripple can be suppressed.

[0027] Fig. 8 is a waveform diagram showing the rotational electrical machine torque, magnetic gear torque, and combined torque when no current is applied in the magnetic gear device 100. In this case, the torque waveform (broken line) of the rotational electrical machine 10, the torque waveform (dotted line) of the magnetic gear 20, and the combined torque waveform (solid line) obtained by adding and combining both are shown when the phase shift θ = 21°. As shown in the figure, the difference (P - P) between the maximum value and the minimum value of the waveform, which is the magnitude Tα of the torque ripple of the combined torque waveform, becomes significantly smaller compared to the torque waveform of the rotational electrical machine 10 and the torque waveform of the magnetic gear 20, and the torque ripple is remarkably reduced.

[0028] Fig. 9 is a waveform diagram showing the change in the torque ripple of the combined torque according to the phase shift θ of the rotor 12 of the rotational electrical machine 10 in the magnetic gear device 100. Here, the phase shift θ is changed within a range of one period of the component that vibrates six times at an electrical angle of 360°, that is, an electrical angle of 60° (= (360 / 6)), which is the main component of the torque ripple in the rotational electrical machine torque and the magnetic gear torque. And the variation of the magnitude (P - P) of the torque ripple according to the phase shift θ is shown. Let Tβ be the smaller of the magnitudes of the torque ripple of the rotational electrical machine torque and the magnitude of the torque ripple of the magnetic gear torque. Referring to Figs. 6 and 7, in this case, Tβ is the magnitude of the torque ripple of the magnetic gear torque and is approximately 5.0.

[0029] As shown in Fig. 9, the torque ripple of the combined torque takes a minimum value Tα around θ = 21° when θ is expressed in electrical angle, and is reduced compared to the torque ripples of the magnetic gear torque and the rotational electrical machine torque within the range of θ (12.3° < θ < 25.5°).

[0030] Next, since the range of the misalignment phase θ with a torque ripple reduction effect varies depending on the configuration such as the shape and arrangement of the permanent magnet of the rotor and the magnetic body (pole piece or teeth, etc.), the range of θ where a reduction effect is generally considered will be examined below. FIG. 10 is a diagram showing the amplitude of the frequency analysis result of the magnetic gear torque in the magnetic gear device 100. FIG. 11 is a diagram showing the amplitude of the frequency analysis result of the rotating electrical machine torque in the magnetic gear device 100.

[0031] As described above, the main components of the torque ripples of the magnetic gear torque and the rotating electrical machine torque include multiple components that are multiples of the least common multiple of the number of permanent magnets (25, 13) and the magnetic body (teeth 16, pole piece 29), and in particular, the 1-fold and 2-fold components are dominant. In this embodiment, since the order of the torque ripple at the electrical angle of 360° is 6K, it can be seen that the 6th order component (K = 1) and the 12th order component (K = 2) are dominant. Also, since it is generally known that these 1-fold (K = 1) and 2-fold (K = 2) order components are dominant in many structures, attention is paid to the reduction of these two components. Note that the magnitude relationship between the two components varies depending on the structures of the rotating electrical machine 10 and the magnetic gear 20.

[0032] FIG. 12 is a waveform diagram showing the 6th order component of the torque in the magnetic gear device 100 in a generalized manner. Here, in the magnetic gear torque and the rotating electrical machine torque, the torque waveforms in which only the 6th order component is extracted and the amplitude is generalized to 1 are shown for an electrical angle of 360°. In this case, the magnitude of the torque ripple TA is 2.0. Also, FIG. 13 is a waveform diagram showing the 12th order component of the torque in the magnetic gear device 100 in a generalized manner. Here, in the magnetic gear torque and the rotating electrical machine torque, the torque waveforms in which only the 12th order component is extracted and the amplitude is generalized to 1 are shown for an electrical angle of 360°. In this case, the magnitude of the torque ripple TB is 2.0.

[0033] In FIGS. 12 and 13, the case where the maximum value of the torque waveform is the initial angle is shown by a dotted line, and the torque waveform in the case having a phase shift by a shift phase θ is shown by a solid line. As described above, in this embodiment, when adding and synthesizing the rotating electrical machine torque and the magnetic gear torque, by adjusting the shift phase θ of the circumferential magnetic pole center position of the rotor 12 from the circumferential center position of the teeth 16, the torque ripple can be effectively reduced. In FIGS. 12 and 13, assuming the torque waveform (dotted line) without phase shift as the magnetic gear torque and the torque waveform (solid line) with phase shift θ as the rotating electrical machine torque, by adding the two, the torque waveforms of the 6th harmonic component and the 12th harmonic component of the synthesized torque can be generated.

[0034] FIG. 14 is a waveform diagram showing the generalization of the torque ripples of the 6th harmonic component and the 12th harmonic component of the synthesized torque in the magnetic gear device 100. In FIG. 14, regarding the synthesized torque of the 6th harmonic component and the synthesized torque of the 12th harmonic component generated based on FIGS. 12 and 13, the change in the torque ripple according to the shift phase θ is shown. Also in this case, within one period of the component that vibrates six times at an electrical angle of 360°, that is, within a range of an electrical angle of 60° (= (360 / 6)), the shift phase θ is changed. Then, the variation in the magnitude (P - P) of the torque ripple according to the shift phase θ is shown.

[0035] The torque ripple of the synthesized torque of the 6th harmonic component is reduced compared to the torque ripples TA, TB (= 2.0) of the torque before synthesis in the range of 20° < θ < 40° when θ is expressed in electrical angle. Also, the torque ripple of the synthesized torque of the 12th harmonic component is reduced compared to the torque ripples TA, TB (= 2.0) of the torque before synthesis in the ranges of 10° < θ < 20° and 40° < θ < 50°. That is, it can be understood that the torque ripple of the synthesized torque of the 6th harmonic component or the 12th harmonic component is reduced compared to the torque ripple of the torque before synthesis in the θ range of 10° < θ < 50°.

[0036] The range of θ (12.3° < θ < 25.5°) shown in FIG. 9 is an example based on the configurations of the rotating electrical machine 10 and the magnetic gear 20 of the magnetic gear device 100 according to this embodiment. Since it is within the above θ range (10° < θ < 50°), it can be explained that a reduction effect appears due to the synthesis.

[0037] In this embodiment, the least common multiple M of the number of poles of the rotor 12 of the rotating electrical machine 10 and the number of teeth 16 is taken as the order of torque pulsation, and the components that vibrate M times and 2M times per 360° mechanical rotation of the rotor 12 can be reduced. Then, when considering the above electrical angle and applying it to the mechanical angle, the range of the misalignment phase φ (: mechanical angle) at which torque pulsation can be reduced is (360 / M / 6)° < φ < ((360 / M / 6)×5))°.

[0038] That is, when the circumferential magnetic pole center of the first rotor (inner magnet cylinder 23) coincides with the circumferential center position of the fixed pole piece 29, if the circumferential magnetic pole center of the rotor 12 has a positional relationship shifted by the range of the phase (mechanical angle) φ of (360 / M / 6)° < φ < ((360 / M / 6)×5))° from the circumferential center position of the teeth 16, the torque pulsation is effectively reduced.

[0039] As described above, in this embodiment, the least common multiple LCM of the number of pole pieces 29 of the magnetic gear 20 and the number of poles of the first rotor (inner magnet cylinder 23) coincides with the least common multiple M of the number of poles of the rotor 12 of the rotating electrical machine 10 and the number of teeth 16. Thereby, the magnetic gear device 100, which is a combination of the magnetic gear 20 and the rotating electrical machine 10, can reduce the output torque pulsation and suppress the speed vibration on the output side. Also, no special processing is required for the first and second permanent magnets 25 and 27 used in the magnetic gear 20, and the magnetic gear device 100 can be manufactured easily and inexpensively.

[0040] Also, when the circumferential magnetic pole center of the first rotor (inner magnet cylinder 23) coincides with the circumferential center position of the fixed pole piece 29, the circumferential magnetic pole center of the rotor 12 is shifted in phase from the circumferential center position of the teeth 16 by a set angle, thereby reducing the torque pulsation of the rotating electrical machine 10 and the torque pulsation of the magnetic gear 20 with respect to each other. As a result, the torque pulsation of the combined torque output from the magnetic gear device 100 is effectively reduced, suppressing the speed vibration on the output side.

[0041] Also, in this embodiment, the number of poles of the first rotor (inner magnet cylinder 23) of the magnetic gear 20 coincides with the number of poles of the rotor 12 of the rotating electrical machine 10. Thereby, it becomes possible to design to use products of the same specifications for the permanent magnet 13 of the rotor 12 of the rotating electrical machine 10 and the first permanent magnet 25 of the first rotor (inner magnet cylinder 23) of the magnetic gear 20, and the manufacturing cost can be reduced.

[0042] Also, in the magnetic gear device 100, usually, from the viewpoints of output and efficiency, first, the required specifications of the rotating electrical machine 10 are determined, and accordingly, the number of poles of the rotor 12 and the number of teeth 16 are determined. Then, the magnetic gear 20 is selected so that the torque pulsation of the magnetic gear torque and the torque pulsation of the rotating electrical machine torque can be reduced by cancellation. That is, the main order of the torque pulsation generated from the magnetic gear 20 is equal to or higher than the order of the torque pulsation generated by the rotating electrical machine 10.

[0043] In the magnetic gear 20, it is desirable that the number of poles of the first rotor (inner magnet cylinder 23) connected to the output shaft of the rotating electrical machine 10 is equal to or more than the number of poles of the rotor 12 of the rotating electrical machine 10. As described above, the order of the torque pulsation of the magnetic gear 20 is dominated by the least common multiple LCM of the number N of pole pieces 29 and the number of poles of the first rotor (inner magnet cylinder 23). For this reason, when the number of poles of the first rotor (inner magnet cylinder 23) is smaller than the number of poles of the rotor 12 of the rotating electrical machine 10, there is a concern that a component of an order smaller than the order component of the torque pulsation generated by the rotating electrical machine 10 may be increased, and the torque pulsation reduction effect may not be obtained as a whole.

[0044] In this embodiment, a magnetic gear device 100 is shown, which combines a magnetic gear 20 including an 8-pole first rotor (inner magnet cylinder 23) constituting a few-pole mechanism, a 40-pole second rotor (outer magnet cylinder 26) constituting a multi-pole mechanism, and 24 pole pieces 29 constituting a magnetic body cylinder 30, and an 8-pole 12-slot rotating electrical machine 10. Generalizing this example, a magnetic gear 20 is considered where, taking X and Y as integers, the number of poles of the first rotor (inner magnet cylinder 23) is 2X, the number of poles of the second rotor (outer magnet cylinder 26) is 2Y, and the number of pole pieces 29 is (X + Y).

[0045] In such a magnetic gear 20, while the first rotor (inner magnet cylinder 23) rotates 360° in electrical angle, that is, (360 / X)° in mechanical angle, the magnetic gear torque vibrates (least common multiple LCM(2X, (X + Y)) / X) times. Therefore, the number of times the magnetic gear torque vibrates while the first rotor (inner magnet cylinder 23) makes one rotation is (LCM(2X, (X + Y)) / X) × (360 / (360 / X)) = LCM(2X, (X + Y)). Thus, it is clear that if the least common multiple M of the number of poles of the rotor 12 and the number of teeth 16 of the rotating electrical machine 10 coincides with the least common multiple LCM of the number of poles of the first rotor (inner magnet cylinder 23) connected to the rotating shaft 11 of the rotating electrical machine 10 and the number of pole pieces 29, adjustment can be made such that the torque pulsation of the magnetic gear torque and the torque pulsation of the rotating electrical machine torque can be reduced by cancellation.

[0046] In the above embodiment, the rotating shaft 11 of the rotating electrical machine 10 was integrally formed with the input portion 21 of the magnetic gear 20, but it is not limited to this. FIG. 15 is a longitudinal sectional view showing the configuration of a magnetic gear device 100 according to another example of Embodiment 1. As shown in FIG. 15, the rotating shaft 11 of the rotating electrical machine 10 is connected to the input portion 21 of the magnetic gear 20 via a rotation force connection mechanism 36 such as a shaft coupling. The connection mechanism 36 may be a belt, a mechanical gear, a magnetic coupling, or the like in addition to the shaft coupling. Thus, even when the rotating shaft 11 of the rotating electrical machine 10 is connected to the input portion 21 of the magnetic gear 20 via the rotational force connection mechanism 36, the same effects as those in the first embodiment can be obtained.

[0047] In addition, in the above-described embodiment, an example in which the pole piece 29 is fixed has been shown. However, the pole piece 29 may be configured to be freely rotatable and capable of arbitrarily adjusting the phase, and the same effects can be obtained.

[0048] Embodiment 2. In the above-described first embodiment, in the magnetic gear device 100, the reduction of torque ripple when no current is applied has been described. In this second embodiment, in the magnetic gear device 100, the reduction of torque ripple when a current is applied to the rotating electrical machine 10 will be described. Note that the structure of the magnetic gear device 100 in this embodiment is the same as the structure shown in FIGS. 1 to 3 of the first embodiment. FIG. 16 is a waveform diagram showing the rotating electrical machine torque, the magnetic gear torque, and the combined torque when a current is applied in the magnetic gear device according to the second embodiment.

[0049] As described above, in the magnetic gear device 100, the rotor 12 of the rotating electrical machine 10 and the first rotor (inner magnet cylinder 23) of the magnetic gear 20 are connected, and the combined torque of the rotating electrical machine torque and the magnetic gear torque becomes the total torque. In FIG. 16, the torque waveform (broken line) of the rotating electrical machine 10 when a current is applied to the coil 17 of the rotating electrical machine 10, the torque waveform (dotted line) of the magnetic gear 20, and the combined torque waveform (solid line) obtained by adding and combining both are shown.

[0050] The magnetic gear torque is the same as the torque waveform shown in FIG. 5 of the first embodiment, that is, six torque ripples occur during one rotation of the electrical angle of 360° of the first rotor (inner magnet cylinder 23). As described above, since the least common multiple LCM of the number of poles of the first rotor (inner magnet cylinder 23), which is the number of the first permanent magnets 25, and the number of pole pieces 29 is 24, the magnetic gear torque vibrates 6K (=(24K / (8 / 2)) times at an electrical angle of 360°. As a result, it contains many components that vibrate six times with K = 1.

[0051] As shown in Fig. 16, it can be seen that the rotating electrical machine torque is dominated by the sixth-order torque pulsation component that vibrates six times while the rotor 12 rotates through an electrical angle of 360°. It is generally known that when a current is applied to the rotating electrical machine 10, the component of torque pulsation that vibrates (6×N1) times while rotating through 360° in electrical angle increases, where N1 is a natural number. As shown in the figure, the magnitude Tγ of the torque pulsation of the combined torque waveform, which is the difference (P-P) between the maximum value and the minimum value of the waveform, is significantly smaller compared to the torque waveform of the rotating electrical machine 10 and the torque waveform of the magnetic gear 20, and the torque pulsation is significantly reduced.

[0052] Also in this second embodiment, similar to the first embodiment above, if the main order of the torque pulsation of the rotating electrical machine 10 and the main order of the torque pulsation of the magnetic gear 20 match, by adjusting the phase relationship, a reduction effect of torque pulsation can be obtained for the combined torque. That is, if the number of poles of the rotor 12 of the rotating electrical machine 10 × (3×N1) satisfies the condition of matching the least common multiple LCM of the number of poles of the first rotor (inner magnet cylinder 23) connected to the rotating shaft 11 of the rotating electrical machine 10 and the number of pole pieces 29, when a current is applied to the rotating electrical machine 10, a reduction effect of torque pulsation can be obtained. In this case, the above least common multiple LCM (=24) is three times the number of poles of the rotor 12 of the rotating electrical machine 10 (=8), satisfies the above condition with N1 = 1, and a reduction effect of torque pulsation can be obtained.

[0053] Also, the phase of the torque pulsation of the rotating electrical machine 10 during current application varies depending on the amplitude and phase state of the current and the cross-sectional shape of the rotating electrical machine 10. Therefore, for the phase adjustment method, in the state of the amplitude and phase of the desired current to which low vibration is to be imparted, an arrangement is made such that the torque pulsation is canceled out. For example, in the drive motor of an automobile, since there are many operating states in the low to medium torque range, a phase relationship is set such that the torque pulsation is canceled out under the conditions of the amplitude and phase of the current in these torque ranges.

[0054] Regarding the phase adjustment at this time, similar to the first embodiment above, when the circumferential magnetic pole center of the first rotor (inner magnet cylinder 23) coincides with the circumferential center position of the pole piece 29, the phase (deviation phase θ) between the circumferential magnetic pole center of the rotor 12 and the circumferential center position of the teeth 16 can be adjusted. By adjusting the phases so as to reduce the torque pulsation of the rotating electrical machine 10 and the torque pulsation of the magnetic gear 20 with respect to each other, the torque pulsation can be effectively reduced, and the speed vibration caused by the torque pulsation can be suppressed.

[0055] The condition that the least common multiple LCM of the number N of the pole pieces 29 of the magnetic gear 20 and the number of poles of the first rotor (inner magnet cylinder 23) shown in the first embodiment above coincides with the least common multiple M of the number of poles of the rotor 12 of the rotating electrical machine 10 and the number of teeth 16 is defined as the first condition. And the condition that the least common multiple LCM of the number N of the pole pieces 29 of the magnetic gear 20 and the number of poles of the first rotor (inner magnet cylinder 23) shown in this embodiment coincides with the number of poles of the rotor 12 of the rotating electrical machine 10 × (3 × N1) is defined as the second condition. By setting the first condition and the second condition in this way, if at least one of the first condition and the second condition is satisfied, the effect of reducing the torque pulsation can be obtained.

[0056] In the magnetic gear device 100 used in this embodiment, the least common multiple LCM (= 24) of the number N of the pole pieces 29 of the magnetic gear 20 and the number of poles of the first rotor (inner magnet cylinder 23) coincides with the least common multiple M (= 24) of the number of poles of the rotor 12 of the rotating electrical machine 10 and the number of teeth 16, and also coincides with three times the number of poles of the rotor 12. Therefore, both the first condition and the second condition are satisfied. For this reason, the magnetic gear device 100 can obtain the effect of reducing the torque pulsation both when no current is applied and when current is applied.

[0057] Embodiment 3. FIG. 17 is a longitudinal sectional view showing the configuration of the magnetic gear device according to Embodiment 3. As shown in FIG. 17, the magnetic gear device 100A is composed of a drive unit including a rotating electrical machine 10 and a magnetic gear 20A. The rotary electric machine 10 is the same as that in the first embodiment. The magnetic gear 20A includes an inner magnet cylinder 23 that constitutes a low-pole mechanism with a small number of magnetic poles, an outer magnet cylinder 26A that constitutes a multi-pole mechanism with a large number of magnetic poles, and a magnetic body cylinder 30A that is disposed between the inner magnet cylinder 23 and the outer magnet cylinder 26A with a magnetic gap 31 therebetween on both sides. The cross-section has the same configuration as that in FIG. 3, but the combination of the number of the first permanent magnets 25 in the inner magnet cylinder 23, the number of the second permanent magnets 28 in the outer magnet cylinder 26A, and the number of the pole pieces 29 in the magnetic body cylinder 30A is different.

[0058] The magnetic gear 20A arranges the inner magnet cylinder 23, the outer magnet cylinder 26A, and the magnetic body cylinder 30A concentrically. Among these three, one is a first rotor connected to the input section 21, another is a second rotor connected to the output section 22, and the remaining one is used as a stator. In this embodiment, the inner magnet cylinder 23 is used as the first rotor, the magnetic body cylinder 30A is used as the second rotor, and the outer magnet cylinder 26A is used as the stator. Other configurations are the same as those in the first embodiment.

[0059] That is, in this embodiment, the rotor 12 of the rotary electric machine 10 and the first rotor (inner magnet cylinder 23) of the magnetic gear 20A are provided coaxially, and the first rotor (inner magnet cylinder 23) of the magnetic gear 20A rotates together with the rotation shaft 11 of the rotary electric machine 10. Thereby, a magnetomotive force is applied to the pole pieces 29 of the second rotor (magnetic body cylinder 30A) disposed between the stator (outer magnet cylinder 26A) and the first rotor (inner magnet cylinder 23). Then, the second rotor (magnetic body cylinder 30A) rotates in the same direction as the first rotor (inner magnet cylinder 23). In this way, the magnetic gear device 100A decelerates and increases torque or accelerates and decreases torque the driving force generated by the rotary electric machine 10, and outputs it from the output section 22 corresponding to the output shaft of the magnetic gear 20A.

[0060] The combinations of the number of the first permanent magnets 25 in the inner magnet cylinder 23 of the magnetic gear 20A, the number of the second permanent magnets 28 in the outer magnet cylinder 26A, and the number N of the pole pieces 29 in the magnetic cylinder 30A are shown below. Let X and Y (>X) be natural numbers. The number of the first permanent magnets 25 in the inner magnet cylinder 23 is 2X, the number of the second permanent magnets 28 in the outer magnet cylinder 26A is 2Y, and the number N of the pole pieces 29 in the magnetic cylinder 30A is (X + Y).

[0061] While the first rotor (inner magnet cylinder 23) rotates 360° in electrical angle, that is, (360 / X + 360 / Y)° in mechanical angle, with respect to the second rotor (magnetic cylinder 30), the magnetic gear torque vibrates (LCM(2X, (X + Y)) / X) times, which is the number of times obtained by dividing the least common multiple LCM of the number N of the pole pieces 29 and the number of poles of the first rotor (inner magnet cylinder 23) by X. That is, the number of times the magnetic gear torque vibrates while the first rotor (inner magnet cylinder 23) rotates 360° in mechanical angle is (LCM(2X, (X + Y)) / X)×(360 / (360 / X + 360 / Y)) = LCM(2X, (X + Y))×(Y / (X + Y)).

[0062] Therefore, the combinations of the number of the first permanent magnets 25 in the inner magnet cylinder 23, the number of the second permanent magnets 28 in the outer magnet cylinder 26A, and the number N of the pole pieces 29 in the magnetic cylinder 30A are determined so that the least common multiple M of the number of poles of the rotor 12 of the rotating electrical machine 10 and the number of teeth 16 coincides with LCM(2X, (X + Y))×(Y / (X + Y)), thereby constituting the magnetic gear 20A. That is, the ((number of poles of the stator (outer magnet cylinder 26A)) / N) times of the least common multiple LCM of the number N of the pole pieces 29 and the number of poles of the first rotor (inner magnet cylinder 23) is set as the first numerical value, and the first condition that the first numerical value coincides with the least common multiple M of the number of poles of the rotor 12 of the rotating electrical machine 10 and the number of teeth 16 is satisfied.

[0063] Thus, when no current is applied to the rotating electrical machine 10, if the orders of the main torque pulsations of the rotating electrical machine 10 and the main torque pulsations of the magnetic gear 20A match, they can cancel each other out and be reduced by adjusting the phase relationship, and the torque pulsation of the combined torque is reduced. Also in this case, similar to the first embodiment, the phase (deviation phase θ) between the circumferential magnetic pole center of the rotor 12 and the circumferential center position of the teeth 16 when the circumferential magnetic pole center of the first rotor (inner magnet cylinder 23) coincides with the circumferential magnetic pole center of the stator (outer magnet cylinder 26A) is adjusted. Then, by adjusting the phases of the torque pulsation of the rotating electrical machine 10 and the torque pulsation of the magnetic gear 20 to reduce each other, the torque pulsation can be effectively reduced and the speed vibration caused by the torque pulsation can be suppressed.

[0064] In this way, the magnetic gear device 100A can reduce the output torque pulsation and suppress the speed vibration on the output side. Also, similar to the first embodiment, no special processing is required for the first and second permanent magnets 25 and 28 used in the magnetic gear 20A, and the magnetic gear device 100A can be manufactured easily and inexpensively.

[0065] Note that the configuration of the magnetic gear device 100A may be set so as to satisfy the second condition that the first numerical value which is ((the number of poles of the stator (outer magnet cylinder 26A)) / N) times the least common multiple LCM of the number N of the pole pieces 29 and the number of poles of the first rotor (inner magnet cylinder 23) coincides with the number of poles of the rotor 12 of the rotating electrical machine 10×(3×N1). In that case, as shown in the second embodiment, when current is applied to the rotating electrical machine 10, the effect of reducing the torque pulsation can be obtained. That is, if at least one of the first condition and the second condition is satisfied, the effect of reducing the torque pulsation can be obtained by adjusting the phase relationship. Also, when both the first condition and the second condition are satisfied, the magnetic gear device 100A can obtain the effect of reducing the torque pulsation both when no current is applied and when current is applied.

[0066] Also, in this embodiment, a magnetic cylinder 30A having a pole piece 29 rotates as a first rotor, and the gear ratio can be improved compared to the first embodiment. Further, since the outer magnet cylinder 26A on the outermost periphery of the magnetic gear 20A serves as a stator, the structure can be simplified and the manufacturing cost can be reduced.

[0067] Further, it is desirable that the magnetic gear 20A satisfies at least one of the conditions that the number of poles of the first rotor (inner magnet cylinder 23) connected to the output shaft of the rotating electrical machine 10 is equal to or more than the number of poles of the rotor 12 of the rotating electrical machine 10, and that the number of pole pieces 29 of the second rotor (magnetic cylinder 30A) is equal to or more than the number of teeth 16 of the rotating electrical machine 10. Thereby, the magnetic gear 20A can be surely selected so that the main order of the torque ripple generated by the magnetic gear 20A is equal to or higher than the order of the torque ripple generated by the rotating electrical machine 10, and the torque ripple of the combined torque output from the magnetic gear device 100A can be suppressed.

[0068] In the above embodiment, an example in which the stator (outer magnet cylinder 26A) is fixed is shown, but the stator (outer magnet cylinder 26A) may be configured to be freely rotatable and arbitrarily phase-adjustable, and the same effect can be obtained.

[0069] In each of the above embodiments, an example in which the rotating shaft 11 of the rotating electrical machine 10 and the rotating shafts (input portions 21) of the magnetic gears 20 and 20A are arranged coaxially is shown, but the present invention is not limited to this. The same effect can be obtained as long as the rotating shaft 11 of the rotating electrical machine 10 and the input portion 21 of the magnetic gears 20 and 20A are connected.

[0070] Embodiment 4. In this Embodiment 4, a configuration in which the rotor 12 of the rotating electrical machine 10 in the magnetic gear device 100A of Embodiment 3 and the first rotor (inner magnet cylinder 23) of the magnetic gear 20 are integrally formed is shown. FIG. 18 is a longitudinal sectional view showing the configuration of the magnetic gear device according to Embodiment 4. As shown in Fig. 18, the magnetic gear device 100B is composed of a drive unit including a rotary electric machine 10A and a magnetic gear 20B. In this case, the rotor 12A of the rotary electric machine 10A is integrally formed with the first rotor (inner magnet cylinder 23A) of the magnetic gear 20B. Other configurations are the same as those in the third embodiment above.

[0071] In this embodiment, since the rotor core material is shared by the magnetic gear 20B and the rotary electric machine 10A, and the number of structural members can be further reduced, the manufacturing cost can be further reduced. Also in this case, if at least one of the first condition and the second condition shown in the third embodiment above is satisfied, similar to the third embodiment, torque pulsation can be reduced by adjusting the phase relationship, and speed vibration on the output side can be suppressed. The first condition is that the ((number of poles of the stator (outer magnet cylinder 26A)) / N) times the least common multiple LCM of the number N of pole pieces 29 and the number of poles of the first rotor (inner magnet cylinder 23A) is taken as the first numerical value, and the first numerical value coincides with the least common multiple M of the number of poles of the rotor 12 of the rotary electric machine 10 and the number of teeth 16. The second condition is that the first numerical value coincides with the number of poles of the rotor 12 of the rotary electric machine 10 × (3 × N1).

[0072] In the fourth embodiment above, a configuration in which the rotary electric machine 10A and the magnetic gear 20B are housed in the same frame 18A is shown, but they may be housed in separate frames.

[0073] Also, in the first to fourth embodiments above, examples of the magnetic gears 20, 20A, and 20B as reduction gears for deceleration and torque increase are shown. However, if the outer magnet cylinder 26, which is a multi-pole mechanism of the magnetic gears 20, 20A, and 20B, is used as the first rotor and connected to the rotary shafts 11 of the rotary electric machines 10 and 10A, a configuration of a speed increasing gear for speed increase and torque reduction can be realized. Also in that case, the same effects as those in the above embodiments can be obtained.

[0074] Embodiment 5. Fig. 19 is a longitudinal sectional view showing the configuration of the magnetic gear device according to Embodiment 5. As shown in Fig. 19, the magnetic gear device 100C is composed of a drive unit including a rotating electrical machine 10 and a magnetic gear 20C. In this embodiment, the magnetic gear 20C has an inner magnet cylinder 23B, an outer magnet cylinder 26A, and a magnetic body cylinder 30B arranged concentrically. The magnetic body cylinder 30B is used as the first rotor, either the inner magnet cylinder 23B or the outer magnet cylinder 26A is used as the second rotor, and the other is used as the stator. In this case, the case where the inner magnet cylinder 23B is used as the second rotor and the outer magnet cylinder 26A is used as the stator is illustrated. Other configurations are the same as those in the first embodiment.

[0075] In this case, the ((number of poles of the stator (outer magnet cylinder 26A or inner magnet cylinder 23B)) / N) times the least common multiple of the number N of pole pieces 29 and the number of poles of the second rotor (inner magnet cylinder 23B or outer magnet cylinder 26A) is set as the first value. And the first condition that this first value matches the least common multiple M of the number of poles of the rotor 12 of the rotating electrical machine 10 and the number of teeth 16 is satisfied. Thereby, when no current is applied to the rotating electrical machine 10, if the order of the main torque pulsation of the rotating electrical machine 10 and the order of the main torque pulsation of the magnetic gear 20C match, they can be offset and reduced by adjusting the phase relationship, and the torque pulsation of the combined torque is reduced.

[0076] Also in this case, similar to the first embodiment, the circumferential magnetic pole center of the first rotor (magnetic body cylinder 30B), that is, the circumferential center position of the pole piece 29, is adjusted for the phase (deviation phase θ) between the circumferential magnetic pole center of the rotor 12 and the circumferential center position of the teeth 16 when it coincides with the circumferential magnetic pole center of the stator (outer magnet cylinder 26A or inner magnet cylinder 23B). And by adjusting the phase so that the torque pulsation of the rotating electrical machine 10 and the torque pulsation of the magnetic gear 20C reduce each other, the torque pulsation can be effectively reduced and the speed vibration caused by the torque pulsation can be suppressed.

[0077] Further, the first numerical value may be set so as to satisfy a second condition that matches the number of poles of the rotor 12 of the rotating electrical machine 10 × (3 × N1). In that case, as shown in the second embodiment, when current is applied to the rotating electrical machine 10, an effect of reducing torque ripple can be obtained. That is, if at least one of the first condition and the second condition is satisfied, an effect of reducing torque ripple can be obtained by adjusting the phase relationship.

[0078] In each of the above embodiments, the permanent magnets constituting the magnetic poles of the rotating electrical machine 10 and the magnetic gears 20, 20A, 20B, 20C are not limited to one. The same effect can be obtained even when the permanent magnet is divided in the magnetization direction, the direction orthogonal to the magnetization, the axial direction, and other directions.

[0079] Further, although an example in which the rotating electrical machine 10 and the magnetic gears 20, 20A, 20B, 20C are of a radial type having a magnetic gap in a direction orthogonal to the rotation axis is shown, the same effect can be obtained even in an axial type having a magnetic gap in a direction parallel to the rotation axis.

[0080] Further, although an example in which the rotating electrical machine 10 has 8 poles and 12 slots is shown, if the relationship between the number of poles of the rotors of the magnetic gears 20, 20A, 20B, 20C and the number of pole pieces 29 shown in each of the above embodiments satisfies the above-described conditions, the same effect can be obtained even with other pole-slot number configurations.

[0081] Further, in the first embodiment, an example in which the fewer-pole mechanism (inner magnet cylinder 23) of the magnetic gear 20 has 8 poles, the multi-pole mechanism (outer magnet cylinder 26) has 40 poles, and the number of pole pieces 29 is 24 is shown. However, for example, the following combinations may also be used. When the number of poles Ns of the fewer-pole mechanism is smaller than the number of poles Nm of the multi-pole mechanism, and the number of pole pieces 29 is set as Np, if l and m are both natural numbers, the relationship (2l - 1)Np = Nm ± (2m - 1)Ns is satisfied. And for the combinations that satisfy the torque ripple reduction conditions shown in each of the above embodiments, the same effect can be obtained.

[0082] Also, in each of the above embodiments, the shapes of the teeth 16, pole pieces 29, permanent magnets 13, 25, and 28 of the rotating electrical machine 10 and the magnetic gears 20, 20A, 20B, and 20C are shown in the simplest shapes, but the following may also be used. For example, the shapes of the teeth 16 and the pole pieces 29 may be tapered radially toward the magnetic gap or may have a shape that tapers at the bottom. Also, bonded magnets may be used for the permanent magnets 13, 25, and 28, or two or more permanent magnets per pole may be used and embedded in a V shape. In any case, if the pole arrangement related to the magnetic gap has the same relationship as in each of the above embodiments, the same effects can be obtained.

[0083] This application describes various exemplary embodiments and examples, but the various features, aspects, and functions described in one or more embodiments are not limited to the application of a specific embodiment, but are applicable to the embodiments alone or in various combinations. Therefore, countless variations not illustrated are envisioned within the scope of the technology disclosed in this application. For example, it includes cases where at least one component is deformed, added, or omitted, and further, cases where at least one component is extracted and combined with the components of other embodiments.

Description of Reference Numerals

[0084] 10, 10A Rotating electrical machine, 11 Rotating shaft, 12, 12A Rotor, 13 Permanent magnet, 15 Stator, 16 Teeth, 20, 20A, 20B, 20C Magnetic gear, 21 Input part, 22 Output part, 23, 23A, 23B Inner magnet cylinder, 25 First permanent magnet, 26, 26A Outer magnet cylinder, 28 Second permanent magnet, 29 Pole piece, 30, 30A, 30B Magnetic body cylinder, 31 Magnetic gap, 100, 100A, 100B, 100C Magnetic gear device, θ, φ Phase shift.

Claims

1. An inner magnet cylinder in which a plurality of first permanent magnets are arranged on the outer circumference to form a multi-pole mechanism, an outer magnet cylinder in which a plurality of second permanent magnets are arranged on the inner circumference to form a multi-pole mechanism, and the inner magnet cylinder and the outer magnet cylinder are arranged between each other through a magnetic gap, and a magnetic cylinder having N pole pieces made of a soft magnetic material arranged at equal intervals in the circumferential direction, and among the inner magnet cylinder, the outer magnet cylinder, and the magnetic cylinder, a first rotor connected to an input part, a second rotor connected to an output part, and the remaining one used as a stator, a magnetic gear; A rotating electrical machine including a rotor having M1 permanent magnets and a stator having M2 teeth; In the magnetic gear, the input part is connected to the rotating shaft of the rotating electrical machine, and the input rotational force is transmitted to the output part; A first numerical value based on the least common multiple of the number N of the pole pieces and the number of poles of one of the first and second rotors coincides with the least common multiple M of M1 and M2, and a second condition that coincides with a number obtained by multiplying M1 by a multiple of 3, satisfying at least one of them; A magnetic gear device.

2. By adjusting the phase between the circumferential magnetic pole center of the rotor of the rotating electrical machine and the circumferential center position of the teeth when the circumferential magnetic pole center of the first rotor coincides with the circumferential magnetic pole center of the stator of the magnetic gear, the torque ripple of the rotating electrical machine and the torque ripple of the magnetic gear are reduced with respect to each other. The magnetic gear device according to Claim 1.

3. The magnetic cylinder is used as the stator of the magnetic gear; The least common multiple of the number N of the pole pieces and the number of poles of the first rotor is the first numerical value; The magnetic gear device according to Claim 1 or Claim 2.

4. When the circumferential magnetic pole center of the first rotor coincides with the circumferential center position of the pole piece that is the pole of the stator, the circumferential magnetic pole center of the rotor of the rotating electrical machine is shifted in phase by a set angle from the circumferential center position of the teeth, so that the torque ripple of the rotating electrical machine and the torque ripple of the magnetic gear are reduced with respect to each other. The magnetic gear device according to Claim 3.

5. The set angle is larger than (360 / M / 6) degrees and smaller than ((360 / M / 6) × 5) degrees; The magnetic gear device according to Claim 4.

6. The magnetic cylinder is used as the second rotor of the magnetic gear; The first numerical value is the least common multiple of the number N of the pole pieces and the number of poles of the first rotor multiplied by ((the number of poles of the stator) / N). The magnetic gear device according to claim 1 or claim 2.

7. The number of poles of the first rotor ≧ M1. The magnetic gear device according to claim 1 or claim 2.

8. The number of poles of the first rotor = M1. The magnetic gear device according to claim 7.

9. The magnetic cylinder is used as the first rotor of the magnetic gear. The first numerical value is the least common multiple of the number N of the pole pieces and the number of poles of the second rotor multiplied by ((the number of poles of the stator) / N). The magnetic gear device according to claim 1 or claim 2.

10. N ≧ M2. The magnetic gear device according to claim 9.

11. The input part of the magnetic gear is integrally formed with the rotating shaft of the rotating electrical machine. The magnetic gear device according to claim 1 or claim 2.

Images