Magnetic gear unit

Abstract

A magnetic drive device (100) comprises: a magnetic drive (20) having an inner magnet tube (23) which is a less-pole mechanism, an outer magnet tube (26) which is a multi-pole mechanism, and pole pieces (29) arranged circumferentially at equal intervals between them and positioned between the inner magnet tube (23) and the outer magnet tube (26), such that one of the inner magnet tube (23), the outer magnet tube (26) and one set of pole pieces (29) is used as a first rotor connected to an input region (21), another is used as a second rotor connected to an output region (22), and the remaining one is used as a stator, and a rotating electric machine (10) having a rotor (12) having permanent magnets (13) and a stator (15) having teeth (16).At least one of the following conditions is satisfied: a first value based on the least common multiple of the number of pole pieces (29) and the number of poles of one of the first and second rotors corresponds to the least common multiple of the number of poles of the rotor (12) and the number of teeth (16); and a second condition that the first value corresponds to a value obtained by multiplying the number of poles of the rotor (12) by a multiple of 3.

Description

Technical area

[0001] The present invention relates to a magnetic gear device. State of the art

[0002] Recently, a magnetic gear has been used in combination with a rotating electric machine to obtain a desired output power and efficiency characteristics from the rotating electric machine.

[0003] In a conventional magnetic gear forming a magnetic gear device, a cylindrical inner magnetic tube having a plurality of magnets arranged side by side on an outer circumference, a cylindrical outer magnetic tube having a plurality of magnets arranged side by side on an inner circumference, and a cylindrical magnetic material tube having a plurality of magnetic elements arranged side by side with equal intervals therebetween in the circumferential direction are coaxially held, the magnetic material tube is interposed between the inner magnetic tube and the outer magnetic tube, any two of the inner magnetic tube, the outer magnetic tube, and the magnetic material tube are used as rotors, and the remaining one is used as a stator, so that rotational torque is transmitted.

[0004] Each magnetic element has a block shape parallel to the axial longitudinal direction of the magnetic material tube, and the magnets of the inner magnetic tube and the outer magnetic tube have positional shifts toward the same sides in the circumferential direction between one end and the other end in the axial longitudinal direction, so that they are arranged in an oblique or twisted manner.

[0005] While ensuring a high torque density, the cogging torque is effectively reduced so that the kinetic energy can be transmitted stably with reduced torque fluctuation. BibliographyPatent document

[0006] Patent Document 1: Japanese Patent JP 6 213 573 B2 Summary of the inventionProblem to be solved by the invention

[0007] In the conventional magnetic gear train described in Patent Document 1, permanent magnets must be skewed or twisted sequentially in the axial direction, making manufacturing difficult. Furthermore, while torque pulsation can be reduced with a magnetic gear train alone, speed fluctuation due to torque pulsation of a rotating electric machine also occurs on the output side of the magnetic gear train.

[0008] The present invention was conceived to solve the above problem, and the object of the present invention is to provide a magnetic gear device that can reduce speed fluctuation on the output side by reducing the torque pulsation output from a combination of a magnetic gear and a rotating electric machine. Another object of the present invention is to manufacture the magnetic gear device easily and at a low cost. Ways to solve the problem

[0009] A magnetic gear device according to the present invention comprises: a magnetic gear comprising an inner magnetic tube having a plurality of first permanent magnets arranged on an outer circumference to form a few-pole mechanism, an outer magnetic tube having a plurality of second permanent magnets arranged on an inner circumference to form a multi-pole mechanism, and a magnetic material tube arranged between the inner magnetic tube and the outer magnetic tube, with magnetic gaps interposed therebetween from both the inner magnetic tube and the outer magnetic tube. The magnetic material tube has N pole pieces formed of a soft magnetic material and arranged at equal intervals therebetween in the circumferential direction, so that one of the inner magnetic tube, the outer magnetic tube, and the magnetic material tube is used as a first rotor.which is connected to an input section, another is used as a second rotor connected to an output section, and the remaining one is used as a stator; and a rotating electrical machine having a rotor with M1 permanent magnets and a stator with M2 teeth.

[0010] The magnetic gear is configured such that the input section is connected to a rotating shaft of the rotating electric machine, and an input rotational force is transmitted to the output section. At least one of a first condition that a first value based on the lowest common multiple of the number N of pole pieces and the number of poles of one of the first and second rotors coincides with the lowest common multiple M of M1 and M2, and a second condition that the first value coincides with a value obtained by multiplying M1 by a multiple of 3, is satisfied. Effect of the invention

[0011] With the magnetic gear device according to the present invention, torque pulsation output from a combination of magnetic gear and rotating electric machine can be reduced, thus suppressing speed fluctuation on the output side. Furthermore, the magnetic gear device can be manufactured easily and at low cost. Short description of the drawings Fig. 1 is a vertical sectional view showing the configuration of a magnetic gear device according to Embodiment 1. Fig. 2 is a transverse sectional view showing the configuration of a rotating electric machine in the magnetic gear device according to Embodiment 1. Fig. 3 is a transverse sectional view showing the configuration of a magnetic gear in the magnetic gear device according to Embodiment 1. Fig. 4 is a partially transverse sectional view showing the positional relationship of parts of the magnetic gear according to Embodiment 1. Fig. 5 is a waveform diagram showing the magnetic gear torque of the magnetic gear device according to Embodiment 1. Fig. 6 is a partially transverse sectional view showing the positional relationship of parts of the rotating electric machine according to Embodiment 1. Fig. 7 is a waveform diagram showing the torque of the rotating electric machine in the magnetic gear device according to Embodiment 1 in a case where no current is applied. Fig. 8 is a waveform diagram showing the rotating electric machine torque, the magnetic gear torque, and a combined torque in the magnetic gear device according to Embodiment 1 in a case where no current is applied. Fig. 9 is a waveform diagram showing a change in torque pulsation of the combined torque with respect to a phase shift of a rotor of the rotating electric machine in the magnetic gear device according to Embodiment 1. Fig. 10 shows amplitudes in a frequency analysis result of the magnetic gear torque in the magnetic gear device according to Embodiment 1. Fig. 11 shows amplitudes in a frequency analysis result of the torque of the rotating electric machine in the magnetic gear device according to Embodiment 1. Fig. 12 is a waveform diagram showing a sixth-order component of torque, in a generalized manner, in the magnetic gear device according to Embodiment 1. Fig. 13 is a waveform diagram showing a twelfth-order component of torque, in a generalized manner, in the magnetic gear device according to Embodiment 1. Fig. 14 is a waveform diagram showing torque pulsations of a sixth-order component and a twelfth-order component of the combined torque, in a generalized manner, in the magnetic gear device according to Embodiment 1. Fig. 15 is a vertical sectional view showing the configuration of a magnetic gear device according to another example of Embodiment 1. Fig. 16 is a waveform diagram showing the rotating electric machine torque, the magnetic gear torque, and the combined torque in a magnetic gear device according to Embodiment 2 when power is applied. Fig. 17 is a vertical sectional view showing the configuration of a magnetic gear device according to Embodiment 3. Fig. 18 is a vertical sectional view showing the configuration of a magnetic gear device according to Embodiment 4. Fig. 19 is a vertical sectional view showing the configuration of a magnetic gear device according to Embodiment 5. Description of embodimentsEmbodiment 1

[0012] Fig. 1 is a vertical sectional view showing the configuration of a magnetic gear device according to Embodiment 1. As shown in Fig. 1, a magnetic gear device 100 is designed as a drive unit which has a rotating electrical machine 10 and a magnetic gear 20.

[0013] Fig. Fig. 2 is a transverse sectional view showing the configuration of the rotating electric machine 10 in the magnetic gear device 100, and it shows a cross section taken along the line AA in Fig. 1.

[0014] Fig. Fig. 3 is a transverse sectional view showing the configuration of the magnetic gear 20 in the magnetic gear device 100, and it shows a cross section taken along the line BB in Fig. 1.

[0015] As shown in the drawings, a shaft, which is the rotating shaft 11 of the rotating electric machine 10, is connected to an input portion 21 of the magnetic gear 20, and the magnetic gear 20 transmits a rotational force supplied to the input portion 21 to an output portion 22. In this case, the input portion 21 of the magnetic gear 20 is formed integrally with the rotating shaft 11 of the rotating electric machine 10. The rotating electric machine 10 includes a rotor 12 and a stator 15 arranged around the outer periphery of the rotor 12 with a magnetic gap interposed therebetween.

[0016] The rotor 12 is configured such that a plurality (M1) of, in this case, eight, permanent magnets 13, which serve as magnetic poles, are arranged side by side in the circumferential direction on the outer peripheral surface of a rotor core 14. The permanent magnets 13 are magnetized in the radial direction and are arranged such that the polarities of adjacent permanent magnets 13 are opposite to each other.

[0017] The stator 15 has a plurality (M2) of, in this case, twelve, teeth 16 projecting toward the magnetic gap, and a coil 17 is wound around each tooth 16. Consequently, the rotating electrical machine 10 has a concentrated winding structure, as an example with eight poles and twelve slots, in which eight permanent magnets 13 and twelve teeth 16 are arranged. For simplification, the coils 17 are in Fig. 2 not shown.

[0018] The magnetic gear 20 includes an inner magnetic tube 23 forming a few-pole mechanism with a smaller number of magnetic poles, an outer magnetic tube 26 forming a multi-pole mechanism with a larger number of magnetic poles, and a magnetic material tube 30 disposed between the inner magnetic tube 23 and the outer magnetic tube 26, with magnetic gaps 31 interposed therebetween from both the inner magnetic tube 23 and the outer magnetic tube 26.

[0019] The inner magnet tube 23 is configured such that a plurality of—in this case, eight—first permanent magnets 25, which serve as magnetic poles, are arranged side by side in the circumferential direction on an outer peripheral surface of a cylindrical support body 24. The first permanent magnets 25 are magnetized in the radial direction and are arranged such that the polarities of adjacent first permanent magnets 25 are opposite to each other.

[0020] The outer magnet tube 26 is configured such that a plurality of—in this case, forty—second permanent magnets 28, which serve as magnetic poles, are arranged side by side in the circumferential direction on an inner peripheral surface of a cylindrical support body 27. The second permanent magnets 28 are magnetized in the radial direction and are arranged such that the polarities of adjacent second permanent magnets 28 are opposite to each other.

[0021] The magnetic material tube 30, which is arranged between the inner magnetic tube 23 and the outer magnetic tube 26, is formed such that N—in this case twenty-four—pole pieces 29 made of soft magnetic materials are arranged at equal intervals therebetween in the circumferential direction.

[0022] Parts where a driving force and a transmission process occur (hatched parts in Fig. 1), namely in the rotating electrical machine 10 and the magnetic gear 20, are formed of a magnetic material. These parts are protected by frames (a rotating electrical machine frame 18 and a magnetic gear frame 32) and bearing shells (a rotating electrical machine bearing shell 19 and a magnetic gear bearing shell 33), which are formed by structural elements made of iron, a non-magnetic material, or the like.

[0023] In the magnetic gear 20, the inner magnetic tube 23, the outer magnetic tube 26 and the magnetic material tube 30 are arranged concentrically, one of the three tubes is used as a first rotor connected to the input section 21, another is used as a second rotor connected to the output section 22, and the remaining one is used as a stator.

[0024] Not only the first and second permanent magnets 25 and 28 of the magnetic gear 20, but also the N pole pieces 29 made of a soft magnetic material are referred to as magnetic poles of the rotor or the stator.

[0025] In the present embodiment, the inner magnetic tube 23 is used as the first rotor, the outer magnetic tube 26 is used as the second rotor, and the magnetic material tube 30 is used as the stator. The rotor 12 of the rotating electric machine 10 and the first rotor (inner magnetic tube 23) and the second rotor (outer magnetic tube 26) of the magnetic gear 20 are supported by a plurality of bearings 35.

[0026] That is, in the present embodiment, the rotor 12 of the rotating electric machine 10 and the first rotor (inner magnetic tube 23) of the magnetic gear 20 are coaxially arranged, and the first rotor (inner magnetic tube 23) of the magnetic gear 20 rotates together with the rotating shaft 11 of the rotating electric machine 10.

[0027] The first permanent magnets 25 of the first rotor (inner magnet tube 23) rotate while sequentially passing the pole pieces 29 of the magnetic material tube 30, which serves as the stator, so that a magnetic flux is generated at the second permanent magnet 28 of the second rotor (outer magnet tube 26). The second rotor (outer magnet tube 26) then rotates in a direction opposite to the first rotor (inner magnet tube 23).

[0028] In the magnetic gear device 100 configured as described above, the driving force generated by the rotating electric machine 10 is subjected to a speed reduction and a torque increase, or a speed increase and a torque decrease, by the magnetic gear 20, and the resulting power is output from the output section 22 corresponding to an output shaft of the magnetic gear 20. In the present embodiment, a configuration for performing a speed reduction and a torque increase is shown.

[0029] The number of first permanent magnets 25 of the first rotor (inner magnetic tube 23) is eight, the number of second permanent magnets 28 of the second rotor (outer magnetic tube 26) is forty, and the number of pole pieces 29 is twenty-four. Therefore, the gear ratio of the magnetic gear 20 is (40 / 2) / (8 / 2) = 5. That is, through the magnetic gear 20, the rotational force supplied to the input section 21 undergoes a 1 / 5-fold speed reduction and a 5-fold torque increase, and the resulting power is output to the output section 22.

[0030] Fig. 4 is a partially transverse sectional view showing the positional relationship of parts of the magnetic gear 20. In Fig. 4 shows one of the first permanent magnets 25 of the first rotor (inner magnet tube 23) together with the pole pieces 29 of the magnetic material tube 30. That is, a circumferential direction range of 45° (= (360° / 8)) at the mechanically defined angle (hereinafter referred to as the mechanical angle) is shown.

[0031] Fig. 5 is a waveform diagram showing the magnetic gear torque of the magnetic gear device 100. In Fig. 5 shows a torque waveform of the first rotor (inner magnet tube 23) when the first rotor (inner magnet tube 23) is rotated by 360° in the electrically defined angle (hereinafter referred to as electrical angle), ie, 90° (= (360° / (8 / 2))) in the mechanical angle.

[0032] As in Fig. As shown in Figure 5, torque pulsation occurs six times in the magnetic gear torque while the first rotor (inner magnet tube 23) rotates through an electrical angle of 360°. The torque pulsation occurs when the pole pieces 29 made of a magnetic material are similarly arranged at regular intervals at positions opposite to the first permanent magnets 25, which are arranged at regular intervals. This is also referred to as cogging torque.

[0033] The number of times of torque pulsation is determined by the relationship between the numbers of the first permanent magnets 25 and the pole pieces 29. As a general theory, it is known that, in a case where the first rotor (inner magnet tube 23) with the first permanent magnets 25 rotates 360° in mechanical angle, the number of times of torque pulsation is a multiple of the lowest common multiple LCM of the number of first permanent magnets 25 and the number of pole pieces 29.

[0034] In this case, LCM(8, 24) has a value of 24, and the magnetic gear torque contains a component that rotates 24K (K is a natural number) times in a mechanical angular range of 360°. Consequently, the magnetic gear torque oscillates 6K (= (24K / (8 / 2)) times in an electrical angular range of 360°, and a component that oscillates six times at K = 1 is included in a large value, which is consistent with the result obtained in Fig. 5 is shown.

[0035] In Fig. 5, the phase of the torque waveform is shown such that the angle when there is a cross section in which a circumferential magnetic pole center position of the first rotor (inner magnet tube 23) rotating in the direction of arrow 40 coincides with a circumferential center position of the pole piece 29 as shown with a center line 41 in Fig. 4, is defined as an initial angle of 0°.

[0036] Fig. 6 is a partially transverse sectional view showing a positional relationship of parts of the rotating electrical machine 10. In Fig. 6, in a circumferential direction region (mechanical angle range of 45°) of one of the permanent magnets 13 of the rotor 12 of the rotating electrical machine 10, the rotor core 14, the permanent magnet 13 and one of the teeth 16 of the stator 15 are shown.

[0037] In Fig. 6, the state in which the circumferential direction magnetic pole center position (center line 43) of the rotor 12 rotating in the direction of the arrow 42 coincides with the circumferential direction center position (center line 44) of the tooth 16 is used as a reference, and the phase shift of the circumferential direction magnetic pole center position (center line 43) of the rotor 12 from the circumferential direction center position (center line 44) of the tooth 16 is denoted by θ.

[0038] Fig. Figure 7 is a waveform diagram showing the torque of the rotating electrical machine in a case where no current is applied. Fig. 7 shows the torque waveform of the rotor 12 when the rotor 12 is rotated through an electrical angle of 360°, that is, through a mechanical angle of 90° (= (360° / (8 / 2))) in a state where no current is applied to the coil 17 of the rotating electrical machine 10.

[0039] Here, a torque waveform without phase shift is shown with a dotted line, and a torque waveform with a phase shift θ is shown with a solid line. For the torque waveform without phase shift, the angle at which there is a cross section where the circumferential magnetic pole center position of the rotor 12 coincides with the circumferential center position of the tooth 16 is defined as an initial angle of 0°.

[0040] For the torque waveform with the phase shift θ, the angle when there is a cross section in which 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 defined as an initial angle of 0°.

[0041] As in Fig. As shown in Figure 7, the torque of the rotating electric machine has a torque pulsation containing a main component that oscillates six times, as in the magnetic gear torque described above.

[0042] Also, the principle for determining the number of times (sequence) of oscillation of the rotating electric machine 10 is the same as in the case of the magnetic gear 20, except that the pole pieces 29 arranged at regular intervals correspond to the teeth 16. That is, the number of times of torque pulsation in a case where the rotor 12 rotates 360° in mechanical angle 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.

[0043] In this case, the lowest common multiple M(8, 12) has a value of 24, and the torque of the rotating electrical machine contains a component that oscillates 24K (K is a natural number) times in a mechanical angular range of 360°. Consequently, the torque of the rotating electrical machine oscillates 6K (= (24K / (8 / 2)) times in the electrical angular range of 360°, and a component that oscillates six times at K = 1 is included in a large value, which is consistent with the result obtained in Fig. 7 is shown.

[0044] In the magnetic gear device 100, the rotor 12 of the rotating electric machine 10 and the first rotor (inner magnet tube 23) of the magnetic gear 20 are connected, and a combined torque of the rotating electric machine torque and the magnetic gear torque is the total torque.

[0045] In the present embodiment, the lowest common multiple LCM of the number of first permanent magnets 25 of the first rotor (inner magnet tube 23) of the magnetic gear 20 and the number of pole pieces 29 coincides with the lowest common multiple M of the number of poles of the rotor 12 and the number of teeth 16 of the rotating electric machine 10.

[0046] That is, the principal order component of the torque pulsation per one revolution (rotation through a mechanical angle of 360°) of the first rotor (inner magnetic tube 23) of the magnetic gear 20 and the principal order component of the torque pulsation per one revolution (rotation through a mechanical angle of 360°) of the rotor 12 of the rotating electrical machine 10 are both twenty-four and coincide with each other.

[0047] Consequently, the torque pulsation of the rotating electric machine torque and the torque pulsation of the magnetic gear torque cancel each other out, so that they are reduced.

[0048] The torque pulsations change with the relative relationship of two positional relationships, as shown below. The first is the positional relationship between the pole pieces 29 of the magnetic gear 20 and the teeth 16 of the rotating electric machine 10. The second is the positional relationship between the permanent magnets 13 of the rotor 12 of the rotating electric machine 10 and the first permanent magnets 25 of the first rotor (inner magnet tube 23) of the magnetic gear 20, connected by the shaft (rotating shaft 11) to the rotor 12 of the rotating electric machine 10.

[0049] That is, the phase θ by which the circumferential magnetic pole center of the rotor 12 is shifted from the circumferential center position of the tooth 16 when the circumferential magnetic pole center of the first rotor (inner magnetic tube 23) coincides with the circumferential magnetic pole center of the stator (magnetic material tube 30), that is, the circumferential center position of the pole piece 29, is used as a parameter which is a predetermined angle, so that it becomes possible to prescribe the above relative relation which has a relation to the phase of the torque pulsation.

[0050] The Fig. The state shown in Figure 4 corresponds to the state when the circumferential magnetic pole center of the first rotor (inner magnet tube 23) coincides with the circumferential center position of the pole piece 29. Then, in this 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 tooth 16 is adjusted (see Fig. 6). Consequently, torque pulsation is effectively reduced, so that speed fluctuation due to torque pulsation can be suppressed.

[0051] Fig. 8 is a waveform diagram showing the torque of the rotating electric machine, the magnetic gear torque, and a combined torque in the magnetic gear device 100 in a case where no current is applied. In this case, a torque waveform (broken line) of the rotating electric machine 10, a torque waveform (dotted line) of the magnetic gear 20, and a combined torque waveform (solid line) obtained by adding both waveforms are shown, with the phase shift θ set to 21°.

[0052] As in Fig. 8, the magnitude Tα of the torque pulsation of the combined torque waveform, that is, the difference (PP) between the maximum value and the minimum value of the waveform, becomes significantly smaller than those of the torque waveform of the rotating electric machine 10 and the torque waveform of the magnetic gear 20, and hence the torque pulsation is significantly reduced.

[0053] Fig. 9 is a waveform diagram showing a change in torque pulsation of the combined torque with respect to the phase shift θ of the rotor 12 of the rotating electrical machine 10 in the magnetic gear device 100. Here, the phase shift θ changes in a range of one period of a component oscillating six times per electrical angle of 360°, which is a main component of the torque pulsation in the rotating electrical machine torque and magnetic gear torque, that is, in an electrical angle range of 60° (= (360 / 6)). Then, the change in the magnitude (PP) of the torque pulsation with respect to the phase shift θ is shown.

[0054] The smaller of the torque pulsation strength of the rotating electrical machine torque and the torque pulsation strength of the magnetic gear torque is denoted by Tβ. With reference to Fig. 6 and Fig. 7 In this case, Tβ is the strength of the torque pulsation of the magnetic gear torque and is approximately 5.0.

[0055] As in Fig. As shown in Figure 9, with θ defined as the electrical angle, the torque pulsation of the combined torque has a minimum value Tα in the vicinity of θ = 21° and becomes smaller than the torque pulsations of the magnetic gear torque and the rotating electrical machine torque in a range of θ (12.3° < θ < 25.5°).

[0056] The range of phase shift θ in which the torque pulsation reduction effect is obtained varies depending on features such as the shapes and arrangements of the permanent magnets and magnetic elements (pole pieces, teeth, etc.) of the rotor. Therefore, the range of θ in which the reduction effect is generally expected is discussed below.

[0057] Fig. 10 shows amplitudes in a frequency analysis result of the magnetic gear torque in the magnetic gear device 100. Fig. 11 shows amplitudes in a frequency analysis result of the torque of the rotating electric machine in the magnetic gear device 100.

[0058] As described above, the main components of the torque pulsations of the magnetic gear torque and the rotating electric machine torque include components of multiples of the lowest common multiples of the numbers of permanent magnets (25 and 13) and magnetic elements (teeth 16 and pole pieces 29), and in particular, the 1-fold components and the 2-fold components are dominant. In the present embodiment, the orders of the torque pulsation in an electrical angle range of 360° are denoted by 6K, and therefore, it can be seen that a sixth-order component (K = 1) and a twelfth-order component (K = 2) are dominant. Furthermore, it is well known that these 1-fold (K = 1) and 2-fold (K = 2) components are dominant in many structures, and therefore, the main focus is on reducing these two components.The strength relationship between the two components differs depending on the structures of the rotating electric machine 10 and the magnetic gear 20.

[0059] Fig. Figure 12 is a waveform diagram showing a sixth-order torque component in a generalized manner in the magnetic gear device 100. Here, only a sixth-order component is extracted from the magnetic gear torque and the rotating electric machine torque, and its torque waveform, generalized with its amplitude defined as 1, is shown in an electrical angular range of 360°. In this case, the torque pulsation intensity TA has a value of 2.0.

[0060] Fig. Figure 13 is a waveform diagram showing a twelfth-order torque component in a generalized manner in the magnetic gear device 100. Here, only a twelfth-order component is extracted from the magnetic gear torque and the rotating electric machine torque, and its torque waveform, generalized with its amplitude defined as 1, is shown in an electrical angular range of 360°. In this case, the torque pulsation strength TB has a value of 2.0.

[0061] In Fig. 12 and Fig. 13, a torque waveform whose maximum value is at an initial angle is shown with a dotted line, and a torque waveform with a phase shifted by the phase shift θ is shown with a solid line.

[0062] As described above, in the present embodiment, when obtaining a combined torque by adding the rotating electric machine torque and the magnetic gear torque, the phase shift θ of the circumferential direction magnetic pole center position of the rotor 12 from the circumferential direction center position of the tooth 16 is adjusted, so that the torque pulsation can be effectively reduced.

[0063] In Fig. 12 and Fig. 13, the torque waveform without phase shift (dotted line) is assumed to be the magnetic gear torque, the torque waveform with the phase shift θ (solid line) is assumed to be the torque of the rotating electric machine, and both waveforms are added, so that the torque waveforms of a sixth-order component and a twelfth-order component of a combined torque can be generated.

[0064] Fig. 14 is a waveform diagram showing torque pulsations of a sixth-order component and a twelfth-order component of the combined torque in a generalized manner in the magnetic gear device 100.

[0065] In Fig. 14 shows a change in torque pulsation with respect to the phase shift θ for each of the combined torque of the sixth-order component and the combined torque of the twelfth-order component calculated on the basis of Fig. 12 and Fig. 13 are generated. Thus, in this case, the phase shift θ is changed within a range of one period of a component that oscillates six times per electrical angle of 360°, which is a major component of torque pulsation in the rotating electric machine torque and magnetic gear torque, i.e., within an electrical angle range of 60° (= (360 / 6)). Then, the change in the magnitude (PP) of the torque pulsation with respect to the phase shift θ is shown.

[0066] With θ defined as the electrical angle, the torque pulsation of the combined torque of the sixth-order component becomes smaller than the torque pulsations TA, TB (= 2.0) of the torques before combination, in a range of 20° < θ < 40°. Furthermore, the torque pulsation of the combined torque of the twelfth-order component becomes smaller than the torque pulsations TA, TB (= 2.0) of the torques before combination, in a range of 10° < θ < 20° and 40° < θ < 50°.

[0067] That is, it is found that the torque pulsation of the combined torque of the sixth-order or twelfth-order component becomes smaller than the torque pulsation of the torque before the combination, in a θ range of 10° < θ < 50°.

[0068] The range of θ (12.3° < θ < 25.5°) found in Fig. 9 is an example based on the configurations of the rotating electric machine 10 and the magnetic gear 20 of the magnetic gear device 100 according to the present embodiment, and is included in the above θ range (10° < θ < 50°). Therefore, it can be described that the reduction effect is exhibited due to the combination.

[0069] In the present embodiment, the least common multiple M of the number of poles of the rotor 12 and the number of teeth 16 of the rotating electric machine 10 is set to the order of torque pulsation, so that components that oscillate M times and 2M times per rotation of the rotor 12 by a mechanical angle of 360° can be reduced.

[0070] Then, the above discussion based on the electrical angle is applied to the mechanical angle, so that the range of phase shift φ (mechanical angle) in which the torque pulsation can be reduced is obtained as (360 / M / 6)° < φ < ((360 / M / 6)×5))°.

[0071] That is, the torque pulsation is effectively reduced with such a positional relationship that the circumferential magnetic pole center of the rotor 12 is shifted from the circumferential center position of the tooth 16 by the phase (mechanical angle) φ in a range of (360 / M / 6)° < φ < ((360 / M / 6)×5))° when the circumferential magnetic pole center of the first rotor (inner magnet tube 23) coincides with the circumferential center position of the fixed pole piece 29.

[0072] As described above, in the present embodiment, the lowest common multiple LCM of the number N of pole pieces 29 and the number of poles of the first rotor (inner magnet tube 23) of the magnetic gear 20 coincides with the lowest common multiple M of the number of poles of the rotor 12 and the number of teeth 16 of the rotating electric machine 10.

[0073] Consequently, the magnetic gear device 100, which is a combination of the magnetic gear 20 and the rotating electric machine 10, can reduce the torque pulsation to be output, thus suppressing the speed fluctuation on the output side. Furthermore, special machining is not required for the first and second permanent magnets 25 and 27 to be used in the magnetic gear device 20, and therefore the magnetic gear device 100 can be manufactured easily and at low cost.

[0074] In addition, when the circumferential magnetic pole center of the first rotor (inner magnet tube 23) coincides with the circumferential center position of the fixed pole piece 29, the circumferential magnetic pole center of the rotor 12 is phase-shifted from the circumferential center position of the tooth 16 by a predetermined angle, so that the torque pulsation of the rotating electrical machine 10 and the torque pulsation of the magnetic gear 20 are reduced together.

[0075] Consequently, the torque pulsation of the combined torque output from the magnetic gear device 100 is effectively reduced, so that speed fluctuation on the output side is suppressed.

[0076] Furthermore, in the present embodiment, the number of poles of the first rotor (inner magnetic tube 23) of the magnetic gear 20 matches the number of poles of the rotor 12 of the rotating electric machine 10. Therefore, the design can be made to use products with the same specifications for the permanent magnets 13 of the rotor 12 of the rotating electric machine 10 and the first permanent magnets 25 of the first rotor (inner magnetic tube 23) of the magnetic gear 20, so that the manufacturing cost can be reduced.

[0077] In addition, in the magnetic gear device 100, normally, from the viewpoint of output power and efficiency, the necessary specifications for the rotating electric machine 10 are first determined, and then the number of poles of the rotor 12 and the number of teeth 16 are determined accordingly.

[0078] Next, the magnetic gear 20 is selected so that the torque pulsation of the magnetic gear torque and the torque pulsation of the rotating electric machine torque are reduced by canceling each other out. That is, the main order of the torque pulsation generated by the magnetic gear 20 is equal to or greater than the order of the torque pulsation generated by the rotating electric machine 10.

[0079] In the magnetic gear 20, it is desirable that the number of poles of the first rotor (inner magnetic tube 23) connected to the output shaft of the rotating electric machine 10 be equal to or greater than the number of poles of the rotor 12 of the rotating electric machine 10. As described above, among the torque pulsation orders of the magnetic gear 20, the least common multiple LCM of the number N of pole pieces 29 and the number of poles of the first rotor (inner magnetic tube 23) is dominant.

[0080] Therefore, in a case where the number of poles of the first rotor (inner magnetic tube 23) is smaller than the number of poles of the rotor 12 of the rotating electric machine 10, a component for an order smaller than the orders of the components of the torque pulsation generated by the rotating electric machine 10 may increase, so that the effect of reducing the torque pulsation cannot be obtained as a whole.

[0081] The present embodiment has shown the magnetic gear device 100 in which the rotating electric machine 10 having eight poles and twenty slots and the magnetic gear 20 having the first rotor (inner magnetic tube 23) having eight poles constituting a few-pole mechanism, the second rotor (outer magnetic tube 26) having forty poles constituting a multi-pole mechanism, and twenty-four pole pieces 29 constituting the magnetic material tube 30 are combined.

[0082] To generalize this example, if X and Y are defined as integers, the magnetic gear 20 is discussed below in which the number of poles of the first rotor (inner magnet tube 23) has a value of 2X, the number of poles of the second rotor (outer magnet tube 26) has a value of 2Y, and the number of pole pieces 29 has a value of (X + Y).

[0083] In this magnetic gear 20, the following applies: While the first rotor (inner magnetic tube 23) rotates 360° in the electrical angle, i.e., rotates (360 / X)° in the mechanical angle, the magnetic gear torque oscillates the same number of times as (lowest common multiple LCM(2X, (X + Y)) / X). ​​Therefore, the number of times the magnetic gear torque oscillates while the first rotor (inner magnetic tube 23) completes one revolution is (LCM(2X,(X+Y)) / X)×(360 / (360 / X))=LCM(2X,(X+Y)).

[0084] It is therefore found that when the lowest common multiple M of the number of poles of the rotor 12 and the number of teeth 16 of the rotating electric machine 10 coincides with the lowest common multiple LCM of the number of poles of the first rotor (inner magnet tube 23) connected to the rotating shaft 11 of the rotating electric machine 10 and the number of pole pieces 29, it becomes possible to make such an adjustment that the torque pulsation of the magnetic gear torque and the torque pulsation of the rotating electric machine torque can be reduced by cancellation.

[0085] In the above embodiment, the rotating shaft 11 of the rotating electric machine 10 is formed integrally with the input portion 21 of the magnetic gear 20. However, the present invention is not limited to this.

[0086] Fig. 15 is a vertical sectional view showing the configuration of the magnetic gear device 100 according to another example of Embodiment 1.

[0087] As in Fig. As shown in Figure 15, the rotating shaft 11 of the rotating electrical machine 10 is connected to the input section 21 of the magnetic gear 20 via a rotational force connection mechanism 36, such as a shaft coupling. The connection mechanism 36 may also be a belt, a mechanical gear, a magnetic coupling, or the like, instead of a shaft coupling.

[0088] Therefore, even in a case where the rotating shaft 11 of the rotating electric machine 10 is connected to the input portion 21 of the magnetic gear 20 via the rotational force connecting mechanism 36, the same effects as in the above embodiment 1 are obtained.

[0089] In the above embodiment, the example in which the pole pieces 29 are fixed is shown. However, the pole pieces 29 may also be rotatable, so that phase adjustment can be performed arbitrarily, thus achieving the same effects. Embodiment 2

[0090] In the above Embodiment 1, the reduction of torque pulsation in the magnetic gear device 100 is described in a case where no current is applied. In the present Embodiment 2, the reduction of torque pulsation in the magnetic gear device 100 is described in a case where current is applied to the rotating electrical machine 10. The structure of the magnetic gear device 100 in the present embodiment is the same as that described in Fig. 1 to Fig. 3 in the above embodiment 1.

[0091] Fig. 16 is a waveform diagram showing the rotating electric machine torque, the magnetic gear torque, and the combined torque in a magnetic gear device according to Embodiment 2 when power is applied.

[0092] As described above, in the magnetic gear device 100, the rotor 12 of the rotating electric machine 10 and the first rotor (inner magnet tube 23) of the magnetic gear 20 are connected, and a combined torque of the rotating electric machine torque and the magnetic gear torque is the total torque.

[0093] Fig. 16 shows a torque waveform (broken line) of the rotating electric machine 10, a torque waveform (dotted line) of the magnetic gear 20, and a combined torque waveform (solid line) obtained by adding both waveforms in a case where current is applied to the coils 17 of the rotating electric machine 10.

[0094] The magnetic gear torque waveform is the same as the torque waveform shown in Fig. 5 in the above embodiment 1, that is, the torque pulsation occurs six times while the first rotor (inner magnet tube 23) rotates through an electrical angle of 360°.

[0095] As described above, since the least common multiple LCM of the number of poles of the first rotor (inner magnet tube 23), which is the number of first permanent magnets 25 and the number of pole pieces 29, is 24, the magnetic gear torque oscillates 6K (= (24K / (8 / 2)) times in an electrical angular range of 360°. Consequently, a component oscillating six times at K = 1 is included with a large value.

[0096] As in Fig. As shown in Figure 16, it can be seen that the torque of the rotating electrical machine is dominated by a sixth-order torque pulsation component that oscillates six times while the rotor 12 rotates through an electrical angle of 360°. It is well known that in the rotating electrical machine 10, when current is applied, the torque pulsation component increases, oscillating (6×N1) times (N1 is a natural number) during the 360° rotation in the electrical angle.

[0097] As in Fig. 16, the magnitude Tγ of the torque pulsation of the combined torque waveform, that is, the difference (PP) between the maximum value and the minimum value of the waveform, becomes significantly smaller than those of the torque waveform of the rotating electric machine 10 and the torque waveform of the magnetic gear 20, and hence the torque pulsation is significantly reduced.

[0098] Also in the present Embodiment 2, as in the above Embodiment 1, when the main order of the torque pulsation of the rotating electric machine 10 agrees with the main order of the torque pulsation of the magnetic gear 20, the effect of reducing the torque pulsation in the combined torque is obtained by phase adjustment.

[0099] That is, when the condition that the number of poles of the rotor 12 of the rotating electric machine 10 × (3 × N1) coincides with the least common multiple LCM of the number of poles of the first rotor (inner magnet tube 23) connected to the rotating shaft 11 of the rotating electric machine 10 and the number of pole pieces 29 is satisfied, the effect of reducing the torque pulsation is obtained when power is applied to the rotating electric machine 10.

[0100] In this case, the least common multiple LCM (= 24) is three times the number of poles (= 8) of the rotor 12 of the rotating electrical machine 10, and hence it satisfies the above condition at N1 = 1, so that the effect of reducing the torque pulsation is obtained.

[0101] The phase of the torque pulsation of the rotating electric machine 10 when current is applied changes depending on the states of the amplitude and phase of the current, as well as the sectional shape of the rotating electric machine 10. Accordingly, the phase adjustment is performed by arranging such that torque pulsations are canceled in desired states of the amplitude and phase of the current where oscillation reduction is required.

[0102] For example, a drive motor for a vehicle is often used in a low to medium torque range operation, and therefore the phase relation is selected so that torque pulsations are canceled in the condition where the amplitude and phase of the current are in the above torque range.

[0103] The phase adjustment at this time can also be performed by adjusting the phase (phase shift θ) between the circumferential magnetic pole center of the rotor 12 and the circumferential center position of the tooth 16 when the circumferential magnetic pole center of the first rotor (inner magnet tube 23) coincides with the circumferential center position of the pole piece 29, as in the above embodiment 1.

[0104] Then, by performing phase adjustment so that the torque pulsation of the rotating electric machine 10 and the torque pulsation of the magnetic gear 20 are reduced together, the torque pulsation is effectively reduced, so that speed fluctuation due to the torque pulsation can be suppressed.

[0105] The condition that the lowest common multiple LCM of the number N of pole pieces 29 and the number of poles of the first rotor (inner magnet tube 23) of the magnetic gear 20 agrees with the lowest common multiple M of the number of poles of the rotor 12 and the number of teeth 16 of the rotating electric machine 10 as described in the above Embodiment 1 is defined as a first condition.

[0106] Then, the condition that the lowest common multiple LCM of the number N of pole pieces 29 and the number of poles of the first rotor (inner magnetic tube 23) of the magnetic gear 20 coincides with the number of poles of the rotor 12 of the rotating electric machine 10 × (3 × N1) as described in the present embodiment is defined as a second condition. With the first condition and the second condition set as described above, if at least one of the first condition and the second condition is satisfied, the effect of reducing torque pulsation is obtained.

[0107] In the magnetic gear device 100 used in the present embodiment, the lowest common multiple LCM (= 24) of the number N of pole pieces 29 and the number of poles of the first rotor (inner magnet tube 23) of the magnetic gear 20 coincides with the lowest common multiple M (= 24) of the number of poles of the rotor 12 and the number of teeth 16 of the rotating electric machine 10, and it coincides with three times the number of poles of the rotor 12.

[0108] Therefore, both the first and second conditions are met. Consequently, the magnetic gear device 100 can achieve the effect of reducing torque pulsation in both cases: when no current is applied and when current is applied. Embodiment 3

[0109] Fig. 17 is a vertical sectional view showing the configuration of a magnetic gear device according to Embodiment 3.

[0110] As in Fig. 17, a magnetic gear device 100A is formed as a drive unit, which has the rotating electric machine 10 and a magnetic gear 20A.

[0111] The rotating electric machine 10 is the same as in Embodiment 1 above. The magnetic gear 20A includes the inner magnetic tube 23 forming a few-pole mechanism with a smaller number of magnetic poles, an outer magnetic tube 26A forming a multi-pole mechanism with a larger number of magnetic poles, and a magnetic material tube 30A disposed between the inner magnetic tube 23 and the outer magnetic tube 26A, with magnetic gaps 31 of both the inner magnetic tube 23 and the outer magnetic tube 26A interposed therebetween.

[0112] Their transverse sectional view is the same as that in Fig. 3, but a combination of the number of first permanent magnets 25 of the inner magnetic tube 23, the number of second permanent magnets 28 of the outer magnetic tube 26A, and the number of pole pieces 29 of the magnetic material tube 30A is different. In the magnetic gear 20A, the inner magnetic tube 23, the outer magnetic tube 26A, and the magnetic material tube 30A are concentrically arranged. One of the three tubes is used as a first rotor connected to the input section 21, another is used as a second rotor connected to the output section 22, and the remaining one is used as a stator.

[0113] In the present embodiment, the inner magnet tube 23 is used as the first rotor, the magnetic material tube 30A is used as the second rotor, and the outer magnet tube 26A is used as the stator.

[0114] The remaining configurations are the same as in Embodiment 1 above.

[0115] That is, in the present embodiment, the rotor 12 of the rotating electric machine 10 and the first rotor (inner magnetic tube 23) of the magnetic gear 20A are coaxially arranged, and the first rotor (inner magnetic tube 23) of the magnetic gear 20A rotates together with the rotating shaft 11 of the rotating electric machine 10.

[0116] Consequently, a magnetic flux is applied to the pole pieces 29 of the second rotor (magnetic material tube 30A), which is located between the stator (outer magnet tube 26A) and the first rotor (inner magnet tube 23). The second rotor (magnetic material tube 30A) then rotates in the same direction as the first rotor (inner magnet tube 23).

[0117] Consequently, in the magnetic gear device 100A, a driving force generated by the rotating electric machine 10 is subjected to a speed reduction and a torque increase or a speed increase and a torque decrease by the magnetic gear 20A, and then the resultant power is output from the output portion 22 corresponding to an output shaft of the magnetic gear 20A.

[0118] The combination of the number of first permanent magnets 25 of the inner magnetic tube 23, the number of second permanent magnets 28 of the outer magnetic tube 26A, and the number N of pole pieces 29 of the magnetic material tube 30A in the magnetic gear 20A is shown below. When X and Y (>X) are defined as natural numbers, the number of first permanent magnets 25 of the inner magnetic tube 23 is 2X, the number of second permanent magnets 28 of the outer magnetic tube 26A is 2Y, and the number N of pole pieces 29 of the magnetic material tube 30A is (X + Y).

[0119] While the first rotor (inner magnet tube 23) rotates relative to the second rotor (magnetic material tube 30) by 360° in electrical angle, i.e. (360 / X+360 / Y)° in mechanical angle, the magnetic gear torque oscillates the same number of times as the value obtained by dividing the least common multiple LCM of the number N of pole pieces 29 and the number of poles of the first rotor (inner magnet tube 23) by X, i.e. (LCM(2X, (X + Y)) / X) times. That is, the number of times the magnetic gear torque oscillates while the first rotor (inner magnetic tube 23) oscillates 360° in mechanical angle is (LCM(2X, (X + Y)) / X)×(360 / (360 / X+360 / Y)) = LCM(2X, (X + Y))×(Y / (X + Y)).

[0120] Therefore, the magnetic gear 20A is configured by determining a combination of the number of first permanent magnets 25 of the inner magnetic tube 23, the number of second permanent magnets 28 of the outer magnetic tube 26A, and the number N of pole pieces 29 of the magnetic material tube 30A such that the lowest common multiple M of the number of poles of the rotor 12 and the number of teeth 16 of the rotating electrical machine 10 is LCM(2X, (X + Y))×(Y / (X + Y)).

[0121] That is, the value obtained by multiplying the least common multiple LCM of the number N of pole pieces 29 and the number of poles of the first rotor (inner magnetic tube 23) by ((number of poles of the stator (outer magnetic tube 26A)) / N) is defined as a first value, and the specification is made so that the first condition is satisfied that the first value coincides with 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.

[0122] Therefore, in a case where no current is applied in the rotating electric machine 10, when the main order of the torque pulsation of the rotating electric machine 10 and the main order of the torque pulsation of the magnetic gear 20A agree with each other, these torque pulsations can be canceled to be reduced by phase adjustment, so that the torque pulsation in the combined torque is reduced.

[0123] In this case, as in the above embodiment 1, the phase (phase shift θ) between the circumferential direction magnetic pole center of the rotor 12 and the circumferential direction center position of the tooth 16 when the circumferential direction magnetic pole center of the first rotor (inner magnetic tube 23) coincides with the circumferential direction magnetic pole center of the stator (outer magnetic tube 26A) is adjusted.

[0124] Then, by performing phase adjustment so that the torque pulsation of the rotating electric machine 10 and the torque pulsation of the magnetic gear 20 are reduced together, the torque pulsation is effectively reduced, so that speed fluctuation due to the torque pulsation can be suppressed.

[0125] Accordingly, the magnetic gear device 100A can reduce the torque pulsation to be output, so that a speed fluctuation on the output side can be suppressed.

[0126] In addition, as in the above embodiment 1, special processing of the first and second permanent magnets 25 and 28 to be used in the magnetic gear 20A is not necessary, and therefore the magnetic gear device 100A can be manufactured easily and at low cost.

[0127] The configuration of the magnetic gear device 100A may be set to satisfy the second condition that the first value obtained by multiplying the least common multiple LCM of the number N of pole pieces 29 and the number of poles of the first rotor (inner magnetic tube 23) by ((number of poles of the stator (outer magnetic tube 26A)) / N) coincides with the number of poles of the rotor 12 of the rotating electrical machine 10 × (3 × N1).

[0128] In this case, as shown in the above embodiment 2, the effect of reducing the torque pulsation is achieved in a case where current is applied in the rotating electrical machine 10.

[0129] That is, when at least one of the first condition and the second condition is satisfied, the effect of reducing torque pulsation is achieved through phase-related adjustment. Furthermore, when both the first condition and the second condition are satisfied, the magnetic gear device 100A can achieve the effect of reducing torque pulsation both in the case where current is not applied and in the case where current is applied.

[0130] Furthermore, in the present embodiment, a structure is adopted in which the magnetic material tube 30A having pole pieces 29 rotates as the first rotor, so that the gear ratio can be improved compared to the above Embodiment 1. Furthermore, since the outer magnetic tube 26A at the outermost peripheral portion of the magnetic gear 20A is the stator, the structure can be simplified and the manufacturing cost can be reduced.

[0131] In addition, it is desirable that the magnetic gear 20A satisfy at least a condition that the number of poles of the first rotor (inner magnetic tube 23) connected to the output shaft of the rotating electric machine 10 is equal to or greater than the number of poles of the rotor 12 of the rotating electric machine 10, and a condition that the number of pole pieces 29 of the second rotor (magnetic material tube 30A) is equal to or greater than the number of teeth 16 of the rotating electric machine 10.

[0132] Consequently, it can be ensured that the magnetic gear 20A is selected so that the main order of the torque pulsation generated by the magnetic gear 20A becomes equal to or greater than the order of the torque pulsation generated by the rotating electric machine 10, so that the torque pulsation can be suppressed from the combined torque output from the magnetic gear device 100A.

[0133] In the above embodiment, an example is shown in which the stator (outer magnetic tube 26A) is fixed. However, the stator (outer magnetic tube 26A) may be rotatable, so that phase adjustment can be performed arbitrarily, thus achieving the same effects.

[0134] In the above embodiments, the example shown is that the rotating shaft 11 of the rotating electrical machine 10 and the rotating shaft (input portion 21) of the magnetic gear 20, 20A are coaxially arranged, but the present invention is not limited to this. The same effects are achieved as long as the rotating shaft 11 of the rotating electrical machine 10 and the input portion 21 of the magnetic gear 20, 20A are connected. Embodiment 4

[0135] In the present Embodiment 4, the rotor 12 of the rotating electric machine 10 and the first rotor (inner magnet tube 23) of the magnetic gear 20 are integrally formed in the magnetic gear device 100A of the above Embodiment 3.

[0136] Fig. 18 is a vertical sectional view showing the configuration of a magnetic gear device according to Embodiment 4.

[0137] As in Fig. As shown in Figure 18, a magnetic gear device 100B is configured as a drive unit including a rotating electric machine 10A and a magnetic gear 20B. In this case, a rotor 12A of the rotating electric machine 10A is integrally formed with the first rotor (inner magnetic tube 23A) of the magnetic gear 20B. The other configurations are the same as in Embodiment 3 above.

[0138] In the present embodiment, a rotor core material is shared between the magnetic gear 20B and the rotating electric machine 10A, so structural elements can be further reduced. Consequently, manufacturing costs can be further reduced.

[0139] Also in this case, when at least one of the first condition and the second condition specified in the above embodiment 3 is satisfied, as in the above embodiment 3, the torque pulsation can be reduced by phase adjustment, so that a speed fluctuation on the output side can be suppressed.

[0140] When the value obtained by multiplying the least common multiple LCM of the number N of pole pieces 29 and the number of poles of the first rotor (inner magnetic tube 23A) by ((number of poles of the stator (outer magnetic tube 26A)) / N) is defined as a first value, the first condition is a condition that the first value agrees with 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. The second condition is a condition that the first value agrees with the number of poles of the rotor 12 of the rotating electrical machine 10 × (3 × N1).

[0141] In the above embodiment 4, the structure is shown in which the rotating electric machine 10A and the magnetic gear 20B are housed in the same frame 18A. However, they may be housed in separate frames.

[0142] In the above embodiments 1 to 4, the example shown is that the magnetic gear 20, 20A, 20B is a speed-reducing gear that performs speed reduction and torque increase. However, in a case where the outer magnetic tube 26, which is a multi-pole mechanism of the magnetic gear 20, 20A, 20B, is used as the first rotor and connected to the rotating shaft 11 of the rotating electrical machine 10, 10A, a speed-increasing gear that performs speed increase and torque decrease can be obtained. In this case, too, the same effects as in the above embodiments are obtained. Embodiment 5

[0143] Fig. 19 is a vertical sectional view showing the configuration of a magnetic gear device according to Embodiment 5.

[0144] As in Fig.19, a magnetic gear device 100C is formed as a drive unit, which has the rotating electric machine 10 and a magnetic gear 20C.

[0145] In the present embodiment, in the magnetic gear 20C, an inner magnetic tube 23B, the outer magnetic tube 26A, and a magnetic material tube 30B are coaxially arranged, the magnetic material tube 30B is used as a first rotor, one of the inner magnetic tube 23B and the outer magnetic tube 26A is used as a second rotor, and the remaining one is used as a stator.

[0146] Here, a case is shown where the inner magnetic tube 23B is used as the second rotor and the outer magnetic tube 26A is used as the stator. The other configurations are the same as in Embodiment 1 above.

[0147] In this case, the value obtained by multiplying the lowest common multiple of the number N of pole pieces 29 and the number of poles of the second rotor (inner magnet tube 23B or outer magnet tube 26A) by ((number of poles of the stator (outer magnet tube 26A or inner magnet tube 23B)) / N) is defined as a first value.

[0148] Then the specification is made such that the first condition that the first value corresponds to the lowest common multiple M of the number of poles of the rotor 12 and the number of teeth 16 of the rotating electrical machine 10.

[0149] Therefore, in a case where no current is applied in the rotating electric machine 10, when the main order of the torque pulsation of the rotating electric machine 10 and the main order of the torque pulsation of the magnetic gear 20C agree with each other, these torque pulsations can be canceled to be reduced by phase adjustment, so that the torque pulsation in the combined torque is reduced.

[0150] In this case, as in Embodiment 1 above, the phase (phase shift θ) between the circumferential magnetic pole center of the rotor 12 and the circumferential center position of the tooth 16 when the circumferential magnetic pole center of the first rotor (magnetic material tube 30B), that is, the circumferential center position of the pole piece 29, coincides with the circumferential magnetic pole center of the stator (outer magnetic tube 26A or inner magnetic tube 23B) is adjusted.

[0151] Thus, by performing phase adjustment so that the torque pulsation of the rotating electric machine 10 and the torque pulsation of the magnetic gear 20C are reduced together, the torque pulsation is effectively reduced, so that a speed fluctuation due to the torque pulsation can be suppressed.

[0152] The setting may be such that the second condition is satisfied that the first value matches the number of poles of the rotor 12 of the rotating electrical machine 10 × (3 × N1). In this case, as shown in Embodiment 2 above, the effect of reducing torque pulsation is achieved in a case where power is applied to the rotating electrical machine 10. That is, when at least one of the first condition and the second condition is satisfied, the effect of reducing torque pulsation is achieved by phase-related adjustment.

[0153] In the above embodiments, the number of permanent magnets constituting each magnetic pole of the rotating electric machine 10 and the magnetic gear 20, 20A, 20B, 20C is not limited to one. The same effects are also achieved in a case where the permanent magnet is divided in the magnetization direction, a direction perpendicular to the magnetization direction, the axial direction, or any other direction.

[0154] In the above examples, the rotating electric machine 10 and the magnetic gear 20, 20A, 20B, 20C are of the radial type, with a magnetic gap formed in a direction perpendicular to the rotating shaft. The same effects are also achieved with the axial type, with a magnetic gap formed in a direction parallel to the rotating shaft.

[0155] In the above embodiments, the rotating electric machine 10 has eight poles and twelve slots. However, the same effects are also achieved with a configuration having a different number of poles and slots, as long as the relationship between the number of poles of the rotor and the number of pole pieces 29 of the magnetic gear 20, 20A, 20B, 20C satisfies the above-described condition, as shown in the above embodiments.

[0156] In Embodiment 1 above, the example shown is that the few-pole mechanism (inner magnetic tube 23) of the magnetic gear 20 has eight poles, the multi-pole mechanism (outer magnetic tube 26) has forty poles, and the number of pole pieces 29 is twenty-four. However, for example, these numbers can also be combined as follows.

[0157] If the number of poles Ns of the few-pole mechanism is smaller than the number of poles Nm of the multi-pole mechanism, Np is the number of pole pieces 29, and 1 and m are natural numbers, then (21 - 1)Np = Nm ± (2m - 1)Ns is satisfied. Then, the numbers are combined to satisfy the torque pulsation reduction condition, as shown in the above embodiments. The same effects are obtained in this case as well.

[0158] In the above embodiments, the teeth 16, the pole pieces 29, and the permanent magnets 13, 25, 28 of the rotating electric machine 10 and the magnetic gear 20, 20A, 20B, 20C have the simplest shapes. However, the following shapes may also be used. For example, the teeth 16 and the pole pieces 29 may have shapes that widen or taper toward the magnetic gap, extending in the radial direction.

[0159] Bonded magnets can be used as permanent magnets 13, 25, 28, or two or more permanent magnets can be used per magnetic pole and embedded in a V-shape. In either case, the same effects are achieved as long as the pole arrangements relevant to the magnetic gaps have relationships similar to those in the above embodiments.

[0160] Although the invention has been described above in terms of various exemplary embodiments and implementations, it should be understood that the various features, aspects, and functionalities described in one or more of the individual embodiments are not limited in their applicability to the particular embodiment with which they are described, but instead may be applied - alone or in various combinations - to one or more of the embodiments of the invention.

[0161] It is therefore understood that numerous modifications not described by way of example may be used without departing from the scope of the present invention. For example, at least one of the components may be modified, added, or omitted. At least one of the components recited in at least one of the preferred embodiments may be selected and combined with the components recited in another preferred embodiment. List of reference symbols 10, 10A rotating electrical machine 11 Rotating shaft 12, 12A rotor 13 Permanent magnet 15 Stator 16 tooth 20, 20A magnetic gear 20B, 20C magnetic gear 21 Entrance area 22 Exit area 23, 23A, 23B inner magnet tube 25 first permanent magnet 26, 26A outer magnet tube 28 second permanent magnet 29 Pole piece 30, 30A, 30B magnetic material tube 31 Magnetic gap 100, 100A, 100B, 100C magnetic gear device θ, φ phase shift QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] JP 6 213 573 B2

[0006]

Claims

[1] Magnetic gear device comprising: - a magnetic gear comprising an inner magnetic tube having a plurality of first permanent magnets arranged on an outer circumference to form a few-pole mechanism, an outer magnetic tube having a plurality of second permanent magnets arranged on an inner circumference to form a multi-pole mechanism, and a magnetic material tube arranged between the inner magnetic tube and the outer magnetic tube, with magnetic gaps interposed therebetween from both the inner magnetic tube and the outer magnetic tube. The magnetic material tube has N pole pieces formed of a soft magnetic material and arranged at equal intervals therebetween in the circumferential direction, such that one of the inner magnetic tube, the outer magnetic tube, and the magnetic material tube is used as a first rotor connected to an input portion.another is used as a second rotor connected to an output region, and the remaining one is used as a stator; and, - a rotating electrical machine comprising a rotor having M1 permanent magnets and a stator having M2 teeth, wherein the magnetic gear is configured such that the input portion is connected to a rotary shaft of the rotating electrical machine and a supplied rotational force is transmitted to the output portion, and wherein at least one of a first condition that a first value based on the lowest common multiple of the number N of pole pieces and the number of poles of one of the first and second rotors coincides with the lowest common multiple M of M1 and M2, and a second condition that the first value coincides with a value obtained by multiplying M1 by a multiple of 3 is satisfied. [2] The magnetic gear device according to claim 1, wherein the phase between the circumferential magnetic pole center of the rotor and the circumferential center position of the tooth of the rotating electric machine when the circumferential magnetic pole center of the first rotor coincides with the circumferential magnetic pole center of the stator of the magnetic gear is adjusted so that a torque pulsation of the rotating electric machine and a torque pulsation of the magnetic gear are reduced together. [3] Magnetic gear device according to claim 1 or 2, wherein the magnetic material tube is used as the stator of the magnetic gear, and where the lowest common multiple of the number N of pole pieces and the number of poles of the first rotor is the first value. [4] The magnetic gear device according to claim 3, wherein, when the circumferential magnetic pole center of the first rotor coincides with the circumferential magnetic pole center position of the pole piece which is a magnetic pole of the stator, the circumferential magnetic pole center of the rotor of the rotating electric machine is phase-shifted from a circumferential magnetic pole center position of the tooth by a predetermined angle, so that a torque pulsation of the rotating electric machine and a torque pulsation of the magnetic gear are mutually reduced. [5] A magnetic gear device according to claim 4, wherein the predetermined angle is greater than (360 / M / 6) degrees and less than ((360 / M / 6)×5) degrees. [6] Magnetic gear device according to claim 1 or 2, wherein the magnetic material tube is used as the second rotor of the magnetic gear, and where a value obtained by multiplying the lowest common multiple of the number N of pole pieces and the number of poles of the first rotor by ((number of poles of the stator) / N) is the first value. [7] Magnetic gear device according to one of claims 1 to 6, wherein the following is satisfied: number of poles of the first rotor ≥ M1. [8] Magnetic gear device according to claim 7, wherein the following is satisfied: Number of poles of the first rotor = M1. [9] Magnetic gear device according to claim 1 or 2, wherein the magnetic material tube is used as the first rotor of the magnetic gear, and where a value obtained by multiplying the lowest common multiple of the number N of pole pieces and the number of poles of the second rotor by ((number of poles of the stator) / N) is the first value. [10] Magnetic gear device according to claim 9, wherein N ≥ M2 is satisfied. [11] Magnetic gear device according to one of claims 1 to 10, wherein the input portion of the magnetic gear is formed integrally with the rotary shaft of the rotating electrical machine.

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