Rotor and magnetic wave gear device

Abstract

Provided is a rotor having low magnetic resistance between magnetic poles.　This rotor (5) has magnet modules (52a, 52b, 52c) which are annularly disposed about a rotary shaft, wherein: the magnet modules each have a base (6) composed of magnetic substances, and two rotor magnets (7,8) which are disposed at an interval on the outer peripheral surface of the base in the rotation direction of the rotary shaft and which have poles different from each other; and the facing rotor magnets of two magnet modules adjacent to each other in the rotation direction have the same poles and are in close contact with each other.

Description

[Technical field]

[0001] The present application relates to a rotor and a magnetic wave gear device. [Background technology]

[0002] A magnetic wave gear device that integrates a magnetic reducer and a rotating machine is known as a generator for a wind power generation device. The magnetic wave gear device is composed of a low-speed rotor, a high-speed rotor that is arranged coaxially with the low-speed rotor, and a stator that has a stator winding and a permanent magnet. The magnetic wave gear device can change the rotation speed of the rotor in a non-contact manner without using a mechanical transmission that generates mechanical wear. Therefore, the magnetic wave gear device reduces the maintenance load for mechanical wear. Furthermore, when the magnetic wave gear device is used as a generator for a wind power generation device, it is possible to change the speed and generate electricity with a single device, which makes it possible to reduce the size and space of the power generation system.

[0003] A conventional magnetic wave gear device has a stator having multiple permanent magnets, a high-speed rotor having multiple rotor magnets, and magnetic pole piece A magnetic wave gear device has been disclosed in which a low-speed rotor having a rotor magnet is arranged concentrically with a low-speed rotor having a rotor magnet (see, for example, Patent Document 1). As the high-speed rotor of such a magnetic wave gear device, a rotor in which multiple magnet modules, each having a rotor magnet fixed to a base, are arranged in the circumferential direction, can be used. As such a rotor, a rotor in which the base of the magnet module is made of a magnetic material has been disclosed (see, for example, Patent Document 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2016-135014 A [Patent Document 2] JP 2019-30063 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in conventional rotors, the boundaries between magnet modules are also the boundaries between adjacent magnetic poles, resulting in large magnetic resistance between the magnetic poles. Therefore, even if a conventional rotor is applied to a magnetic wave gear device, there is a problem in that output is low due to the large magnetic resistance between the rotor's magnetic poles.

[0006] The present application has been made to solve the above-mentioned problems, and has an object to provide a rotor having a small magnetic resistance between the magnetic poles. [Means for solving the problem]

[0007] The rotor of the present application is a rotor in which magnet modules are arranged in a circular ring shape around the rotation axis. The magnet modules have a base made of a magnetic material and two rotor magnets with different poles arranged on the outer circumferential surface of the base with a gap in the rotation direction of the rotation axis, and the opposing rotor magnets of two magnet modules adjacent in the rotation direction have the same pole and are in close contact with each other. Effect of the Invention

[0008] In the rotor of the present application, the opposing rotor magnets of two magnet modules adjacent in the rotational direction have the same polarity and are in close proximity to each other, so that the magnetic resistance between the magnetic poles can be reduced. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a front view of a magnetic wave gear device according to a first embodiment. [Diagram 2] FIG. 2 is a perspective view of a magnet module according to the first embodiment. [Diagram 3] 1 is a cross-sectional view of a high-speed rotor according to a first embodiment. [Figure 4] FIG. 1 is a perspective view of a magnetic wave gear device according to a first embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, a rotor and a magnetic wave gear device according to an embodiment of the present invention will be described in detail with reference to the drawings. Note that the same reference numerals in each drawing indicate the same or corresponding parts.

[0011] Embodiment 1 FIG. 1 is a front view of a magnetic wave gear device according to a first embodiment. The magnetic wave gear device 1 of this embodiment has a cylindrical frame 2, a stator 3, a low-speed rotor 4, and a high-speed rotor 5. The stator 3 has a stator core 31 with a plurality of slots in the circumferential direction, a stator winding 32 arranged in the slots, and a stator magnet 33. The stator 3 is fixed to the frame 2 on the inner periphery side of the frame 2. The low-speed rotor 4 has a cylindrical low-speed rotor core arranged on the inner periphery side of the stator 3 with a gap therebetween. The high-speed rotor 5 is concentric with the rotating shaft 41 of the low-speed rotor 4 and arranged on the inner periphery side of the low-speed rotor core with a gap therebetween. The high-speed rotor 5 has a cylindrical high-speed rotor core 51 and magnet modules 52 arranged side by side in the circumferential direction. The low-speed rotor 4 is provided with a low-speed rotor end plate 42 that fastens the low-speed rotor core and the rotating shaft 41 on the outer side in the rotating shaft 41 direction than the high-speed rotor 5. As shown in Fig. 1, the low-speed rotor end plate 42 in this embodiment is composed of multiple spokes 42a. There are openings between the multiple spokes 42a.

[0012] Fig. 2 is a perspective view of a magnet module according to this embodiment. In Fig. 2, the direction indicated by the double-ended arrow is the rotation direction of the rotating shaft 41 of the magnetic wave gear device 1 shown in Fig. 1. The magnet module 52 has a base 6 and two rotor magnets 7, 8 with different poles arranged on the outer circumferential surface of the base 6 with a gap therebetween in the rotational direction. The base 6 has a plurality of electromagnetic steel plates 61 laminated in the axial direction of the rotating shaft. The plurality of electromagnetic steel plates 61 are fixed by a bottom plate 62 and end plates 63 having an L-shaped cross section, and fixing bolts 64.

[0013] The two rotor magnets 7 and 8 have opposite poles. For example, if the outer periphery of the rotor magnet 7 is an N pole, the outer periphery of the rotor magnet 8 is an S pole. As shown in Fig. 2, the two rotor magnets 7 and 8 are each composed of four magnet pieces divided into two in the rotational and axial directions. These magnet pieces are firmly fixed to the base 6 with, for example, an adhesive.

[0014] FIG. 3 is a cross-sectional view of a high-speed rotor according to this embodiment. In the high-speed rotor 5 according to this embodiment, magnet modules 52 are arranged in close contact with the outer circumferential surface of a cylindrical high-speed rotor core 51 in an annular shape. FIG. 3 shows a part of a cross section of the high-speed rotor 5 in which the magnet modules 52 are arranged in the rotation direction of the rotating shaft 41. In FIG. 3, the direction indicated by the double-ended arrow is the rotation direction of the rotating shaft 41 of the magnetic wave gear device 1 shown in FIG. 1. As shown in FIG. 3, the opposing rotor magnets of the magnet modules 52 adjacent in the rotation direction have the same pole and are in close contact with each other. Therefore, one magnetic pole is configured to straddle two magnet modules 52. In FIG. 3, the dashed lines indicate the boundaries of the magnetic poles. For example, one magnetic pole of N pole is configured by the N-pole rotor magnet 7 on the left side of the magnet module 52a arranged in the center and the N-pole rotor magnet 8 on the right side of the magnet module 52b arranged on the left side. Similarly, the S-pole rotor magnet 8 on the right side of the magnet module 52a located in the center and the S-pole rotor magnet 7 on the left side of the magnet module 52c located on the right side form one S-pole magnetic pole.

[0015] In the high-speed rotor 5 configured in this manner, the boundary between the magnetic poles is the center of the magnet module. Therefore, the base of the magnet module becomes the magnetic path between the magnetic poles, reducing the magnetic resistance between the magnetic poles. As a result, it is possible to suppress a decrease in the output of a magnetic wave gear device using this high-speed rotor.

[0016] In addition, because the base of the magnet module is made of electromagnetic steel plates laminated in the axial direction, the current path in the axial direction is interrupted, making it difficult for eddy currents to flow. Therefore, in this magnet module, eddy current loss caused by harmonic magnetic flux can be reduced.

[0017] FIG. 4 is a perspective view of a magnetic wave gear device according to this embodiment. As shown in FIG. 4, the low-speed rotor end plate 42 is composed of a plurality of spokes 42a. There are openings between the plurality of spokes 42a. As shown by the arrows in FIG. 4, the magnet module 52 can be passed through this opening and placed on the outer circumferential surface of the high-speed rotor core 51. When the high-speed rotor is assembled in this manner, the rotor magnets 7 and 8 are not incorporated in the high-speed rotor core 51 when the high-speed rotor core 51 is inserted into the inner circumferential side of the stator 3. Therefore, no magnetic attraction force is generated between the stator magnet 33 and the rotor magnets 7 and 8 when the high-speed rotor core 51 is inserted. As a result, no force perpendicular to the insertion direction is applied when the high-speed rotor core 51 is inserted into the stator 3, so that the high-speed rotor core 51 can be inserted into the stator 3 with high precision.

[0018] Furthermore, because no force acts in a direction perpendicular to the insertion direction when the high-speed rotor 5 is inserted into the stator 3, there is no need to widen the gap between the high-speed rotor 5 and the stator 3 to improve the efficiency of the assembly work. If the gap between the high-speed rotor 5 and the stator 3 were widened, the output of the magnetic wave gear device would decrease. For this reason, in the magnetic wave gear device of this embodiment, it is possible to suppress the decrease in output caused by a widening of the gap between the high-speed rotor and the stator.

[0019] In this embodiment, the base of the magnet module is made of laminated electromagnetic steel sheets. If eddy current loss caused by harmonic magnetic flux is not an issue, the base of the magnet module may be an integrated magnetic material.

[0020] In this embodiment, the two rotor magnets 7, 8 are each composed of four magnet pieces divided into two in the rotational and axial directions. When the rotor magnets 7, 8 are divided into magnet pieces, eddy currents caused by harmonic magnetic flux are less likely to flow, and eddy current loss in the rotor magnets 7, 8 can be reduced. However, if eddy current loss in the rotor magnets is not an issue, the rotor magnets 7, 8 may each be composed of a single magnet.

[0021] Embodiment 2 In the first embodiment, a base made of multiple laminated electromagnetic steel plates is used as the base of the magnet module. In the second embodiment, a powdered magnetic material is used as the base of the magnet module. Other than that, the configuration of the magnet module is the same as that of the magnet module in the first embodiment. Furthermore, the configurations of the high-speed rotor and the magnetic wave gear device are also the same as those in the first embodiment.

[0022] As the powdered magnetic material, for example, a powdered material such as iron or an alloy of iron and nickel can be used.

[0023] In a high-speed rotor using a magnet module configured in this way, the boundary between the magnetic poles is at the center of the magnet module, and the base of the magnet module becomes the magnetic path between the magnetic poles, reducing the magnetic resistance between the magnetic poles and making it possible to suppress a decrease in the output of a magnetic wave gear device using this high-speed rotor.

[0024] In addition, since the base of the magnet module is made of powdered magnetic material, the current path is interrupted and eddy currents are less likely to flow, similar to embodiment 1. Therefore, in this magnet module, eddy current loss caused by harmonic magnetic flux can be reduced.

[0025] Although the present application describes various exemplary embodiments, the various features, aspects, and functions described in one or more embodiments are not limited to application to a particular embodiment, but may be applied to the embodiments alone or in various combinations. Therefore, countless modifications not exemplified are assumed within the scope of the technology disclosed in this application, including, for example, modifying, adding, or omitting at least one component, and further, extracting at least one component and combining it with a component of another embodiment. [Explanation of symbols]

[0026] 1 magnetic wave gear device, 2 frame, 3 stator, 4 low-speed rotor, 5 high-speed rotor, 6 base, 7, 8 rotor magnet, 31 stator core, 32 stator winding, 33 stator magnet, 41 rotating shaft, 42 low-speed rotor end plate, 42a spoke, 51 high-speed rotor core, 52, 52a, 52b, 52c magnet module, 61 electromagnetic steel plate, 62 bottom plate, 63 end plate, 64 fixing bolt.

Claims

1. A rotor in which magnet modules are arranged in a circular ring around a rotation axis, The magnet module has a base made of a magnetic material and two rotor magnets with different poles arranged on the outer peripheral surface of the base with a gap in the rotational direction of the rotation shaft, and the opposing rotor magnets of two adjacent magnet modules in the rotational direction have the same pole and are in close contact with each other.

2. 2. The rotor according to claim 1, wherein the base is made of electromagnetic steel plates laminated in the axial direction of the rotating shaft.

3. 2. The rotor according to claim 1, wherein the base is made of a powdered magnetic material.

4. a stator having a stator core with a plurality of slots in a circumferential direction, a stator winding and a stator magnet disposed in the slots; A first rotor is disposed on an inner circumferential side of the stator with a gap therebetween; a second rotor that is concentric with a rotation axis of the first rotor and that is disposed on an inner peripheral side of the first rotor via a gap, A magnetic wave gear device, wherein the second rotor is configured as the rotor according to any one of claims 1 to 3.

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