Dual rotor motor

Abstract

To provide a dual rotor motor capable of improving maximum torque without depending on a permanent magnet.SOLUTION: A dual rotor motor includes: a stator having a winding coil; an inner rotor which is rotatably arranged on an inner peripheral side of the stator with a rotation axis as a center; and an outer rotor which is rotatably arranged on an outer peripheral side of the stator with the rotation axis as the center. The winding coil of the stator forms a magnetic field which makes a magnetic flux flowing through the inner rotor and a magnetic flux flowing through the outer rotor to be a series in a radial direction of the rotation axis in the stator.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a dual rotor motor. [Background technology]

[0002] One type of motor is called a dual rotor motor, which generates torque by configuring two rotors around one stator. A dual rotor motor is a motor that has a stator, an inner rotor that is arranged rotatably around a rotation axis on the inner periphery of the stator, and an outer rotor that is arranged rotatably around a rotation axis on the outer periphery of the stator.

[0003] Patent Document 1 discloses a dual rotor motor having a stator with windings wound around a stator core, an inner rotor arranged on the inner circumference of the stator so as to be freely rotatable around a rotating shaft, and an outer rotor arranged on the outer circumference of the stator so as to be freely rotatable around a rotating shaft. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2011-188605 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, conventional dual rotor motors generally use a toroidal winding method, and in order to improve the maximum torque of a conventional dual rotor motor, it is necessary to place permanent magnets in the dual rotor motor, which makes the dual rotor motor expensive.

[0006] An object of the present invention is to provide a dual-rotor motor that can improve maximum torque without relying on permanent magnets. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, a dual-rotor motor of one embodiment of the present invention comprises a stator having a winding coil, an inner rotor arranged on the inner side of the stator so as to be rotatable around a rotation axis, and an outer rotor arranged on the outer side of the stator so as to be rotatable around the rotation axis, wherein the winding coil of the stator forms a magnetic field that connects the magnetic flux flowing in the inner rotor and the magnetic flux flowing in the outer rotor in the radial direction of the rotation axis within the stator.

[0008] A dual-rotor motor according to another aspect of the present invention comprises a stator having a winding coil, an inner rotor arranged on the inner peripheral side of the stator so as to be rotatable about a rotating shaft, and an outer rotor arranged on the outer peripheral side of the stator so as to be rotatable about the rotating shaft, wherein in the stator, the winding coil is full-pitch wound, and when the salient pole portions of the inner rotor and the salient pole portions of the outer rotor are arranged so as to be aligned in a straight line in the radial direction of the rotating shaft, at least one coil corresponding to three phases is arranged in sequence in the circumferential direction of the rotating shaft between adjacent salient pole portions of the inner rotor and between adjacent salient pole portions of the outer rotor. Effect of the Invention

[0009] According to the present invention, the maximum torque can be improved without relying on permanent magnets. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram illustrating an example of a configuration of a dual rotor motor according to an embodiment. [Diagram 2] FIG. 2 is a diagram showing an example of magnetic flux distribution when the dual rotor motor shown in FIG. 1 is driven by a three-phase sine wave current. [Diagram 3] FIG. 3 is an explanatory diagram of a dual rotor motor that employs a toroidal winding system. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] A dual rotor motor according to an embodiment of the present invention will be described in detail below with reference to the accompanying drawings. The dual rotor motor according to an embodiment of the present invention is used, for example, as a generator motor or drive motor for a hybrid electric vehicle or a battery electric vehicle. Note that the present invention is not limited to the following embodiment, and the components in the following embodiment include those that can be easily conceived by a person skilled in the art, those that are substantially the same, and those that are within the so-called equivalent range. Furthermore, various omissions, substitutions, modifications, and combinations of the components can be made without departing from the spirit of the following embodiment.

[0012] <Embodiment> FIG. 1 is a diagram showing an example of the configuration of a dual rotor motor according to an embodiment. The dual rotor motor 1 of the example shown in FIG. 1 has a stator 10, an outer rotor 11 arranged rotatably around a rotation axis Z on the outer periphery side of the stator 10, and an inner rotor 12 arranged rotatably around the rotation axis Z on the inner periphery side of the stator 10. The stator 10 has a winding coil. In the following, the circumferential direction refers to the direction corresponding to the circumferential direction of the rotation axis Z. The radial direction refers to the radial direction centered on the rotation axis Z. In the following, the thickness direction of the stator 10 refers to the radial direction centered on the rotation axis Z.

[0013] The dual-rotor motor 1 of the example shown in Fig. 1 has an eight-pole configuration, with the outer rotor 11 having eight salient pole portions (hereinafter referred to as outer salient pole portions) 111, and the inner rotor 12 also having eight salient pole portions (hereinafter referred to as inner salient pole portions) 121. Fig. 1 shows an arrangement in which the outer salient pole portions 11 and the inner salient pole portions 121 are both aligned in a straight line in the radial direction of the rotation axis Z. There is a small air gap between the stator 10 and each of the opposing outer salient pole portions 111. There is also a small air gap between the stator 10 and each of the opposing inner salient pole portions 121.

[0014] The dual rotor motor 1 shown in Fig. 1 is a motor driven by a three-phase (U-phase, V-phase, W-phase) sine wave with different phases. The stator 10 has a total of 96 slots, including 48 slots at 24 locations on the inside and 48 slots at 24 locations on the outside, in the circumferential direction of the stator 10. Slot 13 shown in Fig. 1 refers to one of the 24 slots on each of the inside and outside.

[0015] Here, the winding method for the stator 10 is distributed winding and full pitch winding, and each node is always configured to have one U-phase, one V-phase, and one W-phase. In one example, one coil corresponding to each of the U-phase, V-phase, and W-phase is arranged in sequence in the circumferential direction at one node, but a plurality of coils corresponding to each of the U-phase, V-phase, and W-phase may be arranged at one node. The coils are mutually connected. The node refers to the inner salient pole portions 121 adjacent to each other in the circumferential direction. The node also refers to the outer salient pole portions 111 adjacent to each other in the circumferential direction. In other words, in an eight-pole configuration, there are nodes 1 to 8.

[0016] 1, such as coil U1 corresponding to the U phase, coil V1 corresponding to the V phase, and coil W1 corresponding to the W phase, one each of the coils corresponding to the U phase, V phase, and W phase are arranged in a range corresponding to adjacent inner salient pole portions 121 in the circumferential direction of stator 10. Similarly, one each of the coils corresponding to the U phase, V phase, and W phase are arranged in a range corresponding to adjacent outer salient pole portions 111 of each of the other nodes.

[0017] Furthermore, the coils at each node are of the same phase and orientation as the node located 180° (deg) in the circumferential direction of stator 10. Coils marked with an "x" symbol in Fig. 1, for example coil 131, are coils oriented from the front side to the back side of stator 10 shown in Fig. 1. Coils marked with a "circle dot" symbol in Fig. 1, for example coil 132, are coils oriented from the back side to the front side of stator 10 shown in Fig. 1. Of the U-phase, V-phase, and W-phase coils, symbols are attached to V-phase coils V1, V2, ... V8 for the sake of explanation, but symbols are omitted for U-phase and W-phase coils to make the diagram easier to read.

[0018] Fig. 2 is a diagram showing an example of magnetic flux distribution when the dual rotor motor 1 shown in Fig. 1 is driven by a three-phase sine wave current. The dotted arrow 1000 in Fig. 2 shows a schematic representation of a continuous magnetic field formed by current drive through the outer salient pole portion 111 and the inner salient pole portion 121 facing the stator 10.

[0019] Specifically, the magnetic field is formed continuously between the outer rotor 11 and the inner rotor 12 via one opposing pair of the outer salient pole portion 111 and the inner salient pole portion 121 and another opposing pair of the outer salient pole portion 111 and the inner salient pole portion 121 that are adjacent to each other in the circumferential direction. As indicated by dotted arrow 1000, the magnetic field is formed within the stator 10 in the radial direction of the stator 10.

[0020] 2, the magnetic field formed at one node is indicated by a dotted arrow 1000, but similarly at the other nodes, a continuous magnetic field is formed between the outer rotor 11 and the inner rotor 12 via one opposing pair of outer salient pole portion 111 and inner salient pole portion 121 and one opposing pair of outer salient pole portion 111 and inner salient pole portion 121 that are adjacent in the circumferential direction. In other words, the magnetic fields of the outer rotor 11 and inner rotor 12 are connected, and one magnetic field is formed for each node.

[0021] A magnetic field as indicated by the dotted arrows 1000 is formed at each node in the circumferential direction of the stator, resulting in a magnetic flux distribution with magnetic flux lines that span the outer rotor 11 and the inner rotor 12, via one opposing pair of outer salient pole portion 111 and inner salient pole portion 121 and one opposing pair of outer salient pole portion 111 and inner salient pole portion 121 that are adjacent to each other in the circumferential direction.

[0022] 2, magnetic flux lines are concentrated in the region where the outer salient pole portion 111 and the inner salient pole portion 121 face each other in the stator 10, and these magnetic flux lines are oriented in the thickness direction. Magnetic flux lines are unlikely to be formed in the circumferential direction in the stator 10.

[0023] (Explanation of the first effect) Fig. 3 is an explanatory diagram of a dual rotor motor that employs a toroidal winding system. Fig. 3 shows an example of the configuration and magnetic flux distribution of a dual rotor motor that employs a toroidal winding system.

[0024] The dual rotor motor shown in FIG. 3 has a stator 20, an outer rotor 21 arranged on the outer periphery of the stator 20 so as to be rotatable about a rotation axis, and an inner rotor 22 arranged on the inner periphery of the stator 20 so as to be rotatable about a rotation axis.

[0025] The dual rotor motor shown in FIG. 3 employs a toroidal winding method, but the other components are similar to those of the dual rotor motor 1 shown in FIG. 1, so a detailed description of the components shown in FIG. 3 will be omitted.

[0026] The dual rotor motor shown in FIG. 3 forms different, independent opposing magnetic fields between the outer rotor 21 on the outer periphery of the stator 20 and the inner rotor 22 on the inner periphery of the stator 20, as shown by the dotted arrow 2001 and the dotted arrow 2002.

[0027] In the example shown in FIG. 3, magnetic field 1 indicated by dotted arrow 2001 causes magnetic flux lines between the outer rotor 21 and stator 20 to be oriented counterclockwise, and magnetic field 2 indicated by dotted arrow 2002 causes magnetic flux lines between the inner rotor 22 and stator 20 to be oriented clockwise.

[0028] 3, on the left side of one slot 23 out of one of the slots, magnetic field 1 indicated by dotted arrow 2001 causes magnetic flux lines to flow from outer rotor 21 into stator 20 via outer salient pole portion 211. Magnetic field 2 indicated by dotted arrow 2002 causes magnetic flux lines to flow from inner rotor 22 into stator 20 via inner salient pole portion 221. In other words, within stator 20, magnetic flux lines repel each other on the outer rotor 21 side and the inner rotor 22 side, and each magnetic flux line is oriented in the circumferential direction of stator 20 within stator 20, forming a magnetic path that passes through the iron core in stator 20 in the circumferential direction of stator 20.

[0029] 3, the magnetic flux lines extending from the outer rotor 21 side in the circumferential direction inside the stator 20 change direction to the outer rotor 21 side at the outer salient pole portion 211 located second in the circumferential direction of the stator 20. In addition, the magnetic flux lines extending from the inner rotor 22 in the circumferential direction inside the stator 20 change direction to the inner rotor 22 side at the inner salient pole portion 221 located second in the circumferential direction of the stator 20.

[0030] In this way, a dual rotor motor using the toroidal winding method creates different magnetic fields between the outer rotor 21 on the outer periphery of the stator 20 and the inner rotor 22 on the inner periphery of the stator 20. In the case of the toroidal winding method, rotating magnetic fields are generated on the outside and inside by each magnetic field, so if the reluctance method is used as is, the inductance difference cannot be increased and an improvement in maximum torque cannot be expected. Therefore, the toroidal winding method is expensive because it requires the placement of permanent magnets to improve torque.

[0031] In contrast, in the dual-rotor motor according to the embodiment, a continuous magnetic flux line is formed across the outer rotor 11 and the inner rotor 12. Therefore, one magnetic circuit is formed via the air gaps in the outer salient pole portion 111 facing the stator 10 and the inner salient pole portion 121 facing the stator 10, respectively, and a larger inductance difference can be obtained. In addition, in one example, adjacent salient poles also contribute to torque generation, and all salient poles can be used for torque generation.

[0032] Therefore, with the dual rotor motor configuration according to the embodiment, it is possible to improve the maximum torque without relying on permanent magnets. Since the maximum torque can be improved without using permanent magnets, it is also possible to reduce costs.

[0033] (Explanation of the second effect) As shown in Figures 2 and 3, the thicknesses of the stator 10 of the dual rotor motor 1 and the stator 20 of the dual rotor motor using the toroidal winding method are such that d1 < d2, and it is possible to make the thickness of the stator 10 of the dual rotor motor 1 thinner than the stator 20 of the dual rotor motor using the toroidal winding method.

[0034] 3, magnetic flux lines flowing from outer rotor 21 into stator 20 via outer salient pole portion 211 are oriented in the circumferential direction of stator 20 within stator 20, and have a magnetic path passing through the iron core in stator 20 in the circumferential direction of stator 20. In addition, magnetic flux lines flowing from inner rotor 22 into stator 20 via inner salient pole portion 221 are also oriented in the circumferential direction of stator 20 within stator 20, and have a magnetic path passing through the iron core in stator 20 in the circumferential direction of stator 20.

[0035] For this reason, the magnetic flux passing through a portion 201 in the stator 20 called a yoke in the circumferential direction increases, so that the magnetic path at the portion 201 needs to be thick enough to prevent magnetic flux saturation.

[0036] 2, in the dual rotor motor 1, a continuous magnetic flux line spans the outer rotor 11 and the inner rotor 12 via the outer salient pole portion 111 and the inner salient pole portion 121 facing the outer salient pole portion 111. That is, in the stator 10, at a position corresponding to the inner salient pole portion 121, a magnetic path faces in the thickness direction of the stator 10, and therefore there are few magnetic paths of magnetic lines of force facing in the circumferential direction of the stator 10. For this reason, the thickness d1 of the stator 10 can be formed thinner than that of a dual rotor motor that employs a toroidal winding method.

[0037] In the description of the dual rotor motor according to the embodiment, a configuration in which the full pitch winding and the UVW phases always occur once in one node has been used as an example that is highly effective in improving maximum torque, but this is just one example.

[0038] Also, the motor driven by a three-phase (U-phase, V-phase, W-phase) sine wave has been described as an example, but this is an example of a polyphase AC method. [Explanation of symbols]

[0039] 1 Dual rotor motor 10 Stator 11 Outer rotor 12 Inner rotor 13 Slots 111 Outer salient pole part 121 Inner salient pole part 1000 Magnetic Field d1 Thickness U1 Coil corresponding to U phase V1 Coil corresponding to V phase W1 Coil corresponding to W phase

Claims

1. a stator having a winding coil; an inner rotor arranged on an inner circumferential side of the stator so as to be rotatable about a rotation axis; an outer rotor disposed on an outer circumferential side of the stator so as to be rotatable about the rotation shaft; Equipped with The winding coil of the stator forms a magnetic field that connects the magnetic flux flowing through the inner rotor and the magnetic flux flowing through the outer rotor in a radial direction of the rotation shaft within the stator. Dual rotor motor.

2. a stator having a winding coil; an inner rotor arranged on an inner circumferential side of the stator so as to be rotatable about a rotation axis; an outer rotor disposed on an outer circumferential side of the stator so as to be rotatable about the rotation shaft; Equipped with In the stator, The winding coil is a full-pitch winding, when the salient pole portions of the inner rotor and the salient pole portions of the outer rotor are arranged so as to be aligned in a radial direction of the rotating shaft, at least one coil corresponding to three phases is arranged in sequence between adjacent salient pole portions of the inner rotor and between adjacent salient pole portions of the outer rotor in a circumferential direction of the rotating shaft. Dual rotor motor.

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