Dual rotor motor

Abstract

To provide a dual rotor motor that uses a distributed winding system to improve torque efficiency compared to conventional motors.SOLUTION: A dual rotor motor includes a stator, an outer rotor, and an inner rotor. The stator has a plurality of outer slots, a plurality of outer stator teeth, a plurality of inner slots, a plurality of inner stator teeth, and winding coils. When a first condition is that the circumferential length of the outer stator teeth on which adjacent in-phase winding coils are wound is shorter than the circumferential length of the outer stator teeth on which adjacent out-of-phase winding coils are wound, and a second condition is that the circumferential length of the inner stator teeth on which adjacent in-phase winding coils are wound is shorter than the circumferential length of the inner stator teeth on which adjacent out-of-phase winding coils are wound, the dual rotor motor satisfies at least one of the first and second conditions.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 has a rotor on the inside and outside of a stator. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-98802 Summary of the Invention [Problem to be solved by the invention]

[0004] Conventional dual rotor motors generally use toroidal windings, which are concentrated windings, but if a dual rotor motor uses distributed windings, the rotating magnetic field generated by the stator can be made closer to a sine wave, which has the advantage of making it easier to control torque ripple.

[0005] An object of the present invention is to provide a dual rotor motor that employs a distributed winding system and can improve torque efficiency compared to conventional motors. [Means for solving the problem]

[0006] To achieve the above object, the present invention provides a dual-rotor motor comprising a stator, an outer rotor, and an inner rotor. The stator has a plurality of outer slots arranged in the circumferential direction, a plurality of outer stator teeth provided between each of the outer slots, a plurality of inner slots arranged radially inward of the outer slots and arranged in the circumferential direction, a plurality of inner stator teeth provided between each of the inner slots, and a winding coil having multiple phases wound around the plurality of outer stator teeth and the plurality of inner stator teeth. The outer rotor is arranged radially outward of the stator, has a plurality of first salient pole portions protruding radially inward, and is rotatable about the rotation axis. The inner rotor is arranged radially inward of the stator, has a plurality of second salient pole portions protruding radially outward, and is rotatable about the rotation axis. A dual-rotor motor satisfies at least one of the first and second conditions, where a first condition is that the circumferential length of one of the plurality of outer stator teeth on which adjacent in-phase winding coils are wound is shorter than the circumferential length of another of the plurality of outer stator teeth on which adjacent out-of-phase winding coils are wound, and a second condition is that the circumferential length of one of the plurality of inner stator teeth on which adjacent in-phase winding coils are wound is shorter than the circumferential length of another of the plurality of inner stator teeth on which adjacent out-of-phase winding coils are wound. [Effects of the Invention]

[0007] According to the present invention, the dual rotor motor employs a distributed winding system, which can improve torque efficiency compared to conventional motors. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram showing an example of the configuration of a dual-rotor motor according to one embodiment. [Figure 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. DETAILED DESCRIPTION OF THE INVENTION

[0009] [Embodiment] An embodiment of the dual-rotor motor 1 will be described in detail below with reference to the accompanying drawings. The configuration of the embodiment described below, as well as the actions and results (effects) brought about by said configuration, are merely examples and are not limited to the following description. Note that in this specification, ordinal numbers are used only to distinguish between parts and components, and do not indicate order or priority.

[0010] The following describes the outline and structure of a dual-rotor motor 1 according to this embodiment. Figure 1 is a diagram showing an example of the configuration of a dual-rotor motor 1 according to one embodiment. The dual-rotor motor 1 according to this embodiment is used, for example, as a power generation motor or a drive motor in a hybrid vehicle (HV) or an electric vehicle (EV).

[0011] Dual-rotor motor 1 is a motor driven by a three-phase (U-phase, V-phase, W-phase) sine wave with different phases. Dual-rotor motor 1 has an eight-pole configuration. As shown in FIG. 1, dual-rotor motor 1 includes stator 10, outer rotor 12, and inner rotor 13. Stator 10 has a plurality of outer slots 101, a plurality of inner slots 102, a plurality of outer stator teeth 104, a plurality of inner stator teeth 105, and winding coils 106.

[0012] The outer rotor 12 is provided radially outside the stator 10. The outer rotor 12 is rotatable about a rotation axis Ax1. The outer rotor 12 has a plurality of first salient pole portions 121. Each of the plurality of first salient pole portions 121 protrudes radially inward.

[0013] The inner rotor 13 is provided radially inside the stator 10. The inner rotor 13 is rotatable around a rotation axis Ax1. The inner rotor 13 has a plurality of second salient pole portions 131. Each of the plurality of second salient pole portions 131 protrudes radially outward. Hereinafter, unless otherwise specified, the axial direction, radial direction, and circumferential direction refer to the central axis direction of the stator 10, the radial direction of the stator 10, and the circumferential direction of the stator 10.

[0014] The stator 10 has a total of 96 slots in the circumferential direction, including outer slots 101 with 48 slots at 24 locations on the outside and inner slots 102 with 48 slots at 24 locations on the inside. Each of the multiple outer slots 101 and inner slots 102 shown in Fig. 1 refers to one slot out of the 24 slots on the inside and 24 slots on the outside, respectively.

[0015] The first slot 1011, the second slot 1012, and the third slot 1013 are aligned in the circumferential direction. Similarly, the first slot 1021, the second slot 1022, and the third slot 1023 are aligned in the circumferential direction. The first slot 1021 is provided radially inward of the first slot 1011. Similarly, the second slot 1022 is provided radially inward of the second slot 1012. The third slot 1023 is provided radially inward of the third slot 1013.

[0016] The winding coils 106 are wound around the plurality of outer stator teeth 104 and the plurality of inner stator teeth 105, and have a plurality of phases. More specifically, a coil U1 corresponding to the U phase is arranged in the first slots 1011 and 1021. A coil V1 corresponding to the V phase is arranged in the second slots 1012 and 1022. A coil W1 corresponding to the W phase is arranged in the third slots 1013 and 1023. That is, in the range corresponding to the space between adjacent first salient pole portions 121 in the circumferential direction, one winding coil 106 corresponding to each of the U phase, V phase, and W phase is arranged on the stator 10. The coils U1, V1, and W1 are connected to each other.

[0017] Each of the multiple outer slots 101 faces the outer rotor 12. Each of the multiple outer slots 101 opens to the outer peripheral surface of the stator 10. Each of the multiple inner slots 102 faces the inner rotor 13. Each of the multiple inner slots 102 opens to the inner peripheral surface of the stator 10.

[0018] In the following description, the range corresponding to the space between adjacent first salient pole portions 121 in the circumferential direction of the stator 10 is referred to as a node. The node also refers to the range corresponding to the space between adjacent second salient pole portions 131. That is, the number of nodes in this embodiment, which has an eight-pole configuration, ranges from one to eight.

[0019] The winding coils 106 are wound using a distributed winding method. The winding coils 106 are configured so that each node contains one of the U, V, and W phases. While Fig. 1 shows winding coils 106 corresponding to the U, V, and W phases arranged in sequence in the circumferential direction at one node, multiple winding coils 106 corresponding to the U, V, and W phases may be arranged at one node.

[0020] The winding coils 106 wound in the two slots that are symmetrical with respect to the rotation axis Ax1 face in the same axial direction. For example, the winding coil 106 fixed in the first slot 1011 and the winding coil 106 fixed in the first slot 1011a face in the depth direction in the axial direction.

[0021] Of the coils for the U, V, and W phases, the coils for the U phase U1, U2, U3, U4, U5, U6, U7, and U8 are marked with symbols for the sake of explanation, but the symbols for the V and W phases are omitted in FIG. 1 to make the diagram easier to read.

[0022] The multiple outer stator teeth 104 protrude radially outward from the annular portion of the stator 10. The multiple outer stator teeth 104 extend radially. The multiple outer stator teeth 104 are spaced apart in the circumferential direction. The inner peripheral surface of the first salient pole portion 121 and the outer peripheral surface of the outer stator tooth 104 face each other in the radial direction with a small gap interposed between them. The multiple outer stator teeth 104 are respectively provided between the multiple outer slots 101. That is, the outer slots 101 are provided between adjacent outer stator teeth 104 in the circumferential direction.

[0023] The multiple inner stator teeth 105 protrude radially inward from the annular portion of the stator 10. The multiple inner stator teeth 105 extend radially. The multiple inner stator teeth 105 are spaced apart in the circumferential direction. The outer peripheral surface of the second salient pole portion 131 and the inner peripheral surface of the inner stator tooth 105 face each other in the radial direction with a small gap between them. The multiple inner stator teeth 105 are provided between the multiple inner slots 102, respectively. That is, the inner slots 102 are provided between adjacent inner stator teeth 105 in the circumferential direction.

[0024] The length L1 of each of the multiple first salient pole portions 121 in the circumferential direction (the width of the end portion of the first salient pole portion 121 at the radially inner side) is approximately equal to the sum L2 of the circumferential length of the outer stator teeth 104 among the multiple outer stator teeth 104 on which adjacent winding coils 106 of the same phase are wound, the circumferential length of the outer stator teeth 104 among the multiple outer stator teeth 104 on which adjacent winding coils 106 of different phases are wound, and the length of the outer slot 101 in the circumferential direction.

[0025] The length L3 of each of the multiple second salient pole portions 131 in the circumferential direction (the width of the end portion of the second salient pole portion 131 at the radially inner side) is approximately equal to the sum length L4 of the circumferential length of the inner stator teeth 105 among the multiple inner stator teeth 105 on which adjacent winding coils 106 of the same phase are wound, the circumferential length of the inner stator teeth 105 among the multiple inner stator teeth 105 on which adjacent winding coils 106 of different phases are wound, and the length of the inner slot 102 in the circumferential direction.

[0026] The length L5 between each of the plurality of outer slots 101 and the plurality of inner slots 102 in the radial direction is the minimum length required to fix the winding coil 106 to the stator 10. The plurality of outer slots 101 and the plurality of inner slots 102 may be integrated with each other. When the outer slot 101 and the plurality of inner slots 102 are integrated with each other, the stator 10 has a structure in which the stator 10 is divided into multiple parts by the integrated outer slots 101 and the plurality of inner slots 102.

[0027] Of the multiple outer stator teeth 104, the circumferential length L6 of the outer stator teeth 104 around which adjacent in-phase winding coils 106 are wound is shorter than the circumferential length L7 of the outer stator teeth 104 around which adjacent out-of-phase winding coils 106 are wound (first condition). Length L6 is, for example, 2 mm. When length L6 is 2 mm, magnetic flux flows between outer rotor 12 and inner rotor 13 without rate limitation.

[0028] Furthermore, among the multiple inner stator teeth 105, the circumferential length L8 of the inner stator teeth 105 around which adjacent in-phase winding coils 106 are wound is shorter than the circumferential length L9 of the inner stator teeth 105 around which adjacent out-of-phase winding coils 106 are wound (second condition). Length L8 is, for example, 2 mm. When length L8 is 2 mm, magnetic flux flows between outer rotor 12 and inner rotor 13 without being rate-determined.

[0029] (flow of magnetic flux) Next, the flow of magnetic flux in the dual-rotor motor 1 will be described with reference to Figure 2. In this embodiment, the rotation direction of the outer rotor 12 and the inner rotor 13 is counterclockwise.

[0030] 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 sinusoidal wave current. A magnetic field 1000 indicated by dotted arrows in Fig. 2 schematically represents a continuous magnetic field formed by current drive via the stator 10 and the first salient pole portion 121 and second salient pole portion 131 facing the stator 10.

[0031] More specifically, magnetic field 1000 is formed continuously between outer rotor 12 and inner rotor 13, via one pair of opposing first salient pole portion 121 and second salient pole portion 131 and another pair of opposing first salient pole portion 121 and second salient pole portion 131 that are adjacent in the circumferential direction. As indicated by the dotted arrow, magnetic field 1000 extends radially within stator 10.

[0032] 2, the magnetic field formed at one node is indicated by a dotted arrow, but similarly at the other nodes, a continuous magnetic field 1000 is formed between outer rotor 12 and inner rotor 13, via one set of opposing first salient pole portion 121 and second salient pole portion 131 and another set of opposing first salient pole portion 121 and second salient pole portion 131 that are adjacent in the circumferential direction. In other words, the magnetic field inside outer rotor 12 and the magnetic field inside inner rotor 13 are connected, and one magnetic field is formed at each node.

[0033] Therefore, as shown in FIG. 2, inside the stator 10, the magnetic field 1000 is concentrated in the region where the first salient pole portion 121 and the second salient pole portion 131 face each other, and the magnetic flux lines are directed in the approximately radial direction.

[0034] 2, a magnetic field 1000 faces radially inward between the first salient pole portion 121a, between the second salient pole portion 131a and the first salient pole portion 121a, and at the second salient pole portion 131a. That is, magnetic flux flows radially inward through the outer stator teeth 104a and the inner stator teeth 105a located between the first salient pole portion 121a and the second salient pole portion 131a. Because the outer slots 101a, 101b and the inner slots 102a, 102b are air gaps, magnetic flux does not easily flow through them.

[0035] The radially inner length of the first salient pole portion 121a in the circumferential direction is approximately equal to the sum of the circumferential length of the outer stator tooth 104a around which an adjacent out-of-phase winding coil 106 is wound, the circumferential length of the outer stator tooth 104b around which an adjacent in-phase winding coil 106 is wound, and the circumferential length of the multiple outer slots 101a.

[0036] In this structure, the magnetic flux flowing through first salient pole portion 121a is prevented from flowing toward outer stator teeth 104b, which prevents the dual-rotor motor 1 from generating torque in the opposite direction to the rotational direction (counterclockwise) of outer rotor 12 and inner rotor 13, thereby improving torque efficiency.

[0037] Furthermore, length L3 is the minimum length required to secure winding coil 106 to stator 10. Therefore, magnetic flux flowing through outer stator tooth 104a is prevented from flowing between outer slot 101a and inner slot 102a, and between outer slot 101b and inner slot 102b. This allows magnetic flux flowing through first salient pole portion 121a to flow more efficiently to second salient pole portion 131a. Consequently, the dual-rotor motor 1 can improve torque efficiency.

[0038] In the above embodiment, the dual-rotor motor 1 includes a stator 10, an outer rotor 12, and an inner rotor 13. The stator 10 includes a plurality of outer slots 101 arranged in the circumferential direction, a plurality of outer stator teeth 104 provided between each of the outer slots 101, a plurality of inner slots 102 arranged radially inward of the outer slots 101 and arranged in the circumferential direction, a plurality of inner stator teeth 105 provided between each of the inner slots 102, and a winding coil 106 having multiple phases wound around the outer stator teeth 104 and the inner stator teeth 105. The outer rotor 12 is arranged radially outward of the stator 10 and has a plurality of first salient pole portions 121 protruding radially inward, and is rotatable about the rotation axis Ax. The inner rotor 13 is arranged radially inward of the stator 10 and has a plurality of second salient pole portions 131 protruding radially outward, and is rotatable about the rotation axis Ax. When the first condition is that the circumferential length L6 of the outer stator teeth 104 on which adjacent in-phase winding coils 106 are wound among the multiple outer stator teeth 104 is shorter than the circumferential length L7 of the outer stator teeth 104 on which adjacent out-of-phase winding coils 106 are wound among the multiple outer stator teeth 104, and the second condition is that the circumferential length L8 of the inner stator teeth 105 on which adjacent in-phase winding coils 106 are wound among the multiple inner stator teeth 105 is shorter than the circumferential length L9 of the inner stator teeth 105 on which adjacent out-of-phase winding coils 106 are wound among the multiple inner stator teeth 105, the dual-rotor motor 1 satisfies at least one of the first and second conditions.

[0039] In the above-described configuration, magnetic flux flowing from outer rotor 12 to inner rotor 13 flows without rate restriction inside stator 10. Therefore, dual-rotor motor 1 can efficiently convert torque generated in winding coils 106 into torque in outer rotor 12 and inner rotor 13, thereby improving torque efficiency.

[0040] In addition, in this embodiment, the length of each of the multiple first salient pole portions 121 in the circumferential direction is approximately equal to the sum of the circumferential length of the outer stator teeth 104 among the multiple outer stator teeth 104 on which adjacent winding coils 106 of the same phase are wound, the circumferential length of the outer stator teeth 104 among the multiple outer stator teeth 104 on which adjacent winding coils 106 of different phases are wound, and the circumferential length of the multiple outer slots 101.

[0041] In the above-described configuration, magnetic flux flowing from outer rotor 12 toward stator 10 is prevented from flowing in a direction that generates torque (from first salient pole portion 121a toward outer stator teeth 104b) opposite the direction of rotation of outer rotor 12. As a result, dual-rotor motor 1 can efficiently convert torque generated in winding coil 106 into rotational forces of outer rotor 12 and inner rotor 13, thereby improving torque efficiency.

[0042] In addition, in this embodiment, the length of each of the multiple second salient pole portions in the circumferential direction is approximately equal to the sum of the length in the circumferential direction of the inner stator teeth 105 on which adjacent winding coils 106 of the same phase are wound, the length in the circumferential direction of the inner stator teeth 105 on which adjacent winding coils 106 of different phases are wound, and the length in the circumferential direction of the multiple inner slots 102.

[0043] In the above-described configuration, magnetic flux flowing from stator 10 toward inner rotor 13 is prevented from flowing in a direction (from inner stator teeth 105b toward second salient pole portion 131a) that generates torque in the opposite direction to the direction of rotation of inner rotor 13. This allows dual-rotor motor 1 to efficiently convert torque generated in winding coils 106 into rotational forces of outer rotor 12 and inner rotor 13, thereby improving torque efficiency.

[0044] In this embodiment, the length between each of the outer slots 101 and the inner slots 102 in the radial direction is the minimum length required to fix the winding coil 106 to the stator 10.

[0045] In the above-described configuration, magnetic flux flowing inside stator 10 is prevented from flowing in the circumferential direction of stator 10 between outer slots 101 and inner slots 102. This allows dual-rotor motor 1 to efficiently allow magnetic flux to flow between outer rotor 12 and inner rotor 13, thereby improving torque efficiency.

[0046] Although the embodiments of the present invention have been described above, the above-described embodiments are presented as examples and are not intended to limit the scope of the present invention. This novel embodiment can be embodied in various other forms. Furthermore, various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. Furthermore, this embodiment is included within the scope and spirit of the invention, and is also included in the inventions and their equivalents described in the claims. [Explanation of symbols]

[0047] 1 Dual rotor motor 10 Stator 12 outer rotor 13 Inner rotor 101, 101a, 101b outer slots 102, 102a, 102b inner slots 104, 104a, 104b outer stator teeth 105, 105a, 105b Inner stator teeth 106 Winding coil 121, 121a 1st salient pole part 131, 131a 2nd salient pole part 1000 magnetic field Ax1 Rotation axis L1: The length of each of the plurality of first salient pole portions in the circumferential direction L2 is the sum of the length of the outer stator teeth on which adjacent in-phase winding coils are wound, the length of the outer stator teeth on which adjacent out-of-phase winding coils are wound, and the length of the outer slot in the circumferential direction. L3: The length between each of the outer slots and the inner slots in the radial direction L4: The length of each of the plurality of second salient pole portions in the circumferential direction L5: The sum of the length of the inner stator teeth on which adjacent in-phase winding coils are wound, the length of the inner stator teeth on which adjacent out-of-phase winding coils are wound, and the length of the inner slot in the circumferential direction. L6: Length of outer stator teeth on which adjacent in-phase winding coils are wound L7: Length of outer stator teeth on which adjacent out-of-phase winding coils are wound L8: Length of the inner stator teeth on which adjacent in-phase winding coils are wound L9: Length of the inner stator teeth on which adjacent out-of-phase winding coils are wound U1, U2, U3, U4, U5, U6, U7, U8 Coils corresponding to U phase V1 Coil corresponding to V phase W1 Coil corresponding to W phase

Claims

1. a plurality of circumferentially arranged outer slots; a plurality of outer stator teeth respectively provided between the plurality of outer slots; a plurality of inner slots arranged radially inside the plurality of outer slots and aligned in a circumferential direction; a plurality of inner stator teeth respectively provided between the plurality of inner slots; a stator including a winding coil having a plurality of phases wound around the plurality of outer stator teeth and the plurality of inner stator teeth; an outer rotor provided radially outward of the stator, the outer rotor having a plurality of first salient pole portions protruding radially inward, and the outer rotor rotatable about a rotation axis; an inner rotor provided radially inside the stator, the inner rotor having a plurality of second salient pole portions protruding radially outward, and the inner rotor rotatable about the rotation shaft; Equipped with a first condition is that the circumferential length of the outer stator teeth on which the adjacent winding coils of the same phase are wound is shorter than the circumferential length of the outer stator teeth on which the adjacent winding coils of the different phase are wound, When the second condition is that the circumferential length of the inner stator tooth on which the adjacent winding coil of the same phase is wound is shorter than the circumferential length of the inner stator tooth on which the adjacent winding coil of the different phase is wound, At least one of the first condition and the second condition is satisfied. Dual rotor motor.

2. The length of each of the plurality of first salient pole portions in the circumferential direction is the circumferential length of the outer stator teeth on which the adjacent winding coils of the same phase are wound, among the plurality of outer stator teeth; and the length in the circumferential direction of the outer stator teeth, on which the adjacent winding coils of different phases are wound, is approximately equal to the sum of the lengths of the outer slots in the circumferential direction, The dual rotor motor of claim 1 .

3. The length of each of the plurality of second salient pole portions in the circumferential direction is the circumferential length of the inner stator teeth on which the adjacent inner stator teeth of the same phase are wound; and the length in the circumferential direction of the inner stator teeth, on which the adjacent winding coils of different phases are wound, is approximately equal to the sum of the lengths of the inner slots in the circumferential direction, and 3. The dual-rotor motor according to claim 1 or 2.

4. a length between each of the outer slots and the inner slots in the radial direction is a minimum length required to fix the winding coil to the stator; 3. The dual-rotor motor according to claim 1 or 2.

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