Stator, motor and unmanned aerial vehicle

Abstract

A stator according to one embodiment of the present invention is a stator for a multiphase motor, and is provided with a lead-out section comprising one or a plurality of adjacent slots. The windings are divided into phase windings corresponding to each of the plurality of phases. Each of the phase windings includes: a plurality of winding portions wound around the teeth; the lapping wire is used for connecting the winding parts; and a start end portion and a terminal end portion from which both ends of the phase winding are led out. The start end portion and the terminal end portion of each phase winding are led out from any one of the slots of the lead-out portion. At least one of the phase windings includes: a first winding portion wound around the teeth on one side in the circumferential direction than the lead-out portion; a second winding portion wound around the teeth on the other side in the circumferential direction than the lead-out portion; and a first lap line that connects the first winding portion and the second winding portion on one side of the lead-out portion in the axial direction, and at least a portion of the first lap line is disposed on the one side of the lead-out portion in the axial direction on the outside of at least a portion of the starting end portion and the ending end portion of each phase winding in the radial direction.

Description

Technical Field

[0001] The invention relates to a stator, a motor and an unmanned aerial vehicle. Background Art

[0002] A conventional stator is disclosed in Patent Document 1. The stator is a stator of a multi-phase motor in which windings are wound on a stator core, and comprises: an annular core back; a plurality of teeth extending radially from the core back and arranged circumferentially; and slots formed between adjacent teeth, and the windings are divided into phase windings corresponding to each of the multi-phases. Prior art literature Patent Literature

[0003] Patent Document 1: Japanese Patent Application Publication No. 2000-188839 Summary of the invention

[0004] In the stator disclosed in the above patent document, when the starting end and the terminal end of each phase winding are collectively led out, for example, from adjacent slots, in order to improve assemblability, there is a concern that the lap wires connecting the winding parts and the lead wires leading out the starting end and the terminal end may become longer, especially in the last wound phase winding. When the lap wires or the lead wires are long, it is difficult to arrange them, so not only the workability is deteriorated, but also the proportion of the winding part in the slot, that is, the space factor, may be reduced.

[0005] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to facilitate the arrangement of the jumper wires and the lead wires, improve the workability of stator manufacturing, and improve the space factor.

[0006] A stator according to one aspect of the present invention is a stator of a multi-phase motor, and is provided with a lead-out portion consisting of one or a plurality of adjacent slots. The winding is divided into phase windings corresponding to each of the multi-phases, and the phase windings respectively include: a plurality of winding portions wound on the teeth; a lap wire connecting the winding portions; and a starting end portion and a terminal portion where both ends of the phase winding are not led out, and the starting end portion and the terminal portion of each phase winding are led out from any slot of the lead-out portion. At least one of the phase windings includes: a first winding portion wound on a tooth on one circumferential side of the lead-out portion; a second winding portion wound on a tooth on the other circumferential side of the lead-out portion; and a first lap wire connecting the first winding portion and the second winding portion on one axial side of the lead-out portion, and at least a portion of the first lap wire is arranged radially outside at least a portion of the starting end portion and the terminal portion of each phase winding on the axial side of the lead-out portion.

[0007] According to the present invention, it is possible to facilitate the arrangement of the jumper wires and the lead wires, improve the workability of stator manufacturing, and improve the space factor. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 11 is an explanatory diagram showing a winding pattern of a stator winding according to a first embodiment of the present invention ( Figure 2 ) is an explanatory diagram showing the display of teeth and grooves. Figure 2 It is an explanatory diagram showing a winding pattern of a stator winding according to the first embodiment of the present invention. DETAILED DESCRIPTION

[0009] Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings. In addition, in this specification, the direction parallel to the central axis of the motor is referred to as the "axial direction", the direction orthogonal to the central axis of the motor is referred to as the "radial direction", and the direction along the arc centered on the central axis of the motor is referred to as the "circumferential direction". In the drawings, the same reference numerals are given to the same or corresponding parts, and the description thereof will not be repeated.

[0010] The drone has a propeller and a motor, and the motor rotates the propeller around a central axis. The motor has a rotor and a stator, and the rotor has a shaft, a rotor holder, and a rotor magnet. The shaft is columnar and forms a rotation axis extending along the central axis, and is supported by a bearing so as to be able to rotate around the central axis. The rotor holder is fixed to the shaft and is in the shape of a covered cylinder. The rotor magnet is fixed to the inner circumferential surface of the rotor holder and is arranged opposite to the radial outer side of the stator. When the motor is driven, torque is generated between the stator and the rotor magnet. In addition, the rotor holder may also have a cover-shaped hub fixed to the shaft and a cylindrical back iron extending axially at the radial outer edge of the hub. In addition, the motor is an outer rotor type motor.

[0011] The stator and the rotor are arranged opposite to each other in the radial direction. The stator is a stator of a multi-phase motor in which a winding is wound on a stator core, and comprises: an annular core back; a plurality of teeth T extending radially from the core back and arranged circumferentially; and slots S formed between adjacent teeth T.

[0012] The core back is formed in an annular shape around the central axis and is composed of laminated steel plates. The teeth T extend radially outward from the core back and are arranged at equal intervals in the circumferential direction. Thus, a stator for an outer rotor type motor is formed.

[0013] The winding is divided into phase windings corresponding to each phase of the multi-phase motor, and each phase winding includes: a plurality of winding portions wound on the teeth T; a lap wire connecting the winding portions; and a starting end portion and a terminal end portion leading out the two ends of the phase winding.

[0014] In the winding portion, the phase winding is wound around the tooth T for multiple turns, and the boundary between the winding portion and the overlapped line is as follows. In the first turn of the phase winding wound around the tooth T, the overlapped line is formed until the portion of the phase winding extending axially from the slot S, and the portion after the phase winding is arranged in the slot S is the winding portion. In addition, in the last turn of the phase winding wound around the tooth T, the winding portion is formed until the portion of the phase winding arranged in the slot S, and the overlapped line is formed after the portion of the phase winding extending axially from the slot S. In other words, the boundary between the winding portion and the overlapped line is defined by the axial end face of the stator core. Here, it is interpreted that there is no overlapped line between the winding portions of the phase winding wound continuously around the adjacent teeth T.

[0015] The stator further includes a lead-out portion L consisting of one or a plurality of adjacent slots S, and the starting end and the terminal end of each phase winding are led out from one of the slots S of the lead-out portion L. Each phase winding includes a lead-out wire connecting the winding portion and the starting end, and a lead-out wire connecting the winding portion and the terminal end.

[0016] The boundary between the winding portion and the lead wire is as follows. In the first turn of the phase winding wound on the tooth T, the portion of the phase winding extending axially from the slot S is the lead wire, and the portion of the phase winding arranged in the slot S is the winding portion. In addition, in the last turn of the phase winding wound on the tooth T, the portion of the phase winding arranged in the slot S is the winding portion, and the portion of the phase winding extending axially from the slot S is the lead wire. In other words, the boundary between the winding portion and the lead wire is defined by the axial end face of the stator core.

[0017] The overlapping wires and the lead wires are arranged to prevent looseness by appropriately combining the overlapping wires and the lead wires extending circumferentially on one axial side of the stator core, extending axially in the slot S, and extending circumferentially on the other axial side of the stator core. When the overlapping wires and the lead wires extend axially in the slot S many times, the overlapping wires and the lead wires become longer, so the workability of stator manufacturing deteriorates, and the ratio of the winding portion in the slot S, that is, the space factor, deteriorates.

[0018] The lead portion L is composed of one or a plurality of adjacent slots S, which can gather the windings drawn from the stator. Therefore, the windings drawn from the stator or the wires connected to the windings drawn from the stator are connected to other parts such as the substrate, which is simple to lead, and the workability is improved. For example, in a drone, an arm-like portion extends from the main body portion, and a propeller and a motor driving the propeller are arranged at the front end of the arm-like portion, but by gathering the windings drawn from the stator or the wires connected to the windings drawn from the stator, it is easy to build the wiring into the arm-like portion.

[0019] On the other hand, when the lead portion L is composed of one or a plurality of adjacent slots S and the starting and terminal portions of each phase winding are gathered and led out, the circumferential width of the overlapping wire or the lead wire extending in the circumferential direction becomes larger, and the number of times the overlapping wire or the lead wire extends in the axial direction in the slot S increases, and the overlapping wire or the lead wire may become longer. In particular, in the last wound phase winding, when the overlapping wire or the lead wire is long, the arrangement of the overlapping wire or the lead wire becomes difficult.

[0020] The following will describe an exemplary first embodiment of the present invention having a stator of a three-phase motor having phases U, V, and W. The winding is divided into a first phase winding corresponding to U, a second phase winding corresponding to V, and a third phase winding corresponding to W. However, the motor is not limited to three phases, and may be multi-phase other than three phases.

[0021] Figure 1 1 is an explanatory diagram showing a winding pattern of a stator winding according to a first embodiment of the present invention ( Figure 2 ) is an explanatory diagram showing the display of the tooth T and the slot S, Figure 2 It is an explanatory diagram showing a winding pattern of a stator winding according to the first embodiment of the present invention. Figure 1 and Figure 2 The diagram shows the state where the teeth T1 to T12 arranged in parallel in the circumferential direction are unfolded into a straight line and viewed from the radially outer side in the direction of the center axis. Slots S1 to S12 formed by spaces are formed between adjacent teeth T1 to T12. For example, slot S1 is formed between teeth T1 and T2, and slot S2 is formed between teeth T2 and T3. The same is true for the subsequent teeth T and slot S. Slot S12 is formed between tooth T12 and tooth T1. In addition, Figure 1 In the diagram, slots S1 to S12 are represented by rectangles with symbols, and teeth T1 to T2 are represented by the sides of the rectangles with symbols. Figure 2 In the figure, for the purpose of simplification, rectangles with numbers corresponding to the symbols of the slots S1 to S12 are shown for the purpose of indicating the positions of the slots S and the teeth T, and the symbols of the teeth T are omitted.

[0022] Each phase winding is led out from the lead-out portion L to one axial side of the stator core ( Figure 1 , Figure 2 In addition, for each tooth T, when viewed from the radially outer side, CW (clockwise) indicates that the phase winding is wound clockwise, and CCW (counterclockwise) indicates that it is wound counterclockwise.

[0023] The lead-out portion L is composed of three adjacent slots, namely slot S8, slot S9 and slot S10. The beginning of the first phase winding is led out from slot S10, and the end of the first phase winding is led out from slot S9. The beginning of the second phase winding is led out from slot S9, and the end of the second phase winding is led out from slot S8. The beginning of the third phase winding is led out from slot S8, and the end of the third phase winding is led out from slot S10. Here, the positions of the winding start and the winding end of each phase can also be swapped, in other words, the beginning and the end can also be swapped.

[0024] In the first embodiment, the lead portion L is composed of a plurality of adjacent slots S, and the phase winding is led out from all the slots S of the lead portion L. However, the lead portion L may be composed of one slot S, or may include a slot S from which the phase winding is not led out between the slots S from which the phase winding is led out.

[0025] In the first embodiment, the stator is a stator of a three-phase motor in which three phase windings are connected by a delta connection, and the lead portion L is composed of three adjacent slots S. The third phase winding includes: a first winding portion C1, which is wound on a tooth T on one circumferential side of the lead portion L; a second winding portion, which is wound on a tooth T on the other circumferential side of the lead portion L; and a first lap wire, which connects the first winding portion C1 and the second winding portion C2 on one axial side of the lead portion L. In addition, the third phase winding also includes: a winding portion wound on a tooth T adjacent to the tooth T on which the first winding portion C1 is wound; and a winding portion wound on a tooth T adjacent to the tooth T on which the second winding portion C2 is wound. In this way, for the third phase winding, the circumferential width of the winding portion and the lead portion L can be reduced, and the lead wire of the third phase winding can be shortened.

[0026] The starting end and the terminal end of the third phase winding are led out one by one from one of the two slots S on both sides of the lead-out portion L in the circumferential direction. The starting end and the terminal end of the first phase winding are led out one by one from one of the two slots S on the other side of the lead-out portion L in the circumferential direction, and the starting end and the terminal end of the second phase winding are led out one by one from one of the two slots S on one side of the lead-out portion L in the circumferential direction. In this way, delta connection becomes easy.

[0027] The starting end of the first phase winding corresponding to U is led out from slot S10 to one axial side of the stator core, and the lead wire extends axially in slot S10, and extends circumferentially from slot S10 to slot S12 on the other axial side of the stator core. The lead wire extends axially in slot S12, and extends circumferentially from slot S12 to slot S1 on one axial side of the stator core, and is connected to the winding portion of the first phase winding wound on tooth T2. After the winding portion is formed by winding the first phase winding on tooth T2 with Z turns CW (clockwise), the winding portion is then formed by winding the first phase winding on tooth T3 with Z turns CCW (counterclockwise). Here, Z turns refers to the number of turns of the winding portion, and the number of turns Z is a specified natural number. The lap wire led out from slot S2 extends circumferentially to slot S4 on one axial side of the stator core. The lap wire extends axially in slots S4, S5, and S6, extends circumferentially from slot S5 to slot S6 on one axial side of the stator core, and extends circumferentially from slot S4 to slot S5 and from slot S6 to slot S7 on the other axial side of the stator core, and is connected to the winding portion of the first phase winding wound on tooth T8. After the winding portion is formed by winding the first phase winding on tooth T8 with Z turns CCW (counterclockwise), the winding portion is then formed by winding the first phase winding on tooth T9 with Z turns CW (clockwise). The terminal end of the first phase winding is led out from slot S9 to one axial side of the stator core.

[0028] The starting end of the second phase winding corresponding to V is led out from slot S9 to one axial side of the stator core. After the second phase winding is wound on tooth T10 with Z turns CW (clockwise) to form a winding portion, the second phase winding is then wound on tooth T11 with Z turns CCW (counterclockwise) to form a winding portion. The lap wire led out from slot S10 extends circumferentially to slot S12 on one axial side of the stator core. The lap wire extends axially in slot S12, slot S1, and slot S2, circumferentially from slot S1 to slot S2 on one axial side of the stator core, and circumferentially from slot S12 to slot S1 and from slot S2 to slot S3 on the other axial side of the stator core, and is connected to the winding portion of the second phase winding wound on tooth T4. After the winding portion is formed by winding the second phase winding on tooth T4 with Z turns CCW (counterclockwise), the winding portion is then formed by winding the second phase winding on tooth T5 with Z turns CW (clockwise). The lead wire led out from slot S4 extends circumferentially to slot S6 on the other axial side of the stator core. The lead wire extends axially in slots S6, S7, and S8, circumferentially from slot S6 to slot S7 on one axial side of the stator core, and circumferentially from slot S7 to slot S8 on the other axial side of the stator core. The terminal end of the second phase winding is led out from slot S8 to one axial side of the stator core.

[0029] The starting end of the third phase winding corresponding to W is led out from slot S8 to one axial side of the stator core. The lead wire extends axially in slot S8, extends circumferentially from slot S8 to slot S6 on the other axial side of the stator core, and is connected to the winding portion of the third phase winding wound on tooth T7. After the winding portion is formed by winding the third phase winding on tooth T7 with Z turns CCW (counterclockwise), the winding portion is then formed by winding the third phase winding on tooth T6 with Z turns CW (clockwise). The lap wire led out from slot S6 extends circumferentially to slot S12 on one axial side of the stator core, and is connected to the winding portion of the third phase winding wound on tooth T12. After the winding portion is formed by winding the third phase winding on tooth T12 with Z turns CCW (counterclockwise), the winding portion is then formed by winding the third phase winding on tooth T1 with Z turns CW (clockwise). The lead wire led out from slot S12 extends circumferentially to slot S10 on the other axial side of the stator core and extends axially in slot S10. The terminal end of the third phase winding is led out from slot S10 to one axial side of the stator core.

[0030] Here, the third phase winding wound last includes: a first winding portion C1 wound on the tooth T6 on one circumferential side of the slots S8, S9, and S10 as the lead-out portion L; and a second winding portion C2 wound on the tooth T12 on the other circumferential side of the lead-out portion L. In addition, it includes a first lap wire B that extends circumferentially from the slot S6 to the slot S12 on the axial side of the stator core and connects the first winding portion C1 and the second winding portion C2. Here, the first lap wire B does not extend axially in the slot S, in other words, does not include a portion arranged on the other side of the stator core, and extends circumferentially from the slot S6 to the slot S12 on the axial side of the stator core.

[0031] According to the above, the overlapping wires and the lead wires can be shortened in the third phase winding. As a result, the overlapping wires and the lead wires can be easily arranged, the workability of stator manufacturing can be improved, and the proportion of the winding portion in the slot S, that is, the space factor can be improved.

[0032] Here, at least a portion of the first overlap wire B is arranged radially outside at least a portion of the starting end portion and the terminal end portion of each of the first phase winding, the second phase winding and the third phase winding on the axial side of the lead-out portion L. Thus, it is possible to prevent the first overlap wire B from being located radially inside when it extends circumferentially from the slot S6 to the slot S12 on the axial side of the stator core. At this time, on the radial inside of the core back, the portion of the steel plate of the core back that is exposed in the axial direction, i.e., the exposed portion, can be ensured, and by pressing the exposed portion of the core back during assembly, the stator core can be pressed into other components with high dimensional accuracy. In addition, on the axial side of the stator core, it is possible to prevent the first overlap wire B from being located radially inside of the insulating member arranged on the tooth, with the result that poor withstand voltage can be prevented.

[0033] As a more preferred embodiment, all of the starting end portions and the terminal ends of the first phase winding, the second phase winding, and the third phase winding are led out from the slot S of the lead-out portion L on the radially inner side of the first overlap wire B. Thus, it is possible to more reliably prevent the first overlap wire B from being located radially inner when extending circumferentially from the slot S6 to the slot S12 on one axial side of the stator core.

[0034] In the above description, the case of a motor having 12 slots S is described, but in the case of a motor having N slots S, the slot S to which the first overlap wire B connects with the second winding portion C2 is the Mth slot S from the slot S to which the first winding portion C1 connects with the first overlap wire B toward the other side in the circumferential direction, and M is greater than or equal to N / 2. For example, in the case of a motor having 24 slots S, the slot S to which the first overlap wire B connects with the second winding portion C2 is the 12th slot S from the slot S to which the first winding portion C1 connects with the first overlap wire B toward the other side in the circumferential direction. As in the case of the above case of 12 slots S, in the case of 24 slots S, the first overlap wire B is also arranged on one side of the axial direction of the stator core in half a circumference, and therefore, the overlap wire of the phase winding including the first overlap wire B can be shortened.

[0035] The motor may include the stator of the first embodiment, and may also include a rotor that is radially opposite to the stator and rotates around the central axis. In this case, the workability of manufacturing the motor can be improved, and the power consumption of the motor can be reduced. A drone may include such a motor, and may also include a propeller fixed to the rotor so as to rotate around the central axis. In this case, the workability of manufacturing the drone can be improved, and the power consumption of the drone can be reduced.

[0036] The exemplary embodiments of the present invention are described above with reference to the accompanying drawings. However, the above-mentioned embodiments are merely examples of the present invention, and the present invention is not limited to the above-mentioned embodiments, and can be implemented in various ways without departing from the scope of its main purpose. For ease of understanding, the accompanying drawings are schematically shown with each component as the main body, and the thickness, length, number, etc. of each component shown in the drawings are different from the actual ones due to the convenience of making the drawings. In addition, the material, shape, size, etc. of each component shown in the above-mentioned embodiment is an example, and there is no special limitation, and various changes can be made within the scope that does not substantially depart from the effect of the present invention. In addition, within the scope of the technical idea of ​​the present invention, the structure of the embodiment can be appropriately changed. In addition, the embodiments can also be implemented in combination within the possible scope.

[0037] Note that the present technology can also adopt the following configurations.

[0038] (1) A stator is a stator of a multi-phase motor having windings wound on a stator core, comprising: an annular core back; a plurality of teeth extending radially from the core back and arranged circumferentially; slots formed between adjacent teeth; and a lead-out portion consisting of one or a plurality of adjacent slots, wherein the winding is divided into phase windings corresponding to each of the multi-phases, and the phase windings respectively include: a plurality of windings wound on the teeth; a lap wire connecting the windings; and a starting end portion and a terminal end portion leading out of both ends of the phase windings, wherein each of the phase windings has a plurality of windings wound on the teeth; a lap wire connecting the windings; and a starting end portion and a terminal end portion leading out of both ends of the phase windings, wherein each of the phase windings has a plurality of windings wound on the teeth; a lap wire connecting the windings; and a starting end portion and a terminal end portion leading out of both ends of the phase windings. The starting end portion and the terminal portion are led out from any one of the slots of the lead-out portion, and at least one of the phase windings includes: a first winding portion wound on the tooth on one circumferential side of the lead-out portion; a second winding portion wound on the tooth on the other circumferential side of the lead-out portion; and a first lap wire connecting the first winding portion and the second winding portion on one axial side of the lead-out portion, at least a portion of the first lap wire being arranged radially outside at least a portion of the starting end portion and the terminal portion of each phase winding on the axial side of the lead-out portion. (2) The stator according to (1), wherein the starting end portion and the terminal end portion of each of the phase windings are all led out radially inward of the first overlapping line. (3) A stator according to (1) or (2), comprising N slots, wherein the slot connecting the first lap line and the second winding portion is the Mth slot from the slot connecting the first winding portion and the first lap line toward the other side in the circumferential direction, and M is greater than N / 2. (4) The stator according to any one of (1) to (3) is a stator of a three-phase motor in which the phase windings are connected by a delta connection, the windings are divided into a first phase winding, a second phase winding and a third phase winding corresponding to each of the three phases, the lead-out portion is composed of three adjacent slots, the starting end and the terminal end of the first phase winding are led out from any one of the two slots on one circumferential side of the lead-out portion, the starting end and the terminal end of the second phase winding are led out from any one of the two slots on the other circumferential side of the lead-out portion, the third phase winding includes the first lap wire, and the starting end and the terminal end of the third phase winding are led out from any one of the two slots on both circumferential sides of the lead-out portion. (5) A motor comprising: the stator according to any one of (1) to (4); and a rotor that faces the stator in a radial direction and rotates around a central axis. (6) An unmanned aerial vehicle comprising: the motor described in (5); and a propeller fixed to the rotor and rotating around a central axis.

[0039] The present invention can be used in, for example, motors for drones. Explanation of symbols

[0040] T…tooth T1~T12…tooth S...Slot S1~S12…Slot L…Leading part C1…First winding section C2…Second winding section B…the first lap line.

Claims

1. A stator, which is a stator of a polyphase motor having a winding wound around a stator core, characterized in that: have: Ring-shaped core back; A plurality of teeth extending radially from the back of the core and arranged circumferentially; grooves formed between adjacent teeth; as well as A lead-out portion consisting of one or a plurality of adjacent grooves, The winding is divided into phase windings corresponding to each of the multiple phases, The phase windings respectively include: a plurality of winding portions wound around the teeth; The overlapping wires connecting the winding parts; and Lead out the starting end and the terminal end of the two ends of the phase winding, The starting end portion and the terminal end portion of each phase winding are led out from any one of the slots of the lead-out portion, At least one of the phase windings comprises: a first winding portion wound around the tooth on one side of the lead-out portion in the circumferential direction; a second winding portion wound around the tooth on the other side of the lead-out portion in the circumferential direction; and A first lap wire connecting the first winding portion and the second winding portion on one axial side of the lead-out portion, At least a portion of the first overlapping wire is arranged radially outside at least a portion of the starting end portion and the terminal end portion of each of the phase windings on one side of the lead portion in the axial direction.

2. The stator according to claim 1, characterized in that: The starting end portion and the terminal end portion of each of the phase windings are all led out radially inward of the first overlapping line.

3. The stator according to claim 1, characterized in that: With N slots, The groove where the first overlap line connects the second winding portion is the Mth groove from the groove where the first winding portion connects the first overlap line toward the other side in the circumferential direction, and M is greater than or equal to N / 2.

4. The stator according to claim 1, characterized in that: The stator is a stator of a three-phase motor in which the phase windings are connected by delta connection, The winding is divided into a first phase winding, a second phase winding and a third phase winding corresponding to each of the three phases, The lead-out portion is composed of three adjacent grooves. The starting end portion and the terminal end portion of the first phase winding are led out from any one of two slots on one side in the circumferential direction of the lead-out portion. The starting end portion and the terminal end portion of the second phase winding are led out from any one of the two slots on the other side in the circumferential direction of the lead-out portion. The third phase winding includes the first bonding wire, The starting end portion and the terminal end portion of the third phase winding are led out from any one of two slots on both sides in the circumferential direction of the lead-out portion.

5. A motor, characterized in that: have: The stator according to any one of claims 1 to 4; and The rotor is opposite to the stator in the radial direction and rotates around the central axis.

6. A drone, characterized in that: have: The motor according to claim 5; and A propeller is fixed to the rotor and rotates around a central axis.

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