Motor

Abstract

To provide a motor in which a plurality of magnets is arranged in good balance against an inner side surface of a yoke while improving an assemblability of each magnet to the yoke.SOLUTION: A motor (1) of the present invention, comprises: a rotor (15); and a stator (13) arranged so as to be opposite to the rotor (15). The rotor (15) includes: a yoke (151); and a plurality of magnets (153). The yoke (151) includes a first projection part (201) and a second projection part (202) which are projected to each magnet. The first projection part (201) is arranged on one side in a rotational axis (X) direction of the rotor (15) against the second projection part (202). The second projection part (202) is larger than the size of the first projection part (201) to a peripheral direction.SELECTED DRAWING: Figure 7

Description

[Technical field]

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

[0002] Conventionally, in motors used in multicopters such as drones, a structure has been known in which the yoke of the rotor has a circular cylindrical yoke portion and a number of yoke protrusions that protrude radially inward from the inner surface of the cylindrical yoke portion, with magnets disposed between each of the multiple yoke protrusions (see, for example, Patent Document 1).

[0003] In the motor of Patent Document 1, the distance between the magnets is equal to the circumferential length of the multiple yoke protrusions, which leads to an increase in size, and there is a demand to shorten the distance between the magnets in order to reduce the size. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2019-68604 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the motor of Patent Document 1, if one were to remove the yoke protrusions formed on the inside surface of the yoke and arrange multiple magnets without any gaps, there was a risk that the last magnet would not fit in and it would be impossible to install if the multiple magnets were manufactured with a positive dimensional tolerance, for example. On the other hand, if the multiple magnets were manufactured with a negative dimensional tolerance, there was a risk that the gaps between the magnets would become too large.

[0006] The present invention has been made in view of the above background, and has as its object to improve the ease of assembling a magnet to a yoke. [Means for solving the problem]

[0007] The above problems are solved by the present invention as described below. That is, a motor of the present invention includes a rotor and a stator disposed opposite the rotor, the rotor includes a yoke and a plurality of magnets, the yoke includes a first protruding portion and a second protruding portion protruding toward the magnets, the first protruding portion is disposed on one side of the second protruding portion in a direction of a rotation axis of the rotor, and the second protruding portion is larger in size in the circumferential direction than the first protruding portion. [Brief description of the drawings]

[0008] [Figure 1] 1 is a perspective view showing an overall configuration of an outer rotor type motor according to an embodiment of the present invention; [Diagram 2] 1 is a cross-sectional perspective view of a motor according to an embodiment of the present invention; [Diagram 3] 1 is a perspective view showing an overall configuration of a stator core according to an embodiment of the present invention; [Figure 4] 1 is a perspective view showing a yoke and a magnet of a motor according to an embodiment of the present invention; [Diagram 5] FIG. 2 is a plan view showing a configuration of a magnet according to an embodiment of the present invention. [Figure 6] FIG. 2 is a perspective view showing a configuration of a yoke of a motor according to an embodiment of the present invention. [Figure 7] 3 is a perspective view showing the configuration of a first protrusion and a second protrusion formed on an inner surface of a yoke of a motor according to one embodiment of the present invention. FIG. [Figure 8] 1 is a plan view showing a configuration of a special jig used when assembling a magnet of a motor according to an embodiment of the present invention to a yoke. [Figure 9] 1A shows the configuration of a receiving jig used when inserting a yoke into a magnet of a motor according to an embodiment of the present invention, and FIG. 1B shows a cross-sectional view illustrating an assembly procedure. [Figure 10]1 is a perspective view showing a state in which a yoke is inserted into a magnet attached to a dedicated jig according to an embodiment of the present invention; FIG. [Figure 11] 1A is a perspective view showing the arrangement of magnets relative to a yoke according to an embodiment of the present invention, FIG. 1B is a partially enlarged perspective view, and FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Overview of the embodiment First, a typical embodiment of the invention disclosed in this application will be outlined. In the following description, as an example, reference numerals in the drawings corresponding to components of the invention are given in parentheses.

[0010] [1] A motor (1) according to a representative embodiment of the present invention comprises a rotor (15) and a stator (13) arranged opposite the rotor (15). The rotor (15) has a yoke (151) and a plurality of magnets (153). The yoke (151) has a first protrusion (201) protruding toward the magnet (153) and a second protrusion (202). The first protrusion (201) is arranged on one side of the second protrusion (202) in the direction of the rotation axis (X) of the rotor (15). The second protrusion (202) is larger in size in the circumferential direction than the first protrusion (201).

[0011] [2] A plurality of second protrusions (202) are provided in the circumferential direction of the yoke (151), and the magnets (153) are disposed between adjacent second protrusions (202).

[0012] [3] The number of the second protrusions (202) is equal to the number of the magnets (153).

[0013] [4] The outer circumferential surfaces of the first protrusion (201) and the second protrusion (202) have an arc shape.

[0014] [5] The multiple magnets (153) are in contact with each other in the circumferential direction.

[0015] Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing the overall configuration of an outer rotor type motor according to an embodiment of the present invention. FIG. 2 is a cross-sectional perspective view of a motor according to an embodiment of the present invention. FIG. 3 is a cross-sectional view showing the overall configuration of a stator core according to an embodiment of the present invention. FIG. 4 is a perspective view showing a yoke and a magnet of a motor according to an embodiment of the present invention. FIG. 5 is a plan view showing the configuration of a magnet according to an embodiment of the present invention. FIG. 6 is a perspective view showing the configuration of a yoke of a motor according to an embodiment of the present invention. FIG. 7 is a perspective view showing the configuration of a first protruding portion and a second protruding portion formed on the inner surface of a yoke of a motor according to an embodiment of the present invention. FIG. 8 is a plan view showing the configuration of a dedicated jig used when assembling a magnet of a motor according to an embodiment of the present invention to a yoke. FIG. 9 is a cross-sectional view (A) of a receiving jig used when inserting a yoke of a motor according to an embodiment of the present invention into a magnet, and (B) for explaining an assembling procedure. FIG. 10 is a perspective view showing a state in which a yoke is inserted into a magnet attached to a dedicated jig according to an embodiment of the present invention. FIG. 11 is a perspective view (A), a partially enlarged perspective view (B), and a top view (C) showing the arrangement of magnets with respect to a yoke according to one embodiment of the present invention.

[0016] In the following description of this embodiment, for convenience, the direction in which the axis X extends when the motor 1 rotates is referred to as the rotation axis X direction or the axis X direction. In the following description, for convenience, the direction of the arrow a in the rotation axis X direction is referred to as the upper side, and the direction of the arrow b is referred to as the lower side. In addition, in the radial direction perpendicular to the axis X, the direction of the arrow c away from the axis X is referred to as the outer periphery side, and the direction of the arrow d approaching the axis X is referred to as the inner periphery side. In the following description, the upper side (the direction of the arrow a) and the lower side (the direction of the arrow b) refer to the up-down relationship of the motor 1, and do not necessarily coincide with the up-down relationship in the direction of gravity. Furthermore, in Figs. 1 to 3, the direction of the arrow e is referred to as the clockwise direction centered on the axis X, and the direction of the arrow f is referred to as the counterclockwise direction.

[0017] As shown in FIGS. 1 to 3, the motor 1 is an outer rotor type brushless motor mounted on a floating mobile body such as a drone (not shown).

[0018] 1, for example, a drone's propeller (not shown) is attached to the upper side (arrow a direction) of the motor 1, and the drone's body is attached to the lower side (arrow b direction) of the motor 1. As shown in FIG. 2, the motor 1 mainly has a stator housing 11, a stator 13, a rotor 15, a holder 17, and a bearing 19.

[0019] The stator housing 11 has a cylindrical inner peripheral portion 111, a cylindrical outer peripheral portion 112, and a connecting portion 115. The inner peripheral portion 111 of the stator housing 11 is formed in a cylindrical or approximately cylindrical shape extending in the direction of the rotation axis X. The inner peripheral portion 111 holds a bearing 19 on its surface (hereinafter referred to as the "inner peripheral surface") on the inner peripheral side (direction of the arrow d).

[0020] Specifically, the inner circumferential portion 111 holds a bearing 19a on the upper side in the direction of the rotation axis X (the direction of the arrow a), and holds a bearing 19b on the lower side (the direction of the arrow b).

[0021] That is, the inner periphery 111 of the stator housing 11 functions as a bearing holder for the bearings 19a, 19b. The bearings 19a, 19b are, for example, ball bearings. However, the bearings are not limited to this, and various other bearings such as sleeve bearings may be used.

[0022] The outer circumferential portion 112 of the stator housing 11 is formed in a cylindrical or substantially cylindrical shape extending in the direction of the rotation axis X, similar to the inner circumferential portion 111. Both the inner circumferential portion 111 and the outer circumferential portion 112 are centered on the axis X.

[0023] A connecting portion 115 is provided between the inner peripheral portion 111 and the outer peripheral portion 112 of the stator housing 11, and the inner peripheral portion 111 and the outer peripheral portion 112 are integrally formed with the connecting portion 115. The connecting portion 115 connects the inner peripheral portion 111 and the outer peripheral portion 112 to each other. The connecting portion 115 extends from the outer peripheral end of the inner peripheral portion 111 further toward the outer peripheral side (in the direction of arrow c) and is connected to the inner peripheral end of the outer peripheral portion 112.

[0024] A stator core 131 of the stator 13 is fixed to a surface on the outer periphery side of the outer periphery portion 112 (hereinafter referred to as the “outer periphery surface”). The stator 13 includes the stator core 131, an insulator 135, and a coil 139.

[0025] 3, stator core 131 is a laminate of silicon steel plates or the like, and is composed of an annular portion 132 and teeth portions 133 which are a plurality of magnetic pole portions extending from annular portion 132 toward the outer periphery (in the direction of arrow d).

[0026] Insulators 135 made of an insulating material are attached to teeth 133 of stator core 131. Coils 139 (FIG. 2) are wound around teeth 133 via insulators 135. Teeth 133 and coils 139 of stator core 131 are electrically insulated from each other via insulators 135.

[0027] The rotor 15 (FIG. 2) has a yoke 151 and a magnet 153. The yoke 151 is an annular, cylindrical iron core extending in the direction of the rotation axis X. The yoke 151 is fixed integrally with the magnet 153 while surrounding the magnet 153. The yoke 151 is made of a magnetic material such as iron.

[0028] As shown in FIG. 4, a plurality of magnets 153 are fixed in close contact with an inner surface 151n of a yoke 151 (hereinafter, referred to as an "inner surface") by an adhesive or the like.

[0029] As shown in Fig. 5, the magnet 153 has a tile shape that is curved convexly toward the outer periphery. All the magnets 153 have the same shape and structure. The magnets 153 are anisotropic magnets oriented by molding in a magnetic field. However, the magnets are not limited to this and may be isotropic magnets.

[0030] The magnet 153 is formed in a tile shape that is curved generally convexly toward the outer periphery in accordance with the inner diameter of the inner side surface 151n of the yoke 151, and is therefore fixed in a state in which the outer periphery surface 153out of the magnet 153 is in close contact with the inner side surface 151n of the yoke 151. At this time, the magnet 153 shown in Fig. 5 and the magnet 153 having the polarity reversed from that of the magnet 153 shown in Fig. 5 are arranged alternately.

[0031] The height of magnet 153 in the direction of rotation axis X is greater than the height of yoke 151 in the direction of rotation axis X. However, this is not limited thereto, and yoke 151 may be greater than magnet 153, or may be the same height.

[0032] As shown in Figures 6 and 7, the yoke 151 has a first protrusion 201 that protrudes in an arc shape from the inner surface 151n on the lower side in the axis X direction (in the direction of arrow b) toward the rotation axis X in the radial direction, i.e., toward the magnet 153 (Figure 3).

[0033] The first protrusions 201 are provided on the lower side in the axis X direction (the direction of the arrow b) of the inner surface 151n of the yoke 151, and are arranged at equal intervals along the circumferential direction (28 in this case). However, the present invention is not limited to this, and the number of the first protrusions 201 may be any number as long as it is equal to or less than the number of the magnets 153.

[0034] The plurality of first protrusions 201 have a distance between circumferential ends of adjacent first protrusions 201 that is slightly longer than the length L1 of magnet 153. That is, the plurality of first protrusions 201 are provided along the inner surface 151n of yoke 151 in a state in which magnet 153 can be disposed between adjacent first protrusions 201. This first protrusion 201 serves as a guide and positioning when magnet 153 is attached to inner surface 151n of yoke 151.

[0035] In addition, the yoke 151 has a second protrusion 202 that protrudes in an arc shape from the inner surface 151n on the upper side in the axis X direction (in the direction of arrow a) toward the rotation axis X in the radial direction, i.e., toward the magnet 153.

[0036] The second protrusions 202 are provided on the upper side of the inner surface 151n of the yoke 151 in the axis X direction (direction of the arrow a) and at equal intervals along the circumferential direction (28 in this case). However, the number is not limited to this and may be any number as long as it is equal to or less than the number of the magnets 153 and is the same as the number of the first protrusions 201. Incidentally, the first protrusions 201 and the second protrusions 202 are formed by driving a pin into the outer surface of the yoke 151 in a mold.

[0037] The second protruding portion 202 has a circular arc shape that is larger in the circumferential direction than the first protruding portion 201. Specifically, the length of the circular arc in the radial cross-sectional shape of the second protruding portion 202 is longer than the circular arc in the radial cross-sectional shape of the first protruding portion 201, and the amount of protrusion of the second protruding portion 202 in the radial direction is larger than the amount of protrusion of the first protruding portion 201 in the radial direction.

[0038] Furthermore, the first protruding portion 201 and the second protruding portion 202 do not have to be arc-shaped, and may be, for example, an elliptical arc shape, a rectangular cross section, a triangular cross section, or various other shapes. For example, the first protruding portion 201 may be arc-shaped, and the second protruding portion 202 may be rectangular in cross section, and any combination of shapes, sizes, protruding amounts, etc. is also possible.

[0039] With respect to the multiple second protrusions 202, the distance between the circumferential ends of adjacent second protrusions 202 is set to the same distance as the length L1 of the magnet 153. That is, the second protrusions 202 are larger in the circumferential direction than the first protrusions 201, and the distance between the circumferential ends of the second protrusions 202 is shorter than the distance between the circumferential ends of the first protrusions 201. Therefore, the second protrusions 202 play a role in preventing the circumferential position of the magnet 153 from being shifted in a state in which the magnet 153 is assembled to the inner surface 151n of the yoke 151.

[0040] The centers of the second protrusions 202 and the first protrusions 201 are arranged parallel to each other and in a straight line along the axis X. In this case, the second protrusions 202 and the first protrusions 201 are arranged in a total of 28 rows as a vertical row of protrusions along the axis X.

[0041] That is, the first protrusions 201 and the second protrusions 202 are arranged in a row on the upper and lower sides in the direction of the axis X on the inner surface 151n of the yoke 151, and a total of 28 rows of protrusions are arranged in the circumferential direction. A magnet 153 is arranged between one row of the first protrusions 201 and the second protrusions 202 and an adjacent row of the first protrusions 201 and the second protrusions 202.

[0042] Holder 17 (FIGS. 1 and 2) is made of an aluminum alloy and has an overall disk shape. However, this is not limited to this, and holder 17 may be made of other materials such as resin or plastic. Holder 17 is also formed by cutting out. However, this is not limited to this, and holder 17 may be formed by press molding or the like.

[0043] The holder 17 has an inner circumferential portion 171 provided on the inner circumferential side (in the direction of the arrow c), an outer circumferential end portion 173 provided at the end on the outer circumferential side (in the direction of the arrow d), and spokes 175 .

[0044] The inner circumferential portion 171 of the holder 17 has a cylindrical protrusion 171d provided with a through hole 171h centered on the axis X, and a flange portion 171f extending radially from an end portion on the outer circumferential side of the protrusion 171d. The flange portion 171f has a size capable of covering the inner circumferential portion 111 of the stator housing 11 from above (the direction of the arrow a).

[0045] The protruding portion 171d of the inner peripheral portion 171 has a cylindrical inner cylinder portion 172 extending in the up-down direction (the direction of the arrow ab) centered on the axis X. The inner rings of the bearings 19a and 19b are held on the outer circumferential surface of the inner cylinder portion 172 of the inner peripheral portion 171. That is, the inner cylinder portion 172 of the holder 17 functions as the center of rotation of the motor 1.

[0046] A plurality of (e.g., six) spokes 175 are connected to the end of the flange portion 171f on the outer circumferential side (in the direction of arrow c), and the annular outer circumferential end portion 173 is connected to the radial tip portions of the spokes 175. That is, the spokes 175 connect the flange portion 171f of the inner circumferential portion 171 and the outer circumferential end portion 173.

[0047] Next, a procedure for assembling and fixing the magnet 153 to the yoke 151 will be described. As shown in Figures 8(A) to (D), first, a jig 500 is prepared. The jig 500 is made of a magnetic material such as iron, and is configured with a plurality of pieces 501 (28 pieces in this case) that can be connected to each other.

[0048] That is, the jig 500 can be formed in a straight line by connecting each piece 501 as shown in FIG. 8(A), or can be formed in a circular shape by connecting all the pieces 501 as shown in FIG. 8(B).

[0049] 8(C) and (D), outer peripheral surface 501g of piece 501 has the same radius of curvature as inner peripheral surface 153in of magnet 153, and inner peripheral surface 153in of magnet 153 can be in close contact with outer peripheral surface 501g of piece 501. All pieces 501 have the same shape and structure.

[0050] The piece 501 has a semicircular first engagement portion 501a with a circular through hole 501ah formed at one end side in the longitudinal direction, and an elliptical second engagement portion 501b with an elliptical through hole 501bh formed at the other end side in the longitudinal direction.

[0051] Adjacent pieces 501 are connected in a rotatable state by a pin (not shown) through holes 501ah and 501bh, with the first engagement portion 501a of one piece 501 and the second engagement portion 501b of the other piece 501 overlapping each other.

[0052] Piece 501 has a length in the longitudinal direction that is the same as length L1 of magnet 153. Piece 501 is a magnetic body, and magnet 153 is an anisotropic magnet, so that each magnet 153 is attached to each piece 501 in a one-to-one relationship by magnetic force.

[0053] With such jig 500 deployed in a linear fashion (FIG. 8(A)), magnets 153 are attached to the pieces 501, and the multiple magnets 153 are generally arranged in a linear fashion. Then, the piece 501 on one end of the jig 500 is connected to the piece 501 on the other end, whereby the jig 500 and the multiple magnets 153 are deployed in a circular fashion (FIG. 8(B)).

[0054] At this time, in the jig 500, the adjacent pieces 501 rotate slightly around a pin (not shown) as a fulcrum to form a circle. Therefore, the left side surface 153l and the right side surface 153r of the adjacent magnets 153 are slightly spaced apart on the radially outer periphery side, and a predetermined gap SP (FIG. 8(D)) is generated between the magnets 153.

[0055] However, since each piece 501 of the jig 500 remains in contact with each other even when expanded into a circular shape as a whole, the magnets 153 remain in contact with each other at the radially inner portion CP of the magnets 153.

[0056] 9(A) and (B), a cylindrical mounting jig 700 is prepared. The mounting jig 700 has a structure in which a large diameter cylindrical portion 701 and a small diameter cylindrical portion 702 having a smaller diameter than the large diameter cylindrical portion 701 are integrated via a step surface 703.

[0057] A circular recessed space 704 with a rectangular cross section is formed on the outer peripheral surface 702g of the small diameter cylindrical portion 702 of the receiving jig 700. This recessed space 704 is a space having a height and depth large enough to completely accommodate the piece 501 of the jig 500, but is too small to accommodate the magnet 153.

[0058] Using jig 500 with multiple magnets 153 attached to piece 501, piece 501 is fitted into recessed space 704 of small diameter cylindrical portion 702 of receiving jig 700 while being formed into a circular shape, so that the lower end face of magnet 153 abuts against step face 703 of large diameter cylindrical portion 701. In this state, inner surface 151n of yoke 151 is fitted along outer circumferential surface 153out of magnet 153 from the upper side (direction of arrow b) toward the lower side (direction of arrow a).

[0059] At this time, the yoke 151 can be fitted from the upper side (direction of arrow b) to the lower side (direction of arrow a) so that the first protrusion 201 enters the gap SP between the magnets 153 as a guide. In the process, since the second protrusion 202 exists above the first protrusion 201, the second protrusion 202 also enters the gap SP between the magnets 153. At this time, since the first protrusion 201 is smaller than the second protrusion 202, the yoke 151 can be inserted into the magnets 153 more easily.

[0060] In this case, the second protrusion 202 also plays a role in determining the circumferential position of the magnet 153. For example, in the case where the magnets 153 are formed with a negative intersection, if all the magnets 153 are arranged on the inner surface 151n of the yoke 151, there is a possibility that adjacent magnets 153 may not contact each other at certain portions.

[0061] However, since the distance between adjacent second protrusions 202 is equal to the length L1 of the magnets 153, all of the magnets 153 are accurately positioned so as to be point symmetric with respect to each other, and the inner circumferential portions CP of all of the magnets 153 are maintained in contact with each other.

[0062] At this time, the magnet 153 is attached to the inner surface 151n of the yoke 151 by magnetic force and adhesive, so that the positions of the magnet 153 and the yoke 151 in the up-down direction in the direction of the axis X and the circumferential direction of the inner surface 151n of the yoke 151 are maintained. In particular, the second protruding portion 202 suppresses the magnet 153 from shifting in the circumferential direction.

[0063] As a result, the jig 500, magnet 153, and yoke 151 are integrated together as shown in Fig. 10. Note that the receiving jig 700 is omitted in Fig. 10. After that, only the magnet 153 and yoke 151 are removed from the receiving jig 700, and the yoke 151 is fixed to the outer circumferential end 173 of the holder 17. In this way, the motor 1 is completed.

[0064] As shown in Figures 11(A) to (C), magnets 153 are attached to the inner surface 151n of yoke 151. Each magnet 153 is disposed between a plurality of rows of protrusions (first protrusions 201 and second protrusions 202) provided circumferentially on the inner surface 151n of yoke 151, so that the second protrusions 202 prevent magnets 153 from shifting out of position in the circumferential direction.

[0065] That is, the multiple magnets 153 are arranged in a well-balanced manner in point symmetry with respect to the inner surface 151n of the yoke 151 about the rotation axis X, and this state is maintained by the presence of the second protrusion 202. This allows the motor 1 to smoothly rotate the rotor 15.

[0066] According to the above configuration, the first protrusion 201 is formed on the inner surface 151n of the yoke 151 on the lower side in the axis X direction (direction of arrow b), and the second protrusion 202 is formed on the upper side (direction of arrow a), so that a total of 28 rows of the first protrusions 201 and the second protrusions 202 are provided in a row in the circumferential direction. This allows the motor 1 to easily and evenly arrange the magnets 153 between the same number of protrusion rows (the first protrusions 201 and the second protrusions 202).

[0067] In particular, when the magnets 153 are attached in a circular shape to the jig 500, gaps SP are created between the magnets 153, and therefore the yoke 151 can be easily assembled by simply inserting the first protrusion 201, which acts as a guide, from the outside so that it fits into the gaps SP.

[0068] In a state where the magnets 153 are arranged on the inner surface 151n of the yoke 151, the second protruding parts 202 larger than the first protruding parts 201 are also present between the magnets 153, and therefore the magnets 153 are fixed by an adhesive or the like while being prevented from shifting in the circumferential direction by the second protruding parts 202. In other words, the multiple magnets 153 are arranged in a well-balanced manner in point symmetry with respect to the inner surface 151n of the yoke 151, with the rotation axis X as the center.

[0069] Since the motor 1 is used in a drone or the like, which is a structure that rotates multiple propellers, it is important to have a rotational balance of the rotor 15. Since the multiple magnets 153 fixed to the inner surface 151n of the yoke 151 are arranged in point symmetry around the rotation axis X, the rotational balance of the rotor 15 is improved, and vibration and noise can be reduced when the rotor 15 is mounted on a structure.

[0070] Although the motor 1 of this embodiment is configured as an outer rotor type brushless motor, the present invention is also applicable to motors other than brushless motors. The present invention is also applicable to inner rotor type motors.

[0071] Although the motor of the present invention has been described above with reference to a preferred embodiment, the motor of the present invention is not limited to the configuration of the above embodiment. For example, in this embodiment, the first protrusion 201 and the second protrusion 202 are provided as two protrusions along the axis X direction, but the present invention is not limited to this, and a plurality of protrusions of different sizes, such as three or four, may be provided.

[0072] In the above embodiment, the first protruding portion 201 is provided on the lower side in the direction of the rotation axis X, and the second protruding portion 202 larger than the first protruding portion 201 is provided on the upper side, but the present invention is not limited to this, and the sizes of the first protruding portion 201 and the second protruding portion 202 may be reversed, that is, the first protruding portion 201 may be larger than the second protruding portion 202. In this case, the second protruding portion 202 serves as a guide and positioning, and the yoke 151 is assembled from the lower side in the direction of the rotation axis X.

[0073] In addition, those skilled in the art can appropriately modify the motor of the present invention in accordance with conventionally known knowledge. As long as the motor of the present invention is still provided after such modification, it is of course included in the scope of the present invention. [Explanation of symbols]

[0074] 1...motor, 11...stator housing, 13...stator, 15...rotor, 17...holder, 171...inner periphery, 173...outer periphery, 175...spoke, 19 (19a, 19b)...bearing, 111...inner periphery, 112...outer periphery, 115...connecting portion, 131...stator core, 132...annular portion, 133...teeth portion, 135...insulator, 139...coil, 151...yoke, 151n... Inner surface, 153...magnet, 171...inner circumference, 171d...convex portion, 171f...flange portion, 171h...through hole, 172...inner tube portion, 173...outer circumference end portion, 175...spokes, 201...first protrusion, 202...second protrusion, 500...jig, 501...piece, 700...receiving jig, 701...large diameter cylindrical portion, 702...small diameter cylindrical portion, 703...step surface, 704...recessed space, SP...gap.

Claims

1. A rotor; a stator disposed opposite the rotor; Equipped with The rotor has a yoke and a plurality of magnets, The yoke has a first protrusion and a second protrusion protruding toward the magnet, the first protruding portion is disposed on one side of the second protruding portion in a rotational axis direction of the rotor, The second protruding portion is larger in size in the circumferential direction than the first protruding portion. Motor.

2. The second protrusions are provided in a plurality in a circumferential direction of the yoke, and the magnet is disposed between the adjacent second protrusions. The motor according to claim 1 .

3. The number of the second protrusions is equal to the number of the magnets. The motor according to claim 2.

4. The outer circumferential surfaces of the first protruding portion and the second protruding portion have an arc shape. A motor according to any one of claims 1 to 3.

5. The magnets are in contact with each other in the circumferential direction. A motor according to any one of claims 1 to 4.

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