brushless motor

Abstract

The present invention provides a brushless motor that does not require a reinforcing member and can also improve the rigidity of the coil support wall. The first wall portion (38) and the second wall portion (39) forming the coil support wall (37) are connected to each other at an angle at the portion of the tooth front end portion (25) that protrudes relative to the tooth main body portion (24) in the circumferential direction of the core main body, and the thickness dimension (T1) of the second wall portion (39) in the radial direction of the core main body is greater than the thickness dimension (T2) of the first wall portion (38) ((T1)>(T2)). As a result, the rigidity of the coil support wall (37) can be improved without burying a reinforcing member in the coil support wall (37). Therefore, the collapse of the coil (Cu) ((Cv), (Cw)) to the radial inside can be effectively suppressed without complicating the structure or complicating the manufacturing process.

Description

Technical Field

[0001] The present invention relates to a brushless motor including a stator core and a rotor rotating relative to the stator core. Background Art

[0002] Brushless motors offer excellent controllability and quietness. They consist of a stator core (stator) with coils and a rotor (rotor) that rotates relative to the stator core. The stator core is provided with multiple teeth that protrude radially inward. Coils are wound around each of the teeth using methods such as concentrated winding. By sequentially supplying drive current to the multiple coils, the rotor rotates at a predetermined speed in a predetermined direction.

[0003] For example, Patent Document 1 describes a brushless motor having a stator core and a rotor. The brushless motor described in Patent Document 1 includes an annular core (stator core) with insulators (insulating material) attached to the axial ends of the core. The insulator covers the back yoke and teeth in the axial direction of the core, and a flange (coil support wall) is provided on the insulator to prevent the coil from collapsing radially inward.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2016-001947 Summary of the Invention

[0007] Problems to be solved by the invention

[0008] However, in the brushless motor described in Patent Document 1, a resin material or metal material (reinforcement member) having higher rigidity than the insulator is embedded inside the insulator to enhance the strength of the insulator. This complicates not only the structure of the insulator but also the manufacturing process of the insulator.

[0009] An object of the present invention is to provide a brushless motor that can improve the rigidity of a coil support wall without requiring a reinforcing member.

[0010] Technical means to solve the problem

[0011] A brushless motor according to the present invention includes a stator core and a rotor that rotates relative to the stator core, the brushless motor comprising: a core body provided on the stator core and formed in a cylindrical shape; a plurality of teeth provided on the core body and projecting radially inwardly from the core body; a tooth body provided on the teeth, the base end of the tooth body being connected to the core body; a tooth tip portion provided on the tip end of the tooth body and wider than the tooth body portion in the circumferential direction of the core body; and a resin coil support wall that overlaps with the tooth tip portion in the axial direction of the core body and supports a coil wound around the core body from the radially inward side of the core body, the coil support wall including a first wall portion and a second wall portion arranged in the circumferential direction of the core body, the first wall portion and the second wall portion being connected to each other at an angle at portions of the tooth tip portion that project beyond the tooth body portion in the circumferential direction of the core body, and the thickness of the second wall portion in the radial direction of the core body being greater than the thickness of the first wall portion.

[0012] Effects of the Invention

[0013] According to the present invention, the first wall portion and the second wall portion forming the coil support wall are connected to each other at an angle at the tooth front end portion protruding more than the tooth main body portion in the circumferential direction of the core main body portion, and the thickness dimension of the second wall portion in the radial direction of the core main body portion is greater than the thickness dimension of the first wall portion.

[0014] This increases the rigidity of the coil support wall without embedding a reinforcing member therein, thereby effectively preventing the coil from collapsing radially inward without complicating the structure or the manufacturing process. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a perspective view showing a motor with a speed reduction mechanism (motor cover omitted).

[0016] Figure 2 This is a perspective view showing the stator core and bus bar unit.

[0017] Figure 3 It is a three-dimensional diagram showing an insulator in a single form.

[0018] Figure 4 It is along Figure 3 The view of arrow A (with the iron core and coil recorded).

[0019] Figure 5 yes Figure 4 An enlarged view of the dotted circle B.

[0020] Figure 6This is a graph explaining the relationship between the wall thickness ratio and the amount of inner wall collapse.

[0021] Figure 7 It is along Figure 3 View of arrow C.

[0022] Figure 8 This is a comparison chart of the amount of inner wall collapse due to different coil support wall shapes.

[0023] [Explanation of Symbols]

[0024] 10: Motor with reduction mechanism

[0025] 11: Shell

[0026] 12: Speed ​​reduction mechanism housing

[0027] 13: Motor fixing part

[0028] 14: Output shaft

[0029] 15: Gear cover

[0030] 16: Connector connection part

[0031] 20: Brushless motor

[0032] 21: stator core (stator)

[0033] 22: Iron core body

[0034] 22a: Screw insertion hole

[0035] 22b: Elastic claw

[0036] 23: Teeth

[0037] 24: Tooth body

[0038] 25: Tooth front end

[0039] 25a: Tooth protrusion

[0040] 26: Rotor

[0041] 26a: Rotor body

[0042] 26b: Rotation axis

[0043] 27: Terminal block

[0044] 27a: Annular main body

[0045] 27b: Keep the convex part

[0046] 27c: snap-on claw

[0047] 30: Insulator

[0048] 31: Insulator body

[0049] 31a: Hooking claw

[0050] 31b: incision

[0051] 31c: Engagement recess

[0052] 32: Insert into wall

[0053] 33: First covering part

[0054] 34: Second covering part

[0055] 35: Tooth covering part

[0056] 36: Third covering part

[0057] 37: Coil support wall

[0058] 37a: First flat part

[0059] 37b: Second flat part

[0060] 38: First wall

[0061] 39: Second wall

[0062] A, C: Arrow

[0063] AC: Arc

[0064] B: dotted circle

[0065] BD1, BD2: Boundary lines

[0066] Cu, Cv, Cw: Coil

[0067] D: diameter size

[0068] L1, L2: length dimensions

[0069] MG: cylindrical magnet

[0070] S1, S2: fixing screws

[0071] SL: Slot

[0072] T1, T2: thickness dimensions

[0073] Tu, Tv, Tw: female terminals

[0074] W1, W2: width dimensions

[0075] α°: angle DETAILED DESCRIPTION

[0076] Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

[0077] Figure 1 A perspective view showing a motor with a speed reduction mechanism (motor cover omitted) is shown. Figure 2 A perspective view showing a stator core and a bus bar unit is shown. Figure 3 A perspective view showing an insulator in a single form is shown. Figure 4 Shown along Figure 3 The view of arrow A (with the iron core and coil recorded), Figure 5 Show Figure 4 The enlarged view of the dotted circle B, Figure 6 A graph illustrating the relationship between the wall thickness ratio and the amount of inner wall collapse is shown. Figure 7 Shown along Figure 3 The view of arrow C, Figure 8 A graph comparing the amount of inner wall collapse depending on the shape of the coil support wall is shown.

[0078] Figure 1 The illustrated motor 10 with a reduction mechanism is a compact, high-output, in-vehicle motor device. It can be used as a drive source for a windshield wiper system mounted on the front side of a vehicle (not shown). Specifically, the motor 10 with a reduction mechanism swings and drives the wiper arms (not shown) on the driver's and passenger's sides, respectively, via a linkage mechanism (not shown).

[0079] The motor 10 with a speed reduction mechanism includes a housing 11 that houses a worm reducer (not shown). Housing 11 is formed into a predetermined shape by injection molding a molten aluminum material or the like and includes a speed reduction mechanism housing portion 12 and a motor fixing portion 13. A worm and a worm wheel (worm reducer) are housed within speed reduction mechanism housing portion 12.

[0080] The worm forming the worm reducer rotates at high speed via the rotating shaft 26b forming the brushless motor 20. In contrast, the worm wheel meshing with the worm rotates at reduced speed and high torque. The output shaft 14 is then fixed to the rotation center of the worm wheel, and the rotational force (high output) of the output shaft 14 is transmitted to the linkage mechanism forming the wiper device.

[0081] The opening portion (upper side in the figure) of the speed reduction mechanism housing 12 is sealed by a gear cover 15 formed into a substantially flat plate shape from a resin material such as plastic. The gear cover 15 is fixed to the housing 11 by a total of three fixing screws S1.

[0082] A control board (not shown) that detects the rotation state of the output shaft 14 and controls the rotation state of the rotating shaft 26b is fixed inside the gear cover 15. In addition, a connector connection portion 16 to which an external connector (not shown) on the vehicle side is connected is integrally provided on the gear cover 15. Thus, a terminal holder 27 (see FIG. 1 ) that forms the control board and the brushless motor 20 is connected. Figure 2 ) supplies driving current, thereby causing the motor 10 with a reduction mechanism to operate.

[0083] A brushless motor 20 is fixed to the motor fixing portion 13 of the housing 11. The motor fixing portion 13 is open in a direction perpendicular to the axial direction of the output shaft 14. The axis of the output shaft 14 and the axis of the brushless motor 20 (rotating shaft 26b) are mutually perpendicular. Specifically, the motor fixing portion 13 is formed into a generally cylindrical shape, and a generally cylindrical stator core 21 is fitted radially inwardly of the motor fixing portion 13. The stator core 21 is securely fixed to the housing 11 by a pair of fixing screws S2.

[0084] Here, a resin motor cover covering the brushless motor 20 is fixed to the motor fixing portion 13. Figure 1 In the figure, the motor cover is omitted for easy understanding of the brushless motor 20 fixed to the motor fixing portion 13 .

[0085] like Figure 1 and Figure 2 As shown, the brushless motor 20 includes a stator core (stator) 21 fixed to the motor fixing portion 13. The stator core 21 is formed by laminating a plurality of annular steel plates (magnetic material) and includes a generally cylindrical core body 22. Furthermore, a total of six teeth 23 are integrally provided on the radially inner side of the core body 22. These teeth 23 project radially inward from the core body 22 and are arranged at equal intervals (60° intervals) circumferentially around the core body 22.

[0086] like Figure 4 As shown, when the stator core 21 is viewed from the axial direction, the teeth 23 are formed into a substantially T-shape and include a tooth body portion 24 and a tooth tip portion 25. Here, the boundary between the tooth body portion 24 and the tooth tip portion 25 is indicated by a boundary line BD1 (dash-dotted line).

[0087] The tooth body portion 24 is formed along the center portion (lower side in the figure) of the core body 22, with the base end (upper side in the figure) of the tooth body portion 24 connected to the radially inner side of the core body 22. Furthermore, a tooth tip portion 25 is integrally provided at the front end (lower side in the figure) of the tooth body portion 24. The tooth tip portion 25 has a width W1 relative to the circumferential direction of the core body 22 that is approximately twice the width W2 of the tooth body portion 24 relative to the circumferential direction of the core body 22 (W1 ≈ 2 × W2).

[0088] The tooth tips 25 on both sides of the core body 22 protrude from the tooth body 24 at the same height in the circumferential direction. These portions of the tooth tips 25 that protrude from the tooth body 24 form tooth protrusions 25a. This prevents the coils Cu (Cv, Cw) wound around the tooth body 24 from falling off the tooth body 24, and allows the electromagnetic force generated by supplying drive current to the coils Cu (Cv, Cw) to be efficiently transmitted to the rotor 26.

[0089] Here, if Figure 1 As shown, the rotor 26 is rotatably disposed radially inside the stator core 21 with a small gap (air gap) therebetween. The rotor 26 includes a rotor body 26a formed by laminating a plurality of steel plates (magnetic material), a cylindrical magnet MG fixed to the surface of the rotor body 26a, and a rotating shaft 26b fixed to the rotation center of the rotor body 26a.

[0090] Thus, in this embodiment, a brushless motor 20 with a surface permanent magnet (SPM) structure is employed, in which cylindrical magnets MG are fixed to the surface of the rotor body 26a. However, the brushless motor 20 is not limited to the SPM structure described above; a brushless motor with an interior permanent magnet (IPM) structure, in which multiple magnets (not shown) are embedded within the rotor body, may also be employed.

[0091] like Figure 2 As shown, a pair of screw insertion holes 22a are provided on the radially outer side of the core main body 22. A pair of fixing screws S2 (see FIG. 1 ) for fixing the stator core 21 to the housing 11 are inserted through the screw insertion holes 22a. Figure 1 ). Furthermore, a plurality of elastic claws 22b are provided radially outside the core body 22. These elastic claws 22b elastically contact the inner wall of the motor fixing portion 13, thereby preventing the core body 22 (stator core 21) from shaking relative to the motor fixing portion 13.

[0092] The coils Cu, Cv, and Cw corresponding to the U phase, V phase, and W phase are wound around a total of six teeth 23 through the insulator (insulating material) 30 by concentrated winding. Figure 2 As shown, the ends of the three-phase coil Cu, coil Cv, and coil Cw are respectively drawn outward from the axial ends of the stator core 21. Figure 1 and Figure 2 In the figure, in order to facilitate understanding of the arrangement relationship among the coils Cu, Cv, and Cw, the coils Cu, Cv, and Cw are shaded.

[0093] The coils Cu, Cv, and Cw, which are drawn outside the stator core 21, are electrically connected to one end of three female terminals Tu, Tv, and Tw, respectively, provided on the terminal block 27. Furthermore, the other ends of the female terminals Tu, Tv, and Tw are electrically connected to three female power supply terminals (not shown) provided on the control board. Specifically, when the motor with a speed reduction mechanism 10 is assembled, the terminal block 27 is housed within the housing 11.

[0094] Here, the terminal block 27 is formed into a roughly annular shape by injection molding a resin material such as plastic, and includes an annular main body 27a and a retaining protrusion 27b that protrudes axially toward the annular main body 27a. The three female terminals Tu, Tv, and Tw are respectively retained in the retaining protrusion 27b in a mutually insulated state. In addition, a plurality of engaging claws 27c (only two are shown in the figure) are provided on the annular main body 27a, and these engaging claws 27c are respectively engaged with a plurality of engaging recesses 31c provided on the insulator 30. As a result, the terminal block 27 is fixed relative to the stator core 21 without shaking.

[0095] like Figure 1 and Figure 2 As shown, insulators 30 having the same shape are mounted on both axial sides of the core body 22. Specifically, the pair of insulators 30 sandwich the core body 22 in the axial direction and are arranged in a mirror-symmetrical manner.

[0096] like Figure 3 As shown, the insulator 30 is formed into a substantially annular shape by injection molding a resin material (insulator) such as plastic, and includes an annular insulator body 31. The insulator body 31 is formed from the core body portion 22 (see Figure 2 ) overlaps with the axial end of the core body 22. In addition, the insulator body 31 has a portion that includes the three-phase coil Cu, coil Cv, and coil Cw (see Figure 2 ) are respectively assigned to the functions of the specified teeth 23.

[0097] Specifically, the insulator body 31 is provided with a plurality of hooking claws 31a for hooking the coils Cu, Cv, and Cw, or a plurality of cutouts 31b for the coils Cu, Cv, and Cw to pass through. Figure 2 As shown, the three-phase coil Cu, coil Cv, and coil Cw are arranged at the portion of the insulator body 31, that is, the end portion of the core body portion 22. Figure 2 As shown, a plurality of engagement recesses 31 c (only two are shown in the figure) into which the engagement claws 27 c of the terminal block 27 engage are provided on the outer peripheral portion of the insulator body 31 .

[0098] Furthermore, if Figure 3As shown, a plurality of insertion walls 32 formed in a substantially U-shape are integrally provided on the axial lower side (lower side in the figure) of the insulator body 31 and the radial inner side of the insulator body 31. These insertion walls 32 are inserted into the slots SL between adjacent teeth 23 from the axial direction of the core body 22 (see FIG. Figure 2 Furthermore, the insertion wall portion 32 includes a first covering portion 33 that covers the radially inner side of the core body portion 22 , and a pair of second covering portions 34 that respectively cover facing portions of adjacent teeth 23 .

[0099] In addition, a plurality of tooth covering portions 35 are provided on the radially inner side of the insulator body 31 so as to overlap the teeth 23 in the axial direction of the core body 22. A total of six tooth covering portions 35 are provided corresponding to the teeth 23. Figure 4 As shown, the tooth body 24 includes a third covering portion 36 that overlaps with the tooth main body portion 24 , and a coil support wall 37 that overlaps with the tooth tip portion 25 .

[0100] Here, the second covering portion 34 and the third covering portion 36 are arranged to surround the tooth body portion 24 and are configured to have approximately the same thickness. In contrast, the coil support wall 37 is provided upright in the axial direction of the core body 22. The height of the coil support wall 37 in the axial direction of the core body 22 is greater than its thickness in the radial direction of the core body 22.

[0101] The coil support walls 37 also have a function (coil protection function) of protecting the enamel coating provided on the surface of the coils Cu (Cv, Cw) from peeling off when the coils Cu (Cv, Cw) are wound around the teeth 23. Furthermore, the coil support walls 37 have a function of supporting the coils Cu (Cv, Cw) wound around the teeth 23 from the radially inner side of the core body 22 (coil support function).

[0102] Here, in order to increase the space factor of the coils Cu (Cv, Cw), it is necessary to strongly wind the coils Cu (Cv, Cw) around the teeth 23, etc., and it is desirable to increase the rigidity of the coil support wall 37. In addition, in order to reliably prevent the coils Cu (Cv, Cw) wound around the teeth 23 from collapsing (collapse) radially inward of the core body 22, it is also desirable to increase the rigidity of the coil support wall 37.

[0103] However, simply increasing the thickness of coil support wall 37 to improve rigidity makes it difficult to reduce the size and weight of motor 10 with a reduction mechanism, making it particularly difficult to use in vehicles. Therefore, in this embodiment, reinforcing members are not embedded within coil support wall 37, and the size of coil support wall 37 is minimized. Instead, the shape of coil support wall 37 is carefully considered to improve its rigidity.

[0104] Below, use Figure 4 、 Figure 5 and Figure 7 , the shape of the coil support wall 37 is described in detail. Figure 4 、 Figure 5 and Figure 7 As shown, the coil support wall 37 is provided in an axial direction of the core body 22 and is provided along the circumferential direction of the core body 22. The coil support wall 37 includes a first wall portion 38 and two second wall portions 39 arranged alternately in the circumferential direction of the core body 22.

[0105] The single first wall portion 38 is disposed in a portion corresponding to the tooth body portion 24 in the circumferential direction of the core body 22. Meanwhile, the two second wall portions 39 are disposed in portions corresponding to the tooth tip portions 25 that protrude relative to the tooth body portion 24 in the circumferential direction of the core body 22, that is, in portions corresponding to the pair of tooth protrusions 25a. Thus, the single first wall portion 38 is disposed between the two second wall portions 39.

[0106] In addition, the first wall portion 38 extends in the direction in which the tooth body portion 24 protrudes ( Figure 4 The second wall portion 39 is formed in a direction perpendicular to the first wall portion 38 and covers the portion of the boundary line BD1 in the axial direction of the core body 22. On the other hand, the second wall portion 39 is parallel to the tooth protrusion 25a and is inclined toward the radial inner side of the core body 22 relative to the first wall portion 38. In particular, as Figure 5 As shown by the symbol (<<) indicating parallelism, the surfaces of the second wall portion 39 and the tooth protrusion portion 25a on the coil Cu (Cv, Cw) side are parallel to each other.

[0107] like Figure 5 As shown, the first wall portion 38 and the second wall portion 39 are arranged along the rotor 26 (see Figure 1 ) are gently inclined with respect to each other in an arc-shaped manner on the outer peripheral portion, and on the opposite side of the rotor 26, the angle of the direction in which the second wall portion 39 extends relative to the direction in which the first wall portion 38 extends is set to α° (about 30°).

[0108] Furthermore, the first wall portion 38 and the second wall portion 39 are connected to each other at an angle at the portion of the tooth tip portion 25 that protrudes from the tooth body portion 24 in the circumferential direction of the core body portion 22, that is, the portion of the pair of tooth protrusions 25a. Figure 4 and Figure 5 As shown, the boundary line BD2 between the first wall portion 38 and the second wall portion 39 is located at the teeth protruding portion 25 a in the circumferential direction of the core body 22 .

[0109] Therefore, if Figure 5As shown, the first wall portion 38 extends to the portion of the tooth protrusion 25a with a length dimension L1 that is longer than the diameter dimension D of the coil Cu (Cv, Cw) (L1>d). Specifically, the first wall portion 38 extends to the portion of the second roll of the coil Cu (Cv, Cw) at the portion of the tooth protrusion 25a. As a result, the coil support wall 37 can reliably support the portion where the coil Cu (Cv, Cw) starts to be wound. This means that the coil Cu (Cv, Cw) can be more strongly wound on the tooth 23 (insulator 30). Therefore, the space factor of the coil Cu (Cv, Cw) can be increased, thereby realizing a motor 10 with a reduction mechanism that is small, lightweight, and has a higher output.

[0110] In addition, the thickness dimension T1 (average value) of the second wall portion 39 in the radial direction of the core body portion 22 is greater than the thickness dimension T2 (average value) of the first wall portion 38 in the radial direction of the core body portion 22 (T1>T2). Therefore, even if the coil Cu (Cv, Cw) collapses radially inward of the core body portion 22 and the first wall portion 38 collapses, its deformation is unlikely to be transmitted to the second wall portion 39. In other words, compared to a coil support wall (not shown) with a uniform thickness dimension, the overall rigidity of the coil support wall 37 can be improved. Furthermore, since the portion of the boundary line BD2 between the first wall portion 38 and the second wall portion 39 is a corner portion with an angle of α°, the corner portion functions as a reinforcing rib. In this respect, the rigidity of the coil support wall 37 can also be improved.

[0111] Furthermore, in the portion of the tooth protrusion 25a, the length L2 of the second wall portion 39 is greater than the length L1 of the first wall portion 38 (L2>L1). Specifically, the length L2 of the second wall portion 39 is approximately 1.3 times the length L1 of the first wall portion 38 (L2 ≈ 1.3 × L1). As a result, the second wall portion 39 functions as a guide wall when winding the coil Cu (Cv, Cw) onto the tooth 23 (insulator 30). This allows for easy and smooth winding operations.

[0112] Moreover, in Figure 5 In the relationship between the length dimension L1 of the first wall portion 38 and the length dimension L2 of the second wall portion 39 as shown, it is ideal to set the average thickness dimension T1 of the second wall portion 39 to 1.0 to 1.4 times the average thickness dimension T2 of the first wall portion 38. Furthermore, in this embodiment, the thickness dimension T1 is about 1.3 times the thickness dimension T2 (T1 ≒ 1.3 × T2). Thus, the following can be obtained: Figure 6 Characteristics as shown.

[0113] That is, when the average thickness dimension T1 of the second wall portion 39 is set to "1.0 times" the average thickness dimension T2 of the first wall portion 38, after the coil Cu (Cv, Cw) is wound, the coil support wall 37 collapses about 0.3 mm inwardly in the radial direction of the core body 22. The "collapse amount of 0.3 mm" is to prevent the coil support wall 37 from tightly contacting the rotor 26 in the small, lightweight, high-output motor 10 with a speed reduction mechanism suitable for vehicle use (see Figure 1 ), in other words, the maximum collapse of the motor 10 with a speed reduction mechanism as a product. Furthermore, the rigidity of the coil support wall 37 at this "1.0 times" is ensured by the angle α° at the boundary line BD2 between the first wall portion 38 and the second wall portion 39.

[0114] In contrast, if the average thickness dimension T1 of the second wall portion 39 is greater than "1.4 times" the average thickness dimension T2 of the first wall portion 38, the difference between thickness dimensions T1 and T2 increases, which may increase the amount of sink marks during injection molding of the insulator 30. In other words, manufacturing variations in the insulator 30 may occur between products. Consequently, there is a possibility that the coil support wall 37 may be deformed before the coils Cu (Cv, Cw) are packaged, and the amount of collapse of the coil support wall 37 after the coils Cu (Cv, Cw) are packaged may become uncontrollable.

[0115] Based on the above, in this embodiment, the effective range of the thickness ratio of the average thickness dimension T1 of the second wall portion 39 to the average thickness dimension T2 of the first wall portion 38 is set to 1.0 to 1.4 times. This allows for a motor 10 with a speed reduction mechanism that is compact, lightweight, and high-output, suppresses the amount of collapse of the coil support wall 37 after winding the coils Cu (Cv, Cw) to less than 0.3 mm, and significantly reduces the occurrence of defective products.

[0116] Furthermore, if Figure 7 As shown, the coil support wall 37 (first wall portion 38 and second wall portion 39) is ideally formed into a substantially rectangular shape when viewed radially inward from the insulator 30. Specifically, the shape of the coil support wall 37 is determined to include a first flat portion 37a formed along the circumferential direction (left-right direction in the figure) of the core body 22, and a second flat portion 37b formed along the axial direction (up-down direction in the figure) of the core body 22. Furthermore, an arc portion AC having a predetermined curvature is provided at the connection between the first flat portion 37a and the second flat portion 37b to prevent the coils Cu (Cv, Cw) from catching on the coil support wall 37 during winding.

[0117] Thus, by setting the coil support wall 37 to a substantially rectangular shape and making the thickness dimension T1 about 1.3 times the thickness dimension T2 as described above, as shown in FIG. Figure 8 As shown, the amount of collapse of the coil support wall 37 can be further reduced. Specifically, the light shaded graph (right side in the figure) represents a substantially rectangular coil support wall 37 with a flat portion (the present invention), and the dark shaded graph (left side in the figure) represents a circular arc coil support wall without a flat portion (comparative example, see Figure 7 ).according to Figure 8 As can be seen from the graph, the amount of collapse can be reduced by about 37% (comparative example).

[0118] As described in detail above, according to this embodiment, the first wall portion 38 and the second wall portion 39 forming the coil support wall 37 are connected to each other at an angle at the portion of the tooth front end portion 25 (tooth protrusion 25a) that protrudes more than the tooth main body portion 24 in the circumferential direction of the core main body portion 22, and the thickness dimension T1 of the second wall portion 39 in the radial direction of the core main body portion 22 is greater than the thickness dimension T2 of the first wall portion 38 (T1>T2).

[0119] This improves the rigidity of the coil support wall 37 without embedding a reinforcing member in the coil support wall 37. Therefore, radially inward collapse of the coil Cu (Cv, Cw) can be effectively suppressed without complicating the structure or the manufacturing process.

[0120] According to the present embodiment, the first wall portion 38 is formed in a direction perpendicular to the direction in which the tooth body portion 24 protrudes, and the second wall portion 39 is inclined radially inward of the core body 22 relative to the first wall portion 38 .

[0121] This improves the rigidity of the coil support wall 37 while allowing the coil support wall 37 to conform to the shape of the tooth tip portion 25 , thereby maintaining a small gap (clearance) between the rotor 26 and the stator core 21 at an appropriate value.

[0122] Furthermore, according to the present embodiment, the second wall portion 39 is parallel to the portion of the tooth tip portion 25 that protrudes beyond the tooth body portion 24 .

[0123] This allows substantially uniform rigidity to be achieved across substantially the entire region of the second wall portion 39. Therefore, the rigidity of the coil support wall 37 can be easily controlled (simulated), thereby facilitating the design of the insulator 30.

[0124] Furthermore, according to the present embodiment, the thickness dimension T1 of the second wall portion 39 is 1.0 to 1.4 times the thickness dimension T2 of the first wall portion 38 .

[0125] As a result, the amount of collapse of the coil support wall 37 can be minimized, which allows for a small, lightweight, high-output motor 10 with a reduction mechanism suitable for vehicle use. Furthermore, the occurrence of sink marks generated during the manufacture of the insulator 30 can be suppressed, thereby preventing the accuracy of the insulator 30 from varying between products.

[0126] Furthermore, according to the present embodiment, the coil support wall 37 includes a first flat portion 37 a formed along the circumferential direction of the core body 22 and a second flat portion 37 b formed along the axial direction of the core body 22 .

[0127] This can further reduce the amount of collapse of the coil support wall 37 .

[0128] The present invention is not limited to the above-described embodiment and can, of course, be modified in various ways without departing from the spirit and scope of the present invention. For example, the above-described embodiment illustrates a case where the brushless motor 20 is applied to the motor 10 with a speed reduction mechanism used as a drive source for a wiper device, but the present invention is not limited thereto. For example, the present invention can also be applied as a drive source for a motor with a speed reduction mechanism used in other in-vehicle equipment, such as a power sliding door device or a power window device.

[0129] In addition, the material, shape, size, number, installation location, etc. of each component in the above-described embodiment are arbitrary as long as the present invention can be realized, and are not limited to the above-described embodiment.

Claims

1. A brushless motor comprising: stator core; as well as The rotor rotates relative to the stator core, and the brushless motor is characterized by having: The core body is provided on the stator core and is formed into a cylindrical shape; a plurality of teeth, provided on the core body and radially protruding toward the radial inner side of the core body; a tooth body portion, provided on the tooth, with a base end side connected to the core body portion; a tooth front end portion, provided at the front end side of the tooth main body portion and wider than the tooth main body portion in the circumferential direction of the core main body portion; as well as The resin coil support wall overlaps the tooth tip portion in the axial direction of the core body and supports the coil wound on the core body from the radial inner side of the core body. The coil support wall includes a first wall portion and a second wall portion arranged in a circumferential direction of the core body portion. The portion of the tooth tip portion that protrudes from the tooth body portion becomes a tooth protrusion portion. The first wall portion and the second wall portion are connected to each other at an angle at portions of the tooth protrusion that protrude more than the tooth body portion in the circumferential direction of the core body portion, and the thickness of the second wall portion in the radial direction of the core body portion is greater than the thickness of the first wall portion. The first wall portion extends to a portion of the tooth protrusion with a length dimension longer than a diameter dimension of the coil.

2. The brushless motor according to claim 1, wherein: The first wall portion is formed along a direction perpendicular to a direction in which the tooth body portion projects, and the second wall portion is inclined radially inward of the core body portion relative to the first wall portion.

3. The brushless motor according to claim 1 or 2, wherein: The second wall portion is parallel to a portion of the tooth tip portion that protrudes beyond the tooth body portion.

4. The brushless motor according to claim 1 or 2, wherein: The thickness of the second wall portion is 1.0 to 1.4 times the thickness of the first wall portion.

5. The brushless motor according to claim 1 or 2, characterized in that: The coil supporting wall comprises: a first flat portion formed along the circumference of the core body; and The second flat portion is formed along the axial direction of the core body.

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