Stator and electric motor

Abstract

To provide a stator and an electric motor which can improve a space factor of a coil.SOLUTION: An outer wall part 67 of an insulator comprises a pull-in slit 68 for pulling in a coil 24 from the outside in a radial direction to the inside in the radial direction, wherein a first side 68a and a second side 68b are arranged on both sides between a side face coating part straight line L passing through a tooth side face coating part when viewed from an axial direction, the second side 68b is arranged closer to the center in a circumferential direction of teeth than the first side 68a, width between the side face coating part straight line L and the second side 68b is larger than a line diameter D of the coil 24 when viewed from the axial direction when the coil 24 is drawn around to straddle the root of the corresponding teeth and pulled in the pull-in slit 68, and the width between the side face coating part straight line L and the first side 68a is smaller than the line diameter D of the coil 24 when viewed from the axial direction when the coil 24 is drawn around from the opposite direction of the corresponding teeth and pulled in the pull-in slit 68.SELECTED DRAWING: Figure 16

Description

[Technical Field]

[0001] The present invention relates to a stator and an electric motor. [Background technology]

[0002] An electric motor includes, for example, a stator around which a coil is wound, and a rotor that is rotatable relative to the stator and has a permanent magnet. The stator is made of a magnetic material and has an annular core body (circular core portion) and teeth (magnetic pole teeth) that protrude radially from the core body. The coil is wound around the teeth from above an insulator. The insulator is made of an insulating resin. The insulator insulates the teeth from the coil. With this configuration, when current is applied to the coil, a magnetic field is generated in the teeth. Magnetic attractive and repulsive forces are generated between this magnetic field and the permanent magnet, causing the rotor to rotate continuously.

[0003] The torque performance of an electric motor is greatly affected by the space factor of the coil used to generate the magnetic field. For this reason, various technologies have been proposed to improve the space factor of the coil. For example, a technology has been disclosed in which the insulator is tilted so that the height from the surface of the teeth changes in a fixed direction between the tip and base of the teeth. With this configuration, when the coil is wound on top of the insulator, the coil is wound while leaning in a fixed direction. This allows the coil to be wound with as few gaps as possible, thereby improving the space factor of the coil as much as possible. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-247789 Summary of the Invention [Problem to be solved by the invention]

[0005] In recent years, however, there has been a demand for further improvement in the coil space factor.

[0006] Therefore, the present invention provides a stator and an electric motor that can improve the space factor of the coil. [Means for solving the problem]

[0007] In order to solve the above problems, a stator according to the present invention includes an insulator attached to an annular core body and a plurality of teeth protruding radially from the core body to insulate the teeth from coils wound around the teeth, the annular core body to which the insulator is attached, the teeth protruding radially inward from an inner peripheral surface of the core body, and the coils being routed along the core body and wound around the teeth via the insulator, wherein the insulator comprises tooth end face covering portions that cover axial end faces of the teeth, tooth side face covering portions that cover circumferential side faces of the tooth body extending radially of the teeth, outer wall portions that protrude in the axial direction from radially outer ends of the tooth end face covering portions, and inner wall portions that protrude in the axial direction from radially inner ends of the tooth end face covering portions. and the outer wall portion has a pull-in slit formed for each tooth for pulling the coil from the radially outer side to the radially inner side of the outer wall portion, a first side edge and a second side edge opposing each other in the circumferential direction of the pull-in slit are arranged on either side of a side surface covering portion straight line passing through the tooth side surface covering portion as viewed in the axial direction, the second side edge is arranged closer to the circumferential center of the tooth than the first side edge, and when the coil is pulled across the base of the corresponding tooth and pulled into the pull-in slit, the width between the side surface covering portion straight line and the second side edge as viewed in the axial direction is larger than the wire diameter of the coil, and when the coil is pulled from the opposite direction to the corresponding tooth and pulled into the pull-in slit, the width between the side surface covering portion straight line and the first side edge as viewed in the axial direction is smaller than the wire diameter of the coil. [Effects of the Invention]

[0008] According to the present invention, an increase in the thickness of the insulator at the inclined portion can be prevented, and therefore deterioration of moldability due to heat sink or the like can be suppressed when the insulator is molded from resin. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a perspective view of a motor with a reducer according to an embodiment of the present invention; [Figure 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Figure 3] FIG. 2 is a perspective view of a stator according to an embodiment of the present invention. [Figure 4] 1 is a plan view of a stator according to an embodiment of the present invention, viewed from an axial direction, with a terminal holder removed. [Figure 5] FIG. 2 is a perspective view of an insulator according to an embodiment of the present invention. [Figure 6] FIG. 2 is a perspective view of a first insulator according to the embodiment of the present invention. [Figure 7] FIG. 7 is a view taken along arrow VII in FIG. 5. [Figure 8] FIG. 8 is a view taken along arrow VIII in FIG. 6. [Figure 9A] Cross-sectional view taken along line IXA-IXA in Figure 7. [Figure 9B] 9 is a cross-sectional view taken along line IXB-IXB in FIG. 7. [Figure 9C] FIG. 8 is a cross-sectional view taken along line IXC-IXC in FIG. 7. [Figure 10] View from the X arrow in Figure 6. [Figure 11] FIG. 3 is a perspective view of a second insulator according to the first embodiment of the present invention. [Figure 12] FIG. 2 is a comparative explanatory view of a mold according to the first embodiment of the present invention. [Figure 13] FIG. 2 is a plan view of the jig according to the first embodiment of the present invention, viewed from the axial direction. [Figure 14] FIG. 3 is a plan view showing a state in which the coil is pulled into the pull-in slit when the coil is wound clockwise in the first embodiment of the present invention. [Figure 15]FIG. 3 is a perspective view showing a state in which the coil is pulled into the pull-in slit when the coil is wound clockwise in the first embodiment of the present invention. [Figure 16] FIG. 3 is a plan view showing a state in which the coil is pulled into the pull-in slit when the coil is wound counterclockwise in the first embodiment of the present invention. [Figure 17] FIG. 3 is a perspective view showing a state in which the coil is pulled into the pull-in slit when the coil is wound counterclockwise in the first embodiment of the present invention. [Figure 18] 3 is a plan view showing a state of the coil being drawn out through the drawing slit and wound counterclockwise in the first embodiment of the present invention. FIG. [Figure 19] 1 is a plan view showing a state of a coil that is drawn out through a drawing slit and wound clockwise in the first embodiment of the present invention. FIG. [Figure 20] FIG. 2 is an explanatory diagram showing a state in which a coil is wound on an insulator in the first embodiment of the present invention. [Figure 21A] 5A and 5B are explanatory diagrams illustrating the inclination angle of an inclined portion according to the embodiment of the present invention. [Figure 21B] FIG. 10 is an explanatory diagram of the inclination angle of an inclined portion in a comparative example. [Figure 22] FIG. 10 is a plan view of a first insulator according to a second embodiment of the present invention, as viewed from the axial direction. [Figure 23] 23 is a cross-sectional view taken along line XXIII-XXIII in FIG. 22. DETAILED DESCRIPTION OF THE INVENTION

[0010] Next, an embodiment of the present invention will be described with reference to the drawings.

[0011] <Motor with reducer> Fig. 1 is a perspective view of a speed reducer-equipped motor 1. Fig. 2 is a cross-sectional view taken along line II-II in Fig. 1. The motor 1 with a speed reducer is used, for example, as a drive source for a wiper device of a vehicle. As shown in FIGS. 1 and 2, the motor with a reducer 1 includes an electric motor 2, a speed reducer unit 3 that reduces the rotation of the electric motor 2 and outputs the reduced rotation, and a controller 4 that controls the drive of the electric motor 2. In the following description, the term "axial direction" refers to a direction parallel to the central axis of the shaft 31 of the electric motor 2 (the rotation axis C1 of the electric motor 2). The term "circumferential direction" refers to the circumferential direction (rotation direction) of the shaft 31. The term "radial direction" refers to the radial direction of the shaft 31 that is perpendicular to the axial and circumferential directions.

[0012] <Electric motor> The electric motor 2 includes a motor case 5, a cylindrical stator 8 housed in the motor case 5, and a rotor 9 disposed radially inside the stator 8 and rotatable relative to the stator 8. The electric motor 2 is a so-called brushless motor, which does not require brushes to supply power to the stator 8.

[0013] <Motor case> The motor case 5 is made of a material with excellent heat dissipation properties, such as an aluminum alloy. The motor case 5 is made up of a first motor case 6 and a second motor case 7, which are configured to be separable in the axial direction. The first motor case 6 and the second motor case 7 are each formed in a cylindrical shape with a bottom.

[0014] The first motor case 6 has a bottom 10 integrally formed with the gear case 40 of the reduction gear unit 3. A through hole 10a is formed in the radial center of the bottom 10, allowing the shaft 31 of the electric motor 2 to be inserted therethrough. Outer flanges 16, 17 that protrude radially outward are formed in the openings 6a, 7a of the first motor case 6 and the second motor case 7, respectively. These outer flanges 16, 17 are butted against each other, and the first motor case 6 and the second motor case 7 are integrated with each other by bolts 25. The motor case 5 has an internal space closed by the first motor case 6 and the second motor case 7, and the stator 8 and rotor 9 are housed in this internal space.

[0015] <Rotor> The rotor 9 is rotatably disposed radially inside the stator 8 via a small gap. The rotor 9 includes a shaft 31, a cylindrical rotor core 32 fitted and fixed to the shaft 31, a plurality of magnets (not shown) assembled to the outer periphery of the rotor core 32, and a magnet cover 32a that covers the rotor core 32 from above the magnets.

[0016] The shaft 31 is formed integrally with the worm shaft 44 that constitutes the speed reducer 3. However, this is not a limitation, and the worm shaft 44 may be formed separately from the shaft 31 and connected to the end of the shaft 31. The shaft 31 and the worm shaft 44 are rotatably supported by the gear case 40 via bearings 46, 47. The shaft 31 and the worm shaft 44 rotate around the rotation axis C1. For example, a ferrite magnet is used as the magnet. However, this is not a limitation, and the magnet may also be a neodymium bonded magnet, a neodymium sintered magnet, or the like.

[0017] <Deceleration section> The reduction unit 3 includes a gear case 40 integrated with the motor case 5 and a worm reduction mechanism 41 housed within the gear case 40. The gear case 40 is made of a metal material with excellent heat dissipation properties, such as an aluminum alloy. The gear case 40 is formed in a box shape with an opening 40a on one side. The gear case 40 has a gear housing portion 42 that houses the worm reduction mechanism 41 inside. In addition, an opening 43 that connects the through hole 10a of the first motor case 6 to the gear housing portion 42 is formed in the side wall 40b of the gear case 40 at the location where the first motor case 6 is integrally formed.

[0018] A cylindrical bearing boss 49 is formed to protrude from the bottom wall 40c of the gear case 40. The bearing boss 49 rotatably supports the output shaft 48 of the worm reduction mechanism 41, and a plain bearing (not shown) is disposed on the inner periphery. An O-ring (not shown) is attached to the inner periphery of the tip of the bearing boss 49. In addition, a plurality of ribs 52 protrude from the outer periphery of the bearing boss 49 to ensure rigidity.

[0019] The worm reduction mechanism 41 housed in the gear housing 42 is composed of a worm shaft 44 formed integrally with the shaft 31 of the rotor 9, and a worm wheel 45 meshed with the worm shaft 44. Both axial ends of the worm shaft 44 are supported by the gear case 40 via bearings 46, 47 so as to be rotatable about a rotation axis C1. An output shaft 48 of the electric motor 2 is coaxially and integrally provided on the worm wheel 45. The worm wheel 45 and the output shaft 48 are arranged so that their rotation axes are perpendicular to the rotation axis C1 of the worm shaft 44 (shaft 31 of the electric motor 2). The output shaft 48 protrudes to the outside through a bearing boss 49 of the gear case 40. A spline 48a is formed at the protruding tip of the output shaft 48, which can be connected to an object to be driven by the motor.

[0020] In addition, a sensor magnet (not shown) is provided on the worm wheel 45. The position of this sensor magnet is detected by a magnetic detection element 50 (described later) provided in the controller 4. In other words, the rotational position of the worm wheel 45 is detected by the magnetic detection element 50 of the controller 4.

[0021] <controller> The controller 4 has a controller board 51 on which a magnetic detection element 50 is mounted. The controller board 51 is disposed in the opening 40a of the gear case 40 so that the magnetic detection element 50 faces the sensor magnet of the worm wheel 45. The opening 40a of the gear case 40 is closed by a cover 53.

[0022] The controller board 51 is electrically connected to the coil 24 (described later) of the stator 8. The terminals of a connector 11 (see FIG. 1) provided on a cover 53 are also electrically connected to the controller board 51. In addition to the magnetic detection element 50, the controller board 51 is also mounted with a power module (not shown) made up of switching elements such as FETs (Field Effect Transistors) that control the drive voltage supplied to the coil 24, a capacitor (not shown) that smooths the voltage, and the like.

[0023] <Stator and terminal holder> Fig. 3 is a perspective view of the stator 8. Fig. 4 is a plan view of the stator 8 as seen from the axial direction, showing a state in which the terminal holder 85 has been removed. Fig. 4 also shows a part of the insulator 26 cut away. As shown in Figures 3 and 4, the stator 8 includes a cylindrical stator core 20 whose central axis coincides with the rotation axis C1, an insulator 26 attached to the stator core 20, and a plurality of coils 24 having a three-phase (U phase, V phase, W phase) structure wound around the stator core 20 from above the insulator 26.

[0024] A terminal holder 85 is provided on the stator core 20. The terminal holder 85 is integrally formed with terminals 86, a holder body 87 that holds the terminals 86, and a cover portion 88 that covers one axial end portion of the stator core 20. The terminals 86 are connected to the terminal portions 24a of the coils 24 of each phase, and are also connected to a connector (not shown) extending from the controller board 51. The cover portion 88 is integrally formed with an annular end face cover portion 88a arranged opposite to the axial direction of the stator core 20, and an outer circumferential cover portion 88b extending from the outer peripheral edge of the end face cover portion 88a toward the stator core 20 and covering the insulator 26 from the radially outer side.

[0025] The holder body 87 is formed by rising from a part of the end face cover portion 88a toward the opposite side to the stator core 20. The end face cover portion 88a and the outer circumferential cover portion 88b have cut-out portions 88c formed at locations corresponding to the holder body 87. The holder main body 87 is formed in the shape of a rectangular parallelepiped that is long in the axial and circumferential directions. A connector (not shown) extending from the controller board 51 is attached to the holder main body 87. The holder main body 87 is formed with three terminal accommodating recesses 87a that are aligned in the longitudinal direction when viewed from the axial direction. The terminals 86 are accommodated and held in these terminal accommodating recesses 87a. The terminals 86 are then connected to a connector (not shown) extending from the controller board 51.

[0026] The stator core 20 is formed by laminating a plurality of electromagnetic steel plates 20p. However, the present invention is not limited to this, and the stator core 20 may be formed by, for example, pressure molding soft magnetic powder. The stator core 20 has a cylindrical core body 21, a plurality of teeth 22 (six in the first embodiment) protruding radially inward from the inner circumferential surface of the core body 21, and two fixing portions 23 integrally molded on the outer circumferential surface of the core body 21. The teeth 22 have tooth bodies 28 protruding radially from the inner circumferential surface of the core body 21, and flange portions 29 integrally molded on tooth tip portions 28a, which are the radially inner ends of the tooth bodies 28 on the opposite side from the core body 21. A coil 24 is wound around the tooth bodies 28 from above an insulator 26.

[0027] The flange 29 extends in the circumferential direction. The inner peripheral surface of the flange 29 is formed along a circle centered on the rotation axis C1. Between adjacent teeth 22 in the circumferential direction, a dovetail-shaped slot 27 is formed by the inner peripheral surface of the core body 21, the circumferential side surface of the tooth body 28, and the outer peripheral surface of the flange 29 when viewed in the axial direction.

[0028] The fixing portions 23 protrude radially outward from the outer peripheral surface of the core body 21 and are arranged at 180° intervals in the circumferential direction. The fixing portions 23 are formed with bolt insertion holes 23a that penetrate in the axial direction.

[0029] With this configuration, the outer peripheral surface of the core body 21 is fitted into and housed within the inner peripheral surface of the first motor case 6. Then, a tapping screw (not shown) is inserted into the bolt insertion hole 23a of the fixing portion 23, and this tapping screw is screwed into the bottom portion 10 of the first motor case 6, thereby fastening and fixing the stator core 20 to the first motor case 6. The second motor case 7 is then placed over the stator core 20 fixed in this manner. The second motor case 7 is then fixed to the first motor case 6.

[0030] [First embodiment] <Insulator> Fig. 5 is a perspective view of the insulator 26. Fig. 5 shows the insulator 26 in a state where it is attached to the stator core 20. Fig. 6 is a perspective view of a first insulator 61 of the insulator 26. The insulators 26 are intended to insulate the teeth 22 from the coils 24, and are made of insulating resin.

[0031] 5 and 6, the insulator 26 is configured to be divided into two parts in the axial direction so as to be attached to both axial sides of the stator core 20. That is, the insulator 26 includes a first insulator 61 attached from one axial side (upper side in FIG. 5) of the stator core 20, and a second insulator 62 attached from the other axial side (lower side in FIG. 5) of the stator core 20. In the following description, for ease of understanding, the first insulator 61 side will be referred to as the upper side, and the second insulator 62 side will be referred to as the lower side.

[0032] The first insulator 61 is formed by integrally molding a core body covering portion 63 that covers the core body 21 and a tooth covering portion 64 that covers the teeth 22. The core body covering portion 63 has an annular core end face covering portion 65 that covers the axial end face of the core body 21, a core side face covering portion 66 that protrudes downward from a lower face 65a of the core end face covering portion 65, and a cylindrical outer wall portion 67 that protrudes upward from an upper face 65b of the core end face covering portion 65.

[0033] The core side surface covering portion 66 is disposed on the inner peripheral edge of the core end surface covering portion 65. The core side surface covering portion 66 covers the inner peripheral surface of the core body 21. The outer wall portion 67 is disposed closer to the outer peripheral edge of the core end surface covering portion 65. The outer peripheral cover portion 88b of the terminal holder 85 is disposed radially outward of the outer wall portion 67.

[0034] The outer wall portion 67 is formed with a lead-in slit 68 and an extraction slit 69 at positions corresponding to each of the tooth covering portions 64 . The draw-in slit 68 is for drawing the coil 24 from the radially outer side to the radially inner side of the outer wall portion 67. The draw-out slit 69 is for drawing the coil 24 from the radially inner side to the radially outer side of the outer wall portion 67. Details of drawing or drawing the coil 24 through each slit 68, 69 and the detailed positions of each slit 68, 69 will be described later.

[0035] A coil pull-out portion 77 is integrally molded at the base of a tooth covering portion 64A (hereinafter, this tooth covering portion 64A will be referred to as the specific tooth covering portion 64A) that covers a specific tooth 22A (see Figure 4, hereinafter, this tooth 22A will be referred to as the specific tooth 22A) among the multiple teeth 22 in the core end face covering portion 65 and the outer wall portion 67. The coil lead-out portion 77 is a portion where the terminal portion 24a (see FIG. 3) of the coil 24 of each phase is led upward. The terminal holder 85 is arranged so that the cutout portion 88c of the terminal holder 85 fits into the coil lead-out portion 77. In other words, the terminal 86 of the terminal holder 85 is arranged directly above the coil lead-out portion 77.

[0036] The coil lead-out portion 77 is formed with a plurality of coil guide recesses 78 (for example, three, since the coil 24 in the first embodiment has a three-phase structure) that separately regulate the lead-out locations of the terminal portions 24a of the coils 24 of each phase. These coil guide recesses 78 are arranged in a concentrated manner lined up in the circumferential direction. Each coil guide recess 78 is integrally formed with a coil holding claw 78a that protrudes along the circumferential direction. The terminal portions 24a of the coils 24 of each phase are separately led upward through each coil guide recess 78. The led-out terminal portions 24a of the coils 24 of each phase are guided to terminals 86 of a terminal holder 85 while being held by the coil holding claws 78a, and connected to these terminals 86.

[0037] Fig. 7 is a view seen from the arrow VII in Fig. 5. Fig. 8 is a view seen from the arrow VIII in Fig. 6. Fig. 9A is a cross-sectional view taken along line IXA-IXA in Fig. 7. Fig. 9B is a cross-sectional view taken along line IXB-IXB in Fig. 7. Fig. 9C is a cross-sectional view taken along line IXC-IXC in Fig. 7. As shown in Figures 5 to 9C, tooth covering portion 64 has a radially long tooth end surface covering portion 71 extending from core end surface covering portion 65 along the surface direction of core end surface covering portion 65, a tooth side surface covering portion 72 protruding downward from both circumferential sides (both short-side ends) of tooth end surface covering portion 71, a flange side surface covering portion 73 protruding circumferentially outward from the radial inner end of tooth side surface covering portion 72, and an inner wall portion 74 joined to the radial inner end of tooth end surface covering portion 71 and the upper end of flange side surface covering portion 73 and extending upward from the upper end of flange side surface covering portion 73.

[0038] The tooth end surface covering portion 71 covers the upper end of the tooth main body 28. Here, the surface of the tooth end surface covering portion 71 opposite the upper end of the tooth main body 28 is referred to as the front surface 71a, and the surface facing the upper end of the tooth main body 28 is referred to as the back surface 71b. A sloping portion 75 is formed over most of the front surface 71a of the tooth end surface covering portion 71, extending radially. The sloping portion 75 is sloping so that its height from the axial end face of the tooth main body 28 gradually decreases radially outward. As a result, the circumferential width of the sloping portion 75 gradually increases radially outward.

[0039] On the surface 71a of the tooth end face covering portion 71, a pin contact recess (an example of the recess in the claims) 76 having a circular shape when viewed in the axial direction is formed on the radially inner side. The pin contact recess 76 is a location where an ejector pin of a resin molding machine (not shown) contacts during the resin molding of the first insulator 61. The pin contact recess 76 is formed parallel to the axial end face of the tooth body 28. The detailed position of the pin contact recess 76 is such that the position of the center 76c of the pin contact recess 76 is located radially inward of the radial center 75c of the inclined portion 75. The pin contact recess 76 is formed so as to fit on the inclined portion 75. Since the pin contact recess 76 is arranged on the radially inner side, its diameter becomes smaller compared to the case where it is arranged on the radially outer side.

[0040] On the back surface 71b of the tooth end face covering portion 71, an inclined portion parallel portion 95 (a recessed portion) is formed. The inclined portion parallel portion 95 is formed corresponding to the shape of the inclined portion 75. For this reason, in a region where the inclined portion parallel portion 95 is present, the wall thickness T1 of the tooth end face covering portion 71 is constant. Such an inclined angle θ1 of the inclined portion 75 is smaller than 45°. The inclined angle θ1 refers to the inclined angle with respect to the upper end (virtual plane Kp) of the tooth body 28.

[0041] Furthermore, on the back surface 71b, a tooth parallel portion 96 (a recessed portion) is formed radially inward of the inclined portion parallel portion 95. The tooth parallel portion 96 is formed parallel to the axial end face of the tooth body 28. For this reason, in a region where the tooth parallel portion 96 is present, the wall thickness T2 of the tooth end face covering portion 71 gradually increases toward the radially outer side. That is, T1 < T2. Thereby, the wall thickness at the connection portion with the inner wall portion 74 of the tooth end face covering portion 71 becomes large, and the strength of the inner wall portion 74 can be increased. Therefore, even if a radially inward stress is applied to the inner wall portion 74 due to the winding of the coil 24, deformation of the inner wall portion 74 can be suppressed.

[0042] Here, the boundary line BL between the inclined portion parallel portion 95 and the tooth parallel portion 96 is located along part of the outer periphery of the pin abutment recess 76 when viewed from the axial direction. Furthermore, in the region where the pin abutment recess 76 is located, the tooth parallel portion 96 is located on the back surface 71b. That is, in the region where the pin abutment recess 76 is located, the thickness T3 of the tooth end face covering portion 71 is constant. Furthermore, T1 = T3 is set.

[0043] Additionally, abutment portions 97 are formed on the back surface 71b, and are provided flush with the lower surface 65a of the core end surface covering portion 65. The abutment portions 97 abut against the tooth main body 28. The inclined portion parallel portions 95 and the tooth parallel portions 96 are further away from the tooth main body 28 in the axial direction than the abutment portions 97. In other words, the inclined portion parallel portions 95 and the tooth parallel portions 96 are recessed relative to the abutment portions 97.

[0044] The tooth side surface covering portions 72 cover the circumferential side surfaces of the tooth bodies 28 of the teeth 22. The flange side surface covering portions 73 cover the outer peripheral surfaces of the flange portions 29 of the teeth 22. The tooth side surface covering portions 72 and the flange side surface covering portions 73 are connected to the core side surface covering portion 66 of the core body covering portion 63, forming a cylindrical skirt portion 79 that protrudes downward from the tooth end surface covering portions 71 and the core end surface covering portion 65. In other words, the skirt portion 79 is interposed in the slot 27 of the stator core 20.

[0045] A tip portion 79a (an example of the skirt tip portion in the claims) at the lower end of the skirt portion 79 is formed obliquely so that the protruding height from the tooth end surface covering portion 71 and the core end surface covering portion 65 gradually changes along the circumferential direction. A flat portion 79b parallel to the tooth end surface covering portion 71 and the core end surface covering portion 65 is formed at the location of the tip portion 79a of the skirt portion 79 where the protruding height is lowest.

[0046] Furthermore, a parting line PL that is parallel to the tooth side surface covering portion 72 and the flange side surface covering portion 73 is set on the skirt portion 79 closer to the tip end portion 79a than the center in the up-down direction. The parting line PL is the location where an upper mold 91 and a lower mold 92 (see FIG. 12) of a mold 90 used when resin molding the first insulator 61 overlap. In other words, the parting line PL is the line along which the mold 90 used for resin molding is divided.

[0047] A recess 81 is formed on the inner surface 79c of the skirt portion 79 (the side surface of the tooth side covering portion 72, the flange side covering portion 73, and the core side covering portion 66 opposite the stator core 20) via a minute step 80 along the entire length from the parting line PL to the tip end 79a. As a result, the thickness of the lower part of the skirt portion 79 is slightly thinner than the thickness of the upper part on either side of the parting line PL. By forming the minute step 80 at the parting line PL, even if the parting line PL is set halfway along the side of the resin molded product (skirt portion 79), the generation of burrs at this parting line PL during resin molding can be suppressed. The dimension of the minute step 80 is, for example, approximately 0.04 mm.

[0048] FIG. 10 is a view taken along the arrow X in FIG. As shown in Figures 5, 6 and 10, a pair of press-fit protrusions 82a, 82b are formed on the outer surface 79d of the skirt portion 79 (the side surfaces of the tooth side surface covering portion 72, the flange side surface covering portion 73, and the core side surface covering portion 66 facing the stator core 20). The pair of press-fit protrusions 82a, 82b are arranged on both circumferential sides of the tooth covering portion 64. These press-fit protrusions 82a, 82b are used to press-fit and attach the first insulator 61 to the stator core 20. The press-fit protrusions 82a, 82b prevent the first insulator 61 from falling off from the stator core 20.

[0049] The pair of press-fit protrusions 82a, 82b are arranged at equal intervals in the circumferential direction, excluding the location corresponding to the specific tooth 22A (specific tooth covering portion 64A), every other tooth covering portion 64. In the first embodiment, there are six teeth 22 (tooth covering portions 64), and therefore the pair of press-fit protrusions 82a, 82b are arranged at locations corresponding to the three tooth covering portions 64 arranged at equal intervals in the circumferential direction, excluding the specific tooth covering portion 64A.

[0050] FIG. 11 is a perspective view of the second insulator 62. As shown in FIG. 5 and 11, the basic configuration of the second insulator 62 is symmetrical to the first insulator 61 about the axial center (vertical center) of the stator core 20. For this reason, in the following description, the same components of the second insulator 62 as those of the first insulator 61 are denoted by the same reference numerals as those of the first insulator 61, and description thereof will be omitted.

[0051] The difference between the first insulator 61 and the second insulator 62 is that the outer wall portion 67 of the first insulator 61 has a retraction slit 68 and a pull-out slit 69 formed therein, whereas the outer wall portion 83 of the second insulator 62 does not have the retraction slit 68 or the pull-out slit 69 formed therein. Furthermore, the tip end 79a of the skirt portion 79 of the second insulator 62 is formed to follow the inclination direction of the tip end 79a of the skirt portion 79 of the first insulator 61. Therefore, when the first insulator 61 and the second insulator 62 are attached to the stator core 20 from both axial sides, the gap S (see FIG. 5) between the tip end portions 79a of the skirt portions 79 that abut against each other becomes constant.

[0052] <Insulator action during resin molding> Next, the function of the insulator 26 (first insulator 61 and second insulator 62) during resin molding will be described with reference to FIG. FIG. 12 is an explanatory diagram comparing a mold 90 used when resin-molding the first insulator 61 and the second insulator 62 with a mold 290 of a comparative example.

[0053] A parting line PL is set on the skirt portion 79 of each insulator 61, 62, parallel to the tooth side surface covering portion 72 and the flange side surface covering portion 73. Therefore, as shown in Fig. 12, the parting line PL is perpendicular to the clamping and release direction Y1 of an upper mold 91 and a lower mold 92 in a mold 90. Therefore, when the mold 90 is clamped, no force is applied to the upper mold 91 or the lower mold 92 in a direction perpendicular to the clamping and release direction Y1, preventing misalignment of the upper mold 91 or the lower mold 92. This improves the resin molding accuracy of the insulator 26.

[0054] In contrast, for example, if the parting line PL is set on the skirt portion 79 of each insulator 61, 62 so as to follow the leading end portion 79a, as in the mold 290 of the comparative example, the parting line PL will be oblique and not perpendicular to the clamping / release direction Y21 of the upper mold 291 and the lower mold 292. Therefore, when the mold 290 is clamped, a force is applied to the upper mold 291 or the lower mold 292 in a direction perpendicular to the clamping / release direction Y21, which may cause the upper mold 291 or the lower mold 292 to become misaligned. This reduces the resin molding accuracy of the insulator 26.

[0055] Incidentally, when measuring the molding accuracy of the insulator 26, it is particularly difficult to measure the skirt portion 79 because the tip end portion 79a is formed at an angle. That is, when measuring the skirt portion 79, the reference position is, for example, the lower surface 65a of the core end surface covering portion 65. In this case, it is easy to identify the tip end of the skirt portion 79 protruding from the lower surface 65a, but it is difficult to identify the point where the protruding height of the skirt portion 79 is lowest.

[0056] A more specific description will be given with reference to the enlarged portion of Figure 6. The enlarged portion of Figure 6 is shown as viewed from a direction perpendicular to the axial direction, and the scale has been changed appropriately, for ease of understanding. For example, when measuring the skirt portion 79 using a three-dimensional measuring machine m or the like with the lower surface 65a of the core end surface covering portion 65 as a reference, it is easy to abut the probe Pr against the very tip of the skirt portion 79. However, because the probe Pr is spherical, the probe Pr abuts against a slightly inclined portion above the point where the skirt portion 79 protrudes the least (see abutment point Pj in FIG. 6 ), which interferes with the abutment of the probe Pr against the point where the skirt portion 79 protrudes the least. This makes it difficult to reliably abut the probe Pr against the point where the skirt portion 79 protrudes the least.

[0057] In the first embodiment, a flat portion 79b is formed at the tip end 79a of the skirt portion 79 where the protrusion height is the smallest. This makes it easy to identify the point where the protrusion height of the skirt portion 79 is the smallest. Furthermore, when measuring the skirt portion 79 using, for example, a three-dimensional measuring machine m or the like with the lower surface 65a of the core end surface cover portion 65 as a reference, the probe Pr can be reliably brought into contact with the point where the protrusion height of the skirt portion 79 is the smallest. This allows the insulator 26 to be measured with high accuracy.

[0058] <Insulator assembly and its function during assembly> Next, the function of the insulator 26 during assembly will be described with reference to FIGS. 13 is a plan view, viewed from the axial direction, of a jig 93 used when assembling the first insulator 61, of the insulators 26, to the stator core 20. The second insulator 62 is assembled to the stator core 20 in the same manner as the first insulator 61 using the same jig 93, and therefore a description thereof will be omitted.

[0059] 6 and 13, when assembling the first insulator 61 to the stator core 20, the skirt portion 79 of the first insulator 61 faces downward (toward the stator core 20) above the axial direction of the stator core 20. In this state, the outer wall portion 67 of the first insulator 61 is pressed from above the first insulator 61 by a jig 93.

[0060] The jig 93 is formed in a cylindrical shape to correspond to the shape of the first insulator 61. The outer diameter of the jig 93 is slightly larger than the outer diameter of the core end surface covering portion 65 of the first insulator 61. The jig 93 has a chamfered flat portion 93a formed at a position corresponding to the coil lead-out portion 77 of the first insulator 61. This prevents the jig 93 from coming into contact with the coil lead-out portion 77 when pressing the first insulator 61, and allows the jig 93 to stably press the first insulator 61.

[0061] When the first insulator 61 is pressed by the jig 93, the skirt portion 79 is first inserted into the slot 27 of the stator core 20. At this time, because the tip portion 79a of the skirt portion 79 is formed at an angle, the tip portion 79a of the skirt portion 79 is not inserted into the slot 27 all at once. In other words, the skirt portion 79 is inserted into the slot 27 gradually, starting from the very tip of the skirt portion 79. Therefore, the tip portion 79a of the skirt portion 79 acts as a guide, allowing the skirt portion 79 to be smoothly inserted into the slot 27.

[0062] When the first insulator 61 is pressed by the jig 93, the outer surface 79d of the skirt portion 79 is fitted into the stator core 20. At this time, the first insulator 61 is press-fitted into the stator core 20 by the press-fit protrusions 82a, 82b formed on the skirt portion 79. Here, the jig 93 has a chamfered surface 93a formed at a position corresponding to the coil lead-out portion 77 of the first insulator 61. Therefore, the specific tooth covering portion 64A where the coil lead-out portion 77 is arranged and the periphery of this specific tooth covering portion 64A are not pressed by the jig 93.

[0063] Meanwhile, the press-fit protrusions 82a, 82b are arranged at equal intervals in the circumferential direction, every other tooth covering portion 64, except for the portion corresponding to the specific tooth covering portion 64A. Therefore, each press-fit protrusion 82a, 82b is pressed evenly. Furthermore, slight deformation of the first insulator 61 that occurs when the press-fit protrusions 82a, 82b are pressed into the stator core 20 is evenly distributed to the tooth covering portions 64 where the press-fit protrusions 82a, 82b are not formed and the periphery of these tooth covering portions 64. As a result, the first insulator 61 is reliably press-fitted and attached to the stator core 20.

[0064] <Coil winding method and detailed positions of lead-in slits and lead-out slits> Next, based on Figures 4 and 14 to 19, we will explain the winding method of the coil 24 that is wound from above the insulator 26 attached to the stator core 20, and the detailed positions of the pull-in slit 68 and pull-out slit 69 formed in the first insulator 61 of the insulators 26.

[0065] 4, the coil 24 is wound around each tooth 22 from above the insulators 61, 62 by a so-called concentrated winding method. More specifically, the coil 24 of each phase is wound continuously around the tooth 22 of the corresponding phase while being routed around the core end surface covering portion 65 of the first insulator 61. That is, for example, since the electric motor 2 of the first embodiment has a three-phase structure, the teeth 22 of the same phase are arranged circumferentially every two teeth 22. For example, since there are six teeth 22 in the first embodiment, the coils 24 of each phase are wound continuously around two teeth 22 while being routed around the core end surface covering portion 65 of the first insulator 61.

[0066] At this time, the coil 24 routed on the core end surface covering portion 65 of the first insulator 61 is drawn into the tooth covering portion 64 side through the drawing slit 68 of the first insulator 61. Then, the coil 24 is wound around the teeth 22 from above the tooth covering portion 64. Thereafter, the coil 24 wound around the tooth covering portion 64 (tooth 22) is drawn out onto the core end surface covering portion 65 again through the drawing slit 69 of the first insulator 61. Then, the coil 24 is guided to the terminal 86 of the terminal holder 85 through the coil guide recess 78 and connected to this terminal 86.

[0067] The coil 24 drawn into the lead-in slit 68 may be routed over the core end surface covering portion 65 so as to straddle the base of the corresponding tooth covering portion 64 (tooth 22) (routed counterclockwise in FIG. 4). After this, the coil 24 may be drawn into the tooth covering portion 64 side through the lead-in slit 68. Hereinafter, this case will be referred to as a case where the coil 24 is routed counterclockwise in CCW.

[0068] Furthermore, the coil 24 drawn into the lead-in slit 68 may be routed on the core end surface cover 65 from the opposite direction to the corresponding tooth cover 64 (tooth 22) (routed clockwise CW in FIG. 4). After this, the coil 24 may be drawn toward the tooth cover 64 through the lead-in slit 68. Hereinafter, this case will be referred to as a case where the coil 24 is routed clockwise CW.

[0069] Next, the detailed position of the lead-in slit 68 will be described with reference to FIGS. Fig. 14 is a plan view of the first insulator 61 as viewed from the axial direction, showing the state in which the coil 24 is drawn into the lead-in slit 68 when the coil 24 is routed clockwise (CW). Fig. 15 is a perspective view of the first insulator 61, showing the state in which the coil 24 is drawn into the lead-in slit 68 when the coil 24 is routed clockwise (CW). Fig. 16 is a plan view of the first insulator 61 as viewed from the axial direction, showing the state in which the coil 24 is drawn into the lead-in slit 68 when the coil 24 is routed counterclockwise (CCW). Fig. 17 is a perspective view of the first insulator 61, showing the state in which the coil 24 is drawn into the lead-in slit 68 when the coil 24 is routed counterclockwise (CCW).

[0070] 14 to 17, when viewed in the axial direction, the lead-in slit 68 is arranged on a side surface covering line L that passes through the tooth side surface covering portion 72 of the corresponding tooth covering portion 64. More specifically, when viewed in the axial direction, the first side edge 68a and the second side edge 68b that face each other in the circumferential direction of the lead-in slit 68 are arranged on both sides of the side surface covering line L. Here, the position of the lead-in slit 68 varies slightly depending on the direction in which the coil 24 is drawn into the lead-in slit 68 .

[0071] As shown in FIG. 14, the pull-in slit 68 into which the coil 24 routed clockwise (CW) is pulled is positioned so that the width W1 between the side covering portion straight line L and the first side edge 68a is smaller than the wire diameter D of the coil 24 when viewed from the axial direction. 14 and 15, the coil 24, which has been routed clockwise (CW), is pulled into the tooth covering portion 64 through the pull-in slit 68, and then turns back slightly before being wound onto the tooth covering portion 64 along the tooth side surface covering portion 72 on the side surface covering straight line L. This causes the coil 24 to be tightly wound onto the tooth covering portion 64 at the base of the tooth 22. Gaps between the tooth covering portion 64 and the coil 24 are minimized.

[0072] As shown in Figure 16, the pull-in slit 68 into which the coil 24 pulled counterclockwise (CCW) is pulled is positioned so that the width W2 between the side covering portion straight line L and the second side edge 68b is larger than the wire diameter D of the coil 24 when viewed from the axial direction. 16 and 17, the coil 24, which has been routed counterclockwise (CCW), is drawn into the tooth covering portion 64 through the drawing-in slit 68, and then is wound onto the tooth covering portion 64 while riding up the tooth end face covering portion 71 and following the tooth side face covering portion 72 on the side face covering straight line L. As a result, the coil 24 is wound tightly on the tooth covering portion 64 at the base of the tooth 22. Gaps between the tooth covering portion 64 and the coil 24 are minimized.

[0073] Next, the detailed position of the extraction slit 69 will be described with reference to FIGS. Fig. 18 is a plan view of the first insulator 61 as viewed from the axial direction, illustrating a state in which the coil 24 routed in a clockwise direction (CW) is drawn into the tooth covering portion 64 through the lead-in slit 68 and then drawn out through the draw-out slit 69. Fig. 19 is a plan view of the first insulator 61 as viewed from the axial direction, illustrating a state in which the coil 24 routed in a counterclockwise direction (CCW) is drawn into the tooth covering portion 64 through the lead-in slit 68 and then drawn out through the draw-out slit 69.

[0074] As shown in FIG. 18, the coil 24 is pulled clockwise (CW) and wound through the lead-in slit 68, and then pulled out radially outward through the pull-out slit 69, and then pulled clockwise again. As shown in FIG. 19, the coil 24 is pulled counterclockwise (CCW) and wound through the pull-in slit 68, and then pulled out radially outward through the pull-out slit 69, and then pulled counterclockwise again.

[0075] 18 and 19, the position of the lead-out slit 69 does not change whether the coil 24 is routed clockwise (CW) or counterclockwise (CCW). That is, the lead-out slit 69 is located on the opposite side of the lead-in slit 68 across the circumferential center C2 of the tooth covering portion 64 (the tooth main body 28 of the tooth 22). The lead-out slit 69 is located in a region Ar between a first line Ld1 passing through the circumferential center C2 of the tooth covering portion 64 and the rotation axis C1, and a second line Ld2 passing through the circumferential end of the flange portion 29 of the tooth 22 and the rotation axis C1. Therefore, when the coil 24 wound around the tooth 22 is routed radially outward through the lead-out slit 69, there is no significant gap between the routed coil 24 and the wound coil 24.

[0076] <Coil winding state and effect of the inclined part> Next, the winding state of the coil 24 and the function of the inclined portions 75 of the insulators 61 and 62 will be described with reference to FIGS. 20, 21A, and 21B. Fig. 20 is an explanatory diagram showing the state in which coil 24 is wound on insulator 26. Fig. 20 corresponds to a plan view of first insulator 61 viewed from above. Fig. 21A is an explanatory diagram of the inclination angle of inclined portion 75. Fig. 21B is an explanatory diagram of the inclination angle of a comparative example. As shown in FIG. 20, the coil 24 is wound spirally from the base side of the tooth 22 (tooth covering portion 64) toward the inside in the radial direction.

[0077] 21A, the inclined portions 75 formed on the tooth end surface covering portions 71 cause the coils 24 to slide down toward the bases of the teeth 22 (see arrow Y1 in FIG. 21A). That is, the coils 24 are wound while being compressed toward the bases of the teeth 22. This prevents unnecessary gaps from being formed between the wound coils 24.

[0078] Furthermore, the pin abutment recess 76 used when resin-molding the insulator 26 has a center 76c of the pin abutment recess 76 located radially inward relative to the radial center 75c of the inclined portion 75. The pin abutment recess 76 is also formed to fit on the inclined portion 75. Because the pin abutment recess 76 is located radially inward, its diameter is smaller than when it is located radially outward. As a result, the coil 24 slides down more smoothly along the inclined portion 75 toward the base of the tooth 22 than when the center 76c of the pin abutment recess 76 is located radially outward relative to the radial center 75c of the inclined portion 75.

[0079] Here, the inclination angle θ1 of the inclined portion 75 is smaller than 45°. Also, an inclined line Lk is inclined at 45° with respect to a vertical line Ls that is parallel to the rotation axis C1 and passes through the center of the coil 24. The contact point Sp of the coil 24 wound later (hereinafter referred to as the "following coil 24") with the coil 24 wound earlier (hereinafter referred to as the "following coil 24") is located axially inward of the inclined line Lk of the preceding coil 24. Therefore, the following coil 24 does not ride over the preceding coil 24.

[0080] 21B, if the inclination angle θ1' of the inclined portion 75 is greater than 45°, the contact point Sp' of the trailing coil 24 with the leading coil 24 is located on the inclined straight line Lk of the leading coil 24 or axially outward of the inclined straight line Lk. This means that the trailing coil 24 may ride up on the leading coil 24. Therefore, by making the inclination angle θ1 of the inclined portion 75 less than 45°, the wound coil 24 is prevented from becoming unwound.

[0081] With this configuration, when power is supplied to each coil 24 via the controller 4, a magnetic flux linkage is formed in the stator core 20. Magnetic attractive and repulsive forces are generated between this magnetic flux linkage and a magnet (not shown) of the rotor 9, causing the rotor 9 to rotate continuously. When the rotor 9 rotates, the worm shaft 44, which is integrated with the shaft 31, rotates. Furthermore, the worm wheel 45, which meshes with the worm shaft 44, rotates. The rotation of the worm wheel 45 is transmitted to the output shaft 48, which is connected to the worm wheel 45. As a result, desired electrical equipment connected to the output shaft 48 is driven.

[0082] As described above, in the first embodiment, the inclined portions 75 are formed on the front surface 71a of the tooth end surface covering portion 71 of each insulator 61, 62. The inclined portions 75 are inclined so that their height from the axial end face of the tooth body 28 gradually decreases radially outward. Furthermore, the back surface 71b of the tooth end surface covering portion 71 is formed with an inclined portion parallel portion 95 and a tooth parallel portion 96. Because the inclined portion parallel portion 95 is formed parallel to the inclined portion 75, the thickness T1 of the tooth end surface covering portion 71 is constant in the region where the inclined portion parallel portion 95 is located. Furthermore, because the tooth parallel portion 96 is formed parallel to the pin abutment recess 76, the thickness T3 of the tooth end surface covering portion 71 is constant in the region where the pin abutment recess 76 is located. Therefore, even if the height of the inclined portions 75 from the axial end faces of the tooth bodies 28 gradually decreases radially outward, and the pin abutment recesses 76 are formed parallel to the upper ends of the tooth bodies 28, the thickness of the tooth end face covering portions 71 can be kept constant over most of the tooth. This means that an increase in thickness at the inclined portions 75 of the insulators 61, 62 can be prevented. As a result, deterioration of moldability due to heat sink and the like can be suppressed when the insulators 61, 62 are resin-molded. This improves the resin-molding precision of the insulators 61, 62.

[0083] Since the resin molding precision of each insulator 61, 62 can be improved, it will be possible to contribute to Goal 12 of the United Nations-led Sustainable Development Goals (SDGs), which is to "ensure sustainable consumption and production patterns."

[0084] The teeth 22 protrude radially from the inner peripheral surface of the core body 21. In contrast, the inclined portions 75 are inclined so that their height from the axial end face of the tooth body 28 gradually decreases radially outward. The coils 24 are wound from above the insulators 26 starting from the base of the teeth 22. This allows the coils 24 to be wound while being packed tightly together toward the base of the teeth 22. This prevents unnecessary gaps from being formed between the wound coils 24. This reliably improves the space factor of the coils 24.

[0085] The inclination angle θ1 of the inclined portion 75 is smaller than 45°. Therefore, the contact point Sp of the trailing coil 24 with the leading coil 24 can be positioned axially inward of the inclined straight line Lk of the leading coil 24. This prevents the trailing coil 24 from riding over the leading coil 24, and prevents the coil 24 from becoming unwound.

[0086] The tip portions 79a of the skirt portions 79 formed on each of the insulators 61, 62 are formed obliquely so that the height of their protrusion from the tooth end surface covering portions 71 and the core end surface covering portions 65 gradually changes along the circumferential direction. Therefore, when inserting the skirt portions 79 into the slots 27 of the stator core 20 (when attaching the insulators 61, 62 to the core body 21 and the teeth 22), the skirt portions 79 can be gradually inserted into the slots 27 starting from the very tip of the skirt portions 79. Therefore, the tip portions 79a of the skirt portions 79 act as a guide, making it easy to attach the insulators 61, 62 to the stator core 20.

[0087] Furthermore, a flat portion 79b parallel to the tooth end surface covering portion 71 and the core end surface covering portion 65 is formed at the point of the tip portion 79a of the skirt portion 79 where the protrusion height is the lowest. This makes it easy to identify the point where the protrusion height of the skirt portion 79 is the lowest. Furthermore, when measuring the skirt portion 79 using, for example, a three-dimensional measuring machine m or the like with the lower surface 65a of the core end surface covering portion 65 as a reference, the probe Pr can be reliably brought into contact with the point where the protrusion height of the skirt portion 79 is the lowest. Therefore, the insulator 26 can be measured with high accuracy.

[0088] While the tip end 79a of the skirt portion 79 is formed at an angle, the skirt portion 79 has a parting line PL that is parallel to the tooth side surface covering portion 72 and the flange side surface covering portion 73. This allows the parting line PL to be perpendicular to the clamping and release direction Y1 of the upper mold 91 and the lower mold 92 in the mold 90. Therefore, when the mold 90 is clamped, no force is applied to the upper mold 91 or the lower mold 92 in a direction perpendicular to the clamping and release direction Y1, preventing misalignment of the upper mold 91 or the lower mold 92. This improves the resin molding accuracy of the insulator 26.

[0089] Furthermore, recesses 81 are formed on the inner surface 79c of the skirt portion 79 (the side surfaces of the tooth side surface covering portion 72, the flange side surface covering portion 73, and the core side surface covering portion 66 opposite the stator core 20) from the parting line PL to the tip end 79a, with minute steps 80 interposed between them. Therefore, even if the parting line PL is set midway along the side surface of the resin molded product (skirt portion 79), the occurrence of burrs at this parting line PL during resin molding can be suppressed.

[0090] Coil lead-out portions 77 are integrally formed with the core end surface covering portion 65 and the outer wall portion 67, and are arranged collectively at the base of the specific tooth 22A (specific tooth covering portion 64A). A pair of press-fitting protrusions 82a, 82b for press-fitting the insulators 61, 62 into the stator core 20 are arranged at equal intervals in the circumferential direction every other tooth covering portion 64, except for the portion corresponding to the specific tooth 22A (specific tooth covering portion 64A). By forming the press-fit protrusions 82a, 82b, the insulators 61, 62 are press-fit when attached to the stator core 20 (core body 21). This makes it difficult for the insulators 61, 62 to come off from the stator core 20.

[0091] Moreover, since a pair of press-fit protrusions 82a, 82b is disposed at equal intervals in the circumferential direction for every other tooth covering portion 64, each of the press-fit protrusions 82a, 82b can be pressed evenly by the jig 93. Furthermore, slight deformation of the first insulator 61 that occurs when the press-fit protrusions 82a, 82b are pressed into the stator core 20 (core body 21) can be evenly distributed to the tooth covering portion 64 where the press-fit protrusions 82a, 82b are not formed and the periphery of this tooth covering portion 64. As a result, irregular deformation of each insulator 61, 62 can be suppressed.

[0092] Moreover, when pressing the insulators 61, 62 using, for example, a jig 93, the pressing is performed by the jig 93 while avoiding the coil lead-out portion 77, which is a portion of the irregular shape (see FIG. 13). Therefore, by forming the press-fit protrusions 82a, 82b while avoiding the specific tooth 22A on which the coil lead-out portion 77 is arranged, the press-fit protrusions 82a, 82b can be pressed evenly by the jig 93. This allows the insulators 61, 62 to be reliably attached to the stator core 20 (core body 21).

[0093] The pin abutment recess 76 used when resin-molding the insulator 26 has a center 76c of the pin abutment recess 76 located radially inward relative to the radial center 75c of the inclined portion 75. The pin abutment recess 76 is also formed to fit on the inclined portion 75. Because the pin abutment recess 76 is located radially inward, its diameter is smaller than when it is located radially outward. As a result, the coil 24 slides smoothly along the inclined portion 75 toward the base of the tooth 22 compared to when the center 76c of the pin abutment recess 76 is located radially outward relative to the radial center 75c of the inclined portion 75. In other words, when the coil 24 is shifted in one direction along the inclined portion 75, the pin abutment recess 76 is prevented from interfering with the movement of the coil 24. This allows the coil 24 to be positioned on the inclined portion 75 without any gaps.

[0094] The lead-in slit 68, into which the coil 24 is drawn clockwise (CW), is positioned so that the width W1 between the side surface covering line L and the first side edge 68a is smaller than the wire diameter D of the coil 24 when viewed in the axial direction. Therefore, after the coil 24 is drawn toward the tooth covering portion 64 through the lead-in slit 68, it is wound onto the tooth covering portion 64, slightly turning back along the tooth side surface covering portion 72 on the side surface covering line L. This allows the coil 24 to be tightly wound on the tooth covering portion 64 at the base of the tooth 22. This minimizes gaps between the tooth covering portion 64 and the coil 24. This ensures that the insulator 26 and the coil 24 are in close contact with each other at the base of the tooth 22, improving the space factor of the coil 24.

[0095] The lead-in slit 68, into which the coil 24 is drawn counterclockwise (CCW), is positioned so that the width W2 between the side surface covering line L and the second side edge 68b is greater than the wire diameter D of the coil 24 when viewed in the axial direction. Therefore, the coil 24, which is drawn counterclockwise (CCW), is drawn into the tooth covering portion 64 through the lead-in slit 68, and then rides over the tooth end surface covering portion 71 and is wound further onto the tooth covering portion 64, following the tooth side surface covering portion 72 on the side surface covering line L. This allows the coil 24 to be tightly wound on the tooth covering portion 64 at the base of the tooth 22. This minimizes the occurrence of gaps between the tooth covering portion 64 and the coil 24. This ensures that the insulator 26 and the coil 24 are in close contact with each other at the base of the tooth 22, improving the space factor of the coil 24.

[0096] The draw-out slits 69 are disposed in an area Ar between a first straight line Ld1 passing through the circumferential center C2 of the tooth covering portion 64 and the rotation axis C1, and a second straight line Ld2 passing through the circumferential end of the flange portion 29 of the tooth 22 and the rotation axis C1. Therefore, when the coil 24 wound around the tooth 22 is drawn out radially outward through the draw-out slits 69, it is possible to prevent a large gap between the drawn-out coil 24 and the wound coil 24. This makes it possible to reliably tighten the coil 24 wound around the tooth 22 and improve the space factor of the coil 24.

[0097] By improving the space factor of the coil 24, the torque performance of the electric motor 2 can be improved. This makes it possible to reduce the energy consumption when driving the electric motor 2. This makes it possible to contribute to Goal 7 of the Sustainable Development Goals (SDGs) led by the United Nations, which is to "Ensure access to affordable, reliable, sustainable and modern energy for all."

[0098] [Second embodiment] Next, a second embodiment of the present invention will be described with reference to Figures 22 and 23. The same aspects as those in the first embodiment will be described with the same reference numerals. Fig. 22 is a plan view of a tooth covering portion 264 of a first insulator 261 in the second embodiment as viewed from the axial direction. Fig. 23 is a cross-sectional view taken along line XXIII-XXIII in Fig. 22.

[0099] In this second embodiment, the stator 8 has a cylindrical stator core 20 whose central axis coincides with the rotation axis C1, an insulator 26 attached to the stator core 20, and a plurality of coils 24 having a three-phase (U phase, V phase, W phase) structure wound around the stator core 20 from above the insulator 26, and the insulator 26 has a first insulator 261 attached to one axial side of the stator core 20 and a second insulator 62 attached to the other axial side of the stator core 20, and the basic configuration is the same as that of the first embodiment described above.

[0100] As in the first embodiment described above, the basic configuration of the second insulator 62 in the second embodiment is symmetrical to the first insulator 261 about the axial center (vertical center) of the stator core 20. For this reason, the second insulator 62 in the second embodiment is denoted by the same reference numeral as in the first embodiment described above, and a description thereof will be omitted.

[0101] As shown in Figures 22 and 23, the difference between the first embodiment and the second embodiment is that the shape of the tooth end face covering portion 71 in the first embodiment is different from the shape of the tooth end face covering portion 271 in the second embodiment. More specifically, the surface 271a of the tooth end face covering portion 271 in the second embodiment is provided with an inclined portion 275a formed radially outward from a radial center 271c of the tooth end face covering portion 271, and a non-inclined portion 275b formed radially inward from the radial center 271c of the tooth end face covering portion 271. The inclined portion 275a is inclined so that its height from the axial end face of the tooth main body 28 gradually decreases radially outward. The non-inclined portion 275b is formed parallel to the axial end face of the tooth main body 28.

[0102] Furthermore, a pin abutment recess 276 is formed on a surface 271a of the tooth end surface covering portion 271. The pin abutment recess 276 is a location that comes into contact with an ejector pin of a resin molding machine (not shown) when the first insulator 61 is molded from resin. A center 276c of the pin abutment recess 276 is located slightly radially outward from the radial center 271c of the tooth end surface covering portion 271. The diameter of the pin abutment recess 276 is larger than the diameter of the pin abutment recess 76 of the first embodiment.

[0103] Additionally, a back surface 271b of the tooth end face covering portion 271 facing the tooth main body 28 is provided with an inclined-parallel portion 295 formed to correspond to the shape of the inclined portion 275a, a tooth parallel portion 296 formed parallel to the axial end face of the tooth main body 28, and an abutting portion 297 abutting against the axial end face of the tooth main body 28. Therefore, the thickness T4 of the inclined portion 275a, the thickness T5 of the non-inclined portion 275b, and the thickness T6 of the pin abutting recess 276 are all constant. Furthermore, the overall thickness of the tooth end face covering portion 271 is constant. The inclination angle θ2 of the inclined portion 275a is smaller than 45°.

[0104] Therefore, according to the second embodiment, the inclined portion 275a has the same effect as the first embodiment. Also, since the overall thickness of the tooth end face covering portion 271 is constant, deterioration of moldability due to heat sink or the like can be suppressed when the insulators 261, 62 are resin-molded. This improves the resin-molding accuracy of the insulators 261, 62.

[0105] The present invention is not limited to the above-described embodiment, but includes various modifications to the above-described embodiment without departing from the spirit of the present invention. For example, in the above embodiment, the reduction geared motor 1 has been described as being used as a drive source for a wiper device of a vehicle. However, the reduction geared motor 1 is not limited to this, and can be applied to various drive devices. Furthermore, only the electric motor 2 having the above-described configuration of the reduction geared motor 1 may be used in various electrical devices.

[0106] In the second embodiment described above, the non-inclined portion 275b is formed parallel to the axial end surface of the tooth main body 28. However, this is not limiting, and the non-inclined portion 275b may be formed so as to be inclined at an angle smaller than the inclination angle θ2 of the inclined portion 275a.

[0107] In the above-described embodiment, the inclined portions 75, 275a are inclined so that their height from the axial end face of the tooth main body 28 gradually decreases radially outward. However, this is not limited to this, and the inclination direction of the inclined portions 75, 275a may be changed depending on the protruding direction of the teeth 22. In other words, when the teeth 22 protrude radially outward, the bases of the teeth 22 are located radially inward relative to the tips of the teeth 22. In such a case, the height of the inclined portions 75, 275a from the axial end face of the tooth main body 28 may be inclined so that it gradually decreases radially inward.

[0108] In the above embodiment, the coil 24 of the stator 8 has a three-phase (U-phase, V-phase, W-phase) structure. However, the number of phases of the coil 24 is not limited to three. [Explanation of symbols]

[0109] DESCRIPTION OF SYMBOLS 1...motor with reducer, 2...electric motor, 3...reduction section, 4...controller, 5...motor case, 6...first motor case, 6a, 7a...opening, 7...second motor case, 8...stator, 9...rotor, 10...bottom, 10a...through hole, 11...connector, 16...outer flange section, 17...outer flange section, 20...stator core, 20p...electromagnetic steel plate, 21...core body, 22...teeth, 22A...specific teeth, 23...fixing section, 23a...bolt insertion hole, 24...coil, 24a...terminal section, 25...bolt, 26...insulator, 27...slot, 28...teeth body, 28a ...tooth tip portion, 29... flange portion, 31... shaft, 32... rotor core, 32a... magnet cover, 40... gear case, 40a... opening, 40b... side wall, 40c... bottom wall, 41... worm reduction mechanism, 42... gear accommodating portion, 43... opening, 44... worm shaft, 45... worm wheel, 46, 47... bearing, 48... output shaft, 48a... spline, 49... bearing boss, 50... magnetic detection element, 51... controller board, 52... rib, 53... cover, 61, 261... first insulator, 62... second insulator, 63... core body covering portion, 64... tooth covering portion, 64 A...specific tooth covering portion, 65...core end surface covering portion, 65a...lower surface, 65b...upper surface, 66...core side surface covering portion, 67...outer wall portion, 68...pull-in slit, 68a...first side edge, 68b...second side edge, 69...draw-out slit, 71, 271...teeth end surface covering portion, 71a, 271a...surface, 71b, 271b...back surface, 271c...radial center of tooth end surface covering portion, 72...teeth side surface covering portion, 73...flange side surface covering portion, 74...inner wall portion, 75, 275a...inclined portion, 275b...non-inclined portion, 75c...radial center of inclined portion, 76...pin abutting recess (recess), 76c, 276c... Center of pin abutment recess, 77... coil pull-out portion, 78... coil guide recess, 78a... coil holding claw, 79... skirt portion, 79a... tip portion (skirt tip portion), 79b... flat portion, 79c... inner surface, 79d... outer surface, 80... minute step portion, 81... recess, 82a, 82b... press-fit protrusion, 83... outer wall portion, 85... terminal holder, 86... terminal, 87... holder body, 87a... terminal storage recess, 88... cover portion, 88a... end face cover portion, 88b... outer periphery cover portion, 88c... cut-out portion, 90, 290... mold, 91, 291... upper mold, 92, 292... lower mold, 93... jig, 93a... flat chamfered portion, 95,295...Inclined parallel portion (recessed portion), 96, 296...Teeth parallel portion (recessed portion), 97, 297...Abutment portion, Ar...Area, D...Wire diameter, T1, T2, T3, T4, T5, T6...Thickness, W1, W2...Width, θ1, θ2...Inclination angle,

Claims

1. an insulator attached to an annular core body and a plurality of teeth protruding from the core body in a radial direction, for insulating the teeth from coils wound around the teeth; an annular core body to which the insulator is attached, and the teeth protruding radially inward from an inner circumferential surface of the core body; the coil being routed along the core body and wound around the teeth via the insulator; Equipped with The insulator is a tooth end surface covering portion that covers an axial end surface of the tooth; a tooth side surface covering portion that covers a circumferential side surface of the tooth body extending along a radial direction of the tooth; an outer wall portion formed to protrude along an axial direction from a radially outer end of the tooth end surface covering portion; an inner wall portion formed to protrude along an axial direction from a radially inner end of the tooth end surface covering portion; and the outer wall portion has a pull-in slit formed for each of the teeth, for pulling the coil from a radially outer side to a radially inner side of the outer wall portion, The lead-in slit is a first lead-in slit through which the coil is drawn so as to straddle the root of the corresponding tooth, and into which the coil is drawn; a second lead-in slit through which the coil is drawn in a direction opposite to the corresponding tooth; and In each of the first retracting slit and the second retracting slit, a first side edge and a second side edge that face each other in the circumferential direction are arranged on both sides of a side surface covering portion straight line that passes through an outer surface of the tooth side surface covering portion when viewed in the axial direction, the second side edge is disposed closer to a circumferential center of the tooth than the first side edge is, At a location where the coil is drawn into the first draw-in slit, a width between the side covering portion straight line in the first draw-in slit and the second side edge in the first draw-in slit as viewed in the axial direction is larger than a wire diameter of the coil, At a location where the coil is drawn into the second draw-in slit, a width between the side covering portion straight line in the second draw-in slit and the first side edge in the second draw-in slit as viewed in the axial direction is smaller than a wire diameter of the coil. A stator characterized by:

2. The teeth are The tooth body; a flange portion integrally formed with a tip end portion of the tooth body on the opposite side of the core body and extending in a circumferential direction; and the outer wall portion has a pull-out slit formed for each of the teeth, for pulling out the coil from a radially inner side to a radially outer side of the outer wall portion, The pull-out slits are arranged on the opposite side of the circumferential center of the corresponding tooth body from the pull-in slits, and are arranged in a region between a first line passing through the circumferential center of the tooth body and the central axis of the core body, and a second line passing through the circumferential end of the flange portion and the central axis of the core body.

2. The stator according to claim 1.

3. The stator according to claim 1 or 2; a rotor rotatably disposed radially inside the stator; An electric motor characterized by:

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