electric motor

Abstract

To attach a stator to a proper position.SOLUTION: An electric motor 10 in one embodiment has a base member 12 which comprises a baseplate 30 including a shaft holder 21 rotatably supporting a rotor 15 and support walls 31, 32 extending in a direction crossing the baseplate 30 from the baseplate 30. The electric motor 10 has a stator 20 which comprises a stator core 55 arranged inside the support walls 31, 32 and a stator coil 57 wound around the stator core 55. A plurality of protrusions 41a, 42a, 43a are formed with unequally spaces in a circumferential direction on an outer peripheral surface 55a of the stator core 55. A plurality of concavities 41b, 42b, 43b are formed with unequally spaces in the circumferential direction on inner peripheral surfaces 31a, 32a of the support walls 31, 32. The plurality of protrusions 41a, 42a, 43a and the plurality of concavities 41b, 42b, 43b are engaged with each other.SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

[0002] An electric motor has a rotor and a stator. As a stator mounting structure for such an electric motor, a structure has been proposed in which the stator is mounted to a base by engaging a protrusion on the base with a through-hole in the stator (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-19392 Summary of the Invention [Problem to be solved by the invention]

[0004] In order to improve the performance of an electric motor, it is important to fix the stator in an appropriate position within the housing. In other words, it is required to mount the stator in an appropriate position in an electric motor.

[0005] The object of the present invention is to mount the stator in the proper position. [Means for solving the problem]

[0006] An electric motor according to one embodiment is an electric motor having a rotor, the electric motor including: a disk portion having a bearing portion that rotatably supports the rotor; and a support wall portion extending from the disk portion in a direction intersecting the disk portion. It is a sheet metal part Base material The electric motor has a stator core disposed inside the support wall portion; and a stator coil wound around the stator core. It has.A plurality of protrusions are formed on the outer peripheral surface of the stator core at uneven intervals in the circumferential direction, and a plurality of recesses are formed on the inner peripheral surface of the support wall portion at uneven intervals in the circumferential direction, and the plurality of protrusions and the plurality of recesses engage with each other. The recess formed in the support wall portion is a notch that penetrates the support wall portion in the thickness direction and opens to the edge of the support wall portion. [Effects of the Invention]

[0007] According to one aspect of the present invention, a plurality of protrusions are formed at irregular intervals in the circumferential direction on the outer peripheral surface of the stator core, and a plurality of recesses are formed at irregular intervals in the circumferential direction on the inner peripheral surface of the support wall, and the plurality of protrusions and the plurality of recesses are engaged with each other, thereby enabling the stator to be mounted in an appropriate position. [Brief explanation of the drawings]

[0008] [Figure 1A] 1 is a perspective view showing an electric motor according to an embodiment; [Figure 1B] 1 is a perspective view showing an electric motor according to an embodiment; [Figure 2] FIG. 2 is an exploded perspective view showing the internal structure of the electric motor. [Figure 3] FIG. 1B is a cross-sectional view taken along line AA in FIG. 1A. [Figure 4A] 10A and 10B are perspective views showing a process of attaching the stator to the base member. [Figure 4B] FIG. 2 is a perspective view showing a state in which a stator is attached to a base member. [Figure 5A] 10A and 10B are perspective views showing a process of attaching the stator to the base member. [Figure 5B] FIG. 2 is a perspective view showing a state in which a stator is attached to a base member. [Figure 6] 10A and 10B are diagrams illustrating an example of a protrusion formed on a stator and a recess formed on a base member. [Figure 7] 4A and 4B are diagrams illustrating the positional relationship between a base member and a flexible printed circuit board. [Figure 8] 10A and 10B are diagrams illustrating an example of a protrusion formed on a stator core and a recess formed on a base member. [Figure 9]10A and 10B are diagrams illustrating an example of a protrusion formed on a stator core and a recess formed on a base member. [Figure 10] FIG. 2 is a perspective view showing an example of a stator core and a base member. DETAILED DESCRIPTION OF THE INVENTION

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the accompanying drawings. In the following description, identical or substantially identical configurations and elements are designated by the same reference numerals and will not be described repeatedly.

[0010] [Overall structure of electric motor] 1A and 1B are perspective views showing an electric motor 10 according to one embodiment of the present invention. Note that the electric motor 10 in FIG. 1A is shown from the cover member 11 side, while the electric motor 10 in FIG. 1B is shown from the base member 12 side. As shown in FIGS. 1A and 1B, the electric motor 10 has a housing 13 formed by the cover member 11 and the base member 12. The electric motor 10 is also provided with a flexible printed circuit board 14, which protrudes to the outside from the gap between the cover member 11 and the base member 12. Furthermore, as shown in FIG. 1B, a pinion 17 is located approximately in the center of the base member 12. The pinion 17 is fixed to the tip of a shaft 16 (hereinafter referred to as the rotor shaft 16) provided on the rotor 15. In this specification, the direction along the central axis Ca of the rotor 15 and the direction parallel to the central axis Ca are defined as the up-down direction. For convenience, the cover member 11 side will be referred to as the upside, and the base member 12 side will be referred to as the downside.

[0011] Fig. 2 is an exploded perspective view showing the internal structure of electric motor 10, and Fig. 3 is a cross-sectional view taken along line AA in Fig. 1A. As shown in Figs. 2 and 3, electric motor 10 includes a housing 13 made up of a cover member 11 and a base member 12, an annular stator 20 attached to base member 12, and a rotor 15 rotatably supported by base member 12. A cylindrical shaft holder 21 that rotatably supports rotor shaft 16 is provided approximately in the center of base member 12. A spring washer 22 and a bearing 23 are inserted into one opening of shaft holder 21, and a bearing 24 is inserted into the other opening of shaft holder 21. Furthermore, rotor shaft 16 is inserted into bearings 23 and 24 housed within shaft holder 21, and a pinion 17 is press-fitted into the tip of rotor shaft 16 that protrudes from shaft holder 21. Furthermore, a flexible printed circuit board 14 having a Hall element 25 is provided between the base member 12 and the stator 20, and an insulating sheet 26 covering a part of the flexible printed circuit board 14 is also provided.

[0012] [housing] 2 and 3, the cover member 11 constituting the housing 13 has a disk-shaped cover main body 27 and a cover wall 28 provided on the outer edge of the cover main body 27 so as to surround the cover main body 27. The base member 12 constituting the housing 13 has the shaft holder (bearing portion) 21 described above and a disk-shaped base plate (disk portion) 30. The base member 12 constituting the housing 13 also has two support walls (support wall portions) 31 and 32 bent at a substantially right angle at the outer edge 30a of the base plate 30.

[0013] That is, the base member 12 has two support walls 31, 32 extending from the base plate 30 in a direction intersecting the base plate 30. In other words, the base member 12 has two support walls 31, 32 extending in a direction intersecting the surface of the base plate 30. One support wall 31 has one recess 41b formed therein, and the other support wall 32 has two recesses 42b, 43b formed therein. In this manner, a plurality of recesses 41b, 42b, 43b are formed at predetermined intervals in the circumferential direction on the inner circumferential surfaces 31a, 32a of the support walls 31, 32 that curve along the base plate 30. The recesses 41b, 42b, 43b formed in the support walls 31, 32 are notches that penetrate the support walls 31, 32 in the thickness direction and open to the upper ends (edges) 31b, 32b of the support walls 31, 32.

[0014] The base member 12 constituting the housing 13 is a sheet metal part manufactured by subjecting a metal plate to cutting, bending, and other processes. The base member 12, which is a sheet metal part, is provided with two mounting plates (mounting portions) 33, 34 extending radially outward from the outer edge 30a of the base plate 30. Each mounting plate 33, 34 is formed with a through-hole 35 for inserting a screw or the like, and the mounting plates 33, 34 can be used to secure the base member 12 to a device (not shown). The support walls 31, 32 provided on the base member 12 have a recessed engagement groove 36 formed at their lower ends. Furthermore, the cover wall 28 provided on the cover member 11 has an engagement claw 37 formed at its lower end that engages with the engagement groove 36 of the support walls 31, 32.

[0015] [Rotor and Stator] 2 and 3, the rotor 15 accommodated in the housing 13 has a rotor hub 50 to which the rotor shaft 16 is fixed, an annular rotor core 51 fixed to the outer peripheral surface of the rotor hub 50, and a plurality of permanent magnets 52 fixed to the outer peripheral surface of the rotor core 51. As described above, the rotor shaft 16 fixed to the rotor 15 is supported by the shaft holder 21 of the base member 12 via bearings 23 and 24. In other words, the rotor 15 is rotatably supported by the base plate 30 of the base member 12.

[0016] The stator 20 accommodated in the housing 13 includes a stator core 55 made of a plurality of laminated electromagnetic steel plates and a stator coil 57 wound around each tooth 56 of the stator core 55. Furthermore, a plurality of protrusions 41a, 42a, and 43a are formed on an outer peripheral surface 55a of the stator core 55 at predetermined intervals in the circumferential direction. Furthermore, the stator core 55 is coated with a paint made of an insulating material, except for the tip surfaces of the teeth 56 and the protrusions 41a, 42a, and 43a. Furthermore, as shown in FIG. 3 , an insulator 58 made of an insulating material is provided between the teeth 56 and the stator coil 57. In the illustrated example, the stator core 55 has twelve teeth 56 and slots 59, but the number of teeth 56 and slots 59 formed in the stator core 55 is not limited to this number, and the number of teeth 56 and slots 59 formed in the stator core 55 may be changed.

[0017] [Stator installation process] Fig. 4A is a perspective view showing the process of attaching stator 20 to base member 12, and Fig. 4B is a perspective view showing the state where stator 20 has been attached to base member 12. Fig. 5A is a perspective view showing the process of attaching stator 20 to base member 12, and Fig. 5B is a perspective view showing the state where stator 20 has been attached to base member 12. Note that Figs. 4A and 4B show base member 12 and stator 20 from the support wall 31 side, and Figs. 5A and 5B show base member 12 and stator 20 from the support wall 32 side.

[0018] 4A and 5A , when attaching the stator 20 to the base member 12, the stator 20 is moved toward the base member 12 while positioning the protrusions 41a, 42a, and 43a of the stator 20 relative to the recesses 41b, 42b, and 43b of the base member 12. As a result, the stator core 55 of the stator 20 is disposed inside the support walls 31 and 32 of the base member 12, i.e., radially inside. That is, the protrusions 41a, 42a, and 43a of the stator 20 are inserted into the recesses 41b, 42b, and 43b of the base member 12, and the stator 20 is attached to the base member 12. In other words, the protrusions 41a of the stator 20 engage with the recesses 41b of the base member 12, the protrusions 42a of the stator 20 engage with the recesses 42b of the base member 12, and the protrusions 43a of the stator 20 engage with the recesses 43b of the base member 12.

[0019] When attaching the stator 20 to the base member 12, an adhesive is applied between the base member 12 and the stator 20 to fix the base member 12 and the stator 20 to each other. That is, the base member 12 and the stator 20 are fixed to each other not only by engaging the protrusions 41a, 42a, 43a with the recesses 41b, 42b, 43b but also by using an adhesive. In this way, the base member 12 and the stator 20 are fixed to each other using an adhesive, but the method is not limited thereto, and the base member 12 and the stator 20 may be fixed to each other using a fastening member such as a screw.

[0020] [Positions of convex and concave parts] FIG. 6 is a diagram illustrating an example of protrusions 41a, 42a, and 43a formed on the stator 20 and recesses 41b, 42b, and 43b formed on the base member 12. First, the multiple protrusions 41a, 42a, and 43a formed on the stator 20 will be described. As shown in FIG. 6, a line that intersects perpendicularly with the central axis Ca and passes through the center c1a of the protrusion 41a is defined as "L1a." Furthermore, a line that intersects perpendicularly with the central axis Ca and passes through the center c2a of the protrusion 42a is defined as "L2a," and a line that intersects perpendicularly with the central axis Ca and passes through the center c3a of the protrusion 43a is defined as "L3a." In this case, the angle A1a between the line L1a and the line L2a is 150°, the angle A1b between the line L2a and the line L3a is 60°, and the angle A1c between the line L3a and the line L1a is 150°.

[0021] That is, as shown in FIG. 6, the outer peripheral surface 55a of the stator core 55 has a plurality of protrusions 41a, 42a, and 43a formed at unequal intervals in the circumferential direction. Here, "the plurality of protrusions 41a, 42a, and 43a are formed at unequal intervals in the circumferential direction" means "the plurality of protrusions 41a, 42a, and 43a are not arranged at equal intervals in the circumferential direction." In other words, the protrusions 41a and 42a are arranged with a first interval S1a between them, the protrusions 42a and 43a are arranged with a first interval S1b between them, and the protrusions 43a and 41a are arranged with a first interval S1c between them. In this case, the length of the first interval S1b is different from the lengths of the first interval S1a and the first interval S1c. That is, the plurality of protrusions 41a, 42a, 43a are arranged at first intervals in the circumferential direction, and at least one of the first intervals is different from the other first intervals.

[0022] Furthermore, the width dimension of the protrusion 41a is "w1a," the width dimension of the protrusion 42a is "w2a," and the width dimension of the protrusion 43a is "w3a." The width dimension w2a and the width dimension w3a are the same, and the width dimension w1a is different from the width dimension w2a and the width dimension w3a. Note that the width dimensions w1a, w2a, and w3a of the protrusions 41a, 42a, and 43a may be the same. Furthermore, the width dimensions of the protrusions 41a, 42a, and 43a refer to the length dimensions of the protrusions 41a, 42a, and 43a in the circumferential direction.

[0023] Next, the multiple recesses 41b, 42b, and 43b formed in the base member 12 will be described. As shown in Fig. 6, a line that is perpendicular to the central axis Ca and passes through the center c1b of the recess 41b is designated "L1b." Furthermore, a line that is perpendicular to the central axis Ca and passes through the center c2b of the recess 42b is designated "L2b," and a line that is perpendicular to the central axis Ca and passes through the center c3b of the recess 43b is designated "L3b." In this case, the angle between the line L1b and the line L2b is 150°, the angle between the line L2b and the line L3b is 60°, and the angle between the line L3b and the line L1b is 150°.

[0024] That is, as shown in FIG. 6, a plurality of recesses 41b, 42b, 43b are formed at unequal intervals in the circumferential direction on the inner circumferential surfaces 31a, 32a of the support walls 31, 32. Here, "a plurality of recesses 41b, 42b, 43b are formed at unequal intervals in the circumferential direction" means "a plurality of recesses 41b, 42b, 43b are not arranged at equal intervals in the circumferential direction." In other words, the recesses 41b and 42b are arranged with a second distance S2a between them, the recesses 42b and 43b are arranged with a second distance S2b between them, and the recesses 43b and 41b are arranged with a second distance S2c between them. In this case, the length of the second distance S2b is different from the lengths of the second distance S2a and the second distance S2c. That is, the recesses 41b, 42b, 43b are arranged at second intervals in the circumferential direction, and at least one of the second intervals is different from the other second intervals.

[0025] Furthermore, the width dimension of recess 41b is "w1b," the width dimension of recess 42b is "w2b," and the width dimension of recess 43b is "w3b." The width dimension w2b and the width dimension w3b are the same, and the width dimension w1b is different from the width dimension w2b and the width dimension w3b. Note that the width dimensions w1b, w2b, and w3b of recesses 41b, 42b, and 43b may be the same. Furthermore, the width dimensions of recesses 41b, 42b, and 43b refer to the length dimensions of recesses 41b, 42b, and 43b in the circumferential direction.

[0026] [Effects of convex and concave parts] As described above, the outer peripheral surface 55a of the stator core 55 constituting the stator 20 has a plurality of protrusions 41a, 42a, and 43a formed at unequal intervals in the circumferential direction, and the inner peripheral surfaces 31a and 32a of the support walls 31 and 32 constituting the base member 12 have a plurality of recesses 41b, 42b, and 43b formed at unequal intervals in the circumferential direction. This makes it possible to uniquely determine the relative position of the base member 12 and the stator 20 when attaching the stator 20 to the base member 12. In other words, when the stator 20 is rotated by a predetermined angle in the circumferential direction from the position shown in FIG. 4A or 5A, it is impossible to engage the protrusions 41a, 42a, and 43a with the recesses 41b, 42b, and 43b, and it is therefore impossible to attach the stator 20 to the base member 12.

[0027] In this way, the relative position between the base member 12 and the stator 20 is uniquely determined, so the stator 20 can be attached to the base member 12 easily and with high precision. That is, because the stator 20 can be attached in an appropriate position, the rotating magnetic field of the stator 20 can be appropriately generated, thereby improving the performance of the electric motor 10. Moreover, because the stator 20 can be positioned relative to the base member 12 without using a complicated jig, the manufacturing cost of the electric motor 10 can be reduced. Furthermore, because the protrusions 41 a, 42 a, and 43 a and the recesses 41 b, 42 b, and 43 b mesh with each other, relative rotation between the base member 12 and the stator 20 can be prevented. Therefore, even if the stator 20 receives a rotational reaction force from the rotor 15 during motor operation, rotation of the stator 20 relative to the base member 12 can be prevented, allowing the electric motor 10 to function properly.

[0028] Furthermore, the clearance between the protrusion 41a and the recess 41b is set narrower than the clearance between the protrusion 42a and the recess 42b and the clearance between the protrusion 43a and the recess 43b. This allows the protrusion 41a to be inserted into the recess 41b, and then the protrusion 42a can be inserted into the recess 42b, and the protrusion 43a can be inserted into the recess 43b. In other words, the stator 20 can be easily attached to the base member 12 while improving the positioning accuracy between the base member 12 and the stator 20. Furthermore, as described above, the protrusions 41a, 42a, and 43a of the stator core 55 are not painted. This allows the clearance between the protrusion 41a and the recess 41b, the clearance between the protrusion 42a and the recess 42b, and the clearance between the protrusion 43a and the recess 43b to be appropriately set without being affected by painting.

[0029] [Thinner electric motors] FIG. 7 is a diagram showing the positional relationship between the base member 12 and the flexible printed circuit board 14. As shown in FIG. 7, the base member 12 has two support walls 31, 32 bent at approximately right angles at the outer edge 30a of the base plate 30. That is, the outer edge 30a of the base plate 30 has first sections Se1a, Se1b where the support walls 31, 32 are provided, and second sections Se2a, Se2b where the support walls 31, 32 are not provided. The second section Se2a of the base plate 30 has a wiring lead-out portion 14a of the flexible printed circuit board 14 disposed therein, and a mounting plate 33 extending from the base plate 30. The second section Se2b of the base plate 30 has a mounting plate 34 extending from the base plate 30. This allows the flexible printed circuit board 14 to be assembled to the electric motor 10 while suppressing an increase in the thickness of the electric motor 10. The mounting plates 33, 34 can be provided to the electric motor 10 while suppressing an increase in the thickness of the electric motor 10.

[0030] [Another embodiment 1] In the example shown in Fig. 6, protrusions 42a, 43a having the same width dimension are formed on stator core 55, and recesses 42b, 43b having the same width dimension are formed on base member 12, but the present invention is not limited to this. Fig. 8 is a diagram showing an example of protrusions formed on stator core 60 and recesses formed on base member 61. In Fig. 8, parts and members similar to those shown in Fig. 6 are designated by the same reference numerals, and description thereof will be omitted.

[0031] As shown in FIG. 8, a plurality of protrusions 41a, 42a, and 44a are formed at unequal intervals in the circumferential direction on the outer peripheral surface 60a of the stator core 60. Here, a line perpendicular to the central axis Ca and passing through the center c4a of each protrusion 44a is designated as "L4a." In this case, the angle A1a between the line L1a and the line L2a is 150°, the angle A1b between the line L2a and the line L4a is 60°, and the angle A1c between the line L4a and the line L1a is 150°. In this manner, in the stator core 60 in which the line L2a and the line L4a are symmetrical with respect to the line L1a, the width w4a of the protrusion 44a is greater than the width w2a of the protrusion 42a.

[0032] Furthermore, a plurality of recesses 41b, 42b, 44b are formed at unequal intervals in the circumferential direction on inner circumferential surfaces 62a, 63a of support walls (support wall portions) 62, 63 of the base member 61. Here, a line perpendicular to the central axis Ca and passing through the center c4b of the recess 44b is designated "L4b." In this case, the angle between line L1b and line L2b is 150°, the angle between line L2b and line L4b is 60°, and the angle between line L4b and line L1b is 150°. In this manner, in the base member 61 in which line L2b and line L4b are symmetrical with respect to line L1b as the axis of symmetry, the width w4b of the recess 44b is greater than the width w2b of the recess 42b.

[0033] In this way, by making the width dimensions of the protrusions 42a and 44a different from each other and by making the width dimensions of the recesses 42b and 44b different from each other, it is possible to uniquely determine the relative position of the base member 61 and the stator core 60, as with the electric motor 10 described above. Furthermore, since it is impossible to assemble the stator core 60 to the base member 61 upside down, it is possible to prevent incorrect assembly of the stator core 60 to the base member 61. In other words, if the stator core 60 is turned upside down, the protrusions 44a of the stator core 60 will face the recesses 42b of the support wall 63, making it impossible to attach the stator core 60 to the base member 61.

[0034] [Another embodiment 2] In the example shown in Fig. 6, three protrusions 41a, 42a, and 43a are formed on stator core 55, and three recesses 41b, 42b, and 43b are formed on base member 12, but the present invention is not limited to this. Fig. 9 is a diagram showing an example of protrusions formed on stator core 70 and recesses formed on base member 71. In Fig. 9, parts and members similar to those shown in Fig. 6 are designated by the same reference numerals, and their description will be omitted.

[0035] As shown in Fig. 9, two protrusions 41a, 45a are formed on the outer peripheral surface 70a of the stator core 70 at unequal intervals in the circumferential direction. The protrusions 41a and 45a are spaced apart by a first interval S10a, and the protrusions 45a and 41a are spaced apart by a first interval S10b. As described above, because the protrusions 41a and 45a are formed at unequal intervals in the circumferential direction, the lengths of the first intervals S10a and S10b are different from each other. When a line that is perpendicular to the central axis Ca and passes through the center c5a of the protrusion 45a is defined as "L5a," the angle A5a formed between the line L1a and the line L5a is 165°.

[0036] Furthermore, two recesses 41b, 45b are formed at unequal intervals in the circumferential direction on the inner peripheral surfaces 72a, 73a of the support walls (support wall portions) 72, 73 of the base member 71. Here, the recesses 41b and 45b are arranged with a second interval S20a between them, and the recesses 45b and 41b are arranged with a second interval S20b between them. As described above, because the recesses 41b and 45b are formed with unequal intervals in the circumferential direction, the lengths of the second intervals S20a and S20b are different from each other. Note that when a line that is perpendicular to the central axis Ca and passes through the center c5b of the recess 45b is defined as "L5b," the angle A5b formed between the line L1b and the line L5b is 165°.

[0037] In this way, even when two protrusions 41a, 45a are formed at unequal intervals on the stator core 70 and two recesses 41b, 45b are formed at unequal intervals on the support walls 72, 73 of the base member 71, it is possible to uniquely determine the relative position between the base member 71 and the stator core 70, as in the above-described electric motor 10. Furthermore, since it is impossible to assemble the stator core 70 to the base member 71 upside down, it is possible to prevent incorrect assembly of the stator core 70 to the base member 71. In other words, if the stator core 70 is turned upside down, the protrusions 45a of the stator core 70 will interfere with the support walls 73, making it impossible to attach the stator core 70 to the base member 71.

[0038] [Another embodiment 3] 4A and 5A, protrusions 41a, 42a, and 43a are formed from one end to the other in the thickness direction (vertical direction) of stator core 55, but the present invention is not limited to this. Here, Fig. 10 is a perspective view showing an example of stator core 80 and base member 81. Note that in Fig. 10, parts and members similar to those shown in Fig. 4A and 5A are designated by the same reference numerals and descriptions thereof will be omitted.

[0039] 10, a plurality of protrusions 91a, 92a, 93a are formed at unequal intervals in the circumferential direction on the outer peripheral surface 80a of the stator core 80. The vertical thickness of the protrusions 91a, 92a, 93a is set smaller than the vertical thickness of the stator core 80. The protrusions 91a, 92a, 93a are formed closer to the upper end face than to the lower end face of the stator core 80. In addition, a plurality of recesses 91b, 92b, 93b facing the protrusions 91a, 92a, 93a are formed at unequal intervals in the circumferential direction on the inner peripheral surfaces 82a, 83a of the support walls (support wall portions) 82, 83 of the base member 81.

[0040] In this way, even when the stator core 80 is provided with a plurality of protrusions 91a, 92a, 93a at unequal intervals and the support walls 82, 83 of the base member 81 are provided with a plurality of recesses 91b, 92b, 93b at unequal intervals, it is possible to uniquely determine the relative position between the base member 81 and the stator core 80, as in the case of the electric motor 10 described above. Furthermore, by forming the protrusions 91a, 92a, 93a with a small thickness in the up-down direction on the stator core 80, it is impossible to assemble the stator core 80 to the base member 81 by turning it upside down, thereby preventing incorrect assembly of the stator core 80 to the base member 81. In other words, if the stator core 80 is turned upside down, the stator core 80 protrudes from the support walls 82, 83 of the base member 81, making it impossible to attach the stator core 80 to the base member 81.

[0041] The present invention is not limited to the above-described embodiment and can be modified in various ways without departing from the spirit and scope of the present invention. In the illustrated example, two or three protrusions are formed on the stator cores 55, 60, 70, and 80, but this is not limited thereto, and a stator core having four or more protrusions may be used. Similarly, in the illustrated example, two or three recesses are formed on the base members 12, 61, 71, and 81, but this is not limited thereto, and a base member having four or more recesses may be used.

[0042] In the above description, recesses 41b, 42b, 43b that penetrate through the support walls 31, 32 of the base member 12 in the thickness direction are formed, but this is not limited to this and recesses that do not penetrate through the support walls 31, 32 in the thickness direction may be formed. Also, in the above description, notches are formed as the recesses 41b, 42b, 43b of the support walls 31, 32, but this is not limited to this and openings may be formed as the recesses of the support walls 31, 32.

[0043] In the above description, a sheet metal part is used as the base member 12, but this is not limiting, and the base plate 30 and the support walls 31, 32 may be prepared separately and these parts may be joined together by welding or the like. Also, for example, the base member 12 may be manufactured by cutting, casting, or resin molding.

[0044] 6, the plurality of protrusions 41a, 42a, and 43a are formed at unequal intervals in the circumferential direction, and the plurality of recesses 41b, 42b, and 43b are formed at unequal intervals in the circumferential direction. However, from the viewpoint of uniquely determining the relative positions of the base member 12 and the stator 20, the formation is not limited to unequal intervals. In other words, from the viewpoint of uniquely determining the relative positions of the base member 12 and the stator 20, the plurality of protrusions 41a, 42a, and 43a may be formed at equal intervals in the circumferential direction, and the plurality of recesses 41b, 42b, and 43b may be formed at equal intervals in the circumferential direction. In this case, for example, the vertical dimension of the protrusion 41a may be made different from the vertical dimension of the other protrusions 42a and 43a, and the vertical dimension of the recess 41b may be made different from the vertical dimension of the other recesses 42b and 43b. This makes it possible to uniquely determine the relative position between the base member 12 and the stator 20, even if multiple protrusions 41a, 42a, 43a are formed at equal intervals in the circumferential direction and multiple recesses 41b, 42b, 43b are formed at equal intervals in the circumferential direction. [Explanation of symbols]

[0045] 10...electric motor, 11...cover member, 12...base member, 13...housing, 14...flexible printed circuit board, 14a...wiring lead-out portion, 15...rotor, 16...rotor shaft, 17...pinion, 20...stator, 21...shaft holder (bearing portion), 22...spring washer, 23, 24...bearing, 25...hall element, 26...insulating sheet, 27...cover body, 28...cover Wall, 30... base plate (disk portion), 30a... outer edge, 31... support wall (support wall portion), 31a... inner circumferential surface, 31b... upper end (edge), 32... support wall (support wall portion), 32a... inner circumferential surface, 32b... upper end (edge), 33... mounting plate (mounting portion), 34... mounting plate (mounting portion), 35... through hole, 36... engagement groove, 37... engagement claw, 41a to 45a... convex portion, 41b to 45b... concave portion, 50... rotor Hub, 51... rotor core, 52... permanent magnet, 55... stator core, 55a... outer peripheral surface, 56... teeth, 57... stator coil, 58... insulator, 59... slot, 60... stator core, 60a... outer peripheral surface, 61... base member, 62, 63... support wall (support wall portion), 62a, 63a... inner peripheral surface, 70... stator core, 70a... outer peripheral surface, 71... base member, 72, 73... support Wall (support wall portion), 72a, 73a...inner peripheral surface, 80...stator core, 80a...outer peripheral surface, 81...base member, 82, 83...support wall (support wall portion), 82a, 83a...inner peripheral surface, 91a to 93a...convex portions, 91b to 93b...concave portions, Ca...central axis, S1a, S1b, S1c...first interval, S2a, S2b, S2c...second interval, Se1a, Se1b...first section, Se2a, Se2b...second section

Claims

1. An electric motor having a rotor, a base member that is a sheet metal part including: a disk portion having a bearing portion that rotatably supports the rotor; and a support wall portion that extends from the disk portion in a direction intersecting the disk portion; a stator including a stator core disposed inside the support wall portion and a stator coil wound around the stator core; and a plurality of protrusions are formed on the outer peripheral surface of the stator core at unequal intervals in the circumferential direction, and a plurality of recesses are formed on the inner peripheral surface of the support wall portion at unequal intervals in the circumferential direction, and the plurality of protrusions and the plurality of recesses are engaged with each other, The recess formed in the support wall portion is a notch that penetrates the support wall portion in a thickness direction and opens to an edge of the support wall portion. Electric motor.

2. The plurality of protrusions are arranged at first intervals in the circumferential direction, and at least one of the first intervals is different from the other first intervals, The plurality of recesses are arranged at second intervals in the circumferential direction, and at least one of the second intervals is different from the other second intervals.

2. The electric motor according to claim 1.

3. a width dimension of at least one of the plurality of protrusions is different from a width dimension of the other protrusions, At least one of the plurality of recesses has a width dimension different from the width dimensions of the other recesses.

3. The electric motor according to claim 1 or 2.

4. The base member includes a mounting plate extending radially outward from the disk portion and having a through hole. The electric motor according to any one of claims 1 to 3.

5. an outer edge of the disk portion includes a first section in which the support wall portion is provided and a second section in which the support wall portion is not provided; The mounting plate of the base member extends radially outward from the second section of the disk portion.

5. The electric motor according to claim 4.

6. an outer edge of the disk portion includes a first section in which the support wall portion is provided and a second section in which the support wall portion is not provided; A flexible printed circuit board is disposed in the second section of the disk portion. An electric motor according to any one of claims 1 to 5.

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