Motor and air blower

Abstract

To provide a motor and an air blower capable of suppressing spread of water on a circuit board.SOLUTION: According to an aspect of the present disclosure, there is provided a motor including: a rotor rotatable about a central axis; a stator opposed to a rotor via a gap; a circuit board that overlaps in an axial direction on one side in an axial direction of the stator and is electrically connected to the stator; a coupling part that is coupled to the circuit board; a resin part that covers at least a part of the circuit board and at least a part of the coupling part; and a first boundary part that connects an outer surface of the resin part and the coupling part. The circuit board 21 includes: a contact part that contacts a resin part 25; and a first annular bonding part 45a that is bonded to the resin part and annularly surrounds the coupling part when viewed in a direction orthogonal to the circuit board. An adhesion between the first annular adhesive part and the resin part is greater than the adhesion between the contact part and the resin part.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] BACKGROUND ART A motor is known in which at least a part of a circuit board and at least a part of a component connected to the circuit board are covered with resin (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2023-18900 Summary of the Invention [Problem to be solved by the invention]

[0004] In the motor described above, there is a risk that water may penetrate from the outside of the motor into the boundary between the resin and the components connected to the circuit board, and that the water may reach the circuit board from the boundary and spread over the circuit board.

[0005] In view of the above circumstances, an object of the present invention is to provide a motor and a fan that can prevent water from spreading onto a circuit board. [Means for solving the problem]

[0006] One embodiment of the motor of the present invention includes a rotor rotatable about a central axis, a stator facing the rotor with a gap therebetween, a circuit board axially overlapping and electrically connected to one axial side of the stator, a connecting portion connected to the circuit board, a resin portion covering at least a portion of the circuit board and at least a portion of the connecting portion, and a first boundary portion connecting an outer surface of the resin portion to the connecting portion. The circuit board has a contact portion in contact with the resin portion and a first annular adhesive portion bonded to the resin portion and annularly surrounding the connecting portion when viewed from a direction perpendicular to the circuit board. The adhesion between the first annular adhesive portion and the resin portion is greater than the adhesion between the contact portion and the resin portion.

[0007] One embodiment of a motor of the present invention includes a rotor rotatable about a central axis, a stator having an insulator and facing the rotor with a gap therebetween, a circuit board having a fitting portion into which the insulator is fitted and axially overlapping the stator, a resin portion covering at least a portion of the circuit board, and a second boundary portion connecting an outer surface of the resin portion and the fitting portion. The circuit board has a second annular contact portion in contact with the resin portion and annularly surrounding the fitting portion when viewed from a direction perpendicular to the board surface of the circuit board, and a second annular adhesive portion bonded to the resin portion and annularly surrounding the fitting portion when viewed from a direction perpendicular to the board surface of the circuit board. The adhesion between the second annular adhesive portion and the resin portion is greater than the adhesion between the second annular contact portion and the resin portion.

[0008] One aspect of the blower of the present invention includes the motor described above and an impeller portion provided on the rotor. [Effects of the Invention]

[0009] According to one and other aspects of the present disclosure, in a motor and a blower, it is possible to suppress the spread of water on the surface of a circuit board. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a cross-sectional view of a blower using a motor according to one embodiment. [Figure 2] FIG. 2 is an enlarged view of part II in FIG. [Figure 3] FIG. 3 is a cross-sectional view taken along the line III-III in FIG. [Figure 4] FIG. 4 is an enlarged view of part IV in FIG. [Figure 5] FIG. 5 is a cross-sectional view taken along the VV direction in FIG. [Figure 6] FIG. 6 is a diagram showing a part of the motor of the first modification. [Figure 7] FIG. 7 is a diagram showing a part of the motor of the second modification. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, motors and blowers according to embodiments of the present invention will be described with reference to the drawings. Note that the scope of the present invention is not limited to the following embodiments, and can be modified as desired within the scope of the technical concept of the present invention. In addition, in the following drawings, the scale and number of components may differ from the actual structure in order to make each component easier to understand. Furthermore, liquids such as water, salt water, and other aqueous solutions may sometimes be simply referred to as water.

[0012] In each drawing, a central axis J of a motor in the following embodiments is shown as appropriate. The central axis J is a virtual axis. In the following description, the direction in which the central axis J extends, i.e., the axial direction of the central axis J, will be simply referred to as the "axial direction," the radial direction centered on the central axis J will be simply referred to as the "radial direction," and the circumferential direction centered on the central axis J will be simply referred to as the "circumferential direction." In each drawing, a Z axis parallel to the axial direction is shown. In the following description, the side of the axial direction toward which the arrow of the Z axis points (+Z side) will be referred to as the "upper side," and the side of the axial direction opposite to the side toward which the arrow of the Z axis points (-Z side) will be referred to as the "lower side." In the following embodiments, the lower side corresponds to "one axial side." Note that the terms "upper side" and "lower side" are simply names used to describe the relative positions of the components, and the actual relative positions may be other than those indicated by these names.

[0013] As shown in Fig. 1, blower 10 of this embodiment includes motor 11, impeller unit 13, and housing 17. Housing 17 is frame-shaped and surrounds central axis J, with openings on both axial sides. Motor 11 and impeller unit 13 are housed radially inside housing 17. Motor 11 includes shaft 27, rotor 15, stator 19, support unit 24, bottom wall unit 26, circuit board 21, and resin unit 25.

[0014] The shaft 27 extends in the axial direction centered on a central axis J. The shaft 27 is supported by the support portion 24 so as to be rotatable about the central axis J. A lower end portion of the shaft 27 is disposed inside a cylindrical portion 24a, which will be described later.

[0015] The rotor 15 is fixed to the upper end of the shaft 27. The rotor 15 is rotatable around the shaft 27. The rotor 15 has an annular wall portion 29 and a rotor magnet 28. The annular wall portion 29 is annular and surrounds the central axis J. The annular wall portion 29 is located radially outside the stator 19 and surrounds the stator 19. The rotor magnet 28 is fixed to the radially inner surface of the annular wall portion 29. The rotor 15 is provided with an impeller portion 13. The impeller portion 13 has a plurality of blade portions 13a provided on the radially outer surface of the annular wall portion 29.

[0016] The stator 19 faces the rotor 15 via a gap. The stator 19 is located radially inside the annular wall portion 29. The stator 19 is supported by the radially outer surface of a cylindrical portion 24a (described later) of the support portion 24. The stator 19 has a stator core 31, coils 33, and insulators 35. The stator core 31 has a core back 31a surrounding the cylindrical portion 24a and teeth 31b extending radially outward from the core back 31a. The radially inner surface of the core back 31a is fixed to the radially outer surface of the cylindrical portion 24a (described later). The coils 33 are attached to the stator core 31 via the insulators 35.

[0017] The insulator 35 includes a tubular portion 35a, a coil arrangement portion 35b, and a holding portion 35c. The insulator 35 is made of, for example, resin. The tubular portion 35a has a cylindrical shape surrounding the central axis J. The tubular portion 35a protrudes downward from the core back 31a of the stator core 31. In this embodiment, the tubular portion 35a has a substantially cylindrical shape centered on the central axis J and open on both sides in the axial direction. The tubular portion 35a is located radially outward of a tubular portion 24a of the support portion 24, which will be described later.

[0018] The cylindrical portion 35a has a small diameter portion 35d. The small diameter portion 35d is the lower end portion of the cylindrical portion 35a. The outer diameter of the small diameter portion 35d is smaller than the outer diameter of a portion of the cylindrical portion 35a located above the small diameter portion 35d. A step portion 35e having a downward-facing step surface is provided between the outer peripheral surface of the small diameter portion 35d and the outer peripheral surface of the portion of the cylindrical portion 35a located above the small diameter portion 35d. The small diameter portion 35d is fitted into a through hole 21j of the circuit board 21, which will be described later. In this embodiment, the inner peripheral surface of the through hole 21j is a fitting portion 49 into which the insulator 35 is fitted. The downward-facing step surface of the step portion 35e comes into contact with the circuit board 21.

[0019] The coil arrangement portion 35b protrudes radially outward from the radially outer surface of the cylindrical portion 35a. The coil arrangement portion 35b is located between the coil 33 and the teeth 31b. The holding portion 35c protrudes downward from the radially outer end of the coil arrangement portion 35b. The holding portion 35c supports an upper portion of the conductive member 37, which will be described later.

[0020] The support portion 24 supports the stator 19. The support portion 24 includes a cylindrical portion 24a and a bearing 24b. The cylindrical portion 24a is cylindrical and surrounds the central axis J. In this embodiment, the cylindrical portion 24a is generally cylindrical and has a center on the central axis J, with both ends open in the axial direction. A stator core 31 is fixed to the radially outer surface of the cylindrical portion 24a. A bearing 24b is held inside the cylindrical portion 24a. The bearing 24b rotatably supports the shaft 27. In this embodiment, the bearing 24b is a ball bearing. The bearing 24b is fitted and held inside the cylindrical portion 24a. Two bearings 24b are provided, spaced apart in the axial direction. Note that the bearing 24b may be a rolling bearing other than a ball bearing, or may be a plain bearing, as long as it can rotatably support the shaft 27. The bottom wall portion 26 is connected to the lower end of the cylindrical portion 24a. In this embodiment, the bottom wall portion 26 has a generally circular plate shape that expands in the radial direction.

[0021] The circuit board 21 is located below the stator 19. The circuit board 21 overlaps the stator 19 in the axial direction. The surface of the circuit board 21 faces the axial direction. The surface of the circuit board 21 is perpendicular to the axial direction. In this specification, the "direction perpendicular to the circuit board 21" means the direction perpendicular to the surface of the circuit board 21. In this embodiment, the "direction perpendicular to the circuit board 21" is the axial direction in which the central axis J extends. The circuit board 21 is located axially between the stator 19 and the bottom wall portion 26.

[0022] The circuit board 21 has a through hole 21j that passes through the circuit board 21 in the axial direction. In this embodiment, the through hole 21j is a circular hole centered on the central axis J. The small diameter portion 35d of the insulator 35 is fitted into the through hole 21j. The circuit board 21 is a printed wiring board on which a wiring pattern is provided.

[0023] As shown in FIG. 2, the circuit board 21 has a substrate main body portion 21a and a resist layer 21c. The substrate main body portion 21a is a plate-shaped member on which a wiring pattern is provided. Resist layers 21c are laminated on the upper surface 21b and the lower surface 21d of the substrate main body portion 21a. The resist layer 21c is an insulating film that protects the wiring patterns (not shown) provided on the upper surface 21b and the lower surface 21d of the substrate main body portion 21a. The provision of the resist layer 21c makes it possible to prevent solder and dirt from adhering to the surface of the substrate main body portion 21a other than the area to be soldered when soldering electronic components to the wiring patterns provided on the substrate main body portion 21a.

[0024] The coil 33 is electrically connected to the circuit board 21 via a conductive member 37. This electrically connects the circuit board 21 to the stator 19. The conductive member 37 is a metal member extending in the axial direction. In this embodiment, the conductive member 37 is a binding pin around which an end of the winding 33a constituting the coil 33 is wound. The conductive member 37 is held by a holding portion 35c of the insulator 35. The conductive member 37 protrudes downward from the holding portion 35c. A lower portion of the conductive member 37 is axially inserted into a through hole 21g provided in the circuit board 21. The through hole 21g is configured by a hole portion 21h that axially penetrates the board main body portion 21a and has a plating film 21i provided on the inner surface thereof. Land portions 41 that are electrically connected to the plating film 21i of the through hole 21g are provided on the upper surface 21b and the lower surface 21d of the board main body portion 21a, respectively. As shown in FIG. 3, the land portion 41 has a circular ring shape that surrounds the through-hole 21g on the upper surface 21b and the lower surface 21d. As shown in FIG. 2, the conductive member 37 is electrically connected to the land portion 41 and the plating film 21i by the solder portion 39. The solder portion 39 is connected to the land portion 41 and the plating film 21i. This connects the solder portion 39 to the circuit board 21. In this embodiment, the portion of the solder portion 39 that comes into contact with the circuit board 21 is the connecting portion 39a connected to the circuit board 21. In other words, in this embodiment, the connecting portion 39a connected to the circuit board 21 includes the portion of the solder portion 39 that connects the circuit board 21 and the conductive member 37 and that is connected to the circuit board 21.

[0025] An inverter circuit that supplies current to the coil 33 of the stator 19 is provided on the circuit board 21. The inverter circuit supplies current to the coil 33 via a conductive member 37. The inverter circuit causes the circuit board 21 to switch the current flowing through the stator 19.

[0026] As shown in FIG. 1, the resin portion 25 covers at least a portion of the circuit board 21 and at least a portion of the stator 19. In this embodiment, the resin portion 25 covers almost the entire circuit board 21. As shown in FIG. 4, the resin portion 25 covers a first surface 21e facing upward among the board surfaces of the circuit board 21 and a second surface 21f facing downward among the board surfaces of the circuit board 21. The first surface 21e is the upper surface of the circuit board 21. The first surface 21e includes the upper surface of the resist layer 21c provided on the upper surface 21b of the board main body 21a, the upper surfaces of the lands 41 provided on the upper surface 21b of the board main body 21a, and portions of the upper surface 21b of the board main body 21a where the resist layer 21c is not laminated. The second surface 21f is the lower surface of the circuit board 21. The second surface 21f includes the lower surface of the resist layer 21c provided on the lower surface 21d of the substrate main body portion 21a, the lower surface of the land portion 41 provided on the lower surface 21d of the substrate main body portion 21a, and a portion of the lower surface 21d of the substrate main body portion 21a on which the resist layer 21c is not laminated.

[0027] In this embodiment, the resin portion 25 covers the entire stator 19 except for the radially inner surface of the cylindrical portion 35a of the insulator 35, the radially inner surface of the core back 31a, and the radially outer surfaces of the teeth 31b. The resin portion 25 covers at least a portion of the solder portion 39, which is a connecting portion. In this embodiment, the resin portion 25 covers the entire solder portion 39. The resin portion 25 is made of a resin such as hot melt, for example. The resin portion 25 is made, for example, by insert molding using the stator 19 and the circuit board 21 as insert members.

[0028] As shown in FIG. 2 , the motor 11 of this embodiment includes a first boundary 43a connecting the outer surface 25a of the resin portion 25 and the connecting portion 39a of the solder portion 39. The outer surface 25a of the resin portion 25 is the surface of the resin portion 25 that is exposed to the outside. The first boundary 43a is a portion that can serve as a path for water to penetrate from the outer surface 25a of the resin portion 25 to the connecting portion between the solder portion 39 and the circuit board 21, i.e., the connecting portion 39a. The first boundary 43a of this embodiment includes a portion 43a1, a portion 43a2, a portion 43a3, and a portion 43a4. The portion 43a1 is a boundary between the radially outer end of the tooth 31b and the resin portion 25. The radially outer end of the portion 43a1 is connected to the radially outer surface of the tooth 31b exposed from the resin portion 25 and the outer surface 25a of the resin portion 25. The portion 43a2 is a boundary between the holding portion 35c of the insulator 35 and the resin portion 25. The portion 43a3 is a boundary between the winding 33a and the conductive member 37 of the coil 33 and the resin portion 25. The portion 43a4 is a boundary between the resin portion 25 and the outer surface of the solder portion 39 connected to the circuit board 21. For example, it is conceivable that water may enter the portion 43a1 from between the radially outer surface of the tooth 31b exposed from the resin portion 25 and the outer surface 25a of the resin portion 25. In this case, the water that has entered the portion 43a1 may flow through the portions 43a2, 43a3, and 43a4 in this order, and reach the portion of the solder portion 39 connected to the circuit board 21, i.e., the connecting portion 39a.

[0029] As shown in FIG. 4 , the motor 11 of this embodiment includes a second boundary portion 43b connecting the outer surface 25a of the resin portion 25 and the mating portion 49. The second boundary portion 43b is a portion that can serve as a path for water to enter from the outer surface 25a of the resin portion 25 to the mating portion 49. In this embodiment, the second boundary portion 43b includes a portion 43b1. The portion 43b1 is a boundary between the resin portion 25 and the lower end surface of the small diameter portion 35d of the insulator 35. A radially inner end of the portion 43b1 is connected to the radially inner surface of the small diameter portion 35d exposed from the resin portion 25 and the outer surface 25a of the resin portion 25. A radially outer end of the portion 43b1 is connected to the inner circumferential surface of the through hole 21j of the circuit board 21. For example, water may enter the portion 43b1 between the radially inner surface of the small diameter portion 35d exposed from the resin portion 25 and the outer surface 25a of the resin portion 25. In this case, the water that has flowed through the portion 43b1 may reach the inner circumferential surface of the through-hole 21j, that is, the fitting portion 49.

[0030] If water reaches the connecting portion 39a through the first boundary portion 43a described above, there is a risk that the water will move from the connecting portion 39a onto the circuit board 21 and spread onto the circuit board 21. Furthermore, if water reaches the fitting portion 49 through the second boundary portion 43b, there is a risk that the water will spread from the fitting portion 49 onto the circuit board 21. In this embodiment, the motor 11 is provided with a structure for preventing water that has entered the first boundary portion 43a and the second boundary portion 43b from spreading onto the circuit board 21. This structure will be described below.

[0031] First, the structure for preventing water from entering the first boundary portion 43a will be described. As shown in FIG. 2, the circuit board 21 has a contact portion 45 that contacts the resin portion 25 and a first annular adhesive portion 47 that adheres to the resin portion 25. The contact portion 45 is a portion of the first surface 21e and the second surface 21f of the circuit board 21 that is formed by the surface of the resist layer 21c. The contact portion 45 has a first annular contact portion 45a. As shown in FIG. 3, the first annular contact portion 45a has an annular shape that surrounds the solder portion 39 when viewed from an axial direction perpendicular to the circuit board 21. In this embodiment, the first annular contact portion 45a has an annular shape. The first annular contact portion 45a is disposed adjacent to the outer side of the land portion 41. The first annular contact portion 45a surrounds the land portion 41 when viewed from the axial direction. In this embodiment, the first annular contact portion 45a has an annular shape that is disposed coaxially with the land portion 41.

[0032] The first annular adhesive portion 47 is a part of the first surface 21e of the circuit board 21. When viewed from an axial direction perpendicular to the circuit board 21, the first annular adhesive portion 47 surrounds the connecting portion 39a of the solder portion 39 in an annular shape. In this embodiment, the first annular adhesive portion 47 is annular. The first annular adhesive portion 47 is located outside the land portion 41 and the first annular contact portion 45a. The first annular adhesive portion 47 is disposed adjacent to the outside of the first annular contact portion 45a. When viewed from the axial direction, the first annular adhesive portion 47 surrounds the land portion 41 and the first annular contact portion 45a. In this embodiment, the first annular adhesive portion 47 is annular and disposed coaxially with the land portion 41 and the first annular contact portion 45a. As shown in FIG. 2, in this embodiment, the first annular adhesive portion 47 is formed by the surface of the board main body portion 21a. The first annular adhesive portion 47 is formed by providing a portion on the upper surface 21b of the substrate main body portion 21a where the resist layer 21c is not laminated.

[0033] Here, the resist layer 21c constituting the contact portion 45 is a layer that prevents solder, dirt, and the like from adhering to the surface of the board main body portion 21a, and therefore does not easily achieve a sufficient adhesion to the resin portion 25. Therefore, a gap large enough to allow water to diffuse by capillary action may be formed between the contact portion 45 and the resin portion 25. Therefore, in the past, when water reached the connecting portion 39a through the first boundary portion 43a, there was a risk that the water that had migrated from the connecting portion 39a onto the circuit board 21 would pass between the contact portion 45 and the resin portion 25 and spread onto the circuit board 21.

[0034] In contrast, according to this embodiment, the adhesion between the first annular adhesive portion 47, which annularly surrounds the connecting portion 39a as viewed in the axial direction, and the resin portion 25 is greater than the adhesion between the contact portion 45 and the resin portion 25. This prevents water from passing between the first annular adhesive portion 47 and the resin portion 25. This prevents water that has migrated from the connecting portion 39a onto the circuit board 21 from spreading outward beyond the first annular adhesive portion 47. This prevents water from spreading onto the circuit board 21. The adhesion between the circuit board 21 and the resin portion 25 can be measured as a breaking stress using, for example, the tensile shear bond strength test method for adhesives to rigid adherends described in JIS K6850:1999.

[0035] In this embodiment, the contact portion 45 is formed by the surface of the resist layer 21c, and the first annular adhesive portion 47 is formed by the surface of the substrate main body portion 21a. The surface of the substrate main body portion 21a on which the resist layer 21c is not provided is likely to have a stronger adhesive force with the resin portion 25 than the surface of the resist layer 21c. This makes it easier to make the adhesive force between the first annular adhesive portion 47 and the resin portion 25 stronger than the adhesive force between the contact portion 45 and the resin portion 25. Therefore, the first annular adhesive portion 47 can be easily made without using other materials by not laminating the resist layer 21c on part of the surface of the substrate main body portion 21a, or by removing part of the resist layer 21c that is laminated on the surface of the substrate main body portion 21a.

[0036] In the present embodiment, the connecting portion 39a that is connected to the circuit board 21 is the portion of the solder portion 39 that is connected to the circuit board 21. Therefore, the first annular adhesive portion 47 can prevent water that has entered between the surface of the solder portion 39 and the resin portion 25 from spreading onto the circuit board 21.

[0037] As shown in FIG. 3 , in this embodiment, the width of the first annular adhesive portion 47 is greater than the width of the land portion 41 when viewed from the axial direction perpendicular to the circuit board 21. This allows the width of the first annular adhesive portion 47 to be increased, making it more difficult for water to pass between the first annular adhesive portion 47 and the resin portion 25. This further prevents water from spreading outside the first annular adhesive portion 47. The width of the first annular adhesive portion 47 is the dimension between the inner edge and outer edge of the first annular adhesive portion 47 when viewed from the axial direction. The width of the land portion 41 is the dimension between the inner edge and outer edge of the land portion 41 when viewed from the axial direction.

[0038] In this embodiment, the contact portion 45 has a first annular contact portion 45a that surrounds the solder portion 39 when viewed from the axial direction. The first annular contact portion 45a is formed by a surface of a resist layer 21c provided on the circuit board 21, and the first annular adhesive portion 47 surrounds the first annular contact portion 45a when viewed from a direction perpendicular to the circuit board 21. This allows the resist layer 21c to be provided around the portion of the circuit board 21 where the solder portion 39 is to be provided, such as around the land portion 41. Therefore, during soldering, the resist layer 21c that constitutes the first annular contact portion 45a can prevent solder from adhering to the board main body portion 21a. Furthermore, because the first annular contact portion 45a is surrounded by the first annular adhesive portion 47 when viewed from the axial direction, even if water penetrates between the first annular contact portion 45a and the resin portion 25, the water can be prevented from spreading outside the first annular adhesive portion 47.

[0039] Next, the structure for preventing water from entering the second boundary portion 43b will be described. As shown in FIG. 4, the circuit board 21 has a second annular contact portion 51 and a second annular adhesive portion 53. The second annular contact portion 51 is a portion that contacts the resin portion 25. The second annular contact portion 51 is a part of the contact portion 45. That is, in this embodiment, the second annular contact portion 51 is formed by the surface of the resist layer 21c. The second annular contact portion 51 surrounds the fitting portion 49 in an annular shape when viewed from the axial direction. As shown in FIG. 5, in this embodiment, the second annular contact portion 51 has an annular shape centered on the central axis J. As shown in FIG. 4, two second annular contact portions 51 are provided: one on the first surface 21e of the circuit board 21 and the other on the second surface 21f of the circuit board 21. The two second annular contact portions 51 are arranged so as to overlap each other when viewed from the axial direction. The two second annular contact portions 51 may be arranged offset from each other when viewed in the axial direction.

[0040] The second annular adhesive portion 53 is a portion that is adhered to the resin portion 25. In this embodiment, the second annular adhesive portion 53 is formed by a surface of the board main body portion 21a, similar to the first annular adhesive portion 47. As shown in FIG. 5, the second annular adhesive portion 53 annularly surrounds the second annular contact portion 51 and the fitting portion 49 when viewed in the axial direction. As shown in FIG. 4, in this embodiment, two second annular adhesive portions 53 are provided: one on the first surface 21e of the circuit board 21 and the other on the second surface 21f of the circuit board 21. The two second annular adhesive portions 53 are arranged in positions that overlap each other when viewed in the axial direction. The two second annular adhesive portions 53 are arranged adjacent to each other on the radially outer side of the second annular contact portion 51 on each of the first surface 21e and the second surface 21f. Note that the two second annular adhesive portions 53 may be arranged offset from each other when viewed in the axial direction.

[0041] The adhesion between the second annular adhesive portion 53 and the resin portion 25 is greater than the adhesion between the second annular contact portion 51 and the resin portion 25. Therefore, similar to the first annular adhesive portion 47 described above, water is prevented from passing between the second annular adhesive portion 53 and the resin portion 25. This prevents water from spreading beyond the second annular adhesive portion 53 on the circuit board 21, even if water reaches the fitting portion 49 from the second boundary portion 43b. Furthermore, because the fitting portion 49, to which the second boundary portion 43b is connected, is the inner circumferential surface of the through-hole 21j of the circuit board 21, water that reaches the fitting portion 49 may flow onto both the first surface 21e and the second surface 21f of the circuit board 21. In contrast, in this embodiment, the second annular adhesive portion 53 is provided on each of the first surface 21e and the second surface 21f. This prevents water from spreading onto both the first surface 21e and the second surface 21f.

[0042] Furthermore, in this embodiment, the second annular contact portion 51 is provided inside the second annular adhesive portion 53. Therefore, the second annular contact portion 51 can be provided on the periphery of the through hole 21j of the circuit board 21. Because the second annular contact portion 51 is formed by the surface of the resist layer 21c, the resist layer 21c is positioned around the through hole 21j in the circuit board 21. Therefore, when the through hole 21j is formed in the circuit board 21 by press working or the like, the resist layer 21c can prevent burrs and the like from being generated on the inner edge of the through hole 21j.

[0043] 4, the radial width of the second annular contact portion 51 is greater than the radial width of the step portion 35e. The entire step portion 35e can be brought into contact with the second annular contact portion 51 formed by the resist layer 21c. This allows for more stable support of the circuit board 21. The radial width of the step portion 35e is the radial dimension between the inner and outer edges of the step surface facing downward of the step portion 35e.

[0044] Modifications of the above-described embodiment will be described below. In the following description, the same components as those described above will be denoted by the same reference numerals and the description thereof may be omitted.

[0045] (Variation 1) As shown in FIG. 6 , in the motor 111 of this modified example, the circuit board 121 has a plurality of first annular contact portions 45a and a plurality of first annular adhesive portions 47. In this modified example, two first annular contact portions 45a and two first annular adhesive portions 47 are provided. In this embodiment, the first annular contact portions 45a and the first annular adhesive portions 47 are provided in multiple layers, surrounding the connecting portion 39a, when viewed in the axial direction perpendicular to the circuit board 121. Therefore, even if water passes between one first annular adhesive portion 47 and the resin portion 25, the first annular adhesive portions 47 provided outside the one first annular adhesive portion 47 can prevent the water from spreading. Therefore, water that has entered through the first boundary portion 43a can be further prevented from spreading onto the circuit board 121. In this modified example, the first annular contact portions 45a and the first annular adhesive portions 47 are provided in multiple layers, surrounding the connecting portion 39a, when viewed in the axial direction.

[0046] Although not shown, the second annular contact portion 51 and the second annular adhesive portion 53 may be provided in multiple layers surrounding the fitting portion 49 when viewed in the axial direction. This further prevents water that has entered through the second boundary portion 43b from spreading onto the circuit board 121.

[0047] (Variation 2) As shown in FIG. 7 , the circuit board 221 of the motor 211 of this modified example has a primer layer 260 laminated on the surface of the board main body portion 21a. The primer layer 260 is provided, for example, on the entire upper and lower surfaces of the board main body portion 21a. The primer layer 260 may also be provided on only a portion of the upper and lower surfaces of the board main body portion 21a. In this modified example, the first annular adhesive portion 247 is formed by the surface of the primer layer 260. This facilitates increasing the adhesion between the first annular adhesive portion 247 and the resin portion 25. This effectively prevents water from passing between the first annular adhesive portion 247 and the resin portion 25, thereby effectively preventing water from spreading over the circuit board 221. The other configuration of the first annular adhesive portion 247 is similar to the other configuration of the first annular adhesive portion 47 described above. Although not shown, the second annular adhesive portion 53 may also be formed by the surface of the primer layer 260. In this case, as in the case of the first annular adhesive portion 247, the spreading of water onto the circuit board 221 can be further suppressed.

[0048] Although the embodiments and their modifications of the present disclosure have been described above, the configurations and combinations thereof in the embodiments and their modifications are merely examples, and additions, omissions, substitutions, and other modifications of the configurations are possible within the scope of the spirit of the present disclosure. Furthermore, the present disclosure is not limited to the embodiments.

[0049] For example, while the above embodiments have been described using an example of a motor used in a blower, the motor's application is not limited in any way. This embodiment can be applied to motors used for other applications in the same way as the motors with the above-described configurations. Furthermore, while the above description has been given assuming that the same motor includes a first annular contact portion, a first annular adhesive portion, a second annular contact portion, and a second annular adhesive portion, the motor may include only one of the combinations of the first annular contact portion and the first annular adhesive portion, or the combination of the second annular contact portion and the second annular adhesive portion. The above description has been given of an example in which a portion of the stator is exposed from the resin portion. However, this embodiment can also be applied even if the entire stator is embedded in the resin portion. Furthermore, even if water penetrates the resin portion through a damaged portion and reaches the connecting portion or the fitting portion, the first annular adhesive portion or the second annular adhesive portion can prevent the water from spreading.

[0050] The first and second annular adhesive portions provided on the circuit board may be configured in any manner as long as they have a stronger adhesive force than the contact portion provided on the circuit board. The first and second annular adhesive portions may be formed by partially laminating a primer layer on the surface of the resist layer to improve adhesiveness. The connecting portion connected to the circuit board is not limited to the above-described form and may be any portion.

[0051] The present technology can be configured as follows. (1) A motor comprising: a rotor rotatable about a central axis; a stator facing the rotor with a gap therebetween; a circuit board axially overlapping and electrically connected to one axial side of the stator; a connecting portion connected to the circuit board; a resin portion covering at least a portion of the circuit board and at least a portion of the connecting portion; and a first boundary portion connecting an outer surface of the resin portion to the connecting portion, wherein the circuit board has a contact portion in contact with the resin portion and a first annular adhesive portion bonded to the resin portion and surrounding the connecting portion in an annular shape when viewed from a direction perpendicular to the circuit board, and wherein the adhesion force between the first annular adhesive portion and the resin portion is greater than the adhesion force between the contact portion and the resin portion. (2) The motor described in (1), wherein the circuit board has a substrate main body portion and a resist layer laminated on the surface of the substrate main body portion, the contact portion is formed by the surface of the resist layer, and the first annular adhesive portion is formed by the surface of the substrate main body portion. (3) The motor described in (1), wherein the circuit board has a substrate main body portion and a primer layer laminated on the surface of the substrate main body portion, and the first annular adhesive portion is formed by the surface of the primer layer. (4) A motor described in any one of (1) to (3), wherein the stator has a coil, the coil is electrically connected to the circuit board via a conductive member, and the connecting portion includes a portion of a solder portion connecting the circuit board and the conductive member that is connected to the circuit board. (5) The motor described in (4), wherein the solder portion is connected to a land portion of the circuit board, and the width of the first annular adhesive portion is greater than the width of the land portion when viewed in a direction perpendicular to the circuit board. (6) A motor described in (4) or (5), wherein the contact portion has a first annular contact portion that surrounds the solder portion when viewed from a direction perpendicular to the circuit board, the first annular contact portion is formed by the surface of a resist layer provided on the circuit board, and the first annular adhesive portion surrounds the first annular contact portion when viewed from a direction perpendicular to the circuit board. (7) The motor according to (6), wherein the first annular contact portion and the first annular adhesive portion are provided in multiple layers surrounding the connecting portion when viewed from a direction perpendicular to the circuit board. (8) A motor comprising: a rotor rotatable about a central axis; a stator having an insulator and facing the rotor with a gap therebetween; a circuit board having a fitting portion into which the insulator is fitted and overlapping the stator in the axial direction; a resin portion covering at least a portion of the circuit board; and a second boundary portion connecting an outer surface of the resin portion and the fitting portion, wherein the circuit board has a second annular contact portion in contact with the resin portion and annularly surrounding the fitting portion when viewed from a direction perpendicular to the plate surface of the circuit board; and a second annular adhesive portion bonded to the resin portion and annularly surrounding the fitting portion when viewed from a direction perpendicular to the plate surface of the circuit board, wherein the adhesion between the second annular adhesive portion and the resin portion is greater than the adhesion between the second annular contact portion and the resin portion. (9) A blower comprising the motor according to any one of (1) to (8) and an impeller portion provided on the rotor.

[0052] The configurations and methods described in this specification can be combined as appropriate within the scope of not being mutually contradictory. [Explanation of symbols]

[0053] 10...blower, 11,111,211...motor, 13...impeller portion, 15...rotor, 19...stator, 21,121,221...circuit board, 21a...board main body portion, 21c...resist layer, 25...resin portion, 25a...outer surface, 33...coil, 35...insulator, 37...conductive member, 39...solder portion, 39a...connecting portion, 41...land portion, 43a...first boundary portion, 43b...second boundary portion, 45...contact portion, 45a...first annular contact portion, 47,247...first annular adhesive portion, 49...fitting portion, 51...second annular contact portion, 53...second annular adhesive portion, 260...primer layer, J...central axis

Claims

1. a rotor rotatable about a central axis; a stator facing the rotor with a gap therebetween; a circuit board that overlaps the stator in the axial direction and is electrically connected to the stator on one axial side of the stator; a connecting portion connected to the circuit board; a resin portion covering at least a portion of the circuit board and at least a portion of the connecting portion; a first boundary portion connecting an outer surface of the resin portion and the connecting portion; Equipped with The circuit board includes: a contact portion that contacts the resin portion; a first annular adhesive portion that is bonded to the resin portion and that annularly surrounds the connecting portion when viewed in a direction perpendicular to the circuit board; and The adhesion force between the first annular adhesive portion and the resin portion is greater than the adhesion force between the contact portion and the resin portion.

2. The circuit board includes: a substrate main body; a resist layer laminated on the surface of the substrate body; and the contact portion is formed by a surface of the resist layer, The motor according to claim 1 , wherein the first annular adhesive portion is formed by a surface of the substrate body portion.

3. The circuit board includes: a substrate main body; a primer layer laminated on the surface of the substrate body, The motor according to claim 1 , wherein the first annular adhesive portion is formed by a surface of the primer layer.

4. the stator has a coil; the coil is electrically connected to the circuit board via a conductive member; The motor according to claim 1 , wherein the connecting portion includes a portion of a solder portion that connects the circuit board and the conductive member, the portion being connected to the circuit board.

5. the solder portion is connected to a land portion of the circuit board, The motor according to claim 4 , wherein the width of the first annular adhesive portion is greater than the width of the land portion when viewed in a direction perpendicular to the circuit board.

6. the contact portion has a first annular contact portion that surrounds the solder portion when viewed in a direction perpendicular to the circuit board, the first annular contact portion is formed by a surface of a resist layer provided on the circuit board; The motor according to claim 4 , wherein the first annular adhesive portion surrounds the first annular contact portion when viewed in a direction perpendicular to the circuit board.

7. The motor according to claim 6 , wherein the first annular contact portion and the first annular adhesive portion are provided in multiple layers surrounding the connecting portion when viewed from a direction perpendicular to the circuit board.

8. a rotor rotatable about a central axis; a stator having an insulator and facing the rotor with a gap therebetween; a circuit board having a fitting portion into which the insulator is fitted and overlapping the stator in the axial direction; a resin portion covering at least a portion of the circuit board; a second boundary portion connecting an outer surface of the resin portion and the fitting portion; Equipped with The circuit board includes: a second annular contact portion that contacts the resin portion and surrounds the fitting portion in an annular shape when viewed from a direction perpendicular to the surface of the circuit board; a second annular adhesive portion that is bonded to the resin portion and that annularly surrounds the fitting portion when viewed from a direction perpendicular to the surface of the circuit board; and The adhesion force between the second annular adhesive portion and the resin portion is greater than the adhesion force between the second annular contact portion and the resin portion.

9. A motor according to any one of claims 1 to 8; an impeller portion provided on the rotor; A blower comprising:

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