JP7131032B2 - motor and blower - Google Patents

Description

The present invention relates to a motor and an air blower having the same.

A conventional brushless motor is disclosed in Patent Document 1. The brushless motor disclosed in Patent Document 1 is constructed by assembling a rotor assembly to a stator assembly through a rotor shaft. The stator assembly has a bearing housing fixed on an iron substrate, and a pair of oil-impregnated slide bearings disposed at the upper end and intermediate portion of the bearing housing support the rotor shaft. A thrust bearing disposed at the bottom of the bearing housing supports the lower end of the rotor shaft. An annular thrust-attracting magnet disposed on the thrust bearing, and a retainer washer made of a magnetic material that is fitted near one end of the rotor shaft and is magnetically attracted to the thrust-attracting magnet are provided.

JP-A-2000-50595

However, the brushless motor described in Patent Literature 1 has a configuration including an annular thrust-attracting magnet and a retaining washer that is magnetically attracted to the thrust-attracting magnet. This complicates assembly of the rotor shaft.

An object of the present invention is to provide a motor that is easy to assemble and has high rotational accuracy.

To provide a motor which is easy to assemble and has high rotational accuracy.
A motor having a rotor that rotates around a central axis J that extends vertically. A base portion 11 that is positioned below the rotor and holds a bearing 13, and the attraction magnet 162 that is held by the base portion is housed. and a chip holder 161 . The tip holder includes a plate-like bottom portion 165, a tubular portion 166 extending from the bottom portion, and a flange portion 167 extending radially outward from the tubular portion. At least a portion of the flange portion is fixed inside the base portion. At least a portion of the upper surface 1650 of the bottom is perpendicular to the central axis, the axial length of the attraction magnet is shorter than the axial length of the cylindrical portion, the lower surface of the attraction magnet is in contact with at least a portion 1652 of the upper surface of the bottom, At least part of the radially outer surface of the attraction magnet is in contact with the radially inner surface of the cylindrical portion, the housing is made of resin, at least part of the flange portion is covered with resin, and the radial direction of the flange portion is The outer end is located outside the radially outer end of the bearing.

According to the motor according to the exemplary embodiment of the present invention, it is possible to easily assemble and improve the rotational accuracy.

FIG. 1 is a perspective view of a blower device according to the present invention. FIG. 2 is an exploded perspective view of the blower device according to the present invention. FIG. 3 is a vertical cross-sectional view of the air blower cut along a plane including the central axis. FIG. 4 is an enlarged cross-sectional view of a portion of the housing where the tip holder and the attraction magnet are arranged. FIG. 5 is a cross-sectional perspective view of a longitudinal section of the tip holder, the attraction magnet and the thrust plate. FIG. 6 is an exploded perspective view of the tip holder, attraction magnet and thrust plate. FIG. 7 is an enlarged cross-sectional view of another example of the magnetic attraction portion. FIG. 8 is a perspective view of still another example of the magnetic attraction part. FIG. 9 is a perspective view of still another example of the magnetic attraction part. FIG. 10 is a plan view of the base to which the circuit board is attached. FIG. 11 is an enlarged perspective view of the base portion with the circuit board removed. FIG. 12 is a cross-sectional perspective view enlarging the vicinity of the substrate holding portion. FIG. 13 is a perspective view of the stator as seen from below. 14 is a bottom view of the stator shown in FIG. 13. FIG. FIG. 15 is a perspective view of the enlarged guide portion viewed from above. FIG. 16 is a perspective view of an enlarged guide portion viewed from below. FIG. 17 is an enlarged cross-sectional view of the stator and the base including the guides. FIG. 18 is an enlarged cross-sectional view of the stator and the base including another example of the guide.

Exemplary embodiments of the invention are described in detail below with reference to the drawings. In this specification, in the blower A, the direction parallel to the central axis J of the blower A is the “axial direction”, the direction perpendicular to the central axis J of the blower A is the “radial direction”, and the A direction along an arc centered on the central axis J is called a “circumferential direction”. Similarly, with respect to the impeller 20, the directions coinciding with the axial direction, the radial direction, and the circumferential direction of the blower device A in a state of being incorporated into the blower device A are simply referred to as the “axial direction,” the “radial direction,” and the “circumferential direction,” respectively. called "direction". Further, in this specification, the axial direction of the blower A is defined as the vertical direction. The vertical direction is simply a name used for explanation, and does not limit the positional relationship and direction in the operating state of the blower A.

(First embodiment)
<1. Overall Configuration of Air Blower>
A blower device of an exemplary embodiment of the invention will now be described. FIG. 1 is a perspective view of a blower device according to the present invention. FIG. 2 is an exploded perspective view of the blower device according to the present invention. FIG. 3 is a vertical cross-sectional view of the air blower cut along a plane including the central axis. A blower device A includes a motor 10 and an impeller 20 .

The impeller 20 rotates around a central axis J extending vertically. The motor 10 is arranged below the impeller 20 and rotates the impeller 20 .

<2. Configuration of impeller>
The impeller 20 is a so-called centrifugal fan impeller that generates an airflow radially outward by rotation. When the impeller 20 rotates, air is taken in from the radially central portion of the upper surface, and the taken-in air is sent out radially outward. The impeller 20 is, for example, a resin molding. Engineering plastics can be mentioned as the resin that constitutes the impeller 20 . Engineering plastics are resins with excellent mechanical properties such as strength and heat resistance. Note that the impeller 20 may be made of a material such as metal.

As shown in FIGS. 1, 2, and 3, the impeller 20 has an impeller base 21, an impeller hub 22, a plurality of blades 23, and a support frame 24. As shown in FIGS. The impeller base 21 is disc-shaped. The impeller hub 22 extends upward from the radially central portion of the impeller base 21 . The impeller base 21 has an annular shape, and its radial inner edge is connected to the radial outer edge of the impeller hub 22 . That is, the impeller base 21 is connected to the radial outer edge of a hub inclined portion 222 of the impeller hub 22, which will be described later.

A plurality of blades 23 (here, as shown in FIG. 1, 11 blades) are arranged at equal intervals in the circumferential direction outside the impeller hub 22 on the upper surface of the impeller base 21 in the radial direction. The radially inner side of the blades 23 is positioned forward in the rotational direction of the impeller 20 (indicated by arrow C in FIG. 1) compared to the radially outer side of the blades 23 . As a result, the impeller 20 rotates in the rotation direction C, thereby generating an airflow directed radially outward. The support frame 24 has an annular shape and is connected to the radial outer edges of the upper ends of the plurality of blades 23 . The support frame 24 is fixed with the plurality of blades 23 . The support frame 24 is a reinforcing member that connects the plurality of blades 23 and reinforces the blades 23 .

The impeller hub 22 includes a hub top plate portion 221 , a hub inclined portion 222 , a hub cylindrical portion 223 and a boss portion 224 . The hub top plate portion 221 has a disk shape that expands in the radial direction. A radial outer edge of the hub top plate portion 221 is connected to the hub inclined portion 222 . The hub inclined portion 222 has an annular cross section taken along a plane orthogonal to the central axis J, and has an inclination directed radially outward toward the axially downward direction. That is, the impeller hub 22 has a shape obtained by truncating a cone, that is, a so-called truncated cone shape.

As shown in FIG. 3, the lower surface of the impeller hub 22 is formed with an upwardly recessed lower surface recess 220 . The hub tubular portion 223 and the boss portion 224 are arranged inside the bottom recessed portion 220 . The boss portion 224 is a convex portion that is provided at the center portion in the radial direction of the lower surface of the hub top plate portion 221 and protrudes downward.

A hole 225 is provided at the center (on the central axis J) of the lower surface of the boss 224 . The hole 225 has a cylindrical shape extending along the central axis J and overlaps the central axis J at its center. An upper end portion of a shaft 12 of the motor 10 , which will be described later, is fixed to the hole portion 225 . That is, impeller 20 is fixed to shaft 12 . By fixing the shaft 12 to the hole 225, the impeller 20 and the shaft 12 are fixed. The impeller 20 rotates around the central axis J with the shaft 12 as the rotation axis. Although the shaft 12 and the impeller 20 are fixed by insert molding in this embodiment, the method is not limited to this. For example, it may be fixed by a method such as press fitting, adhesion, or welding. Alternatively, the upper end of the shaft 12 may be screwed with a screw axially penetrating from the upper surface of the impeller hub 22 . As a method of fixing the impeller 20 and the shaft 12, a method of firmly fixing the impeller 20 and the shaft 12 can be widely adopted.

Hub tubular portion 223 has a cylindrical shape extending downward from the lower surface of hub top plate portion 221 . The center of the tubular hub portion 223 overlaps with the central axis J. As shown in FIG. A later-described magnet holder 152 is fixed to the inner surface of the hub tubular portion 223 . The magnet holder 152 holds the rotor magnet 151 . Note that the center of the rotor magnet 151 overlaps the central axis J by fixing the magnet holder 152 to the hub tube portion 223 . In this embodiment, the magnet holder 152 and the tubular hub portion 223 are fixed by insert molding. The fixing between the magnet holder 152 and the hub tubular portion 223 is not limited to insert molding, and a wide variety of fixing methods that can firmly fix the magnet holder 152 and the hub tubular portion 223 can be employed.

<3. Configuration of Motor 10>
As shown in FIGS. 2 and 3, the motor 10 is arranged inside the impeller 20 in the axial direction. The motor 10 includes a base portion 11 , a shaft 12 , bearings 13 , a stator 14 and a rotor 15 . The motor 10 is a so-called outer rotor type brushless motor, and a rotor 15 radially facing the radially outer surface of a stator 14 rotates around a central axis. That is, the motor 10 has a rotor 15 that rotates around a central axis J that extends vertically. The motor 10 also includes a circuit board 30 .

<3.1 Configuration of base portion 11>
As shown in FIGS. 2 and 3 , the base portion 11 is a plate-like member arranged below the rotor 15 . The base portion 11 includes a plate portion 111 , a housing 112 and three arm portions 113 . The plate portion 111 is positioned at the center in the radial direction when the base portion 11 is viewed from above. The housing 112 has a tubular shape extending upward along the central axis J from the radial center portion of the upper surface of the plate portion 111 . A stator 14 is fixed to the radially outer surface of the housing 112 .

The three arm portions 113 extend radially outward from the radial outer edge of the plate portion 111 . The three arm portions 113 are arranged at regular intervals in the circumferential direction. A vibration isolation member 114 that suppresses the transmission of vibration to the blower A is attached to the radial tip of the arm portion 113 . The air blower A is attached to the equipment to be attached with the vibration isolating member 114 in contact with it. Note that the vibration isolating member 114 may be attached as necessary. The base portion 11 is a resin molding, and the plate portion 111, the housing 112 and the arm portion 113 are molded from the same member. One arm portion 113 of the plurality of arm portions 113 has a lead wire drawing portion 1131 that holds a lead wire, which will be described later.

The base portion 11 has a holding recess 115 recessed along the central axis J from the upper surface of the housing 112 . The bearing 13 and the shaft 12 are attached to the holding recess 115 . The holding recess 115 includes a bearing holding portion 1151 in which the bearing 13 is held, and a small diameter portion 1152 connected to the lower end portion of the bearing holding portion 1151 and having an inner diameter smaller than that of the bearing holding portion 1151 . The lower end portion of the bearing 13 and the bottom surface of the bearing holding portion 1151 axially sandwich and hold a retainer ring 19 to be described later.

<3.2 Structure of Shaft 12 and Bearing 13>
The shaft 12 is cylindrical and extends along the central axis J and is made of a magnetic material. That is, the shaft 12 is made of a magnetic material and extends along the central axis J. As shown in FIG. The shaft 12 is made of iron, for example. The shaft 12 has a retaining groove 121 and a lower convex portion 122 . The retainer groove 121 is a groove that is recessed in the radial direction and extends in the circumferential direction. A retaining ring 19 , which will be described later, is fitted in the retaining groove 121 . The retainer ring 19 is sandwiched and fixed between the lower surface of the bearing 13 and the bottom surface of the bearing holding portion 1151 . The lower convex portion 122 is formed on the lower surface of the shaft 12 . The lower convex portion 122 is a curved surface that slopes toward the center as it goes downward in the axial direction. It should be noted that the center in the radial direction of the lower surface convex portion 122 contacts a thrust plate 163, which will be described later.

Then, the shaft 12 rotates while the lower convex portion 122 is in contact with the thrust plate 163 . In order to reduce the resistance during rotation, it is preferable that the area of the contact surface between the lower convex portion 122 and the thrust plate 163 is small. On the other hand, for example, when contact is made at one point, at least one of the lower convex portion 122 and the thrust plate 163 may be deformed. Therefore, it is preferable that the lower surface convex portion 122 has a shape that can reduce the contact area with the thrust plate 163 and suppress the stress concentration at the contact portion. Examples of such a shape include a spherical surface, a paraboloid of revolution, and the like, which are smooth, in other words, differentiable curved surfaces. In addition to these, a wide range of shapes that can suppress stress concentration at the contact portion while reducing contact resistance can be employed.

The bearing 13 is cylindrical and is press-fitted inside the holding recess 115 . The bearing 13 is thereby fixed in the holding recess 115 , ie the bearing 13 is fixed in the housing 112 . That is, housing 112 holds bearing 13 . Bearing 13 supports shaft 12 . The bearing 13 is a fluid bearing, and a film of lubricating oil (not shown) is interposed between the inner surface of the bearing 13 and the outer surface of the shaft 12 . The oil film reduces the frictional resistance between the inner surface of the bearing 13 and the outer surface of the shaft 12 . That is, the shaft 12 is rotatably supported by the bearings 13 . In other words, the shaft 12 is rotatably supported by the base portion 11 to which the bearing 13 is fixed. That is, the bearing portion 13 rotatably supports the shaft 12 . At least the inner surface of the bearing 13 has a structure that circulates (supplies) oil to the gap between the outer surface of the shaft 12 and the shaft 12 . As such a structure, for example, a porous body can be mentioned.

Shaft 12 is rotatably supported by bearing 13 . The impeller 20 is fixed above the bearing 13 of the shaft 12 , more specifically above the housing 112 . A portion of the lower end side of the shaft 12 protrudes below the bearing 13 . A portion of the shaft 12 protruding below the bearing 13 is arranged inside the small diameter portion 1152 .

The motor 10 includes a retainer ring 19 that prevents the shaft 12 from coming off. The retaining ring 19 is sandwiched and fixed between the lower end surface of the bearing 13 and the bottom surface of the bearing holding portion 1151 . The retainer ring 19 has an annular shape, and the shaft 12 penetrates it. In other words, the retainer ring 19 faces the retainer groove 121 of the shaft 12 in the axial direction. The inner diameter of the through hole of the retaining ring 19 is larger than the outer diameter of the retaining groove 121 . Furthermore, the inner diameter of the through hole of the retainer ring 19 is smaller than the outer diameter of the portion of the shaft 12 vertically adjacent to the retainer groove 121 . Therefore, when the shaft 12 moves upward, the side wall of the retaining groove 121 contacts the retaining ring 19 in the axial direction. As a result, the shaft 12 is axially retained.

<3.3 Structure of Magnetic Attraction Unit 16>
As described above, since the outer surface of the shaft 12 and the inner surface of the bearing 13 are lubricated with oil, the shaft 12 can easily move not only in the circumferential direction but also in the axial direction with respect to the bearing 13 . Therefore, the motor 10 includes a magnetic attraction portion 16 that suppresses upward movement of the shaft 12 . Details of the magnetic attraction portion 16 will be described below with reference to the drawings. FIG. 4 is an enlarged cross-sectional view of a portion of the housing where the tip holder and the attraction magnet are arranged. FIG. 5 is a cross-sectional perspective view of a longitudinal section of the tip holder, the attraction magnet and the thrust plate. FIG. 6 is an exploded perspective view of the tip holder, attraction magnet and thrust plate.

As shown in FIGS. 4 to 6, the magnetic attraction section 16 includes a tip holder 161, an attraction magnet 162, and a thrust plate 163. As shown in FIG. The tip holder 161 has a bottom portion 165 , a tubular portion 166 and a flange portion 167 . The bottom portion 165 is disk-shaped and perpendicular to the central axis J. As shown in FIG. Although the bottom portion 165 has a disc shape here, it is not limited to a disc shape, and may have a polygonal shape when viewed from the axial direction. That is, the bottom portion 165 has a plate shape extending radially from the central axis J. As shown in FIG. The bottom portion 165 can have a shape that matches the shape of the attraction magnet 162 that is housed inside. The cylindrical portion 166 has a cylindrical shape extending upward along the central axis J from the radial outer edge of the bottom portion 165 . That is, the cylindrical portion 116 extends upward from the radial outer edge of the bottom portion 165 . The flange portion 167 has an annular shape extending radially outward from the upper end portion of the tubular portion 166 . That is, the flange portion 167 extends radially outward from the upper end portion of the cylindrical portion 166 . Note that the flange portion 167 is not limited to an annular shape.

The bottom portion 165 of the tip holder 161, the cylindrical portion 166, and the flange portion 167 are a single member. That is, the bottom portion 165, the tubular portion 166 and the flange portion 167 are a single member. The tip holder 161 is manufactured by, for example, pressing or drawing a metal plate. An example of the metal plate forming the tip holder 161 is an iron plate. Since the tip holder 161 is formed by pressing a metal plate, the tip holder 161 can be easily manufactured.

When the chip holder 161 is manufactured by press-working a metal plate, the metal plate is placed in a die and the bottom 165 is pushed into the die with a punch. At this time, stress concentrates on the connecting portion of the bottom portion 165 and the tubular portion 166 . In order to suppress the influence of this stress on the bottom portion 165 as a whole, a tool having an annular surface for pressing the metal plate is used. Accordingly, a bottom upper surface 1650 that is the upper surface of the bottom 165 includes a first surface 1651 and a second surface 1652 .

The first surface 1651 is deformed by stress and residual stress during press working. On the other hand, since the stress is used for deformation of the first surface 1651, it is difficult to be transmitted to the second surface 1652, and the second surface 1652 is substantially not deformed. Therefore, the second surface 1652 is a plane perpendicular to the central axis J. As shown in FIG. That is, at least a portion 1652 of the bottom portion upper surface 1650, which is the upper surface of the bottom portion 165, is perpendicular to the central axis J. As shown in FIG. To explain further, at least the second surface 1652 is perpendicular to the central axis J.

As shown in FIG. 4 , the first surface 1651 is located at the radially outer edge of the bottom portion 165 . The first surface 1651 is connected to the lower end portion of the tubular portion 166 . The first surface 1651 is annular. Also, the second surface 1652 is arranged radially inward of the first surface 1651 . Since the first surface 1651 is deformed by force applied during press working, it becomes thinner than the original metal plate. On the other hand, the second surface 1652 does not receive a large force and is not deformed, so it has substantially the same thickness as the original metal plate. Therefore, the second surface 1652 is positioned above the first surface 1651 . That is, the second surface 1652 is arranged above the first surface 1651 . In addition, since the first surface 1651 is thinner than the second surface 1652, the metal plate before press working may be processed separately. In this embodiment, the lower surface of the attraction magnet 162 contacts the second surface 1652 of the bottom upper surface 1650 . Therefore, in the chip holder 161 , the second surface 1652 is required to have higher machining accuracy than the first surface 1651 . For example, since the flatness of the second surface 1652 of the bottom upper surface 1650 may be set smaller than the flatness of the first surface 1651 when the chip holder 161 is pressed, the chip holder 161 can be manufactured easily.

The attraction magnet 162 has a cylindrical shape, and the upper surface 1621 and the lower surface 1622 are perpendicular to the center line of the cylinder. In other words, top surface 1621 and bottom surface 1622 are perpendicular to the centerline and parallel to each other. The attraction magnet 162 has magnetic poles in which an upper surface 1621 and a lower surface 1622 are different in the axial direction. The attraction magnet 162 is housed inside the cylindrical portion 166 . The tip holder 161 is made of iron here, and is made of a magnetic material. Therefore, the attracting magnet 162 has its lower surface 1622 fixed to the second surface 1652 by magnetic force. Furthermore, a part of the circumferential outer surface of the attraction magnet 162 contacts and is fixed to the inner surface of the cylindrical portion 166 by magnetic force. That is, the chip holder 161 accommodates the attraction magnet 162 . At least a portion of the radially outer surface of the attraction magnet 162 contacts the radially inner surface of the cylindrical portion 166 .

The axial length of the attraction magnet 162 is shorter than the axial length of the tubular portion 166 . Therefore, the upper surface 1621 of the attraction magnet 162 is located below the upper end of the tubular portion 166 . That is, the attraction magnet 162 is housed inside the cylindrical portion 166 . As a result, the cylindrical portion 166 functions as a back yoke of the attraction magnet 162 and strengthens the magnetic force of the attraction magnet 162 .

The lower surface 1622 of the attraction magnet 162 contacts at least a portion 1652 of the bottom upper surface 1650 . As a result, the center line of the attraction magnet 162 is parallel to the central axis J. As shown in FIG. In addition, the fact that the center line is parallel to the central axis J includes the case where the center line overlaps with the central axis J. Also, the upper surface 1621 of the attraction magnet 162 is orthogonal to the central axis J. As shown in FIG. In this embodiment, the lower surface 1622 of the attraction magnet 162 contacts the second surface 1652 of the bottom upper surface 1650 .

The thrust plate 163 is arranged above the upper surface 1621 of the attraction magnet 162 . In this embodiment, the thickness of the thrust plate 163 is smaller than the thickness of the tubular portion 166 . The thickness of the thrust plate 163 may be such that the magnetic flux from the upper surface 1621 of the attraction magnet 162 can pass therethrough and the lower end of the shaft 12 can be pulled. An upper surface 1621 of the attraction magnet 162 axially faces the lower convex portion 122 of the shaft 12 with the thrust plate 163 interposed therebetween. That is, the attraction magnet 162 has a columnar shape and is arranged to face the lower end surface 122 of the shaft 12 in the axial direction.

As a result, the lower surface of shaft 12 is attracted by the magnetic force of attraction magnet 162 , and the lower surface of shaft 12 contacts thrust plate 163 . That is, the shaft 12 is sucked downward. At this time, the lower convex portion 122 of the shaft 12 is located below the upper surface of the flange portion 167 . That is, the outer peripheral surface of the shaft 12 faces the inner peripheral surface of the tubular portion 166 in the radial direction. As a result, the magnetic flux from the attraction magnet 162 is transmitted to the lower end surface of the shaft 12 through the tubular portion 166 . Therefore, the attractive force of the attractive magnet 162 that attracts the shaft 12 downward can be increased. Therefore, when the motor 10 rotates, it is possible to prevent the shaft 12 from floating upward due to buoyancy, and the operating efficiency of the motor 10 can be improved.

Then, the shaft 12 is attracted by the attraction magnet 162 and rotates while the lower surface is in contact with the thrust plate 163 . Note that the thrust plate 163 may be made of a magnetic material. In this case, it is possible to increase the force of attracting the shaft 12 by the magnetic force of the attraction magnet 162 .

In the tip holder 161 , the flange portion 167 is fixed inside the housing 112 . That is, at least part of the flange portion 167 is fixed inside the housing 112 . The tip holder 161 is thereby held by the housing 112 . The base portion 11 is a molded body of resin, and the housing 112 is also molded of resin. The flange portion 167 is covered with the resin that forms the housing 112 . That is, the housing 112 is made of resin, and at least a portion of the flange portion 167 is covered with resin.

As a method for arranging the flange portion 167 inside the resin, for example, insert molding can be used. A chip holder 161 is attached to a mold for molding the base portion 11 . Then, the space where at least the flange portion 167 of the chip holder 161 is arranged is filled with resin. The filled resin is cured and the base portion 11 is molded. The tip holder 161 is thereby fixed to the housing 112 . By doing so, it is possible to fix the chip holder 161 to the housing 112 and to the base portion 11 by one resin molding. The chip holder 161 can be easily fixed to the housing 112, and the motor 10 can be manufactured easily.

In this embodiment, the entire flange portion 167 of the chip holder 161 is covered with resin. However, if the chip holder 161 can be firmly fixed, part of the flange portion 167 may be covered with resin. Conversely, what is covered with the resin is not limited to the flange portion 167, and the outer surfaces of the bottom portion 165 and the cylindrical portion 166 may be covered with the resin. In addition, in the chip holder 161, the flange portion 167 has an annular shape, that is, has a circular outer shape when viewed in the axial direction, but is not limited to this. For example, polygonal shapes such as oval, square, and rhombus may be used.

By providing the magnetic attraction portion 16 as described above, the assembly of the motor 10 is facilitated. Also, the tubular portion 166 functions as a back yoke for the attraction magnet 162 . As a result, the attraction force of the attraction magnet 162 that attracts the shaft 12 downward can be increased. Therefore, when the motor 10 rotates, it is possible to prevent the shaft 12 from floating upward due to buoyancy, and the operating efficiency of the motor 10 can be improved.

<3.3.1 Modification 1 of Magnetic Attraction Unit>
FIG. 7 is an enlarged cross-sectional view of another example of the magnetic attraction portion. A tip holder 161a shown in FIG. 7 differs from the flange portion 167 of the tip holder 161 in the shape of the flange portion 167a. The tip holder 161a has the same configuration as the tip holder 161 except for this point. Therefore, in the tip holder 161a, the same parts as in the tip holder 161 are denoted by the same reference numerals, and the detailed description of the same parts is omitted.

The attitude of the thrust plate 163 and the attitude of the shaft 12 follow the attitude of the attraction magnet 162 with respect to the direction perpendicular to the central axis J. As shown in FIG. As shown in FIG. 7, in the tip holder 161a, the flange portion 167a does not contact the shaft 12 main body. In addition, the thrust plate 163 and the attraction magnet 162 that are in direct contact with the shaft 12 are also not contacted. Therefore, unlike the second surface 1652 of the bottom portion 165 with which the lower surface 1622 of the attraction magnet 162 contacts, even if the flange portion 167a is inclined with respect to the direction orthogonal to the central axis J, the shaft 12 rotates in a posture of , has no effect. Therefore, the flange portion 167a does not have to be parallel to the direction orthogonal to the central axis J. As shown in FIG. 7 , in this modification, the flange portion 167 a is inclined with respect to the second surface 1652 of the bottom portion 165 . That is, the flange portion 167 a is inclined with respect to the bottom upper surface 1650 .

The chip holder 161a is manufactured by pressing a metal plate, like the chip holder 161 described above. As described above, in the tip holder 161 a , the angle accuracy required for the flange portion 167 a in the direction orthogonal to the central axis J is lower than the angle accuracy required for the second surface 1652 . Therefore, it is easy to manufacture the chip holder 161a.

In addition, as shown in FIG. 7, in the tip holder 161a, the flange portion 167a can be formed in a shape that extends upward as it extends radially outward. That is, the flange portion 167a slopes upward toward the radially outer side. With this shape, the bending angle of the flange portion 167a during press working can be made smaller than when the flange portion 167a is formed parallel to the second surface 1652 of the bottom portion 165 . As a result, the stress concentrated on the connecting portion between the flange portion 167a and the cylindrical portion 166 can be reduced. For example, when the flange portion 167a is fixed to the housing 112 by insert molding, the residual stress accumulated in the flange portion 167a of the tip holder 161a may be released depending on the temperature and other conditions. Even in this case, since the residual stress accumulated in the flange portion 167a is small, the stress acting on the housing 112 can be reduced.

<3.3.2 Modification 2 of Magnetic Attraction Portion>
FIG. 8 is a perspective view of still another example of the magnetic attraction part. The tip holder 161b shown in FIG. 8 differs from the flange portion 167 of the tip holder 161 in the shape of the flange portion 167b. The tip holder 161b has the same configuration as the tip holder 161 except for this point. Therefore, in the chip holder 161b, the same parts as in the chip holder 161 are denoted by the same reference numerals, and the detailed description of the same parts is omitted.

In the chip holder 161b shown in FIG. 8, the flange portion 167b includes flange protrusions 1671 in which adjacent portions in the circumferential direction are different in axial position. The upper surface of the flange protruding portion 1671 protrudes in the axial direction as compared with other portions of the upper surface of the flange portion 167b. In addition, the lower surface of the flange projection 1671 is recessed in the axial direction compared to other portions of the lower surface of the flange portion 167b. The flange portion 167b is undulating in the circumferential direction by having the flange projection portion 1671 . That is, at least a portion of the flange portion 167b has undulations in the circumferential direction.

When the flange portion 167b is arranged inside the resin of the housing 112, the flange convex portion 1671 acts as a resistance to restrict the movement of the tip holder 161b in the circumferential direction. In addition, in FIG. 7, as the flange convex portion 1671, an upwardly bulging portion is shown, but the present invention is not limited to this. For example, a downwardly bulging portion may be provided. Further, the flange portion 167b may have a shape in which an upwardly bulging portion and a downwardly bulging portion alternately appear periodically. In addition, the flange portion 167b may have an irregular uneven surface without being limited to the shape in which upwardly bulging portions and axially downwardly bulging portions alternately appear. Further, the thick portion and the thin portion of the flange portion 167b may be combined to form undulations on the upper and lower surfaces of the flange portion 167b. That is, at least a portion of either the upper surface or the lower surface of the flange portion 167b has undulations in the circumferential direction.

<3.3.3 Modified Example 3 of Magnetic Attraction Portion>
FIG. 9 is a perspective view of still another example of the magnetic attraction part. The cylindrical portion 166c of the tip holder 161c shown in FIG. The chip holder 161c has the same configuration as the chip holder 161 except for this point. Therefore, in the chip holder 161c, the same parts as in the chip holder 161 are denoted by the same reference numerals, and the detailed description of the same parts is omitted.

As shown in FIG. 9, the inner surface of the cylindrical portion 166c of the tip holder 161c is radially opposed to the outer surface of the shaft 12 over the entire circumference. It faces the inner peripheral surface with a gap in the radial direction. By configuring in this way, contact between the shaft 12 and the cylindrical portion 166c during rotation can be suppressed. Further, by making the axial length of the cylindrical portion 166c longer than that of the cylindrical portion 166, the contact area between the chip holder 161c and the resin forming the base portion is increased, and the chip holder 161c is firmly attached to the base portion 11. can be fixed.

<3.4 Structure of Circuit Board 30 and Board Holding Portion 17>
The base portion 11 has a plurality of substrate holding portions 17 . The circuit board 30 is held by the board holding portion 17 . Details of the circuit board 30 and the board holding portion 17 will now be described with reference to the drawings. FIG. 10 is a plan view of the base to which the circuit board is attached. FIG. 11 is an enlarged perspective view of the base portion with the circuit board removed. FIG. 12 is a cross-sectional perspective view enlarging the vicinity of the substrate holding portion.

As shown in FIG. 10 , the circuit board 30 is held by the board holding portion 17 provided on the plate portion 111 of the base portion 11 . The circuit board 30 is arranged on a board mounting portion 116 which is a region of the plate portion 111 radially outside the housing 112 . A portion of the housing 112 adjacent to the board mounting portion 116 is provided with a flat cutout surface 1121 . The cutout surface 1121 is a surface perpendicular to the radial direction.

Here, the circuit board 30 will be described. The circuit board 30 has an inner flat surface 301 and an outer flat surface 302 . The inner flat surface 301 and the outer flat surface 302 are flat surfaces, and the inner flat surface 301 and the outer flat surface 302 extend in a direction perpendicular to the radial direction. When the circuit board 30 is attached to the board attachment portion 116 , the inner flat surface 301 is a side surface on the side of the central axis J and radially faces the notch surface 1121 of the housing 112 . When the circuit board 30 is arranged on the board mounting portion 116 , the inner flat surface 301 is aligned with the cutout surface 1121 . Thereby, the circuit board 30 can be easily attached to the board holding portion 17 . In addition, the circuit board 30 can be placed closer to the central axis J. Further, the outer flat surface 302 is the side surface of the circuit board 30 opposite to the central axis J. As shown in FIG. Note that in this embodiment, the inner flat surface 301 and the outer flat surface 302 are parallel. In plan view, the length of the inner flat surface 301 in the direction orthogonal to the central axis is longer than the outer flat surface 302 . The inner flat surface 301 and the outer flat surface 302 are connected by a curved surface.

The circuit board 30 has a board through-hole 303 penetrating in the axial direction. The circuit board 30 is provided with two board through holes 303 . The base portion 11 has a plurality of bosses 117 extending upward from the upper surface. The base portion 11 is provided with two bosses 117 . A boss 117 penetrates through the substrate through-hole 303 . This restricts the circumferential and radial movement of the circuit board 30 . In order to limit the movement of the circuit board 30 in the circumferential direction and radial direction, it is preferable that at least two board through holes 303 and bosses 117 are provided.

Further, as shown in FIG. 10 , the upper surface of the circuit board 30 is provided with a connection portion 31 , an external connection portion 32 and a detection portion 33 . Also, the circuit board 30 has a wiring pattern formed of a conductive material such as aluminum or copper. The connection portion 31 and the external connection portion 32 are part of the pattern wiring. That is, the connection portion 31 and the external connection portion 32 are connection terminals. A lead wire 146 (see FIG. 17 and the like, which will be described later) drawn from a coil 143 described later is connected to the connection portion 31 . By connecting the connection portion 31 and the lead wire 146 , current from the driving circuit can be supplied to the coil 143 .

For example, a lead wire Wr used for connection with an external device such as an external power source is connected to the external connection portion 32 . The lead wire Wr connected to the external connection portion 32 is hooked on the lead wire lead-out portion 1131 and then led out to the outside. The detector 33 includes a sensor mounted on the upper surface of the circuit board 30 and detects rotation of the rotor 15 . As a sensor for detecting the rotation of the rotor 15, for example, a Hall element or the like can be used. The detector 33 is preferably arranged near the rotor 15 . Therefore, in the circuit board 30 , the detection section 33 is arranged radially inward, that is, on the inner flat surface 301 side.

The circuit board 30 is held by the board holding part 17 after being placed on the board mounting part 116 of the plate part 111 . Thereby, the circuit board 30 is fixed to the board mounting portion 116 . Next, the details of the substrate holding portion 17 will be described.

As shown in FIGS. 10 to 12 , the board holding portion 17 includes a first extension portion 171 , a second extension portion 172 , a connecting portion 173 and a claw portion 174 . The substrate holding portion 17 is provided on the base portion 11 and is made of the same material as the base portion 11 .

The first extension portion 171 extends downward from the lower surface of the base portion 11 . The base portion 11 has a base through hole 118 penetrating through the base portion in the vertical direction. The base through hole 118 has a rectangular shape when viewed from the axial direction. The first extension portion 171 has a tubular shape with a rectangular cross section that extends downward from all four sides of the rectangular shape forming the base through hole 118 . Thus, the strength of the first extension portion 171 can be increased by being formed in a cylindrical shape. If sufficient strength can be obtained, the first extension portion 171 may have a wall shape extending axially downward from the edge portion of one side of the base through-hole 118 instead of the cylindrical shape.

The second extension portion 172 extends from the lower side to the upper side of the base portion 11 in the base through hole 118 and faces the first extension portion 171 with a gap therebetween. The second extension portion 172 passes through the base through-hole 118 from below to above.

The connecting portion 173 connects the lower portion of the first extension portion 171 and the lower portion of the second extension portion 172 . By extending the first extension portion 171 downward once and then connecting it to the second extension portion 172 via the connecting portion 173 at its tip, the axial length of the second extension portion 172 can be increased. As a result, it is possible to suppress the deformation angle of the second extension portion 172 from increasing when the circuit board 30 is attached, and reduce the concentration of stress on the second extension portion 172 . For example, even when a thick circuit board 30 is used, the distance from the upper surface of the base portion 11 to the upper ends of the claw portions 174 does not need to be increased because the base portion 11 is once extended downward. As a result, the board holding portion 17 can stably hold the circuit board 30 while preventing the motor 10 from increasing in size.

The length of the second extension portion 172 is shorter than the length of the connecting portion 173 in the longitudinal direction of the base through-hole 118 . That is, the width of the second extension portion 172 is smaller than the width of the connecting portion 173 . By doing so, the second extension portion 172 is more easily deformed than the connecting portion 173 . Although the connecting portion 173 is connected to three sides of the first extension portion 171, the connecting portion 173 is not limited to this, and may be connected to at least a portion of the connecting portion. In the substrate holding portion 17, the connection portion 173 protrudes from the wall portion forming the long side of the first extension portion 171 and also connects the wall portion adjacent to the wall portion. That is, the connecting portion 173 connects one long side and both short sides of the first extension portion 171 . Thereby, the strength of the first extension portion 171 and the connecting portion 173 can be increased.

The claw portion 174 extends in a direction intersecting the central axis J from the upper end of the second extension portion 172 . In addition, in the present embodiment, the claw portion 174 extends from the upper end of the second extension portion 172 toward the side opposite to the connecting portion 173, but is not limited to this. For example, the claw portion 174 may extend from the upper end of the second extension portion 172 toward the connecting portion 173 side. The claw portion 174 includes a claw portion lower surface 1741 and a claw portion upper surface 1742 . The claw portion lower surface 1741 is the lower surface of the claw portion 174 and contacts the upper surface of the circuit board 30 . That is, at least a portion of the lower surface of claw portion 174 contacts the upper surface of circuit board 30 . The claw portion lower surface 1741 intersects with the central axis J. As shown in FIG. The claw portion lower surface 1741 is arranged above the upper surface of the board mounting portion 116 by the thickness of the circuit board 30 . In addition, in the claw portion 174, the claw portion lower surface 1741 is a surface orthogonal to the central axis J, but is not limited to this. Further, the claw portion lower surface 1741 may be positioned above the upper surface of the board mounting portion 116 by the thickness of the circuit board 30 . By doing so, a space is provided between the circuit board 30 and the lower surface 1741 of the claw portion, and the mounting of the circuit board 30 is facilitated.

The claw portion upper surface 1742 is the upper surface of the claw portion 174 and is positioned above the claw portion lower surface 1741 . The top surface 1742 of the claw portion is an inclined surface that faces downward in a direction away from the first extension portion 171 .

Then, as shown in FIG. 10 , the base portion 11 has three substrate holding portions 17 . Of the three board holding parts 17, two board holding parts 17 hold the inner flat surface 301 side of the circuit board 30, and one board holding part 17 holds the outer flat surface 302 side of the circuit board 30. Hold. In the following description, the substrate holding portion 17 holding the inner flat surface 301 side will be referred to as the inner substrate holding portion 17m, and the substrate holding portion 17 holding the outer flat surface 302 side will be referred to as the outer substrate holding portion 17n as necessary. distinguish as

A side surface of the inner substrate holding portion 17m where the claw portion 174 extends faces the inner flat surface 301 in a direction intersecting the central axis J. As shown in FIG. Further, the side surface on which the claw portion 174 of the second extension portion 172 of the outer substrate holding portion 17n extends faces the inner flat surface 301 in the direction intersecting the central axis J. As shown in FIG.

In this manner, the inner flat surface 301 side of the circuit board 30 is held by the two inner board holding portions 17m, and the outer flat surface 302 side of the circuit board 30 is held by the outer board holding portions 17n. movement away from the central axis J is restricted.

Next, attachment of the circuit board 30 to the board attachment portion 116 will be described. The boss 117 is passed through the board through hole 303 of the circuit board 30 . Thereby, the circuit board 30 is positioned with respect to the board mounting portion 116 in the circumferential direction and the radial direction. By moving the circuit board 30 downward, the claw upper surface 1742 of the inner board holding portion 17m comes into contact with the lower edge of the inner flat surface 301 . Also, the top surface 1742 of the claw portion of the outer substrate holding portion 17n comes into contact with the lower edge portion of the outer flat surface 302 . When the circuit board 30 is moved further downward, the claw upper surface 1742 of the inner board holding portion 17m is pushed by the inner flat surface 301, and the second extension 172 is elastically deformed toward the first extension 171 side. Further, the upper surface 1742 of the claw portion of the outer substrate holding portion 17n is pushed by the outer flat surface 302, and the second extension portion 172 is elastically deformed toward the first extension portion 171 side.

When the lower surface of the circuit board 30 contacts the upper surface of the board mounting portion 116, the claw portions 174 of the inner board holding portion 17m and the outer board holding portion 17n are positioned above the upper surface of the circuit board 30. As a result, the elastically deformed second extension portion 172 returns to its original position, and the claw portion lower surface 1741 of the claw portion 174 comes into contact with the upper surface of the circuit board 30 . As a result, the upward movement of the circuit board 30 is restricted by the inner board holding portion 17m and the outer board holding portion 17n.

By attaching the circuit board 30 to the board attachment portion 116, movement of the circuit board 30 in the axial, radial and circumferential directions is restricted. In this state, the lead wire 146 (see FIG. 17 described later) is fixed to the connection portion 31 and the lead wire Wr is fixed to the external connection portion 32 .

The lead wire Wr connected to the external connection portion 32 is connected to an external device such as an external power supply. If the lead wire Wr becomes loose, it is necessary to increase the distance between the lead wire Wr and the rotor 15 in order to prevent contact between the lead wire Wr and the rotor 15 . However, increasing the distance between the lead wire Wr and the rotor 15 increases the size of the motor 10 . In order to miniaturize the motor 10, it is preferable that the lead wire Wr is pulled out while being tensioned to some extent. In this embodiment, the lead wire Wr is pulled out by being hooked on the lead wire lead-out portion 1131 . Therefore, when drawing out the lead wire Wr, the circuit board 30 is pulled in the direction in which the lead wire Wr extends. In this embodiment, the direction in which the external connection portion 32 is arranged, that is, the direction in which the lead wire Wr extends, intersects the direction in which the claw portions 174 of the inner substrate holding portion 17m extend and the direction in which the claw portions 174 of the outer substrate holding portion 17n extend. It is the direction to do so. By providing the external connection portion 32 in this way, even if the circuit board 30 is pulled by the lead wire Wr, deformation of the second extension portions 172 of the inner board holding portion 17m and the outer board holding portion 17n can be suppressed. As a result, the circuit board 30 can be firmly held by the inner board holding portion 17m and the outer board holding portion 17n.

Note that the board mounting portion 116 includes two inner board holding parts 17m and one outer board holding part 17n, but is not limited to this. For example, three or more substrate holders 17 may be provided. Further, when the positioning accuracy of the bosses 117 is high, the circuit board 30 is less likely to rattle, so the number of the board holding portions 17 may be one. In this case, it may be arranged on the inner flat surface 301 side or may be arranged on the outer flat surface 302 side. A portion of the circuit board 30 other than the flat inner surface 301 and the flat outer surface 302 may be held. At this time, the side surface facing the substrate holding portion 17 is preferably flat.

<3.5 Configuration of Rotor 15>
The rotor 15 has a rotor magnet 151 and a magnet holder 152 . The rotor magnet 151 has a cylindrical shape, and N-pole magnetic pole faces and S-pole magnetic pole faces are alternately arranged in the circumferential direction. As the rotor magnet 151, for example, a cylindrical body integrally formed of a resin containing magnetic powder is magnetized alternately with N poles and S poles in the circumferential direction. . Also, the rotor magnet 151 may be composed of a plurality of magnet pieces. In this case, the N poles and S poles of the magnet may be arranged alternately in the circumferential direction.

The magnet holder 152 is made of a magnetic material, and the rotor magnet 151 is fixed to its inner surface. The magnet holder 152 includes a lid portion 153 and a holder tubular portion 154 . The lid portion 153 has an annular shape. The holder tubular portion 154 extends downward from the radial outer edge of the lid portion 153 . The magnet holder 152 is fixed inside the tubular hub portion 223 of the impeller 20 . Thereby, the center of the rotor magnet 151 overlaps with the central axis J. As shown in FIG.

<3.6 Configuration of Stator 14>
Next, details of the stator 14 will be described. FIG. 13 is a perspective view of the stator as seen from below. 14 is a bottom view of the stator shown in FIG. 13. FIG. As shown in FIG. 3 and the like, the stator 14 is fixed to the housing 112 . As shown in FIGS. 13 and 14 , stator 14 includes stator core 141 , insulator 142 , and coil 143 . The stator core 141 is a laminate in which electromagnetic steel sheets are laminated in the axial direction (vertical direction in FIG. 3). In addition, the stator core 141 is not limited to a laminated body in which electromagnetic steel sheets are laminated, and may be a single member such as firing powder or casting.

Stator core 141 has an annular core back 144 and a plurality of teeth 145 . It is fixed to the inner surface of the annular core back 144 . Core back 144 and housing 112 may be fixed relative to each other.

A plurality of teeth 145 are radially formed extending radially outward from the outer peripheral surface of core back 144 toward magnets (not shown) of rotor 15 . That is, teeth 145 extend radially outward from core back 144 . Thereby, a plurality of teeth 145 are arranged in the circumferential direction. The coil 143 is configured by winding a conductive wire around each tooth 145 via an insulator 142 .

The insulator 142 is made of, for example, resin, and covers at least the teeth 145 . Insulator 142 also insulates stator core 141 including teeth 145 from coil 143 . Insulator 142 is not limited to resin, and a wide variety of materials that can insulate stator core 141 and coil 143 can be used.

As described above, the coil 143 is formed by winding a conductive wire around the tooth 145 with the insulator 142 interposed therebetween. The conducting wire forming the coil 143 has a winding start portion and a winding end portion. A lead wire 146 drawn out from the coil 143 is a winding start portion and a winding end portion of the conducting wire. The lead wire 146 is connected to the connection portion 31 of the circuit board 30 . The wire is wound over several coils 143 . Therefore, the stator 14 has two lead wires 146 . In this embodiment, since the motor 10 is a single-phase motor, two lead wires 146 are provided, but the present invention is not limited to this. For example, if the motor 10 is a three-phase motor, three lead wires 146 may be provided.

The connection portion 31 is connected to a drive circuit (not shown) mounted on the circuit board 30 , and current is supplied from the drive circuit to the coil 143 via the lead wire 146 . Motor 10 is a brushless motor. By supplying electric currents to the plurality of coils 143 at predetermined timings, the coils 143 and the rotor magnet 151 attract or repel each other, thereby rotating the rotor 15 . The stator 14 includes a guide portion 18 that guides lead wires 146 drawn out from the coils 143 .

<3.7 Configuration of Guide Unit 18>
Next, details of the guide portion 18 will be described with reference to the drawings. FIG. 15 is a perspective view of the enlarged guide portion viewed from above. FIG. 16 is a perspective view of an enlarged guide portion viewed from below. FIG. 17 is an enlarged cross-sectional view of the stator and the base including the guides.

As shown in FIGS. 15, 16, and 17, the guide portion 18 is arranged below the insulator 142. As shown in FIGS. The guide portion 18 is arranged radially outward of the coil 143 . The guide portion 18 is made of the same member as the insulator 142 . The guide portion 18 includes a first wall portion 181 , a second wall portion 182 and a bent portion 183 . The first wall portion 181 extends downward from the lower surface of the insulator. The first wall portion 181 extends along the circumferential direction. Both circumferential ends of the first wall portion 181 are provided with curved surfaces 184 . A radially outer surface 1811 of the first wall portion 181 is smoothly connected to a radially inner surface 1812 . In other words, the curved surface 184 is a differentiably connected curved surface. The curved surface 184 itself is also a differentiable curved surface.

The bent portion 183 connects to the lower end portion of the first wall portion 181 and extends radially outward. The bent portion 183 is orthogonal to the central axis J here. The bent portion 183 axially faces the base portion 11 and the circuit board 30 across a gap. The second wall portion 182 connects to the radial outer edge of the bent portion 183 and extends upward. The first wall portion 181 and the second wall portion 182 face each other in the radial direction with a gap 185 interposed therebetween. The radial thickness of the first wall portion 181 is greater than the radial thickness of the second wall portion 182 . A force may be applied to the first wall portion 181 by winding the lead wire 146 . By configuring in this way, the strength of the first wall portion 181 can be improved.

The lead wire 146 contacts the radial outer surface 1811 and the radial inner surface 1812 of the first wall portion 181 . In this embodiment, the lead wire 146 is wound around the first wall portion 181 of the guide portion 18 for one or more turns. At this time, the lead wire 146 contacts the curved surface 184 . As a result, when the lead wire 146 crosses between the radial outer surface 1811 and the radial inner surface 1812, stress is less likely to concentrate, and the load on the lead wire 146 can be reduced. The tip of the lead wire 146 wound around the first wall portion 181 is fixed to the connecting portion 31 provided on the circuit board 30 . Soldering can be used to fix the lead wire 146 to the connecting portion 31 .

A lead wire 146 drawn out from the coil 143 is temporarily wound around the guide portion 18 and connected to the connection portion 31 . During assembly of motor 10 , pre-assembled stator 14 is secured to housing 112 . Coils 143 are formed by winding conductive wires around teeth 145 of stator 14 before being fixed to housing 112 . At this time, since the lead wire 146 is wound around the guide portion 18, the lead wire 146 and the coil 143 are less likely to loosen. This facilitates the work in manufacturing the motor 10 . In addition, by winding the lead wire 146 around the guide portion 18 , the force acting on the lead wire 146 can be received by the guide portion 18 . As a result, it is possible to prevent the lead wire 146 from moving when it is fixed to the connecting portion 31 .

When the lead wire 146 and the connection portion 31 are fixed, the lead wire 146 may be pulled in the direction in which the connection portion 31 is arranged. In other words, a downward force may act on the lead wire 146 . The bent portion 183 connects to the lower end portion of the first wall portion 181 and extends radially outward. Therefore, the lead wire 146 contacts the upper surface of the bent portion 183 even if a downward force acts. That is, it is possible to suppress the lead wire 146 from moving when it is fixed to the connecting portion 31 .

The guide portion 18 is arranged at a position that partially faces the rotor magnet 151 in the axial direction. A lead wire 146 guided by the guide portion 18 is arranged below the rotor 15 and spaced from the rotor 15 . Therefore, contact between lead wire 146 and rotor 15 can be suppressed.

In addition, the connection portion 31 is positioned radially outward of the radial outer edge of the bent portion 183 . Furthermore, the connecting portion 31 is positioned radially outward of the magnet holder 152 of the rotor 15 . By arranging in this way, the lead wire 146 and the connection portion 31 can be fixed in a state where the rotor 15 and the fixed shaft 12 are attached to the base portion 11, and the working efficiency can be improved. Further, for example, even when the shaft 12, the rotor 15, and the impeller 20 are fixed by insert molding, the distance between the connecting portion 31 and the insulator 142 can be increased. Therefore, it is possible to easily arrange a jig or the like for fixing the lead wire 146 and the connection portion 31, and it is possible to improve work efficiency.

In addition, although the insulator 142 is provided with two guide portions 18, the present invention is not limited to this. For example, when a plurality of lead wires 146 can be wound, the number of guide portions 18 may be one. Further, for example, when there are a plurality of lead wires 146 , the number of guide portions 18 may be the same as the number of lead wires 146 .

<3.7.1 Modified example of guide part>
FIG. 18 is an enlarged cross-sectional view of the stator and the base including another example of the guide. As shown in FIG. 18, the guide portion 18a includes a first wall portion 181 and a bent portion 183. As shown in FIG. That is, the guide portion 18a has a configuration in which the second wall portion 182 is omitted from the guide portion 18, and other portions are the same as the guide portion 18. As shown in FIG. Therefore, portions of the guide portion 18a that are the same as those of the guide portion 18 are denoted by the same reference numerals, and detailed description of the same portions is omitted.

For example, when the lead wire 146 is wound around the first wall portion 181 multiple times to prevent the lead wire 146 from slipping, the loosening of the lead wire 146 can be suppressed even if the second wall portion 182 is omitted. Moreover, even if a downward force acts on the lead wire 146 , the lead wire 146 contacts the upper surface of the bent portion 183 . That is, it is possible to suppress the lead wire 146 from moving when it is fixed to the connecting portion 31 .

Next, a method for assembling the blower A will be described. In the blower A, the flange portion 167 of the chip holder 161 is fixed to the housing 112 by insert molding. The chip holder 161 opens upward, that is, toward the holding recess 115 of the housing 112 . A suction magnet 162 is inserted into the tip holder 161 . At this time, the lower surface 1622 of the attraction magnet 162 contacts the second surface 1652 of the bottom portion 165 of the tip holder 161 .

The lower surface 1622 and the second surface 1652 are fixed by magnetic force. At this time, a magnetic force also acts between the cylindrical portion 166 and the side surface of the attraction magnet 162 . As a result, part of the attraction magnet 162 comes into contact with the inside of the cylindrical portion 166 . An upper surface 1621 of the attraction magnet 162 is positioned below the flange portion 167 . That is, the attraction magnet 162 is accommodated in the cylindrical portion 166 . As a result, the tubular portion 166 functions as a back yoke of the attraction magnet 162 and can strengthen the magnetic force of the attraction magnet 162 . A thrust plate 163 is arranged on the upper surface of the attraction magnet 162 . The thrust plate 163 is housed inside the cylindrical portion 166 .

After inserting the retaining ring 19 into the retaining recess 115 , the bearing 13 is press-fitted into the retaining recess 115 from above the retaining ring 19 . As a result, the retainer ring 19 is sandwiched and fixed between the lower end of the bearing 13 and the bottom surface of the bearing holding portion 1151 .

The circuit board 30 is attached to the board attachment portion 116 of the base portion 11 . At this time, the circuit board 30 is fixed to the base part 11 by holding the vicinity of the inner flat surface 301 and the outer flat surface 302 with the board holding part 17 while allowing the bosses 117 to pass through the board through holes 303 of the circuit board 30 . . A lead wire Wr connected to an external power source is connected to the external connection portion 32 of the circuit board 30 fixed to the base portion 11 . The lead wire Wr is hooked on the lead wire lead-out portion 1131 of the arm portion 113 .

Then, an insulator 142 is attached to the stator core 141 , and a conducting wire is wound around teeth 145 via the insulator 142 to form a coil 143 . At this time, the lead wire 146 drawn from the coil 143 is wound around the guide portion 18 . At this time, the tip of the lead wire 146 is pulled out radially outward from the radial outer edge of the stator 14 .

Then, the core back 144 of the stator 14 is arranged outside the housing 112 and the stator 14 is attached to the base portion 11 . At this time, the stator 14 is fixed to the housing 112 . Then, the end portion of the lead wire 146 drawn out from the coil 143 is fixed to the connection portion 31 of the circuit board 30 by soldering. By arranging the connection portion 31 radially outside the stator 14 , the lead wire 146 can be easily fixed to the connection portion 31 .

The upper end of shaft 12 is fixed to boss 224 of impeller 20 . Then, the rotor 15 including the rotor magnet 151 and the magnet holder 152 is attached to the tubular hub portion 223 . Then, the shaft 12 is inserted into the holding recess 115 from above. At this time, the shaft 12 passes through the bearing 13 . Then, the lower convex portion 122 of the shaft 12 is pressed against the through hole of the retainer ring 19 and pushed. The through hole of the retainer ring 19 is smaller than the outer diameter of the shaft 12, but has a size that allows the lower end of the shaft 12 to pass therethrough when elastically deformed. Then, the retainer ring 19 is moved to a position radially overlapping the retainer groove 121 of the shaft 12 . At this time, the lower convex portion 122 contacts the thrust plate 163 . When the shaft 12 is attached to the bearing 13 , the radial outer surface of the stator 14 radially faces the inner surface of the rotor magnet 151 .

In the air blower A thus assembled, the shaft 12 is attached to the holding recess 115 of the housing 112 via the bearing 13, so that a radial gap is formed between the radial outer edge of the stator 14 and the rotor magnet 151. opposite. A magnetic force is generated between the coil 143 and the rotor magnet 151 by applying a current to the coil 143 via the lead wire 146 . A rotational force acts on the rotor 15 due to the attraction and repulsion of the magnetic force. As a result, the motor 10, that is, the shaft 12 rotates around the central axis J. As shown in FIG. Then, the impeller 20 fixed to the shaft 12 rotates to generate an airflow.

Although the embodiments of the present invention have been described above, various modifications and combinations of the embodiments are possible within the scope of the present invention.

INDUSTRIAL APPLICABILITY According to the present invention, it can be used as a motor for rotating an impeller of a blower.

A... Blower device 10... Motor 11... Base part 111... Plate part 112... Housing 1121... Notch surface 113... Arm part 1131... Lead wire extraction portion 114 Anti-vibration member 115 Holding recess 1151 Bearing holding portion 1152 Small diameter portion 116 Substrate mounting portion 117 Boss DESCRIPTION OF SYMBOLS 118... Base through-hole 12... Shaft 121... Groove 122... Lower surface convex part 13... Bearing 14... Stator 141... Stator core 142... Insulator, 143... Coil, 144... Core back, 145... Teeth, 146... Lead wire, 15... Rotor, 151... Rotor magnet, 152... Magnet holder, 153... Lid portion 154 Holder cylindrical portion 16 Magnetic attraction portion 161 Chip holder 161a Chip holder 161b Chip holder 161c Chip holder 162 Attraction magnet 1621 Upper surface 1622 Lower surface 163 Thrust plate 165 Bottom 1651 First surface 1652 Second surface 166 Cylinder portion 166c Cylinder portion 167 Flange portion 167a Flange portion 167b Flange portion 1671 Flange convex portion 17 Substrate holding portion 17m Inner board holding part 17n Outer board holding part 171 First extension 172 Second extension 173 Connecting part 174 Claw part 1741. Lower surface of claw portion 1742 Upper surface of claw portion 18 Guide portion 18a Guide portion 181 First wall portion 1811 Outer surface in radial direction 1812 Diameter Direction inner surface 182 Second wall portion 183 Bent portion 184 Curved surface 185 Gap 19 Retaining ring 20 Impeller 21 Impeller base 22 Impeller hub 220 Lower recessed portion 221 Hub top plate portion 222 Hub inclined portion 223 Hub tubular portion 224 Boss portion 225 ... Hole 23 ... Blade 24 ... Support frame 30 ... Circuit board 301 ... Inner flat surface 302 ... Outer flat surface 303 ... Substrate through hole 31 ... connection part, 32 ... external connection part, 33 ... detection part

Claims (11)

A motor having a rotor that rotates around a vertically extending central axis,
a shaft formed of a magnetic material and extending along the central axis;
a bearing that rotatably supports the shaft;
a housing located below the rotor and holding the bearing;
a columnar attraction magnet disposed axially facing the lower end surface of the shaft;
a tip holder held by the housing and containing the attraction magnet,
The tip holder is
a plate-shaped bottom extending radially from the central axis;
a cylindrical portion extending upward from a radial outer edge of the bottom portion;
a flange portion extending radially outward from the upper end portion of the cylindrical portion;
at least a portion of the flange portion is fixed inside the housing;
at least a portion of the top surface of the bottom portion, which is the top surface of the bottom portion, is orthogonal to the central axis;
The axial length of the attraction magnet is shorter than the axial length of the cylinder,
the lower surface of the attraction magnet is in contact with at least a portion of the upper surface of the bottom;
At least part of the radially outer surface of the attraction magnet is in contact with the radially inner surface of the cylinder, the housing is made of resin, and at least part of the flange is covered with the resin,
A motor in which a radial outer end portion of the flange portion is positioned outside a radial outer end portion of the bearing.
The bottom upper surface is
a first surface connected to the lower end of the cylindrical portion;
a second surface arranged radially inward of the first surface,
At least the second surface is orthogonal to the central axis,
2. A motor according to claim 1, wherein said second surface is positioned above said first surface. 3. The motor according to claim 1, wherein the axial lower end surface of the shaft is located axially lower than the upper surface of the flange portion. 4. The motor according to claim 3, wherein the outer peripheral surface of the shaft faces the inner peripheral surface of the cylindrical portion with a gap in the radial direction over the entire circumference. 5. The motor according to any one of claims 1 to 4, wherein the bottom portion, the cylindrical portion and the flange portion are a single member. The motor according to any one of claims 1 to 5, wherein the flange portion is inclined with respect to the upper surface of the bottom portion.
7. The motor according to claim 6, wherein the flange portion has an upward slope as it extends radially outward.
8. The motor according to any one of claims 1 to 7, wherein at least part of the flange portion has undulations in the circumferential direction.
9. The motor according to any one of claims 1 to 8, wherein at least a portion of one of the upper surface and the lower surface of the flange portion has undulations in the circumferential direction.
a motor according to any one of claims 1 to 9;
and an impeller fixed to the shaft.
a motor according to any one of claims 1 to 10;
and an impeller fixed to the shaft.

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