JP3434426B2 - Motor core, motor provided with the motor core and jig for coating the core - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor core having an insulating coating film on the surface of a core body, a motor including the motor core, and a jig used for coating the core body.

[0002]

2. Description of the Related Art Generally, a motor core used in a stator of a motor includes a core main body having a mounting hole, and the core main body includes an annular base portion provided with the mounting hole and a plurality of radial bases extending radially outward from the annular base portion. It has a teeth part. This core body has an insulating coating film on its surface,
The insulating coating film maintains the insulation between the coil wound around the teeth.

Such coating of the motor core is performed, for example, as shown in FIG. 12 from the viewpoint of workability and the like. That is, when coating the core body 2, first,
The elongated rod-shaped member 4 is inserted into the mounting hole 6 of the core body 2, and the rod-shaped member 4 holds a large number of core bodies 2 (only one is shown in FIG. 12). Next, the core body 2 held by the rod-shaped member 4 is transferred to the coating area, and while being held by the rod-shaped member 4, the core body 2 is coated with a paint by spraying or the like, and a coating film is formed on the surface of the core body 2. To form. Thereafter, the core body 2 having the coating film is heated and cooled to melt and fix the coating film on the surface thereof, thus forming the insulating coating film on the surface of the core body 2.

[0004]

However, in the prior art, the rod-shaped member 4 is inserted through the mounting holes 6 of each core body 2.
The core main body 2 is held by inserting, and the core main body 2 is coated with the core main body 2 held in this manner.
Therefore, as understood from FIG. 12, the outer peripheral surface and both end surfaces of the core body 2 can be painted, but the mounting hole 6 of the core body 2 cannot be painted, and the mounting hole 6 is not painted. There is a problem that the area rusts. More specifically, the motor core is attached to, for example, an annular mounting portion of the base plate when assembled to the motor. In this mounting to the annular mounting portion, when the mounting hole of the core body is configured to be mounted on the annular mounting portion over the entire area, the entire mounting hole of the core body is covered by the outer peripheral surface of the annular mounting portion. , Even if the mounting hole is not painted, the problem of rust does not occur. On the other hand, as the motor has become smaller and thinner in recent years, the annular mounting portion of the pace plate has become shorter, and the entire mounting hole of the core body cannot be mounted on the annular mounting portion. Only the lower end portion of is attached to the annular attachment portion. In such a configuration, most of the mounting holes of the core body are exposed, and a problem of rusting occurs in a region of the mounting hole protruding from the annular mounting portion.

To solve this problem, for example,
It is sufficient to paint the mounting holes of the core body in a separate process,
When the entire area of the mounting hole is covered with the insulating coating film as described above, the core body and the base plate are completely electrically insulated, and the core body cannot be electrically grounded to the base plate.

An object of the present invention is to reduce the size and thickness of a motor, to solve the rust problem, and to secure an electrical ground between the core body and the member to which the motor core is attached. It is to provide a provided motor.

Another object of the present invention is to provide a jig for coating a core, which is suitable for coating the inner peripheral surface of one end surface of the core body and the surface excluding one end portion of the mounting hole.

[0008]

According to one aspect of the present invention, a structure is formed by stacking a plurality of core plates.
Installed on the motor base plate
Comprising a core body having a tooth portion extending radially outward from the base portion and the base portion of the annular mounting holes are provided at intervals in the circumferential direction for one of the base of the core body
The inner periphery of the end face and one end of the mounting hole are the base of the motor.
Mounted directly on the annular shoulder provided on the base plate
In the motor core, the inner peripheral portion of the one end surface of the base portion and the one end portion of the mounting hole are exposed to the outside of the core plate , and the inner peripheral portion of the one end surface of the base portion and the one end portion of the mounting hole of the core main body are excluded. global surface is motor core, characterized in that is covered by the insulation coating film is provided.

In the motor core according to claim 1 of the present invention, the core body is exposed at the inner peripheral portion of the one end surface of the base portion and the one end portion of the mounting hole. Therefore, by mounting this portion on the motor, the core body and the motor side An electrical ground with is secured. Also, since this portion is not covered with the insulating coating film, by attaching the portion where the insulating coating film does not exist to the motor, only the portion corresponding to the thickness of this insulating coating film
The thickness of the core body, the radial length of the core body, the thickness of the base plate, etc. can be increased. Furthermore, since the inner surface of one end of the core body and the surface of the core body except one end of the mounting hole are covered with an insulating coating film, when the core body is assembled to the motor, the core body is not exposed to the outside. It also eliminates the rust problem of the core body.

According to another aspect of the present invention, a base plate, a rotor rotatable relative to the base plate, a rotor magnet mounted on the rotor, and a rotor magnet mounted on the base plate so as to face the rotor magnet. A motor including a stator, the stator including a motor core and a coil wound around the motor core, wherein the motor core is formed by stacking a plurality of core plates.
And the base play
Comprising a core body having a tooth portion extending radially outwardly from the annular base your <br/> and the base mounting holes are provided for mounting the bets at intervals in the circumferential direction, the core body
Inner peripheral portion of one end surface of the base portion and one end portion of the mounting hole
Is attached to the annular shoulder provided on the attachment part of the base plate.
Provided is a motor, which is directly mounted, wherein the entire surface of the core body except the inner peripheral portion of one end surface of the base portion and one end portion of the mounting hole is covered with an insulating coating film.

In the motor according to the second aspect of the present invention, since the inner peripheral portion of the one end surface of the core body and the one end portion of the mounting hole are directly attached to the base plate, electrical grounding between the core body and the base plate is ensured. To be done. Further, since this portion is not covered with the insulating coating film, the thickness of the core main body, the radial length of the core main body, the thickness of the base plate, etc. are increased by the amount corresponding to the thickness of the insulating coating film. It is also possible to reduce the size and thickness of the motor, and the design allowable range of the motor is increased. Further, since the surface of the core body other than the inner peripheral surface of the one end portion of the core body and the one end portion of the mounting hole is covered with the insulating coating film, the rust problem of the core body is eliminated.

According to another aspect of the present invention, when the core body having the mounting hole at the base is coated with paint ,
Retaining function to support the core body, and one end of the core body
The paint does not adhere to the inner peripheral surface and one end of the mounting hole.
For core coating with anti-sticking function to
A jig, a first tool for supporting one end portion of the core body, supports the other end portion of the core body, and the first
And a second tool for clamping the core body with the tool
Is configured, the first tool, said coating material at one end of the one end face in the peripheral portion and the mounting hole of the core body is configured in a shape not applied constitute the attachment prevention function, the second tool The core coating jig is provided with an opening communicating with the mounting hole so that the coating material can flow into the mounting hole of the held core body.

In the jig for coating a core according to claim 4 of the present invention, since the first tool has a shape in which the coating is not applied to the inner peripheral portion of the one end surface of the core body and one end portion of the mounting hole, No paint is applied to these parts of the body. Further, the second tool has an opening formed therein, and the paint flows through the opening into the mounting hole of the core body, so that the insulating coating film can also form the mounting hole of the core body.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a spindle motor which is an embodiment of a motor according to the present invention. The illustrated spindle motor includes a base plate 52. The base plate 52 has a circular plate body 54, an annular projecting wall 56 extends upward from the outer peripheral edge of the plate body 54, and a flange 58 projects radially outward from the upper end of the projecting wall 56. . The base plate 52 is attached to the base member by fixing the flange 58 to the base member (not shown) of the hard disk drive with mounting screws (not shown).

At the center of the plate body 54 of the base plate 52, there is provided an annular mounting portion 60 which projects somewhat upward, and one end of the shaft member 62 is fixed by press fitting into the hole of this annular mounting portion 60. The other end of the shaft member 62 extends upward from the plate body 54. The shaft member 62 includes
A hub 68 (constituting a rotor) is rotatably mounted via a pair of bearings 64, 66. The hub 68 has a cylindrical hub body 70, and at the lower end of the hub body 70,
A disk mounting portion 72 is provided that projects radially outward. A magnetic disk 74, on which information is written, is placed on the disk mounting portion 72, and one or more magnetic disks 74 are mounted on the outer side of the hub body 70 at intervals in the vertical direction (only one is shown in FIG. 1).

An annular yoke member 76 is attached to the lower end of the disk mounting portion 72, and the inner peripheral surface of the yoke member 76 is
An annular rotor magnet 78 is attached. A stator 80 is arranged to face the rotor magnet 78,
The stator 80 is attached to the mounting portion 60 of the plate body 54. The stator 80 is composed of a motor core 82 and a coil 84 wound around the motor core 82. The motor core 82 will be described in detail later. With this configuration, when a predetermined current is sent to the coil 84, the rotor magnet, and thus the hub 68, rotates in a predetermined direction due to the mutual magnetic action of the stator 80 and the rotor magnet 78.

Next, referring to FIG. 1 and FIG. 2, the motor core 82 will be described.
Has a core body 88 formed by stacking a plurality of core plates 86. This core body 8
The shape of 8 is substantially the same as that of the conventional core body shown in FIG. 12, and has an annular base portion 87 and a plurality of teeth portions 89. A circular mounting hole 90 is formed in the base 87,
The mounting hole 90 is mounted on the mounting portion 60 of the plate body 54 as described later. The plurality of tooth portions 89 are provided at equal intervals in the circumferential direction, project outward in the radial direction from the base portion 87, and the coils 84 are wound around the plurality of tooth portions 89 as required.

Most of the core body 88 is an insulating coating film 9.
Covered by two. As shown in FIG. 2, the inner peripheral portion of one end surface (lower end surface in FIG. 2) of the core body 88 and one end portion of the mounting hole 90 are not covered with the insulating coating film 92, but other surfaces of the core body 88. Is covered with an insulating coating film 92 having a predetermined thickness. In such a motor core 82, the portion of the core body 88 where the insulating coating film 92 does not exist is the mounting portion 6 of the base plate 52 in FIG.
0 is attached to the outer peripheral surface of the upper end portion. In the present embodiment, an annular shoulder portion 60a corresponding to the shape of the inner peripheral portion of the one end portion of the core body 88 is provided at the upper end portion of the mounting portion 60, and the one end portion of the core body 88 is provided on the shoulder portion 60a. Mounted. As described above, since the inner peripheral portion of the one end surface of the core body 88 and the one end portion of the mounting hole are directly attached to the base plate 52 without the insulating coating film 92, the core body 88 and the base plate 52 are not attached. An electrical ground with is secured. Further, since the insulating coating film 92 does not substantially exist between the core main body 88 and the base plate 52, the thickness of the core main body 88 and the radial direction of the core main body 88 are equal to the thickness of the insulating coating film 92. The length, the thickness of the base plate 52, and the like can be increased, and the motor can be downsized and thinned by the amount corresponding to the thickness of the insulating coating film 92, so that the design allowable range of the motor is large. Become. Since the portion of the core body 88 where the insulating coating film 92 does not exist is not exposed, the problem of rust does not occur. On the other hand, the surface of the core body 88 excluding the inner peripheral surface of the one end and the one end of the mounting hole 90 is covered with the insulating coating film 92, so that substantially the entire exposed portion is covered with the insulating coating film 92. The electrical insulation of this area is ensured and rust does not occur.

The coating of the core body 88 is performed by, for example, FIG.
It can be formed according to the steps shown in. Referring to FIG. 3, first, in step 1, the pretreatment of the core body 88 formed by stacking the core plates 86 is performed.

This is the pressing oil on the surface of the core body 88,
It is a step of removing deposits such as rust preventive oil that hinders stability and adhesion of the coating film. The core body 88 is heated by hot air convection at a temperature at which the deposits are not decomposed or carbonized and the core material is not oxidized. Heat treatment for a certain time in an infrared atmosphere furnace.

The core body 88 which has undergone the pretreatment process is cooled to room temperature and then powder coated in the electrostatic powder coating process of step 2. That is, while the core body 88 chucked by a dedicated jig (which will be described later) is rotated, the electrostatic powder coating machine 102 spray-coats electrostatically charged electrostatic powder coating material having a certain particle size distribution.

Here, the electrostatic powder coating machine 102 used in the electrostatic powder coating process will be described with reference to FIGS. 4 and 5. The electrostatic powder coating machine 102 shown in the figure has a coating machine body 104.
And an injection unit 106. The applicator main body 104 includes a plurality of linear charging tubes 108 juxtaposed with each other, and a stirring chamber 110 in which the starting ends of the charging tubes 108 communicate with each other.
A merging chamber 112 is provided in which the ends of the charging tubes 108 communicate with each other. Paint particles are supplied into the stirring chamber 110 from a paint supply port 114 formed in communication with the stirring chamber 110, and at the same time, accelerated air is supplied from an air port 116 to the stirring chamber 110.
By being supplied into the stirring chamber 110, the coating particles are rotated and stirred by the accelerating air in the stirring chamber 110 to become uniform, and are branched from the stirring chamber 110 and sent into each charging tube 108. The paint particles dispersed and sent in each of the charge tubes 108 collide with and contact with the inner wall of the charge tubes 108 as they move in the charge tubes 108, repeating friction to be charged and charged. The paint particles charged in each of the charge tubes 108 once merge in the merge chamber 112 to be uniformized, and the discharge port 11
8 is sent to the injection section 106 of the next stage.

The injection unit 106 has a large number of injection tubes 120 branched and connected to the ejection port 118, and the injection nozzle 122 at the tip of each injection tube 120 has a holder 12.
According to the shape and the size of the object to be coated, they are arranged and held in a line, for example. The charged paint particles sent to the ejection unit 106 are branched and guided into each ejection tube 120, and ejected from the respective ejection nozzles 122 toward the core body 88 which is the object to be coated. Note that, in FIG. 4, the core main body 88 is shown larger than the applicator 102 for the sake of convenience, but in reality, the core main body 88 is very small relative to the applicator 102, and the core main body 88 has a core coating described later. It is held by a jig.

The powder coating material used in the coating machine 102 is mainly composed of an epoxy resin and an acid anhydride type curing agent, and
It is a resin powder containing a positively charged body in the composition and has a particle size distribution as shown by the solid line in FIG. This particle size distribution shows the distribution (ratio) of the size of the powder in 100 g of the powder. That is, the powder coating has 5% or less of powder having a particle size of 20 μm or less and 5% or less of powder having a particle size of 100 μm or more, and the maximum peak of the particle size distribution is about 60 μm (55 to 65 μm). The powder having a particle size of about 60 μm accounts for 40% or more. That is, 90% of the entire powder having a particle size of 20 to 100 μm
%, And most of them have a particle size of about 60 μm.

A core coating jig for holding the core body 88 in the electrostatic powder coating process will be described with reference to FIGS. The illustrated coating jig is composed of a first tool 132 that supports the one end surface side of the core body 88 and a second tool 134 that supports the other end surface side of the core body 88. The first tool 132 has a cylindrical tool body 136.
The tool body 136 is mounted on one support portion (not shown) of the holding device. Further, the second tool 134 includes a cylindrical tool body 138, and the tool body 138 is attached to the other holding portion (not shown) of the holding device. A pair of supporting parts of the holding device are arranged to face each other, and these supporting parts have a first tool 132 and a second tool 134.
7, a plurality of cores 8 are arranged between the corresponding first tool 132 and second tool 134, as shown in FIG.
8 is clamped. When coating with the coating machine 102, the first
And, the second tools 132 and 134 are rotated in a predetermined direction, and accordingly, the core body 88 is also rotated, so that the surface of the core body 88 can be uniformly coated.

Referring to FIGS. 7 and 8, the first tool 13
The second tool main body 136 will be described. The tool main body 136 is formed of a hollow cylindrical member, and the tip portion thereof has a taper outer diameter that is sharply reduced toward the tip. The tip taper portion 140 of the tool body 136 functions as an adhesion preventing portion that prevents the paint from adhering, and an annular support portion 142 that projects in the axial direction is integrally provided on the end surface thereof. The outer diameter of the support portion 142 is the core body 8
8 is slightly smaller than the diameter of the mounting hole 90,
Is inserted into the attachment hole 90, the first tool 132 supports one end of the core body 88.

The tool main body 138 of the second tool 134 will be described with reference to FIGS. 7, 9 and 10. The tool main body 138 is formed of a hollow cylindrical member, and the tip end portion thereof is outwardly directed toward the tip end. The diameter is tapered.
The tip taper portion 144 of the second tool 134 is the first tool 1
32 extends in the axial direction longer than the tip tapered portion 140 of 32,
The outer diameter of the tip is smaller than the diameter of the mounting hole 90 of the core body 88. Three notches 146 are formed in the tool body 138 at intervals in the circumferential direction, and each notch 146 is formed.
Extends axially from the tip of the tool body 138 beyond the tip tapered portion 144 and functions as an opening that connects the outside of the core body 88 and the inside of the mounting hole 90 of the core body 88. The number and shape of the cutouts 146 can be set arbitrarily. The tip taper portion 140 of the tool body 136 is inserted into the other end of the mounting hole 90, and the tip taper portion 1 of the second tool 134 is inserted by the insertion.
44 contacts the opening edge of the mounting hole 90 of the core body 88, thereby supporting the other end of the core body 88.

When the core main body 88 held between the first and second tools 132 and 134 is coated by the above-mentioned coating machine 102, the annular support portion 14 of the first tool 132 is coated.
2 covers one end of the mounting hole 90 of the core body 88, and the tip end of the taper tip 140 of the core body 8
8 so as to cover the inner peripheral portion of the one end surface (tapered portion 14
Since the inclination angle of 0 is large, the coating material is prevented from wrapping around the inner peripheral portion of the core body 88), so that the coating material is prevented from adhering to the inner peripheral portion of the one end surface and one end portion of the mounting hole 90. In the second tool 134, since the notch 146 is formed in the tool body 138, the paint from the applicator 102 flows into the mounting hole 90 through the notch 146, and the inner peripheral surface of the mounting hole 90 is coated. Is done.

As described above, the first and second
By holding the core body 88 with the tools 132 and 134 of the core body 88 of the core body 88, the portion (the inner peripheral portion of the one end surface and the one end portion of the mounting hole 90) substantially masked by the first tool 132 is removed. The entire surface can be coated, and the motor core 82 having the insulating coating film 92 as shown in FIG. 2 can be formed.

The jig shown in FIG. 11 may be used as the core coating jig. In FIG. 11, in this modification, the first tool 162 is the cylindrical tool body 1
At the tip of the tool body 164, a tip taper portion 166 having an outer diameter decreasing toward the tip is provided. An annular end surface portion 168 with which the inner peripheral portion of one end surface of the core body 88 abuts is provided on the distal end surface of the distal end taper portion 166, and a circular projecting support portion 170 that projects in the axial direction is provided inside the annular end surface portion 168. This protruding support 1
70 is inserted into the mounting hole 90 of the core body 88. Even when the first tool 162 is used, the inner peripheral portion of the one end surface of the core body 88 is covered with the annular end surface portion 168 that constitutes the adhesion preventing portion, and one end portion of the mounting hole 90 of the core body 88 projects. Since it is covered by the supporting portion 170, no paint is applied to these portions. In this modification, since the annular end surface portion 168 completely covers the inner peripheral surface of the one end surface of the core body 88, it can be reliably unpainted.

The second tool 172 has a hollow cylindrical tool body 174, and the tip of the tool body 174 has:
Tip taper part 17 whose outer diameter decreases toward the tip
6 is provided. The tool body 174 is further provided with three notches 178 (which function as openings) at intervals in the circumferential direction, and each notch 178 extends from the tip of the tool body 174 to the tip tapered portion 176. Furthermore, it extends in the axial direction. Notch 17 in Tip Tapered Part 176
In the region between 8, the width in the circumferential direction is narrowed toward the tip, and the protruding tip is brought into contact with the other end surface of the core body 88.
This causes the other end of the core body 88 to move to the second tool 172.
Held in. Even when this second tool 172 is used, the paint from the applicator 102 flows into the mounting hole 90 of the core body 88 through the notch 178, so that the mounting hole 90
The inner surface of can be painted.

Since it is as described above, even if the first and second tools 162 and 172 of FIG. 11 are used, the same operational effect as described above can be achieved. The second tool 1 shown in FIG.
32 and the second tool 172 of FIG. 11 may be used in combination, and the second tool 134 of FIG. 7 and the first tool 162 of FIG. 11 may be used in combination.

Returning to FIG. 3 again, the process after the electrostatic powder coating process will be described. In the powder removing process of step 3, the motor core 82 subjected to electrostatic powder coating has the magnetic pole forming surface ( The powder adhering to the outer peripheral surface facing the rotor magnet 78), that is, the outer peripheral surface excluding both end surfaces in the axial direction, is removed. As an example, while the coated motor core 82 is being rotated, a spring steel plate is brought into contact with the outer peripheral portion of the motor core 82 to the extent that this rotation does not stop, and the powder is scraped off and removed.

Thereafter, the motor core 82 shifts to the high frequency primary heating step of step 4. In this high-frequency primary heating step, the coated motor core 82 is rotated and passed between the skid coils of the high-frequency heating machine, and the temperature is raised from room temperature to 150 ° C.
Is heated for 20-40 seconds. By this heating, the paint particles on the surface of the motor core 82 are melted, and the next step 5
By cooling the motor core 82 to a temperature not higher than the melting point of the powder coating material in the cooling step, a coating layer is formed on the surface of the motor core 82. After this cooling, compressed air is jetted to the periphery of the motor core 82, and the excess powder coating adhered to these is removed.

Further, the motor core 82 is transferred to the high frequency secondary heating process of step 6 and the motor core 82 is painted.
While being rotated, it is passed between the skid coils of a high-frequency heater and reheated to 200 to 230 ° C. with a temperature rising time of 20 to 40 seconds based on the temperature after the pretreatment process. The motor core 82 that has passed between the skid coils is forcibly cooled to room temperature by compressed air injection or a blower in the cooling step of step 7, and at the same time, excess powder adhering to the jig and the motor core 82 is removed.

In the final step 8, the motor core 8
On the other hand, after-curing is performed to make the coating film uniform, stabilize the state, and increase the film hardness. That is, the motor core 82 is first heated to nearly 240 degrees in 1 minute, kept in this state for 3 minutes, and then cooled to room temperature in 7 minutes. As a result, a good quality coating film can be obtained.

From the powder removing process of step 3 to the after-curing process of step 8, the core body 88,
Therefore, the motor core 82 is connected to the first and second tools 13
Predetermined processing is performed in a state of being held at 2,134.

[0038]

According to the motor core of claim 1 of the present invention, the core main body is exposed at the inner peripheral portion of the one end surface of the base portion and one end portion of the mounting hole. An electrical ground between the body and the motor side is secured. Also, since this portion is not covered with the insulating coating film, by attaching the portion without the insulating coating film to the motor, the thickness of the core main body The radial length, the thickness of the base plate, etc. can be increased. Furthermore, since the inner surface of one end of the core body and the surface of the core body except one end of the mounting hole are covered with an insulating coating film, when the core body is assembled to the motor, the core body is not exposed to the outside. It also eliminates the rust problem of the core body.

According to the motor of claim 2 of the present invention,
Since the inner peripheral portion of the one end surface of the core body and the one end portion of the mounting hole are directly attached to the base plate, electrical grounding between the core body and the base plate is ensured. Also,
Since this portion is not covered with the insulating coating film, the thickness of the core body, the radial length of the core body, the thickness of the base plate, etc. can be increased by the amount corresponding to the thickness of the insulating coating film. In addition, the size and thickness of the motor can be reduced, and the motor design tolerance is increased. Further, since the surface of the core body other than the inner peripheral surface of the one end portion of the core body and the one end portion of the mounting hole is covered with the insulating coating film, the rust problem of the core body is eliminated.

According to the motor of claim 3 of the present invention,
The insulating coating film has a particle size of 20 μm or less of 5% or less and a particle size of 100
Since a powder having a particle size distribution of 5 μm or more and 5% or less is formed by electrostatic powder coating, a thin insulating coating film can be formed satisfactorily and stably.

According to the core coating jig of claim 4 of the present invention, the first tool has a shape in which the coating is not applied to the inner peripheral portion of the one end surface of the core body and the one end portion of the mounting hole. No paint is applied to these parts of the core body. Further, since the second tool has an opening formed therein and the paint flows through the opening into the mounting hole of the core body,
The insulating coating film can also form a mounting hole for the core body.

Further, according to the core coating jig of claim 5 of the present invention, at the tip of the first tool, there is provided an annular support for supporting one end of the mounting hole of the core body, and one end surface of the core body. Since the adhesion preventing portion that prevents the paint from adhering to the inner peripheral portion is provided, the coating on the inner peripheral portion of the one end surface of the core body and the one end portion of the mounting hole is prevented. Further, since the plurality of openings are provided at the tip portion of the second tool, the inner peripheral surface of the mounting hole is favorably painted by the paint flowing through the openings.

[Brief description of drawings]

FIG. 1 is a sectional view showing a spindle motor for a hard disk drive, which is an embodiment of a motor according to the present invention.

FIG. 2 is an enlarged cross-sectional view showing an enlarged motor core of the spindle motor shown in FIG.

3 is a flowchart showing each step of a powder coating method when manufacturing the motor core of FIG.

FIG. 4 is a schematic view showing a triboelectric charging electrostatic powder coating machine used in an electrostatic powder coating process.

5 is a cross-sectional view showing the internal structure of the electrostatic powder coating machine of FIG.

FIG. 6 is a particle size distribution chart showing the particle size distribution of powder used in the electrostatic powder coating machine of FIG.

FIG. 7 is a cross-sectional view showing a core coating jig used to hold the core body in an electrostatic powder coating process and the like, and the core body held by the jig.

8 is a perspective view showing a tip end portion of a first tool of the core coating jig of FIG. 7. FIG.

9 is a front view showing a second tool of the jig for core coating of FIG. 7. FIG.

10 is a perspective view showing a tip portion of the second tool shown in FIG. 9. FIG.

FIG. 11 is a cross-sectional view showing another modified embodiment of the core coating jig.

FIG. 12 is an explanatory diagram for explaining a conventional coating method for the core body.

[Explanation of symbols]

2,88 core body 6,90 Mounting hole 52 Base plate 68 hub 80 Stator 82 Motor core 87 base 89 Teeth 92 Insulation coating film 102 electrostatic powder coating machine 132,162 First tool 134,174 Second tool 140, 144, 166, 176 Tapered tip 142, 170 Annular support 146,178 Notches

Continuation of the front page (56) Reference JP-A-6-253522 (JP, A) JP-A-2-211041 (JP, A) JP-A-53-45342 (JP, A) JP-A-4-178148 (JP , A) Actual Kaihei 7-23976 (JP, U) Actual Kaisho 62-129283 (JP, U) Actual Kaihei 5-33653 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB) Name) H02K 1/18 H02K 1/04 H02K 15/12

Claims (5)

(57) [Claims] 1. Stacking a plurality of core plates
The motor base plate
A core body having an annular base portion provided with mounting holes for mounting and a tooth portion radially outwardly spaced from the base portion in the circumferential direction , and the front of the core body.
The inner peripheral portion of one end surface of the base portion and one end portion of the mounting hole are
On the annular shoulder provided on the mounting part of the motor base plate
In the motor core directly mounted, the inner peripheral portion of the one end surface of the base portion and one end portion of the mounting hole are
The core plate is exposed to the outside, and the surface of the core body excluding the inner peripheral portion of one end surface of the base portion and one end portion of the mounting hole
Whole is characterized by being covered by the insulation coating film motor core. 2. A base plate, a rotor rotatable relative to the base plate, a rotor magnet mounted on the rotor, and a stator mounted on the base plate so as to face the rotor magnet. In a motor composed of a motor core and a coil wound around the motor core, the motor core is formed by stacking a plurality of core plates.
And the base plate
A core body having an annular base portion provided with mounting holes for mounting and a tooth portion radially outwardly spaced from the base portion in the circumferential direction, and the front of the core body.
The inner peripheral portion of the one end surface of the base portion and one end portion of the mounting hole are
Directly mounted on the annular shoulder provided on the base plate mounting part.
The motor is characterized in that the entire surface of the core body except the inner peripheral portion of one end surface of the base portion and the one end portion of the mounting hole is covered with an insulating coating film. 3. The insulating coating film is formed by electrostatic powder coating of powder having a particle size distribution in which a particle size of 20 μm or less is 5% or less and a particle size of 100 μm or more is 5% or less. Item 2. A motor according to item 2. 4. A core body having a mounting hole at the base is coated with paint.
When painting Te, holding function for supporting the core body
And one end of the core body and one end of the mounting hole
Anti-adhesion function to prevent the above paint from adhering to the
When, a core coating jig having, interposed a first tool for supporting one end portion of the core body, it supports the other end portion of the core body and the core body with the first tool
And a second tool held by the first tool,
The antiadhesive machine coating at one end portion of the end surface inner circumferential portion and the mounting hole of the core body is configured in a shape that is not coated
And the second tool is provided with an opening communicating with the attachment hole so that the paint can flow into the attachment hole of the held core body. A jig for painting. Wherein the distal end of said first tool includes an annular supporting portion to which the core is inserted into the mounting hole of the body for supporting one end portion of the mounting hole, one end face in the periphery of the core body An anti-adhesion part is provided to prevent the paint from adhering, and the annular support part and the anti-adhesion part constitute the anti-adhesion function.
The inner peripheral portion of one end surface of the core body and the one end portion of the mounting hole are prevented from being coated, and the second tool is formed into a hollow cylindrical shape.
Plural spaced said openings in the circumferential direction at its distal end as well as, the core coating of claim 4, wherein the inner peripheral surface of the mounting hole by paint flowing through these openings, characterized in that it is coated Jig.