JP4043809B2 - motor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a motor provided with a magnetic attraction member that urges a rotor portion to be attracted to a stator portion side by magnetically attracting the rotor magnet.
[0002]
[Prior art]
In a generally used motor (spindle motor), for example, as shown in FIG. 10, coil windings 2 are provided for a plurality of salient pole portions provided on the stator core 1 constituting the stator portion S. The rotor portion R is wound around the stator portion S via the bearing portion 3 so as to be rotatable, and the rotor magnet 4 provided on the rotor portion R is connected to the stator core 1. Oppositely arranged so that it may adjoin to the outer peripheral side end surface of a salient pole part.
[0003]
In such a motor, a magnetic attraction plate 5 made of a sheet-like magnetic member is provided on the frame 6 on the stator S side so as to face the axial end surface (lower end surface in the drawing) of the rotor magnet 4 in the axial direction. Conventionally, it is attached by an adhesive or the like, and is configured to be urged so as to attract the rotor portion R to the stator portion S side by a magnetic action between the magnetic attraction plate 5 and the rotor magnet 4. Are known. If such an axial attractive force by the sheet-like magnetic attraction plate 5 is used as an axial preload for the thrust bearing or the pivot bearing, the rotor portion R can be maintained in a stable rotational state.
[0004]
[Problems to be solved by the invention]
However, in the motor having such a sheet-like magnetic attraction plate 5, the magnetic attraction member 5 is arranged so as to overlap in the axial direction with respect to the rotor magnet 4. The axial thickness (height) of the motor is an increasing factor, and there is a fear that it is against the recent demand for miniaturization. In order to reduce the thickness (height) in the axial direction, it is conceivable to form the magnetic attraction plate thin. However, if this is done, magnetic saturation tends to occur and a sufficient magnetic attraction force cannot be obtained. In addition, it is conceivable to reduce the distance between the rotor magnet and the magnetic gap, but the influence of variations in assembly accuracy and component accuracy increases, and stable magnetic attractive force cannot be obtained. As a result, since high precision is required, the manufacturing cost is inevitably increased. Such a decrease in productivity becomes a very important problem especially in a motor that is small and has to use expensive materials in order to obtain high characteristics.
[0005]
SUMMARY OF THE INVENTION An object of the present invention is to provide a motor that can sufficiently obtain a magnetic attractive force by a magnetic attractive member with a simple and small configuration.
[0006]
[Means for Solving the Problems]
In order to solve the above problems, in the motor according to claim 1, the magnetic attraction member is Annular rotor magnet And the surrounding wall Pair only in radial direction A substantially cylindrical shape arranged concentrically with the rotor magnet Standing wall have. That is, the inventors of the present application have conducted various investigations and studies on the magnetic attractive force obtained by the magnetic attractive member. As a result, if there is a member facing the rotor magnet in the radial direction, It has been found that members facing in the axial direction have little influence on the magnetic attractive force. That is, by adopting the motor having the configuration according to claim 1 as described above, the magnetic flux from the rotor magnet effectively acts as a magnetic attraction force by the magnetic attraction member, and the thrust position of the rotating body is restricted. To the posture regardless of It was found to be well maintained.
[0007]
In the motor according to claim 2, the magnetic attraction member according to claim 1 is provided. Axial end of From A substantially annular mounting portion extending in a direction away from the rotor magnet in the radial direction is formed. For this reason, the attachment / arrangement of the magnetic attraction member can be easily and reliably performed without being obstructed by the rotor magnet via the attachment portion.
[0008]
Further, in the motor according to claim 3, the mounting portion in claim 2 is arranged in a core slot between a plurality of salient poles extending radially in the stator core and wound with the coil winding. Therefore, the radial length of the mounting portion can be increased in a state where the stator core side and the mounting portion are wrapped in the axial direction, and the motor can be reduced in size while being reduced in size. The attachment rigidity of the suction member is improved.
[0009]
Furthermore, in the motor according to claim 4, in the above claim 2. The outer peripheral surface of the substantially annular convex portion whose inner end portion is formed on the rotor portion side of the fixed frame to which the stator core and the coil winding are attached Since the magnetic attraction member is positioned by being in contact with the magnetic attraction member, the magnetic attraction member can be attached with high precision by a simple bending forming structure, and stable motor characteristics can be obtained at low cost. It is supposed to be.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings while explaining an outline of a hard disk drive (HDD) using a hydrodynamic bearing device as an example of a motor to which the present invention is applied.
[0013]
As the shaft rotation type HDD motor shown in FIG. 1, a motor adopting a hydrodynamic bearing device is adopted, but the whole is composed of a stator portion 10 as a fixed member and the stator portion 10. And a rotor portion 20 as a rotating member assembled from above. Among them, the stator unit 10 has a fixed frame 11 that is screwed to the fixed base side (not shown). The fixed frame 11 is made of an aluminum-based metal material in order to reduce the weight, but the inner peripheral wall surface of the annular bearing holder 12 formed so as to stand upright at the substantially central portion of the fixed frame 11. On the side, a bearing sleeve 13 as a fixed bearing member formed in a hollow cylindrical shape is joined to the bearing holder 12 by press-fitting or shrink fitting. The bearing sleeve 13 is made of a copper-based material such as phosphor bronze in order to facilitate drilling of a small diameter.
[0014]
A stator core 14 made of a laminate of electromagnetic steel sheets is fitted on the outer peripheral side mounting surface of the bearing holder 12 and is provided so as to protrude radially outward in the stator core 14. Coil windings 15 are wound around the plurality of salient pole portions.
[0015]
Further, a rotating shaft 21 constituting the rotor portion 20 described above is rotatably inserted into a center hole provided in the bearing sleeve 13. That is, the dynamic pressure surface formed on the inner peripheral wall portion of the bearing sleeve 13 is arranged so as to face the dynamic pressure surface formed on the outer peripheral wall surface of the rotating shaft 21 in the radial direction, and the minute gap portion thereof A radial dynamic pressure bearing portion RB is formed. More specifically, the dynamic pressure surface on the bearing sleeve 13 side and the dynamic pressure surface on the rotating shaft 21 side in the radial dynamic pressure bearing portion RB are opposed to each other in a circumferential manner through a minute gap of several μm. Lubricating fluid such as lubricating oil, magnetic fluid, air, or the like is injected or interposed in the bearing space consisting of minute gaps so as to continue in the axial direction.
[0016]
Further, on at least one side of both the dynamic pressure surfaces of the bearing sleeve 13 and the rotary shaft 21, a radial dynamic pressure generating groove having a herringbone shape or the like is divided into two blocks in the axial direction and is annularly recessed. During rotation, the lubricating fluid (not shown) is pressurized by the pumping action of the radial dynamic pressure generating groove to generate dynamic pressure, which will be described later together with the rotating shaft 21 by the dynamic pressure of the lubricating fluid. The rotary hub 22 is configured to be axially supported in a non-contact state in the radial direction with respect to the bearing sleeve 13.
[0017]
Further, the rotating hub 22 that constitutes the rotor portion 20 together with the rotating shaft 21 is made of a substantially cup-shaped member made of ferritic stainless steel, and the joining hole 22a provided in the central portion of the rotating hub 22 has the above-described structure. The rotary shaft 21 is integrally joined to the illustrated upper end portion by press fitting or shrink fitting. The rotating hub 22 has a substantially cylindrical barrel portion 22b on which a recording medium disk such as a magnetic disk (not shown) is mounted on the outer peripheral portion, and projects from the barrel portion 22b radially outward. The recording medium disk 22c is provided with a disk mounting portion 22c for supporting the medium disk in the axial direction, and the recording medium disk is pressed by a pressing force from the upper side of a clamper (not shown) screwed so as to be covered from the upper side. It is supposed to be fixed.
[0018]
An annular rotor magnet 22d is attached to the lower inner wall surface side of the body portion 22b of the rotating hub 22. The rotor magnet 22d is disposed close to the outer peripheral side end surface of each salient pole portion of the stator core 14 described above in an annular manner.
[0019]
Further, a magnetic attraction member 17 formed by press-molding a magnetic member such as an iron-based material into a substantially cylindrical shape at a position directly below the lower end surface of the rotor magnet 22d in the drawing, that is, the end surface facing the fixed frame 11 side. Is mounted on the surface of the fixed frame 11. The magnetic attraction member 17 is composed of a substantially cylindrical member as shown in FIG. 2D, for example, and an upright wall portion erected in a flange shape at the outermost circumferential position of the substantially cylindrical shape. 17a is arrange | positioned so that it may adjoin and oppose the radial direction with respect to the inner peripheral side wall surface of the rotor magnet 22d mentioned above. That is, the standing wall portion 17a is formed to the upper side from the lower end surface of the rotor magnet 22d.
[0020]
In the magnetic attraction member 17, the outer peripheral surface on the lower end side of the upright wall portion 17 a provided in a flange shape abuts against the upright wall surface of the stepped portion 11 a provided in the fixed frame 11 from the inner diameter side. The entire magnetic attraction member 17 is positioned with high accuracy in the radial direction by the position regulating action of the step portion 11a.
[0021]
In addition, a flat plate-like mounting portion 17b is integrally connected to the lower end portion of the standing wall portion 17a through a bent portion that is bent at a substantially right angle. The mounting portion 17b extends from the lower end portion of the standing wall portion 17a toward the inner diameter side, that is, toward the inner diameter side from the rotor magnet 22d, and the lower surface of the mounting portion 17b illustrated in FIG. 11 is fixed to the upper surface of the figure by a fixing means such as adhesion.
[0022]
Here, as described above, the magnetic attraction member 17 in the present embodiment is formed from a press-molded product of a magnetic member, but is manufactured as shown in FIG. 2, for example. First, a flat plate material 17 ′ as shown in FIG. 2 (a) is prepared, and the flat plate material 17 ′ is drawn from above in the drawing, for example, FIG. Molded into a cup shape as shown in (b). Next, press punching is performed at a position corresponding to the bottom portion of the cup shape so as to penetrate a hole 17'a having a desired size as shown in FIG. Finally, the outer peripheral portion of the material 17 ′ is annularly cut into a predetermined size to obtain the final substantially cylindrical magnetic attraction member 17 shown in FIG. .
[0023]
Note that the reference numeral “17c” in FIG. 2D represents a burr formed at the time of the final cutting of the outer periphery, and such a burr 17c can be manufactured so as to be completely removed. is there. It is also effective to construct the burr 17c so as to remain positively as a facing protrusion against the magnet so that the magnetic flux is easily concentrated on the magnet facing protrusion 17c.
[0024]
Returning to FIG. 1 again, a disc-shaped thrust plate 23 is fixed to the tip portion of the rotary shaft 21 on the lower end side in the figure by shrink fitting or press fitting. The thrust plate 23 is disposed so as to be accommodated in a cylindrical recess 13a that is recessed in the center portion on the lower end side of the bearing sleeve 13 shown in the figure. , The dynamic pressure surface provided on the upper side surface of the thrust plate 23 is disposed opposite to the dynamic pressure surface provided in the hollow portion 13a of the bearing sleeve 13 so as to be close to the axial direction. A thrust dynamic pressure generating groove having a herringbone shape (not shown) is formed on the upper dynamic pressure surface of the thrust plate 23, and both dynamic pressure surfaces of the thrust plate 23 and the bearing sleeve 13 are formed between the thrust dynamic pressure surfaces. A thrust dynamic pressure bearing portion SBa on the upper side is formed in the facing gap portion.
[0025]
Furthermore, a counter plate 18 made of a disk member having a relatively large diameter is disposed so as to be close to the lower dynamic pressure surface of the thrust plate 23 in the figure. The counter plate 18 is disposed so as to close the lower end side opening of the bearing sleeve 13, and the outer peripheral side portion of the counter plate 18 is fixed to the bearing sleeve 13 side by caulking or the like. A thrust dynamic pressure generating groove having a herringbone shape (not shown) is formed on the lower dynamic pressure surface of the thrust plate 23, thereby forming a lower thrust dynamic pressure bearing portion SBb. ing.
[0026]
In this way, both the dynamic pressure surfaces on the thrust plate 23 side constituting a pair of thrust dynamic pressure bearing portions SBa, SBb arranged adjacent to each other in the axial direction, and the bearing sleeve 13 and the counter plate 18 that are adjacent to each other. Both dynamic pressure surfaces on the side are opposed to each other in the axial direction through a small gap of several μm, and lubricating fluid such as oil, magnetic fluid, and air is contained in the bearing space formed by the minute gap. Lubricating fluid is injected or interposed so as to be continuous in the axial direction through the outer peripheral side passage of the thrust plate 23, and lubrication fluid is added by the pumping action of the thrust dynamic pressure generating groove provided in the thrust plate 23 during rotation. In the non-contact state in which the rotary shaft 21 and the rotary hub 22 float in the thrust direction due to the dynamic pressure of the lubricating fluid. And it is configured to be supported.
[0027]
And according to the motor concerning this embodiment provided with magnetic attraction member 17 as mentioned above, magnetic flux from rotor magnet 22d is effectively acted as magnetic attraction by magnetic attraction member 17, and the thrust position of a rotating body is set. Regulations are maintained well regardless of the posture of the rotating body.
That is, as a result of investigating and examining the magnetic attraction force obtained by the magnetic attraction member 17 in various ways, a member facing the rotor magnet 22d in the radial direction, that is, the above-described standing wall portion 17a of the magnetic attraction member 17 is present. Thus, it has been found that a sufficient magnetic attractive force can be obtained, and the conventional member that faces the rotor magnet 22d in the axial direction has little influence on the magnetic attractive force.
[0028]
For example, as shown in the reference example in FIG. 3, the magnetic attraction member 17 ″ disposed close to the rotor magnet RM is made to have a radial facing portion 17 ″ a and an axial facing portion 17 ″ with respect to the rotor magnet RM. b, and the radial facing portion 17 ″ a of the magnetic attraction member 17 ″ is maintained in an unmoved state, and only the axial facing portion 17 ″ b is shown in FIG. The distance from the rotor magnet RM is changed by sequentially moving in the axial direction as shown in FIG. Then, as shown in FIG. 4, the axial magnetic force generated by the entire magnetic attraction member 17 ″ with respect to the change in the distance (horizontal axis) between the rotor magnet RM and the axially facing portion 17 ″ b. It was found that the attractive suction force (vertical axis) hardly changed.
From this, it can be understood that the necessary magnetic attraction action can be effectively obtained by using the magnetic attraction members 17 facing in the radial direction in the present embodiment described above.
[0029]
In the motor according to the present embodiment, the mounting portion 17b provided on the magnetic attraction member 17 is provided so as to extend in a flat plate shape toward the inner diameter direction away from the rotor magnet 22d. The suction member 17 can be easily and reliably attached without being obstructed by the rotor magnet 22d. Further, since the mounting portion 17b is integrally connected to the standing wall portion 17a via a bent portion, the mounting portion 17b can be efficiently manufactured by a simple bending configuration such as press molding. It has become.
[0030]
In addition, since the vertical wall portion 17a of the magnetic attracting member 17 is in contact with the stepped portion 11a on the fixed frame 11 side, the magnetic attracting member 17 is attached with high accuracy. As a result, stable motor characteristics can be obtained.
[0031]
On the other hand, in the embodiment shown in FIG. 5 in which the same components as those in the above-described embodiment are represented by the same reference numerals, an annular protrusion 11b having a convex cross section disposed concentrically on the inner diameter side of the rotor magnet 22d. The magnetic attracting member 37 is provided so as to protrude from the surface of the fixed frame 11 toward the upper side in the figure, and is formed on the outer peripheral side of the annular protrusion 11b in a ring shape having different protruding directions. It is attached so as to be covered by being inserted in the axial direction from above. And the outer peripheral side wall surface of this magnetic attraction member 37 is made into the arrangement | positioning relationship which faces the inner peripheral side wall surface of the rotor magnet 22d in proximity to the radial direction. Also in such an embodiment, the same operation and effect as the above-described embodiment can be obtained.
[0032]
Similarly, in the embodiment shown in FIG. 6 and FIG. 7 in which the same components as those of the above-described embodiments are represented by the same reference numerals, the inner peripheral side wall surface of the rotor magnet 22d is opposed to the radial direction. A mounting portion 47b extending to the inner diameter side is provided at the lower end of the flange-like standing wall portion 47a of the provided magnetic attraction member 47. In particular, in this embodiment, the inner peripheral edge of the mounting portion 47b is provided. In addition, a plurality of inward projecting portions 47b1 are provided so as to project in the radial direction toward the center side so as to form substantially equal pitch intervals in the circumferential direction.
[0033]
Each of the inward projecting portions 47b1 is disposed so as to extend into the core slot between the salient pole portions provided on the stator core 14 and wound with the coil winding 15, respectively. Therefore, each inward protruding portion 47b1 of the mounting portion 47b extends toward a space defined between the coil windings 15. And in this embodiment, each inward protrusion part 47b1 of the said attaching part 47b and the coil winding 15 are arrange | positioned so that it may be in the position wrapped in the axial direction.
[0034]
According to such an embodiment, in addition to the functions and effects of the above-described embodiments, each inward protruding portion 47b1 of the attachment portion 47b of the magnetic attraction member 47 is wrapped with the coil winding 15 in the axial direction. Therefore, the entire motor can be made thinner in the axial direction, and the radial length of the mounting portion 47b can be increased. The mounting rigidity of the magnetic attraction member 47 is improved while increasing.
[0035]
On the other hand, in the embodiment shown in FIG. 8, the annular protrusions 11c arranged concentrically on the inner diameter side of the rotor magnet 22d are formed from the surface of the fixed frame 11 in the same manner as the embodiment shown in FIG. The magnetic attraction member 57 formed in a substantially cylindrical shape is attached to the outer peripheral side of the annular protrusion 11c so as to be inserted from the upper side in the figure. Yes. And the outer peripheral side wall surface of the said magnetic attraction member 57 is arrange | positioned so that the radial direction may adjoin and oppose with respect to the inner peripheral side wall surface of the rotor magnet 22d.
[0036]
At this time, the end surface on the protruding side (the upper end side in the figure) of the annular protrusion 11c described above is formed as a support surface of the stator core 14, and the stator core 14 is received in the axial direction on the support surface of the annular protrusion 11c. It is set in a state and fixed with an adhesive or the like.
[0037]
In such an embodiment, in addition to the functions and effects of the above-described embodiments, the stator core 14 is held with high accuracy and strength. In particular, the holding height of the stator core 14 can be stably obtained. As a result, the magnetic attractive force between the rotor magnet 22d and the rotor magnet 22d is stabilized.
[0038]
Furthermore, in the embodiment shown in FIG. 9, the coil winding 15 is wound around the attachment portion 67 b extending radially inward from the magnetic attraction member 67 facing the rotor magnet 22 d in the radial direction. Together with the stator core 14 (core winding set), an integral core molded product MC is formed by a molding resin MR such as a liquid crystal polymer. The core molded product MC is manufactured using, for example, insert molding, and the core molded product MC after the insert molding is joined to the fixed frame 11 side.
[0039]
According to such an embodiment, in addition to the operations and effects according to each of the above-described embodiments, the core winding set including the stator core 14 and the magnetic attraction member 67 have the same degree of coaxiality in the molding die. Positioning is performed with high accuracy in the height direction, and as a result, good motor characteristics can be obtained.
[0040]
As mentioned above, the invention made by the present inventor has been specifically described on the basis of the embodiment. However, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the scope of the invention. Needless to say.
[0041]
For example, each of the embodiments described above applies the present invention to an HDD motor, but the present invention is also applicable to a motor used in various other devices or a motor that does not include a dynamic pressure bearing portion. The present invention can be similarly applied.
[0042]
【The invention's effect】
As described above, in the motor according to claim 1, the magnetic attraction member having a substantially cylindrical member is disposed concentrically with the rotor magnet so as to face the peripheral wall surface of the rotor magnet in the radial direction. Since magnetic flux from the rotor magnet is effectively applied as magnetic attraction force, the magnetic attraction force by the magnetic attraction member can be obtained sufficiently with a simple and small configuration, and it is good while miniaturizing the motor Motor characteristics can be maintained.
[0043]
According to a second aspect of the present invention, there is provided a motor connected to the stator portion of the magnetic attraction member according to the first aspect of the present invention so as to extend in a flat plate shape in a direction away from the rotor magnet in the radial direction. Since the magnetic attracting member is easily and reliably attached and arranged via the attaching portion, productivity can be improved while obtaining the above-described effects more reliably.
[0044]
Furthermore, the motor according to claim 3 is arranged such that the mounting portion according to claim 2 extends in a core slot between the plurality of salient poles provided in the stator core, Since the mounting portion is wrapped in the axial direction to increase the radial length of the mounting portion, the mounting rigidity of the magnetic attraction member is improved while reducing the size of the motor. The effect can be further ensured.
[0045]
Furthermore, the motor according to claim 4 is provided with a bent portion that integrally connects the magnetic attraction member according to claim 2 and the mounting portion with respect to the stator portion, and the bent portion is provided on the step portion on the stator portion side. Since the magnetic attraction member is positioned by contacting the magnetic attraction member, the magnetic attraction member can be attached with high accuracy by a simple bending molding configuration, and stable motor characteristics can be obtained at low cost. The effects described above can be obtained more inexpensively and reliably.
[0046]
On the other hand, the motor according to claim 5 is configured such that the magnetic attraction member in claim 2 is configured so as to form an integral core molded product together with the stator portion by molding resin. Since it is performed with accuracy, productivity can be enhanced in addition to the above-described effects.
[0047]
According to a sixth aspect of the present invention, the magnetic attraction member according to the first aspect is provided with an axially opposed portion that is opposed to the axial end surface of the rotor magnet in the axial direction to further magnetize the magnetic flux from the rotor magnet. Since it is configured to effectively act as a suction force, the above-described effects can be further improved.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional explanatory view showing an outline of a shaft rotation type HDD motor according to an embodiment of the present invention.
2 is a longitudinal cross-sectional explanatory view showing a manufacturing process of a magnetic attraction member used in the HDD motor shown in FIG. 1; FIG.
FIG. 3 is a partial vertical cross-sectional explanatory view showing a state in which a magnetic attraction member having a reference structure is separated from a rotor magnet in an axial direction.
4 is a diagram showing a change in magnetic attractive force when the magnetic attractive member is moved away from the rotor magnet in the axial direction in correspondence with FIG. 3; FIG.
FIG. 5 is an explanatory longitudinal sectional view showing an outline of an HDD motor according to another embodiment of the present invention.
FIG. 6 is an explanatory longitudinal sectional view showing an outline of an HDD motor in still another embodiment of the present invention.
7 is a schematic plan explanatory view showing a stator portion of the HDD motor shown in FIG. 6. FIG.
FIG. 8 is a longitudinal sectional explanatory view showing an outline of a HDD motor in still another embodiment of the present invention.
FIG. 9 is a longitudinal sectional explanatory view showing an outline of a HDD motor in still another embodiment of the present invention.
FIG. 10 is a semi-longitudinal cross-sectional explanatory diagram showing an outline of a commonly used shaft rotation type HDD motor.
[Explanation of symbols]
10 Stator section
11 Fixed frame
13 Bearing sleeve
14 Stator core
15 Coil winding
20 Rotor part
21 Rotating shaft
RB radial dynamic pressure bearing
22 Rotating hub
22d Rotor magnet
17, 37, 47, 57, 67 Magnetic attraction member
17a, 37a, 47a, 57a, 67a Standing wall
17b, 37b, 47b, 57b, 67b Mounting part
SBa, SBb Thrust dynamic pressure bearing
57b Radial facing part

Claims (5)

A stator portion having an annular stator core and a plurality of salient pole portions projecting in a radial direction from the stator core, and a stator portion having a coil winding wound around each of the salient pole portions ;
A rotor portion that is rotatably supported by the stator portion via a bearing portion and includes an annular rotor magnet that faces the salient pole portion in a radial direction ;
An upright wall portion extending in a substantially cylindrical shape in the axial direction and concentrically arranged with the rotor magnet and facing the rotor magnet in the radial direction;
A motor having the standing wall portion, and a magnetic attraction member facing only the rotor magnet only in the standing wall portion . 2. The motor according to claim 1 , wherein a substantially annular mounting portion extending in a radial direction away from the rotor magnet is formed at an axial end portion of the magnetic attraction member. The motor according to claim 2, wherein the attachment portion is disposed between the salient pole portions in the axial direction . The magnetic attraction member is configured such that an inner end portion of the attachment portion is in contact with an outer peripheral surface of a substantially annular convex portion formed on the rotor portion side of a fixed frame to which the stator core and the coil winding are attached. The motor according to claim 2, wherein the positioning is performed.   The outer end portion of the attachment portion is in contact with the inner peripheral surface of a substantially annular convex portion formed on the rotor portion side of a fixed frame to which the stator core and the coil winding are attached. The motor according to claim 2, wherein the member is positioned.

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