JP2000092799A - Spindle motor and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a spindle motor provided with a constitution in which the end part of a shaft can be fixed surely to a hole for fixation, in a fixation- side member such as a motor bracket or the like in a precisely positioned state, and to provide a method which manufactures the spindle motor. SOLUTION: A shaft 8, which is arranged in the central part in an erected and installed state and which is used as a rotation support shaft, is a cylindrical body whose diameter is smaller than the hole diameter of a hole 9 for fixation in a fixation-side member 4 which is fixed to the shaft 8. It is shaped in such a way that a recessed part 10 for fixation which is recessed in the direction of the axial center from the end face, and a cylindrical part 13 around the recessed part 10 are formed in a fixation-side end part. In a state that the fixation-side end part is inserted into the hole 9 for fixation, the shaft 8 plastically deforms the cylindrical part 13 to a diameter-expanding direction by a force- fitting member 11 when the force-fitting member 11 whose diameter is larger than that of the recessed part 10 for fixation is force-fitted to the recessed part 10 for fixation, and it comes into pressure contact with the circumferential face of the hole 9 for fixation. As a result, the fixation-side end part is fixed to the fixation-side member 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a spindle motor used as a rotary drive source in a recording disk device such as a hard disk (magnetic disk) and a method for manufacturing the same.

[0002]

2. Description of the Related Art As a spindle motor used for this kind of application, a general structure of a fixed shaft type is disclosed in, for example, Japanese Patent Application Laid-Open No. 7-312841. The configuration of this spindle motor will be briefly described. It is as follows.
That is, the shaft is fixed to the central base portion of the fixed-side motor bracket in an upright state in which the shaft protrudes upward. A hard disk is fitted on the outer peripheral surface of the shaft so as to be rotationally driven. A cylindrical rotor hub is rotatably supported via a pair of upper and lower bearings. A stator is fixedly held on the motor bracket in a concentric arrangement with the fixed shaft. A cylindrical rotor yoke is fixed to the lower portion of the outer peripheral end of the rotor hub, and a rotor magnet is mounted on the inner peripheral surface of the rotor yoke so as to face the stator with a small gap. Apart from this, there is also a spindle motor having a configuration in which a shaft to which a rotor hub is fixed is rotatably supported by a motor bracket.

[0003] By the way, in the conventional spindle motor,
When the shaft is fixed to the motor bracket or the rotor hub, a means for press-fitting the end of the shaft into a fixing hole of the motor bracket or the rotor hub and bonding the shaft with an adhesive is generally adopted. For example, when the shaft is fixed to the motor bracket, as shown in FIG. 6A, a fixing hole 1a having a hole diameter slightly smaller than the diameter of the shaft 2 is formed in the center of the motor bracket 1. After the adhesive 3 is applied to the peripheral surface of the fixing hole 1a, the end of the shaft 2 is press-fitted into the fixing hole 1a as shown by an arrow to perform mutual positioning. When the adhesive 3 is cured, the motor bracket 1 and the shaft 2 are fixed to each other as shown in FIG. The shaft 2 is provided with a hole-shaped recess 2a in the end face on the insertion side to impart a slight elasticity in the radial direction, so that the shaft 2 can be smoothly pressed into the fixing hole 1a. ing.

[0004]

However, FIG.
As shown in (b), in addition to the radial residual stress R1 of the motor bracket 1 in the motor bracket 1 near the shaft 2 after the shaft 2 has been press-fitted, the motor bracket 1 is press-fitted. A residual stress R2 is generated in the thickness direction of the shaft 2, that is, in the axial direction of the shaft 2, and the shaft 2 is subjected to a springback phenomenon due to the residual stress R2 in the axial direction.

[0005] Therefore, a force that pushes back the shaft 2 in the direction opposite to the press-fitting direction due to the springback phenomenon acts on the shaft 2, so that the relative position with respect to the motor bracket 1 is apt to vary. It is difficult to accurately position the supported rotor hub at a predetermined height with respect to the reference surface of the motor bracket. Therefore, in the conventional spindle motor, it is difficult to set the hard disk externally fitted to the disk mounting surface of the rotor hub at a fixed height position from the reference surface of the motor bracket. Difficult to set to accuracy. In particular, a spindle motor used as a rotation drive source of a recording medium such as a hard disk requires extremely high rotational accuracy. Therefore, it is a serious problem that the above-described rotational shake cannot be set to a predetermined accuracy. In FIG. 6, the shaft-fixed type spindle motor for fixing the shaft 2 to the motor bracket 1 has been described. However, the shaft-rotation type spindle motor for fixing the shaft by press-fitting the shaft into the fixing hole of the rotor hub is also described above. There is a similar problem.

Further, if a notch or the like for drawing out a coil is formed near a fixing hole in a motor bracket or the like, the motor bracket 1 shown in FIG.
Residual stress R1 in the radial direction and residual stress R2 in the thickness direction
Are concentrated in the direction toward the notch. As a result, there arises a problem that the shaft is tilted and the rotational runout accuracy of the motor is deteriorated.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to fix a fixed end of a shaft to a fixing hole of a fixed member such as a motor bracket in an accurate positioning state. An object of the present invention is to provide a spindle motor having a configuration that can be securely fixed and a method of manufacturing the spindle motor.

[0008]

In order to achieve the above-mentioned object, the present invention is directed to a rotating shaft, which is arranged in a central portion in an upright state, and a stator is arranged concentrically with the shaft. In a spindle motor in which a rotor magnet fixed to a rotor is disposed opposite to the stator at a predetermined gap, the shaft has a diameter smaller than a diameter of a fixing hole of a fixed side member mutually fixed to the shaft. A cylindrical body having a diameter, a fixing recess recessed in the axial direction from the end face at the fixed end and a cylindrical portion surrounding the fixing recess are formed, and the fixed end is formed in the fixing hole. In the inserted state, the cylindrical portion having a diameter larger than that of the fixing recess and having been plastically deformed in the radially expanding direction by a press-fitting member press-fitted into the fixing recess forms a periphery of the fixing hole. Pressing against the surface, the fixed side end It has become fixed configuration to the fixed-side member.

In this spindle motor, the mutual fixing structure of the fixed side member and the shaft is such that the shaft having a diameter smaller than the diameter of the fixing hole is simply inserted without press-fitting into the fixing hole, thereby fixing the press-fitting member. The cylindrical part of the shaft is plastically deformed in the radially expanding direction by press-fitting into the recess, and is pressed against the peripheral surface of the fixing hole. Since no residual stress is generated in the thickness direction by not performing this, the springback phenomenon does not act on the shaft. Therefore, the shaft can be accurately positioned and fixed at a predetermined position with respect to the fixed side member, and a required fixing strength can be obtained by pressing the cylindrical portion of the shaft against the peripheral surface of the fixing hole by plastic deformation. be able to. Thus, for example, when used as a rotation drive source for a hard disk, the mounting position of the hard disk can be accurately positioned and provided at a predetermined height. Therefore, it is necessary to reliably set the rotational runout as a motor to a predetermined accuracy. Can be.

[0010] The term "fixed side member" as used herein refers to a motor bracket on which a shaft is fixed in an upright state in a fixed shaft type spindle motor. A rotor hub that is fixed and rotates with the shaft relative to the motor bracket.

In the above embodiment of the present invention, the press-fitting member has a substantially cylindrical shape, and at least a central portion of the press-fitting member has an extruded portion bulged to an outer diameter larger than the hole diameter of the fixing recess. It has the provided shape. As a result, the press-fitting member having a substantially cylindrical shape has only a partially extruded portion having a diameter larger than the hole diameter of the fixing recess, and has a small frictional resistance at the time of press-fitting. Due to having some elasticity inward, it can be smoothly pressed into the fixing recess. In addition, there is an advantage that the hollow portion of the pressure member can be used as a wiring space for a coil lead wire or the like.

In another embodiment of the present invention, a sphere having a diameter larger than the hole diameter of the fixing recess can be used as the press-fitting member. As a result, since the press-fitting member made of a sphere has a small contact area with the peripheral surface of the fixing recess, the press-fitting member is smoothly pressed into the fixing recess and the cylindrical portion of the shaft is easily plastically deformed in the radially expanding direction. Can be done.

[0013] In the above invention, a notch is formed in the fixed member made of a motor bracket in the vicinity of the fixing hole, and the notch is formed in the shaft on the opening side with respect to the fixing recess. A large-diameter portion having a diameter larger than the fixing recess may be formed, and a step may be formed between the fixing recess and the large-diameter portion. As a result, it is possible to prevent the residual stress in the radial direction of the shaft generated in the fixed member from concentrating in the direction toward the notch by the step portion, thereby preventing the shaft from tilting and maintaining the shaft in the vertical state. Thus, it is possible to prevent deterioration of the rotational runout accuracy of the motor.

The method for manufacturing a spindle motor according to the present invention comprises:
A step of applying an adhesive to the peripheral surface of the fixing hole or the outer peripheral surface of the fixed side end of the shaft, and inserting the fixed side end into the fixing hole to form the shaft and the fixed side member. Curing the adhesive while maintaining the relative position, and press-fitting the press-fitting member into the fixing recess of the shaft to plastically deform the cylindrical portion of the shaft so as to bulge in the radial direction. Press-contacting the peripheral surface of the fixing hole.

In this method of manufacturing a spindle motor, the shaft simply inserted into the fixing hole of the fixed member is accurately positioned at a predetermined position with respect to the fixed member, and the adhesive is cured while maintaining this positioning state. After the shaft and the fixed-side member are temporarily fixed, the cylindrical portion of the shaft is not press-fitted, but instead of the press-fitting member, the fixing hole is formed by plastic deformation that expands in the radially expanding direction due to press-fitting into the fixing recess of the press-fitting member. Since it is brought into pressure contact with the peripheral surface, no residual stress is generated in the fixed-side member in the radial direction of the shaft. Therefore, the shaft is accurately positioned at a predetermined position with respect to the fixed side member by the fact that the spring back phenomenon does not act and the press-fitting member is press-fitted into the fixing recess in a state where it is accurately positioned and temporarily fixed. Can be fixed.

[0016]

Preferred embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a longitudinal sectional view showing a spindle motor according to a first embodiment of the present invention. FIG. 1 illustrates a spindle motor of a fixed shaft type. A thick central base 7 is provided at the center of a motor bracket 4 serving as a base of the spindle motor. Is provided with a fixing hole 9 at the center thereof. The lower end of the shaft 8 is inserted into the fixing hole 9 and fixed in an upright state. The details of the means for fixing the shaft 8 to the motor bracket 4 will be described later, and the fixing structure will be briefly described below.

The shaft 8 is a cylindrical body having a diameter slightly smaller than the diameter of the fixing hole 9, and has a fixing recess 10 formed of a circular hole that is recessed in the axial direction from the lower end surface. . After the lower end of the shaft 8 is simply inserted into the fixing hole 9, the extrusion is formed into a cylindrical shape and bulges to an outer diameter slightly larger than the hole diameter of the fixing recess 10 at the center in the cylinder center direction. By press-fitting the press-fitting member 11 having the portion 12 formed therein into the fixing recess 10, the cylindrical portion 13 of the shaft 8 provided with the fixing recess 10 swells in the radially expanding direction by the pushing portion 12. It is plastically deformed and pressed against the peripheral surface of the fixing hole 9.

The motor bracket 4 is provided with a cylindrical support projecting wall 14 projecting upward in a concentric arrangement on the outer side with respect to the central base 7.
The stator core 18 has a stator coil 19
Is externally fitted and fixed.
A lead wire (not shown) of the stator coil 19 is drawn out of the motor bracket 4 and is electrically connected to a terminal area of a flexible circuit board (not shown).

The rotor hub 20 for integrally rotating and driving a hard disk (not shown) has a substantially cylindrical shape as a whole, and has an inner cylindrical wall portion 21 arranged along the inner peripheral portion thereof. A disk mounting surface 22 for externally fitting and fixing the hard disk is formed on the outer surface of the outer peripheral portion so as to protrude outward. This rotor hub 20
The inner peripheral wall portion 21 is rotatably supported on the outer peripheral surface of the shaft 8 via a pair of upper and lower ball bearings 23 and 24 made of a ferromagnetic material.

The upper ball bearing 23 is an annular holding step 2 formed by cutting off the inner peripheral surface of the base of the rotor hub 20.
When the outer ring 23a is positioned in contact with the outer ring 23a from above, the outer ring 23a is adhered to the inner peripheral surface of the base of the rotor hub 20 with an adhesive, and the inner ring 23b is fixed to the outer peripheral surface of the shaft 8 with an adhesive. On the other hand, the lower ball bearing 24
The outer ring 24a is fixed to the inner peripheral wall 21 with an adhesive in a state where the outer ring 24a is positioned in contact with the annular holding step 28 formed from the inner peripheral surface of the rotor hub 20 by cutting the inner peripheral surface thereof from below. And the inner race 24b is
Is bonded to the outer peripheral surface with an adhesive. The upper end opening of the rotor hub 20 is closed by a cap 29.

A cylindrical rotor yoke 30 is fixed to the lower surface of the disk mounting surface 22 of the rotor hub 20 in a suspended state, and the cylindrical rotor magnet 31 fixed inside the rotor yoke 30 is fixed to the stator core 18. Are arranged facing each other with a predetermined gap in the radial direction.

In this spindle motor, a magnetic action is generated between the stator 17 and the rotor magnet 31 by energizing the stator coil 19 of the stator 17 from the external board through the flexible circuit board and the coil lead-out portion, thereby causing the rotor hub 20 to rotate. It rotates with the shaft 8 as a rotation support shaft. Thereby, the rotor hub 20
The hard disk, which is externally fitted and fixed on the disk mounting surface 22, is driven to rotate integrally with the rotor hub 20.

Next, a manufacturing process for fixing the motor bracket 4 and the shaft 8 in the spindle motor to each other will be described with reference to FIG. As shown in FIG. 2A, the shaft 8 has a diameter r2 slightly smaller than the diameter r1 of the fixing hole 9 of the motor bracket 4.
Is formed. First, the adhesive 3 is applied to the peripheral surface of the fixing hole 9.
After that, the cylindrical portion 13 in which the fixing recess 10 in the shaft 8 is formed is inserted into the fixing hole 9 as shown by an arrow. At this time, since the diameter r2 of the shaft 8 is smaller than the hole diameter r1 of the fixing hole 9, the shaft 8 can be inserted into the fixing hole 9 with little application of pressure.

Subsequently, as shown in FIG. 2B, the shaft 8 inserted into the fixing hole 9 is moved to a predetermined relative position with respect to the motor bracket 4 by using a well-known positioning jig (not shown). The adhesive 3 is cured while maintaining the positioning state. Thereby, the shaft 8 is temporarily fixed to the motor bracket 4 via the cured adhesive 3 in a state where the shaft 8 is accurately positioned. Thereafter, the substantially cylindrical press-fitting member 11 is press-fitted into the fixing recess 10 of the shaft 8 as indicated by an arrow in FIG.

An extruded portion 12 formed at the center of the substantially cylindrical press-fitting member 11 in the cylinder center direction has an outer diameter r3 slightly larger than the hole diameter r4 of the circular fixing recess 10. I have. Thereby, as shown in FIG. 3C, the cylindrical portion 13 around the fixing recess 10 in the shaft 8 is formed.
As the press-fitting member 11 is pressed into the fixing recess 10, the pressing portion 11 is plastically deformed by the extruding portion 12 so as to swell in the radially enlarged direction, and is pressed against the inner surface of the fixing hole 9. As a result, the shaft 8 is firmly connected to the motor bracket 4.

In the means for mutually fixing the motor bracket 4 and the shaft 8 in this spindle motor, the shaft 8 is simply inserted into the fixing hole 9 of the motor bracket 4 and the adhesive 3 hardens to the motor bracket 4. The cylindrical portion 13 of the shaft 8 temporarily fixed to the accurate positioning state is not formed by the press-fitting means, but by the plastic deformation swelling in the radially expanding direction by the press-fitting of the press-fitting member 11 into the fixing recess 13. As shown in FIG. 4C, only a radial residual stress R1 is generated at a position near the shaft 8 in the motor bracket 4 because the shaft 8 is pressed against the peripheral surface. Direction residual stress R2 hardly occurs.

For this reason, the shaft 8 is fixed to the motor bracket 4 by press-fitting the press-fitting member 11 into the fixing recess 10 in a state where the spring-back phenomenon does not act and the shaft 8 is accurately positioned and temporarily fixed. In addition to being able to accurately position and fix the position,
The cylindrical portion 13 of the shaft 8 is fixed to the fixing hole 9 by plastic deformation.
By pressing against the peripheral surface of the motor bracket 1, it is possible to obtain the same fixing strength as when the conventional shaft 2 is press-fitted into the fixing hole 1a of the motor bracket 1 and fixed. This allows
Since the rotor hub 20 for externally fixing the hard disk to the disk mounting surface 22 can be accurately positioned and set at a predetermined height with respect to the reference surface of the motor bracket 4, the rotational runout as a motor can be reduced to a predetermined value. Accuracy can be reliably set.

The substantially cylindrical press-fitting member 11 is
Only the center part is the extruded part 12 having an outer diameter r3 larger than the hole diameter r4 of the fixing recess 10, and the frictional resistance at the time of press-fitting is small, and the hollow part has a slight elasticity inward. By having the property, it is possible to smoothly press-fit the fixing recess 10. Further, there is an advantage that the hollow portion of the pressure member 11 can be used as a wiring space for a coil lead wire or the like.

FIG. 2 is a longitudinal sectional view showing a spindle motor according to a second embodiment of the present invention. In FIG. 2, the same or equivalent parts as those in FIG.
The description is omitted. The only difference between the spindle motor of this embodiment and FIG. 1 is the configuration using a sphere having a diameter r5 slightly larger than the hole diameter r4 of the fixing recess 10 as the press-fitting member 32. By press-fitting the press-fitting member 32 formed of this sphere into the fixing recess 10, the cylindrical portion 13 around the fixing recess 10 in the shaft 8 becomes
It is plastically deformed by the press-fitting member 32 so as to swell in the radially expanding direction and is pressed against the peripheral surface of the fixing hole 9.

Next, a manufacturing process for mutually fixing the motor bracket 4 and the shaft 8 in the spindle motor of the second embodiment will be described with reference to FIG. As shown in FIG. 3A, the shaft 8 is formed to have a diameter r2 slightly smaller than the hole diameter r1 of the fixing hole 9 of the motor bracket 4. First, the adhesive 3 is applied to the peripheral surface of the fixing hole 9, and after that, the cylindrical portion 13 in which the fixing recess 10 is formed in the shaft 8 is inserted into the fixing hole 9 as shown by an arrow. insert. At this time, since the diameter r2 of the shaft 8 is smaller than the hole diameter r1 of the fixing hole 9, the shaft 8 can be inserted into the fixing hole 9 with little application of pressure.

Subsequently, as shown in FIG. 2B, the shaft 8 inserted into the fixing hole 9 is moved to a predetermined position relative to the motor bracket 4 by using a well-known positioning jig (not shown). The adhesive 3 is cured while maintaining the positioning state. Thereby, the shaft 8 is temporarily fixed to the motor bracket 4 via the cured adhesive 3 in a state where the shaft 8 is accurately positioned. After that, the press-fitting member 32 made of a sphere is press-fitted into the fixing recess 10 of the shaft 8 as shown by an arrow in FIG.

The press-fitting member 32 formed of a sphere is formed to have a diameter r5 slightly larger than the hole diameter r4 of the circular fixing recess 10. Thereby, as shown in FIG. 3C, the cylindrical portion 13 of the shaft 8 is
Is plastically deformed by the press-fitting member 32 so as to expand in the radially enlarged direction, and is pressed against the inner surface of the fixing hole 9. Thus, the shaft 8 is firmly connected to the motor bracket 4.

In the means for mutually fixing the motor bracket 4 and the shaft 8 in this spindle motor, the shaft 8 is simply inserted into the fixing hole 9 of the motor bracket 4, and the motor bracket 4 is hardened with the adhesive 3. Cylindrical part 1 of shaft 8 temporarily fixed in the positioning state
3 is not a press-fitting means, but a fixing recess 1 of the press-fitting member 32.
As shown in FIG. 5 (c), the motor bracket 4 is pressed against the peripheral surface of the fixing hole 10 by plastic deformation in the radially expanding direction due to press-fitting into the shaft 3. Only the residual stress R1 is generated, and the residual stress R2 in the thickness direction is hardly generated by not press-fitting the shaft 8.

For this reason, the shaft 8 is fixed to the motor bracket 4 by pressing the press-fitting member 32 into the fixing recess 10 in a state where the spring 8 does not act and when the shaft 8 is accurately positioned and temporarily fixed. In addition to being able to accurately position and fix the position,
The cylindrical portion 13 of the shaft 8 is fixed to the fixing hole 9 by plastic deformation.
By pressing against the peripheral surface of the motor bracket 1, it is possible to obtain the same fixing strength as when the conventional shaft 2 is press-fitted into the fixing hole 1a of the motor bracket 1 and fixed. This allows
Since the rotor hub 20 for externally fixing the hard disk to the disk mounting surface 22 can be accurately positioned and provided at a predetermined height with respect to the reference surface of the motor bracket 4, the rotational runout as a motor can be controlled to a predetermined accuracy. Can be set reliably. Moreover, in this fixing means, since the contact area between the press-fitting member 32 formed of a sphere and the peripheral surface of the fixing recess 10 is small, the press-fitting member 32 is smoothly pressed into the fixing recess 10 and the shaft 8 The cylindrical portion 13 can be easily plastically deformed in the radial direction.

FIG. 3 is a longitudinal sectional view of a main part showing a spindle motor according to a third embodiment of the present invention. This embodiment exemplifies a case in which a notch 33 for drawing out a coil is formed in the vicinity of the fixing hole 9 of the motor bracket 4. Along with that, at the lower end of the shaft 8,
A large-diameter portion 34 having a hole diameter substantially the same as the diameter r5 of the press-fitting member 32 is continuously provided on the opening side with respect to the fixing recess 10 similar to the above-described embodiment, so that the fixing recess 10 and the large-diameter portion 34 Step 37
Is formed. Thereby, in addition to obtaining the same effect as the second embodiment, it is possible to prevent the residual stress R1 in the radial direction from being concentrated in the direction toward the notch 33. This can be prevented from occurring and can be maintained in a vertical state, and deterioration of the rotational runout accuracy of the motor can be prevented.

In each of the above embodiments, the shaft fixed type in which the shaft 8 is fixed to the motor bracket 4 has been described. However, the present invention is configured such that the shaft to which the rotor hub is fixed is rotatably supported by the motor bracket. The same can be applied to the shaft rotation type spindle motor described above. That is, the rotor hub and the shaft are firmly fixed to each other by press-fitting the press-fitting member into the fixing recess provided on the shaft and plastically deforming the cylindrical portion of the shaft so as to expand in the radially enlarged direction. Can be.

[0037]

As described above, according to the spindle motor of the present invention, the mutual fixing structure between the fixed member such as the motor bracket or the rotor hub and the shaft has a smaller diameter than the fixing hole of the fixed member. The shaft is simply inserted without being press-fitted into the fixing hole, and the cylindrical portion of the shaft is plastically deformed in the radially expanding direction by press-fitting the press-fitting member into the fixing recess, so that the shaft is pressed against the peripheral surface of the fixing hole. With this configuration, a residual stress in the thickness direction hardly occurs in the fixed-side member near the shaft by not press-fitting the shaft, so that the springback phenomenon does not act on the shaft. Therefore, the shaft can be accurately positioned and fixed at a predetermined position with respect to the fixed side member, and a required fixing strength can be obtained by pressing the cylindrical portion of the shaft against the peripheral surface of the fixing hole by plastic deformation. be able to. Thus, for example, when used as a rotation drive source for a hard disk, the mounting position of the hard disk can be accurately positioned and set at a predetermined height, so that the rotational runout as a motor can be reliably set to a predetermined accuracy. it can.

According to the spindle motor manufacturing method of the present invention, the shaft simply inserted into the fixing hole of the fixed member is accurately positioned at a predetermined position with respect to the fixed member.
After temporarily fixing the shaft and the fixed-side member by curing the adhesive while maintaining this positioning state, the cylindrical portion of the shaft is expanded in the radially expanding direction by press-fitting into the fixing recess of the press-fitting member. The fixing member is pressed against the peripheral surface of the fixing hole by plastic deformation, so that no residual stress is generated in the fixing-side member in the radial direction of the shaft. Therefore, the shaft is fixed at a predetermined position with respect to the fixed side member by preventing the spring back phenomenon from occurring, and by temporarily pressing the press-fitting member into the fixing recess after temporarily fixing the shaft to an accurate positioning state by curing the adhesive. Can be accurately positioned and fixed.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a spindle motor according to a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional view showing a spindle motor according to a second embodiment of the present invention.

FIG. 3 is a longitudinal sectional view of a main part showing a spindle motor according to a third embodiment of the present invention.

FIG. 4 is a process diagram of a main part showing a method for manufacturing the spindle motor according to the first embodiment of the present invention.

FIG. 5 is a process diagram of a main part showing a method for manufacturing a spindle motor according to a second embodiment of the present invention.

FIG. 6 is a partial process diagram showing a conventional method for manufacturing a spindle motor.

[Explanation of symbols]

 4 Motor bracket (fixed side member) 8 Shaft (shaft) 9 Fixing hole 10 Fixing recess 11 Cylindrical press-fitting member 12 Extruded portion 13 Cylindrical portion (tubular portion) 17 Stator 31 Rotor magnet 32 Spherical press-fitting member 33 Notch 34 Large diameter part 37 Stepped part r1 Hole diameter of fixing hole r2 Shaft diameter r3 Outer diameter of cylindrical press-fitting member r4 Hole diameter of fixing recess r5 Diameter of spherical press-fitting member

Claims (5)

[Claims] 1. A shaft serving as a rotation support shaft is disposed in an upright state at a center portion, a stator is disposed concentrically with respect to the shaft, and a rotor magnet fixed to a rotor is positioned relative to the stator at a predetermined gap. The shaft is a cylindrical body having a diameter smaller than a diameter of a fixing hole of a fixed member fixed to each other, and the shaft is provided at an end surface of the fixed side with an axial center. A fixing recess recessed in the direction and a cylindrical portion surrounding the fixing recess are formed, and have a larger diameter than the fixing recess when the fixing side end is inserted into the fixing hole. Then, the cylindrical portion plastically deformed in the radial direction by the press-fitting member press-fitted into the fixing recess is pressed against the peripheral surface of the fixing hole, and the fixed-side end is in contact with the fixed-side member. Spin characterized by being fixed Dollar motor. 2. The press-fitting member has a substantially cylindrical shape, and has a shape in which an extruded portion bulging to an outer diameter larger than a hole diameter of the fixing recess is provided at least at a central portion in a cylinder center direction thereof. The spindle motor according to claim 1, further comprising: 3. The spindle motor according to claim 1, wherein the press-fitting member is a sphere having a diameter larger than a hole diameter of the fixing recess. 4. A notch is formed in the fixed member formed of a motor bracket in the vicinity of the fixing hole, and the fixing recess is provided at a position of the shaft on the opening side with respect to the fixing recess. 4. The spindle motor according to claim 1, wherein a large diameter portion having a larger diameter is formed, and a step is formed between the fixing recess and the large diameter portion. 5. 5. The method for manufacturing a spindle motor according to claim 1, wherein an adhesive is applied to a peripheral surface of the fixing hole or a peripheral surface of a fixed side end of the shaft. A step of inserting the fixed-side end into the fixing hole and curing the adhesive while maintaining a state where the relative position between the shaft and the fixed-side member is positioned; and a fixing recess of the shaft. Press-fitting a press-fitting member at a location, plastically deforming the cylindrical portion of the shaft so as to expand in a radially expanding direction, and pressing the cylindrical portion into contact with a peripheral surface of a fixing hole. Manufacturing method.