JPH0744990A - Recording medium driving device - Google Patents

Abstract

PURPOSE:To suppress the vibrations of a spindle motor as much as possible, to further realize high rotation accuracy and to increase a recording density to the recording medium by suppressing distortions given to a bearing. CONSTITUTION:A reinforced part 8a by a processing to reduce diamter is provided between first and second and ball bearings 18 and 20. Respective fitting projected parts 12a and 12b projecting upward from the ring part of a ring member 11 are fitted into circumferential direction spaces of the outer peripheral parts 14b1 of the core teeth 14b of a stator core 14. The upper surface of the ring part is brought into contact with the bottom surface of the outer peripheral part 14b1. An annular part among the ring part, the outer peripheral part 14b1, the fitting projected parts 12a and 12b and an annular base 14a is filled with a filling adhesive agent 17 so as to cover the annular base 14a and a stator coil 16. A board 2, the annular base 14a, the core teeth 14b, the ring member 11, the stator coil 16 and the annular base of a flexible circuit board are integrally fixed by solidifying the filling adhesive agent 17.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a stator coil wound around a core tooth protruding radially outward from an annular base portion of a stator core in a spindle motor portion provided on a base, and the annular base portion of the stator core is The present invention relates to a recording medium driving device fitted and fixed to a cylindrical portion provided on a base.

[0002]

2. Description of the Related Art Equipment such as a personal computer including a so-called notebook personal computer is required to be smaller and thinner and have a larger capacity. Therefore, it is inevitably demanded for the recording disk drive devices incorporated therein to be smaller, thinner, and have a larger capacity.

The demand for miniaturization and thinning can be met to some extent by integrally providing the spindle motor, which is separately manufactured and mounted on the base of the disk chamber of the recording disk drive, to the base of the disk chamber. You can

However, in order to meet the demand for large capacity while realizing miniaturization and thinning, the vibration of the spindle motor is prevented as much as possible and a higher rotation accuracy is realized, thereby recording on the recording medium. It is necessary to increase the density if possible.

The present invention has been made in view of the above problems existing in the prior art, and its object is to make the entire apparatus as small and thin as possible.
It is an object of the present invention to provide a recording disk drive device which can prevent vibration of a spindle motor as much as possible, realize higher rotation accuracy, and can be useful in increasing recording density on a recording medium.

[0006]

In order to achieve the above object, in a recording medium driving device of the present invention, a stator coil is wound around a core tooth projecting radially outward from an annular base portion of a stator core. A recording medium driving device in which an annular base portion of a stator core is fitted and fixed to a cylindrical portion provided on a base, and a reinforcing portion by a diameter reduction process is provided in the middle of the cylindrical portion where a pair of ball bearings are mounted. The fitting protrusions provided on the ring member so as to project from the ring portion in the axial direction fit in the circumferential gaps between the outer peripheral portions of the core teeth, and the axial portion of the ring portion is provided on the bottom surface of the outer peripheral portions of the core teeth. One side in the direction is in contact, and the other side in the axial direction of the ring portion is in contact with the base, and the filling adhesive is filled in the space surrounded by the base, the annular base, the core teeth, and the ring member with the annular base and the stator. Filled to cover the top surface of the coil, , Sutetetakoa, stator coils and the ring member, it is assumed that was integrally fixed by its filling adhesive.

[0007]

[Operation] In the circumferential gap between the outer peripheral portions of the core teeth in the stator core fitted and fixed to the cylindrical portion provided on the base,
The fitting convex portion that is provided so as to project from the ring portion of the ring member in the axial direction is fitted, and one side of the ring portion in the axial direction is in contact with the bottom surface of the outer peripheral portion of the core tooth, and the other side of the ring portion in the axial direction is Since the base is in contact with the base, the space surrounded by the base, the annular base, the core teeth, and the ring member can be easily filled with the filling adhesive and solidified as it is. In this case, the filling adhesive is filled so as to cover the upper surfaces of the stator coil and the annular base portion. The height of the annular peripheral wall portion and the fitting convex portion in the axial direction is set higher than the upper surfaces of the stator coil and the annular base portion so that the filling adhesive does not flow out. A reinforcing portion by a diameter reduction process is provided in the middle of the cylindrical portion in which the pair of ball bearings are mounted so that the cylindrical portion is less likely to be deformed even when a contracting force due to the curing of the filling adhesive is applied.

The fitting protrusions of the ring member are fitted in the circumferential gaps between the outer peripheral portions of the core teeth, and the annular base portion of the stator core is fitted and fixed to the annular peripheral wall portion of the base, and the base, the stator core, the stator coil, and Since the ring member is integrally fixed by the filling adhesive, the rigidity of the stator core is increased together with the rigidity of the ring member and the base, and thereby the natural frequency of the stator core is also increased.

[0009]

Embodiments of the present invention will be described with reference to the drawings. 1 to 5 relate to a hard disk drive device as one embodiment of the present invention, in which FIG. 1 is a plan view showing a state in which a lid of a disk chamber is removed.
Is a cross-sectional view taken along the line II-P-Q-S-II in FIG. 1, FIG. 3 is a plan view of the ring member, and FIG. 4 is a main part plan view of a state in which the stator fitted with the ring member is attached to the base. , Fig. 5
FIG. 5 is a sectional view taken along line VV in FIG. 4. Needless to say, the recording medium driving device of the present invention is not limited to a hard disk.

Reference numeral 2 denotes a base of a hard disk drive, 4
Is a lid of the disc chamber 3. The base 2 has a horizontally long rectangular shape in FIG. 1, and the base 2 is provided with an annular recess 6 that is open to the disk chamber 3 side with its center leftward as the center. A cylindrical portion 8 protruding concentrically with the annular recess 6 from the inner peripheral portion of the bottom of the annular recess 6 constitutes the inner peripheral wall of the annular recess 6. The inner peripheral portion of the cylindrical portion 8 is a through portion.

As shown in FIGS. 3 and 5, the ring member 11 comprises an annular ring portion 10 and fitting projections 12a and 12b projecting upward from the ring portion 10 in the axial direction. The material of the ring member 11 is preferably a heat resistant synthetic resin (for example, PPS having a heat resistant temperature of 220 ° C.). The fitting protrusions 12a and 12b are provided at nine locations for each 40-degree center angle. Five of them are provided with fitting protrusions 12a protruding only upward in the axial direction, and the remaining four are
A fitting protrusion 12b is provided that includes an upper protrusion 12b1 protruding upward in the axial direction and an expanding portion 12b2 protruding further inward in the radial direction and expanding in the circumferential direction. These two types of fitting protrusions 12a and 12b are alternately arranged except that the fitting protrusion 12a on the right side in FIG. 3 is continuous.

The annular base portions 14a to 9 of the stator core 14
A stator coil 16 is wound around each of the core teeth 14b protruding radially outward in a rotationally symmetrical manner. The outer peripheral portion 14b1 of the core tooth 14b is widened to both sides in the circumferential direction. The fitting protrusions 12a and 12b of the ring member 11 are fitted in the circumferential gap between the outer peripheral portions 14b1 and the outer peripheral portion 14b.
The top surface of the ring portion 10 is in contact with the bottom surface of the ring 1. Therefore, the side surface of the fitting convex portion 12a and the side surface of the upper convex portion 12b1 of the fitting convex portion 12b are in contact with the side surface of the outer peripheral portion 14b1. The upper surfaces of the fitting protrusions 12a and 12b and the upper surface of the outer peripheral portion 14b1 have the same height, and are higher than the upper surface of the stator coil 16.

In the case of this embodiment, the expanding portions 1 in the four fitting convex portions 12b separated by the central angle of 80 degrees or 120 degrees.
The outer peripheral surface of 2b2 comes into contact with the inner peripheral surface of the portion of the outer peripheral portion 14b1 of the two adjacent core teeth 14b which is expanded in the circumferential direction. Therefore, by attaching the ring member 11 to the stator core 14 as described above, the center alignment of the ring member 11 and the stator core 14 is performed by itself.

The flexible circuit board 68 has an annular portion 68.
b, and a drawer portion 68a extending outward from one end thereof. The outer diameter of the annular portion 68b is slightly smaller than the inner diameter of the ring portion 10 of the ring member 11, and the outer peripheral portion 14b1 of the annular portion 68b has a cutout portion 90 corresponding to the expanded portion 12b2 of the fitting projection 12b. Has been done.

When the flexible circuit board 68 is attached to the lower surface of the stator coil 16, the flexible circuit board 6 is used.
In the terminal area 92 provided on the upper surface of the stator coil 1
The lead-out portions 6 (not shown) are connected by soldering, and the cutout portions 90 are provided with the expanded portions 12b of the ring member 11.
Position it according to.

In this way, the stator core 14 to which the ring member 11 and the flexible circuit board 68 are attached
Is the outer peripheral portion 14 of the cylindrical portion 8 at the annular base portion 14a.
The ring member 11 is externally fitted and fixed to b1 (annular peripheral wall portion), and the lower surface of the ring member 11 is in contact with the upper surface of the base 2 with the pull-out portion 68a sandwiched in between. At that time, the flexible circuit board 68
By aligning the lead-out portion 68a of the stator core 14 with the guide groove 69 that extends from the bottom of the annular recess 6 to the outside in the radial direction via the outer peripheral surface portion, the circumferential rotation angle of the stator core 14 with respect to the base 2 is positioned.

In the annular concave portion 6, the annular portion between the ring portion 10, the outer peripheral portion 14b1 and the fitting convex portions 12a and 12b, and the annular base portion 14a is filled with the filling adhesive 17 (filling agent) from each slot of the stator core 14. And those having both the functions of adhesive and thermosetting are preferable from the viewpoint of heat resistance.
For example, a material that is heated to about 100 ° C. and cured. ) Is filled so as to cover the upper surfaces of the stator coil 16 and the annular base portion 14a. In addition, the filling adhesive 17 is applied to the outer peripheral portion 14b.
The height of the upper surfaces of the outer peripheral portion 14b1 and the fitting projections 12a and 12b is made higher than the upper surfaces of the stator coil 16 and the annular base portion 14a so as not to flow out from the outside. Base 2, annular base 14a, core teeth 14b, ring member 1
1. Stator coil 16 and flexible circuit board 68
The annular portion 68b is integrally fixed by solidifying the filling adhesive 17.

Insulating paper (not shown) is arranged between the flexible circuit board 68 and the stator core 14. The insulating paper is sized to fit inside the annular peripheral wall portion 14b1, and is shaped so as to cover the annular base portion 14a of the stator core 14 and the lower surfaces of the core teeth 14b. Insulating paper consists of a base 2 and an annular base 14.
Since the space surrounded by a, the core teeth 14b, and the ring member 11 is not covered, fixing with the filling adhesive 17 is sufficient.

A gap between the bottom surface of the outer peripheral portion 14b1 and the upper surface of the ring portion 10, and the fitting protrusion 12a or the upper protrusion 12b.
The gap between the side surface of No. 1 and the side surface of the outer peripheral portion 14b1 is such that the filling adhesive 17 enters into these gaps to bond the two and does not flow out (depending on the physical properties such as viscosity of the filling adhesive, It is desirable to set the thickness to, for example, about 0.1 mm, but it is acceptable if it is small enough not to leak from the gap.

Outer peripheral portion 1 of core tooth 14b of stator core 14 fitted and fixed to cylindrical portion 8 provided on base plate 2
The fitting protrusions 12a axially protruding from the ring portion 10 of the ring member 11 and the upper protrusions 12b1 of the fitting protrusions 12b are fitted into the circumferential gap between the four teeth 4b1 and the core teeth 14b.
Since the upper surface of the ring portion 10 is in contact with the bottom surface of the outer peripheral portion 14b1 and the lower surface of the ring portion 10 is in contact with the base 2,
The space surrounded by the base 2, the annular base portion 14a, the core teeth 14b, and the ring member 11 can be easily filled with the filling adhesive 17 and solidified as it is. The filling adhesive 17 is filled so as to cover the upper surfaces of the stator coil 16 and the annular base portion 14a. Further, as compared with the case where the fitting protrusions 12a and 12b are integrally formed on the base 2, the base 2 is easier to process, so that the manufacturing efficiency is high as a whole.

The fitting convex portion 12a of the ring member 11 and the upper convex portion 12b1 of the fitting convex portion 12b are fitted into the circumferential gap between the outer peripheral portions 14b1 of the core teeth 14b, and the cylindrical portion 8 of the base 2 is fitted.
On the other hand, the annular base portion 14a of the stator core 14 is fitted and fixed, and the base 2, the stator core 14, the ring member 11, the stator coil 16, and the annular portion 68b of the flexible circuit board 68 are integrally fixed by the filling adhesive 17. Therefore, the rigidity of the stator core 14 depends on the ring member 1
It is increased together with the rigidity of the base 1 and the base 2. Stator core 1
Since the filling adhesive 17 is filled and solidified over the entire circumference of 4, the effect is great. As a result, the natural frequency of the stator core 14 is also increased, and the occurrence of resonance is satisfactorily prevented. Therefore, vibration is effectively suppressed, which greatly contributes to the improvement of rotation accuracy, and in increasing the recording density on the recording medium. It is valid.

Further, as in this embodiment, the ring member 11
Is formed of a non-metallic material, the fitting protrusions 12a, 12
Unlike the case where b and the ring portion 10 are made of metal, the occurrence of overcurrent loss and hysteresis loss during motor driving is prevented, and good current characteristics are realized.

Reference numeral 18 is a first ball bearing, and 20 is a second ball bearing. The outer rings of the first ball bearing 18 and the second ball bearing 20 are fixed to the inner peripheral wall of the cylindrical portion 8 with an adhesive.

A small diameter portion 8a having a smaller diameter is provided radially inward in a portion between the first ball bearing 18 and the second ball bearing 20 mounted on the cylindrical portion 8. The small diameter portion 8a reinforces the cylindrical portion 8 and prevents the first ball bearing 18 and the second ball bearing 20 from being distorted by the contracting force generated when the filling adhesive 17 is cured.

Reference numeral 22 is a rotor hub. Rotor hub 22
A rotary shaft 24 is provided at the center of the
Inner rings of the first ball bearing 18 and the second ball bearing 20 are fixed to the outer peripheral surface of the adhesive 4 by an adhesive. As a result, the rotor hub 22 is supported concentrically with the annular recess 6 and rotatably with respect to the base 2. At the lower end of the outer peripheral wall of the rotor hub 22, an overhanging portion 26 for supporting the lower surface of the inner circumferential portion of the hard disk is provided. Below the overhanging portion 26, an annular holding plate 28 for holding a rotor magnet is provided. The inner circumference of is fixed. The holding annular plate 28 and the rotor hub 22 form a rotor frame. An outer peripheral portion of the holding annular plate 28 has a hanging portion 28a holding an annular rotor magnet 30 inside, and the hanging portion 28a and the annular recess 6 face each other with a slight radial gap. . The rotor magnet 30 and the stator core 14 face each other with a radial gap. The holding annular plate 28 is made of a soft magnetic material and serves as a yoke of the rotor magnet 30 and a magnetic shield plate.

The hanging portion 28a of the holding annular plate 28, the rotor magnet 30 (field means), the stator core 14 and the stator coil 16 (armature) are housed substantially in the annular recess 6. Then, the cylindrical portion 8 and the rotor hub 2
2, the holding annular plate 28, the stator core 14, the rotor magnet 30, the hanging portion 28a and the like, and the annular recess 6 provide a labyrinth seal effect, and lubricant fine particles for the first ball bearing 18 and the second ball bearing 20. Are prevented from scattering in the disk chamber 3. Further, an annular groove portion 38, which is formed between the holding annular plate 28 and the rotor magnet 30 and has a radially inward opening, stores lubricant fine particles and the like from the first ball bearing 18 and the second ball bearing 20. The effect of preventing scattering in the disk chamber 3 is exhibited.

Reference numeral 40 is a sealing member for sealing the lower end of the inner peripheral portion of the cylindrical portion 8 serving as a penetrating portion.

The annular recess 6, the cylindrical portion 8 and the first ball bearing 1
8, second ball bearing 20, rotor hub 22, stator core 1
4, the stator coil 16, the holding annular plate 28, the rotor magnet 30, and the like constitute a spindle motor unit A for driving a hard disk. The annular recess 6 that is the stator frame of the spindle motor unit A has the base 2
Since it is integrally provided in the device, the height of the entire device can be kept low.

A hard disk 42 is attached to the rotor hub 22.
Is externally fitted, and the lower surface of the inner peripheral portion 42 a of the hard disk 42 is supported on the upper surface of the protruding portion 26. Reference numeral 44 denotes a clamp member for holding the inner peripheral portion of the hard disk 42 between itself and the overhanging portion 26 under pressure, and its outer diameter is substantially equal to the outer diameter of the overhanging portion 26. The clamp member 44 is screwed to the upper end of the rotor hub 22.

The overhanging portion 26 and the clamp member 44 constitute a disc holding portion. The outer diameter of the annular recess 6 is twice the outer diameter of the overhanging portion 26 and the clamp member 44,
The outer diameter of the hard disk 42 is less than three times the outer diameter of the overhanging portion 26 and the clamp member 44. Hard disk 4
The outer periphery of 2 is located slightly inside the outer edge of the base 2.

The bottom surface of the hard disk 42 (side surface of the base 2)
Between the and the holding annular plate 28, there is a gap through which the lower one of the magnetic heads 46 arranged on the upper and lower surfaces of the hard disk 42 can go in and out.

In FIG. 1, all of the outer wall portion of the annular recess 6 and almost the radially outer portion of the annular recess 6 on the left side of the center of the annular recess 6 in the longitudinal direction of the base plate 2 and the right end thereof. All are formed in the 1st convex part 48 of a fixed height which has a slight gap with which the magnetic head 46 cannot move in and out with the lower surface of the hard disk 42.

All of the outer wall portion of the annular recess 6 of the base 2 except the first protrusion 48 and most of the radially outer portion thereof except the head positioning mechanism recess 56 are located on the lower surface of the hard disk 42. The magnetic head 46 is formed in the second convex portion 58 having a height that allows the magnetic head 46 to move in and out. The head positioning mechanism recess 56 is located at the front right portion in FIG. 1, and its height is between the bottom surface of the annular recess 6 and the top surface of the second protrusion 58, as shown in FIG.

There is a gap between the lower surface of the hard disk 42 and the upper surface of the holding annular plate 28 so that the magnetic head 46 can move in and out, and the first convex portion 48 of the outer wall portion of the annular concave portion 6 of the base 2 is provided. All other parts are formed on the second convex portion 58 through which the magnetic head 46 can move in and out of the gap with the lower surface of the hard disk 42, so that the range in which the magnetic head 46 can be positioned on both sides of the hard disk 42 is the overhanging part. From the outer peripheral position of 26 to the outer peripheral position of the hard disk 42 via the outer peripheral position of the annular concave portion 6, it is wider than the difference between the outer diameter of the hard disk 42 and the outer diameter of the spindle motor portion A, that is, the outer diameter of the holding annular plate 28. .

Reference numeral 60 is a pivot assembly fixed in the head positioning mechanism recess 56, and is a magnetic head 4
An arm 62 for holding a voice coil 6 and a voice coil (not shown) at the tip and the base, respectively, is rotatably supported on the base 2. Reference numeral 64 is a yoke of a voice coil motor for rotating the arm 62 to position the magnetic head 46, and 66 is a guide pin provided on the base 2 for positioning the yoke 64. As the lubricant for the ball bearing (not shown) used in the pivot assembly 60, it is preferable to use oil rather than grease. This is for suppressing the variation in effective torque due to the voice coil motor and improving the positioning accuracy of the magnetic head 46.

Draw-out portion 68 of flexible circuit board 68
The tip of a is fixed on the front end 70a of the connector 70 fixed to the right rear part of the base 2 in FIG. 1, and the circuit is connected to the connector pin 72 by soldering. The front end portion 70a of the connector 70 is formed slightly lower than the other portions of the connector 70 in order to secure the height of the solder by soldering the lead-out portion 68a while suppressing the overall height.

Reference numeral 74 is a fitting hole penetrating the base 2.
A through hole 68a1 is provided at a position corresponding to the fitting hole 74 in the drawer portion 68a. Reference numeral 78 is a lifting prevention member. FIG. 6 is an enlarged plan view of the lifting prevention member 78. The lifting prevention member 78 is formed by bending a plate-shaped member in response to a change in height from the bottom and outer peripheral surface of the annular recess 6 to the second protrusion 58, and corresponds to the fitting hole 74. Position, the downward fitting protrusion 8
0 is provided.

The fitting convex portion 80 penetrates through the through hole 68a1 of the drawer portion 68a and fits into the fitting hole 74, and the floating prevention member 78 is fixed to the substrate 2 so that the flexible circuit board 68 is pulled out. The annular recess 6 of the portion 68a
At least the hard disk 42 from the bottom and the outer peripheral surface of the
It is prevented that the portion extending over the outer peripheral position of the is lifted from the base 2. Accordingly, it is possible to easily and surely prevent the disconnection of the conduction path of the pull-out portion 68a, the rotation of the rotor hub 22, and the obstruction of the movement of the magnetic head 46.

The upper and lower positional relationships in the above description of the embodiments are merely for convenience of description based on the drawings, and do not limit the actual usage conditions.

[0040]

In the recording medium driving device of the present invention, the base, the annular base and the core formed by fitting the ring member and the stator core and fitting the annular base of the stator core to the annular peripheral wall of the base. A filling adhesive can be filled and solidified in a space surrounded by the teeth and the ring member so as to cover the upper surfaces of the stator coil and the annular base portion. By providing the reinforcing portion in the middle of the cylindrical portion in which the pair of ball bearings are mounted, it is possible to prevent the bearing from being distorted by the contracting force accompanying the curing of the filling adhesive. Further, as compared with the case where the fitting convex portion is integrally formed on the base, the base is easier to process, so that the manufacturing efficiency is high as a whole.

Further, the fitting protrusion of the ring member is fitted to the circumferential gap between the outer peripheral portions of the core teeth, the fitting and fixing of the annular base portion of the stator core to the annular peripheral wall portion of the base, and the filling adhesive. By at least integrally fixing the base, the stator core, the stator coil, and the ring member, the rigidity of the stator core is increased together with the rigidity of the ring member and the base. As a result, the natural frequency of the stator core is increased and resonance is well prevented,
The vibration is effectively suppressed, which largely contributes to the improvement of the rotation accuracy, and is effective in increasing the recording density on the recording medium.

[Brief description of drawings]

FIG. 1 is a plan view showing a state in which a lid of a disc chamber is removed.

FIG. 2 is a sectional view taken along line II-P-Q-S-II in FIG.

FIG. 3 is a plan view of a ring member.

FIG. 4 is a plan view of an essential part of a state where a stator fitted with a ring member is attached to a base.

5 is a sectional view taken along line VV in FIG.

FIG. 6 is an enlarged plan view of a lifting prevention member.

[Numerical reference numeral] 2 base 8 cylindrical portion 8a small diameter portion 10 ring portion 11 ring member 12a fitting convex portion 12b fitting convex portion 14 stator core 14a annular base portion 14b core tooth 14b1 outer peripheral portion 16 stator coil 17 filling adhesive 18 first Ball bearing 20 Second ball bearing

Claims (1)

[Claims] 1. A recording in which a stator coil is wound around a core tooth projecting radially outward from an annular base portion of a stator core, and the annular base portion of the stator core is fitted and fixed to a cylindrical portion provided on a base. A medium drive device for use with a pair of ball bearings, wherein a cylindrical reinforcing portion is provided in the middle of the cylindrical portion, and a fitting convex portion projecting in the axial direction from the ring portion of the ring member forms a core. Fits in the circumferential gap between the outer peripheral parts of the teeth, one side of the ring part in the axial direction is in contact with the bottom surface of the outer peripheral part of the core tooth, and the other side of the ring part in the axial direction is in contact with the base. A filling adhesive is filled in the space surrounded by the annular base, the core teeth, and the ring member so as to cover the upper surface of the annular base and the stator coil, and the base, the stator core, the stator coil, and the ring member are filled and bonded. Depending on the agent Recording medium driving apparatus characterized by being secured.