JP3424688B2 - Recording medium drive - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spindle motor in which a stator coil is provided on core teeth projecting radially outward from an annular base of a stator core in a spindle motor provided on a base. The present invention relates to a recording medium driving device that is wound and has an annular base portion of a stator core fitted and fixed to a cylindrical portion provided on a base. 2. Description of the Related Art Devices such as a personal computer such as a so-called notebook computer are increasingly required to be smaller, thinner, and larger in capacity. For this reason, there is also a strong demand for a recording disk drive incorporated therein to be smaller, thinner, and have a larger capacity. The demand for miniaturization and thinning has been met to some extent by providing a spindle motor, which was separately manufactured and assembled on the base of the disk chamber in the recording disk drive, integrally with the base of the disk chamber. Can be. [0004] However, in order to meet the demand for large capacity while realizing miniaturization and thinning, recording on a recording medium is performed by preventing vibration of the spindle motor as much as possible and realizing higher rotational accuracy. It is necessary to be able to increase the density. The present invention has been made in view of the above-mentioned problems in the prior art, and has as its object to reduce the size and thickness of the entire apparatus as much as possible.
It is an object of the present invention to provide a disk drive for recording that can prevent vibration of a spindle motor as much as possible, realize higher rotational accuracy, and increase recording density on a recording medium. In order to achieve the above object, a recording medium driving apparatus according to the present invention comprises a stator core ring.
A plurality of core teeth projecting radially outward from the base
Stator coils are wound around the stator core, respectively.
A base is provided on the base, and a pair of ball bearings are internally fitted and fixed
The outer periphery of the stator core and the base
Recording medium in which a ring member is attached to a disk
A driving device, wherein a middle portion of the cylindrical portion is supplemented by diameter reduction processing.
A strong portion, wherein the ring member comprises a ring portion;
A circumferential gap between the outer peripheral portions of the core teeth protruding in the axial direction of
A plurality of fitting projections provided to fit into
And one side of the ring portion in the axial direction is the outer periphery of the core tooth.
Contact the bottom surface of the ring, and the other axial side of the ring
The mounting adhesive is attached to the base and the filling adhesive is
Surrounded by a disk, the annular base, the core teeth and the ring member.
The annular base and the upper surface of the stator coil in a surrounded space
And the base, the stator core, the
The stator coil and the ring member are integrally fixed . [0007] The circumferential gap between the outer peripheral portions of the core teeth of the stator core fitted and fixed to the cylindrical portion provided on the base,
A fitting protrusion protruded in the axial direction from the ring portion of the ring member is fitted, one side of the ring portion in the axial direction contacts the bottom surface of the outer peripheral portion of the core teeth, and the other side in the axial direction of the ring portion is Since it is in contact with the base, the filling adhesive can be easily filled and solidified in the space surrounded by the base, the annular base, the core teeth, and the ring member 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. The height of the annular peripheral wall portion and the fitting protrusion in the axial direction is higher than the upper surfaces of the stator coil and the annular base portion so that the filling adhesive does not flow outside. In order to prevent the cylindrical portion from being deformed even if a shrinkage force due to the curing of the filling adhesive is applied, a reinforcing portion is provided in the middle of the cylindrical portion on which the pair of ball bearings is mounted by reducing the diameter. The fitting projection of the ring member fits into the circumferential gap between the outer peripheral portions of the core teeth, the annular base of the stator core is fitted and fixed to the annular peripheral wall of the base, and the base, stator core, 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, thereby increasing the natural frequency of the stator core. An embodiment of the present invention will be described with reference to the drawings. 1 to 5 show a hard disk drive as an embodiment of the present invention. FIG. 1 is a plan view showing a state where a cover of a disk chamber is removed, and FIG.
Is a cross-sectional view taken along the line II-PQS-II in FIG. 1, FIG. 3 is a plan view of a ring member, and FIG. 4 is a plan view of a main part in a state where a stator in which the ring member is fitted is attached to a base. , FIG.
FIG. 5 is a sectional view taken along line VV in FIG. 4. Needless to say, the recording medium drive of the present invention is not limited to a hard disk drive. 2 is the base of the hard disk drive, 4
Is a lid of the disk chamber 3. The base 2 has a horizontally long flat rectangular shape in FIG. 1, and has an annular concave portion 6 opening toward the disk chamber 3 with the center on the left side of the center. A cylindrical portion 8 projecting concentrically from the annular concave portion 6 upward from the bottom inner peripheral portion of the annular concave portion 6 forms an inner peripheral wall of the annular concave portion 6. The inner peripheral portion of the cylindrical portion 8 is a penetrating 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 with a heat-resistant temperature of 220 ° C.). The fitting protrusions 12a and 12b are provided at nine positions for each central angle of 40 degrees. At five of them, fitting projections 12a protruding only upward in the axial direction are provided, and at the remaining four locations,
A fitting projection 12b is provided which includes an upper projection 12b1 projecting upward in the axial direction, and an expanding portion 12b2 which further projects radially inward and expands in the circumferential direction. These two types of fitting projections 12a and 12b are alternately arranged except that the right fitting projection 12a on the right side in FIG. 3 is continuous. The annular bases 14a to 9 of the stator core 14
A stator coil 16 is wound around each of the core teeth 14b projecting radially outward in a rotationally symmetric manner. The outer peripheral portion 14b1 of the core tooth 14b is expanded on both sides in the circumferential direction. Each of the fitting projections 12a and 12b of the ring member 11 fits in the circumferential gap between the outer peripheral portions 14b1, and
The upper surface of the ring portion 10 is in contact with the bottom surface of the ring 1. Therefore, the side surface of the fitting protrusion 12a and the side surface of the upper protrusion 12b1 of the fitting protrusion 12b are in contact with the side surface of the outer peripheral portion 14b1. The upper surfaces of the fitting projections 12a and 12b and the outer surface 14b1 have the same height, and are higher than the upper surface of the stator coil 16. In the case of this embodiment, the expanded portions 1 at the four fitting projections 12b separated by a central angle of 80 degrees or 120 degrees.
The outer peripheral surface of 2b2 is in contact with the inner peripheral surface of the portion of the outer peripheral portion 14b1 of the two adjacent core teeth 14b that is expanded in the circumferential direction. Therefore, by attaching the ring member 11 to the stator core 14 as described above, the centering 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 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 enlarged portion 12b2 of the fitting convex portion 12b. Have been. When the flexible circuit board 68 is attached to the lower surface of the stator coil 16, the flexible circuit board 6
8 is connected to a terminal region 92 provided on the upper surface of the stator coil 1.
6 is connected by soldering, and the cutout portion 90 is connected to the expanded portion 12 b of the ring member 11.
Positioning corresponding to. The stator core 14 to which the ring member 11 and the flexible circuit board 68 are attached in this manner.
Is the outer peripheral portion 14 of the cylindrical portion 8 at the annular base portion 14a.
The lower surface of the ring member 11 is partially in contact with the upper surface of the base 2 with the drawer portion 68a interposed therebetween. At this time, the flexible circuit board 68
Of the stator core 14 with respect to the base 2 in the circumferential direction by positioning the lead portion 68a along the guide groove 69 extending radially outward from the bottom of the annular concave portion 6 through the outer peripheral surface portion. In the annular concave portion 6, a filling adhesive 17 (filling agent) is inserted from each slot of the stator core 14 into an annular portion between the ring portion 10, the outer peripheral portion 14b1, the fitting convex portions 12a and 12b, and the annular base portion 14a. It has both functions of an adhesive and an adhesive, and is preferably a thermosetting material in terms of heat resistance.
For example, those cured by heating to about 100 ° C. ) Is filled so as to cover the upper surfaces of the stator coil 16 and the annular base 14a. The filling adhesive 17 is applied to the outer peripheral portion 14b.
The height of the outer peripheral portion 14b1 and the upper surface of the fitting projections 12a, 12b is 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
Is fixed integrally by solidification of the filling adhesive 17. An insulating paper (not shown) is arranged between the flexible circuit board 68 and the stator core 14. The insulating paper has a size that can be accommodated in the annular peripheral wall portion 14b1 and has a shape that covers the annular base portion 14a of the stator core 14 and the lower surface of the core teeth 14b. The insulating paper is composed of the base 2 and the annular base 14.
a, the core teeth 14b, and the space surrounded by the ring member 11 do not cover the space, so that the fixing with the filling adhesive 17 is sufficient. The gap between the bottom surface of the outer peripheral portion 14b1 and the upper surface of the ring portion 10, and the fitting projection 12a or the upper projection 12b
The gap between the side surface 1 and the side surface of the outer peripheral portion 14b1 is such that the filling adhesive 17 enters the gap and adheres to each other and does not flow out (depending on the physical properties such as the viscosity of the filling adhesive, For example, it is desirable to set the thickness to about 0.1 mm. Outer peripheral portion 1 of core teeth 14b of stator core 14 fitted and fixed to cylindrical portion 8 provided on base 2
The fitting protrusions 12a and the upper protrusions 12b1 of the fitting protrusions 12b projecting in the axial direction from the ring portion 10 of the ring member 11 are fitted in the circumferential gaps between the ring 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,
In a space surrounded by the base 2, the annular base 14a, the core teeth 14b, and the ring member 11, the filling adhesive 17 can be easily filled 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 14a. Further, as compared with the case where the fitting protrusions 12a and 12b are formed integrally with the base 2, the processing of the base 2 is easier, and thus the manufacturing efficiency as a whole is higher. The fitting protrusions 12a of the ring member 11 and the upper protrusions 12b1 of the fitting protrusions 12b are fitted in the circumferential gap between the outer peripheral portions 14b1 of the core teeth 14b, and the cylindrical portion 8 of the base 2 is formed.
The base 2, the stator core 14, the ring member 11, the stator coil 16, and the annular portion 68 b of the flexible circuit board 68 are integrally fixed by the filling adhesive 17. Therefore, the rigidity of the stator core 14 is
1 and the rigidity of the base 2 are increased. Stator core 1
The effect is great because the filling adhesive 17 is filled and solidified over the entire circumference of No. 4. As a result, the natural frequency of the stator core 14 is also increased, and the occurrence of resonance is favorably prevented, so that the vibration is effectively suppressed, which greatly contributes to the improvement of the rotation accuracy, and the recording density with respect to the recording medium is increased. It is valid. Also, as in this embodiment, the ring member 11
Is formed of a non-metallic material, the fitting projections 12a and 12
Unlike the case where b and the ring portion 10 are formed of metal, occurrence of overcurrent loss and hysteresis loss during driving of the motor is prevented, and good current characteristics are realized. Reference numeral 18 denotes a first ball bearing, and reference numeral 20 denotes 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. At a portion between the first ball bearing 18 and the second ball bearing 20 mounted on the cylindrical portion 8, a small diameter portion 8a having a smaller diameter is provided radially inward. 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 due to the contraction force generated when the filling adhesive 17 hardens. Reference numeral 22 denotes a rotor hub. Rotor hub 22
A rotary shaft 24 protrudes from a central portion of the rotary shaft 2.
The inner races of the first ball bearing 18 and the second ball bearing 20 are fixed to an outer peripheral surface of the fourth ball bearing 4 with an adhesive. Thereby, the rotor hub 22 is supported concentrically with the annular recess 6 and rotatably with respect to the base 2. An extended portion 26 for supporting the lower surface of the inner peripheral portion of the hard disk is provided at a lower end portion of the outer peripheral wall of the rotor hub 22, and a holding annular plate 28 for retaining the rotor magnet is provided below the extended portion 26. Is fixed at its inner periphery. The holding annular plate 28 and the rotor hub 22 constitute a rotor frame. An outer peripheral portion of the holding annular plate 28 has a hanging portion 28a holding the annular rotor magnet 30 inside, and the hanging portion 28a and the annular concave portion 6 are opposed to each other with a slight radial gap. . The rotor magnet 30 and the stator core 14 face each other with a radial gap therebetween. The holding annular plate 28 is made of a soft magnetic material, and also serves as a yoke of the rotor magnet 30 and a magnetic shield plate. The hanging portion 28 a 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, the rotor hub 2
2. The labyrinth sealing effect is obtained by the holding annular plate 28, the stator core 14, the rotor magnet 30, the hanging portion 28a, and the like, and the annular concave portion 6, and the lubricant fine particles of the first ball bearing 18 and the second ball bearing 20 are obtained. Is prevented from scattering into the disk chamber 3. Further, an annular groove 38 having a radially inward opening formed between the holding annular plate 28 and the rotor magnet 30 stores lubricant particles and the like from the first ball bearing 18 and the second ball bearing 20. This has the effect of preventing scattering in the disk chamber 3. Reference numeral 40 denotes a sealing member for sealing the lower end of the inner peripheral portion of the cylindrical portion 8 which is a penetrating portion. The above-mentioned annular concave portion 6, cylindrical portion 8, first ball bearing 1
8, second ball bearing 20, rotor hub 22, stator core 1
4, a spindle motor unit A for driving a hard disk is constituted by the stator coil 16, the holding annular plate 28, the rotor magnet 30, and the like. The annular recess 6 which is the stator frame of the spindle motor section A is
, The height of the entire apparatus can be kept low. The rotor hub 22 has a hard disk 42
The lower surface of the inner peripheral portion 42 a of the hard disk 42 is supported on the upper surface of the overhang portion 26. Reference numeral 44 denotes a clamp member for holding the inner peripheral portion of the hard disk 42 between the overhang portion 26 and the clamping portion, and its outer diameter is substantially equal to the outer diameter of the overhang portion 26. The clamp member 44 is screwed to the upper end of the rotor hub 22. The overhang portion 26 and the clamp member 44 constitute a disk holding portion. The outer diameter of the annular recess 6 is more than twice the outer diameter of the overhang 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 overhang 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. Lower surface of hard disk 42 (side surface of base 2)
There is a gap between the magnetic head 46 disposed on the upper and lower surfaces of the hard disk 42 so that the lower magnetic head 46 can enter and exit between the upper surface of the holding annular plate 28 and the upper surface of the holding annular plate 28. In FIG. 1, the entire outer wall portion of the annular concave portion 6 and the radially outer portion of the outer peripheral portion of the annular concave portion 6 on the left side of the center of the annular concave portion 6 and the right end thereof in the longitudinal direction of the base 2 are almost completely separated. All of them are formed on a first convex portion 48 having a constant height and a small gap between the lower surface of the hard disk 42 and the magnetic head 46 so that the magnetic head 46 cannot enter or exit. The entire outer wall portion of the annular concave portion 6 of the base 2 except for the first convex portion 48 and most of the radially outer portion of the outer peripheral portion except the concave portion 56 for the head positioning mechanism are in contact with the lower surface of the hard disk 42. The magnetic head 46 is formed on a second convex portion 58 having a height at which the magnetic head 46 can enter and exit. The recess 56 for the head positioning mechanism 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 projection 58 as shown in FIG. 2. There is a gap between the lower surface of the hard disk 42 and the upper surface of the holding annular plate 28, through which the magnetic head 46 can enter and exit, and the first convex portion 48 of the outer wall of the annular concave portion 6 in the base 2. Are formed on the second convex portions 58 through which the magnetic head 46 can enter and exit from the lower surface of the hard disk 42. Therefore, the range in which the magnetic head 46 can be positioned on both surfaces of the hard disk 42 is From the outer peripheral position of 26 to the outer peripheral position of the hard disk 42 through 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 denotes a pivot assembly fixed to the recess 56 for the head positioning mechanism.
6 and an arm 62 that holds a voice coil (not shown) at the distal end and the base, respectively, is rotatably supported on the base 2. 64 is a yoke of a voice coil motor for positioning the magnetic head 46 by rotating the arm 62, and 66 is a guide pin provided on the base 2 for positioning the yoke 64. As a lubricant for a ball bearing (not shown) used for the pivot assembly 60, it is preferable to use oil rather than grease. This is to suppress the variation of the effective torque due to the voice coil motor and increase the positioning accuracy of the magnetic head 46. The drawing section 68 of the flexible circuit board 68
1 is fixed on a front end 70a of a connector 70 fixed to the right rear portion of the base 2 in FIG. 1, and the circuit is connected to the connector pins 72 by soldering. The front end portion 70a of the connector 70 is formed slightly lower than other portions of the connector 70 in order to secure the height of the solder by soldering the lead portion 68a while suppressing the overall height. Reference numeral 74 denotes a fitting hole that penetrates the base 2.
A through hole 68a1 is provided at a position corresponding to the fitting hole 74 in the drawer 68a. Reference numeral 78 denotes 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 corresponding to a change in height from the bottom and the outer peripheral surface of the annular concave portion 6 to the second convex portion 58, and corresponds to the fitting hole 74. In the position, the downwardly fitting projection 8
0 is provided. The fitting projection 80 penetrates through the through hole 68a1 of the lead-out portion 68a and fits in the fitting hole 74, and the floating prevention member 78 is fixed to the base 2, so that the flexible circuit board 68 is pulled out. Of the portion 68a, the annular recess 6
At least the hard disk 42
Is prevented from floating from the base 2. This easily and reliably prevents disconnection of the conduction path of the lead-out portion 68a and hinders rotation of the rotor hub 22 and movement of the magnetic head 46. It should be noted that the vertical positional relationship in the description of the above embodiment is merely for convenience of explanation based on the drawings, and does not limit the actual use situation and the like. According to the recording medium drive of the present invention, the ring member is fitted to the stator core and the annular base of the stator core is fitted to the cylindrical portion of the base.
Filling adhesive can be filled into the surrounding space defined by the base, the annular base, the core teeth, and the ring member so as to cover the upper surfaces of the stator coil and the annular base, and solidified.
By providing a reinforcing portion in the middle of the cylindrical portion on which the pair of ball bearings are mounted, it is possible to prevent the ball bearing from being distorted due to a contraction force caused by curing of the filling adhesive. Also, as compared to the case where the fitting projection is formed integrally with the base, the processing of the base is easier,
Overall high production efficiency. The fitting projection of the ring member is fitted into the circumferential gap between the outer peripheral portions of the core teeth, and the base cylinder
The rigidity of the stator core is increased together with the rigidity of the ring member and the base by the fitting and fixing of the annular base of the stator core to the part and the integral fixing of at least the base, the stator core, the stator coil and the ring member by the filling adhesive. As a result, the natural frequency of the stator core is increased, and the occurrence of resonance is well prevented, so that the vibration is effectively suppressed, which greatly contributes to the improvement of the rotational accuracy, and is effective in increasing the recording density with respect to the recording medium. It is.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view showing a state where a cover of a disk chamber is removed. FIG. 2 is a sectional view taken along line II-PQS-II in FIG. FIG. 3 is a plan view of a ring member. FIG. 4 is a plan view of an essential part in a state where a stator to which a ring member is fitted is attached to a base. FIG. 5 is a sectional view taken along line VV in FIG. 4; FIG. 6 is an enlarged plan view of a lifting prevention member. [Reference Number] 2 Base 8 Cylindrical part 8a Small diameter part 10 Ring part 11 Ring member 12a Fitting convex part 12b Fitting convex part 14 Stator core 14a Ring base 14b Core teeth 14b1 Outer peripheral part 16 Stator coil 17 Filling adhesive 18 First Ball bearing 20 Second ball bearing

Claims (1)

(57) [Claims] 1. A radially outward direction from an annular base of a stator core.
Protruded topluralStator coil on core teethRespectively
Wound, the annular base of the stator core is provided on a base.
And a pair of ball bearings
A ring portion between the outer periphery of the stator core and the base.
Wood is attachedA recording medium drive device comprising:A reinforcing portion is provided in the middle of the cylindrical portion by diameter reduction processing, The ring member has a ring portion and an axial direction of the ring portion.
It protrudes and fits in the circumferential gap between the outer peripheral portions of the core teeth.
A plurality of fitting projections provided in
One of the axial portions of the portion contacts the bottom surface of the outer peripheral portion of the core tooth.
And the other axial side of the ring portion is in contact with the base.
Mounted as Filling adhesive is applied to the base, the annular base, the core teeth and the
The annular base and the sleeve in a space surrounded by the ring member.
Filled so as to cover the upper surface of the data coil, the base,
The stator core, the stator coil and the ring member are
Physically fixed Recording medium drive device characterized by the following:
Place.