JP3393611B2 - Recording medium drive - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording medium drive in which a spindle motor is provided integrally with 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 nonvolatile auxiliary storage device attached to them to be reduced in size, thickness and capacity. [0003] A so-called flash memory is incorporated in an IC memory card thinned to a thickness of about 5 mm, but satisfactory storage capacity has not been obtained. As one means for realizing a thin, large-capacity nonvolatile auxiliary storage device, it is conceivable to use a recording medium drive device provided with a spindle motor for driving a recording medium such as a hard disk. [0005] However, in order to increase the recording capacity while reducing the size and thickness of the IC memory card to the same level,
It is necessary to prevent the spindle motor from vibrating as much as possible and realize higher rotational accuracy, thereby increasing the recording density on the recording medium. 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 thickness and size of the entire device as much as possible.
It is an object of the present invention to provide a recording medium drive capable of preventing rotation of a spindle motor as much as possible, improving rotational accuracy, and increasing recording density on a recording medium to realize a large recording capacity. [0007] In order to achieve the above object, a recording medium driving device according to the present invention comprises a cylindrical portion and a circular portion.
A bottom provided to close the bottom of the tubular part and this bottom
A column that protrudes coaxially from the part in the same direction as the cylindrical part
Bottomed cylindrical portion, thin in its base periphery portion consisting of
A stator coil is wound around core teeth protruding radially outward from an annular base of the stator core, and is fitted and fixed coaxially in an engagement hole provided in a plate-shaped base. A recording medium drive device fitted and fixed to the cylindrical portion, wherein a fitting protrusion protruding in an axial direction from a ring portion of a ring member is provided in a circumferential gap between outer peripheral portions of core teeth. The ring is in contact with the bottom surface of the outer periphery of the core tooth on one side in the axial direction of the ring portion, and the other side in the axial direction on the ring portion is in contact with the base, and the base, the annular base, the core teeth, and the ring The space enclosed by the members is filled with a filling adhesive, and the base, the stator core, the stator coil, and the ring member are integrally fixed by the filling adhesive. The bottomed cylindrical portion has an outer peripheral portion at the base portion.
In the circumferential gap between the outer peripheral parts of the core teeth of the stator core in the stator core, which is fitted and fixed coaxially in the fitting hole provided in the base, and fitted and fixed to the cylindrical part of the bottomed cylindrical part with the annular base. A fitting protrusion protruded in the axial direction from the ring portion of the ring member is fitted, one axial side of the ring 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, so that the space surrounded by the base, the annular base of the stator core, the core teeth and the ring member can be easily filled with the filling adhesive as it is and solidified. . The annular base of the stator core is fitted and fixed to the cylindrical portion of the bottomed cylindrical portion which is coaxially fitted and fixed to the fitting hole provided in the base, and the fitting projection of the ring member is fixed to the stator core. Fits in the circumferential gap between the outer peripheral portions of the core teeth of itself, the plate base, the stator core, the stator coil and the ring member, which itself has relatively low strength and rigidity,
Since they are integrally fixed by the filling adhesive, their overall strength and rigidity are increased, and thus their natural frequencies including the stator core are increased. An embodiment of the present invention will be described with reference to the drawings. 1 to 5 relate to a hard disk drive as an embodiment of the present invention, in which FIG. 1 is a sectional view of a main part, FIG. 2 is a plan view of a ring member, and FIG.
FIG. 4 is a front cross-sectional view of a state in which the stator in which the ring member is fitted is attached to the base, FIG. 4 is a front cross-sectional view of a state in which the stator in which the ring member is fitted is attached to the base, and FIG. . Needless to say, the recording medium that can be targeted in the recording medium driving device of the present invention is not limited to a hard disk. This hard disk drive A has a thickness of 5
In order to make the same size as the IC memory card (TYPE 2) of mm, the drive / read / write unit A1 for rotating and driving the hard disk and reading / writing from / to the hard disk and the circuit unit A2 for operating them are the same as the conventional one. Instead of being arranged in a vertically superposed state, that is, in the vertical direction, they are arranged in a so-called horizontal direction in substantially the same plane. Reference numeral 2 denotes a 0.4 mm-thick flat plate-shaped base of forged stainless steel in the hard disk drive A. Reference numeral 4 denotes a cover of the apparatus, which is composed of a main plate 4a made of stainless steel and having a thickness of 0.25 mm and a reinforcing plate 4b. Base 2
5 has a horizontally long flat rectangular shape in FIG. 5, the disk drive / read / write unit A1 is located on the left side, and the circuit unit A2 is located on the right side. A fitting hole 2a is provided at a position near the center of the drive / read / write portion A1, and the bottomed cylindrical member B is
The base portion is coaxially fitted and fixed in the fitting hole 2a at the outer peripheral portion. The bottomed cylindrical member B has a columnar column 7 projecting coaxially from a disk-shaped bottom 6 in the same direction as the cylindrical portion 8. An annular projection 8 is provided on the lower part of the outer periphery of the cylindrical portion 8.
is provided, and the lower surface of the annular projection 8a abuts on the upper surface of the base 2 around the fitting hole 2a, thereby increasing the strength and rigidity of the fitting of the bottomed cylindrical member B into the fitting hole 2a. ing. The upper end reduced diameter portion 7 a of the column 7 is fitted and fixed to the lid 4. As shown in FIGS. 2 and 4, 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 arranged alternately except that the fitting projection 12a on the right side in FIG. 2 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 protrusions 12a and 12b and the outer surface 14b1 have the same height. 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 includes 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 is performed in correspondence with 2. The stator core 14 to which the ring member 11 and the flexible circuit board 68 are attached in this manner.
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 in a state in which the ring base 11a is externally fixed to the cylindrical portion 8 at the annular base portion 14a.
The lead portion 68a of the flexible circuit board 68 is
5 is pulled out to the right in FIG.
It is connected to the circuit section A2 provided above. Circuit part A2
At the right end in FIG. 5, a connector portion for external connection is provided (not shown). The annular portion between the ring portion 10, the outer peripheral portion 14b1, the fitting projections 12a and 12b, and the annular base portion 14a and the cylindrical portion 8 is filled from each slot of the stator core 14 with a filling adhesive 17 (adhesive and filler). It has both functions of an agent.
In terms of heat resistance, a thermosetting resin is preferable. For example, 10
What is cured by heating to about 0 ° C. ) Is filled,
Base 2, cylindrical portion 8, annular base 14a, core teeth 14b,
The ring member 11, the stator coil 16, and the annular portion 68b of the flexible circuit board 68 are integrally fixed by solidifying the filling adhesive 17. 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. The stator core 14 fitted and fixed to the cylindrical portion 8 of the cylindrical member B having a bottom has a circumferential gap between the outer peripheral portions 14b1 of the core teeth 14b and protrudes from the ring portion 10 of the ring member 11 in the axial direction. The fitting protrusion 12a and the upper protrusion 12b1 of the fitting protrusion 12b fit together, and the core teeth 1
Since the upper surface of the ring portion 10 is in contact with the bottom surface of the outer peripheral portion 14b1 of the outer peripheral portion 4b, and the lower surface of the ring portion 10 is in contact with the base 2, the base 2, the annular base portion 14a and the cylindrical portion 8, the core teeth 14b and In the space surrounded by the ring member 11, the filling adhesive 17 can be easily filled and solidified as it is. Since the base 2 is flat,
Unlike the case where the fitting projections 12a and 12b and the annular portion corresponding to the cylindrical portion 8 are integrally formed on the base, it is not necessary to process the base. Therefore, it can be efficiently manufactured as a whole. It is also possible to use a thin plate in which it is difficult to process the fitting convex portion, the annular portion, and the like. Further, the bottomed cylindrical member B having the cylindrical portion 8 is provided with the fitting hole 2.
Since the ring member 11 is directly fixed to the base 2 and the bottom plate of the stator is omitted, the effect is high in reducing the thickness of the entire apparatus. The annular base 14a of the stator core 14 is fitted and fixed to the cylindrical portion 8 of the bottomed cylindrical member B fitted and fixed in the fitting hole 2a of the base 2, and the fitting projection 12a of the ring member 11 is fitted. The upper protrusion 12b1 of the fitting protrusion 12b is fitted in the circumferential gap between the outer peripheral portions 14b1 of the core teeth 14b, and the plate-like base 2 itself having relatively low strength and rigidity is formed on the base 2 at the base. Cylindrical portion 8 of fixed bottomed cylindrical member B, stator core 14, stator coil 1
Since the ring 6 and the ring member 11 are integrally fixed by the filling adhesive 17, the overall strength and rigidity thereof are increased. Since the filling adhesive 17 is filled and solidified over the entire circumference of the stator core 14, the effect is large. As a result, the natural frequencies of all of them including the stator core 14 are also increased, and the occurrence of resonance is favorably prevented. Therefore, the vibration is effectively suppressed, which greatly contributes to the improvement of rotation accuracy. This is effective in increasing the recording density on the medium. 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, the occurrence of eddy current loss and hysteresis loss during motor driving 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 inner rings of the first ball bearing 18 and the second ball bearing 20 are fixed to the outer peripheral surface of the column 7 with an adhesive. Reference numeral 22 denotes a rotor hub. Rotor hub 22
Consists of a cylindrical portion 22a and an annular projecting portion 22b provided on the outer periphery of the upper portion thereof. The outer rings of the first ball bearing 18 and the second ball bearing 20 are fixed to the inner peripheral surface of the cylindrical portion 22a by an adhesive. I have. Thereby, the rotor hub 22 is rotatably supported by the support column 7. The annular overhang 22b
In order from the top, a small-diameter portion 22b1, a large-diameter portion 22b2, and a small-diameter annular projection 22b3 protruding downward are provided. The inner peripheral side of the annular protrusion 22b3 is an annular groove 22b having a downward opening.
4 in which the upper end of the cylindrical portion 8 is inserted. A 1.3-inch hard disk 23 is externally fitted to the small-diameter portion 22b1, and its inner peripheral portion is
4 and the large-diameter portion 22b2. The clamper 24 is screwed to the inner peripheral portion of the annular projecting portion 22b. Under the large diameter portion 22b2, an annular protrusion 22b
3, the inner peripheral portion of the holding annular plate 28 is fixed. A hanging portion 28a holding an annular rotor magnet 30 inside is provided on an outer peripheral portion of the holding annular plate 28.
And the rotor magnet 30 and the stator core 14
They are opposed by a radial gap. Holding annular plate 2
Numeral 8 is made of a soft magnetic material, and the rotor magnet 3
Zero yoke and magnetic shield plate. An annular seal plate 25 is fixedly fitted in the inner peripheral portion of the upper end of the cylindrical portion 22a of the rotor hub 22, and the inner peripheral portion of the seal plate 25 is separated from the outer peripheral surface of the column 7 by a slight radial gap. Are facing each other. This prevents lubricant particles and the like from the first ball bearings 18 from scattering into the disk chamber 3 from above. The labyrinth sealing effect is obtained by the cylindrical portion 22a, the cylindrical portion 8, and the annular groove portion 22b4 of the rotor hub 22, and lubricant fine particles and the like from the second ball bearing 20 are transferred between the base 2 and the hanging portion 28a. Is prevented from being scattered into the disk chamber 3. Further, an annular groove formed in a radially inward opening formed between the holding annular plate 28 and the rotor magnet 30 stores lubricant particles and the like from the second ball bearing 20 and scatters into the disk chamber 3. It has the effect of preventing A gap is provided between the lower surface of the hard disk 23 and the upper surface of the holding annular plate 28 so that the lower one of the magnetic heads 46 disposed on the upper and lower surfaces of the hard disk 23 can enter and exit. The main plate 4a of the lid 4 is
Is reinforced by the reinforcing plate 4b except for the movable range of. Reference numeral 60 denotes a pivot assembly fixed to the base 2, and an arm 62 for holding a magnetic head 46 and a voice coil (not shown) at the distal end and the base, respectively, is rotatable with respect to the base 2. It is to support. Numeral 64 is a yoke of a voice coil motor for rotating the arm 62 to position the magnetic head 46. 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. Further, since the base 2 and the lid 4 are both thin plates, a synthetic resin reinforcement is provided between the base 2 and the lid 4 in almost the entire area excluding the movable range of the arm 62 to protect the internal mechanism. A block 66 is interposed. FIG. 6 is a sectional view of a main part of a hard disk drive according to another embodiment of the present invention. In this embodiment, the periphery of the fitting hole 102a of the base 102 is formed in the annular rising part 102b, so that the fitting strength and rigidity of the bottomed cylindrical member C are increased. The cylindrical portion 108 of the bottomed cylindrical member C does not have an annular protrusion unlike the above-described embodiment, and the filling adhesive 17 is hardly fixed to the cylindrical portion 108. FIG. 7 is a sectional view of a main part of a hard disk drive according to still another embodiment of the present invention. Also in this embodiment, the periphery of the fitting hole 102a of the base 102 is formed in the annular rising part 102b, so that the fitting strength and rigidity of the bottomed cylindrical portion D are increased. This bottomed cylindrical part D
Is formed by fixing a base of a cylindrical portion 208 to an outer peripheral portion of a disk-shaped bottom portion 206 having a column 207 in a central axial direction, and the cylindrical portion 208 does not have an annular protrusion. The filling adhesive 17 hardly adheres to the cylindrical portion 208. The rotor hub 222 has a central cylindrical shaft portion 222.
a between the outer peripheral portion 222b and the outer peripheral portion 222b.
c is formed. The upper and lower ball bearings are provided between the outer peripheral portion of the central cylindrical shaft portion 222a and the inner peripheral portion of the cylindrical portion 208 in a state where the column 207 is inserted through the central cylindrical shaft portion 222a with a slight radial gap therebetween. With the 218 and 220 interposed, the rotor hub 222 is rotatably supported. The upper portions of the upper ball bearing 218 and the cylindrical portion 208 are substantially housed in the annular groove 222c. In addition, the upper end reduced diameter portion 207a of the column 207 is
Is fitted and fixed. In this embodiment, since the cover 4 is supported by the support pillars 207 in a so-called shaft rotation type, the cover 4 and the rotor hub 222 are formed although the rigidity of the cover 4 is relatively low. Is prevented from coming into contact with. In addition, the bottom 206 and the support 207 and the central cylindrical shaft 2
The effect of labyrinth seal is exhibited by 22a,
Lubricant particles and the like from the lower ball bearing 220 are
Scattering from the upper opening of 22a is effectively prevented. The scope of the present invention is limited to only the dimensions, the number, the material, the shape, the relative arrangement, and the like of the components in the description of the above embodiments, unless otherwise specified. It is not intended to be a mere explanation, but merely an explanation example. According to the recording medium driving apparatus of the present invention, the bottomed cylindrical portion is fitted and fixed to the fitting hole of the base, the ring member is fitted to the stator core, and the bottomed cylindrical portion is formed. By filling the filling adhesive easily in the surrounding space formed by fitting the base of the stator core to the cylindrical portion, the base of the stator core, the base of the stator core, and the core teeth and the ring member as it is. Can be solidified. Further, the base is flat, and it is necessary to process the base as in the case of integrally forming the fitting projection of the ring member and the annular portion corresponding to the cylindrical portion of the bottomed cylindrical portion on the base. Absent. Therefore, it can be efficiently manufactured as a whole. Further, the fitting convex portion of the ring member is fitted in the circumferential gap between the outer peripheral portions of the core teeth, and the bottomed cylindrical shape is fitted and fixed coaxially in the fitting hole provided in the base. The base, stator core, stator coil and ring member are integrally fixed by the filling adhesive to the annular base of the stator core with respect to the cylindrical part of the part, even though the base is flat, Strength and rigidity are increased, thereby increasing the natural frequency of the entire body including the stator core, and the occurrence of resonance is effectively prevented, and the vibration is effectively suppressed. Therefore, it is possible to improve the rotation accuracy and increase the recording density on the recording medium. Further, since the base is flat, a thin plate in which it is difficult to process the fitting convex portion, the annular portion, and the like can be used, which is highly effective in reducing the thickness of the entire device. In addition, since the bottomed cylindrical portion is fitted and fixed in the fitting hole of the base and the ring member is directly fixed to the base, the bottom plate of the stator is omitted and the entire device is made thinner. Therefore, for example, the thickness of the device can be set to about 5 mm like the IC memory card, and the recording capacity can be greatly increased.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an enlarged sectional view of a device. FIG. 2 is a plan view of a ring member. FIG. 3 is a plan view of a main part in a state where a stator fitted with a ring member is mounted on a base. FIG. 4 is a cross-sectional view of a main part of a front part in a state where a stator fitted with a ring member is mounted on a base. FIG. 5 is a plan view of the device with the lid removed. FIG. 6 is a sectional view of a main part of a hard disk drive according to another embodiment. FIG. 7 is a sectional view of a main part of a hard disk drive according to still another embodiment. [Description of References] 2 Base 2a Fitting hole B Bottomed cylindrical member 6 Bottom 7 Column 8 Cylindrical portion 11 Ring member 12a Fitting convex portion 12b Fitting convex portion 14 Stator core 14a Ring base 14b Core teeth 14b1 Outer peripheral portion 16 Stator coil 17 Filling adhesive

Claims (1)

(57) [Claims 1] A cylindrical portion and a bottom surface of the cylindrical portion are closed.
So that the bottom provided is the same as the cylindrical part from this bottom
A cylindrical part having a bottom, which is composed of a column protruding coaxially in the direction, is coaxially fitted and fixed to a fitting hole provided in a thin plate-shaped base at an outer peripheral portion of the base, and an annular base of the stator core is provided. A recording medium drive device comprising a stator coil wound around core teeth projecting radially outward from the cylindrical member, and an annular base of the stator core fitted and fixed to the cylindrical portion; A fitting projection protruding in the axial direction is fitted into the circumferential gap between the outer peripheral portions of the core teeth, and one side in the axial direction of the ring portion contacts the bottom surface of the outer peripheral portion of the core teeth. The other side in the axial direction is in contact with the base, and a space surrounded by the base, the annular base, the core teeth, and the ring member is filled with a filling adhesive, and the base, the stator core, the stator coil, and the ring member are filled. But the filling adhesive A recording medium drive device, which is more integrally fixed.