JP3395913B2 - 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. In order to achieve the above object, a recording medium driving apparatus according to the present invention is characterized in that a plurality of projections provided on an annular end surface of a base of a cylindrical member are formed of a thin flat plate. The cylindrical member is erected on the base by being fitted to a plurality of fitting holes penetrating through the base, and the cylindrical member is erected on the base, and protrudes radially outward from the annular base of the stator core. A recording medium driving device in which a stator coil is wound around the cylindrical member, and an annular base of the stator core is fitted and fixed to the cylindrical member, wherein a fitting convex portion protruded in an axial direction from a ring portion of the ring member. Is fitted in the circumferential gap between the outer peripheral portions of the core teeth, 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 axial direction side of the ring portion contacts the base. The base, the annular base and the tubular member, A space filled with the teeth and the ring member is filled with a filling adhesive, and the base, the tubular member, the stator core, the stator coil, and the ring member are integrally fixed by the filling adhesive. [0008] An axially projecting projection is provided from a ring portion of a ring member in a circumferential gap between outer peripheral portions of core teeth of a stator core fitted and fixed to a tubular member erected on a base with an annular base. The fitted projections fit, and on the bottom surface of the outer periphery of the core teeth,
One side of the ring portion in the axial direction is in contact, and the other side of the ring portion in the axial direction is in contact with the base, so that the base, the annular base and the tubular member of the stator core, and the core teeth and the ring member surround the base. The filling adhesive can be easily filled and solidified in the space as it is. The annular base of the stator core is fitted and fixed to the tubular member erected on the base, and the fitting projection of the ring member fits in the circumferential gap between the outer peripheral portions of the core teeth of the stator core. The flat base, which itself has relatively low strength and rigidity, the cylindrical member fixed to the base at the base, the stator core, the stator coil, and the ring member are integrally fixed by the filling adhesive. The overall strength and stiffness are increased, thereby increasing their natural frequency, including the stator core. An embodiment of the present invention will be described with reference to the drawings. 1 to 6 show a hard disk drive as an embodiment of the present invention. FIG. 1 is a sectional view of a main part, FIG. 2 is a perspective view of a cylindrical member, and FIG. FIG. 4 is a plan view of a main part in a state where the stator to which the ring member is fitted is attached to the base, and FIG.
FIG. 6 is a front sectional view showing a state in which the stator fitted with the ring member is attached to the base, and FIG. 6 is a plan view. 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 fixed shaft 7 (made of brass steel) is suspended from the base 2 at a position near the center of the drive / read / write unit A1. The fixed shaft 7 has a base 2 with a reduced diameter portion 7a at the lower end.
Is fitted into a fitting hole 2a penetrating the base 2 and the reduced diameter portion 7a at the lower end and the base 2 are fixed by laser welding. For example, as shown in FIG.
Then, the fixed shaft 7 can be fixed to the base 2 by caulking with a caulking jig 9 or the like from the lower surface of the reduced diameter portion 7a at the lower end. Upper end reduced diameter portion 7b of fixed shaft 7
Are fitted and fixed to the lid 4. On the outer peripheral side of the fixed shaft 7, concentrically therewith,
A cylindrical member 8 made of a synthetic resin is erected on the base 2. The base of the tubular member 8 protrudes outward, and has three downward projections 8a at every 120-degree center angle on the lower annular surface of the base. After this downward projection 8a is fitted into the fitting hole 2b penetrating the base 2, it is fused to the base 2 by being melted using a laser beam or the like, whereby the cylindrical member 8 is attached to the base 2. Fixed. 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 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 annular base portion 14a is externally fitted and fixed to the cylindrical member 8 at the annular base portion 14a.
The lead portion 68a of the flexible circuit board 68 is
6 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. 6, a connector portion for external connection is provided (not shown). The ring portion 10, the outer peripheral portion 14b1, the fitting protrusions 12a and 12b, and the annular portion between the annular base portion 14a and the cylindrical member 8 are filled from each slot of the stator core 14 with the 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 member 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. An axial projection from the ring portion 10 of the ring member 11 is provided in the circumferential gap between the outer peripheral portions 14b1 of the core teeth 14b of the stator core 14 fitted and fixed to the cylindrical member 8 erected on the base 2. The fitting protrusions 12a and the upper protrusions 12b1 of the fitting protrusions 12b are fitted, and the core teeth 14
Since the upper surface of the ring portion 10 is in contact with the bottom surface of the outer peripheral portion 14b1 of b, and the lower surface of the ring portion 10 is in contact with the base 2,
The base 2, the annular base 14a and the cylindrical member 8, and the core teeth 1
4b and 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 member 8 are integrally formed on the base, there is no need to process the base. Therefore, it can be efficiently manufactured as a whole. In addition, it is possible to use a thin plate in which it is difficult to process the fitting convex portion, the annular portion, and the like.
Since the cylindrical member 8 and the ring member 11 are directly fixed to the base 2 and the bottom plate of the stator is omitted, it is highly effective in reducing the thickness of the entire apparatus. The annular base 14a of the stator core 14 is fitted and fixed to the cylindrical member 8 erected on the base 2, and the fitting projection 12a of the ring member 11 and the upper projection 12b1 of the fitting projection 12b are connected to the core. A flat base 2, which is fitted into the circumferential gap between the outer peripheral parts 14b1 of the teeth 14b and has relatively low strength and rigidity, a tubular member 8 fixed to the base 2 at the base, a stator core 14, and a stator coil Since the ring 16 and the ring member 11 are integrally fixed by the filling adhesive 17, the strength and rigidity of the whole are increased. The adhesive 17 is filled over the entire circumference of the stator core 14.
Is filled and solidified, so that the effect is great. 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 fixed shaft body 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 fixed shaft body 7. Annular overhang 22b
Has, in order from the top, a small-diameter portion 22b1, a large-diameter portion 22b2, and a small-diameter annular projection 22b3 protruding downward. The inner peripheral side of the annular protrusion 22b3 is formed in an annular groove 22b4 having a lower opening, into which the upper end of the tubular member 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 fitted and fixed to 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 slightly spaced from the outer peripheral surface of the fixed shaft body 7 in the radial direction. Are opposed to each other. Thereby, the first ball bearing 1
8 is prevented from scattering into the disk chamber 3 from above. The labyrinth sealing effect is obtained by the cylindrical portion 22a, the cylindrical member 8, and the annular groove portion 22b4 of the rotor hub 22, so that the fine lubricant 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 portion 38 formed between the holding annular plate 28 and the rotor magnet 30 and having a radially inward opening stores lubricant fine particles and the like from the second ball bearing 20, and is stored in the disk chamber 3. It has the effect of preventing scattering. 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, the base 2 and the cover 2 are protected in almost all areas except the movable range of the hard disk 23 and the arm 62 to protect the internal mechanism.
A reinforcing block 66 made of a synthetic resin is interposed between the cover 4 and the cover 4. The dimensions, number, material, shape, relative arrangement, and the like of the components in the above description of the embodiments are not limited to those described unless otherwise specified.
It is not intended to limit the scope of the present invention to them only, but is merely an illustrative example. The recording medium drive of the present invention is formed by fixing the tubular member to the base, fitting the ring member to the stator core, and fitting the annular base of the stator core to the tubular member. Further, the filling adhesive can be easily filled and solidified in the surrounding space defined by the base, the annular base and the cylindrical member of the stator core, and the core teeth and the ring member. Further, the base is flat, and it is not necessary to process the base unlike the case where the fitting projection and the annular portion corresponding to the cylindrical member are integrally formed on the base. Therefore, it can be efficiently manufactured as a whole. Further, the fitting projection of the ring member is fitted in the circumferential gap between the outer peripheral portions of the core teeth, the fitting and fixing of the annular base of the stator core to the cylindrical member erected on the base, and the filling adhesive. , The strength and rigidity of the entire base are increased, even though the base is flat, whereby the entire base including the stator core is fixed. , The occurrence of resonance is satisfactorily 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. Further, since the tubular member and the ring member are directly fixed to the base, the bottom plate of the stator is omitted, and the entire device is reduced in thickness. 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 perspective view of a tubular member. 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 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. 6 is a plan view of the device with the lid removed. FIG. 7 is a sectional view of a main part showing a fixed state of a fixed shaft body. [Description of References] 2 Base 2a Fitting hole 7 Fixed shaft 7a Lower end reduced diameter portion 8 Cylindrical member 11 Ring member 12a Fitting convex portion 12b Fitting convex portion 14 Stator core 14a Annular base 14b Core teeth 14b1 Outer peripheral portion 16 Stator Coil 17 Filling adhesive

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) G11B 19/20 H02K 29/00

Claims (1)

(57) [Claims 1] A plurality of projections formed on an annular end face of a base of a tubular member are fitted into a plurality of fitting holes penetrating a base made of a thin plate and are fitted to the base. By being fixed, the cylindrical member is erected on the base, a stator coil is wound around core teeth projecting radially outward from an annular base of the stator core, and the annular base of the stator core is A recording medium drive device fitted and fixed to a member, wherein a fitting protrusion protruding in an axial direction from a ring portion of a ring member fits in a circumferential gap between outer peripheral portions of the core teeth. 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 of the ring portion in the axial direction contacts the base. The base, the annular base and the tubular member, the core teeth, Filling adhesive fills the space surrounded by the ring member And
A recording medium drive, wherein a base, a tubular member, a stator core, a stator coil, and a ring member are integrally fixed by a filling adhesive.