JP2004288309A - Disk device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a disk device in which a device can be made extremely small/thin, and high performance and high reliability are attained. <P>SOLUTION: The disk device is composed of a rotating shaft which is held to be rotatable by the bearing fixed to a base plate part, a spindle hub which is fixed to the rotating shaft, a disk whose inner peripheral part is supported by the spindle hub, a disk clamping means which fixes the disk to the spindle hub and a spindle motor which performs the rotation drive of the disk. The disk clamping means has a first clamping ring and a second clamping ring which hold the inner peripheral part of the disk with the spindle hub and a plurality of screws which are screwed to the hub through screw threading holes of the second clamping ring and a ring shaped leaf spring which is interposed between the first and second clamping rings and which transmits the fastening force to be applied to the second clamping ring to the first clamping ring. The disk clamping means is characterized by being arranged between the base plate part and the uppermost surface of the spindle hub. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a disk device, such as a hard disk device, for fixing a disk to a rotationally driven spindle hub, and more particularly to a disk clamp technique suitable for being applied to a very small and ultra-thin disk device. It is.
[0002]
[Prior art]
The hard disk device includes a magnetic disk (hard disk) as a magnetic recording medium, a spindle motor for rotating and driving the magnetic disk, a magnetic head for performing recording / reproducing while floating with a small gap with respect to the surface of the magnetic disk, An actuator arm for movably supporting the head with respect to the magnetic disk, and a voice coil motor for driving the actuator arm to move the magnetic head to a desired track position on the magnetic disk for positioning.
[0003]
In recent years, in order to improve the recording density of a hard disk drive, a method of reducing the bit width of a track by improving track positioning accuracy of a head, or a method of reducing a bit length in a head traveling direction by reducing a flying height of a head. But it has been pushed forward. In either case, the method of fixing the magnetic disk is to secure the positional accuracy with respect to the rotating shaft, and to secure a sufficient fixing load (clamping force) to withstand an external impact load. It is necessary to secure the head positioning accuracy by minimizing the amount of deformation applied.
[0004]
2. Description of the Related Art Conventionally, as a method of suppressing undulation and deformation generated in a magnetic disk and securing assembly accuracy and a clamping force, a method of increasing a clamping force of a magnetic disk by using a compressive force generated in a clamper (Patent Document 1), A method of reducing disk deformation by providing a ring-shaped elastic body between a magnetic disk and a hub (Patent Document 2), and a method of disposing a top spacer ring between a magnetic disk and a clamp ring to suppress disk deformation (Patent Document 3) is known.
[0005]
[Patent Document 1]
JP-A-11-96636 [0006]
[Patent Document 2]
JP 2001-291301 A
[Patent Document 3]
JP-A-7-296476
[Problems to be solved by the invention]
In recent years, there has been a demand for ultra-compact and ultra-thin hard disk drives. Among devices using a 1.8-inch or 1.0-inch ultra-small magnetic disk, a hard disk device with a total thickness of 5 mm is currently being commercialized. As the thickness of the spindle motor further decreases in the future, it is necessary to further reduce the thickness of the spindle motor. However, in order to reduce the thickness of the motor, it is necessary to reduce the thickness of the shaft and bearings. However, as the shafts and bearings become thinner, the rotational accuracy deteriorates, that is, the amount of disk vibration increases.Therefore, it is necessary to design the shaft and bearings to maximize the thickness of the hard disk drive. It is becoming.
[0009]
By the way, the above-mentioned conventional technology has the following problems.
[0010]
In the methods disclosed in Patent Documents 1 and 2, a screw for fixing the disk clamp is disposed at the center of the upper surface of the spindle hub. The thinning design of the disk is hindered.
[0011]
Further, in the method disclosed in Patent Document 3, since the screw is not disposed at the center of the upper surface of the spindle hub, a design in which the disk clamp and the screw do not protrude from the upper surface of the spindle hub is possible. However, since the clamping force locally increases near the position where the disk clamp screw is attached, the disk undulates. Therefore, stable recording / reproduction of the magnetic head floating on the disk surface with a minute gap is hindered. Also, when tightening the screw, the disc clamp contacts the disc locally, so the load concentrates on the contact point, the disc clamp and the disc slide, and fine dust in the form of powder from the surfaces of each other. appear. When the dust generated in this way comes into close contact with the disk surface, the magnetic head comes into contact with the dust and the head is destroyed, so that the magnetic disk device cannot be repaired.
[0012]
As described above, the conventional disk clamp structure has a factor that hinders thinning, high performance, and high reliability of the magnetic disk device.
[0013]
Here, the technical problem (difficulty) of the disk clamp in the ultra-small and ultra-thin disk device will be described. For example, a hard disk drive using a magnetic disk having an outer diameter of 1 inch and having the same external dimensions (43 mm × 36 mm × 3.3 mm) as a compact flash (registered trademark) memory type I is taken as an example. When a shaft and a bearing with a small diameter are used, the inner diameter of the magnetic disk can be reduced to increase the recording capacity. However, when a shaft and a bearing with a small diameter are used in a casing having a thickness of 3.3 mm, the rotation of the magnetic disk is reduced. Accuracy deteriorates significantly. For this reason, in order to keep the rotation accuracy of the magnetic disk favorable in a casing having a thickness of 3.3 mm, it is necessary to secure the diameters of the shaft and the bearing to some extent. In the current technology, the outer diameter (diameter) of the bearing is required. Needs to be 5 mm or more. Also, if the magnetic disk is directly fixed to the shaft rotatably held by the bearing with an adhesive, the inner diameter of the magnetic disk can be reduced as much as possible. ) Greatly deteriorates the reliability, and it is a reality that it is desired to avoid using an adhesive in a disk device such as a hard disk device. Therefore, it is required to fix the magnetic disk to the spindle hub fixed to the shaft by using a disk clamping means without using an adhesive, but in order to secure a sufficient storage capacity with a magnetic disk having an outer diameter of 1 inch. Is required to have an inner diameter (diameter of a center hole) of 10 mm or less, and due to the restriction from the disk inner diameter and the restriction from the outer diameter of the bearing, the arrangement space of the disk clamping means is limited to a small one. You. In this small arrangement space, securing a sufficient fixed load (clamping force) capable of resisting an external impact load and minimizing the amount of deformation applied to the magnetic disk are disclosed in the above-mentioned patent documents. It is difficult to achieve with the technique described in (1).
[0014]
SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and an object of the present invention is to provide a microminiature / ultra-thin disk device in which a rotary shaft is required to be arranged in a narrow space while ensuring the rotational accuracy of the rotating shaft. The disk clamp means provided ensures a sufficient fixed load (clamping force) that can withstand an external impact load and suppresses the amount of deformation applied to the disk as much as possible. It is an object of the present invention to simultaneously achieve ultra-small and ultra-thin disk devices, high performance, and high reliability.
[0015]
[Means for Solving the Problems]
In order to achieve the above object, in a typical invention according to the present application,
A bearing fixed to a bottom plate part forming a part of the casing, a rotating shaft rotatably held by the bearing, a spindle hub fixed to the rotating shaft, and a A disk device comprising a disk carrying a peripheral portion, disk clamping means for fixing the disk to the spindle hub, and a spindle motor for driving the disk to rotate.
The disk clamping means includes: a first clamp ring for clamping an inner peripheral portion of the disk with a flange portion of the spindle hub; a second clamp ring having a plurality of screw insertion holes formed therein; A plurality of screws screwed into the spindle hub through screw insertion holes of a clamp ring, and the screw interposed between the first clamp ring and the second clamp ring and added to the second clamp ring A ring-shaped leaf spring for transmitting the tightening force to the first clamp ring,
A configuration in which the first clamp ring, the second clamp ring, the ring-shaped leaf spring, and the plurality of screws are arranged between the bottom plate portion and the uppermost surface of the spindle hub. Take.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0017]
FIG. 1 is a top view of a hard disk drive according to an embodiment of the present invention (hereinafter, referred to as the present embodiment) in which an upper cover of a casing upper surface is removed and a part is cut away. FIG. 2 is a cross-sectional view of a main part taken along a plane passing through the disk rotation center axis 22 of FIG.
[0018]
The hard disk drive according to the present embodiment includes a magnetic disk 21 having an outer diameter of 1 inch, a component for rotationally driving the magnetic disk 21, and a magnetic head in a thin box-shaped casing having six surfaces (upper and lower surfaces and four side surfaces) closed. An actuator arm 11 that movably supports the magnetic disk 12 (FIG. 2) with respect to the magnetic disk 21; and a voice coil motor that drives the actuator arm 11 to move the magnetic head 12 to a desired track position on the magnetic disk 21 for positioning. 13 are arranged. The casing includes a base 1 having a bottom plate 1a, and side plates 1b forming four sides rising from the bottom plate 1a, a connector 3 inserted into a part of the side plate 1b, and A predetermined closed space is formed by the cover 2 (FIG. 2), and the outer dimensions of this casing are the same size (43 mm × 36 mm × 3.3 mm) as the compact flash (registered trademark) memory type I. Has become.
[0019]
A magnetic head 12 for recording / reproducing magnetic information is mounted on the tip of a pair of actuator arms 11 arranged on the front and back of the magnetic disk 21. The actuator arm 11 is turned around an arm rotation center axis 14 by a voice coil motor 13 composed of a permanent magnet 13a and a coil 13b, thereby moving the magnetic head 12 on the rotating magnetic disk 21. Seeks while floating, and performs recording / reproduction of magnetic information.
[0020]
In FIG. 2, 23 is a bearing, 24 is a rotating shaft, 25 is a spindle hub, 26 is a first clamp ring, 27 is a ring-shaped leaf spring, 28 is a second clamp ring, and 29 is a screw. According to the present invention, a disk clamping means for fixing the magnetic disk 21 to the spindle hub 25 by the first clamp ring 26, the ring-shaped leaf spring 27, the second clamp ring 28, and the plurality of screws 29 is provided. It is configured. Reference numeral 30 denotes a rotor magnet of a spindle motor formed of a ring-shaped permanent magnet fixed to the first clamp ring 26, and 31 denotes a stator coil of the spindle motor formed on the printed circuit board 32, and the rotor magnet 30 and the stator The coils 31 are arranged at substantially the same height, and the two 30 and 31 face each other with a predetermined clearance.
[0021]
The lower portion of the bearing 23 is fixed to a through hole formed in the bottom plate 1a of the base 1 by strong fitting, and the rotating shaft 24 is rotatably held by the bearing 23. On the upper side of 24, a spindle hub 25 is fixed by strong fitting. The bearing 23 has an outer diameter (diameter) of 5 mm or more. In the present embodiment, the outer diameter of the bearing 23 is about 5 mm. In this embodiment, a fluid bearing having a fluid interposed on the bearing surface is employed as the bearing 23. Thus, the rotation accuracy of the rotation shaft 24 (the rotation accuracy of the magnetic disk 21) can be favorably maintained in the casing having a thickness of 3.3 mm. The uppermost surface of the rotating shaft 24 and the uppermost surface of the spindle hub 25 are flush with each other, and the upper cover 2 and the uppermost surface of the rotating shaft 24 and the uppermost surface of the spindle hub 25 have another member interposed therebetween. Instead, they face each other with a small clearance, and the thickness of the fitting portion of the spindle hub 25 to the rotating shaft 24 is formed as thin as the strength allows. Therefore, in the casing having a thickness of 3.3 mm, the supported portion of the rotating shaft 24 with respect to the bearing 23 can be made as large as possible, thereby also improving the rotating accuracy of the rotating shaft 24 (the rotating accuracy of the magnetic disk 21). Can be maintained.
[0022]
The spindle hub 25 is made of stainless steel such as 304 series stainless steel and substantially covers the bearing 23, and the maximum diameter thereof is set slightly larger than the inner diameter of the magnetic disk 21. The lower part of the spindle hub 25 has a convex disk support for supporting a magnetic disk 21 having an inner diameter (diameter of a center hole) of 10 mm or less (in this embodiment, a magnetic disk 21 having an inner diameter of about 10 mm). The magnetic disk 21 is supported by the disk holding flange 25a and is inserted into the disk insertion portion 25b.
[0023]
Above the disk insertion portion 25b of the spindle hub 25, there is provided a first clamp ring fitting portion 25c having a diameter smaller than the inner diameter of the magnetic disk 21, into which the inner circumference of the first clamp ring 26 fits. The first clamp ring 26 is fitted to the first clamp ring fitting portion 25c. The first clamp ring 26 is formed of 430 stainless steel to which the rotor magnet 30 can be attracted (fixed) by magnetic force. The rotor clamp 30 is attached to the magnet holding portion 26a provided on the first clamp ring 26 by magnetic force. It is fixed.
[0024]
A second clamp ring fitting smaller in diameter than the first clamp ring fitting part 25c, in which the inner periphery of the second clamp ring 28 fits above the first clamp ring fitting part 25c of the spindle hub 25. The second clamp ring 28 is fitted to the second clamp ring fitting portion 25d. The second clamp ring 28 is formed of stainless steel such as 304 series stainless steel, and a material having a high Young's modulus is selected. The second clamp ring 28 is provided with a plurality of screw insertion holes through which a plurality of screws 29 are inserted, and has a high rigidity portion 28a held between the screw head of the screw 29 and the spindle hub 25; A spring material pressing portion 28b which is thinner than the high rigidity portion 25a and presses the ring-shaped leaf spring 27 is provided.
[0025]
The second clamp ring 28 is fixed to the spindle hub 25 by a plurality of screws 29 screwed into screw holes formed on the upper surface side of the spindle hub 25. A ring-shaped leaf spring 27 made of stainless steel for a spring is interposed between the second clamp ring 28 and the first clamp ring 26, and the ring-shaped leaf spring 27 is The first clamp ring 26 comes into contact with the lower surface of the spring material pressing portion 28 b of the ring 28 and also comes into contact with the top of the first clamp ring 26. Then, the ring-shaped leaf spring 27 transmits the tightening force of the screw 29 applied to the second clamp ring 28 to the first clamp ring 26, whereby the first clamp ring 26 is moved by the predetermined clamp force to the magnetic disk 21. Is fixed to the spindle hub 25. Since the screw 29 is tightened in a narrow arrangement space, a screw having a screw diameter of 0.8 mm or less is selected (in the present embodiment, the screw diameter is 0.8 mm), and the material is stainless steel. ing.
[0026]
As described above, in the present embodiment, the disk clamping means is entirely made of stainless steel, so that the coefficient of thermal expansion is substantially the same for the entire disk clamping means, and a good clamping state is obtained even if there is a temperature change. Can be maintained.
[0027]
In the present embodiment, the magnetic disk 21 is fixed (disk clamp) as follows.
[0028]
(1) The magnetic disk 21 is fitted into the disk insertion portion 25b of the spindle hub 25 in a state where the bearing 23, the rotating shaft 24, and the spindle hub 25 are incorporated in the bottom plate portion 1a of the base 1, and the magnetic disk 21 is The spindle hub 25 is supported on the disk supporting flange 25a.
[0029]
(2) The first clamp ring 26 to which the rotor magnet 30 has been previously attracted and fixed is fitted into the first clamp ring fitting portion 25c of the spindle hub 25, and the projection on the lower surface of the first clamp ring 26 is The magnetic disk 21 is brought into contact with the upper surface of the innermost peripheral portion.
[0030]
(3) The ring-shaped leaf spring 27 is inserted into the upper part of the spindle hub 25, and the outer peripheral side of the ring-shaped leaf spring 27 is brought into contact with the top of the first clamp ring 26.
[0031]
(4) The second clamp ring 28 is fitted into the second clamp ring fitting portion 25d of the spindle hub 25, and the lower surface of the high rigid portion 28a of the second clamp ring 28 contacts the upper surface of the spindle hub 25, The lower surface of the spring material pressing portion 28 b of the second clamp ring 28 is brought into contact with the inner peripheral side of the ring-shaped leaf spring 27.
[0032]
(5) The screw 29 is screwed into the screw hole of the spindle hub 25 through the screw insertion hole of the second clamp ring 28 and the screw 29 is tightened, so that the lower surface of the high-rigidity portion 28a of the second clamp ring 28 To the upper surface of the spindle hub 25. At this time, the ring-shaped leaf spring 27 pressed by the spring material pressing portion 28b of the second clamp ring 28 is elastically deformed, and the spring load is applied to the magnetic disk 21 through the first clamp ring 26. As a result, the magnetic disk 21 is fixed to the spindle hub 25 with a predetermined clamping force.
[0033]
In the present embodiment, as is apparent from the drawing, the first clamp ring 26, the ring-shaped leaf spring 27, the second clamp ring 28, and the tightening screw 29, which are components for fixing the magnetic disk 21, are provided. , Is disposed between the bottom plate 1a of the base 1 and the upper surfaces of the spindle hub 25 and the rotating shaft. Thus, as described above, the maximum size of the rotating shaft 24 and the bearing 23 in the thickness direction can be secured in the thickness of the entire hard disk device of 3.3 mm, and the bearing which is a fluid bearing is used. Since the outer diameter of 23 is about 5 mm, the rotation accuracy of the rotating shaft 24 (magnetic disk 21) can be improved. Further, a disk clamping means using a spring and a screw for tightening can be realized in a restricted narrow space between the outer diameter of the bearing 23 of about 5 mm and the inner diameter of the magnetic disk of about 10 mm. Furthermore, a ring-shaped rotor magnet 30 which is a component of the spindle motor is fixed to the first clamp ring 30, and a stator coil 31 made of a print coil which is a component of the spindle motor is arranged outside the rotor magnet 30. We are trying to establish. Accordingly, the thickness of the clamp ring (the first clamp ring 26 and the second clamp ring 28) is ensured, and the undulation of the clamp ring is minimized, and the rotor magnet 30 and the stator are placed in the dead space outside the clamp ring. The coil 31 can be arranged. As a result, in the present embodiment, it is possible to simultaneously improve the vibration characteristics of the motor and reduce the waviness of the disk while realizing a thin hard disk device.
[0034]
The effect of the disk clamp structure according to the present embodiment will be described with reference to FIGS. FIG. 3 shows a main part on the right side of the embodiment shown in FIG. FIG. 4 is a diagram illustrating a main part when the ring-shaped leaf spring 27 of the present embodiment and the second clamp ring 28 are integrated for comparison with the present embodiment.
[0035]
In FIG. 4, the same components as those of the above-described embodiment are denoted by the same reference numerals. In FIG. 4, reference numeral 41 denotes a spring / clamp ring, which has a plurality of screw insertion holes through which a plurality of screws 29 are inserted, and a pinched portion which is pinched between a screw head of the screw 29 and the spindle hub 25. 41a, and a ring-shaped spring portion 41b formed outside the held portion 41a. 4, the tightening force of the screw 29 is transmitted to the first clamp ring 26 by the ring-shaped spring portion 41b of the spring / clamp ring 45, and the magnetic disk 21 is fixed by the first clamp ring 26.
[0036]
FIG. 5 is a graph in which the horizontal axis represents the displacement of the tightening screw 29 and the vertical axis represents the clamping force applied to the magnetic disk 21 in the configurations of FIGS. In the graph, a straight line A corresponds to the embodiment of FIG. 3, and a straight line B corresponds to the configuration example of FIG.
[0037]
The target clamping force P is P = Fc × M ÷, where the target Fc of impact resistance acceleration applied to the magnetic disk 21 is 2000 G, the disk weight M is 0.5 g, and the static friction coefficient μ is 0.1 (worst value). μ = 10 kgf.
[0038]
As is clear from the straight line A in FIG. 5, in the present embodiment in FIG. 3, the displacement of the screw 29 required to generate the clamping force of 10 kgf is about 100 μm. On the other hand, in the configuration example of FIG. 4, since the flexibility of the ring-shaped spring portion 41b is not sufficient, even if the amount of displacement of the screw 29 is small, the generated spring load increases as shown by the straight line B in FIG. As is clear from the straight line B in FIG. 5, in the configuration example in FIG. 4, the displacement of the screw 29 required to generate the clamping force of 10 kgf is about 5 μm.
[0039]
Generally, the pitch of the thread is about 100 μm to 200 μm. In the configuration example of FIG. 4, in order to generate the required clamping force of 10 kgf, the screw 29 must be displaced by 5 μm. It is difficult to control by rotation. In addition, in the configuration example of FIG. 4, when a displacement of 5 μm or more is applied, the internal stress sharply increases and exceeds the elastic deformation region of stainless steel used as a material of the spring and clamp ring 45. As a result, plastic deformation and cracks occur, which results in an area where designing of the clamping force is impossible (shown by a dotted line in FIG. 5). For the above reasons, it is difficult to obtain a desired clamping force with the configuration example of FIG.
[0040]
On the other hand, in the present embodiment of FIG. 3, a ring-shaped leaf spring 27 is interposed between the first clamp ring 26 and the second clamp ring 28, and the ring-shaped leaf spring 27 having flexibility is provided. Since the elastic deformation amount is large, a highly feasible clamping force design becomes possible.
[0041]
The spring / clamp ring 45 of FIG. 4 requires additional processing by grinding a part of the spring / clamp ring 45 to a thickness of about 100 μm in order to exhibit spring properties. Is an issue. On the other hand, in the embodiment of FIG. 3, the number of components is increased by one, but a special processing technique is not required for manufacturing individual components, and a desired clamping force can be generated at low cost.
[0042]
Further, in the configuration example of FIG. 4, since the tightening load locally increases near the position where the screw 29 is screwed, the entire ring-shaped spring portion 41 b of the spring and clamp ring 45 undulates. For this reason, the ring-shaped spring portion 41b and the first clamp ring 26 are locally in contact with each other, the load is concentrated on the contact portion, and dust is generated due to sliding of each other, and the magnetic head cannot contact with the dust for repair. There is a concern that a serious failure may occur. On the other hand, in the present embodiment of FIG. 3, the second clamp ring 28 itself that receives the tightening load of the screw 29 does not need to have a spring property, and therefore has a high rigidity having the high rigidity portion 28a as described above. It can be designed as a structure that is not easily deformed, and a material having a high Young's modulus can be selected. Therefore, the undulation due to the distribution of the tightening load of the screw 29 can be reduced as much as possible, and the undulations of the ring-shaped leaf spring 27 and the first clamp ring 26 can be reduced as much as possible. Therefore, undulations generated on the magnetic disk 21 can be reduced as much as possible, and stable recording / reproduction of the magnetic head 12 floating on the surface with a minute gap can be ensured.
[0043]
In the above-described embodiment, the hard disk device is taken as an example. However, the present invention is applicable to an optical disk device and a magneto-optical disk as long as the disk device fixes the disk to a spindle hub that is driven to rotate. is there.
[0044]
【The invention's effect】
As described above, according to the present invention, in a microminiature / ultra-thin disk device, a disk clamp means which is forced to be disposed in a narrow arrangement space while securing the rotation accuracy of the rotating shaft is provided from outside. A sufficient fixed load (clamping force) that can withstand the impact load can be secured, and the amount of deformation applied to the disc can be suppressed as much as possible, thereby improving the motor's vibration characteristics and reducing the undulation of the disc. However, it is possible to provide a low-cost clamp structure capable of generating a sufficient clamping force. In general, ultra-small and ultra-thin disk devices, high performance and high reliability can be achieved at the same time, and their value is enormous.
[Brief description of the drawings]
FIG. 1 is a top view of a hard disk drive according to an embodiment of the present invention, in which an upper cover of a casing upper surface is removed and a part is cut away.
FIG. 2 is a sectional view of an essential part taken along a plane passing through a disk rotation center axis in FIG.
FIG. 3 is an enlarged view of the right side of FIG. 2;
FIG. 4 is a cross-sectional view of a main part showing a disc clamp structure of a comparative configuration example for comparison with the disc clamp structure of one embodiment of the present invention.
FIG. 5 is an explanatory diagram showing a relationship between a clamping force and a displacement amount of a screw in the configurations of FIGS. 3 and 4;
[Explanation of symbols]
Reference Signs List 1 base 1a bottom plate 1b side plate 2 upper cover 3 connector 11 actuator arm 12 magnetic head 13 voice coil motor 13a permanent magnet 13b coil 14 arm rotation center shaft 21 magnetic disk 22 disk rotation center shaft 23 bearing 24 rotation shaft 25 spindle Hub 25a Disk holding flange 25b Disk insertion part 25c First clamp ring fitting part 25d Second clamp ring fitting part 26 First clamp ring 26a Magnet holding part 27 Ring-shaped leaf spring 28 Second clamp ring 28a High rigidity portion 28b Spring material pressing portion 29 Screw 30 Rotor magnet 31 Stator coil 32 Printed circuit board 41 Spring / clamp ring

Claims (10)

A bearing fixed to a bottom plate part forming a part of the casing, a rotating shaft rotatably held by the bearing, a spindle hub fixed to the rotating shaft, and a A disk device comprising: a disk carrying a peripheral portion; disk clamping means for fixing the disk to the spindle hub; and a spindle motor for rotating the disk.
The disk clamping means includes: a first clamp ring for clamping an inner peripheral portion of the disk with a flange portion of the spindle hub; a second clamp ring having a plurality of screw insertion holes formed therein; A plurality of screws screwed into the spindle hub through screw insertion holes of a clamp ring, and the screw interposed between the first clamp ring and the second clamp ring and added to the second clamp ring A ring-shaped leaf spring for transmitting the tightening force to the first clamp ring,
The first clamp ring, the second clamp ring, the ring-shaped leaf spring, and the plurality of screws are arranged between the bottom plate portion and the uppermost surface of the spindle hub. A disk device characterized by the above-mentioned. In claim 1,
A disk device, wherein the thickness of the casing is 3.3 mm or less, the diameter of the bearing is 5 mm or more, and the diameter of the center hole of the disk is 10 mm or less. In claim 2,
The uppermost surface of the rotating shaft and the uppermost surface of the spindle hub are flush with each other, and the upper cover forming a part of the casing, and the uppermost surface of the rotating shaft and the uppermost surface of the spindle hub are located in between. Characterized in that they oppose each other with a minute clearance without any intervening member. In claim 2,
The disk device according to claim 1, wherein the bearing is a fluid bearing having a fluid interposed on a bearing surface thereof. In claim 2,
The disk device according to claim 1, wherein a diameter of the screw is 0.8 mm or less. In claim 1,
The disk device, wherein the disk clamping means generates a clamping force of about 10 kgf with a displacement of the screw of about 100 μm. In claim 1,
The second clamp ring includes a high-rigidity portion sandwiched between the screw head of the screw and the spindle hub, and a spring material pressing portion that is thinner than the high-rigidity portion and presses the ring-shaped leaf spring. A disk device comprising: In claim 1,
The spindle hub, the first clamp ring, the second clamp ring, and the ring-shaped leaf spring are formed of a stainless steel material,
A first clamp ring fitting, which is formed on the spindle hub above the flange portion that carries the disk, and has a diameter smaller than a diameter of a center hole of the disk, into which an inner periphery of the first clamp ring fits. And a second clamp ring fitting smaller in diameter than the first clamp ring fitting part, formed above the first clamp ring fitting part and fitted with an inner periphery of the second clamp ring. A disk unit, wherein the unit is provided. In claim 1,
A ring-shaped rotor magnet of the spindle motor is fixed to the first clamp ring, and a stator coil of the spindle motor having substantially the same height as the rotor magnet and facing the rotor magnet with a predetermined clearance is provided. A disk device characterized by being performed. In claim 9,
The first clamp ring is made of a stainless steel material to which the rotor magnet can be fixed by magnetic force.

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