JP2006065959A - Magnetic disk device, clamper for magnetic disk device, and assembly device for magnetic disk device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a small and thin magnetic disk device, a clamper for the magnetic disk device and an assembly device for the magnetic disk device. <P>SOLUTION: The magnetic disk device 1 is provided with: a medium 25; a motor hub 21 arranged with a hollow cylinder part to be clamped 21A rotating around a fixed shaft, a media fitting shaft 21B for fitting the medium 25 and a support part for supporting one surface of the medium 25; a ring-formed elastic body 27 for pressing the other surface of the medium 25 to the support part at the outer periphery of the part to be clamped 21A; and the clamper 26 in a ring shape shrink fit to the part to be clamped 21A in the state of pressing the elastic body 27 to the medium 25. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a magnetic disk device, a magnetic disk device clamper, and an assembly device for a magnetic disk device, and more particularly to a magnetic disk device for attaching a medium to a spindle motor, a clamper for attaching and fixing the medium, and an assembling device for assembling such a magnetic disk device. About.

  Patent Documents 1 to 5 listed below disclose various techniques for fixing a medium to a spindle motor in a magnetic disk device. As shown in FIGS. 12A and 12B, the magnetic disk device disclosed in Patent Document 1 has two media 101 and 102 interposed between a motor hub 100 connected to a spindle motor with a spacer ring 103 interposed therebetween. The two media 101 and 102 are attached and clamped to the motor hub 100 by a disk-shaped leaf spring 104. The leaf spring 104 is fastened to the upper surface of the motor hub 100 by screws 105.

  As shown in FIG. 13, the magnetic disk device disclosed in Patent Document 2 has a groove 100A formed on the outer periphery of the motor hub 100, and the clamper 106 is fitted into the groove 100A by shrink fitting or press fitting. A thrust load is applied by the clamper 106 to fix the media 101 and 102 to the motor hub 100. As shown in FIG. 14, the magnetic disk device disclosed in Patent Document 3 has a taper 100 </ b> B formed on the outer periphery of the motor hub 100, and a clamper 107 is fitted on the taper 100 </ b> B by shrink fitting. Media 101 and 102 are fixed to the motor hub 100 by applying a load. The fixing methods disclosed in Patent Document 2 and Patent Document 3 are effective for a large 3.5-inch magnetic disk device in which the diameter of the motor hub 100 is 20 mm or more.

As shown in FIG. 15, the magnetic disk device disclosed in Patent Document 4 press-fits the clamper 108 having a corrugated cross-sectional shape in the radial direction into the motor hub 100 by shrink fitting or by expanding it in the direction of arrow F. The media 101 and 102 are fixed to the motor hub 100 by applying a thrust load by the wavy cross-sectional shape portion. In the magnetic disk device disclosed in Patent Document 5, as shown in FIG. 16, a clamper 109 having a special cross-sectional shape is press-fitted by shrink fitting, and a thrust load is applied by the special cross-sectional shape of the clamper 109 to apply a motor hub 100. The media 101 and 102 are fixed to each other. In the fixing methods disclosed in Patent Document 4 and Patent Document 5, both the clampers 108 and 109 have a shape in which a thrust load due to elasticity acts after shrink fitting or press fitting.
JP-A-11-96636 Japanese Patent Laid-Open No. 09-120610 Japanese Patent Laid-Open No. 08-321106 Japanese Patent Laid-Open No. 08-180631 Japanese Patent Laid-Open No. 11-16237

  However, in the magnetic disk devices disclosed in Patent Documents 1 to 5 described above, the following points have not been considered.

  In the magnetic disk apparatus shown in FIGS. 12A and 12B, the leaf spring 104 is fixed to the upper surface of the motor hub 100 with screws 105, so that the motor hub 100 needs to have a height corresponding to the processing of the female screw. Become. Further, since the leaf spring 104 is disposed on the upper surface of the motor hub 100 and the head of the screw 105 is present, a height is required to dispose the leaf spring 104 and the screw 105 on the upper surface of the motor hub 100. For this reason, a thickness is required in the axial direction of the motor hub 100, and it has been difficult to reduce the thickness of the magnetic disk device. In particular, in a magnetic disk device in which the lower end of the center axis of the spindle motor is fixed to the base and the upper end is fixed to the cover, a screw for fixing the cover is attached to the center of the upper surface of the motor hub 100. It is difficult, and it is difficult to avoid interference between the leaf spring 104 and the screw 105 and the cover. This type of magnetic disk drive has advantages such as that the center axis of the spindle motor is fixed to the base and the cover, so that the center axis is less touched, and even if an external force is generated on the cover, the cover and the spindle motor are not easily contacted. Suitable for downsizing.

  In the magnetic disk apparatus shown in FIG. 13, when the clamper 106 is attached to the motor hub 100, the inner diameter dimension of the clamper 106 needs to be larger than the outer diameter dimension of the motor hub 100. If the shrink fitting heating temperature of the clamper 106 is increased, the inner diameter expansion amount of the clamper 106 can be increased. In a relatively large magnetic disk device such as the 3.5 inch type or the 2.5 inch type, a sufficient expansion amount can be secured for the inner diameter dimension of the clamper 106 with respect to the outer diameter dimension of the motor hub 100. However, when the miniaturization progresses and the outer diameter (diameter) dimension of the motor hub 100 is reduced to about 6 mm, the expansion amount in the diameter direction of the inner diameter dimension of the clamper 106 is larger than that of the 3.5 inch type. It is drastically reduced to about 1/4 or less. Even if the clamper 106 is made of a material having a high linear expansion coefficient in order to ensure the expansion amount, the heating temperature becomes high. For this reason, the heat from the clamper 106 may affect the media and the spindle motor, and it has been difficult to reduce the size of the magnetic disk device. In the magnetic disk device shown in FIG. 14 as well, it is difficult to reduce the size as in the magnetic disk device shown in FIG.

  In the magnetic disk apparatus shown in FIG. 15, the clamper 108 has a cross-sectional corrugated shape in the radial direction in order to provide springiness, and requires a sufficient waveform length and sufficient waveform height in the radial direction. Yes. For this reason, the reduction in thickness cannot be achieved, and the effective diameter dimension of the motor hub 100 including the diameter of the clamper 108 increases. Therefore, it is difficult to reduce the size of the magnetic disk device. Also in the magnetic disk device shown in FIG. 16, as with the magnetic disk device shown in FIG. 15, the clamper 109 is provided with a special cross-sectional shape having springiness, so that a sufficient length and height (thickness) are obtained. Therefore, it is difficult to reduce the size of the magnetic disk device.

  Further, in the magnetic disk apparatus shown in FIG. 15, it is necessary to insert a claw for expanding the clamper 108 in the direction of arrow F and press-fitting it into the motor hub 100. For this reason, since it becomes difficult to secure a sufficient read / write area of the media as the nail insertion area is secured, it is difficult to reduce the size of the magnetic disk device.

  In the magnetic disk apparatus shown in FIGS. 13 to 16, it is difficult to realize a reduction in size and thickness as compared with the 3.5 inch type or the 2.5 inch type.

  The present invention has been made to solve the above-described problems, and an object thereof is to provide a small and thin magnetic disk device, a magnetic disk device clamper, and a magnetic disk device assembly device.

  A first feature according to an embodiment of the present invention is that, in a magnetic disk device, a disk-shaped medium having a mounting shaft hole, and a hollow cylinder-shaped clamped portion that rotates about a fixed shaft and a mounting shaft hole. A motor hub in which a media mounting shaft for mounting the media and a support portion that supports one surface of the media at the edge of the mounting shaft hole are disposed in the axial direction of the media mounting shaft, and the other surface of the media on the outer periphery of the clamped portion. An elastic body having a ring shape that is pressed against the support portion at the edge portion, and a clamper having a ring shape that is shrink-fitted to the clamper portion in a state where the elastic body is pressed against the medium.

  A second feature of the embodiment of the present invention is that the magnetic disk drive clamper has a ring shape, and a plurality of hub pressing portions that are in contact with the outer periphery of the motor hub and the hub pressing portions are connected to each other. And a connecting portion having a spring property that does not contact the outer periphery.

  A third feature of the embodiment of the present invention is that in the magnetic disk device assembly device, a clamper positioning base for positioning a clamper having a ring shape and a spindle motor connected to the motor hub of the magnetic disk device are assembled. A base positioning base for positioning the base, a clamper positioning base and a first moving mechanism for moving the base positioning base in the horizontal direction, and a clamper positioned on the clamper positioning base are sucked and held, and the clamped and held clamper is heated. The heater head to be moved, the second moving mechanism for moving the heater head in the vertical direction, and the clamper that is attracted and held by the heater head and heated are positioned on the base positioning table by interposing an elastic body between them. Apply pressure to the clamped part of the motor hub of the base. A clamper pressing unit, a third moving mechanism for moving the clamper pressing unit in the vertical direction, and a control unit for controlling each of the first moving mechanism, the second moving mechanism, and the third moving mechanism. Prepare.

  According to the present invention, it is possible to provide a small and thin magnetic disk device, a clamper for the magnetic disk device, and an assembly device for the magnetic disk device.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the description of the embodiment, the same reference numerals are given to components having the same function, and the duplicate description is omitted.

(First embodiment)
[Configuration of magnetic disk unit]
As shown in FIGS. 1A to 1C, the magnetic disk device 1 according to the first embodiment of the present invention includes a disk-shaped medium 25 having a mounting shaft hole 25H and a fixed shaft 20. The support part 21C that rotates to the center and supports the clamped part 21A having a hollow cylindrical shape, the medium attachment shaft 21B for attaching the medium 25 through the attachment shaft hole 25H, and the one surface (lower surface) of the medium 25 at the edge of the attachment shaft hole 25H Elasticity having a ring shape for pressing the other surface (upper surface) of the medium 25 to the support portion 21C at the edge of the mounting shaft hole 25H on the outer periphery of the clamped portion 21A and the motor hub 21 disposed in the axial direction of the mounting shaft 21B. A body 27 and a clamper 26 having a ring shape that is shrink-fitted onto the clamped portion 21A in a state where the elastic body 27 is pressed against the medium 25. There.

  As shown in FIGS. 1 and 2, the magnetic disk device 1 has one end (lower end) of the fixed shaft 20 at the center of the spindle motor fixed to the base 10 with a fixing screw 11 and the other end (upper end) of the fixed shaft 20. A structure in which the fixing screw 13 is fixed to the cover 12 is adopted. With this structure, a small and thin magnetic disk device 1 can be realized. Further, a coil (not shown) of the stator 29 is integrally attached around the fixed shaft 20 inside the base 10, and the magnetic disk device 1 that is much smaller and thinner can be realized.

  The spindle motor is attached and fixed to the base 10 by a fixing screw 11 from the outside (lower surface) side of the base 10. The spindle motor includes a central fixed shaft 20 and a motor hub 21 disposed on the outer periphery thereof. The motor hub 21 rotates around the fixed shaft 20. A fluid bearing 22 is disposed between the fixed shaft 20 and the motor hub 21. A bearing seal 23 is disposed on the upper side of the motor hub 21. A magnet (permanent magnet) 28 is fixed to the lower side (lower surface of the flange) of the support portion 21 </ b> C of the motor hub 21.

  In the magnetic disk device 1 according to the first embodiment, the height of the spindle motor is set to about 0.8 mm from the upper surface of the medium 25 for the purpose of being small and thin. Further, the clamper 26 is manufactured in a ring shape having a height H (thickness) set to a dimension of 0.8 mm or less so as not to protrude from the upper surface of the motor hub 21, and is burned on the clamped portion 21 </ b> A of the motor hub 21. It is fixed. By adopting such a structure, the height of the cover 12 from the base 10 can be set low, and the thickness of the magnetic disk device 1 can be reduced by reducing the thickness. The magnetic disk device 1 according to the first embodiment is a 1-inch type, and can be thinned to a size of 3.5 mm or less.

  As shown in FIG. 2, the magnetic disk device 1 includes a swing arm 31 that swings the upper surface of the medium 25 between a central portion and a circumferential portion, and a magnetic head 30 disposed at the tip of the swing arm 31. And an actuator 32 that performs a swing operation of the swing arm 31.

  In the clamper 26, the length L (width) in the radial direction is set to about 0.7 mm or less so that the magnetic head 30 can move as far as possible to the center (inner circumference) of the medium 25. Even if the length L of the clamper 26 is set to such a dimension, the clamper 26 can obtain a sufficient clamping force. As described above, since the outer diameter of the clamper 26 can be reduced, the read / write area of the medium 25 can be used as effectively as possible, and the magnetic disk device 1 having a small size and a thin storage capacity can be realized. can do.

  The outer shape of the clamper portion 21A of the motor hub 21 is configured by a simple columnar shape having no groove, taper, or the like. In the first embodiment, since the fluid bearing 22 is used in the spindle motor, the clamped portion 21A is actually formed in a hollow cylindrical shape (cylindrical shape). Compared to the case where there is a groove, a taper, etc., the clamper 26 can be easily fitted to the clamped portion 21A of the motor hub 21 if the inner diameter portion of the clamper 26 is heated and expanded at the minimum shrink fitting temperature. It is possible to prevent damage to the media 25, spindle motor, and the like due to heat. Further, by configuring the outer diameter shape of the clamper portion 21A in a simple shape, it is possible to easily manage the dimensions such as the outer diameter size of the clamper portion 21A and the inner diameter size of the clamper 26.

[Clamper configuration]
As shown in FIGS. 1, 2, and 3, the clamper 26 is a ring, and connects the hub pressing portion 26A with a plurality of hub pressing portions 26A that are in contact with the outer periphery of the clamper portion 21A of the motor hub 21. The connecting portions 26B having spring properties that do not contact the outer periphery of the clamped portion 21A are alternately provided. Furthermore, the clamper 26 includes a pin insertion hole 26H for expanding and deforming the inner diameter of the hub pressing portion 26A by an external force.

  In the first embodiment, the clamper 26 is formed by a ring (annular ring) having an outer diameter of 7.0 mm, an inner diameter of 5.6 mm, and a thickness of 0.7 mm. The hub pressing portion 26A is an area having an inner diameter of 5.6 mm. The clamper 26 is shrink-fitted and fixed to the clamped portion 21A by the hub pressing portion 26A. The connecting portion 26B connects the adjacent hub pressing portions 26A with a continuous curved shape instead of discontinuity so as not to cause stress concentration. In other words, the cross-sectional area of the connecting portion 26B is smaller than the cross-sectional area of the hub pressing portion 26A. In the first embodiment, the continuous portion 26B can be easily formed by providing the clamper 26 with the cutout portion 26N having an arc shape. The cutout portion 26N is formed by a cutting tool having a radius R1 of 1.0 mm to 1.8 mm, for example, and the minimum width dimension of the connecting portion 26B is set to 0.2 mm, for example.

  The clamper 26 is preferably formed of a material having a larger linear expansion coefficient than that of the clamper used in the 3.5-inch magnetic disk apparatus. When the clamper 26 is shrink-fitted and fixed to the clamper portion 21A of the motor hub 21, the inner diameter dimension of the clamper 26 is expanded by heating larger than the outer diameter dimension of the clamper section 21A, and the clamper 21 is inserted into the clamper section 21A. It is necessary that the clamper 26 tightens the clamped portion 26A after cooling. In the magnetic disk device 1, since the outer diameter of the clamped portion 21A is small, the clamper is set to the same material and shrink-fit temperature for tightening the motor hub having a large outer diameter of the 3.5 inch magnetic disk device. However, since a large expansion / contraction ratio cannot be ensured, the clamper 26 cannot be shrink-fitted and fixed to the clamped portion 21A with a sufficient fastening force.

  If the linear expansion coefficient of the clamper 26 is larger than necessary compared with the linear expansion coefficient of the motor hub 21, the upper limit of the operating temperature (operating temperature) of the magnetic disk device 1, for example, 80 ° C. is reached. The amount of thermal expansion is relatively large. As a result, there is a possibility that the interference between the clamper 26 and the clamper portion 21A is lowered, and the clamper 26 is detached from the clamper portion 21A. For example, when the outer diameter of the motor hub 21 is set to about 6 mm, the motor hub 21 is made of ferritic stainless steel, specifically, SUS430, and the clamper 26 is made of an aluminum alloy, Since the thermal expansion coefficient is twice or more, the clamper 26 is detached from the clamped portion 21A in the vicinity of the operating temperature. Furthermore, if an aluminum-based alloy is used as it is for the clamper 26, dust is generated and surface treatment is required.

  In the first embodiment, it is preferable that the clamper 26 is made of austenitic stainless steel which generates less dust such as rust and has the largest linear expansion coefficient among stainless steels. Furthermore, it is practical to manufacture the clamper 26 from SUS304 that does not generate outgas (for example, sulfur gas) among austenitic stainless steels.

  If the shrink-fitting heating temperature of the clamper 26 is increased, the expansion amount of the inner diameter dimension of the clamper 26 can be increased. However, when the clamper 26 is inserted into the clamped portion 21A of the motor hub 21, the medium 25 comes into contact with the 25 may be affected by heat. Specifically, when the clamper 26 is heated to about 300 ° C. and inserted into the clamped portion 21A, when the medium 25 on which the servo signal is recorded in advance is used, the servo signal near the clamper 26 is attenuated, The rubbing film applied to the surface may be deteriorated.

  The optimum shrink fitting heating temperature that does not affect the medium 25 is, for example, about 150 ° C. The shrink fitting heating temperature is set, the dimensional tolerance between the inner diameter of the clamper 26 and the outer diameter of the clamped portion 21A and the tightening allowance are optimized, and the clamper 26 is set to the linear expansion coefficient of SUS304. When the clearance between the clamper 26 and the clamped portion 21A and the tightening allowance after cooling are calculated, the clearance can be secured to 1 μm or more, and the tightening allowance can be secured to 5 μm or more. Even when the temperature rises to 80 ° C., which is the operating temperature, it is possible to ensure a tightening allowance of 1 μm or more.

  As shown in FIGS. 1B and 3, the clamper 26 is capable of replacing parts when a failure occurs in the media 25, the spindle motor, etc. after the shrink fit is fixed to the motor hub 21. It has. That is, the clamper 26 has a spring property when fixed by shrinkage fitting, and increases the tightening force of the hub pressing portion 26A. When repairing, the clamper 26 is plastically deformed by an external force and is removed from the clamped portion 21A. 26B. In the first embodiment, the hub pressing portion 26A and the connecting portion 26B are arranged in four equal portions, and the pin insertion holes 26H are similarly arranged in four equal portions.

  In the clamper 26, a pin (not shown) of the chuck cylinder is inserted into the pin insertion hole 26H and is forcibly expanded by the chuck cylinder in the normal direction from the center, as shown in FIG. The portion in contact with the outer diameter of the clamped portion 21A extends outward, and the connecting portion 26B not in contact with the outer diameter of the clamped portion 21A can be deformed inward. Thus, by providing the clamper 26 with the connecting portion 26B, the clamper 26 after being shrink-fitted and fixed to the motor hub 21 can be easily removed. Therefore, in the product inspection after the assembly of the magnetic disk device 1, when a failure is detected in the media 25, the motor hub 21, etc., the clamper 26 can be removed from the motor hub 21 and the parts can be replaced.

    As described above, when the clamper 26 is heated at 150 ° C., the rib pressing portion 26A mainly expands to widen the inner diameter, and during repair, the connecting portion 26B buckles and expands, Is configured to widen. For this reason, shrink fitting will become difficult if many connection parts 26B are made. Therefore, the connecting portion 26B is preferably 3 to 8 locations, and is preferably arranged equiangularly on the ring.

[Modification of clamper]
Note that the number of the connecting portions 26B of the clamper 26 is not limited to four. For example, the connection part 26B can be provided in the clamper 26 in the number of arrangements equal to or greater than the third grade or the fifth grade. However, in the second equal arrangement of the connecting portions 26B, the number of locations having springiness is reduced, and the clamper 26 cannot obtain a sufficient tightening force. In addition, when using a chuck cylinder having a claw other than a pin, the clamper 26 may be widened by another method, and the clamper 26 does not necessarily have to have the pin insertion hole 26H.

  Further, as shown in FIG. 5, a clamper 26 having a notch portion 26n having a notch radius R2 smaller than the notch radius R1 of the notch portion 26N of the clamper 26 shown in FIG. 3 can be used. When the notch radius R is reduced, the area where the elastic body 27 is pushed increases, and the fixing torque of the medium 25 can be increased. Conversely, if the notch radius R is too small, when repairing, when the inner diameter of the clamp 26 is increased, the edge between the contact portions of the notch portion 26n and the clamper portion 21A is not fully spread and the clamper is clamped. The clamper 26 cannot be removed by contacting the part 21A. In such a case, as shown in FIG. 6, the clamper 26 is further provided with a cutout portion 26m having a cutout radius R3 at the contact portion with the clamper portion 21A.

[Configuration of elastic body]
As shown in FIGS. 1 (A), 1 (C), and 7, an elastic body 27 is inserted between the clamp 26 and the medium 25 that are shrink-fitted and fixed to the clamped portion 21A of the motor hub 21. Yes. The elastic body 27 is configured by a tapered hollow cylindrical body that presses the upper surface of the medium 25 on the circumferential side of the medium 25 from the position where the elastic body 27 contacts the clamper 26. In the first embodiment, a disc spring can be practically used for the elastic body 27. The disc spring can apply a large load with a small amount of deflection in a relatively small space. The upper diameter dimension L1 of the elastic body 27 shown in FIG. 7 is about 5.6 mm, the lower diameter dimension L2 is about 7.0 mm, the height H1 of the taper portion is about 0.4 mm, and the height H2 of the vertical portion. When each elastic body 27 is set to 0.2 mm and a compressive stress of 0.1 mm is applied to the elastic body 27, a thrust load of about 15 N is generated.

  In the case of a small magnetic disk device, since the diameter of the medium is small, the weight of the medium, the inertia when the spindle motor rotates, and the starting torque of the spindle motor are small. If the magnetic disk device is about 1 inch or less, a sufficient media fixing torque can be obtained with this thrust load.

  When the clamper 26 is heated and inserted into the clamped portion 26A of the motor hub 21, the thruster 26 is brought into close contact with the medium 25 without the elastic body 27 interposed, and a thrust load is applied, When the height H is set to 0.5 mm, it can be calculated that the clamper 26 contracts about 0.7 μm from the center of the height H. Since the clamper 26 contracts after cooling, a sufficient thrust load cannot be applied to the medium 25, and a sufficient fixing torque of the medium 25 cannot be ensured.

  Thus, by providing the elastic body 27 having a simple shape between the medium 25 and the clamper 26, a sufficient thrust load can be easily generated, so that the fixing torque of the medium 25 to the motor hub 21 is increased. can do.

[Configuration of assembly equipment]
As shown in FIG. 8, the assembly device 50 for realizing the shrink-fitting fixing of the magnetic disk device 1 according to the first embodiment includes a clamper positioning base 52 for positioning the clamper 26 having a ring shape, and a magnetic disk. A base positioning base 51 for positioning the base 10 to which the spindle motor connected to the motor hub 21 of the apparatus 1 is assembled, and a first moving mechanism for moving the clamper positioning base 52 and the base positioning base 51 in the horizontal direction (X direction). 54, the clamper 26 positioned on the clamper positioning table 52 by suction, and a heater head 55 that heats the clamper 26 held by suction, and a second movement that moves the heater head 55 in the vertical direction (Z direction). The mechanism 58 and the clamper 26 that is attracted and held by the heater head 55 are heated to a medium. The clamper pressurizing unit 60 and the clamper pressurizing unit 60 are vertically fitted to the clamper unit 21A of the motor hub 21 of the base 10 positioned on the base positioning base 51 with the elastic body 27 interposed therebetween. A third moving mechanism 61 that moves in the direction, and a control unit 65 that controls each of the first moving mechanism 54, the second moving mechanism 58, and the third moving mechanism 61 are provided. Connected to the control unit 65 is an input unit 66 for an operator to operate the assembling apparatus 50. Although not shown, the base positioning stand 51 is provided with three pins for supporting the spindle motor from below the base.

  The clamper positioning table 52 and the base positioning table 51 are mounted on the same bed 51 that reciprocates in the horizontal direction by the first moving mechanism 54. By the reciprocating motion of the bed 51, the clamper positioning base 52 and the base positioning base 51 can be moved to the processing position where the shrink fit fixing is alternately performed. It is practical to construct the first moving mechanism 54, the second moving mechanism 58, and the third moving mechanism 61 by, for example, an air cylinder system or a hydraulic cylinder system, for simple and inexpensive system construction.

  A vacuum device 56 and a heater 57 are further connected to the heater head 55. Although not shown in detail, a plurality of suction holes connected to the vacuum device 56 are provided on the bottom surface of the heater head 55, and the clamper 26 can be suction-held on the bottom surface of the heater head 55. . Further, the clamper 26 attracted and held by the heater head 55 can be heated to the shrink fitting temperature by the heater 57. The heater head 55 sucks and holds the clamper 26 positioned on the clamper positioning table 52 at the processing position by the second moving mechanism 58. Further, the heater head 55 supplies the clamper 26 that is attracted and held and heated at the processing position to the base 10 positioned on the base positioning table 51 by the second moving mechanism 58.

  The clamper pressurizing unit 60 press-inserts the clamper 26 supplied to the base 10 by the heater head 55 into the clamper unit 21 </ b> A of the motor hub 21 at the processing position by the third moving mechanism 61. As shown in FIGS. 8 and 9, the clamper pressing unit 60 is opened and closed in the horizontal direction (X direction) by the third moving mechanism 61. Further, as shown in FIG. 9, the heater head 55 is provided with a vertical groove portion (a relief portion) 55A, and a part of the clamper 26 attracted and held by the heater head 55 is exposed to the groove portion 55A. The tip pressurizing unit 60A of the clamper pressurizing unit 60 presses a part of the clamper 26 exposed from the groove 55A of the heater head 55.

[Assembly method of magnetic disk unit]
Next, a method of assembling the magnetic disk device 1 using the above-described assembling device 50 (method of fixing the clamper 26 to the motor hub 21 by shrink fitting) will be described.

  First, in the assembling apparatus 50 shown in FIG. 8, the clamper 26 is supplied onto the clamper positioning table 52 and the clamper 26 is positioned. On the other hand, the base 10 on which the spindle motor having the motor hub 21 connected is mounted on the base positioning base 51 is supplied, and the base 10 is positioned.

  The clamper positioning table 52 is set at the processing position by the first moving mechanism 54. The heater head 55 is lowered by the second moving mechanism 58 to attract and hold the clamper 26 positioned on the clamper positioning table 52. After sucking and holding, the heater head 55 is raised, and the clamped and held clamper 26 is heated by the heater head 55 at the same time.

  The clamper positioning table 52 is retracted from the processing position by the first moving mechanism 54, and the base positioning table 51 is set at the processing position. In the first embodiment, before the base positioning stand 51 is set at the processing position, as shown in FIG. 10A, the medium mounting shaft 21B of the motor hub 21 incorporated in the base 10 has a medium 25. Is attached, and an elastic body (belleville spring) 27 is disposed on the clamped portion 21A.

  The heater head 55 is lowered by the second moving mechanism 58, and the clamper 26 whose inner diameter is expanded by heating the heater head 55 is inserted into the clamped portion 21 </ b> A of the motor hub 21. At this time, the motor hub 21 supports the lower surface of the motor hub 21 with a pin from a hole drilled in the base so that the thrust load is not directly applied to the bearing to be broken. After this insertion, as shown in FIGS. 9 and 10B, the tip pressurizing portion 60A of the clamper pressurizing portion 60 enters from the side into the groove portion 55A of the heater head 55 and presses the upper surface of the clamper 26. wear. In this state, the heater head 55 is raised. Since the clamper 26 applies a load in the axial direction of the spindle motor while controlling the applied pressure so that the deformation amount of the elastic body 27 is maintained at the tip pressurizing portion 60A, the clamper 26 is not lifted by the elastic body 27. Since the clamper 26 is inserted into the clamped portion 21A, the heated clamper 26 is immediately transferred to the tip pressurizing portion 60A of the clamper pressurizing portion 60, and the heater head 55 is immediately raised. The heater head 55, which is a heat source, can be moved away from the heat source 25, and the heat of the clamper 26 can be absorbed through the clamper pressurizing unit 60 to immediately cool the clamper 26 to room temperature.

  As a result, the clamper 26 can be shrink-fitted and fixed to the clamped portion 21A of the motor hub 21, and the medium 25 can be fixed to the motor hub 21 with sufficient fixing torque using the elasticity of the elastic body 27. Damage to the media 25, the motor hub 21, etc. due to heat can be prevented.

  As described above, according to the first embodiment, the motor hub 21 having the clamped portion 21A having a simple outer diameter and the clamper having a simple shape that is shrink-fitted and fixed to the clamped portion 21A. 26 and the elastic body 27 having a simple shape for obtaining a thrust load, the structure for mounting and fixing the medium 25 to the motor hub 21 can be made simple and small, so that the magnetic disk device 1 can be reduced in size. It can be made thin.

  Furthermore, by selecting an appropriate material for the clamper 26, the generation of dust can be reduced and the life of the magnetic disk device 1 can be extended.

  Further, since the clamper 26 is provided with the connecting portion 26B and the like, the clamper 26 can be removed after the shrink-fitting is fixed, so that the repairability of the magnetic disk device 1 can be improved.

  Furthermore, since the heater head 55 that presses the clamper 26 and the clamper pressurizing unit 60 that actually inserts the clamper 26 into the motor hub 21 are independently operated, damage from the clamper 26 and the heater head 55 due to heat. The medium 25 becomes difficult to receive, and the productivity of the magnetic disk device 1 can be improved in the assembling apparatus 50.

(Second Embodiment)
The second embodiment of the present invention describes an example in which the shape of the clamper 26 incorporated in the magnetic disk device 1 according to the first embodiment is further improved.

  The clamper 26 shown in FIG. 11A further includes a notch 261 along the outer periphery of the clamper 26 shown in FIG. The notches 261 are disposed on both sides of the pin insertion hole 26H. The notch 261 can easily deform the clamp 26 with a weak external force, and can improve the repairability of the magnetic disk device 1.

  A clamper 26 shown in FIG. 11B includes a notch 262 in which the notch radius R of the notch 26m of the clamper 26 shown in FIG. 6 is further reduced. Similarly, the notch 262 can easily deform the clamp 26 with a weak external force, and the repairability of the magnetic disk device 1 can be improved.

  In addition, this invention is not limited to the above-mentioned embodiment, It can change variously. For example, the above embodiment has been described by taking the magnetic disk device 1 having one medium 25 as an example, but the present invention may be applied to a magnetic disk device having a plurality of media.

(A) is a side view (F1-F1 sectional view) of the main part of the magnetic disk apparatus according to the first embodiment of the present invention, (B) is a top view of the motor hub and clamper of the magnetic disk apparatus, and (C). It is a principal part expanded sectional view of a motor hub, a clamper, an elastic body, and a medium. FIG. 2 is an exploded perspective view showing the overall structure of the magnetic disk device shown in FIG. 1. FIG. 2 is a top view of a clamper of the magnetic disk device shown in FIG. 1. It is a top view which shows the repair property of the clamper shown in FIG. It is a top view which shows the modification of the clamper shown in FIG. FIG. 6 is a top view showing a modified example of the clamper shown in FIG. 5. FIG. 2 is a perspective view of an elastic body of the magnetic disk device shown in FIG. 1. It is a schematic block diagram of the assembly apparatus of the magnetic disk apparatus shown in FIG. 8A is a side view of a main part showing a heater head and a clamper pressing unit of the assembling apparatus shown in FIG. 8, and FIG. 9B is a top view of a main part showing a heater head and a clamper pressing part of the assembling apparatus shown in FIG. It is. (A) and (B) are assembly process diagrams of the magnetic disk device. (A) is a principal part top view of the clamper of the magnetic-disk apparatus based on the 2nd Embodiment of this invention, (B) is a principal part top view which shows the modification of the clamper shown to (A). (A) is a principal part side view which shows the partial cross section of the magnetic disc apparatus based on patent document 1, (B) is a top view of the motor hub, clamper, and screw which are shown to (A). 10 is a cross-sectional view of a main part of a magnetic disk device according to Patent Document 2. FIG. 10 is a cross-sectional view of a main part of a magnetic disk device according to Patent Document 3. FIG. 10 is a cross-sectional view of a main part of a magnetic disk device according to Patent Document 4. FIG. 10 is a cross-sectional view of a main part of a magnetic disk device according to Patent Document 5. FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Magnetic disk apparatus, 10 ... Base, 11, 13 ... Fixing screw, 12 ... Cover, 20 ... Fixed shaft, 21 ... Motor hub, 21A ... Clamper part, 21B ... Media mounting shaft, 21C ... Support part, 22 ... Fluid Bearing, 23 ... Bearing seal, 25 ... Media, 25H ... Mounting shaft hole, 26 ... Clamper, 26A ... Hub holding part, 26B ... Connection part, 26N, 26n, 26m ... Notch part, 26H ... Pin insertion hole, 27 ... Elasticity Body, 28 ... magnet, 29 ... stator, 30 ... magnetic head, 31 ... swing arm, 32 ... actuator, 51 ... base positioning base, 52 ... clamper positioning base, 54 ... first moving mechanism, 55 ... heater head, 58 ... 2nd moving mechanism, 60 ... Clamper pressurizing part, 61 ... 3rd moving mechanism, 65 ... Control unit.

Claims (10)

A disc-shaped medium having a mounting shaft hole;
Rotating around a fixed shaft, a hollow cylindrical clamped portion, a media mounting shaft for mounting the media through the mounting shaft hole, and a support portion for supporting one surface of the media at the edge of the mounting shaft hole A motor hub disposed in the axial direction of
On the outer periphery of the clamper part, an elastic body having a ring shape that presses the other surface of the medium against the support part at the edge of the attachment shaft hole;
A clamper having a ring shape shrink-fitted on the clamped portion in a state where the elastic body is pressed against the medium;
A magnetic disk drive comprising:   The magnetic disk device according to claim 1, wherein the elastic body is in contact with the other surface of the medium on a circumferential side of the medium from a position where the elastic body is in contact with the clamper.   3. The magnetic disk apparatus according to claim 1, wherein the elastic body is a disc spring.   The clamper includes a plurality of hub pressing portions that are in contact with the outer periphery of the clamped portion, and a connecting portion that has a spring property that connects the hub pressing portions and does not contact the outer periphery of the clamped portion. The magnetic disk device according to claim 1.   5. The magnetic disk drive according to claim 4, wherein the clamper includes a pin insertion hole for expanding and deforming an inner diameter of the hub pressing portion by the external force.   6. The magnetic disk apparatus according to claim 1, wherein the motor hub is made of ferritic stainless steel, and the elastic body and the clamper are made of austenitic stainless steel. A plurality of hub retainers that contact the outer periphery of the motor hub;
A clamper for a magnetic disk device, characterized in that it is a ring in which the hub pressing portions are connected to each other and a connecting portion having a spring property that does not come into contact with the outer periphery of the motor hub.   8. The clamper for a magnetic disk device according to claim 7, wherein the hub pressing portion is provided with a pin insertion hole for expanding and deforming an inner diameter thereof by an external force.   9. The clamper for a magnetic disk device according to claim 7, wherein the clamper is made of austenitic stainless steel. A clamper positioning table for positioning a clamper having a ring shape;
A base positioning table for positioning a base on which a spindle motor connected to a motor hub of a magnetic disk device is mounted;
A first moving mechanism for moving the clamper positioning table and the base positioning table in a horizontal direction;
A heater head that holds the clamper positioned on the clamper positioning table by suction, and heats the clamper held by suction;
A second moving mechanism for moving the heater head in a vertical direction;
The clamper pressurizing the clamper held and heated in the heater head by pressurizing and fitting the clamper to the clamped portion of the base motor hub positioned on the base positioning table with an elastic body interposed between the clamper and the medium. And
A third moving mechanism for moving the clamper pressurizing portion in the vertical direction;
A control unit for controlling each of the first moving mechanism, the second moving mechanism, and the third moving mechanism;
An assembly apparatus for a magnetic disk device, comprising: