JP2003203412A - Magnetic disk device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a magnetic disk device which can correct the center deviation of a spindle hub and a magnetic disk, and can mount a magnetic disk on the spindle hub coaxially, has a high track pitch, and is suitable for the recording and the reproduction of data. <P>SOLUTION: An aligning member 6 comprises a first inclined plane 6a opposed to a chamfer 1b of the inner periphery end of the center hole 1a of the magnetic disk 1, and a second inclined plane 6b opposed to a guide part 2b provided at the tip part of the disk insertion cylindrical part 2a of the spindle hub 2. When axial force is added during cramping, center deviation is corrected by horizontal reactive force caused in a contact surface between the first inclined plane 6a and the chamfer 1b and between the second inclined plane 6b and the guide part 2b, and the central axis 1c of the magnetic disk 1 is made coincident with and fixed to the central axis 2d of the spindle hub 2. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for accurately aligning and assembling a magnetic disk in a magnetic disk device, and in particular, mounting and fixing the magnetic disk on a spindle hub accurately and coaxially. And an arrangement of an aligning member for

[0002]

2. Description of the Related Art FIG. 16 is a perspective view showing a structure of a conventional magnetic disk device which is widely and generally used. In FIG. 16, one magnetic disk 1 or a plurality of magnetic disks 1 are laminated and fixed on a spindle hub 2 rotated by a spindle motor 5, and the magnetic head 101 is provided on both sides or one side of the magnetic disk 1. It is arranged so as to be rotatable so as to intersect with the rotation direction of 1. When the spindle motor 5 rotates, the air flow generated between the surface of the magnetic disk 1 and the magnetic head 101 causes the magnetic head 101 to slightly float above the magnetic disk 1.
The magnetic head 101 is fixed to the tip of an actuator 102, and a voice coil motor 104 is provided on the actuator 102 at the other end of the actuator shaft 103, which is the rotation shaft of the actuator.

The magnetic head 101 is a voice coil motor 1.
The drive force of 04 causes the actuator shaft 103 to rotate around the actuator shaft 103, and moves on the magnetic disk 1 in the radial direction. By rotating the spindle motor 5, that is, the rotation of the magnetic disk 1 and the rotation of the magnetic head 101, the magnetic head 101 is accessed to an arbitrary position of the data track, and magnetic information is recorded on the data track spirally drawn on the magnetic disk 1. It is possible to read and write the recorded data.

In order to read and write data accurately, the magnetic head 101 needs to accurately follow the data track on the magnetic disk 1. In order to follow the data track of the magnetic head 101, the actuator 102 is detected in the direction in which the current position is detected from the servo information which is drawn at a plurality of discrete points in advance at equal angular intervals on the data track and the deviation from the data track is corrected. That is, it is performed by rotating the magnetic head 101. The flying height of the magnetic head 101 is about several tens of nm, and the intervention of dust between the magnetic head 101 and the magnetic disk 1 damages the magnetic head 101 and the magnetic disk 1 and causes a failure. Therefore, the magnetic disk 1 is mounted and assembled in the magnetic disk device in a clean room, and after the assembly, the cover 105 is hermetically sealed.

Now, a conventional method of drawing servo information on the magnetic disk 1 (hereinafter referred to as servo write) will be described. At the time of servo write, a head disk assembly (hereinafter, referred to as a magnetic disk and a magnetic head) is mounted.
In the state of HDA), the device is mounted on a device that performs servo writing, that is, a servo track writer (hereinafter, referred to as STW). A method called a push pin method is used to mount the HDA on the STW and perform servo writing. In this push pin method, the actuator drive pin attached to the STW is inserted into the hole provided in the actuator of the HDA in advance, the HDA is mounted on the STW, and the HDA actuator is precisely rotated by the drive pin. Servo write is performed using a magnetic head.

Servo writing by the push pin method has two major problems. The first problem is the undulation of the data track due to the servo information recorded on the magnetic disk, and the second problem is that the productivity is low because the HDA must be individually mounted on the STW. That's what it means. As described above, in order to read and write data accurately, it is necessary for the magnetic head to accurately follow the data track spirally drawn on the magnetic disk. If the data track deviates from an ideal spiral curve due to the occurrence of waviness of the data track recorded on the magnetic disk, the magnetic head cannot follow the data track accurately. Therefore, there are severe restrictions on the occurrence of waviness of the data track in the radial direction and the rotating direction of the magnetic disk.

The main cause of the waviness of the data track in the push-pin type servo write is that the spindle system is rotated and touched during the servo write.
They are roughly classified into those resulting from the positioning of the actuator system.

First of all, the main causes of the rotary contact of the spindle system are rotation synchronous runout and asynchronous rotary runout due to the bearing of the spindle motor and its mounting. With respect to the rotation-synchronized runout, if the displacement and the phase do not change, that is not a particular problem. The non-rotational synchronization shake has an adverse effect of causing waviness of the data track.
Asynchronous rotation runout occurs due to a processing error of a component that constitutes a bearing, and can be improved to some extent by improving the processing precision of the component, but an increase in precision causes a problem of cost increase. It is also possible to reduce non-synchronous rolling contact by using fluid bearings. However, at high temperatures, the viscosity of the fluid used for the fluid bearing decreases. If we mainly consider the viscosity of the fluid at high temperature,
At low temperature, the viscosity becomes too large, which causes a problem that the load on the bearing increases and the power consumption increases at low temperature.

There is non-rotational synchronous runout due to mechanical resonance of the spindle motor and the magnetic disk. In the case of a spindle motor using a normal ball bearing, two ball bearings arranged in the axial direction are preloaded and used. As one means for reducing the mechanical resonance of the spindle motor, it is preferable to increase the rigidity of the bearing. Therefore, it is conceivable to increase the preload as a concrete means, but this method causes a problem that the rolling fatigue life and impact resistance of the bearing are reduced due to the increase of the contact pressure. Again 2
It is conceivable to increase the axial spacing of the three bearings, but this is difficult to improve significantly due to dimensional limitations. Further, it is possible to reduce the resonance amplitude by using a fluid bearing, but as described above, the power consumption at the time of low temperature use due to the temperature characteristic becomes a problem.

As described above, none of the above-mentioned improvement methods has a bad effect, and no truly effective improvement method is found. In the servo write by the push pin method, a waviness is caused in the servo track due to the non-rotational synchronization deviation of the spindle system. I will end up.

Next, what is caused by the positioning of the actuator system will be described below. In the method of rotating the HDA actuator by the STW drive pin, which is a feature of the push pin method, in the surface roughness of the contact portion between the drive pin that transmits the external force to the HDA actuator and the hole of the HDA actuator, and the actuator bearing The waviness of the data track occurs due to the positional feed accuracy of the magnetic head due to the shape error and the mounting error. There is a limit in the surface feed accuracy of the contact portion between the drive pin and the HDA actuator, and the position feed accuracy of the magnetic head due to the shape error and mounting error of the actuator bearing, and it is written as a spiral curve which is an ideal data track. A gap is generated between the data track and the servo information that is embedded.

Recently, in order to improve the data transfer rate, the actuator has been made smaller and lighter so that it can move between data tracks at a high speed, and further, the size and thickness have been reduced in accordance with the increase in the number of stacked magnetic disks corresponding to the increase in capacity. Has come to be needed. For this reason, problems such as an increase in mechanical resonance amplitude due to a decrease in actuator rigidity and a positional deviation due to wind disturbance have arisen. As described above, in the push-pin type servo write, undulation occurs in the servo track due to the positioning error of the actuator system.

As described in detail above, the data tracks servo-written by the push-pin method are accompanied by undulations that deviate from the ideal spiral shape. As a result, when reading and writing data, it hinders the magnetic head from accurately following the data track, which adversely affects the increase in position error and the error rate.

Next, the push-pin type servo write has a problem of productivity. With the recent increase in the density of magnetic disk devices, the amount of data tracks per magnetic disk has increased and the track pitch has narrowed accordingly. Due to this increase in servo information per data track, the amount of servo information to be recorded in servo write has increased. Therefore, productivity increases due to increase in servo write time, and it becomes necessary to increase the number of very expensive STWs, resulting in large capital investment.

Proposed as a new servo write technique for solving the problem of servo write by the push pin method is a method of performing servo write on the magnetic disk in advance before attaching the magnetic disk to the spindle hub. . That is, the servo information is drawn on the magnetic disk in advance, and the magnetic disk (pre-servo write disk) on which the servo information is drawn is placed on the spindle hub of the magnetic disk device, and fixed to the spindle hub by a clamp so that it can rotate integrally. Is the way to do it. This method can be further classified into two types according to the method of drawing a data track on the magnetic disk.

The first method is a method called a single plate servo write. STW used for single plate servo light is
It has a spindle motor, a magnetic head, an actuator, and a voice coil motor. A magnetic disk is integrally and rotatably mounted coaxially on the STW spindle motor, and a data track is written on the magnetic disk by the STW magnetic head. The STW used for this single-plate servo write writes servo data on a magnetic disk by an actuator and a magnetic head mounted on the STW.

Since the magnetic head is directly driven and written by the actuator mounted on the STW, it is possible to reduce the occurrence of an error due to the surface roughness of the contact portion of the drive pin connecting with the actuator of the HDA. In addition, the STW has a higher degree of dimensional design freedom than the HDA, and because it is a small amount of equipment, the cost limit is relaxed compared to mass-produced products. Therefore, it is necessary to use high-precision parts to improve rotation accuracy. You can Furthermore, since STW does not need to be small, there are few restrictions in terms of size and cost, and materials and structures with high rigidity can be used, and the shape, weight, and moment that are not easily affected by wind turbulence are used. be able to. Furthermore, since the restrictions in terms of dimensions and cost are reduced, it is possible to use a fluid bearing such as an air bearing having extremely small non-rotational synchronous contact with respect to rotational runout of the spindle system. Can be reduced. Even if the fluid bearing is used, it can be operated under a controlled temperature, so that the characteristic change due to the temperature change can be reduced, and the limitation of power consumption can be eased.

That is, since the STW is not a mass-produced product like the HDA, the degree of freedom in design is very high and the resonance amplitude, that is, the non-rotation synchronous touch due to the improvement in mechanical rigidity can be reduced, and the rotation accuracy can be improved. it can. It is also possible to stack a plurality of magnetic disks at one time and mount them on a spindle motor to perform servo writing so that servo writing can be performed on many magnetic disks in a short time. Therefore, according to the single-plate servo write method, it is possible to suppress the deviation such as the waviness of the data track in the HDA by using the conventional push pin method as compared with the individual servo write method.

The second method is a method called magnetic transfer. To record servo information on a magnetic disk by the magnetic transfer method, the surface of a master information carrier on which magnetic irregularities corresponding to the servo information to be recorded is previously provided is brought into contact with the surface of the magnetic disk on which the servo information is to be recorded. , The magnetic pattern corresponding to the magnetic irregularities on the surface of the master information carrier is transferred to the magnetic disk.

According to this method, if the positional accuracy of the magnetic unevenness corresponding to the servo information previously provided on the master information carrier with respect to the servo track is accurate, the positional accuracy of the servo information transferred and recorded on the magnetic disk will be described. Can also be accurate. Also, restrictions on equipment size, cost, and creation time for creating the master information carrier are much relaxed compared to mass-produced magnetic disk devices.
It is technically possible to improve the positional accuracy of the magnetic unevenness provided on the master information carrier. Further, in the servo write method using a magnetic head such as the push pin method or the single plate servo write method, only line information can be drawn, whereas in the magnetic transfer method, line information can be drawn. As a result, a huge amount of servo information can be instantly written on the magnetic disk, and productivity can be improved.

[0021]

In the single-plate servo write system and magnetic transfer system using a pre-servo write disk, data track rotation synchronous shake occurs due to misalignment that occurs when the pre-servo write disk is mounted in the magnetic disk device. Is a problem.

That is, in the conventional push pin method, since the servo write is performed after the HDA in which the magnetic disk is mounted and fixed on the spindle hub is completed, the rotation synchronous runout of the spindle motor and the misalignment between the spindle rotation center axis and the disk rotation center axis. Was not a problem as long as it was within the allowable range of rotation balance. That is, even if the center axis of the data track drawn on the magnetic disk is not coaxial with the center axis of the magnetic disk or does not have an ideal spiral curve, the same during servo write and data read / write. Since the HDA is used, the rotational runout of the magnetic disk with respect to the magnetic head is similarly synchronized.
Therefore, the data track did not swing with respect to the magnetic head flying above the magnetic disk, and it did not hinder the accurate tracking of the data track by the magnetic head.

On the other hand, in the servo write method using the pre-servo write disk, the pre-servo write disk is mounted on the spindle hub connected to the spindle motor of each magnetic disk device. Therefore, the waviness of the data track drawn on the pre-servo write disk is
Even if it is rotation-synchronized, it means that the data track is wobbling when viewed from the magnetic head of the magnetic disk device. As a result, the undulations of the data tracks drawn on the pre-servo write disk all hinder the tracking operation of the magnetic head.

Therefore, measures have been taken to cancel the deviation of the rotation synchronization component by introducing the learning control technique.
As described above, the deviation of the data track drawn on the pre-servo write disk from the ideal spiral curve is
Compared with the conventional push pin method, the equipment used is not a mass-produced product and is advantageous in that its performance can be improved. Therefore, the deviation of the rotation synchronization component can be significantly reduced. Moreover, by using the learning control, it is possible to sufficiently eliminate the tracking error with respect to the deviation of the rotation synchronization component.

However, in order to mount the pre-servo write disk on the spindle hub of the magnetic disk apparatus, the design is such that the outer diameter of the spindle hub and the inner diameter of the center hole of the pre-servo write disk can be inserted even in the worst combination. Must be dimensioned. That is, even if the outer diameter of the spindle hub is finished at the maximum value of the intersection area and the inner diameter of the center hole of the pre-servo write disk is finished at the minimum value of its tolerance area, the outer diameter of the spindle hub is smaller than the inner diameter of the disk center hole. There must be.
In addition, the minimum clearance required to allow the pre-servo write disk to be smoothly inserted into the spindle hub must be taken into consideration.

An actual example in which the machining tolerance of the outer diameter of the spindle hub and the machining tolerance of the inner diameter of the center hole of the pre-servo write disk are taken into consideration in terms of productivity and cost will be specifically described. When the gap between the two becomes maximum, that is, the outer diameter of the spindle hub is finished with the minimum value of its tolerance range,
When the inner diameter of the center hole of the pre-servo write disk is finished with the maximum value of its tolerance range, the gap between them is 40 μm in radius.
It will be about. In other words, the rotational synchronization primary component of the data track due to the misalignment of the rotation center axis due to the fitting gap between the two, that is, the misalignment, may be up to 40 μm. For example
In the case of 60,000 TPI (Track Per Inch), since the track pitch is about 0.42 μm, the deviation of 40 μm is about 94 tracks. The eccentricity suppression characteristic of the rotation-synchronous first-order component when learning control is not performed is about -40 dB (1/100). When the deviation of 40 μm occurs, the position error becomes 94% without learning control. The general specification of this position error is
Since it is about 8% or less, in this case, it is necessary to take measures such as learning control to reduce the position error.

However, in reality, it is impossible to make the rotation-synchronous first-order component zero by using learning control. This is because the learning control repeatedly detects the position error and inputs a current to the actuator to make the position error zero.
The actuator outputs in the form of displacement. If there is an unstable factor in the output response characteristic of the actuator, the displacement deviates from the expected displacement. Specifically, this is an unstable factor in which the friction of the bearing is particularly large. The current input waveform to the actuator for canceling the deviation of the rotation-synchronous first-order component becomes a sine waveform when it is considered as a temporal change,
The displacement speed of the actuator also changes in a sinusoidal waveform. That is, the friction of the bearing is unstable and lacks regularity when the displacement speed is close to 0 or when the displacement speed changes from positive to negative or from negative to positive. As a result, the output response characteristic of the actuator becomes unstable, and a slight deviation from the expected displacement occurs.

Further, the displacement operation of the actuator is not limited to learning control, and a minute displacement operation for suppressing a position error due to a disturbance such as non-rotational synchronous shake, vibration, or shock is repeatedly performed. These displacement operations constantly change with time. When these disturbances are applied, it is difficult to analyze and extract only the steady rotation-synchronous shake for learning control without error. Wrong control will be added by this analysis / extraction error,
It causes a position error. It can be said that the position error due to the learning control is larger as the control amount of the learning control is larger.
Further, if the amount of movement of the actuator following the data track by control is large, power consumption also increases, and this increase in power consumption is a serious problem especially in magnetic disk devices for portable equipment applications.

Therefore, the displacement control of the actuator for the extremely large deviation of the data track should not rely only on the learning control, but the efforts to reduce the deviation of the data track itself and the improvement of the eccentricity suppressing characteristic of the magnetic disk are also continued. Will be needed. When incorporating a magnetic disk into a spindle hub, a method of incorporating a magnetic disk medium into a magnetic disk device is a special method for reducing misalignment caused by the difference between the outer diameter of the spindle hub and the inner diameter of the center hole of the magnetic disk. Kaihei 9-320002
It is disclosed in the publication.

Means for reducing this misalignment will be briefly described with reference to FIG. FIG. 17 is a plan view showing a method of incorporating a magnetic disk medium into a conventional magnetic disk device disclosed in Japanese Patent Laid-Open No. 9-320002. Of FIG.
(a) shows the mounting state of the magnetic disk on the spindle hub of the STW, and (b) shows the mounting state of the magnetic disk on the spindle hub of the magnetic disk device. In FIGS. 17A and 17B, the STW used during servo write
The spindle hub 29 and the spindle hub 2 of the magnetic disk device are designed to have the same outer diameter. A reference marker 32 is provided on a part of the medium surface of the magnetic disk 1.
Then, the position of the reference marker 32 is recognized by an optical sensor or the like, and the magnetic disk 1 is mounted on the spindle hub 29 of the STW by abutting the position of the reference marker 32 as a reference (FIG. 17A). Similarly, the magnetic disk 1 is incorporated into the spindle hub 2 of the magnetic disk device ((b) of FIG. 17).

Thus, when the magnetic disk 1 is assembled into the STW and the magnetic disk device, the inner diameter side end of the center hole of the magnetic disk 1 and the outer peripheral side ends of the spindle hubs 2 and 29 are butted against each other at the same position. By incorporating, the rotation center 30 of the magnetic disk 1 at the time of servo writing and the rotation center 3 of the magnetic disk 1 at the time of incorporation in the magnetic disk device
The misalignment with 0 is within the outer diameter dimension machining tolerance range of each spindle hub 2, 29. With this method, the influence of the dimensional tolerance of the magnetic disk 1 can be canceled, but the influence of the dimensional tolerance of the respective spindle hubs 2 and 29 cannot be eliminated. As described above, the STW spindle hub 2 which is a production facility can have a very high dimensional accuracy, but the diameter of the spindle hub 29 of the magnetic disk device, which is a mass-produced product, has a
A tolerance width of about 10 to 20 μm is required. Therefore, the influence of the dimensional tolerance of the spindle hub 29 is at least 5 to 5.
A misalignment of about 10 μm occurs.

Further, in this method, a reference marker is attached to the magnetic disk in order to make the inner diameter side end of the magnetic disk abut against the outer peripheral side end of each spindle hub at the same position during servo writing and assembling into the magnetic disk device. It is necessary to provide and to detect the reference marker. That is, it is necessary to provide a step of attaching a reference marker after the magnetic disk manufacturing process or after the magnetic disk is manufactured, and a step of detecting the reference marker when the magnetic disk is mounted on each spindle hub. Leads to. Further, as shown in FIG. 12, the central axes 2d and 29d of the spindle hubs 2 and 29 and the central axis 30 of the magnetic disk 1 are deviated from each other in principle.
Unbalance always occurs when the magnetic disk rotates.

An object of the present invention is to coaxially correct the misalignment between the spindle hub and the magnetic disk without changing the outer diameter machining tolerance of the spindle hub, the inner diameter machining tolerance of the magnetic disk, and the insertion gap dimension between them. It is to provide a magnetic disk device that can be mounted. This allows
It is possible to provide a magnetic disk device suitable for using a pre-servo write disk created by a single-plate servo write method or a magnetic transfer method. Further, by mounting a magnetic disk coaxially on the spindle hub, it is intended to provide a magnetic disk device capable of realizing data recording / reproducing with a high track pitch without rotation-synchronous shake.

[0034]

SUMMARY OF THE INVENTION A magnetic disk device according to the present invention is a disk insertion cylinder of a magnetic disk for information recording / reproducing having a chamfered portion in a center hole, and a slanted guide portion for inserting into the center hole. A spindle hub having a flange portion on which the magnetic disk is to be mounted, a first inclined surface facing the chamfered portion of the center hole of the magnetic disk, and a first inclined surface facing the inclined surface of the guide portion of the spindle hub. An inclined surface, and an aligning member which is fitted into the center hole of the magnetic disk and placed thereon; a clamp for integrally fixing the magnetic disk and the aligning member to the spindle hub; It comprises means for pressing the clamp to fasten it to the spindle hub, and a spindle motor for rotating the spindle hub.

According to this structure, when the magnetic disk having the aligning member fitted therein is inserted into the spindle hub and a clamping force is applied to the aligning member, the chamfered portion of the magnetic disk and the aligning member are The misalignment between the magnetic disk and the aligning member is corrected by the reaction force acting between the first inclined surface and the guide portion of the spindle hub and the second inclined surface of the aligning member. It can be mounted coaxially on the spindle hub. In this state, the clamp can be pressed to integrally fix the magnetic disk to the spindle hub. As a result, the outer diameter machining tolerance of the spindle hub, the inner diameter machining tolerance of the magnetic disk, and the appropriate insertion gap dimension between the two are not particularly strict, and the misalignment between the spindle hub and the magnetic disk is corrected and mounted coaxially. It is possible to provide a magnetic disk device that can be rotated without rotation-synchronous shake.

According to another aspect of the present invention, there is provided a magnetic disk device having a disk inserting cylindrical portion for inserting into the central hole of an information recording / reproducing magnetic disk having a chamfered portion in the central hole in addition to the above characteristics. A spindle hub having a flange portion on which the magnetic disk is to be mounted; a first inclined surface facing the chamfered portion of the center hole of the magnetic disk; and an intersection of the disk insertion cylindrical portion and the flange portion of the spindle hub. A second inclined surface that faces the inclined surface provided in the region, and is fitted into the center hole of the magnetic disk and placed on the flange portion, the magnetic disk, and the centering member. A clamp for integrally fixing a member to the spindle hub, means for pressing the clamp to fasten the spindle hub, and a spin for rotating the spindle hub. It has a motor.

According to this structure, when the magnetic disk is inserted into the aligning member placed on the flange portion of the spindle hub and a clamping force is applied to the magnetic disk, the chamfered portion of the magnetic disk and the aligning member are adjusted. A second inclined surface facing the first inclined surface of the core member and an inclined surface provided in the intersection area of the disk insertion cylindrical portion and the flange portion of the spindle hub.
By the reaction force acting between each of the inclined surfaces, the misalignment between the magnetic disk and the aligning member can be corrected, and the magnetic disk can be coaxially mounted on the spindle hub. In this state, the clamp can be pressed to integrally fix the magnetic disk to the spindle hub. As a result, without particularly tightening the outer diameter machining tolerance of the spindle hub, the inner diameter machining tolerance of the magnetic disk, and the appropriate insertion gap dimension between them,
It is possible to provide a magnetic disk device capable of correcting misalignment between the spindle hub and the magnetic disk and coaxially mounting them to eliminate rotation-synchronous runout and rotate.

A magnetic disk device according to still another aspect of the present invention is, in addition to the above characteristics, a disk insertion cylindrical portion for inserting into a central hole of an information recording / reproducing magnetic disk having a chamfered portion in the central hole. A spindle hub having a flange portion for mounting the magnetic disk, a first inclined surface facing the chamfered portion of the center hole of the magnetic disk, and an inner surface facing the outer peripheral side surface of the disk insertion cylindrical portion of the spindle hub. An elastic member is provided on a peripheral portion, and an inner peripheral diameter of the elastic member in an unloaded state is equal to or smaller than an outer peripheral diameter of the spindle hub cylindrical portion, and the elastic member is fitted into a central hole of the magnetic disk and placed on the flange portion. Aligning member,
A clamp for integrally fixing the magnetic disk and the aligning member to the spindle hub, means for pressing the clamp to fasten it to the spindle hub, and a spindle motor for rotating the spindle hub are provided.

According to this structure, when the magnetic disk in which the aligning member is fitted is inserted into the disk insertion cylindrical portion of the spindle hub and placed on the flange portion, and the clamping force is applied to the magnetic disk, By the chamfered portion of the magnetic disk, the first inclined surface of the alignment member, and the reaction force acting between the disk insertion cylindrical portion of the spindle hub and the elastic member of the alignment member, the magnetic disk and the alignment member are adjusted. It can be mounted coaxially on the spindle hub by correcting the misalignment with the core member. In this state, the clamp can be pressed to integrally fix the magnetic disk to the spindle hub. As a result, the outer diameter machining tolerance of the spindle hub, the inner diameter machining tolerance of the magnetic disk, and the appropriate insertion gap dimension between the two are not particularly strict, and the misalignment between the spindle hub and the magnetic disk is corrected and mounted coaxially. It is possible to provide a magnetic disk device that can be rotated without rotation-synchronous shake. In particular, according to this configuration, a plurality of magnetic disks, into which the centering members have been previously fitted, are stacked and inserted into the disk insertion cylindrical portion of the spindle hub, and the centering members can be used as spacers for assembly. Therefore, it is suitable for a magnetic disk device in which a plurality of magnetic disks are stacked and mounted on a spindle hub.

[0040]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of a magnetic disk device of the present invention will be described below with reference to the accompanying drawings. In the following description of each embodiment, in order to clarify and briefly describe the characteristic part of the present invention, the clamp structure part of the magnetic disk to the spindle motor in the magnetic disk device will be mainly described.

The spindle motor used in the magnetic disk device will be described as an inner rotor type in which a rotor having a magnet and a yoke is arranged on the inner circumference of a stator having a coil wound around an iron core. However, the present invention is not limited to this, and can also be applied to outer rotor type, surface facing type, and other types of spindle motors. The spindle motor in the magnetic disk device of the embodiment will be described as a shaft rotation type in which the outer ring of the motor bearing is fixed to the base and the inner ring and the motor shaft rotate.
The present invention is not limited to this, and can be applied to outer ring rotation and other types of spindle motors.

<< Embodiment 1 >> FIG. 1 is a partial cross-sectional view showing a structure for clamping a magnetic disk to a spindle motor in a magnetic disk apparatus according to Embodiment 1 of the present invention. In FIG. 1, a spindle motor 5 used in the magnetic disk device of the first embodiment is an inner rotor type in which a rotor 10 having a magnet 11 and a yoke 12 is arranged on an inner peripheral portion of a stator 13 in which a coil 15 is wound around an iron core 14. It is the spindle motor of. In this spindle motor 5, an outer ring 16b of a motor bearing 16 is fixed to a base 106, and a motor shaft 17 for rotating an inner ring 16a and a spindle hub 2 for mounting a magnetic disk 1 are integrally formed on a rotor 10. It is a type.

The magnetic disk 1 is placed on the flange portion 2c of the spindle hub 2, and the center hole 1 of the magnetic disk 1 is placed.
A centering member 6 is placed on a, and the magnetic disk 1 and the centering member 6 are integrally fixed to a spindle hub 2 by a screw 4 via a clamp 3. The process of mounting the magnetic disk 1 on the spindle hub 2 will be described in detail below.
First, the center hole 1a of the magnetic disk 1 is inserted into the disk insertion cylindrical portion 2a of the spindle hub 2, and the magnetic disk 1 is placed on the flange portion 2c. After that, the centering member 6 is placed on the chamfered portion 1b of the inner peripheral portion of the center hole 1a of the magnetic disk 1 in such a manner that it is inserted into the disk insertion cylindrical portion 2a of the spindle hub 2. Further, the clamp 3 is placed on the centering member 6, the screw 4 is inserted into the central hole of the clamp 3, and then the clamp 3 is fastened to the clamp screw hole 2e of the spindle hub 2.
Thus, the magnetic disk 1 and the centering member 6 are sandwiched between the flange portion 2c of the spindle hub 2 and fixed to the spindle hub 2.

FIG. 2 is a sectional view showing a state before the magnetic disk 1 is fixed to the spindle hub 2 by the clamp 3 in the magnetic disk device of the first embodiment. As shown in FIG. 2, in this state, the central axis 2d of the spindle hub 2 and the central axis 1c of the magnetic disk 1 do not necessarily coincide. Specifically, for example, the magnetic disk 1 is displaced from the spindle hub 2 in the horizontal direction indicated by the arrow in the figure. Normally, a chamfered portion 1b is formed at the inner peripheral end of the center hole 1a of the magnetic disk 1 coaxially with the center axis 1c. The chamfered portion 1b is provided to serve as a guide when inserting the magnetic disk 1 into the spindle hub 2 and to prevent damage due to collision during handling.
A slanted guide portion 2b is also formed coaxially with the central axis 2d at the tip of the disk insertion cylindrical portion 2a of the spindle hub 2.

On the other hand, the centering member 6 is provided with a first inclined surface 6a and a second inclined surface 6b. Spindle hub 2
The first inclined surface 6a faces the chamfered portion 1b provided at the inner peripheral end of the center hole 1a of the magnetic disk 1 with the magnetic disk 1 and the aligning member 6 placed on the flange portion 2c of the magnetic disk 1. The second inclined surface 6b faces the guide portion 2b provided on the disc insertion cylindrical portion 2a of the spindle hub 2. The elastic member 7 is attached to the first inclined surface 6a facing the chamfered portion 1b of the magnetic disk 1, and the chamfered portion 1
b and the elastic member 7 are in contact with each other. Also, there is a slight gap in the axial direction between the disc pressing portion 6c of the aligning member 6 and the surface of the magnetic disc 1, and the average value of one circumference of this axial gap is the elasticity due to the axial pressing force added later. It is designed to be equal to or greater than the amount of axial compression of the member 7. There is a slight gap between the guide portion 2b of the spindle hub 2 and the second inclined surface 6b, and this gap differs depending on the position on the circumference. The gap is maximum or minimum at the circumferential position in the diameter direction of the magnetic disk 1 which connects the central axis 2d of the spindle hub 2 and the central axis 1c of the magnetic disk 1 on a plan view.

FIG. 3A is a sectional view showing a state in which the magnetic disk 1 is being fixed to the spindle hub 2 by the clamp 3 in the magnetic disk device of the first embodiment. FIG. 3B is an enlarged view for explaining the force generated between the centering member 6 and the spindle hub 2 in the state of FIG. As shown in (a) of FIG. 3, as the screw 4 is tightened in the screw hole 2e of the spindle hub 2, the head 4a of the screw 4 presses the clamp 3 in the axial direction indicated by the arrow in the drawing, The aligning member 6 is pressed in the axial direction by the pressing portion 3c of 3. Here, pressing in the axial direction means displacing the screw 4 in the direction in which the axial pressing force of the screw is generated when the screw 4 is tightened (downward in the drawing). As a result, the aligning member 6 causes the magnetic disk 1 to pass through the elastic member 7.
Of the central axis 1 of the magnetic disk 1 by pressing the chamfered portion 1b of the central hole 1a of the magnetic disk 1 and balancing the reaction force acting between the slant surfaces of the elastic member 7 and the chamfered portion 1b in one round.
Aligning is performed so that c and the center axis of the aligning member 6 coincide with each other.

As the screw 4 is further tightened,
The thickness of the elastic member 7 is reduced by being compressed by the first inclined surface 6a of the aligning member 6 and the chamfered portion 1b. Here, the axial rigidity of the aligning member 6 is selected to be sufficiently larger than the compressive rigidity of the elastic member 7. Therefore, due to the reduction in the thickness of the elastic member 7, the aligning member 6 moves in the axial direction with almost no deformation. When the aligning member 6 moves in the axial direction, first, at the position where the gap between the second inclined surface 6b of the aligning member 6 and the guide portion 2b of the spindle hub 2 is the narrowest, the second inclined surface 6b and the guide portion 2b are formed. Contact with slopes.

As shown in FIG. 3B, when the screw 4 is tightened and the axial pressing force Fa is applied in the state where the second inclined surface 6b and the inclined surface of the guide portion 2b are in contact with each other, the aligning member 6 is moved. A force Fp that causes the second inclined surface 6b to slide along the inclined surface of the guide portion 2b is generated. Here, the force acting vertically on the second inclined surface 6b of the aligning member 6 with respect to the guide portion 2b of the spindle hub 2 is F, and the horizontal component of the force F is F.
Let h. The horizontal component Fh serves as a force to push the aligning member 6 in the horizontal direction, and the aligning member 6 moves the magnetic disk 1 through the elastic member 7 attached to the first inclined surface 6a to the arrow in FIG. Push in the horizontal direction with force F shown in. The horizontal component Fh of this force F is the second inclined surface 6b and the guide portion 2b in one round.
Works only on the parts that are in contact with. That is, it works in a direction in which the central axis 1c of the magnetic disk 1 approaches the central axis 2d of the spindle hub 2. If the horizontal component Fh is larger than the static frictional force, the magnetic disk 1 and the centering member 6 have a direction in which the central axis 1c of the magnetic disk 1 coincides with the central axis 2d of the spindle hub 2, that is, the direction in which the misalignment is corrected. Move to.

Since the static friction coefficient between the second inclined surface 6b and the guide portion 2b is very small because it is line contact or point contact, it is omitted for simplification, and the surface of the magnetic disk 1 and the flange portion 2c are omitted. If the static friction coefficient is μ 2 = 0.2, the static friction force Fm, and the inclination angle of the inclined surface of the spindle hub 2 is θ, the axial force Fa, the force Fp that causes the inclined surface 6b to slide, and the inclined surface 6b are perpendicular to the inclined surface 6b. Horizontal force component F of working force
The following equations (1), (2), and (3) are established between h.

[0050]       Fm = Fa × 0.2 (1)

[0051]       Fp = Fa × cos θ (2)

[0052]       Fh = Fa × sin θ × cos θ (3)

That is, in order to move the magnetic disk 1 and the centering member 6 in the horizontal direction, the following equations (4) and (5) should be established.

[0054]       Fh = Fa × sin θ × cos θ> Fm = Fa × 0.2 (4)

[0055]   Therefore sin θ × cos θ> 0.2 (5)

FIG. 15 shows sin θ × cos with θ as a parameter
The graph of the value of (theta) is shown.

As shown in FIG. 15, if the tilt angle θ is in the range of 12 ° to 78 °, the above equation (5) is established, and the misalignment can be corrected by moving the magnetic disk in the horizontal direction. . Normally θ is designed to be 45 °, and the horizontal component F
Since h is about 2.5 times the static friction force Fm, it can be said that there is a sufficient margin to correct the misalignment.

FIG. 4 is a sectional view showing a state in which the magnetic disk 1 is fixed to the spindle hub 2 by the clamp 3 in the magnetic disk device of the first embodiment. As shown in FIG.
If the screw 4 is further tightened and an axial pressing force Fa is applied,
Eventually, the second inclined surface 6b of the centering member 6 makes uniform surface contact or line contact with the guide portion 2b over the entire circumference. At this time, the central axis 1c of the magnetic disk 1 and the central axis 2d of the spindle hub 2 are aligned, and the horizontal component Fh is balanced over the entire circumference. As a result, the central axis 1 of the magnetic disk 1
The state where c and the central axis 2d of the spindle hub 2 coincide with each other is maintained.

Also in the axial direction, since the guide portion 2b supports the second inclined surface 6b of the aligning member 6 over the entire circumference, the aligning member 6 does not move in the axial direction. As described above, the disc pressing portion 6 of the centering member 6 before the axial pressing force is applied.
The circumferential average value of the axial gap between c and the surface of the magnetic disk 1 is equal to or more than the axial compression amount of the elastic member 7 due to the axial pressing force applied. Therefore, even at this time, the disc pressing portion 6c
There is a gap between the magnetic disk 1 and the surface of the magnetic disk 1. Even if they are in contact with each other, the force with which the disk pressing portion 6c presses the magnetic disk 1 is very small as compared with the clamping force required to fix the magnetic disk 1 to the spindle hub 2, so as to correct the misalignment. The movement of the centering member 6 and the magnetic disk 1 is not prevented.

When the screw 4 is further tightened and a clamping force is applied, elastic deformation occurs in the concave portion 6d which is set to have smaller rigidity than the other portions in the aligning member, and the concave portion 6 is formed.
The outer peripheral portion of the spindle hub 2 is displaced in the axial direction from d, the disk pressing portion 6c eventually contacts the surface of the magnetic disk 1, and the magnetic disk 1 is pressed against the flange portion 2c.
And rotatably fixed together with.

According to the magnetic disk drive of the first embodiment,
By using the aligning member 6, the working tolerance of the magnetic disk 1 and the spindle hub 2 and the gap for easily inserting the magnetic disk 1 are not particularly severe,
The magnetic disk 1 can be coaxially placed and fixed on the spindle hub 2 simply by performing a normal clamping operation. As a result, the pre-servo write disk can be easily mounted on the mass-produced magnetic disk device without misalignment, so that it is possible to provide a magnetic disk device capable of rotating the magnetic disk without rotation-synchronous runout. In the magnetic disk device of the first embodiment, the screw 4 is tightened to obtain the axial component force Fa. However, before or after the clamp 3 is placed, the axial component force Fa is set using a jig or the like. May be loaded for alignment.

<Embodiment 2> FIG. 5 is a partial sectional view showing a clamp structure of a magnetic disk to a spindle motor in a magnetic disk apparatus according to Embodiment 2 of the present invention. FIG. 5 shows a state after the magnetic disk is clamped in the magnetic disk device of the second embodiment. The structure for clamping the magnetic disk to the spindle motor in the magnetic disk device of the second embodiment differs from that of the first embodiment only in the configuration of the aligning member. Therefore, the portions corresponding to those of the first embodiment are designated by the same reference numerals and the duplicated description will be omitted. Figure 5
As shown in FIG. 5, the elastic member 71 is attached to the inclined surface 61b of the aligning member 61 of the magnetic disk device of the second embodiment, which is opposed to the guide portion 2b of the spindle hub 2.

When the screw 4 is tightened in the screw hole 2e of the spindle hub 2 and an axial pressing force is applied to the clamp 3, the aligning member 61 is pressed in the axial direction. As a result, the aligning member 61 presses the guide portion 2b of the spindle hub 2 via the elastic member 71, and the balance of the reaction forces acting between the inclined surfaces of the elastic member 71 and the guide portion 2b in one round is caused by the balance of the spindle hub 2 Center axis 2d and aligning member 61
It is corrected so that the central axis of the may coincide. Screw 4
As the screw is tightened, the elastic member 7 is compressed by the second inclined surface 61b of the aligning member 61 and the guide portion 2b.
The thickness of 1 decreases. Here, the axial rigidity of the aligning member 61 is sufficiently higher than the compressive rigidity of the elastic member 71, so that the thickness of the elastic member 71 is mainly reduced, and the aligning member 61 moves in the axial direction with almost no deformation. When the aligning member 61 moves in the axial direction, first, at the position where the gap between the first inclined surface 61a of the aligning member 61 and the chamfered portion 1a of the magnetic disk 1 is the narrowest, the first inclined surface 61a and the chamfered portion 1a are first. Contact with slopes.

Then, as in the first embodiment, as the screw 4 is tightened, the first inclined surface 61a of the aligning member 61 and the inclined surface of the chamfered portion 1a of the magnetic disk 1 come into contact with each other, so that the magnetic disk 1 becomes horizontal. The center axis 2d of the spindle hub 2 and the center axis 1c of the magnetic disk 1 can be aligned with each other by moving in the direction to correct the misalignment.

<Third Embodiment> FIG. 6 is a partial sectional view showing a clamp structure of a magnetic disk to a spindle motor in a magnetic disk device according to a third embodiment of the present invention. FIG. 6 shows a state after the magnetic disk is clamped in the magnetic disk device of the third embodiment. The structure for clamping the magnetic disk to the spindle motor in the magnetic disk device of the third embodiment differs from that of the first embodiment only in the configuration of the aligning member. Therefore, the portions corresponding to those of the first embodiment are designated by the same reference numerals and the duplicated description will be omitted. As shown in FIG. 6, the centering member 62 in the magnetic disk device of the third embodiment is formed of an elastic material having a low friction coefficient, such as fluorine resin. The average value of the circumference of the axial gap between the disk pressing portion 62c provided on the aligning member 62 and the magnetic disk 1 before the axial pressing force is applied to the magnetic disk 1 of the aligning member 62c by the axial pressing force is applied. It is set to be equal to or greater than the relative axial movement amount.

When the axial pressing force of the clamp 3 generated by tightening the screw 4 is applied to the aligning member 62 from the pressing portion 3c, the aligning member 62 made of an elastic material is used.
Axial deformation occurs near the disk pressing portion 62c.
However, since the one-round average value of the axial gap between the disk pressing portion 62c and the magnetic disk 1 is set to be equal to or more than the relative axial movement amount of the aligning member 62 with respect to the magnetic disk 1 due to the axial pressing force applied, the disk pressing The portion 62c does not press the magnetic disk 1 against the flange 2c and hinder the movement of the aligning member 62 and the magnetic disk 1 for correcting the misalignment. After the misalignment is corrected, the disk pressing portion 62c presses the magnetic disk 1 against the flange portion 2c and integrally rotatably fixes it to the spindle hub 2. Example 3
According to this magnetic disk device, the elastic members 7 and 71, which are required in the first and second embodiments, are unnecessary.

[Fourth Embodiment] FIG. 7 is a partial sectional view showing a clamp structure of a magnetic disk to a spindle motor in a magnetic disk device according to a fourth embodiment of the present invention. FIG. 7 shows a state after the magnetic disk is clamped in the magnetic disk device of the fourth embodiment. The structure for clamping the magnetic disk to the spindle motor in the magnetic disk device of the fourth embodiment differs from that of the first embodiment only in the configuration of the aligning member. Therefore, the portions corresponding to those of the first embodiment are designated by the same reference numerals and the duplicated description will be omitted. Figure 7
As shown in FIG. 5, an aligning ring 31d is bonded to the lower side of the clamp 31 in the magnetic disk device of the fourth embodiment. The alignment ring 31d is provided on the first inclined surface 31a facing the chamfered portion 1b provided on the inner peripheral end of the center hole 1a of the magnetic disk 1 and on the disk insertion cylindrical portion 2a of the spindle hub 2. It has a second inclined surface 31b facing the guide portion 2b.

In the magnetic disk device of the fourth embodiment, when the aligning ring 31d having the inclined surface 31a and the inclined surface 31b is integrally formed on the clamp 31, the clamp 31 is the same as that of the first to third embodiments. However, the function of the centering member is also shown in FIGS. Therefore, according to this magnetic disk device, the aligning members 6 and 61 used in the first and second embodiments are unnecessary. In addition, the centering ring 3 corresponds to the elastic member adhered to the centering member in the previous embodiment.
The first inclined surface 31a or the second inclined surface 31b of 1d can be provided in the same manner as in the preceding embodiments.

<Fifth Embodiment> FIG. 8 is a partial cross-sectional view showing a structure for clamping a magnetic disk to a spindle motor in a magnetic disk device according to a fifth embodiment of the present invention. FIG. 8 shows a state after the magnetic disk is clamped in the magnetic disk device of the fifth embodiment. The structure for clamping the magnetic disk to the spindle motor in the magnetic disk device of the fifth embodiment differs from that of the first embodiment only in the shape of the inclined surface of the guide portion of the spindle hub. Therefore, the portions corresponding to those of the first embodiment are designated by the same reference numerals and the duplicated description will be omitted. As shown in FIG. 8, the inclined surface of the guide portion 21b provided at the tip of the disk insertion cylindrical portion 21a of the spindle hub 21 in the magnetic disk device of the fifth embodiment is a curved surface.

According to the magnetic disk device of the fifth embodiment, by making the inclined surface of the guide portion 21b a curved surface, it is possible to reduce the contact area of the aligning member 6 with the second inclined surface 6b and reduce the frictional force. it can. In particular, when the guide portion 21b comes into contact with the elastic member 7 attached to the second inclined surface 6b of the aligning member 6, there is a tendency for surface contact, so that the guide portion 21b is formed into a curved surface to reduce the contact area and the friction force. It is possible to easily correct the misalignment by reducing.

<Embodiment 6> FIG. 9 is a partial sectional view showing a clamp structure of a magnetic disk to a spindle motor in a magnetic disk apparatus according to Embodiment 6 of the present invention. FIG. 9 shows a state after the magnetic disk is clamped in the magnetic disk device of the sixth embodiment. The magnetic disk clamping structure for the spindle motor in the magnetic disk device of the sixth embodiment differs from that of the first embodiment only in the shapes of the first inclined surface and the second inclined surface of the aligning member. is there. Therefore, the portions corresponding to those of the first embodiment are designated by the same reference numerals and the duplicated description will be omitted. As shown in FIG. 9, in the aligning member 63 in the magnetic disk device of the sixth embodiment of the present invention, the first inclined surface 63a and the second inclined surface 63b are connected to each other to form one curved surface 63d. ing.

According to the magnetic disk device of the sixth embodiment, the guide portion is formed by forming one curved surface 63d in which the first inclined surface 63a and the second inclined surface 63b provided on the aligning member 63 are connected. 2b and the chamfered portion 1b of the magnetic disk 1 and the curved surface 63d of the aligning member 63 can be reduced in contact area to reduce the frictional force. In particular, when the chamfered portion 1b and the guide portion 2b come into contact with the elastic member 7 attached to the curved surface 63d, there is a tendency for surface contact, so that the curved surface is used to reduce the contact area and reduce the frictional force to correct misalignment. Can be done easily. Further, since the first curved surface 63d is formed by connecting the first inclined surface 63a and the second inclined surface 63b, the centering member 63 can be easily processed.

In the above embodiment, the first inclined surface 63a and the second inclined surface 63a
The alignment member having one curved surface 63d connected to the inclined surface 63b has been described, but any one of the first inclined surface 63a and the second inclined surface 63b, or each of them has an independent curved surface. It may be a core member.

<< Embodiment 7 >> FIG. 10 shows a seventh embodiment of the present invention.
6 is a cross-sectional view showing a state before fixing the magnetic disk 1 to the spindle hub 22 by the clamp 3 in the magnetic disk device of FIG. The structure for clamping the magnetic disk to the spindle motor in the magnetic disk device of the seventh embodiment differs from that of the first embodiment only in the configurations of the spindle hub and the aligning member. Therefore, the portions corresponding to those of the first embodiment are designated by the same reference numerals and the duplicated description will be omitted.

As shown in FIG. 10, on the spindle hub 22 of the magnetic disk device of the seventh embodiment, the magnetic disk 1 is placed via the disk inserting cylindrical portion 22a into which the magnetic disk 1 is inserted and the aligning member 64. Flange part 22
c and an inclined surface 22f provided at the intersection of the disc insertion cylindrical portion 22a and the flange portion 22c are formed coaxially with respect to the central axis. The aligning member 64 includes
A second inclined surface 64b that faces the inclined surface 22f of the spindle hub 22 and a first inclined surface 64a that faces the chamfered portion 1b of the magnetic disk 1 are provided coaxially with the central axis. The aligning member 64 includes the ring-shaped shim 8, the elastic member 72 provided on the inner peripheral surface of the ring-shaped shim 8, and the flange portion 2.
It integrally has an elastic body 9 provided on the bottom surface on the side facing 2c. The first inclined surface 64a is formed on the outer periphery of the elastic member 72, and the second inclined surface 64b is formed on the lower side of the inner periphery of the ring-shaped shim 8.

A method of mounting the magnetic disk 1 in the magnetic disk device of the seventh embodiment will be described with reference to FIG. First, the center hole 64d of the aligning member 64 and the center hole 1a of the magnetic disk 1 are inserted into the disk insertion cylindrical portion 22a of the spindle hub 22, and the magnetic disk 1 is placed on the flange portion 22c with the aligning member 64 interposed therebetween. Place it. At this time, the first inclined surface 64a of the aligning member 64 faces the chamfered portion 1b of the magnetic disk 1, and the elastic body 9 is attached to the flange portion 2c.
To face. Place the clamp 3 on the magnetic disk 1,
Insert the screw 4 into the clamp center hole. In this state, the central axis 22d of the spindle hub 22 and the central axis 1c of the magnetic disk 1 have not yet coincided with each other. Specifically, the magnetic disk 1 is horizontally displaced from the spindle hub 22.

At this time, the first inclined surface 64 of the aligning member 64
a and the chamfered portion 1b of the magnetic disk 1 are in surface contact or line contact over substantially the entire circumference. There is a gap between the bottom surface of the magnetic disk 1 and the surface of the ring-shaped shim 8 facing the bottom surface. Further, the elastic body 9 provided on the lower surface of the aligning member 64 and the flange portion 22c of the spindle hub 22 are in surface contact with each other. A slight gap exists between the inclined surface 22f of the spindle hub 22 and the second inclined surface 6b of the aligning member 64, and this gap varies depending on the position on the circumference. This gap is maximum or minimum at the circumferential position in the diameter direction of the magnetic disk 1 which connects the central axis 2d of the spindle hub 2 and the central axis 1c of the magnetic disk 1 on a plan view.

FIG. 11A is a sectional view showing the process of fixing the magnetic disk 1 to the spindle hub 22 by the clamp 3 in the magnetic disk device of the seventh embodiment. FIG. 11B is an enlarged view for explaining the force generated between the aligning member 64 and the spindle hub 22 in the state of FIG. 11A. As shown in FIG. 11A, the screw 4 is tightened in the screw hole 22e of the spindle hub 22.
Then, the pressing portion 3c of the clamp 3 causes the pressing portion 3c of FIG.
The magnetic disk 1 to which the axial force Fa indicated by the arrow is applied presses the first inclined surface 64a on the outer periphery of the elastic member 72 in the aligning member 64 in the chamfered portion 1b. As a result, the horizontal component of the reaction force from the first inclined surface 64a of the aligning member 64 is corrected so that the center axes of both the aligning member 64 and the magnetic disk 1 coincide with each other, and both are in surface contact over the entire circumference. To do. The aligning member 64 is formed by integrally bonding the elastic member 72 and the elastic body 9 to the ring-shaped shim 8 or by injection molding. Due to the axial force Fa, the first inclined surface 64a of the aligning member 64 is pressed in the axial direction, the magnetic disk 1 moves in the axial direction, and the back surface thereof makes surface contact with the front surface of the ring-shaped shim 8.

In the unaligned state of FIG. 11A, there is a gap between the second inclined surface 64b of the aligning member 64 and the inclined surface 22f of the spindle hub 22, which varies depending on the circumferential position. However, the elastic body 9 is axially compressed by the axial force from the clamp 3, and the aligning member 64 and the magnetic disk 1 are
And move axially. As a result, the second centering member 64
The gap between the inclined surface 64b (located on the inner peripheral lower surface of the ring-shaped shim 8) and the inclined surface 22f of the spindle hub 22 is reduced. The position where the gap is the smallest, that is, the central axis 22d of the spindle hub 2 and the central axis 1 of the magnetic disk 1
The second inclined surface 64b of the aligning member 64 and the inclined surface 22f of the spindle hub 22 are in contact with each other at a position in the diametrical direction of the magnetic disk 1 that connects with c on the plan view.

As shown in FIG. 11 (b), the axial pressing force applied to the contact portion between the second inclined surface 64b of the aligning member 64 and the inclined surface 22f of the spindle hub 22 via the magnetic disk 1. Due to the horizontal component Fh of the force applied to the aligning member 64 by the reaction force F of Fa, the aligning member 64 receives a horizontal force for correcting the misalignment with respect to the central axis 2d of the spindle hub 22. An elastic body 9 is placed on the lower surface of the ring-shaped shim 8 of the aligning member 64 and the upper surface of the flange portion 22c of the spindle hub 22 so as to make surface contact with the latter. The rigidity of the elastic body 9 in the shearing direction (horizontal direction here) is small. Therefore, even when the horizontal component Fh is smaller than the static frictional force on the contact surface between the elastic body 9 and the flange portion 22c, the aligning member 64 can move in the direction for correcting the misalignment with respect to the central axis 22d of the spindle hub 22. is there. That is, even if slippage does not occur on the contact surface between the elastic body 9 and the flange portion 2c, the elastic body 9 undergoes shear deformation and the aligning member 64 and the magnetic disk 1 are integrated with each other with respect to the center axis 22d of the spindle hub 22. Move in the direction to correct the deviation.

FIG. 12 is a sectional view showing a state after the magnetic disk 1 is fixed to the spindle hub 22 by the clamp 3 in the magnetic disk device of the seventh embodiment. As shown in FIG. 12, when the screw 4 is further tightened to apply a clamping force, the second inclined surface 64b of the aligning member 64 eventually comes into surface contact with the inclined surface 22f of the spindle hub 22 over the entire circumference. At this point, the magnetic disk 1 has already been recorded as described above.
Since the centering member 64 is coaxially integrated with the centering member 64, the center axis 1c of the magnetic disk 1 and the center axis 22 of the spindle hub 22 are
matches d. After that, since the horizontal components of the reaction force from the second inclined surface 64b to the inclined surface 22f are balanced over the entire circumference, the magnetic disk 1 and the spindle hub 2
The state in which the central axes 1c and 22d of 2 coincide with each other can be maintained. Even if you tighten the screw 4 and apply clamping force,
The aligning member 64 does not move in the axial direction. Further, the ring-shaped shim 8 made of a highly rigid material such as stainless steel does not deform. Therefore, the magnetic disk 1 and the aligning member 64
Is pressed against the inclined surface 22f of the spindle hub 22 and the flange portion 22c, and is rotatably fixed integrally with the spindle hub 22.

According to the magnetic disk drive of the seventh embodiment,
By using the aligning member 64, it is possible to perform a normal clamping operation without making the machining tolerance of the magnetic disk 1 and the spindle hub 22 and a gap for inserting the magnetic disk 1 particularly strict. Can be mounted and fixed coaxially on the spindle hub 22.
As a result, the pre-servo write disk can be easily mounted on the mass-produced magnetic disk device without misalignment. In this way, it is possible to provide a magnetic disk device capable of rotating a magnetic disk without causing rotational synchronization shake due to misalignment. In the magnetic disk device of Example 7, the screw 4 is tightened to obtain the axial force Fa.
Before or after the clamp 3 is placed, a jig or the like may be used to apply the axial force Fa to perform the alignment.

<< Embodiment 8 >> FIG. 13 shows an embodiment 8 of the present invention.
4 is a cross-sectional view showing a state in which the magnetic disk 1 is fixed to the spindle hub 23 by the clamp 3 in the magnetic disk device of FIG. The structure for clamping the magnetic disk to the spindle motor in the magnetic disk device of the eighth embodiment is the same as the first embodiment.
Only the configurations of the spindle hub and the aligning member are different. Therefore, the portions corresponding to those of the first embodiment are designated by the same reference numerals and the duplicated description will be omitted. As shown in FIG. 13, in the spindle hub 23 of the magnetic disk device of the eighth embodiment, a disk insertion cylindrical portion 23 a into which the magnetic disk 1 is inserted via a centering member 65, and a magnetic disk via the centering member 65. Flange part 23 for mounting 1
c is provided. The aligning member 65 has a plate-like ring-shaped shim 85 formed of a high-rigidity material such as stainless steel, and an elastic member 75 provided on the inner peripheral portion thereof.

That is, the inner surface of the center hole of the aligning member 65 facing the outer periphery of the disk inserting cylindrical portion 23a of the spindle hub 23 is formed by the elastic member 75. The inner surface 75 of the elastic member 75 in the unloaded state of the elastic member 75
The inner peripheral diameter of a is designed to be slightly smaller than the outer peripheral diameter of the disc insertion cylindrical portion 23a so that it can be easily press-fitted into the disc insertion cylindrical portion 23a of the spindle hub 23. Further, an inclined surface 65 a facing the chamfered portion 1 b at the inner peripheral end of the center hole 1 a of the magnetic disk 1 is also formed by the elastic member 75.

A method of mounting the magnetic disk 1 in the magnetic disk device of the eighth embodiment will be described with reference to FIG. The center hole 75a of the centering member 65 fitted in the center hole 1a of the magnetic disk 1 is press-fitted onto the outer periphery of the disk insertion cylindrical portion 23a of the spindle hub 23, and the magnetic disk 1 is provided with the centering member 65 in between. 23c. At this time, the front and back directions of the aligning member 65 are determined so that the inclined surface 65a of the aligning member 65 faces the chamfered portion 1b of the magnetic disk 1. The center hole 75a of the aligning member 65 and the inclined surface 65a are integrally formed by the elastic member 75, and are coaxially formed. The magnetic disk 1 is placed substantially coaxially with the inclined surface 65a of the aligning member 65 that faces and contacts the chamfered portion 1b.
Bottom surface of the ring and the ring-shaped shim 8 of the aligning member 65 facing the bottom surface
There is a gap between the surface of No. 5 and the surface of No. 5. The spindle hub 23 and the aligning member 65 are coaxially assembled by elastic fitting of the elastic member 75 of the aligning member 65 and the disk insertion cylindrical portion 23a of the spindle hub 23 by press fitting.

Thereafter, the clamp 3 is placed on the magnetic disk 1, the screw 4 is inserted into the clamp center hole, and is fastened to the clamp screw hole 23e of the spindle hub 23. The magnetic disk 1 to which the axial force is applied by the pressing portion 3c of the clamp 3 by the fastening of the screw 4 presses the inclined surface 65a of the aligning member 65 in the axial direction indicated by the arrow in FIG. 9 in the chamfered portion 1b. . The magnetic disk 1 and the centering member 65 are coaxially arranged by the component force in the horizontal direction generated by the pressing between the chamfered portion 1b of the magnetic disk 1 and the inclined surface 65a of the centering member 65. As described above, since the spindle hub 23 and the centering member 65 are coaxially assembled, the central axis 1c of the magnetic disk 1 is coaxial with the central axis 23d of the spindle hub 23. Since the inclined surface 65a of the aligning member is formed by the elastic member 75, the magnetic disk 1 is axially displaced while the magnetic disk 1 and the spindle hub 23 are kept coaxial. When the screw 4 is further tightened, the bottom surface of the magnetic disk 1 comes into contact with the ring-shaped shim 85 of the aligning member 65, and finally is sandwiched between the flange portion 23c and the clamp 3 so as to be integrally rotatably fixed to the spindle hub 23. To be done.

According to the magnetic disk drive of the eighth embodiment,
By using the aligning member 65, the magnetic disk 1 and the spindle hub 23 can be processed by a normal clamping operation without making the working tolerance of the magnetic disk 1 and the gap for easily inserting the magnetic disk 1 strict. Disk 1
Can be mounted and fixed coaxially on the spindle hub 22. As a result, the pre-servo write disk can be easily mounted on the mass-produced magnetic disk device without misalignment, so that it is possible to provide the magnetic disk device capable of rotating the magnetic disk without rotational synchronization shake. Especially Example 8
Since the magnetic disk device of (1) is assembled by directly inserting the aligning member on which the magnetic disk 1 is placed into the disk insertion cylindrical portion of the spindle hub, it is suitable for a magnetic disk device of a type in which a plurality of magnetic disks are stacked and mounted. is there.

<< Ninth Embodiment >> FIG. 14 shows a ninth embodiment of the present invention.
4 is a cross-sectional view showing a state in which the magnetic disk 1 is fixed to the spindle hub 23 by the clamp 3 in the magnetic disk device of FIG. The structure for clamping the magnetic disk to the spindle motor in the magnetic disk device of the ninth embodiment is the same as that of the eighth embodiment.
1 and the configuration of the spindle hub and the aligning member is different. Therefore, the portions corresponding to those in the eighth embodiment are designated by the same reference numerals and the duplicate description will be omitted. 14
As shown in FIG. 13, a characteristic part of the magnetic disk device of the ninth embodiment is that the ring-shaped shim 85 of the aligning member 65 of the eighth embodiment shown in FIG. 13 is formed integrally with the spindle hub 24. . That is, a recess 24f is provided between the disk insertion cylindrical portion 24a of the spindle hub 24 and the flange portion 24c for fitting and fixing the aligning member 66 formed of an elastic material. On the outer peripheral side of the aligning member 66, there is an inclined surface 66a facing the chamfered portion 1b of the central hole 1a of the magnetic disk 1.

Also in the case of the magnetic disk device of the ninth embodiment,
By assembling in the same manner as in the eighth embodiment described with reference to FIG. 13, the central axis 24d of the spindle hub 24 and the central axis 1c of the magnetic disk 1 can be aligned and fixed rotatably. When applied to a magnetic disk device of a type in which a plurality of magnetic disks are stacked and mounted, the magnetic disk device of Example 9 is used for the lowermost magnetic disk, and for magnetic disks stacked above it. The thing of Example 8 may be used.

[0090]

As described in detail in the above embodiments, in the magnetic disk device of the present invention, the structure of the sloped surface formed at the inner peripheral end of the center hole of the magnetic disk and the disk insertion cylindrical portion of the spindle hub is described. By using the axial pressing force applied at the time of clamping by using, the magnetic disk is moved in the horizontal direction and the centering member is provided to correct the misalignment. According to the present invention, by using the aligning member, the magnetic disk can be spindle-mounted by only performing the clamping work without making the working tolerances of the magnetic disk and the spindle hub and the gap for inserting the magnetic disk particularly strict. It can be mounted and fixed coaxially on the hub.

As a result, the pre-servo write disk can be easily mounted on a mass-produced magnetic disk device without misalignment. Therefore, it is possible to provide a magnetic disk device capable of rotating the magnetic disk without rotation-synchronous shake. And
Since the magnetic disk can be rotated without the rotation synchronous shake, it is possible to provide a magnetic disk device capable of realizing data recording / reproduction with a high track pitch.

[Brief description of drawings]

FIG. 1 is a sectional view of essential parts showing a spindle motor and a clamp structure in a magnetic disk device according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of essential parts showing a state before fixing the magnetic disk to the spindle hub by the clamp in the magnetic disk device according to the first embodiment of the present invention.

3A is a cross-sectional view of a main part showing a state in which a magnetic disk is being fixed to a spindle hub by a clamp in a magnetic disk device according to a first embodiment of the present invention. FIG. 3B is an adjustment in the state of FIG. Enlarged sectional view showing the force applied to the core member

FIG. 4 is a cross-sectional view of essential parts showing a state in which a magnetic disk is fixed to a spindle hub by a clamp in the magnetic disk device according to the first embodiment of the present invention.

FIG. 5 is a cross-sectional view of essential parts showing a state in which a magnetic disk is fixed to a spindle hub by a clamp in a magnetic disk device according to a second embodiment of the present invention.

FIG. 6 is a sectional view of essential parts showing a state in which a magnetic disk is fixed to a spindle hub by a clamp in a magnetic disk device according to a third embodiment of the present invention.

FIG. 7 is a cross-sectional view of essential parts showing a state in which a magnetic disk is fixed to a spindle hub by a clamp in a magnetic disk device according to a fourth embodiment of the present invention.

FIG. 8 is a cross-sectional view of essential parts showing a state in which a magnetic disk is fixed to a spindle hub by a clamp in a magnetic disk device according to a fifth embodiment of the present invention.

FIG. 9 is a cross-sectional view of essential parts showing a state where a magnetic disk is fixed to a spindle hub by a clamp in a magnetic disk device according to a sixth embodiment of the present invention.

FIG. 10 is a cross-sectional view of essential parts showing a state before fixing a magnetic disk to a spindle hub by a clamp in a magnetic disk device according to a seventh embodiment of the present invention.

11A is a cross-sectional view of a main part showing a state in which a magnetic disk is being fixed to a spindle hub by a clamp in a magnetic disk device according to a seventh embodiment of the present invention. FIG. 11B is a sectional view in the state of FIG. Enlarged sectional view showing the force applied to the core member

FIG. 12 is a cross-sectional view of essential parts showing a state where a magnetic disk is fixed to a spindle hub by a clamp in a magnetic disk device according to a seventh embodiment of the present invention.

FIG. 13 is a cross-sectional view of essential parts showing a state in which a magnetic disk is fixed to a spindle hub by a clamp in a magnetic disk device according to an eighth embodiment of the present invention.

FIG. 14 is a cross-sectional view of essential parts showing a state in which a magnetic disk is fixed to a spindle hub by a clamp in a magnetic disk device according to a ninth embodiment of the present invention.

FIG. 15: sin θ * co with the angle θ of the inclined surface as a parameter
Graph showing sθ

FIG. 16 is a perspective view showing the configuration of a conventional magnetic disk device.

FIG. 17 is a plan view showing a method of incorporating a magnetic disk into a conventional magnetic disk device, where (a) is a mounting state of the magnetic disk on the spindle hub of the STW, and (b) is a spindle hub of the magnetic disk device. The mounting states of the magnetic disks are shown respectively.

[Explanation of symbols]

1 magnetic disk 1a central hole 1b chamfered portion 1c central axis of magnetic disk 2, 21, 22, 23, 24 spindle hub 2a, 21a, 22a, 23a, 24a disk insertion cylindrical portion 2b guide portion 2c, 21c, 22c, 23c, 24c Flange 2d, 21d, 22d, 23d, 24d Spindle hub center axes 2e, 21e, 22e, 23e, 24e Screw holes 3, 31 Clamps 3a, 31a Clamp center holes 3c, 31c Pressing part 4 Screw 4a Screw head 5 Spindle motor 6, 61, 62, 63, 64, 65, 66 Aligning member 6a, 61a, 62a, 63a, 64a, 65a, 66
a 1st inclined surface 6b, 61b, 62b, 63b, 64b, 65b 2nd
Inclined surfaces 6c, 61c, 62c, 63c Disk pressing portions 7, 71, 72, 75 Elastic members 8, 85 Ring-shaped shim 9 Elastic body 10 Rotor 11 Magnet 12 Yoke 13 Stator 14 Iron core 15 Coil 16 Motor bearing 16a Inner ring 16b Outer ring 17 motor shaft 22f inclined surface 24f concave portion 31d centering ring 63d curved surface 75a inner peripheral side surface

Claims (20)

[Claims] 1. A disk-inserting cylindrical portion of a magnetic disk for recording / reproducing information having a chamfered portion in the central hole, the cylindrical portion having a slanted guide portion for inserting into the central hole, and a flange on which the magnetic disk is to be mounted. A spindle hub having a portion, a first inclined surface facing the chamfered portion of the center hole of the magnetic disk, and a second inclined surface facing the inclined surface of the guide portion of the spindle hub, the magnetic disk Aligning member that is fitted and placed in the center hole of the clamp, a clamp that integrally fixes the magnetic disk and the aligning member to the spindle hub, and means that presses the clamp to fasten the spindle hub. And a spindle motor that rotates the spindle hub. 2. The aligning member has one of a first inclined surface facing the chamfered portion of the center hole of the magnetic disk and a second inclined surface facing the guide portion of the spindle hub. The magnetic disk drive according to claim 1, further comprising an elastic body. 3. The magnetic disk device according to claim 1, wherein the aligning member is made of an elastic material. 4. The magnetic according to claim 1, wherein a concave portion is provided on an outer peripheral side of an inclined surface facing the chamfered portion of the center hole of the magnetic disk of the aligning member. Disk device. 5. The magnetic disk drive according to claim 1, wherein the clamp has an inclined surface that acts as the centering member. 6. The chamfered portion of the magnetic disk and the first inclined surface of the aligning member contact each other when the clamp is axially pressed to apply an axial pressing force to the aligning member. Further, the guide portion of the spindle hub and the second inclined surface of the aligning member are configured to come into contact with each other, and the mutual force generated by the surface contact causes the aligning member to move toward the spindle hub. 6. The magnetic disk drive according to claim 1, wherein the magnetic disk is positionally corrected in the surface direction so that the central axis of the magnetic disk coincides with the central axis of the spindle hub. 7. The circumferential average value of the axial gap between the disk pressing portion provided on the aligning member and the surface of the magnetic disk before the axial pressing force is applied to the aligning member,
7. The magnetic disk drive according to claim 1, wherein a relative axial movement amount of the aligning member with respect to the magnetic disk by applying an axial pressing force, that is, an axial compression amount of the elastic member is larger than the axial movement amount. . 8. An axial pressing force is applied to the aligning member to mount the magnetic disk coaxially with respect to a central axis of the spindle hub, and then the disk pressing portion moves the magnetic disk to the spindle hub. The magnetic disk device according to claim 1, wherein the magnetic disk device is rotatably fixed to the magnetic disk device. 9. The magnetic disk device according to claim 1, wherein the axial pressing force applied to the aligning member is a clamping force by the clamp. 10. The inclined surface of the guide portion provided on the disk insertion cylindrical portion of the spindle hub is a chamfered inclined surface or a curved surface. The magnetic disk device described. 11. An inclined surface of at least one of a first inclined surface provided on the aligning member and facing the chamfered portion of the magnetic disk and a second inclined surface facing the guide portion of the spindle hub is a curved surface. 11. The magnetic disk device according to claim 1, wherein the inclined surface is a curved surface in which both inclined surfaces are continuously connected. 12. A spindle hub having a magnetic disk for recording / reproducing information, which has a chamfered portion in the center hole, and a disk insertion cylindrical portion for inserting into the center hole, and a flange portion on which the magnetic disk is to be mounted. A first inclined surface facing the chamfered portion of the central hole of the magnetic disk, and an inclined surface provided in the vicinity of a circle where the cylindrical surface of the disk insertion cylindrical portion of the spindle hub and the surface of the flange portion intersect. An aligning member having a second inclined surface facing each other and fitted in a center hole of the magnetic disk and placed on the flange portion; the magnetic disk and the aligning member integrated with the spindle hub A magnetic disk device including: a clamp for mechanically fixing the clamp; a means for pressing the clamp to fasten the spindle hub; and a spindle motor for rotating the spindle hub. 13. An elastic member is attached to the first inclined surface facing the chamfered portion of the center hole of the magnetic disk of the aligning member, or the first inclined surface is formed of an elastic member. 13. The magnetic disk device according to claim 12, wherein: 14. The magnetic disk device according to claim 12, wherein an elastic body is attached to a surface of the aligning member facing the flange portion of the spindle hub. 15. When a pressing force is applied to the magnetic disk in the axial direction, the chamfered portion of the center hole of the magnetic disk and the first inclined surface of the aligning member contact each other, and further the disk of the spindle hub. The inclined surface provided in the intersecting region of the insertion cylindrical portion and the flange portion and the second inclined surface of the aligning member are configured to come into contact with each other. 13. A member for correcting the position of the spindle hub in a direction within the surface of the magnetic disk, and aligning the central axis of the spindle hub with the central axis of the magnetic disk.
15. The magnetic disk device according to any one of 14. 16. A spindle hub having a disk insertion cylindrical portion for inserting into a central hole of an information recording / reproducing magnetic disk having a chamfered portion in the central hole, and a flange portion on which the magnetic disk is to be mounted, Elastic members are provided on the first inclined surface facing the chamfered portion of the center hole of the magnetic disk and on the inner peripheral portion facing the outer peripheral side surface of the disk insertion cylindrical portion of the spindle hub. A centering member having a peripheral diameter less than or equal to the outer peripheral diameter of the disk insertion cylindrical portion of the spindle hub, a clamp for integrally fixing the magnetic disk and the centering member to the spindle hub, and pressing the clamp. A magnetic disk device comprising means for fastening to the spindle hub, and a spindle motor for rotating the spindle hub. 17. An elastic member is provided on the first inclined surface of the aligning member facing the chamfered portion of the magnetic disk, or the first inclined surface is formed of an elastic member. The magnetic disk device according to claim 16. 18. The aligning member is disposed between the disc-inserting cylindrical portion of the spindle hub and the flange portion, and the aligning member is press-fitted or injection-molded into the disc-inserting cylindrical portion of the spindle hub, 18. The magnetic disk device according to claim 16, wherein the aligning member and the spindle hub are integrally provided. 19. A mutual reaction force generated by surface contact between the chamfered portion of the magnetic disk and the first inclined surface of the aligning member when an axial pressing force is applied to the magnetic disk,
And a mutual reaction force generated by elastic fitting between the outer peripheral side surface of the disk insertion cylindrical portion of the spindle hub and the elastic member provided on the inner peripheral portion of the centering member, whereby the centering member is moved with respect to the spindle hub. 19. The magnetic disk device according to claim 16, wherein position correction in a direction within the surface of the magnetic disk is performed so that the central axis of the magnetic disk coincides with the central axis of the spindle hub. 20. The pressing force applied in the axial direction to the magnetic disk is a clamping force.
20. The magnetic disk device according to any one of 19.