JPH08263953A - Magnetic disk device and its assembly method - Google Patents

Abstract

PURPOSE: To write positioning information of good quality and to provide a smaller track pitch by suppressing vibration of a spindle and a base when a servo track is written. CONSTITUTION: A spindle assembly 30 is obtained by assembling rotor parts of a spindle motor, bearings and a fixing shaft, layering magnetic disks 3 via spacers on a hub and clamping them by a clamper. On the other hand, an actuator assembly 32 is obtained by assembling a fixing shaft, bearings, an arch, magnetic heads and actuator coils. The spindle assembly 3, the actuator assembly 32 and an actuator magnetic circuit 17 are fixed to a cover 2 by using screws 34, 35 and 36 respectively. Under this condition, the cover and the spindle and actuator assemblies are fixed to the base 41 of a servo track writing(STW) device 40. Since the rigidity of the base 41 of the STW device 40 is very high, vibration of the spindle and the base, etc., is suppressed in the case of STW, and a smaller track pitch can be provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of assembling a magnetic disk device used as an external storage device such as a computer, and more particularly to a configuration and a writing device for writing servo positioning information. Housings of this type of magnetic disk device are roughly classified into those having a split surface perpendicular to the surface of the magnetic disk and those having a base cover structure having a split surface horizontal to the magnetic disk surface. That is, the lower base and the upper cover constitute the housing of the magnetic disk device. 2. Description of the Related Art In recent years, with the thinning of magnetic disk devices, a base cover structure having excellent assemblability has been widely adopted. Further, as the track density of the magnetic disk has increased, the housing is required to have high rigidity, and therefore, the base is deepened to increase the bending rigidity.

[0002]

2. Description of the Related Art In a magnetic disk drive, servo track writing is performed to write positioning information on its own magnetic disk during the assembly process. FIG. 5 shows a conventional servo track writing method. In FIG. 5, 1 is the base,
3 is a magnetic disk, 4 is a hub, 5 is a spacer, 6 is a disk mounting reference flange portion of the hub, 7 is a clamper, 8 is a motor stator, 9 is a motor rotor magnet, 10 is a disk side bearing, 11 is a disk side fixed shaft, 12 is a magnetic head,
13 is an arm, 14 is a fixed shaft on the actuator side, 15 is a bearing on the actuator side, 16 is an actuator coil,
Reference numeral 17 is an actuator magnetic circuit. As shown,
In the case of a magnetic disk device having a base cover structure, most of the components of the magnetic disk device except a cover (not shown) and a printed wiring board (not shown) are assembled on the base 1 and then servo track writing is performed. A dedicated clock head 22 for reading and writing a reference clock is fixed to the stage 21 of the apparatus and is attached to one side of the magnetic disk (for example,
As shown in the drawing, the magnetic disk is loaded on the uppermost magnetic disk), and on the other hand, the movable portion of the actuator of the magnetic disk device is pushed by the actuator 23 different from its own actuator via the pin pick 24 to position and track each track. It is moved to perform servo track writing work. Of course, it is desirable to perform such a servo track writing operation with the cover attached, but in that case, holes for introducing the reference clock head 22 and the pin pick 24 are formed in the cover or the base. Since it is indispensable and workability is poor, in the case of a small-sized magnetic disk device, the cover is often removed as shown in the drawing.

It has also been attempted to mount a target (not shown) of a length measuring machine on the actuator of the magnetic disk device itself without using the pin pick 24 and perform positioning by the actuator itself. It is not used in recent small magnetic disk devices because of its large size and the fact that the movable part must be processed for mounting.

Some magnetic disk devices do not employ a self-servo information writing system for writing servo information by combining an actual magnetic disk laminated body and a magnetic head.
A method is used in which servo information is written in the state of a spindle assembly in which a magnetic disk is stacked on a spindle, using a head and a head actuator dedicated to writing servo tracks. However, in the embedded servo method, since servo information is written on all data surfaces,
When the deviation between the magnetic heads is large, the deviations occur in the radial direction and the circumferential direction of the magnetic disk, which deteriorates the performance of the magnetic disk device. Therefore, it is desirable to write the servo information while maintaining the combination of the spindle and the head actuator.

As a servo track writing method for a magnetic disk drive, Japanese Patent Laid-Open No. 5-36223 discloses a spindle motor for rotating a magnetic disk and a magnetic head for writing a servo track in the vicinity of the surface of the magnetic disk. , An actuator mechanism that moves the magnetic head to a desired track position, a position control circuit that drives the actuator mechanism, a servo pattern generation circuit that creates a servo pattern, a write amplifier that writes the servo pattern, and a write timing reference. A phase synchronization circuit for generating a clock signal, and the spindle motor further has a function of generating a synchronization signal for generating a reference clock signal of a write timing and inputting the synchronization signal to the phase synchronization circuit. A scheme is disclosed.

Further, in Japanese Patent Laid-Open No. 6-180953, a standard required for writing servo information in a servo information writing device for writing servo information in a sector servo system on a magnetic disk stacked in a magnetic disk device. A reference signal read / write head for reading / writing a signal from / to the magnetic disk, a plurality of servo information write heads inserted from the outside of the magnetic disk device so as to face the magnetic disk, and a plurality of servo information. A head positioning means for positioning the write head at a predetermined position on the magnetic disk; and a servo information transmission means capable of transmitting the servo information in parallel to the plurality of servo information write heads. A characteristic servo information writing device is disclosed.

[0007]

DISCLOSURE OF THE INVENTION In the present specification,
The "base" is defined as the side of the housing on which the stator part of the spindle motor and actuator is mounted. Also, in the case of an in-hub type and double-supported spindle, the stator side of the motor is not directly attached to the base or cover, so the side of the housing with the disk mounting flange of the spindle hub is the "base".
Is defined.

When performing servo track writing with the spindle portion and the actuator portion incorporated in the base, the magnetic disk must be rotated by the spindle motor of the magnetic disk device itself. In the case of the completed magnetic disk device, the vibration characteristic is not always the highest priority and the structure of the motor is not always determined, and the motor efficiency is often given priority in order to realize low power consumption.

Also, regarding the rigidity of the base, a sufficient rigidity is not always obtained due to the mutual relationship with the size. On the other hand, with the increase in track density, highly accurate positioning is required, but the accuracy at the time of writing servo information has a great influence on the positioning accuracy. In the case of spindle motors, 8-pole motors or 12-pole motors are often used, but in the case of recent high-speed rotation type spindles, when the number of poles increases, the precision of the control element is required to be high, and iron loss occurs. Because of the increased number, 8-pole motors are often used. In the case of an 8-pole motor, there are 6 slots, 9 slots, 12 slots, etc. In the 6-slot and 12-slot motors, the coils that are energized at the same time are distributed at equal angles with respect to the shaft, so the force is canceled and the vibration is small, but in the 9-slot motor, the force is unevenly distributed, so it is relatively Vibration increases. However, in the case of a small motor, the efficiency tends to decrease in 6 slots and 12 slots due to manufacturing problems. Moreover, the cost increases as the number of slots increases.

When performing servo track writing, the target magnetic disk device is fixed on the servo track writing device. However, since the fixing part and method are limited, the rigidity is greatly improved by fixing. Can't expect. In order to perform servo track writing by the motor of the magnetic disk device itself, a spindle motor connector or contact must be prepared for servo track writing.

Further, as described above, it is desirable to increase the height of the side wall in order to increase the rigidity of the base, but the assemblability deteriorates. In particular, when writing a servo track, it becomes difficult for the clock head to access the magnetic disk surface, as can be seen from FIG. In the case of the embedded servo, servo information is written on all data surfaces, so clock information must be written outside the writable range of the magnetic disk (actually, the stroke range between actuator stoppers). On the contrary, the radius of the clock information may limit the data writing area.

[0012]

According to a first aspect of the present invention, a magnetic disk, a means for rotating the magnetic disk, a magnetic head for reading and writing information, and a magnetic head for positioning the magnetic head to a track at an arbitrary position on the magnetic disk. Head actuator, and a housing that houses them,
The disk rotating means is composed of a rotor part and a stator part, the housing is composed of a base and a cover divided substantially parallel to the disk surface, and the stator part is attached to the base, or the disk is mounted on the base side. In a magnetic disk device in which a mounting reference surface side is located, and bearing portions of the disk rotating means and the head actuator are supported by both the base and the cover, the cover includes an assembly including the magnetic disk and a rotor portion, Provided is a method for assembling a magnetic disk device, wherein positioning information is written in a state where a head actuator is attached and a base is not attached, and then the base is attached.

In the second aspect, the writing of the positioning information is different from the disk rotating means of the magnetic disk device.
A method of assembling a magnetic disk device according to claim 1, wherein the magnetic disk is rotated by a rotating means provided by the positioning information writing device. According to a third aspect of the present invention, the rotor portion includes a rotor magnet of a spindle motor, and when writing the positioning information, the rotor magnet and a stator coil portion of the spindle motor on the side of the positioning information writing device are positioned to face each other and are not in contact with each other. The method of assembling the magnetic disk device according to claim 1, wherein the rotor unit on the magnetic disk device side is rotated by.

According to a fourth aspect of the present invention, the method of assembling the magnetic disk device according to the third aspect can be used to output reference clock information at the time of writing the positioning information, which is synchronized with the rotation of the spindle motor on the side of the positioning information writing device. A position writer having a possible encoder is provided. A fifth aspect provides a magnetic disk device assembled by the method according to any one of the first to third aspects.

[0015]

First, the spindle and the actuator are fixed to the cover. In this state, the positioning information is written by fixing the reverse end of the spindle actuator to a highly rigid servo track writing (STW) device. At this time, it is possible to rotate the spindle with a stator different from the stator used in the magnetic disk device by adopting a structure in which the rotor portion and the stator portion of the spindle motor can be easily separated. In this case, the STW-dedicated stator does not need to consider cost and efficiency.
It is possible to use a slot motor, and it is also possible to use a coreless motor or the like that is not a slot motor.

Further, the rotor magnet of the magnetic disk device may be used as a part of the magnet coupling instead of being used as the magnetic circuit of the motor, and a motor of very high precision and low vibration may be provided in the STW device.

[0017]

1 and 2 show a first embodiment of the present invention.
First, in FIG. 1, reference numeral 1 is a base, and 2 is a cover, which constitutes a housing of the magnetic disk device. The magnetic disk device shown in this embodiment uses a structure in which the base 1 side is deep and the cover 2 side is plate-shaped in order to increase the rigidity.

Reference numeral 3 is a magnetic disk, 4 is a hub, 5 is a spacer, 6 is a hub disk mounting reference flange portion, and 7 is a clamper, and a plurality of magnetic disks are laminated at predetermined intervals. Reference numeral 8 is a motor stator, 9 is a motor rotor magnet, 10 is a disk side bearing, and 11 is a disk side fixed shaft, which constitutes an outer ring rotating type spindle motor.

Reference numeral 12 is a magnetic head, 13 is an arm, 14 is a fixed shaft on the actuator side, and 15 is a bearing on the actuator side, which similarly constitutes an outer ring rotation type actuator. Each fixed shaft 11, 14 is a base 1 with a screw.
, And the opposite end surfaces of the fixed shafts 11 and 14 are also fixed to the cover 2 with screws. The magnetic circuit 17 of the actuator is also fixed to both the base 1 and the cover 2 by screws or adhesion. A stopper (not shown) that restricts the drive stroke of the actuator is directly attached to the base 1 or is formed by processing the base 1, and a part of the actuator movable portion abuts on this portion. It

The procedure for assembling the magnetic disk drive of this embodiment will be described below with reference to FIG. First, the rotor portion (that is, the hub 4 and the motor rotor magnet 9) of the spindle motor, the bearing 10 and the fixed shaft 11 are assembled, the magnetic disk 3 is stacked on the hub 4 via the spacer 5, and clamped by the clamper 7. In this way, the spindle assembly 30 is obtained. On the other hand, the fixed shaft 14, the bearing 15, the arm 13, the magnetic head 12 and the actuator coil 16 are assembled to obtain an actuator assembly 32.

The spindle assembly 30, the actuator assembly 32, and the actuator magnetic circuit 17 thus obtained are attached to the cover 2 with screws 34, 35,
Fix with 36 or the like. In this state, the cover spindle actuator assembly is fixed to the base 41 of the servo track writing (STW) device 40 as shown in FIG.

That is, the base 41 of the STW device 40 has a very high rigidity, and a rising portion 42 for supporting both ends of the cover 2 of the magnetic disk device, a portion 43 for retracting and positioning the spindle fixing shaft 11 and an actuator fixing. It has a portion 44 for retracting and positioning the shaft 14. Further, the STW device 40 uses the motor rotor magnet 9 of the magnetic disk device when mounting the assembly of the magnetic disk device.
STW stator coil 45 located inside the
It has a pin pick 46, an actuator 47 for driving the pin pick 45, and a reference clock head 48. Reference numerals 43a and 43b are drive units for retracting the fixed shaft.

In this embodiment, the STW stator coil 4
No. 5 is a 6-coil coreless motor, and the efficiency is slightly reduced, but there is no cogging and the torque generation is point-symmetrical, so the vibration is low. Of course, a slot motor may be used. The number of slots / coils does not necessarily have to match that of the motor stator 8 of the magnetic disk device.

On the lower surface of the lowermost magnetic disk, a dedicated head 48 for writing a reference clock is loaded from the STW device 40. Further, the magnetic head attached to the actuator 32 has a loading mechanism (not shown) attached to the STW device 40 so as to load the magnetic disk 3 on the STW device 40. As a result, in the pre-process of the servo track writing (STW) work,
It is possible to avoid damaging the magnetic head 12 and the magnetic disk 3.

The STW device 40 is also provided with a pin pick 46 for pushing and moving a part of the head carriage and an actuator 47 for driving the pin pick 46. Since the reference clock head 48 and the pin pick 46 described above can also be accessed from the lower side of the cover assembly, the mechanism is simple and the work of fixing the cover assembly to the STW device 40 is easy.

In this state, servo track writing (ST
W) Work is performed. The STW operation itself is performed in the same manner as the above-mentioned conventional device. Immediately after the STW work, the cover assembly is fixed to the base 1 on which the stator 8 (FIG. 1) of the spindle motor is already attached, and the printed wiring board (not shown) on which the electronic parts are mounted is assembled, and the assembly is performed. finish.

FIG. 3 shows a second embodiment of the present invention. In FIG. 3, 50 is an STW device, 51 is an STW device spindle, 52 is a bearing, 53 is an STW motor (rotor magnet), 54 is an STW motor (stator), 55 is a clock disk, and 56 is a clock head. . The difference from the first embodiment is that a motor for rotating the spindle of the magnetic disk device is provided on the STW device 50 side, and the spindle is rotated by the magnet coupling 60 using the rotor magnet 9 of the magnetic disk device. As shown in FIG. 4, the magnet coupling 60 uses a magnetic body having a groove corresponding to the number of poles of the rotor magnet 9 of the magnetic disk device, or a magnet. 4 shows this magnet coupling 60, 61 is a rotor yoke, 62
Is a coupling yoke, 63 is a groove, and 9 is a rotor magnet of the magnetic disk device.

When the magnetic coupling 60 is sufficiently strong, the coupling shift hardly changes during steady rotation, so the reference clock is the clock disk 55 mounted on the spindle 51 of the STW device 50 side.
Alternatively, an encoder (encoder) written on a drum (not shown) can be used. As a result, the reference clock head for writing on the magnetic disk 3 of the magnetic disk device can be omitted, and the data writing area can be expanded.
In FIG. 3, such a clock disk 55 is provided. The moment of inertia of the disk 55 is increased to stabilize the rotation as a flywheel.

As the power transmission, a non-contact magnetic coupling is desirable, but it is also possible to transmit the power by mechanical contact with a capstan or the like. In the first embodiment, in order to show the features of the present invention, an example of rotating the spindle of the magnetic disk device by the stators or motors on the STW devices 40 and 50 side is shown. It is also possible to rotate the to perform the servo track writing work.

[0030]

According to the present invention, since vibration of the spindle base during servo track writing (STW) can be suppressed, very high quality positioning information can be written, and a smaller track pitch can be realized. Further, when the clock information is not written to the data disk, the data area can be expanded, which leads to an increase in capacity. Further, since it is easy to mount the spindle and the actuator on the housing and the magnetic disk device at the time of STW, the workability is improved and the assembly cost can be reduced.

[Brief description of drawings]

FIG. 1 is a sectional view for explaining a first embodiment of a magnetic disk device of the present invention.

FIG. 2 is a sectional view showing a first embodiment of a servo positioning and assembling method for a magnetic disk device according to the present invention.

FIG. 3 is a sectional view showing a second embodiment of the present invention.

FIG. 4 is a diagram showing a magnet coupling used in a second embodiment of the present invention.

FIG. 5 is a sectional view for explaining a conventional method of assembling a magnetic disk device.

[Explanation of symbols]

 1 ... Base 2 ... Cover 3 ... Magnetic disk 4 ... Hub 5 ... Spacer 6 ... Disk mounting reference plane 7 ... Clamper 8 ... Motor stator 9 ... Motor rotor magnet 10 ... Bearing 11 ... Fixed shaft 12 ... Magnetic head 13 ... Arm 14 ... Fixed Shaft 15 ... Bearing 16 ... Actuator coil 17 ... Actuator magnetic circuit 40, 50 ... Servo track writing device 48 ... Clock head 60 ... Magnet coupling

Claims (5)

[Claims] 1. A magnetic disk, means for rotating the magnetic disk, a magnetic head for reading and writing information, a head actuator for positioning the magnetic head to a track at an arbitrary position of the magnetic disk, and a housing for them. A housing, the disk rotating means comprises a rotor part and a stator part, the housing comprises a base and a cover divided substantially parallel to the disk surface, and the stator part is attached to the base or the base. In the magnetic disk device in which the mounting reference surface side of the disk is located on the side, and the bearing portions of the disk rotating means and the head actuator are both supported by both the base and the cover, And the head actuator, and attach the base. A method of assembling a magnetic disk device, wherein positioning information is written in a state where the base is not attached, and then the base is attached. 2. The magnetic disk device according to claim 1, wherein the positioning information is written by a rotating means provided by the positioning information writing device, which is different from the disk rotating means of the magnetic disk device. Assembly method. 3. The rotor portion includes a rotor magnet of a spindle motor, and when writing positioning information, the rotor magnet and a stator coil portion of the spindle motor on the side of the positioning information writing device are positioned to face each other and are not in contact with each other. 2. The method for assembling a magnetic disk device according to claim 1, wherein the rotor unit on the magnetic disk device side is rotated by. 4. An encoder capable of outputting reference clock information at the time of writing positioning information, which is synchronized with the rotation of a spindle motor on the side of the positioning information writing device, using the method for assembling a magnetic disk device according to claim 3. And a positioning writing device. 5. A magnetic disk device assembled by the method according to claim 1.