KR100896189B1 - Counterbalance, disk pack of hard disk drive with the counterbalance, and method of balancing a disk pack using the counterbalance - Google Patents

Abstract

The present invention relates to a spindle motor having a screw hole, a disk clamp having a screw hole mounted on an upper side of the spindle motor by a screw, and pressed by the disk clamp. Screws of the spindle motors aligned with respect to each other, the screws being coupled to the disk packs to obtain a rotational balance of the disk packs of the hard disk drive having at least one disk firmly coupled to the disk packs. Means for fitting into an open screw hole of a disc pack formed by a screw hole and a screw hole of the disc clamp; And a means for fixing the screw hole so as not to be detached from the screw hole, which is connected to the screw hole fitting means, and a disk pack of the hard disk drive having the counterweight. The present invention also provides a method for balancing a disc pack using the counterweight.

Description

Counterbalance, disk pack of hard disk drive with the counterbalance, and method of balancing a disk pack using the counterbalance}

1 is an exploded perspective view schematically showing a hard disk drive including a disk pack of the present invention.

FIG. 2 is a longitudinal cross-sectional view of the hard disk drive of FIG. 1.

3 is a perspective view of a disk pack according to a preferred embodiment of the present invention.

4 is an enlarged view of a portion of FIG. 2.

5A, 5B, and 5C are top, perspective, and side views of a counterweight in accordance with a first preferred embodiment of the present invention.

5D is a diagram illustrating the counterweight of FIG. 5C taken along the incision line 101.

6A, 6B, and 6C are top, side, and longitudinal cross-sectional views of a counterweight in accordance with a second preferred embodiment of the present invention.

7 is a diagram illustrating an apparatus for balancing a disk pack.

8 is a diagram illustrating another example of an apparatus for balancing a disk pack.

9A is a diagram illustrating in detail the program system of FIG. 8.

FIG. 9B is a view showing in detail the balancing operation for the screw holes shown in FIG. 9A.

10A is a view showing in detail the operation of selecting the counterweight for the screw hole shown in FIG. 9B.

FIG. 10B is a view showing in detail the operation of inserting the counterweight into the screw hole until the selected counterweight shown in FIG. 9B is inserted and fixed in the screw hole.

FIG. 11A is a view showing in detail the operation of selecting the counterweight for the screw hole shown in FIG. 9B.

FIG. 11B is a view showing in detail the operation of inserting the selected counterweight shown in FIG. 9B into the screw hole.

FIG. 12A shows the operation of inserting and fixing the selected counterweight shown in FIG. 11B into a screw hole. FIG.

FIG. 12B is a diagram further illustrating the program system of FIGS. 8 and 9A.

FIG. 13A is a view illustrating a process of inserting and fixing the counterweight shown in FIG. 11B in a screw hole.

FIG. 13B is a view illustrating a process of analyzing a disk pack for balancing the screw holes shown in FIG. 9.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hard disk drive, and more particularly to a balance weight for balancing a rotational balance of a disk pack, a disk pack of a hard disk drive provided with the balance weight, and the balance. A method of balancing disc packs using weights.

The hard disk drive includes a magnetic head associated with a rotating disk to record data on the disk or to reproduce data recorded on the disk. The disks included in the disk packs in the hard disk drive rotate at a high speed. The unbalance of the disk packs adversely affects the communication between the magnetic head and the rotating disk. Therefore, the disc pack must be balanced to minimize the discrepancy of rotation of the disc.

A typical prior art disc pack has a spindle motor, one or more discs, possibly one or more disc spacers, and a disc clamp. Bolts or screws couple the disk clamp to the spindle motor, which presses the disk and the disk spacer to the spindle motor. This forms a disk pack in which the disk clamp, disk spacer, and disk are firmly coupled to the spindle motor and rotate together.

The manufacture of disc packs involves the process of establishing a rotational balance. The rotation balancing process is a process of mechanically aligning the disc pack by attaching a counterweight. Balance tolerances for disk packs are measured by a balance measurement system and are typically managed to be within a tolerance of 35 mg-cm of angular momentum.

There are several ways to balance disk packs. Conventional balancing methods cause problems such as increased manufacturing costs or reduced reliability of manufactured hard disk drives.

The balancing method according to the first conventional example involves changing the outer circumferential portion in the form of a ring of the disk clamp. Cutting, drilling, or punching may be applied for this purpose.

The balancing method according to the second conventional example involves drilling one or more holes in a disk clamp or spindle motor hub. The spindle motor hub is the area of the spindle motor that includes a screw hole that is used to engage the disk clamp when manufacturing the disc pack. This method requires the formation of holes in the disc clamp or spindle motor hub, which can lead to contaminants such as machine tailing and machine oil. In addition, in the case of a disc pack having a specialized shape and a narrow tolerance range, the second example method has a problem of raising the cost of manufacturing a hard disk drive.

The balancing method according to the third conventional example involves injecting a selected amount of adhesive or heat seal plastic at a selected point near the disk clamp to balance the disk pack. Since the injection process such as adhesive releases contaminants, an additional cleaning process is required to restore the clean state when assembling the hard disk drive. The injected compound also requires special environmental conditions for proper curing. Therefore, there is a problem that causes an increase in the manufacturing cost, the production time is delayed until the curing process of the adhesive or the like is completed.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, a method for balancing a disk pack that does not cause specially processed disk clamps and contamination problems, a counterweight used for this, a disk pack provided with the counterweight, It is a technical object of the present invention to provide a method for balancing a disc pack using the counterweight.

In order to achieve the above technical problem, the present invention provides a spindle motor having a screw hole, a disk clamp having a screw hole mounted on an upper side of the spindle motor by a screw, and the disk. Coupled to the disk packs to establish a rotational balance of the disk packs of a hard disk drive having at least one disk pressurized by a clamp and firmly coupled to the spindle motor. Means for fitting into a screw hole of the spindle motor aligned with respect to the open screw hole of the disc pack formed by the screw hole of the disc clamp; And a means for fixing the screw hole so as not to be detached from the screw hole, which is connected to the screw hole fitting means, and a disk pack of the hard disk drive having the counterweight.

Preferably, the means for fitting into the screw hole may comprise a cylindrical shaft having a diameter insertable into the open screw hole of the disc pack.

Preferably, the means for securing the screw hole so as not to be released is compressed while passing through the screw hole of the disk clamp, but after passing therethrough is expanded to fix the counterweight at the disk clamp. It may have a compressible latch.

Preferably, the means for securing not to disengage from the screw hole is connected to the compression latch, the latch being inserted into the screw hole of the disk clamp when the compression latch is expanded through the screw hole of the disk clamp. It may further comprise a gap gap (latch gap zone).

Preferably, the means for securing not to disengage from the screw hole is connected to the latch gap region and located outside the screw hole of the disk clamp when the compression latch is expanded through the screw hole of the disk clamp. A counterweight head may be further provided.

Preferably, the compression latch may have a plurality of compressive fins projecting radially compressively.

Preferably, the counterweight can be formed of one material.

Preferably, the material may be plastic.

Preferably, the plastic may be nylon.

Preferably, the counterweight can be formed by cast.

The present invention also provides a spindle motor having a screw hole, a disk clamp having a screw hole mounted on an upper side of the spindle motor by a screw, and a spindle clamped by the disk clamp. A method of balancing a disk pack of a hard disk drive having at least one disk rigidly coupled to a motor, the method comprising: analyzing a balance of the disk pack; And a counterweight in the open screw holes of the disc pack formed by the screw holes of the spindle motor and the screw holes of the disc clamps aligned relative to each other when necessary to balance the disc pack. And inserting a pin to fix the disk pack so that the disk pack is not detached from the disk pack.

Preferably, the method of balancing the disk pack is one balance suitable for the balance adjustment operation from the set of counterweights comprising at least two counterweights each having a different total mass based on the balance analysis results of the disk packs. The method may further include selecting a weight.

Advantageously, said counterweight has a cylindrical shaft having a diameter insertable into an open screw hole of said disc pack, and said step of securing said counterweight to said disc pack comprises: said cylindrical shaft in an open screw hole of said disc pack. It may include the step of inserting.

Preferably, the counterweight has a compressible latch, and the step of securing the counterweight to the disc pack compresses the compression latch while passing through the screw hole of the disc clamp, after passing therethrough. May inflate to secure the counterweight so that it does not deviate from the disc clamp.

Advantageously, the method of balancing said disc pack comprises: identifying a failed balance adjustment of said disc pack having said balance added; Removing the disc clamp and all counterweights fixed to the disc pack from the disc pack to form an incomplete disc pack; And firmly coupling another disk clamp to the spindle motor of the incomplete disk pack to rebuild the disk pack.

Hereinafter, a counterweight according to a preferred embodiment of the present invention, a disc pack having the counterweight, and a method of balancing the disc pack using the counterweight will be described in detail with reference to the accompanying drawings.

The present invention includes at least one counterweight 100 to balance the disk pack 50 of the hard disk drive 10 shown in FIGS. The disk pack 50 has a spindle motor 80, a disk clamp 82, and at least one disk 12 pressurized by the disk clamp 82 and firmly coupled to the spindle motor 80. do. The disc pack 50 is aligned by at least two screw holes 85-A, 85-B (see FIG. 3). That is, as shown in FIG. 4, the screw holes 86a of the spindle motor 80 and the corresponding screw holes 86b of the disc clamp 82 are arranged in a straight line to connect the screws 95 (see FIG. 3) or A state in which the counterweight 100 can be fitted is a state in which the spindle motor 80 and the disc clamp 82 of the disc pack 50 are aligned. The disk pack 50 may further include a disk spacer 84.

1 is a schematic exploded perspective view of a hard disk drive having a balanced disk pack 50 employing a counterweight 100 according to a preferred embodiment. In addition, the hard disk drive 10 may include a hard disk drive base member 92, an embedded circuit 90 attached to a bottom surface of the base member 92, and a first disk 12 spaced by a disk spacer 84. ) And a voice coil actuator having a magnetic head, which is a medium for recording data on the second disk 14 and the disks 12 and 14 or reproducing the data recorded on the disks 12 and 14, 30 and a cover member 94.

2 is a cross-sectional view of the hard disk drive 10 showing the counterweight 100 inserted into one screw hole 85 -C. Insertion of the counterweight 100 forms a disc pack 50 that is at least partially balanced.

3 is a perspective view of the balanced disk pack 50 of FIGS. 1 and 2. Two counterweights 100 -A and 100 -B are inserted into two screw holes of the disc clamp 82. 3 also shows a disk clamp 82, a disk spacer 84, and a disk 12.

4 is an enlarged view of a portion of the cross-sectional view of FIG. 2. Counterweight 100 is engaged with the disk clamp 82 is shown to be fixed so as not to be separated. The counterweight 100 is fitted into the screw hole 85-C in which the screw hole 86a of the spindle motor 80 and the screw hole 86b of the disk clamp 82 are aligned.

The counterweight 100 of FIGS. 2 and 4 has a means for fitting into said screw hole and a means for engaging in at least one of a set of locking plates. The lock plate includes a disk clamp 82 and a spindle motor 80. In addition, the set of locking plates may include a disk spacer 84 fastened between the disk clamp 82 and the spindle motor 80.

The disk spacer 84 may or may not include a screw hole. In a hard disk drive having a plurality of disks, the disk pack 50 further includes one or more additional disk spacers 84 as shown in FIG. 2 to 4, a disk spacer 84 may also be provided in a hard disk drive having only one disk 12. As shown in FIG.

5A-6C illustrate various embodiments of counterweight 100.

5A to 5D are top, side, and side views of the counterweight 100 according to the first embodiment, and FIGS. 6A to 6C are top, side, and side views of the counterweight 100 according to the second embodiment. And a longitudinal sectional view. The counterweight 100 has a compressible latch 130. Preferably, the compression latch 130 is in the form of a ring having three compression pins (fin, 132, 134, 136) protruded in a compressible manner. FIG. 5D is a view illustrating the fins 132, 134, and 136 cut along the cut line 101 of FIG. 5C. Unlike the illustrated in FIG. 5D, the compression latch 130 may include two fins or four or more fins.

The counterweight 100 of the first and second embodiments has a cylindrical assembly 120 rigidly coupled to the latch assemblies 130, 132, 134, 136, 140 and the counterweight head 110. The cylindrical shaft 120 is centered on the first axis 122. The latch assemblies 130, 132, 134, 136, 140 are also centered around the first axis 122. The counterweight head 110 is firmly coupled to the latch gap zone 140.

The counterweight 100 of the first and second embodiments may be made of a material formed of the cylindrical shaft 120, the latch assemblies 130, 132, 134, 136, 140, and the counterweight head 110. Can be. The material may be essentially a castable material such as plastic. The plastic may preferably be one version of nylon. In a variant, the counterweight 100 may be formed of some other material.

In the present invention, since the balance of the disc pack 50 is adjusted by inserting the at least one counterweight 100 into the screw hole 85 -C of the disc pack 50, no contaminants are generated unlike the conventional case.

The counterweight head 110 of the counterweight 100 of the first and second embodiments has an inner surface 112, an outer surface 114, and side surfaces 116, 118. The counterweight 100 has a center of mass on the first axis 122 (see FIGS. 5A, 5C, 6A and 6B) when balancing the disc pack 50. The disc pack 50 may be balanced by fixing the counterweight 100 so that the cylindrical shaft 120 passes through the center of the screw hole 85 -C.

When inserting counterweight 100 into screw hole 85-C of disk pack 50, cylindrical shaft 120 is fitted into aligned screw hole 85-C (see FIG. 4). The compression latch 130 is compressed while passing through the screw hole 86b of the disk clamp 82, but is expanded after passing through the screw hole 86b to displace the counterweight 100 into the disc pack 50, More specifically, the disk clamp 82 is fixed so as not to be separated. As shown in FIG. 4, the diameter of the latch gap region 140 is slightly smaller than the inner diameter of the screw hole 85 -C, and the diameter of the expanded compression latch 130 is the diameter of the screw hole 85 -C. Larger than the inner diameter

The means for fitting the counterweight 100 into the at least one screw hole 85-C includes a cylindrical shaft 120, and secures the fitted counterweight 100 so as not to be released from the screw hole 85-C. Means for this include a compression latch 130, a latch gap region 140, and a counterweight head 110.

7 and 8 show two examples of supporting a method of balancing a disk pack according to the present invention.

The present invention includes a method for balancing a disk pack including selecting a counterweight suitable for a balance adjustment operation in the set of counterweights 470. The set of counterweights 470 is provided with at least two counterweights 480 and 482 each having a different total mass. According to the experiments by the inventors, counterweights 480 and 482 having a total mass of 24 mg and 54 mg, respectively, may be included in the set of counterweights 470.

7 shows a device for making an unbalanced disc pack 410 a balanced disc pack 420. The disk pack 410 includes a disk clamp 82 (see FIG. 1) and a spindle motor 80 (see FIG. 1) rigidly coupled to the disk clamp 82. The spindle motor 80 and the disc clamp 82 are aligned by at least two, preferably four screw holes 85 -A to 85 -D. That is, the screw holes of the spindle motor 80 and the corresponding screw holes of the disc clamp 82 are arranged in a straight line so that the screw 95 (see FIG. 3) or the counterweight 100 can be fitted. When the flow holes 85-A to 85-D are formed, the spindle motor 80 and the disk clamp 82 are aligned.

FIG. 8 shows an apparatus according to a preferred embodiment for making an unbalanced disc pack 410 a balanced disc pack 420 as in FIG. 7. The method of making the balanced disk pack 420 is implemented by the assembly workstation 400. The assembly workstation 400 is controlled by a computer executing a program system 530 configured including program steps residing in the memory 520.

The set of counterweight masses 450 includes at least two selectable total masses 460, 462. As shown in FIGS. 7 and 8, the total mass 460, 462 included in the set of counterweight masses 450 is the total mass of each counterweight 480, 482 included in the set of counterweights. Corresponds to.

Arrows 324 and 422 shown in FIGS. 7 and 8 preferably indicate means for inserting the selected counterweight 102 into the screw hole.

In the following, a method of balancing a disk pack will be described along the processing flow of the program system 530 shown in FIG. This simplifies the description but is not intended to limit the claims of the invention.

9A-13B show a method of balancing a disc pack using the counterweight of the present invention. Flow diagrams corresponding to the method of the present invention have arrows with reference numerals. These arrows represent the flow of control, sometimes the flow of data.

The computer 510 as used herein will include, but is not limited to, an instruction processor. The instruction processor includes at least one instruction processing element and at least one data processing element. Each data processing element is controlled by at least one of the instruction processing elements.

9A shows a program system 530 (see FIG. 8) for making a balanced disk pack 420 from an unbalanced disk pack 410 for each of the screw holes 85 -A through 85 -D. In operation 1002, the disk pack 410 is analyzed for balancing. In operation 1012, the screw holes are balanced.

9B shows the balancing operation for the screw holes in detail when the balancing operation is determined in the 1002 operation. In 1032 operation, counterweights for screw holes with a constant total mass are selected. In operation 1042, the counterweight is inserted into the screw hole until the selected counterweight is secured in the screw hole to form a disc pack that is at least partially balanced.

10A and 10B show an example of some possible implementations equivalent to the task of FIG. 9B. The execution example of FIGS. 10A and 10B is an execution example with a shared test.

FIG. 10A shows in detail one implementation equivalent to the 1032 task of FIG. 9B. The 1132 operation determines whether balancing is required for the screw holes. If yes (1134), the 1136 operation selects the counterweight for the screw hole with a constant total mass.

FIG. 10B shows in detail one implementation equivalent to task 1042 in FIG. 9B. The 1152 operation determines whether balancing is required for the screw holes. If yes (1154), in operation 1156, the selected counterweight is inserted into the screw hole until the selected counterweight is secured in the screw hole so that it does not deviate, thereby forming an at least partially balanced disc pack. .

FIG. 11A shows in detail the 1032 operation of FIG. 9B. In operation 1172, counterweights for screw holes are selected from the set of counterweights 470 and the set of counterweight masses 450 shown in FIGS. 7 and 8 to form counterweights with a constant total mass. That is, the total mass suitable for adjusting the balance of the disc pack 410 is selected from the two kinds of total masses 460 and 462 of the set of masses 450 of the counterweight mass, and the counterweight of the set of counterweights 470 is selected. A counterweight corresponding to the selected total mass is selected from 480 and 482.

The counterweight 102 selected in FIGS. 7 and 8 is one selected from the counterweights 480 and 482 belonging to the set of counterweights 470.

The arrows pointing to the counterweight selected in FIGS. 7 and 8 and the arrows pointing somewhere from the selected counterweight preferably mean an assembly feed mechanism for assembly.

FIG. 11B details the 1042 operation of FIG. 9B. In operation 1192, the selected counterweight 102 is inserted into the screw hole. In operation 1202, after the selected counterweight is inserted into the screw hole, the fitted counterweight is fixed so as not to be released from the screw hole.

12A shows details of operation 1202 of FIG. 11B. In operation 1212, the selected counterweight is inserted into the screw hole, and then the fitted counterweight is secured to the disc clamp so as not to be released from the screw hole.

FIG. 12B further prepares for disassembling the disc pack with counterweights so that at least the spindle motor and disc can be recycled in the event of a balancing failure in spite of the 1012 operation of balancing the disc pack (see FIG. 9A). The program system 530 (see FIG. 8) is shown in detail. This process is performed as follows. Task 1252 checks for disk pack rebalancing failures. In operation 1262, the disk clamp and all counterweights fixed to the disk clamp are removed from the disk pack to form an incomplete disk pack. Then, in operation 1272, another disk clamp is firmly coupled to the spindle motor of the incomplete disk pack and aligned by screw holes to rebuild the disk pack.

FIG. 13A shows in detail the balancing operation 120 operation for the screw holes of FIG. 11B. In operation 1302, the compression latch is compressed in the screw hole. In operation 1312, after the compression latch is compressed in the screw hole, the compression latch is expanded to fix the counterweight not to be released.

FIG. 13B shows a detailed operation 1002 of analyzing the disk pack of FIG. 9B. In operation 1352, the disk pack 410 used for the balance adjustment operation is analyzed using the disk pack balance adjustment mechanism 304 of FIG. Preferred disc pack balance mechanisms can be made by Hoffman.

Although the present invention has been described with reference to the embodiments shown in the drawings, this is merely exemplary, and it will be understood by those skilled in the art that various modifications and equivalent other embodiments are possible. Therefore, the true scope of protection of the present invention should be defined only by the appended claims.

According to the present invention, the disk clamp is not only subjected to special machining such as cutting and drilling, but also the disk pack can be balanced without injecting an adhesive or the like. Therefore, the generation of contaminants in the hard disk drive can be suppressed, the manufacturing cost of the hard disk drive can be reduced, and production delay can be suppressed.

Claims (25)

A spindle motor with a screw hole, a disk clamp with a screw hole mounted on an upper side of the spindle motor by a screw, and firmly coupled to the spindle motor by being pressed by the disk clamp. A counterweight coupled to the disk pack to obtain a rotational balance of a disk pack of a hard disk drive having at least one disk, wherein: The counterweight penetrates through the screw hole of the disk clamp and is inserted into the screw hole of the spindle motor aligned with respect to the disk clamp; A compressing latch connected to the cylindrical shaft and compressed while passing through the screw hole of the disc clamp, but expanding thereafter to secure the counterweight to the disc clamp so as not to be released from the disc clamp; A latch gap zone connected to the compression latch and inserted into the screw hole of the disk clamp when the compression latch is expanded through the screw hole of the disk clamp; And a counterweight head connected to the latch gap region and positioned outside the screw hole of the disk clamp when the compression latch is expanded through the screw hole of the disk clamp. delete delete delete delete According to claim 1, And the compression latch comprises a plurality of compressive fins projecting radially compressible. According to claim 1, Counterweight is characterized in that the counterweight is formed of one material. The method of claim 7, wherein Counterweight, characterized in that the material is plastic. The method of claim 8, Counterweight characterized in that the plastic is nylon (nylon). According to claim 1, The counterweight is a counterweight, characterized in that formed by casting (cast). A spindle motor with a screw hole, a disk clamp with a screw hole mounted on an upper side of the spindle motor by a screw, and firmly coupled to the spindle motor by being pressed by the disk clamp. In a disk pack of a hard disk drive having at least one disk, The disc pack further includes a counterweight coupled to the disc pack to establish a rotational balance of the disc pack, the counterweight passing through a screw hole of the disc clamp, aligned with the disc clamp. A cylindrical shaft inserted into the screw hole of the spindle motor; A compressing latch connected to the cylindrical shaft and compressed while passing through the screw hole of the disc clamp, but expanding thereafter to secure the counterweight to the disc clamp so as not to be released from the disc clamp; A latch gap zone connected to the compression latch and inserted into the screw hole of the disk clamp when the compression latch is expanded through the screw hole of the disk clamp; And a counterweight head connected to the latch gap region and positioned outside the screw hole of the disk clamp when the compression latch is expanded through the screw hole of the disk clamp. Disk pack. delete delete delete delete The method of claim 11, wherein And the compression latch comprises a plurality of compressive fins protruding in a radially compressible manner. The method of claim 11, wherein The counterweight is a disk pack of a hard disk drive, characterized in that formed of one material. The method of claim 17, The disk pack of the hard disk drive, characterized in that the material is plastic. The method of claim 18, The plastic pack is a disk pack of a hard disk drive, characterized in that the nylon (nylon). The method of claim 11, wherein The counterweight is a disk pack of the hard disk drive, characterized in that formed by casting (cast). A spindle motor with a screw hole, a disk clamp with a screw hole mounted on an upper side of the spindle motor by a screw, and firmly coupled to the spindle motor by being pressed by the disk clamp. 1. A method of balancing a disk pack of a hard disk drive having at least one disk, wherein: Analyzing the balance of the disk pack; Selecting one counterweight suitable for the balancing operation from the set of counterweights comprising at least two counterweights each having a different total mass based on the balance analysis results of the disc pack; And inserting the selected counterweight into the open screw hole of the disc pack formed by the screw holes of the spindle motor aligned with each other and the screw hole of the disc clamp so as not to be dislodged from the disc pack. And fixing the disk pack. delete The method of claim 21, The counterweight has a cylindrical shaft having a diameter insertable into an open screw hole of the disc pack, Securing the counterweight to the disc pack comprises inserting the cylindrical shaft into an open screw hole of the disc pack. The method of claim 21, The counterweight has a compressible latch, The fixing of the counterweight to the disc pack may include compressing the compression latch while passing through the screw hole of the disc clamp, and expanding after securing the counterweight to prevent the counterweight from being released from the disc clamp. How to balance the disk pack comprising a. The method of claim 21, Identifying a failure in balancing the disc pack having the balance added; Removing the disc clamp and all counterweights fixed to the disc pack from the disc pack to form an incomplete disc pack; And firmly coupling another disk clamp to the spindle motor of the incomplete disk pack to rebuild the disk pack.

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