HK1163921B - Disk drive with balance plug having longitudinal retainers - Google Patents

Description

Disk drive with balanced plug having longitudinal retention

Technical Field

Background

A Hard Disk Drive (HDD) is generally used in an electronic device such as a computer to record or reproduce data to or from a recording medium, which may be a magnetic disk having one or more recording surfaces. The HDD further includes a magnetic head for reading data on the recording surface of the magnetic disk and writing data on one of the surfaces. An actuator is provided for moving the head over a desired position or track of the disk.

The HDD includes a pivot motor that rotates the magnetic disk during operation. When the disk drive is operated and the actuator moves the head over the disk, the head flies a predetermined height above the recording surface of the disk while the disk is rotating, and the head detects and/or modifies the recording surface of the disk to retrieve, record and/or reproduce data from and/or record and/or reproduce data onto the disk.

The head can be rotated by an actuator to a position such that the head is not over the disk or recording surface when the HDD is not operating, or when the disk is not rotating. In this non-operational configuration, the head "parks" out of the recording surface of the disk.

Drawings

The general structure that implements the various features of the present disclosure will now be described with reference to the accompanying drawings. The drawings and the associated descriptions are provided to illustrate embodiments of the disclosure and not to limit the scope of the disclosure. In the drawings, reference numerals are repeatedly used to indicate correspondence between the marker elements.

FIG. 1 illustrates a perspective view of a disk drive according to one embodiment;

FIG. 2 illustrates a top view of a disk drive according to one embodiment;

FIG. 3 illustrates a perspective view of a disk holder according to one embodiment;

FIG. 4 illustrates a top view of a disk holder according to one embodiment;

FIG. 5 illustrates a partial cross-sectional view of a disk stack according to one embodiment; and

fig. 6 illustrates one embodiment of a balanced plug.

Detailed Description

Referring now to FIG. 1, an exploded perspective view of a disk drive 10 is illustrated in accordance with embodiments described herein. The disk drive 10 includes a head disk assembly (HAD) and a Printed Circuit Board Assembly (PCBA). The head disk assembly includes a disk drive housing having disk drive housing components such as a disk drive base 12 and a cover 14. A single disk or additional disks may be included in the disk drive.

Disk 16 includes an Inner Diameter (ID)18 and an Outer Diameter (OD) 20. The disc 16 also includes a plurality of tracks on its recording surface or face for storing data. The disk 16 may be a magnetic recording type storage device, however, other arrangements (e.g., optical recording) may be utilized. The head disk assembly also includes a pivot motor 22 for rotating the disk 16 about a disk axis 24. The head disk assembly also includes a head stack assembly 26 rotatably attached to the disk drive base 12 in operable communication with the disks 16. The head stack assembly 26 includes an actuator 28.

The actuator 28 includes an actuator body and at least one actuator arm 32 extending from the actuator body. Some embodiments include a plurality of arms 32. A suspension assembly 34 is attached at a distal end to the actuator arm 32. The suspension assemblies 34 each support a magnetic head 36. Suspension assembly 34 and head 36 are referred to as a head gimbal assembly. The number of actuator arms and suspension assemblies may vary depending on the number of disks and disk surfaces utilized.

The head 36 can include a transducer for writing and reading data. The transducer can include a writer and a read element. In magnetic recording applications, the writer of the transducer may be of longitudinal or perpendicular design, and the read element of the transducer may be inductive or magneto-resistive.

In optical and magneto-optical recording applications, the head may further include an objective lens and an active or passive mechanism for controlling separation of the objective lens from the disk surface of the disk 16. The disk 16 includes opposing disk surfaces. In magnetic recording applications, the disk surface typically includes one or more magnetic layers. Data may be recorded along a data ring area on either a single or both disk surfaces.

The head stack assembly 26 may be pivoted such that each head 36 is disposed adjacent a respective annular region of data from adjacent the outer diameter 20 of the disk 16 to the inner diameter 18 of the disk 16. In FIG. 1, the actuator body includes a bore, and the actuator 28 further includes a pivot bearing bushing 38 engaged in the bore to facilitate rotation of the actuator body about a rotational axis 40 between the restricted positions.

The actuator 28 can further include a coil support member 42 extending from a side of the actuator body opposite the actuator arm 32. The coil support member 42 is configured to support a coil 44. The VCM magnet 46 may be supported by the disk drive base 12. Posts may be provided to position the VCM magnets 46 in a desired alignment with the disk drive base 12. A VCM top plate 48 may be attached to the underside of the lid 14. In some embodiments the coil 44 is positioned between the VCM magnet 46 and the VCM top plate 48 to form a voice coil motor for controllably rotating the actuator 28.

The head stack assembly 26 can also include a flex cable assembly 50 and a cable connector 52. A cable connector 52 can be attached to disk drive base 12 and arranged in electrical communication with the printed circuit board assembly. The flex cable assembly 50 provides current to the coil 44 and carries signals between the head 36 and the printed circuit board assembly.

With this configuration, current flowing through the coil 44 results in a torque being applied to the actuator 28. The actuator 28 includes an actuator longitudinal axis 64 that extends generally along the actuator arm 32. The change in direction of the current through the coil 44 causes a change in direction of the torque applied to the actuator 28, and thus the longitudinal axis 64 of the actuator arm 32 rotates about the rotational axis 40. It is contemplated that other magnets, VCM plates, coils, and magnet support configurations may be utilized, such as multiple coil arrangements, single or dual VCM plates, and vertical coil arrangements.

The disk drive 10 can also include a latch 54. The latch 54 can include a fixed portion 56 securely coupled to the disk drive base 12. The lock 54 also includes a locking portion engageable with the fixed portion 56 to limit rotational movement of the actuator 28. Although the latch 54 is illustrated as being located at a corner of the base, the latch 54 may be located at other portions of the disk drive and still perform its function.

When the actuator 28 is rotated to the parked position, as illustrated in FIG. 1, the actuator 28 can include a contact member 76, which can be located on the coil support member 42 or elsewhere, configured to engage a crash stop 80 to limit rotation of the actuator 28 away from the disk 16. The hard stop 80 can be an integral part of the base 12, or the hard stop 80 can be connected to the base 12 via the fixation element 72. Fig. 1 illustrates the engagement shaft 66 of the contact member 76 and the hard stop 80 in line with the fixed element 72, although other configurations are also permissible. The hard stops 80 can also be provided to limit the movement of the actuator 28 toward the ID18 of the disk 16.

Data is recorded onto the surface of a disk in a pattern of concentric rings called data tracks. The disk surface is rotated at high speed by a motor hub assembly. The data tracks are recorded onto the disk surface by a head 36 which typically resides at the end of the actuator arm 32. Those skilled in the art will appreciate that what is described for one head disk assembly applies to multiple head disk assemblies.

The dynamic performance of HDDs is a major physical factor in achieving higher data capacity and faster manipulation of data. The number of data tracks recorded on the disk surface depends in part on how well the head 36 and the desired data tracks can be positioned relative to each other and follow each other in a stable and controlled manner. There are a number of factors that affect the ability of the HDD to perform the function of positioning the head 36 and following the data tracks with the head 36. Overall, these factors can be divided into two categories: factors that affect the motion of the magnetic head 36; and factors that affect the motion of the data track. The undesired movement is caused by undesired vibrations and undesired tolerances of the components.

During the development of HDDs, the magnetic disk 16 and the magnetic head 36 have undergone size reduction. Much of the improvement and reduction is due to consumer demand and demand for more compact and portable hard disk drives 10. For example, original hard disk drives had disk diameters many times larger than those being developed and envisioned.

Smaller drives typically have small parts with relatively very small tolerances. For example, the disk drive head 36 is designed to be positioned very close to the disk surface. Due to tight tolerances, the vibrational action of the actuator arm 32 relative to the disk 16 can negatively impact the performance of the HDD. For example, vibration of the actuator 28 can cause the spacing between the head element and the media to vary. In addition, irregular movement of the magnetic disk 16, or vibration caused by unbalanced rotation can cause variation in the spacing between the magnetic head element and the magnetic disk 16 or medium.

In addition, as the Track Per Inch (TPI) of the disk drive increases, so does the sensitivity to small vibrations. Small vibrations can cause significant off-track and degraded performance. For example, in many cases, variations in spacing between the head element and the media can increase the off-track complexity, and increasing the TPI increases the complexity and may cause data errors. These data errors can include hard errors during writing and soft errors during reading. In addition, vibration-induced errors become more pronounced as the actual offset distance and overall component size are reduced.

Each disk 16 is mounted on a rotatable hub 98 connected to pivot motor 22 and is secured to the rotatable hub by a disk clamp 100, as illustrated in FIG. 2. Some disk drives 10 include multiple disks 16 to provide additional disk surfaces for storing larger amounts of data. The resulting combination is referred to herein as a motor/disc assembly or disc pack 102.

A plurality of data storage disks 16 may be mounted in a vertical, generally equally spaced relationship on rotatable hub 98. One or more bearings 104 are disposed between a motor or pivot shaft 106 and the rotatable hub 98, which is disposed about the pivot shaft 106 and is rotatable relative to the pivot shaft 106. The hub 98 is rotated at a desired speed about the stationary shaft 106 using electromagnetic forces. Rotational movement of hub 98 is transferred to each disk 16 of disk pack 102, causing disk 16 to rotate with hub 98 about axis 106.

The disks rotate at high speeds about the shaft 106, and consumer demand for faster data acquisition can result in increased rotational speeds of the hub 98 and disks 16 to reduce the time to access data. Even a slight imbalance in the rotating motor/disc assembly 102 can produce significant forces that can adversely affect the ability to precisely position the heads 36 relative to the desired tracks of the corresponding discs 16 when reading from or writing to the discs 16. Excessive imbalance can degrade disk drive performance not only in terms of read/write errors, but also in terms of seek time. Excessive imbalance may lead to undesirable acoustic characteristics and may even lead to damage or excessive wear of individual disk drive components.

The inner diameter 18 of each disk 16 is slightly larger than the diameter of the outer edge of the pivot motor hub or rotatable hub 98 to allow the disk 16 to slide about the pivot motor hub 98 during installation. During assembly, the disk 16 may be positioned in a non-precise concentric manner about the pivot motor hub 98. Indeed, in some instances, the disk 16 may be intentionally offset from the pivot motor hub 98. This non-precise concentric relationship between the disks 16 and the motor hub 98 causes the disk pack 102 to become unbalanced. This imbalance can manifest in at least two ways.

First, the rotating mass of each disk 16 causes the centrifugal force to extend radially from the direction of the axis of rotation 24 in a plane orthogonal to the axis of rotation 24. This can be referred to as a single plane or "static" imbalance. Second, the same centrifugal force also causes a moment about the axis, extending from the axis of rotation 24, each plane being orthogonal to the axis of rotation 24 as a result of the coupling of the two different planes of imbalance. This may be referred to as biplane, biplane or "dynamic" imbalance.

The balancing of disk pack 102 is preferably performed, for example, by the manufacturer or during the assembly process, prior to shipping drive 10 to the customer. Single plane balancing of disk pack 102 can include attaching one or more weights to one side of disk pack 102. Not all imbalances can be mitigated to a desired degree by balancing within a single plane. In an attempt to ameliorate the potential deficiencies of single plane balancing, dual plane balancing of disk pack 102 can be achieved by attaching one or more counterweights along shaft 24 at two different heights corresponding to the vertically spaced reference planes.

Balancing of disk pack 102 can be achieved by attaching one or more weights to a central portion of disk pack 102. For example, as illustrated in fig. 2, disk pack 102 can have a portion that holds or is attached with one or more weights. FIG. 2 illustrates disk pack 102 having rotatable hub 98, rotatable hub 98 including a disk clamp 100 having a plurality of disk clamp apertures 110 positioned about a circumference of a central portion of disk pack 102.

As illustrated in fig. 2, the disk clamp apertures 110 can be substantially equidistant from the rotational axis 24 or equally spaced about the rotational axis 24. For example, the plurality of disk clamp apertures 110 can be positioned about the rotational axis 24 on a common reference circle having a center coincident with the rotational axis 24. The plurality of disk clamp apertures 110 can also include apertures positioned at different radial distances from the rotational axis 24 than the other plurality of disk clamp apertures.

In one embodiment, disk clamp 100 includes 8 disk clamp openings 110 positioned about rotational axis 24. The disk clamp 100 can include from about 4 disk clamp openings 110 to about 8 disk clamp openings 110. In one embodiment, the disk clamp 100 can include less than 4 disk clamp apertures 110, and in some embodiments, the disk clamp 100 can include more than 8 disk clamp apertures 110.

The disk clamp apertures 110 can be designed to be approximately the same size, and in some embodiments, the disk clamp apertures 110 can be designed to have apertures of different sizes. The different sized apertures can be positioned at different radial distances from the different sized apertures, or the different sized apertures can be positioned at equal radial distances from the axis of rotation to the different sized apertures.

When balancing disk pack 102, one or more weights can be disposed in one or more of disk clamp apertures 110 to stabilize disk pack 102 during operation. One or more counterweights can be used to offset the imbalance created during operation of the disk drive 10. For example, if an imbalance is created by rotational motion of disk pack 102 during operation of disk drive 10, one or more weights can be placed within disk clamp aperture 110 to offset the imbalance created by rotational motion of disk pack 102.

FIG. 3 illustrates a partially exploded view including a disk clamp 100 positionable on a disk pack 102 including one or more disks 16. As illustrated, the disk clamp 100 can include a plurality of disk clamp apertures 110 positioned about the rotational axis 24. As shown in fig. 3, the disk clamp apertures 110 can be positioned at substantially equal radial distances from the rotational axis 24 such that the disk clamp apertures 110 are positioned along a common reference circle having a center substantially coincident with the rotational axis 24.

Each disk clamp aperture 110 defines a disk clamp aperture axis 112 that extends generally through the respective disk clamp aperture 110. The disk clamp bore axis 112 of each respective disk clamp aperture 110 can be substantially parallel to the rotational axis 24. In some embodiments, one or more of the disk clamp bore axes 112 in the disk clamp apertures 110 can be positioned at an angle to the rotational axis 24. For example, in some embodiments, the disk clamp bore axis 112 can be positioned at an angle between about 20 ° and about 80 ° relative to the rotational axis 24, and in some embodiments, the disk clamp bore axis 112 can be positioned at an angle between about 30 ° and about 50 ° relative to the rotational axis 24.

In some embodiments, the disk clamp apertures 110 are symmetrically positioned about the rotational axis 24. In some embodiments, disk clamp 100 can include a disk clamp aperture 110 positioned asymmetrically about rotational axis 24. And in some embodiments, the disk clamp 100 can include some disk clamp apertures 110 positioned symmetrically about the axis of rotation 24 and other disk clamp apertures 110 positioned asymmetrically about the axis of rotation 24.

Fasteners 114 can be provided to secure disk clamp 100 to disk pack 102. As illustrated in fig. 3, the fastener 114 can be positioned in general alignment with the rotational axis 24. The fastener 114 is preferably threadedly received within the internal bore of the shaft 106.

FIG. 3 illustrates a balancing plug 120 that can be positioned in one or more disk clamp apertures 110 to balance disk pack 102. As illustrated, the balanced plug 120 is configured to be sized such that it can be received within the disk clamp aperture 110 and preferably through the disk clamp aperture 110. Although FIG. 3 shows only one balanced plug 120 received within disk clamp aperture 110, disk pack 102 can include a plurality of balanced plugs 120 received in at least one disk clamp aperture 110.

Fig. 4 illustrates a top view of a disk clamp 100 having a plurality of balanced plugs 120 residing within a plurality of disk clamp apertures 110. As exemplified by the embodiment shown in fig. 4, the disk clamp 100 can include a plurality of disk clamp apertures 110 positioned in a symmetrical manner about a central portion of the disk clamp 100. Although the disk clamp apertures 110 are positioned in a symmetrical manner, the positioning of the balanced plugs 120 within selected disk clamp apertures 110 need not be symmetrical.

FIG. 5 illustrates a partial cross-sectional view of a portion of disk pack 102, disk pack 102 including a rotatable motor hub 98 and a motor shaft or pivot 106 positioned about rotational axis 24. The disk pack 102 can include a plurality of disks 16 held in place by a disk clamp 100. Disk clamp 100 can include a plurality of disk clamp apertures 110 positioned around disk clamp 100 at a radial distance from rotational axis 24.

The motor hub recess 124 can extend from a top surface 126 of the motor hub 98. As illustrated, in one embodiment, the motor hub recess 124 extends into the motor hub 98 but does not extend to the bottom surface 128 of the motor hub 98. The motor hub 98 can include a plurality of motor hub recesses 124 positioned about the rotational axis.

In one embodiment, each of the plurality of motor hub recesses 124 is positioned about the rotational axis 24 at approximately the same radial distance as the other plurality of motor hub recesses 124. The motor hub recesses 124 can be symmetrically positioned about the rotational axis, and in some embodiments, the motor hub 98 can include motor hub recesses 124 that are asymmetrically positioned about the rotational axis 24. The motor hub recesses 124 can be positioned about the rotational axis 24 such that each motor hub recess 124 is aligned along a common reference circle that cuts a center that is substantially coincident with the rotational axis 24. In some embodiments, the motor hub recess 124 can extend into the motor hub 98 in a direction substantially parallel to the rotational axis 24.

As illustrated in fig. 5, disk clamp 100 is preferably rotatably positioned about rotational axis 24 such that at least one disk clamp aperture 110 is substantially aligned with at least one motor hub recess 124. In some embodiments, this orientation will allow the balanced plug 120 to be received through the disk clamp aperture 110 into at least a portion of the motor hub recess 124.

In one embodiment, at least one of the motor hub recess 124 and the disk clamp aperture 110 includes a cross-sectional dimension that is less than a cross-sectional dimension of the balance plug 120. For example, in one embodiment, the motor hub recess 124 can include a cross-sectional dimension that can be a diameter of the recess 124 that is smaller than a cross-sectional dimension that can be a diameter of the balance plug 120. In another example, in one embodiment, the disk clamp aperture 110 can include a cross-sectional dimension that can be a diameter of the aperture 110 that is less than a cross-sectional dimension that can be a diameter of the balance plug 120.

Thus, in some embodiments, the balancing plug 120 engages at least one of the disk clamp aperture 110 and the motor hub recess 124 when the balancing plug 120 is received into the disk clamp aperture 110, and in some embodiments into the motor hub recess 124. In some embodiments, at least a portion of the balancing plug 120 is plastically or elastically compressed or deformed when received into the disk clamp aperture 110, or when residing within the motor hub recess 124.

Fig. 6 illustrates one embodiment of a balanced plug 120 that can be used in conjunction with embodiments described in the present disclosure. The balance plug 120 preferably includes a cylindrical body 140 defining a top surface 142 and a bottom surface 144. The cylindrical body 140 also defines a cylindrical body shaft 146 that extends through a substantially central portion of the balance plug 120. The outer surface 148 extends around the circumference of the cylindrical body 140. At least one longitudinal retention member 150 also extends around the outer surface 148 of the cylindrical body 141, which extends in a direction between the top surface 142 and the bottom surface 144.

In one embodiment, at least one longitudinal retention member 150 extends in a direction along the outer surface 148 that is generally aligned with the body axis 146. In one embodiment, at least one longitudinal retention member 150 extends substantially parallel to body axis 146 along direction of outer surface 148. In some embodiments, the balance plug 120 can include a plurality of longitudinal retainers 150 extending around the outer surface 148 of the cylindrical body 140.

The longitudinal retainer 150 preferably extends in an outward direction from the outer surface 148 such that the longitudinal retainer 150 and the cylindrical body 140 have a cross-sectional dimension that is greater than the cross-sectional dimension of the cylindrical body 140 alone. For example, the longitudinal holder 150 can have a radial distance 152 extending from the body axis 146 of the longitudinal holder 150 to the outer surface that is greater than a radial distance 154 extending from the body axis 146 to the outer surface 148 of the cylindrical body 140.

In one embodiment, the balance plug 120 is received within the disk clamp opening 110 by deforming a portion of the balance plug 120. The balanced insertion of the plug 120 can be further aided by providing one or more chamfers 156 on the longitudinal retainer 150. For example, the longitudinal retainer 150 can include a chamfer 156 where the longitudinal retainer 150 meets at least one of the top surface 142 and the bottom surface of the cylindrical body 140. In one embodiment, as illustrated in FIG. 5, is received into a disk clamp opening 110. A portion of the disk clamp opening 110 is engageable with the chamfer 150. This configuration can limit movement of the balanced plug 120 within at least one of the disk clamp aperture 110 and the motor hub recess 124, and can further secure the balanced plug 120 from inadvertently moving out of its desired position or being positioned within the disk pack 102.

In some embodiments, disk pack 102 can have balanced plugs 120, all of which balanced plugs 120 have the same or substantially the same mass. In some embodiments, disk pack 102 can have balanced plugs 120 of different sizes and/or different masses. For example, in some embodiments, the balanced plugs 120 can be the same size and of different masses, which can be determined based on the desired effect that will be produced when inserted into the disk pack 102. As another example, the balanced plugs 120 can be of different sizes and of the same quality, which can be determined based on how the plugs 120 will affect the performance of the disk pack 102. In still other examples, the balanced plugs 120 can have different sizes and different masses.

In one embodiment, the disk drive 10 can include a pivot hub 98 having a top surface 126. The drive can further include a disk clamp 100 coupled to the pivot hub 98, and the disk clamp 100 can have a balanced plug or disk clamp aperture 110 positioned generally above the top surface 126 of the pivot hub 98 such that the plug aperture 110 defines an aperture axis 112 extending through the plug aperture 110 and the top surface 126. The disk drive 10 can further include a generally cylindrical balance plug 120. In one embodiment, the balanced plug 120 includes opposing ends 142, 144 and a generally cylindrical outer surface 148 defining a central axis 146 of the plug 120. The plug 120 can also have a protrusion 150 along the cylindrical outer surface 148 that extends between the opposing ends 142, 144 in a direction generally aligned with the central axis 146. The plug 120 is preferably sized and configured to be received through the plug aperture 110.

In one embodiment, the top surface further comprises at least one plug recess 124 configured to receive at least a portion of the balancing plug 120 when the balancing plug is received through the plug aperture 110. In some embodiments, the plug is sized such that an opposite end of the plug is positioned below a top surface of the disk clamp 100 when the plug is received through the plug aperture 110. In some embodiments, plug 120 is sized such that transition chamfer 156 engages the bottom of disk clamp 100 when plug 120 is positioned through plug opening 110. Some embodiments provide that the plug includes a transition chamfer 156 between at least one of the opposing ends and the protrusion.

In one embodiment of the balanced plug 120, the protrusion or longitudinal retainer 150 is substantially parallel to the main body or central axis 146. In one embodiment, the protrusion 150 includes a continuous portion extending between the opposing ends of the plug 120. In some embodiments, the protrusion 150 can be segmented or extend only partially between the opposing ends 142, 144 of the plug 120.

Some embodiments provide that the plug 120 is made of a single uniform material. In some embodiments, the single unified material is a polymer. In other embodiments, the plug 120 can be made of multiple materials. For example, in some embodiments plug 120 can have a metal forming plug body 140 and a molded polymer over the metal to form protrusion or longitudinal retainer 150. In some embodiments, the plug can be manufactured such that the material of the cylindrical body 140 and the material of the one or more protrusions 150 have different elastic moduli. In another example, the plug 120 can be made of two different polymers, and a polymer with a higher modulus of elasticity can form the cylindrical body 140, while a polymer with a lower modulus of elasticity can form the one or more protrusions 150. In yet another example, the plug 120 can form a lower modulus of elasticity polymer into the cylindrical body 140 and a higher modulus of elasticity polymer into the one or more protrusions 150.

Some embodiments provide that the balanced plug can include a generally cylindrical body defining a first end, a second end, a generally cylindrical outer surface, and a central axis of the plug. In some embodiments, the plug further comprises at least one protrusion extending along the cylindrical outer surface between the first and second ends in a direction generally aligned with the central axis of the plug.

Some embodiments provide a method of balancing a disk pack in a disk drive, the method comprising: a disk drive is provided having a pivot hub 98 having a top surface 126, and a disk clamp 100 is provided having a balanced plug aperture 110 positioned generally on the top surface 126 of the pivot hub 98 such that the plug aperture 110 defines an aperture axis 112 extending through the plug aperture 110 and a portion of the top surface 126. The method further includes providing a generally cylindrical balance plug 120 having opposite ends 142, 144 and a generally cylindrical outer surface 148 defining a central axis 146 of the plug 120, and pushing the plug through the plug aperture 110. The plug is held in some embodiments between the disk clamp 100 and the pivot boss 98 by a protrusion 150 along the cylindrical outer surface of the plug 120, and the protrusion preferably extends between the opposite ends in a direction generally aligned with the central axis.

The method can further provide that the top surface of the pivot hub includes a recess that receives a portion of the plug as the plug is pushed through the plug aperture. The method may further comprise pushing a plurality of balanced plugs across the disk clamp.

The description of the present invention is provided to enable any person skilled in the art to practice the various embodiments described herein. While the embodiments have been described in detail with reference to the various figures and disclosures, it is to be understood that these are for illustrative purposes only and are not to be construed as limiting the scope of the invention.

There may be many other ways of implementing the embodiments. The various functions and elements described herein may be divided differently than those shown without departing from the spirit and scope of the present disclosure. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments. Accordingly, many changes and modifications may be made to the embodiments by one having ordinary skill in the art without departing from the spirit and scope of the present disclosure.

Reference to a singular element is not intended to mean "one and only one" unless explicitly so stated, but rather "one or more. The terms "some" or "some" refer to one or more. Any headings and sub-headings are used for convenience, do not limit the disclosure, and are not referenced in connection with the interpretation of the description of the disclosure. All structural and functional equivalents to the elements of the various embodiments described in this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by this disclosure. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the above description.

Claims (26)

1. A disk drive, comprising:

a pivot hub having a top surface;

a disk clamp coupled to the pivot hub, the disk clamp having a balanced plug aperture positioned generally on a top surface of the pivot hub such that the plug aperture defines an aperture axis extending through the plug aperture and the top surface; and

a generally cylindrical balance plug having opposite ends and a generally cylindrical outer surface defining a central axis of the plug, the plug having a protrusion along the cylindrical outer surface extending between the opposite ends in a direction generally aligned with the central axis, the plug sized and configured to be received through the plug aperture.

2. The disk drive of claim 1, wherein the top surface further comprises at least one plug recess configured to receive at least a portion of the balanced plug when the balanced plug is received through the plug aperture.

3. The disk drive of claim 1 wherein the protrusion is substantially parallel to a central axis of the plug.

4. The disk drive of claim 1, wherein the plug is sized such that an opposite end of the plug is positioned below a top surface of the disk clamp when the plug is received through the plug aperture.

5. The disk drive of claim 1 wherein the plug includes a transition chamfer between at least one of the opposing ends and the protrusion.

6. The disk drive of claim 5, wherein the plug is sized such that the transition chamfer engages a bottom of the disk clamp when the plug is positioned through the plug aperture.

7. The disk drive of claim 1 wherein the protrusion comprises a continuous portion extending between opposite ends of the plug.

8. The disk drive of claim 1 wherein the plug comprises a uniform material.

9. The disk drive of claim 8 wherein the material comprises a polymer.

10. The disk drive of claim 1 wherein the plug comprises a plurality of materials.

11. The disk drive of claim 10 wherein the protrusion comprises a material having a different modulus of elasticity than other materials of the balanced plug.

12. The disk drive of claim 1 wherein the plug comprises a plurality of protrusions positioned about the cylindrical outer surface, each of the plurality of protrusions having a radial dimension from the central axis that is greater than a radial dimension of the plug's generally cylindrical surface.

13. The disk drive of claim 1 wherein the plug comprises 2 to 6 protrusions positioned around the outer cylindrical surface.

14. A balanced plug for a disk drive, the balanced plug comprising:

a generally cylindrical body defining a first end, a second end, a generally cylindrical outer surface, and a plug central axis; and

a protrusion extending along the outer cylindrical surface between the first and second ends in a direction generally aligned with the plug central axis.

15. The plug of claim 14, wherein the protrusion is substantially parallel to a central axis of the plug.

16. The plug of claim 14, wherein the plug includes a transition chamfer between the protrusion and at least one of the first and second ends.

17. The plug of claim 14, wherein the protrusion includes a continuous portion extending between the first end and the second end of the plug.

18. The plug of claim 14, wherein the plug comprises a uniform material.

19. The plug according to claim 18 wherein said unifying material comprises a polymer.

20. The plug of claim 14, wherein the plug comprises a plurality of protrusions positioned about the cylindrical outer surface, each of the plurality of protrusions having a radial dimension from the central axis that is greater than a radial dimension of the substantially cylindrical surface of the plug.

21. The plug of claim 14, wherein the plug comprises 2 to 6 protrusions positioned about the cylindrical outer surface.

22. The plug of claim 14, wherein the plug comprises a plurality of materials.

23. The plug of claim 22, wherein the protrusion comprises a material having a different modulus of elasticity than other materials of the balanced plug.

24. A method of balancing a disk pack in a disk drive, the method comprising:

providing a disk drive having a pivot hub with a top surface;

providing a disk clamp having a balanced plug aperture positioned generally on a top surface of the pivot hub such that the plug aperture defines a bore axis extending through the top surface and the plug aperture;

providing a generally cylindrical balance plug having opposite ends and a generally cylindrical outer surface defining a central axis of the plug;

pushing the plug through the plug opening; and

the balance plug is retained between the disk clamp and the pivot boss by a protrusion along a cylindrical outer surface of the plug that extends between the opposing ends in a direction generally aligned with the central axis.

25. The method of claim 24, wherein a top surface of the pivot hub includes a recess that receives a portion of the plug as the plug is pushed through the plug aperture.

26. The method of claim 24, further comprising pushing a plurality of balanced plugs across the disk clamp.