Disk drive with airflow channeling enclosure

A disk drive includes a disk drive base, a disk, and a head stack assembly rotatably coupled to the base adjacent the disk surface of the disk. The disk drive includes an airflow channeling enclosure. The enclosure includes an airflow inlet disposed downstream of the head stack assembly and configured to receive the disk rotation induced airflow therethrough. The enclosure further includes an airflow channel extending along the disk surface from the airflow inlet. The enclosure further includes an outer wall extending along the disk surface from the airflow inlet and defining the airflow channel radially interior to the outer wall. The enclosure further includes an airflow outlet disposed upstream of the head stack assembly extending from the outer wall and the channel opposite the airflow inlet for modifying the disk rotation induced airflow passing from the channel.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to disk drives, and in particular to a disk drive including an airflow channeling enclosure.

2. Description of the Prior Art

The typical hard disk drive includes a head disk assembly (HDA) and a printed circuit board assembly (PCBA) attached to a disk drive base of the HDA. The head disk assembly includes the disk drive base, a cover, at least one magnetic disk, a spindle motor for rotating the disk, and a head stack assembly (HSA) that includes a transducer head supported by a slider (collectively referred to as “head” or “slider”) for reading and writing data from and to the disk.

The spindle motor includes a spindle motor hub that is rotatably coupled to the disk drive base. The spindle motor hub has an outer hub flange that supports a lowermost one of the disks. Additional disks may be stacked and separated with annular disk spacers that are disposed about the spindle motor hub. The spindle motor typically includes a spindle motor base that is attached to the disk drive base. A shaft is coupled to the spindle motor base and the spindle motor hub surrounds the shaft. The spindle motor hub may be rotatably coupled to the shaft and therefore the spindle motor base typically via a pair of bearing sets. A stator is positioned about the shaft and is attached to the spindle motor base. A magnet element is attached to the hub flange. The stator includes windings that selectively conduct current to create a magnetic field that interacts with the various poles of the magnet element. Such interaction results in forces applied to the spindle motor hub that tend to rotate the spindle motor hub and the attached disks.

The printed circuit board assembly includes a servo control system in the form of a disk controller for generating servo control signals. The head stack assembly is controllably positioned in response to the generated servo control signals from the disk controller. In so doing, the attached sliders are moved relative to tracks disposed upon the disk.

The head stack assembly includes an actuator assembly including the sliders and a flex circuit cable assembly attached to the actuator assembly. A conventional “rotary” actuator assembly (also referred to as “rotary actuator” or simply “actuator”) typically comprises an actuator body, a pivot bearing cartridge, a coil portion that extends from one side of the actuator body to interact with one or more permanent magnets to form a voice coil motor, and one or more actuator arms which extend from an opposite side of the actuator body to a distal end of the actuator assembly. The actuator body includes a bore and the pivot bearing cartridge engaged within the bore for allowing the actuator body to rotate between limited positions. At least one head gimbal assembly (HGA) is distally attached to each of the actuator arms. Each head gimbal assembly biases a head towards the disk. In this regard, the actuator assembly is controllably rotated so as to move the heads relative to the disks for reading and writing operations with respect to the tracks contained on the disks.

A topic of concern is the desire to reduce the effects of airflow generated within the disk drive due to rotation of the disks. Of particular concern is the occurrence of turbulent airflow which may tend to excite a resonance response of the actuator assembly. This results in an increase in the percent off-track values of the associated head. Further, such disk rotation induced airflow may result in a force applied to the actuator assembly, i.e., windage. In addition, such disk rotation induced airflow may result in vibration of the disks or disk flutter.

Another topic of concern is contamination within the disk drive, and in particular, the rate and efficiency of filtering contamination. Various airflow circulation filtering systems have been utilized in the art with varying degrees of effectiveness. A typical arrangement is to provide a vertically disposed rectangular filter within a cavity of the disk drive.

Accordingly, there is a need in the art for an improved disk drive configuration for filtering and mitigation of disk rotation induced airflow in comparison to the prior art.

SUMMARY OF THE INVENTION

According to an aspect of the present invention, there is provided a disk drive. The disk drive includes a disk drive base, and a disk rotatably coupled to the disk drive base. The disk includes a disk surface and defines an axis of rotation. The disk drive further includes a head stack assembly rotatably coupled to the disk drive base adjacent the disk surface. The disk drive further includes an airflow channeling enclosure disposed adjacent to and spaced apart from the disk surface. The airflow channeling enclosure includes an airflow inlet disposed downstream of the head stack assembly with respect to disk rotation induced airflow and configured to receive the disk rotation induced airflow therethrough. The airflow channeling enclosure further includes an airflow channel extending along the disk surface from the airflow inlet. The airflow channeling enclosure further includes an outer wall extending along the disk surface from the airflow inlet and defining the airflow channel radially interior to the outer wall with respect to the disk. The airflow channeling enclosure further includes an airflow outlet disposed upstream of the head stack assembly extending from the outer wall and the airflow channel opposite the airflow inlet for modifying the disk rotation induced airflow passing from the airflow channel.

According to various embodiments, the airflow channeling enclosure may include a first plate disposed parallel to and along the disk surface. The first plate extends from the outer wall radially interior with respect to the disk and extends between the airflow inlet and the airflow outlet to further define the airflow channel. The airflow channeling enclosure may include a second plate disposed parallel to the first plate. The second plate extends from the outer wall radially interior with respect to the disk with the outer wall being between the first and second plates, and the second plate extends between the airflow inlet and the airflow outlet to further define the airflow channel. The first plate may be formed of a solid material, such as a plastic material.

In addition, the airflow channeling enclosure may include an outlet filter disposed across the airflow outlet. The airflow channeling enclosure may include an inner wall extending along the disk surface from the airflow inlet and defining the airflow channel radially exterior to the inner wall with respect to the disk. The inner wall may be formed of a filter material for modifying the disk rotation induced airflow exiting the channel through the inner wall. The airflow channeling enclosure may include an outlet filter disposed across the airflow outlet with the outlet filter being formed of a filter material having a porosity finer than a porosity of the filter material of the inner wall. The disk may include an outer edge, and the outer wall may extend adjacent the outer edge. The outer wall may be formed of a solid material. The airflow channeling enclosure may extend in an arc at least 180 degrees with respect to the axis of rotation of the disk.

According to another aspect of the present invention, there is provided a disk drive. The disk drive includes a disk drive base, and a disk rotatably coupled to the disk drive base. The disk includes a disk surface and defines an axis of rotation. The disk drive further includes a head stack assembly rotatably coupled to the disk drive base adjacent the disk surface. The disk drive further includes an airflow channeling enclosure disposed adjacent to and spaced apart from the disk surface. The airflow channeling enclosure includes an open airflow inlet configured to receive the disk rotation induced airflow therethrough. The airflow channeling enclosure further includes an airflow channel extending along the disk surface from the airflow inlet. The airflow channeling enclosure further includes an outer wall extending along the disk surface from the airflow inlet and defining the airflow channel radially interior to the outer wall with respect to the disk. The airflow channeling enclosure further includes an airflow outlet disposed upstream of the head stack assembly extending from the outer wall and the airflow channel opposite the airflow inlet for modifying the disk rotation induced airflow passing from the airflow channel.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the drawings wherein the showings are for purposes of illustrating preferred embodiments of the present invention only, and not for purposes of limiting the same,FIGS. 1-6illustrate a disk drive including airflow channeling enclosures in accordance with aspects of the present invention.

Referring now toFIG. 1there is depicted an exploded perspective view of a disk drive10constructed in accordance with an aspect of the present invention. In the embodiment shown, the disk drive10includes a head disk assembly (HDA)12and a printed circuit board assembly (PCBA)14. The head disk assembly12includes a housing which may include a disk drive base16and a cover18that collectively house magnetic disks20,22. Each magnetic disk20,22contains a plurality of tracks for storing data. The disks20,22may be two-sided, and thus for example, the magnetic disk20is shown having a track24on an upper disk surface28and a track26(shown in phantom) on a lower disk surface30. The disks20,22each include an inner edge32and an outer edge34.

The head disk assembly12further includes a spindle motor36for rotating the magnetic disks20,22about an axis of rotation38. The head disk assembly12further includes a head stack assembly40and a pivot bearing cartridge42. The head stack assembly40includes a rotary actuator44. The rotary actuator44includes an actuator body46that has a bore and the pivot bearing cartridge42is engaged within the bore for facilitating the rotary actuator44to rotate between limited positions. The rotary actuator44further includes a coil portion48that extends from one side of the actuator body46. The coil portion48includes a coil that is configured to interact with a pair of permanent magnets52to form a voice coil motor for pivoting the rotary actuator44about a pivot axis50.

A plurality of actuator arms, the lowermost one of which being denoted54, extends from an opposite side of the actuator body46. As the disks20,22may be two-sided, each of the actuator arms includes either one or two head gimbal assemblies associated with the adjacent sides of the disks20,22. Each head gimbal assembly includes an air bearing slider or slider (the lowermost one being denoted56). Each air bearing slider56is contemplated to include a transducer head for reading and writing data from and to the disks20,22.

The spindle motor36includes a spindle motor hub58that is rotatably attached to the disk drive base16. The spindle motor hub58has a hub body60and a hub flange62that extends from the hub body60. The hub flange62includes a supporting surface for supporting a lowermost one of the disks, namely disk22. The remaining disk20is stacked on disk22and separated with an annular disk spacer64that is disposed about the hub body60. A disk clamp66is attached about the spindle motor hub58and is utilized to apply a clamping force against the topmost disk20for securing all the disks20,22to the spindle motor hub58. The spindle motor36may further include a spindle motor base68that is mounted to the disk drive base16.

As will be discussed in further detail below, in the embodiment shown, the disk drive10includes airflow channeling enclosures70,72,74which are generally configured to modify and filter disk rotation induced airflow within the disk drive10. It is understood that such airflow diverter filter components70,72,74represent various aspects of the present invention and that the invention may be practiced with any one of such components70,72,74or in combination such as shown in this particular embodiment.

Referring now toFIG. 1there is depicted an exploded perspective view of the disk drive10. An enlarged perspective view of the assembled disk drive10is shown without the cover18inFIG. 2.FIG. 3depicted an enlarged plan view of selected components of the disk drive ofFIG. 2including the airflow channeling enclosure70, the disk20, and the head stack assembly40. An enlarged perspective view of the airflow channeling enclosure70is shown inFIG. 4, and an exploded perspective view of the airflow channeling enclosure70is shown inFIG. 5.

According to an aspect of the present invention, there is provided the disk drive10. The disk drive10includes the disk drive base16, and a disk, such as disk20, rotatably coupled to the disk drive base16. The disk20includes a disk surface, such as the upper disk surface28, and defines the axis of rotation38. The disk drive10further includes the head stack assembly40rotatably coupled to the disk drive base16adjacent the disk surface28. The disk drive10further includes an airflow channeling enclosure, such as the airflow channeling enclosure70, disposed adjacent to and spaced apart from the disk surface28. The airflow channeling enclosure70includes an airflow inlet76disposed downstream of the head stack assembly40with respect to disk rotation induced airflow and configured to receive the disk rotation induced airflow therethrough. The airflow channeling enclosure70further includes an airflow channel78extending along the disk surface28from the airflow inlet76. The airflow channeling enclosure70further includes an outer wall80extending along the disk surface28from the airflow inlet76and defining the airflow channel78radially interior to the outer wall80with respect to the disk20. The airflow channeling enclosure70further includes an airflow outlet82disposed upstream of the head stack assembly40extending from the outer wall80and the airflow channel78opposite the airflow inlet76for modifying the disk rotation induced airflow passing from the airflow channel78.

In further detail, in the views ofFIGS. 1-3, the disks20,22are configured to rotate in a counter-clockwise direction. As such, the airflow inlet76receives disk rotation induced airflow downstream of the head stack assembly40and channels it through the airflow channeling enclosure70in the airflow channel80.

It is contemplated that disk rotation induced airflow that may result in vibration of the disks20,22or disk flutter. As such, utilization of the airflow channeling enclosures70,72,74may generally reduce disk rotation induced airflow and therefore may mitigate disk flutter. This is especially the case with this particular aspect of the invention with the airflow inlet76being disposed downstream of the head stack assembly40and the airflow outlet82being disposed upstream of the head stack assembly40. In this regard, in this embodiment, the airflow channeling enclosure70provides coverage adjacent the disk20from downstream of the head stack assembly40to upstream of the head stack assembly40. Additionally, the airflow channeling enclosure70may extend in an arc at least 180 degrees with respect to the axis of rotation38of the disk20, such as it the case with the particular embodiment shown.

As used herein the terms upstream and downstream refer to regions bisected by a plane that includes the pivot axis50associated with the head stack assembly40and the axis of rotation38associated with the spindle motor36and the disks20,22. In the plan view ofFIG. 3, as the disks20,22are configured to rotate counter-clockwise, the region to the right of a line through the pivot axis50and the axis of rotation38would be considered to be downstream of the head stack assembly40, and the region to the left of such line would be considered to be upstream of the head stack assembly40.

In this embodiment, the airflow channeling enclosure70includes a first plate84disposed parallel to and along the disk surface28. The first plate84extends from the outer wall80radially interior with respect to the disk20and extends between the airflow inlet76and the airflow outlet82to further define the airflow channel78. In addition, the airflow channeling enclosure70may include a second plate86disposed parallel to the first plate84. The second plate86extends from the outer wall80radially interior with respect to the disk20with the outer wall80being between the first and second plates84,86. The second plate86extends between the airflow inlet76and the airflow outlet82to further define the airflow channel78.

It is contemplated that the first plate84, the second plate86and the outer wall80may be an integrally formed element or separately formed and later attached elements. The first plate84, the second plate86and the outer wall80may be formed of various materials which may be chosen from those which are well known in the art such as plastic. In the case where such elements are integrally formed, molded plastic may be used for example.

The outer wall80may be disposed a various radial locations with respect to the disk20. In this particular embodiment show, the outer wall80is uniformed radially spaced from the axis of rotation38and extends adjacent the outer edge34of the disk20.

In addition, the airflow channeling enclosure70may include an inner wall88extending along the disk surface28from the airflow inlet76to the airflow outlet82. The radial position of the inner wall88may be disposed at various radial positions and need not be required to be flush with the disk clamp66as shown. Moreover, the inner wall88need not be of a constant radial distance from the axis of rotation38as shown and may have a varying radial distance. The inner wall88further defines the airflow channel78radially exterior to the inner wall88with respect to the disk20. The inner wall88may be formed of a filter material for modifying the disk rotation induced airflow exiting the airflow channel78through the inner wall88. The inner wall88may be disposed at various radial locations with respect to the disk20. In this particular embodiment shown, the inner wall88is uniformed radially spaced from the axis of rotation38and extend adjacent the disk clamp66.

The airflow channeling enclosure70may include an outlet filter90disposed across the airflow outlet82. The outlet filter90may be formed of a filter material having a porosity finer than a porosity of the filter material of the inner wall88.

The airflow channeling enclosure70is configured such that disk rotation induced airflow generally enters the airflow channel80through the airflow inlet76and exits through the airflow outlet82and the inner wall88. It is contemplated that contaminants may tend to become “trapped” and collected by in the airflow channel78, in addition to a tendency of the outlet filter90and the inner wall88themselves to retain filtered contaminants. It is further contemplated that the airflow channeling enclosure70tends to slow the exiting disk rotation induced airflow, and therefore reduces the impact of the airflow upon the actuator arms54(i.e., windage). In addition where the inner wall88is formed of a porous material, airflow may be redirected towards the center of the disks20,22as well, so as to further mitigate impingement of airflow upon the actuator arms54of the head stack assembly40. Though not shown, in this embodiment, the airflow inlet76need not be open as shown and may be provided with a filter. The porosity of such filter would be preferably course in comparison to that of the outlet filter90.

According to another aspect of the present invention, there is provided the disk drive10. The disk drive10includes the disk drive base16, and a disk, such as disk20, rotatably coupled to the disk drive base16. The disk20includes a disk surface, such as the upper disk surface28, and defines the axis of rotation38. The disk drive10further includes the head stack assembly40rotatably coupled to the disk drive base16adjacent the upper disk surface28. The disk drive10further includes an airflow channeling enclosure, such as the airflow channeling enclosure70, disposed adjacent to and spaced apart from the upper disk surface28. The airflow channeling enclosure70includes the airflow inlet76configured to receive the disk rotation induced airflow therethrough. In this embodiment the airflow inlet76is required to be an open airflow inlet. The airflow channeling enclosure70further includes the airflow channel78extending along the disk surface28from the airflow inlet76. The airflow channeling enclosure70further includes the outer wall80extending along the upper disk surface28from the airflow inlet76and defining the airflow channel78radially interior to the outer wall80with respect to the disk20. The airflow channeling enclosure70further includes the airflow outlet82disposed upstream of the head stack assembly40extending from the outer wall80and the airflow channel78opposite the airflow inlet76for modifying the disk rotation induced airflow passing from the airflow channel78.

As mentioned above, according to this particular aspect of the present invention, the airflow inlet76is required to be an open airflow inlet. In this regard, the term open refers to an absence of any filter or porous material being disposed across the airflow inlet76. Furthermore, according to this particular aspect of the present invention, although the airflow inlet76is shown to be disposed downstream of the head stack assembly40, it is not required to be disposed downstream.

The airflow channeling enclosures70,72,74may take a variety of geometric shapes and sizes. In this embodiment, the airflow channeling enclosures70,72,74each define a generally arced shape. Furthermore, the airflow inlet and outlets76,82may be of various shapes, sizes and angular orientation.

In the embodiment shown, the airflow channeling enclosures70,72,74are supported in a variety of ways. The airflow channeling enclosure70is attached to the cover18. The second plate86of the airflow channeling enclosure70may be adhesively bonded to an underside of the cover18. As seen inFIGS. 1 and 6, the airflow channeling enclosure72which is disposed between the disks20,22is supported by fasteners92. In this regard, the airflow channeling enclosure72is similar in construction as the airflow channeling enclosure70, however the airflow channeling enclosure72includes tabs96which are formed to receive the fasteners92. As further seen inFIG. 1, the airflow channeling enclosure72is spaced apart from the airflow channeling enclosure74with the use of cylindrical spacers94. The airflow channeling enclosure74is directly attached to the disk drive base16with the use of the fasteners92. In this regard, the airflow channeling enclosure74includes tabs98which are also formed to receive the fasteners92.