Sloping transition on a ramp of a hard disk drive

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

The present Application for Patent claims priority to U.S. Provisional Application No. 62/056,355, filed Sep. 26, 2014, which is assigned to the assignee of the present application and hereby expressly incorporated by reference herein in its entirety.

BACKGROUND

Description of the Related Art

An HDD is a type of magnetic recording device. An HDD generally includes a spindle, at least one disk of magnetic media mounted on the spindle, a motor configured to spin the spindle and disks, a slider, a head stack assembly (HSA) mounted on the slider configured to slide across the disks reading from and writing to the magnetic media, and a HDD ramp. The HSA generally includes one or more heads that actually read from and write to the disks and a suspension assembly including gimbals that are configured to allow the heads to “float” in close proximity to the disks. When the HDD is not active (e.g., powered off), the head stack assembly is “parked” on the HDD ramp to prevent the heads from contacting the disks.

Two features of a typical HDD ramp are a gimbal limiter and a head separator fin. The portion of the HDD ramp forming the head separator fin is typically thinner than the portion of the HDD ramp forming the gimbal limiter. The transition between the head separator fin portion of a HDD ramp and the gimbal limiter portion of a HDD ramp generally consists of a step forming angles of approximately 90 degrees with the head separator fin and gimbal limiter.

Under normal conditions, the gimbal does not touch the gimbal limiter while the head stack assembly is parked on the ramp, but instead sits above the gimbal limiter, separated from the gimbal limiter by a short distance, for example 0.22 mm. When an HDD experiences a physical shock (e.g., the HDD is dropped or struck by an object) while the HDD is not operating, this is referred to a non-operational or non-op shock event. In a non-op shock event, the gimbal may make contact with the gimbal limiter, which restricts the motion of the gimbal.

However, in certain cases it may be possible for the gimbal to become lodged against the step between the gimbal limiter portion of the HDD ramp and the head separator fin portion of the HDD ramp in a non-op shock event. During a non-op shock event, the head gimbal assembly (HGA) and gimbal can both oscillate, and the tip of the gimbal may retract beyond the edge of the step between the gimbal limiter portion of the HDD ramp and the head separator fin portion of the HDD ramp. If the gimbal becomes lodged or otherwise sticks beyond the edge of the step, portions of the suspension may be permanently deformed, and the drive may become unusable.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the present disclosure can be understood in detail, a more particular description of the disclosure may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this disclosure and are therefore not to be considered limiting of its scope, for the disclosure may admit to other equally effective embodiments.

FIG. 1 is a schematic illustration of an HDD according to an embodiment of the present disclosure.

FIG. 2 illustrates an HDD ramp, according to embodiments of the present disclosure.

FIG. 3 illustrates an HDD ramp, according to embodiments of the present disclosure.

FIG. 4 illustrates an HDD ramp, according to embodiments of the present disclosure.

FIG. 5 illustrates portions of a head stack assembly and HDD ramp, according to embodiments of the present disclosure.

FIG. 6 illustrates an operation for preventing damage to a head gimbal assembly of an HDD, according to aspects of the present disclosure.

To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements disclosed in one embodiment may be beneficially utilized on other embodiments without specific recitation.

DETAILED DESCRIPTION

The present disclosure generally relates to a chamfer on a ramp of a hard disk drive (HDD) at a transition from a gimbal limiter portion to a head separator fin portion of the HDD ramp.

FIG. 1 is a schematic illustration of a magnetic recording device, such as an HDD 100, according to one embodiment of the present disclosure. The HDD 100 includes at least one magnetic recording medium, such as a disk 102 that is supported on a spindle 104. A motor causes the spindle 104, and hence the disk 102, to rotate. One or more magnetic heads 106 are mounted on a slider 108 and move over the disks 102 to read and write information from and to the disks 102. The heads 106 ride on an air bearing in close proximity to the disks 102 during read and write operations. The slider 108 is coupled to an actuator 110 by a suspension 112. The suspension 112 provides a slight spring force which biases the slider 108 towards the disk surface. Each actuator 110 is attached to an actuator means 114 that controls the movement of the head 106 relative to the disk 102. A HDD ramp 116 is positioned such that when the actuator 110 rotates the slider 108 and head 106 away from the disk 102, the heads and slider can “park” on the HDD ramp 116.

FIG. 2 illustrates a front view of a prior art HDD ramp 200. The HDD ramp 200 may be made of plastic (e.g., polytetrafluoroethylene (PTFE)) or other suitable materials. The HDD ramp 200 is mounted to the HDD at 202. The HDD ramp 200 may be mounted to the HDD by means of screws, for example. The gimbal limiter portions of the HDD ramp are shown at 204. The head separator fin portions of the HDD ramp are shown at 206. While the HDD ramp is illustrated with two gimbal limiters and two head separator fins, other numbers of gimbal limiters and head separator fins are possible.

As described above with reference to FIG. 1, when the actuator 110 rotates the slider 108 and heads 106 away from the disks 102 of the HDD 100, the heads and slider can “park” on the HDD ramp 116 or 200. Gimbals (not shown in FIG. 1) at the tip of the heads “park” in close proximity to the gimbal limiter portion 204 of the HDD ramp 200. The head separator fin portion 206 of the HDD ramp 116 or 200 separates the various heads from each other while they are parked.

The HDD ramp 200 shown in FIG. 2 is similar to typical ramps, in that the transitions 208 between the head separator fin portions 206 and the gimbal limiter portions 204 are steps that are approximately perpendicular to the surfaces of the head separator fin portions 206 and the gimbal limiter portions 204. In other words, each step at the transition from the corresponding fin separator portion of the HDD ramp to the corresponding gimbal limiter portion of the HDD ramp forms angles of approximately 90 degrees with both the fin separator portion of the HDD ramp and the gimbal limiter portion of the HDD ramp.

FIG. 3 illustrates a front view of an HDD ramp 300, according to one embodiment of the present disclosure. The HDD ramp 300 may be made of plastic (e.g., polytetrafluoroethylene (PTFE)) or other suitable materials. The HDD ramp 300 is mounted to the HDD at 202. The HDD ramp 300 may be mounted to the HDD by means of screws, for example. While the HDD ramp 300 is illustrated with two gimbal limiters and two head separator fins, other numbers of gimbal limiters and head separator fins are possible. Chamfers at the transition from the gimbal limiter portions 204 to the head separator fin portions 206 of the HDD ramp are shown at 302. The chamfers at 302 may be disposed at an angle α to the head separator fin of approximately 120 to 150 degrees, for example 130 to 140 degrees, for example 135 degrees. That is, an axis parallel to the surface of the transition may form an angle with an axis parallel to the surface of the head separator fin (e.g., an interior angle) of approximately 30 to 60 degrees, for example 40 to 50 degrees, for example, 45 degrees. By chamfering the gimbal limiter portion 204 at the edge where the HDD ramp 300 transitions from the gimbal limiter portion 204 to the head separator fin portion 206, the tip of a gimbal may be prevented from catching on the step between the gimbal limiter portion 204 and the head separator fin portion 206. By preventing the tip of the gimbal 302 from catching on the step between the gimbal limiter portion 204 and the head separator fin portion 206, damage to the HDD suspension associated with some non-op shock events may be prevented.

FIG. 4 illustrates a top view of an HDD ramp 300, according to one embodiment of the present disclosure. As illustrated in FIG. 4, the width of the chamfer 302 varies with the distance between the surfaces of the gimbal limiter portion 204 of the HDD ramp and the fin separator portion 206 of the HDD ramp.

FIG. 5 illustrates a front view of portions of an HDD head 106 and HDD ramp 300, according to one embodiment of the present disclosure. The view of the HDD ramp in FIG. 5 is taken from the same point of view as that of FIG. 3, but the HDD head 106 is not shown in FIG. 3. While the HDD ramp 300 is illustrated with two gimbal limiters and two head separator fins, other numbers of gimbal limiters and head separator fins are possible. The HDD head 106 is shown in the “parked” position in relation to the HDD ramp 300. The tip of a gimbal is shown at 502. A chamfer at the transition from the gimbal limiter portion 204 to the head separator fin portion 206 of the HDD ramp is shown at 302. By chamfering the gimbal limiter portion 204 at the edge where the HDD ramp 300 transitions from the gimbal limiter portion 204 to the head separator fin portion 206, the tip 502 of the gimbal may be prevented from catching on the transition between the gimbal limiter portion 204 and the head separator fin portion 206. By preventing the tip 502 of the gimbal from catching on the transition between the gimbal limiter portion 204 and the head separator fin portion 206, damage to the HDD suspension associated with some non-op shock events may be prevented.

FIG. 6 sets forth an operation 600 for preventing damage to a head gimbal assembly of an HDD, according to aspects of the present disclosure. The operation 600 may be performed by an HDD 100 as illustrated in FIG. 1, equipped with a HDD ramp 300 as illustrated in FIG. 3, for example. Operation 600 may commence at 602 by parking a head of an HDD on a ramp of the HDD, wherein the HDD ramp comprises a ramp body having a head separator fin, a gimbal limiter adjacent to the head separator fin which is thicker than the head separator fin, and a first chamfer at a transition between a first surface of the gimbal limiter and a first surface of the head separator fin.

As used herein, a phrase referring to “at least one of” a list of items refers to any combination of those items, including single members. As an example, “at least one of: a, b, or c” is intended to cover a, b, c, a-b, a-c, b-c, and a-b-c.

Moreover, the term “or” is intended to mean an inclusive “or” rather than an exclusive “or.” That is, unless specified otherwise or clear from the context, the phrase, for example, “X employs A or B” is intended to mean any of the natural inclusive permutations. That is, for example the phrase “X employs A or B” is satisfied by any of the following instances: X employs A; X employs B; or X employs both A and B. In addition, the articles “a” and “an” as used in this application and the appended claims should generally be construed to mean “one or more” unless specified otherwise or clear from the context to be directed to a singular form. A phrase referring to “at least one of” a list of items refers to any combination of those items, including single members. As an example, “at least one of: a, b, or c” is intended to cover: a, b, c, a-b, a-c, b-c, and a-b-c.

The methods disclosed herein comprise one or more steps or actions for achieving the described method. The method steps and/or actions may be interchanged with one another without departing from the scope of the claims. In other words, unless a specific order of steps or actions is specified, the order and/or use of specific steps and/or actions may be modified without departing from the scope of the claims.

While the foregoing is directed to embodiments of the present disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.