Swage plate with protruded walls to increase retention torque in hard disk applications

1. Field of the Invention

The present invention relates to a swage mount plate that is used to attach a suspension arm to an actuator arm of a hard disk drive.

2. Background Information

Hard disk drives contain a plurality of heads that are magnetically coupled to the surfaces of magnetic disks which are rotated by a spindle motor. Each head typically includes a write element that can magnetize the disk surface and a read element that can sense the magnetic field of the disk surface. Binary information can be stored and retrieved from the disks by magnetizing and sensing the magnetic fields of the disk surfaces as is known in the art.

Each head typically has an air bearing surface which cooperates with an air flow created by the rotating disks to create an air bearing between the head and the surface of the disk. The air bearing prevents mechanical wear between the head and the disk. It is desirable to minimize the height of the air bearing to maximize the magnetic coupling between the read/write elements and the disks.

When the disk drive is powered down the disks are spun down and the heads land on the disk surfaces. When the disk drive is powered up the disks are again rotated to generate an air flow which creates the air bearings between the heads and the disk surfaces. The creation of the air bearings moves the heads away from the disk surfaces. To allow this movement the heads are typically mounted to a suspension arm which is flexible to become deflected under the force of the air bearing. A head and suspension arm are commonly referred to as a head gimbal assembly (HGA).

The suspension arm is attached to an actuator arm that is pivotally mounted to a base plate of the disk drive. The actuator arm has a voice coil which is coupled to a magnet assembly. The voice coil and magnet assembly are commonly referred to as a voice coil motor (VCM). The voice coil motor can be excited by an electrical circuit(s) to induce a pivotal movement of the actuator arm relative to the base plate. Pivoting the actuator arm moves the heads across the surfaces of the disks. Data is typically stored within annular tracks of the disks. The voice coil motor allows the heads to access the different tracks of the disks.

Each suspension arm is typically attached to a corresponding actuator beam of the actuator arm with a swage mount plate. The swage mount plate has a sleeve that extends through openings in both the suspension arm and the actuator beam. A swage ball is pushed through an inner sleeve opening to expand the sleeves into the actuator beam. The swage plate may have a lip that captures the suspension arm to attach the arm to the actuator beam. The retention force of the swage plate is proportional to the surface area of the sleeve.

It is generally desirable to assemble more disks into a disk drive while minimizing the height of the drive. These criteria may require a reduction in the thickness of the actuator beams and the height of the swage plate sleeves. A shorter sleeve may reduce the retention torque of the swage plate. It would be desirable to provide a swage mount plate which has a higher retention torque per sleeve height than plates of the prior art.

One embodiment of the present invention is a swage mount plate that can be used to attach a suspension arm to an actuator beam of a hard disk drive. The swage mount plate may include a sleeve that can be inserted into corresponding swage openings of the suspension arm and the actuator beam. The swage plate may include at least one flange that extends from said sleeve.

FIG. 1 is a perspective view of an embodiment of a hard disk drive of the present invention;

FIG. 2 is a perspective view of an embodiment of a swage mount plate;

FIG. 3 is a cross-sectional view showing the swage mount plate assembled into the disk drive; and

FIG. 4 is a perspective view of an alternate embodiment of the swage mount plate.

Referring to the drawings more particularly by reference numbers, FIG. 1 shows an embodiment of a hard disk drive 10 of the present invention. The disk drive 10 may include a spindle motor 12 that is mounted to a base plate 14 . The spindle motor 12 rotates a plurality of disks 16 . The disks 16 rotate relative to an actuator arm assembly 18 . The actuator arm assembly 18 includes a plurality of head gimbal assemblies 20 that are attached to actuator beams 22 of an actuator arm 24 . Each head gimbal assembly 20 may include a head 26 that is gimbal mounted to a suspension arm 28 . Each suspension arm 28 is mounted to an actuator beam 22 by a swage mount plate 30 .

FIG. 2 shows an embodiment of a swage mount plate 30 that can be used to attach the suspension arm 28 to the actuator arm 22 . The swage plate 30 may include a sleeve 32 that extends from a lip 34 . The plate 30 may further have a plurality of flanges 36 that extend along a longitudinal axis of the sleeve 32 . Each flange 36 may have a pair of tapered surfaces 38 that intersect at an edge 40 .

FIG. 3 shows the sleeve 32 of a swage mount plate 30 inserted into corresponding swage openings 42 and 44 in a suspension arm 28 and an actuator beam 22 , respectively. A swage ball 46 can be inserted through an opening 48 in the sleeve 32 to push the flanges 36 into the beam 22 . The swage plate 30 is constructed from a material that is harder than the suspension arm 28 so that the flanges 36 are pushed into the arm material. By way of example, the swage plate 30 may be constructed from steel and the arm 28 may be constructed from aluminum. The lip 34 presses the suspension arm 28 onto the actuator beam 29 to connect the components. Providing edges 40 in the flanges 36 provides a surface that can become embedded into the actuator beam 22 to increase the gripping strength of the sleeve 32 and retention torque of the swage plate 30 . The openings 42 , 44 and 48 can be aligned so that the swage ball 46 can swage all of the suspension arms 28 onto all of the actuator beams 22 in one motion.

FIG. 4 shows an alternate embodiment of swage mount plate 30 ′ which has a single annular flange 36 ′ that extends around a circumference of a sleeve 32 ′. The flange 36 ′ may have a pair of tapered surfaces 38 ′ that intersect at an edge 40 ′. The flange 36 ′ can become embedded into an actuator beam when the swage plate 30 ′ is used to attach a suspension arm to the beam. Although one flange 36 ′ is shown and described, it is to be understood that the swage plate 30 ′ may have a plurality of annular flanges 36 ′.

Referring to FIG. 1, each head 26 is magnetically coupled to a disk surface 50 . Each head 24 may include a write element (not shown) and a read element (not shown) that are coupled to an electronic circuit(s) (not shown). The circuit and read/write elements can magnetize and sense the magnetic field of each disk surface 50 to store and retrieve data within the disk drive. The data is typically stored within sectors that extend along annular tracks of the disks 16 . Each head 26 typically includes an air bearing surface which cooperates with an air flow created by the rotating disks 16 to create an air bearing between the head 26 and the disk surface 50 . The air bearing prevents contact and wear between the disks 16 and the heads 28 .

The actuator arm assembly 18 may include a bearing assembly 52 that couples the actuator arm 22 to the base plate 14 . The bearing assembly 52 allows the actuator arm 22 to pivot about the base plate 14 . A voice coil 54 may be attached to the actuator arm 22 . The voice coil 54 may be coupled to a magnet assembly 56 and a driver circuit (not shown). When excited by the driver circuit the voice coil 54 cooperates with the magnet assembly 42 to create a torque that swings the actuator arm 24 relative to the base plate 14 . The pivotal movement of the actuator arm 22 moves the heads 28 across the disk surfaces 50 to access different tracks of the disks 16 .

While certain exemplary embodiments have been described and shown in the accompanying drawings, it is to be understood that such embodiments are merely illustrative of and not restrictive on the broad invention, and that this invention not be limited to the specific constructions and arrangements shown and described, since various other modifications may occur to those ordinarily skilled in the art.