JP2010129108A - Magnetic disk device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a disk device that has an increased disk format capacity and moves a head slider to a track direction even when an actuator arm vertically vibrates. <P>SOLUTION: An HSA 130 includes a suspension 133 supporting the head slider 135, and the actuator arm 131 supporting the suspension 133 and having an angle with respect to the head slider 135 and the suspension 133. The actuator arm 131 includes a reinforcement 132 that is continuously formed from a body 131a along a second side opposite to a first side facing a disk in a state of being retracted from a disk and has a predetermined length in substantially parallel to the second side. The body 131a is disposed at a side opposite to an end supporting the suspension 133 of the actuator arm 131. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a magnetic disk device.

  A hard disk drive (hereinafter referred to as “HDD”) includes, for example, a magnetic disk on which information is recorded, a head slider including a recording / reproducing element for reading and writing information provided facing the magnetic disk, and a head slider. A head stack assembly (Head Stack Assembly; hereinafter referred to as “HSA”) that is held and rotated to a predetermined position on the magnetic disk is provided. The HSA is configured by stacking a head gimbal assembly (hereinafter referred to as “HGA”) that holds a head slider on a bearing portion that serves as a rotational drive shaft.

  As shown in FIG. 10, the HSA 10 used in the conventional HDD includes an actuator arm 11, a suspension 13 supported on one end side of the actuator arm 11, and a head slider 15 supported on the suspension 13. An insertion hole through which the pivot 14 serving as the rotation shaft of the HSA 10 is inserted is formed in the body portion 11a located on the opposite side to the end portion that supports the suspension 13 of the actuator arm 11.

  Further, a drive for rotating the HSA 10 by acting with a magnet and a yoke provided on the base (reference numeral 2 in FIG. 11) side of the HDD at a position opposite to the end portion supporting the suspension 13 with respect to the pivot 14. A VCM coil for generating force is provided. An FPC (Flexible Printed Circuit) 17 that transmits a signal from the recording / reproducing element of the head slider 15 and a drive current to the VCM coil 16 is attached to one side surface extending in the longitudinal direction of the actuator arm 11. In such an HSA 10, the actuator arm 11 is provided on the same straight line with respect to the suspension 15 and the head slider 15 as shown in FIG. 10.

  As shown in FIG. 11, the HDD 1 including the HSA 10 moves a head slider 15 including a recording / reproducing element onto the disk 5 rotated by the spindle motor 3 to record / reproduce information with respect to the disk 5. I do. For example, when information is recorded on the disk 5, when the head slider 15 is positioned on the innermost track or the outermost track of the information recording area of the disk 5, as shown in FIG. The recording / reproducing element of the head slider 15 has a predetermined angle with respect to the tangential direction of the disk 5. When this angle (skew angle) increases, as shown in FIG. 12, the width of data recorded on the track 5a (MWW: Magnetic Write Width) by the recording / reproducing element 15a increases, and data that can be recorded on the disc 5 There was a problem that the capacity was reduced.

  In order to solve such a problem, as shown in FIG. 13, an HSA 20 having a suspension 23 and a head slider 25 having a predetermined mounting angle with respect to the actuator arm 21 has been proposed (for example, patents). Reference 1). Similar to the HSA 10 shown in FIG. 10, the HSA 20 also includes an actuator arm 21, a suspension 23, and a head slider 25, and the body portion 21 of the actuator arm 21 is provided with a pivot 24 serving as a rotation shaft. . The HSA 20 is provided with a VCM coil 26 that acts on a magnet and a yoke provided on the base (reference numeral 2 in FIG. 14) side of the HDD to generate a driving force for rotating the HSA 20, and an FPC 27.

  When information is recorded / reproduced on / from the disk 5 using the HSA 20 having the suspension 23 and the head slider 25 having a predetermined mounting angle with respect to the actuator arm 21, the HSA 10 having the shape shown in FIG. Compared with the case where the head slider 25 is positioned, the skew angle when the head slider 25 is positioned on the innermost track or the outermost track of the information recording area of the disk 5 can be reduced. That is, the data capacity that can be recorded on the disk 5 can be increased. In addition, by reducing the skew angle, the flying height of the head slider 25 at that position can be stabilized.

Japanese Patent Laid-Open No. 06-243624

  However, when the HSA 20 having the shape shown in FIG. 13 is used, there is a problem that the head slider 25 vibrates in the off-track direction when the actuator arm 21 vibrates in the vertical direction under the influence of external vibration or the like. .

  That is, in the case of the HSA 10 in which the actuator arm 11, the suspension 13 and the head slider 15 are provided in the same straight line, as shown in FIG. 15, when the actuator arm 11 vibrates in the vertical direction, the head slider 15 moves along the track direction. Moving. On the other hand, in the case of the HSA 20 in which the suspension 23 and the head slider 25 are provided with a predetermined mounting angle with respect to the actuator arm 21, as shown in FIG. 16, when the actuator arm 21 vibrates in the vertical direction, the head slider 25 Will move in the off-track direction. In this case, the displacement with respect to the servo signal is increased, and the position error signal is increased.

  Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to increase the disk format capacity and to move the head slider in the track direction even when the actuator arm vibrates in the vertical direction. It is an object of the present invention to provide a new and improved magnetic disk apparatus which can be moved to a disk.

  In order to solve the above-described problems, according to an aspect of the present invention, a disk that is a recording medium, a rotation drive unit that rotates the disk, a base that supports the rotation drive unit, and information recording / reproduction with respect to the disk There is provided a magnetic disk device including a head stack assembly that supports a head slider including a recording / reproducing element for rotating to a predetermined position on the disk. The head stack assembly includes a suspension that supports the head slider, and an actuator arm that supports the suspension and is provided at an angle with respect to the head slider and the suspension. The actuator arm is positioned on the opposite side of the end supporting the suspension of the actuator arm along the second side opposite to the first side facing the disk in a state of being retracted from the disk. A reinforcing portion having a predetermined length in a direction substantially parallel to the second side and formed continuously from the portion.

  According to the present invention, the actuator arm is provided with the reinforcing portion formed continuously with the body portion along the second side opposite to the first side facing the disk. As a result, the difference in rigidity generated in the actuator arm can be reduced, and the head slider can be moved in the track direction when the actuator arm vibrates in the vertical direction. Further, since the actuator arm can be provided at an angle with respect to the head slider and the suspension, the disk format capacity can be increased.

  Here, the length of the reinforcing portion can be 5 to 50% of the length of the actuator arm. Further, the width of the reinforcing portion, which is the length in the direction perpendicular to the second side, can be 5 to 15% of the width of the flat portion of the actuator arm. The height of the reinforcing portion, which is the length of the actuator arm in the rotation axis direction, can be 50 to 150% of the thickness of the flat portion of the actuator arm.

  The reinforcing portion can be formed in a rib shape that protrudes substantially vertically from the flat portion of the actuator arm. Further, the height of the reinforcing portion may be formed so as to increase linearly or curvedly from the first side of the actuator arm toward the second side. Furthermore, the height of the reinforcing portion may be increased linearly or curvedly from the suspension side of the actuator arm toward the body portion.

  As described above, according to the present invention, it is possible to provide a magnetic disk device capable of increasing the disk format capacity and moving the head slider in the track direction even when the actuator arm vibrates in the vertical direction. it can.

  Exemplary embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In addition, in this specification and drawing, about the component which has the substantially same function structure, duplication description is abbreviate | omitted by attaching | subjecting the same code | symbol.

<Configuration of magnetic disk device>
First, a magnetic disk device according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a plan view showing a schematic configuration of an HDD 100 that is a magnetic disk device according to the present embodiment. FIG. 2 is a perspective view showing the HSA 130 according to the present embodiment.

  The magnetic disk device according to the present embodiment is, for example, an HDD 100, and as shown in FIG. 1, a disk 105 that is a data recording medium, a base 110, a spindle motor 120 that holds and rotates the disk 105, and a disk And HSA 130 for rotating and moving a head slider 135 including a recording / reproducing element for recording data on 105 and / or reproducing data recorded on the disk 105.

  In addition to supporting the spindle motor 120, the base 110 is, for example, an actuator that rotates an HSA 130, which will be described later, or a stopper that is an impact buffering mechanism that limits the operating range of the actuator to prevent contact between the head slider 135 and other members. A plurality of mechanical parts are assembled.

  The spindle motor 120 is a rotational drive unit that rotates the disk 105 and is supported by the base 110. The spindle motor 120 is provided, for example, on a rotating shaft that is the rotation center of the spindle motor 120, a bearing provided around the rotating shaft, a hub that holds the disk 105 via the bearing, and an outer peripheral portion of the hub. It is comprised from a magnet rotor and the stator part which consists of a some stator coil row | line | column.

  The HSA 130 is a mechanism that supports a head slider 135 including a recording / reproducing element that records and / or reproduces data on the disk 105 and rotates it to a predetermined position on the disk 105. As shown in FIG. 2, the HSA 130 includes an actuator arm 131, a suspension 133, a head slider 135, a pivot 140, an FPC 150, and a VCM coil 160.

  As shown in FIG. 2, the actuator arm 131 according to the present embodiment includes a body portion 131a in which a through hole 134 to which the pivot 140 is attached is formed, and a flat portion 131b connected to the body portion 131a. A suspension 133 is attached to the flat portion 131b. Further, the flat portion 131b of the actuator arm 131 has a reinforcing portion 132 that is formed continuously from the body portion 131a along the side opposite to the side facing the disk 105 and extending in the longitudinal direction of the actuator arm 131. It is formed. The reinforcing part 132 adjusts the difference in rigidity generated in the actuator arm 131.

  The pivot 140 is a bearing member that rotatably supports the actuator arm 131 and is inserted into a through hole 134 formed in the body portion 131 a of the actuator arm 131. The FPC 150 is a substrate that transmits a signal from the recording / reproducing element of the head slider 135 and a drive current to the VCM coil 160, and is attached to one side surface of the actuator arm 131 in the longitudinal direction. The VCM coil 160 works with a magnet and a yoke provided on the base 110 side to generate a driving force that rotates the HSA 130.

  In such HDD 100, when data is recorded and / or reproduced on the disk 105, the HSA 130 is rotated by an actuator constituted by a voice coil motor (VCM) and the head slider 135 is moved to a predetermined position on the disk 105. Move on track. When data recording and / or reproduction is not performed, the HSA 130 is driven by an actuator, and the head slider 135 is retracted from the disk 105.

  The schematic configuration of the HDD 100 according to the present embodiment has been described above. In the HDD 100 according to the present embodiment, the actuator arm 131 constituting the HSA 130 is provided with the reinforcing portion 132 to adjust the difference in rigidity generated in the actuator arm 131. Hereinafter, based on FIGS. 3-7, the reinforcement part 132 of the actuator arm 131 concerning this embodiment is demonstrated in detail. FIG. 3 is a plan view showing the actuator arm 131 according to the present embodiment. FIG. 4 is a side view showing the actuator arm 131 according to the present embodiment. FIG. 5 is an explanatory diagram showing the relationship between the moving angle and the head slider 135. FIG. 6 is a graph showing a simulation result of the relationship between the length of the reinforcing portion 132 of the actuator arm 131 and the movement angle according to the present embodiment. FIG. 7 is a graph showing a simulation result regarding the relationship between the height of the reinforcing portion of the actuator arm 131 and the movement angle according to the present embodiment.

<Configuration of actuator arm reinforcement>
As described above, the actuator arm 131 according to the present embodiment includes the reinforcing portion 132 that adjusts the difference in rigidity generated in the actuator arm 131. Here, when the actuator arm 131 according to the present embodiment is compared with the conventional actuator arm 21 shown in FIG. 13, the thickness of the flat portion that supports the suspension 23 of the conventional actuator arm 21 is formed uniformly. . Here, the thickness of the flat portion refers to the length of the HSA 20 in the rotation axis direction.

  In such an actuator arm 21, the rigidity of the other side located on the side opposite to the side facing the disk 5 out of the pair of sides extending in the longitudinal direction of the actuator arm 21 is on the side facing the disk 5. It has become clear that it is smaller than the side stiffness. This is because the shape of the actuator arm 21 is asymmetric. If a difference occurs in the rigidity of these sides, as described above, in the bending mode in which the actuator arm 21 vibrates in the vertical direction, the head slider 25 vibrates in the off-track direction, and the displacement with respect to the servo signal increases. Arise.

  Therefore, in the HSA 130 according to the present embodiment, the suspension 133 and the head slider 135 are arranged at an angle with respect to the actuator arm 131 in order to reduce the skew angle over the entire disk surface, and the difference in rigidity generated in the actuator arm 131 is also determined. In order to reduce this, the reinforcing portion 132 is formed.

  The reinforcing portion 132 is formed continuously from the body portion 131 a along a side 131 e that extends in the longitudinal direction of the actuator arm 131 and is opposite to the side 131 d facing the disk 105. The side 131d facing the disk 105 refers to a side facing the disk 105 when the head slider 135 is retracted from the disk 105, as shown in FIG. As shown in FIG. 2, the reinforcing portion 132 according to the present embodiment is formed in a rib shape protruding vertically from the flat portion 131 b.

  Here, by adjusting the length L1 of the reinforcing portion 132, the width W1 of the reinforcing portion 132, and the height H of the reinforcing portion 132, the actuator arm 131 on the side 131e opposite to the side 131d facing the disk 105 is adjusted. Stiffness can be adjusted. The length L1 of the reinforcing portion 132 is a length in a direction substantially parallel to the side 131e of the actuator arm 131, as shown in FIG. As shown in FIG. 3, the width W1 of the reinforcing portion 132 refers to the length from the side 131e to the side facing the disc 105 of the reinforcing portion 132 extending substantially parallel to the side 131e. Further, the height H of the reinforcing portion 132 means the length from the flat portion 131b of the actuator arm 131 to the upper surface of the reinforcing portion 132, that is, the length in the z-axis direction, as shown in FIG.

  In the actuator arm 131 of the HSA 130 according to the present embodiment, the length L1 of the reinforcing portion 132 is set to about 5 to 50% of the length L0 of the actuator arm, and the width W1 of the reinforcing portion 132 is set to the flat portion 131b of the actuator arm 131. Is set to about 5 to 15% of the maximum width W0. Further, the height H of the reinforcing portion 132 is set to about 50 to 150% of the thickness of the flat portion 131b of the actuator arm 131. By determining the shape of the reinforcing portion 132 in this manner, the difference in rigidity that has occurred in the actuator arm 131 can be reduced, and the vibration of the head slider 135 can be controlled to be in the track direction of the disk 105.

<Relationship between shape of reinforcement and angle of head slider with respect to track direction>
Here, for the length L1 of the reinforcing portion 132 and the width W1 of the reinforcing portion 132, a simulation was performed on the relationship between each value and the movement angle θ. In the simulation, when the actuator 131 is vibrated up and down by changing the length L1 of the reinforcing portion 132 or the width W1 of the reinforcing portion 132, the moving angle θ that is an angle formed by the head slider 135 with respect to the track direction of the disk 105 is set. The change in size was verified. As shown in FIG. 5, when the head slider 135 moves in the positive y-axis direction with reference to the position when the head slider 135 is substantially parallel to the track direction of the disk 105 (the position indicated by reference numeral 135a in FIG. 5). ) Is moved in the positive direction, and when the head slider 135 is moved in the negative y-axis direction (position 135b in FIG. 5) is moved in the negative direction.

  First, the relationship between the length L1 of the reinforcing part 132 and the movement angle θ will be described. In the simulation, the movement angle θ when the length L1 of the reinforcing portion 132 was changed was calculated for two types of actuator arms (arm shape 1 and arm shape 2) having the shape shown in FIG. When the movement angle θ is zero, the head slider 135 is parallel to the tangent to the disk 105. At this time, the width W1 of the reinforcing portion 132 of the two types of actuator arms was 10% of the width of the actuator arm, and the height H of the reinforcing portion 132 was the same as the thickness of the flat portion 131b. The angle formed by the actuator arm 131, the suspension 133, and the head slider 135 is larger in the arm shape 2 than in the arm shape 1.

  The result of this simulation is shown in FIG. The horizontal axis indicates the ratio of the length L1 of the reinforcing portion 132 to the length L0 of the actuator arm 131, and the vertical axis indicates the movement angle θ. As shown in FIG. 6, it can be seen that both the arm shape 1 and the arm shape 2 change the movement angle θ greatly when the length L1 of the reinforcing portion 132 is changed. As described above, in order to control the movement of the head slider 135 due to the vertical vibration of the actuator arm 131 to be in the track direction, the magnitude of the movement angle θ is desirably as small as possible. Therefore, it can be seen from the range of the allowable movement angle θ that the length L1 of the reinforcing portion 132 should be set to about 5 to 50% of the length L0 of the actuator arm 131.

  Next, the relationship between the height H of the reinforcing portion 132 and the movement angle θ will be described. In the simulation, similarly to the above-described simulation for the length L1 of the reinforcing portion 132, the height H of the reinforcing portion 132 is set for two types of actuator arms (arm shape 1 and arm shape 2) having the shape shown in FIG. The moving angle θ when changed was calculated. In this case as well, when the movement angle θ is zero, the head slider 135 is parallel to the track direction of the disk 105. At this time, the length L1 of the reinforcing portion 132 of the two types of actuator arms was 50% of the length L0 of the actuator arm 131, and the width W1 of the reinforcing portion 132 was 10% of the width of the actuator arm.

  The result of this simulation is shown in FIG. The horizontal axis indicates the ratio of the height H of the reinforcing portion 132 to the height of the flat portion 131b of the actuator arm 131, and the vertical axis indicates the movement angle θ. As shown in FIG. 7, it can be seen that both the arm shape 1 and the arm shape 2 have little influence on the magnitude of the movement angle θ even if the height H of the reinforcing portion 132 is changed. In consideration of the result and the configuration of the HDD, the height H of the reinforcing portion 132 is set to about 50 to 150% of the thickness of the flat portion 131b of the actuator arm 131.

  Similarly to the height H of the reinforcing portion 132, the width W1 of the reinforcing portion 132 has little influence on the magnitude of the movement angle θ even if the size of the width W1 is changed. Therefore, the width W1 of the reinforcing portion 132 is also set to about 5 to 15% of the maximum width W0 of the flat portion 131b of the actuator arm 131 in consideration of the configuration of the HDD and the like.

  Thus, by determining the size and shape of the reinforcing portion 132 of the actuator arm 131, the movement of the head slider 135 due to the vertical vibration of the actuator 131 can be controlled in the track direction of the disk 105.

<Reinforcement shape>
Moreover, although the reinforcement part 132 of the actuator arm 131 concerning this embodiment was formed in the rib shape, another shape may be sufficient. For example, the cross-sectional shape of the actuator arm 131 shown in FIG. 3 taken along the line AA can be a shape shown in FIGS. 8A to 8E. For example, the reinforcing portion 132 can be provided perpendicular to the flat portion 131b as shown in FIG. 8A. Further, as shown in FIG. 8B, the reinforcing portion 132 may be formed so as to increase linearly from the side 131d facing the disk 105 toward the opposite side 131e, as shown in FIG. 8C. The side 131d side of the actuator arm 131 is a flat portion 131b, and may be formed so as to increase linearly from a predetermined position (for example, a central portion) of the actuator arm 131 toward the side 131e.

  Further, as shown in FIG. 8D, the reinforcing portion 132 may be formed so as to be curvilinearly raised from the side 131d facing the disk 105 toward the opposite side 131e, as shown in FIG. 8E. The side 131d side of the actuator arm 131 is a flat portion 131b, and may be formed so as to increase in a curve from a predetermined position (for example, a central portion) of the actuator arm 131 toward the side 131e.

  On the other hand, the cross-sectional shape of the actuator arm 131 shown in FIG. 3 taken along the line BB can be as shown in FIGS. 9A to 9C. For example, as shown in FIG. 9A, the reinforcing portion 132 can be provided perpendicular to the flat portion 131c. Further, as shown in FIG. 9B, the reinforcing portion 132 is a flat portion 131c on the side where the suspension 133 of the actuator arm 131 is attached, and from the predetermined position (for example, the central portion) of the actuator arm 131 to the body portion 131a side. You may form so that it may become linearly high toward it. Further, as shown in FIG. 9C, the reinforcing portion 132 is a flat portion 131c on the side where the suspension 133 of the actuator arm 131 is attached, and from the predetermined position (for example, the central portion) of the actuator arm 131 to the body portion 131a side. You may form so that it may become high curvilinearly.

  The HDD 100 according to the embodiment of the present invention has been described above. According to the present embodiment, the reinforcing portion 132 formed continuously from the body portion 131a is provided along the side 131e opposite to the side 131d facing the disk 105 of the actuator arm 131. Thus, the suspension 133 and the head slider 135 are provided at an angle with respect to the actuator arm 131, whereby the disk format amount can be increased, and the movement angle θ of the head slider 135 due to the vertical vibration of the actuator arm 131 is set. Can be small. Therefore, an increase in position error signal can be prevented.

  The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to such examples. It is obvious that a person having ordinary knowledge in the technical field to which the present invention pertains can come up with various changes or modifications within the scope of the technical idea described in the claims. Of course, it is understood that these also belong to the technical scope of the present invention.

It is a top view which shows schematic structure of HDD concerning embodiment of this invention. It is a perspective view which shows HSA concerning the embodiment. It is a top view which shows the actuator arm concerning the embodiment. It is a side view which shows the actuator arm concerning the embodiment. It is explanatory drawing which shows the relationship between a movement angle and a head slider. It is a graph which shows the simulation result about the relationship between the length of the reinforcement part of the actuator arm concerning the same embodiment, and a movement angle. It is a graph which shows the simulation result about the relationship between the height of the reinforcement part of the actuator arm concerning the embodiment, and a movement angle. It is explanatory drawing which shows an example of the shape of the actuator arm in the AA cutting line of FIG. It is explanatory drawing which shows the other example of the shape of the actuator arm in the AA cutting line of FIG. It is explanatory drawing which shows the other example of the shape of the actuator arm in the AA cutting line of FIG. It is explanatory drawing which shows the other example of the shape of the actuator arm in the AA cutting line of FIG. It is explanatory drawing which shows the other example of the shape of the actuator arm in the AA cutting line of FIG. It is explanatory drawing which shows an example of the shape of the actuator arm in the BB cutting line of FIG. It is explanatory drawing which shows the other example of the shape of the actuator arm in the BB cutting line of FIG. It is explanatory drawing which shows the other example of the shape of the actuator arm in the BB cutting line of FIG. It is a top view which shows the conventional HSA. It is a top view which shows HDD provided with HSA shown in FIG. It is explanatory drawing explaining the relationship between a skew angle and the data amount recorded on a disc. It is a top view which shows other conventional HSA. It is a top view which shows HDD provided with HSA shown in FIG. FIG. 11 is an explanatory diagram for explaining the movement of the head slider when the actuator arm vibrates in the vertical direction for the HSA shown in FIG. 10. It is explanatory drawing explaining the motion of a head slider when an actuator arm vibrates up and down about HSA shown in FIG.

Explanation of symbols

100 Hard disk drive (HDD)
105 disks 130 HSA
131 Actuator arm 131a Body part 132 Reinforcement part 133 Suspension 134 Through hole 135 Head slider 140 Pivot 150 FPC
160 VCM coil

Claims (9)

A disc as a recording medium;
A rotation drive unit for rotating the disk;
A base that supports the rotation drive unit;
A head stack assembly that supports a head slider including a recording / reproducing element for recording / reproducing information with respect to the disk and rotates the disk to a predetermined position on the disk;
With
The head stack assembly includes:
A suspension for supporting the head slider;
An actuator arm that supports the suspension and is provided at an angle with respect to the head slider and the suspension;
Have
The actuator arm is on the opposite side of the end supporting the suspension of the actuator arm along a second side opposite to the first side facing the disk in a state of being retracted from the disk. A magnetic disk drive, comprising: a reinforcing portion formed continuously from a positioned body portion and having a predetermined length in a direction substantially parallel to the second side.   The magnetic disk device according to claim 1, wherein a length of the reinforcing portion is 5 to 50% of a length of the actuator arm.   3. The magnetism according to claim 1, wherein a width of the reinforcing portion which is a length in a direction perpendicular to the second side is 5 to 15% of a width of a flat portion of the actuator arm. Disk unit.   The height of the reinforcing portion, which is the length of the actuator arm in the rotation axis direction, is 50 to 150% of the thickness of the flat portion of the actuator arm. Magnetic disk unit.   The magnetic disk device according to claim 1, wherein the reinforcing portion is formed in a rib shape that protrudes substantially perpendicularly from a flat portion of the actuator arm.   5. The magnetic disk device according to claim 1, wherein the height of the reinforcing portion increases linearly from the first side of the actuator arm toward the second side. 6.   5. The magnetic disk device according to claim 1, wherein a height of the reinforcing portion increases in a curved manner from the first side to the second side of the actuator arm.   The magnetic disk device according to claim 1, wherein the height of the reinforcing portion increases linearly from the suspension side of the actuator arm toward the body portion. 8. The magnetic disk device according to claim 1, wherein the height of the reinforcing portion increases in a curved manner from the suspension side of the actuator arm toward the body portion.

Images