BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram showing a state of a load/unload type magnetic disk apparatus from which an upper cover is detached;
FIG. 2 is a schematic diagram showing a structure of a tip end of an arm shown in FIG. 1;
FIG. 3 is an enlarged plan view of a ramp and a tip end of the arm of the magnetic disk apparatus shown in FIG. 1;
FIG. 4 is a perspective view of the ramp;
FIG. 5 is a schematic plan view showing a state of a load/unload type magnetic disk apparatus of a first embodiment of the present invention from which an upper cover is detached;
FIG. 6 is an enlarged plan view of a ramp and a tip end of an arm of the magnetic disk apparatus shown in FIG. 5;
FIG. 7 is a perspective view of the ramp shown in FIG. 6;
FIG. 8 is a diagram showing results of vibration measurement in a comparative example and the embodiment of the invention;
FIG. 9 is a schematic diagram showing a state of a magnetic disk apparatus of a second embodiment of the present invention from which an upper cover is detached;
FIG. 10 is a partial enlarged perspective view a ramp and a slit shroud of the magnetic disk apparatus shown in FIG. 9;
FIG. 11 is a sectional view of the ramp and the slit shroud shown in FIG. 10 taken along the longitudinal direction of the arm; and
FIG. 12 is a sectional perspective view of the cross section shown in FIG. 11 as viewed from a diagonal direction.
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be explained below.
FIG. 5 is a schematic plan view showing a state of a load/unload type magnetic disk apparatus of a first embodiment of the present invention from which an upper cover is detached.
A magnetic disk apparatus 10B shown in FIG. 5 is different from the magnetic disk apparatus shown in FIG. 1 only in shape of the ramp. Therefore, common elements are shown with the same symbols as those in FIG. 1, and redundant explanation will be omitted.
FIG. 6 is an enlarged plan view of a ramp 20B and a tip end of an arm 15 of the magnetic disk apparatus 10B shown in FIG. 5. FIG. 7 is a perspective view of the ramp 20B.
As compared with the magnetic disk apparatus 10A explained with reference to FIGS. 1 to 4, the structure of the arm (see FIG. 2) is the same, and the structure of the ramp is different.
The ramp 20B of the magnetic disk apparatus 10B of this embodiment includes an airflow control plate 22 widening from a tongue 21 toward a rotation shaft 14 of the arm 15 (see FIG. 5) as shown in FIGS. 6 and 7.
As shown in FIG. 6, a side surface of the airflow control plate 22 on the side of the magnetic disk 12 is opposed to a side surface of the magnetic disk 12, and the airflow control plate 22 extends such that a constant gap c is formed between the airflow control plate 22 and the side surface of the magnetic disk 12.
A thickness t of the airflow control plate 22 shown in FIG. 7 is the same as a thickness of the magnetic disk 12, and is also position at the same level (in a direction perpendicular to a paper sheet of FIG. 5) as the level of the magnetic disk 12. Therefore, the front and back surfaces of the airflow control plate 22 are respectively flush with the front and back surfaces of the magnetic disk 15.
The airflow control plate 22 has a shape which is further widened while including a region opposed to the entire region of a slider 132 (see FIG. 2) when a horn 153 of a tip end of the arm 15 is supported by the ramp 20B in an unload state, and has a shape where a portion toward a rotation shaft 14 (see FIG. 5) of the arm 15 is wider than the side of a gimbal 131 facing the rotation shaft 14 (see FIG. 2). With this, the airflow in a region through which the air passes at the time of loading and unloading of the magnetic head is stabilized, and the load/unload operation of the magnetic head is stabilized.
FIG. 8 shows measurement results of vibration of a comparative example (part (A) of FIG. 8) and the embodiment (part (B) of FIG. 8) of the invention. Here, there are shown measurement results of vibration of the slider 132 (see FIG. 2) measured by a laser vibrometer in the unload state of the magnetic disk apparatus 10A (part (A) of FIG. 8) having the ramp 20A of structure shown in FIG. 4 and the magnetic disk apparatus 10B (part (B) of FIG. 8) having the ramp 20B of a structure shown in FIG. 7.
As apparent from comparison between parts (A) and (B) of FIG. 8, the airflow control plate 22 largely suppresses the vibration of the head.
FIG. 9 is a schematic diagram showing a state of a magnetic disk apparatus of a second embodiment of the present invention from which an upper cover is detached.
Elements having the same functions as those of the magnetic disk apparatuses 10A and 10B shown in FIGS. 1 and 5 are designated with the same symbols as those shown in FIG. 1 even through shapes thereof are different. Only essential different points will be explained.
In a magnetic disk apparatus 10C shown in FIG. 9, four magnetic disks 12 having the same shapes are coaxially superposed on one another at predetermined distances from one another. The magnetic disks 12 are rotated simultaneously in the direction of arrow A. Correspondingly, the same number of arms 15 as that of the magnetic heads which access first surfaces and second surfaces of the four magnetic disks 12 are formed, and the arms 15 are turned simultaneously.
A magnetic disk apparatus 10 includes a ramp 20C for holding a tip end of each arm 15 at the time of unload, a slit shroud 30 for maintaining the running stability of the arm 15 at the time of loading and unloading, and a support member 40 to which both the ramp 20C and the slit shroud 30 are fixed by means of screw and which supports both the ramp 20C and the slit shroud 30.
FIG. 10 is a partial enlarged perspective view of the ramp 20C and the slit shroud 30 of the magnetic disk apparatus 10C shown in FIG. 9. FIG. 11 is a sectional view of the ramp 20C and the slit shroud 30 shown in FIG. 10 taken along the longitudinal direction of the arm 15. FIG. 12 is a sectional perspective view of the cross section shown in FIG. 11 as viewed from a diagonal direction.
The ramp 20C and the slit shroud 30 are formed as independent parts, and they are fixed in parallel to the common support member 40 provided on a base constituting a case of the magnetic disk apparatus 10C by means of screws 51 and 52. With this, positioning of the ramp 20C and the slit shroud 30 is carried out precisely.
The arm 15 (see FIG. 9) comprises a carriage 151 of the arm 15 on the side of the rotation shaft 14, and a suspension 152 whose rear end is attached to a tip end of the carriage 151 and which further extends from the tip end of the carriage 151. As shown in FIGS. 11 and 12, the magnetic head 13 is provided on a surface of the suspension 152 that is opposed to the magnetic disk 12.
Corresponding to the number (four) of the magnetic disks 12, the slit shroud 30 is formed with four airflow control plates 301 in a form of comb.
As shown in FIG. 10, side surfaces of the four airflow control plates 301 respectively approach side surfaces of the magnetic disks 12 and are opposed thereto, and the airflow control plates 301 spread to positions where they are superposed on the suspension 152 constituting the arms 15 held by the ramp 20C.
That is, the airflow control plates 301 spread in at least the moving direction of the suspension 152 from a portion of the outer peripheral side surface of the disk 12 to a position where the airflow control plates 301 face the suspension 152 held in the ramp completion position. Each airflow control plate 301 of the slit shroud 30 extends such as to cover the longitudinal direction from a portion in the vicinity of a tip end of the suspension 152 to a portion in the vicinity of a mounting end of the carriage 151.
Therefore, by forming the airflow control plate 301 of the slit shroud 30 into the shape that is as close as possible to the shape formed along the locus of the suspension 152 which moves on the ramp 20C from a ramp opening-start position to a ramp completion position, it is possible to reliably prevent the influence of airflow. In this embodiment, the suspension 152 is made of material having elasticity, and the carriage 151 is made of material having rigidity. Therefore, in this case, it is preferable that at least the suspension 152 has such a shape that it is not influenced by airflow.
To prevent the influence of airflow on the carriage 151, the slit shroud 30 may have such a shape that it extends close to the rotation shaft 14.
Since the disk apparatus has the airflow control plate 301, it is possible to shut off the vertical airflow at and near an outer peripheral end of each magnetic disk surface at the time of loading and unloading of the magnetic head of the tip end of the suspension 152. Therefore, the environment of the magnetic head 13 is stabilized, the load/unload operation is carried out stably under the stable environment, and the possibility of contact of the magnetic head 13 to the magnetic disk is largely reduced.
The slit shroud 30 is disposed very close to the side surface of the ramp 20C. The airflow control plate 301 is provided with a relief groove 302 (see FIG. 10) such as to avoid the interference with the ramp 20C. Therefore, the airflow control plate 301 of the slit shroud 30 can be close to the side surface of the ramp 20C as close as possible, and influence of airflow in the vicinity of the magnetic head 30 of the tip end of the suspension 152 is suppressed.
The slit shroud 30 can rotate with respect to a support body 40 around the screw 52 in a state where the screw 52 is loosened. Therefore, the positioning operations of the ramp 20C and the arm 50 are facilitated when the disk apparatus is assembled.
The suspension 152 loads and unloads along the upper surfaces of the four airflow control plates 301, in the slit sandwiched between the airflow control plates 301 and along the lower surfaces of the airflow control plates 301.
Each of the airflow control plates 301 has the same thickness as that of one magnetic disk 12, and has the same surface as that of the magnetic disk 12. Therefore, environment such as strength of wind and a direction of wind at the time of loading and unloading of the arm 15 (suspension 152) is substantially similar to the environment on the magnetic disk 12, and the load/unload operation is carried out stably while avoiding generation of unintentional wind.
Although the present invention has been explained based on the magnetic disk apparatus, the invention is not limited to the magnetic disk apparatus, and the invention can be applied also to a disk apparatus comprising a disk and a head with the same structure.
Patent Application
20080037176
