Boss location to adjust head attitude
View Patent ↗Embodiments of the present invention provide a structure of a pivot receiving surface which may excellently adjust the attitude of a head supporting mechanism in a magnetic disk drive. In one embodiment, three projections are formed at a base for supporting a pivot assembly. The first projection is formed on a first line which bisects an angle defined between a second line and a third line determining a range, in which a head/slider flies above a magnetic disk. In contrast, the other two projections are formed at positions apart from the first projection at an angle of 120°, respectively. The attitude of the pivot assembly is adjusted by adjusting the heights of the projections, and thus, a head supporting mechanism is corrected in a predetermined attitude within the range in which the head/slider flies above the magnetic disk.
1. A pivot assembly having a pivot receiving surface for rotatably supporting a head supporting mechanism having a head/slider flying over a magnetic disk mounted thereon, the pivot receiving surface comprising:
a first projection, a second projection and a third projection for supporting an abutment surface of the pivot assembly with each top surface of the projections wherein,
the first projection is formed at a position through which an outside center line Or an inside center line passes, or between the outside center line and the inside center line through which a rotation center line passes when the rotation center line of the head supporting mechanism is defined as a line passing through the center of the pivot assembly and the center of an edge on a side on which a head in the head/slider is mounted, the inside center line is defined as a line of the rotation center line when the head/slider is located at the most inside position at which the head/slider flies over the magnetic disk, and the outside center line is defined as a line of the rotation center line when the head/slider is located at the most outside position at which the head/slider flies over the magnetic disk;
the second projection is formed in one region of the base bisected by the Rotation center line passing through the first projection; and
the third projection is formed in the other region of the base bisected by the rotation center line passing through the first projection.
2. A pivot assembly as claimed in claim 1 , wherein the first projection is formed at a position through which the rotation center line for bisecting an angle defined between the inside center line and the outside center line passes.
3. A pivot assembly as claimed in claim 1 , wherein the first projection is formed nearer the head/slider than the second projection and the third projection.
4. A pivot assembly as claimed in claim 1 , wherein the second projection and the third projection are formed nearer the head/slider than the first projection.
5. A pivot assembly as claimed in claim 1 , wherein the length of a line connecting the first projection to the second projection is equal to the length of a line connecting the first projection to the third projection.
6. A pivot assembly as claimed in claim 5 , wherein the lengths of lines mutually connecting the first projection, the second projection and the third projection are equal to each other.
7. A pivot assembly as claimed in claim 1 , wherein the first projection, the second projection and the third projection are formed at a boss at a base of a magnetic disk drive.
8. A pivot assembly as claimed in claim 1 , wherein the first projection, the second projection and the third projection are molded by pressing a steel plate.
9. A pivot assembly as claimed in claim 1 , wherein the most inside position, at which the head/slider flies above the magnetic disk, is a position at which the head supporting mechanism is brought into contact with an inner crush stop.
10. A pivot assembly as claimed in claim 1 , wherein the most outside position, at which the head/slider flies above the magnetic disk, is a position at which the head supporting mechanism is brought into contact with an outer crush stop.
11. A pivot assembly as claimed in claim 1 , wherein the most outside position, at which the head/slider flies above the magnetic disk, is a position at which a lift tab of the head supporting mechanism is brought into contact with a ramp.
12. A pivot assembly as claimed in claim 1 , wherein the head supporting mechanism is a head stack assembly including a load beam and a carriage assembly to be driven by a voice coil motor.
13. A magnetic disk drive comprising:
a base;
a magnetic disk rotatably attached to the base;
a head stack assembly having a head/slider mounted thereon, the head/slider having access to the magnetic disk;
a pivot assembly having an abutment surface and fixed to the base so as to rotatably support the head stack assembly; and
a first projection, a second projection and a third projection formed at the base, for supporting the abutment surface of the pivot assembly with each top surface of the projections;
the first projection being formed at a position, through which an outside center line or an inside center line passes, or between the outside center line and the inside center line through which the rotation center line passes when the rotation center line of the head supporting mechanism is defined as a line passing through the center of the pivot assembly and the center of an edge on a side on which a head in the head/slider is mounted, the inside center line is defined as a line of the rotation center line when the head/slider is located at the most inside position at which the head/slider flies over the magnetic disk, and the outside center line is defined as a line of the rotation center line when the head/slider is located at the most outside position at which the head/slider flies over the magnetic disk;
the second projection being formed in one region of the base bisected by the rotation center line passing through the first projection; and
the third projection being formed in the other region of the base bisected by The rotation center line passing through the first projection.
14. A magnetic disk drive as claimed in claim 13 , wherein the first projection is formed at a position through which the rotation center line for bisecting an angle defined between the inside center line and the outside center line passes.
15. A magnetic disk drive as claimed in claim 13 , wherein the first projection, the second projection and the third projection are formed on one and the same circle whose center coincides with that of the pivot assembly.
16. A magnetic disk drive as claimed in claim 15 , wherein the length of a line connecting the first projection to the second projection is equal to the length of a line connecting the first projection to the third projection.
17. A magnetic disk drive as claimed in claim 13 , the magnetic disk drive adopting a contact start/stop system, wherein the most outside position, at which the head/slider flies above the magnetic disk, is a position at which the head stack assembly is brought into contact with an outer crush stop.
18. A magnetic disk drive as claimed in claim 13 , the magnetic disk drive adopting a load/unload system, wherein the most outside position, at which the head/slider flies above the magnetic disk, is a position at which a lift tab of the head stack assembly is brought into contact with a ramp.
19. A magnetic disk drive as claimed in claim 13 , wherein the most inside position, at which the head/slider flies above the magnetic disk, is a position at which the head stack assembly is brought into contact with an inner crush stop.
20. A magnetic disk drive as claimed in claim 13 , wherein the base is molded by pressing a steel plate.