Eliminating lead screw hysteresis for vertically translating load/unload ramp mechanism for data storage device
An approach to a reduced-head hard disk drive (HDD) includes a load/unload (LUL) ramp subsystem that includes a translatable ramp assembly that includes a biasing member and a magnet coupled thereto, which is magnetically engaged with a guide post to provide a bias force at an interface of a lead screw and the ramp assembly. The bias force acts upon the interface by reducing a gap between outer threads of the lead screw and inner threads of a mating threaded interface structure of the ramp assembly that would otherwise cause lead screw hysteresis without the bias force.
1. A vertically-translatable load/unload (LUL) ramp system for a reduced-head hard disk drive (HDD), the system comprising:
a motor configured to drive rotation of a lead screw to drive translation of a ramp assembly along an axis of the lead screw;
a plurality of guide posts positioned parallel with the lead screw and along which the ramp assembly translates;
the ramp assembly comprising:
a LUL ramp member movably engaged with a first guide post of the plurality of guide posts and engaged with the lead screw via a mating threaded interface structure;
a biasing member extending from the threaded interface structure of the LUL ramp member; and
a magnet coupled with the biasing member and magnetically engaged with a second guide post of the plurality of guide posts to provide a bias force at an interface of the lead screw and the threaded interface structure.
2. The ramp system of claim 1 , wherein the bias force acts upon the interface by reducing a gap between outer threads of the lead screw and inner threads of the mating threaded interface structure of the ramp assembly that would otherwise be present without the bias force.
3. The ramp system of claim 1 , wherein the second guide post is composed of a magnetic material.
4. The ramp system of claim 1 , wherein the plurality of guide posts interconnect an upper bracket and a lower bracket.
5. The ramp system of claim 1 , wherein a non-threaded interface structure of the LUL ramp member is positioned around the first guide post to movably engage with the first guide post.
6. The ramp system of claim 1 , wherein:
the biasing member extends from the threaded interface structure of the LUL ramp member at a proximal end of the biasing member; and
the magnet is coupled with the biasing member at a distal end of the biasing member.
7. A hard disk drive comprising the ramp system of claim 1 .
8. A reduced-head hard disk drive (HDD) comprising:
a plurality of n recording disk media rotatably mounted on a spindle;
a plurality of less than 2n head sliders each comprising a read-write transducer configured to read from and to write to at least two disk media of the plurality of disk media;
an actuator assembly configured to move the plurality of head sliders to access portions of the at least two disk media; and
a load/unload ramp system comprising:
a motor configured to drive rotation of a lead screw to drive translation of a ramp assembly along an axis of the lead screw;
a plurality of guide posts positioned parallel with the lead screw and along which the ramp assembly translates;
the ramp assembly comprising:
a LUL ramp unit movably engaged with a first guide post of the plurality of guide posts and engaged with the lead screw via a mating threaded interface structure,
a biasing unit extending from the threaded interface structure of the LUL ramp unit, and
a magnet coupled with the biasing unit and magnetically engaged with a second guide post of the plurality of guide posts to provide a bias force at an interface of the lead screw and the threaded interface structure; and
wherein the bias force acts upon the interface by reducing any gap between outer threads of the lead screw and inner threads of the mating threaded interface structure of the ramp assembly that would otherwise be present without the bias force.
9. The HDD of claim 8 , wherein the second guide post of the ramp assembly is composed of a magnetic material.
10. The HDD of claim 8 , wherein the plurality of guide posts of the ramp assembly interconnect an upper bracket and a lower bracket.
11. The HDD of claim 8 , wherein a non-threaded interface structure of the LUL ramp unit is positioned around the first guide post to movably engage with the first guide post.
12. The HDD of claim 8 , wherein:
the biasing unit of the ramp assembly extends from the threaded interface structure of the LUL ramp unit at a proximal end of the biasing unit; and
the magnet of the ramp assembly is coupled with the biasing unit at a distal end of the biasing unit.
13. A reduced-head hard disk drive (HDD), comprising:
recording means for storing digital information;
reading/writing means for reading from and writing to the recording means;
loading/unloading means for loading the reading/writing means to access the recording means and unloading the reading/writing means from access to the recording means; and
translating means for translating the loading/unloading means from one recording means to another recording means;
wherein the loading/unloading means comprises means for reducing hysteresis associated with the translating means.