Balance clip holder feature on a spindle motor with nickel-teflon coating on balance clips for reducing friction during clip adjustment in balance process
View Patent ↗A spindle motor is equipped with pre-installed adjustable balance clips on a stainless steel motor hub to facilitate better balance correction. A balance clip holder feature is formed in the hub and has grooves to hold the balance clips. The balance clip holder can be an integrally formed part of the hub, or it can be a separate piece that is assembled to the hub before the complete motor is assembled. In addition, the balance clips are provided with an improved coating to reduce friction during adjustment of the clips in the balance process. Each clip has a coating of nickel-Teflon to achieve a better coating quality and cleanliness over prior art designs. The nickel-Teflon combination yields unexpected results, such as a significantly smoother surface with more uniform coating thickness, and significantly less particle sloughing to reduce contamination.
1. A spindle motor, comprising:
a base;
a shaft mounted to the base and having an axis;
a motor hub mounted to the shaft via bearings for rotation relative to the shaft, the motor hub having a single balance clip holder formed therein at only one axial end of the motor hub, the balance clip holder having at least two holder features that are substantially radially aligned with each other relative to the axis of the shaft; and
a balance clip located in the balance clip holder for adjustably balancing the motor hub for smooth rotation about the shaft during a disk pack balance process.
2. The spindle motor of claim 1 , wherein the holder features comprise grooves, and the balance clip comprises a plurality of balance clips, each of which is axially spaced apart from the others and installed in one of the grooves.
3. The spindle motor of claim 1 , wherein the balance clip holder is integrally formed with the motor hub from a single piece of stainless steel.
4. The spindle motor of claim 1 , wherein the balance clip holder is formed as a separate piece from the motor hub and is assembled to the motor hub.
5. A spindle motor, comprising:
a base;
a shaft mounted to the base and having an axis;
a motor hub formed from stainless steel and mounted to the shaft via bearings for rotation relative to the shaft, the motor hub having a single balance clip holder formed therein at one axial end of the motor hub, the balance clip holder having at least two holder features that are substantially radially aligned with each other relative to the axis of the shaft and axially spaced apart from each other;
a balance clip located in the balance clip holder for adjustably balancing the motor hub for smooth rotation about the shaft during a disk pack balance process, the balance clip being coated with a layer of nickel-filled Teflon to reduce friction during adjustment of the balance clip in the disk pack balance process.
6. A hard disk drive, comprising:
an enclosure;
a spindle motor having a shaft with an axis mounted to the enclosure, a motor hub mounted to the shaft via bearings for rotation relative to the shaft, the motor hub having a single balance clip holder with recesses formed therein at only one axial end of the motor hub, the recesses being substantially radially aligned with each other relative to the axis of the shaft and axially spaced apart from each other;
a balance clip located in and slidably mounted to the balance clip holder for adjustably balancing the motor hub for smooth rotation about the shaft during a disk pack balance process;
at least one media storage disk mounted to the motor hub for rotation therewith; and
an actuator mounted to the enclosure, the actuator having a head gimbal assembly extending therefrom for movement relative to said at least one media storage disk, and the head gimbal assembly having a read/write head for reading data from and writing data to said at least one media storage disk.
7. The hard disk drive of claim 6 , wherein the balance clip holder has a plurality of annular recesses formed therein that circumscribe the motor hub, and the balance clip comprises a plurality of annular balance clips, each of which is located in and slidably mounted to one of said plurality of recesses.
8. The hard disk drive of claim 6 , wherein the balance clip holder is integrally formed with the motor hub from a single piece of stainless steel.
9. The hard disk drive of claim 6 , wherein the balance clip holder is formed as a separate piece from the motor hub and is assembled to an outer radial circumference of the motor hub.
10. A hard disk drive, comprising:
an enclosure;
a spindle motor having a shaft with an axis mounted to the enclosure, a motor hub formed from stainless steel and mounted to the shaft via bearings for rotation relative to the shaft, the motor hub having a balance clip holder with recesses formed therein, the recesses being substantially radially aligned with each other relative to the axis of the shaft; a balance clip located in and slidably mounted to the balance clip holder for adjustably balancing the motor hub for smooth rotation about the shaft during a disk pack balance process, the balance clip being coated with a layer of nickel-filled Teflon to reduce friction during adjustment of the balance clip in a disk pack balance process;
at least one media storage disk mounted to the motor hub for rotation therewith; and
an actuator mounted to the enclosure, the actuator having a head gimbal assembly extending therefrom for movement relative to said at least one media storage disk, and the head gimbal assembly having a read/write head for reading data from and writing data to said at least one media storage disk.
11. A hard disk drive, comprising:
an enclosure;
a spindle motor having a shaft mounted to the enclosure, a motor hub formed from stainless steel and mounted to the shaft via bearings for rotation relative to the shaft, and the motor hub having an outer radial circumference;
a balance clip holder on the outer radial circumference of the motor hub, the balance clip holder having a pair of annular recesses formed on an inner surface thereof that circumscribe the motor hub;
a pair of annular balance clips, each of which is located in and slidably mounted to one of the annular recesses in the balance clip holder for adjustably balancing the motor hub for smooth rotation about the shaft during a disk pack balance correction process, each of the annular balance clips having a coating of nickel-filled Teflon to reduce friction during adjustment of the annular balance clips in the disk pack balance correction process;
a plurality of media storage disks mounted to the motor hub for rotation therewith; and
an actuator mounted to the enclosure, the actuator having a plurality of head gimbal assemblies extending therefrom for movement relative to the media storage disks, each of the head gimbal assemblies having a read/write head for reading data from and writing data to the media storage disks.
12. The hard disk drive of claim 11 , wherein the balance clip holder is integrally formed with the motor hub from a single piece of stainless steel.
13. The hard disk drive of claim 11 , wherein the balance clip holder is formed as a separate piece from the motor hub and is assembled to the outer radial circumference of the motor hub.
14. The hard disk drive of claim 11 , wherein the pair of annular recesses are substantially radially aligned with each other relative to an axis of the shaft.