Claims
- 1. A method to reduce unbalance in a disc pack, the disc pack having a spindle motor with a hub, at least one disc, at least one spacer and wherein the method comprises steps of:
(a) creating a known unbalance on the spindle motor; and (b) biasing the disc and the spacer to achieve an allowable unbalance with respect to the unbalance of the spindle motor.
- 2. The method according to claim 1 wherein the step (a) further comprises the steps of:
(c) determining the unbalance on the spindle motor; and (d) determining the direction of the unbalance of the spindle motor.
- 3. The method according to claim 1 wherein the known unbalance on the spindle motor is created by drilling at least one hole in the spindle motor.
- 4. The method according to claim 1 wherein the step (b) further comprises the steps of:
(e) determining the unbalance of the disc; (f) determining the unbalance of the spacer; and (g) optimizing the unbalance direction of the disc, spacer and the spindle motor using vector sum of each of the three components such that the resultant is within an allowable unbalance.
- 5. The method according to claim 3 wherein the spindle motor has a feature to provide the orientation identification of the unbalance in the motor.
- 6. The method according to claim 5 wherein the feature is used to locate the motor hub at a specific orientation during the biasing process.
- 7. The method according to claim 4 provides an allowable balance in the range of 30 mg.cm □ 15 mg.cm.
- 8. A disc drive having a disc pack, the disc pack comprising:
at least one disc; at least one spacer; a disc clamp; and a spindle motor with a hub, wherein the spindle motor has a known unbalance incorporated into a biasing process to minimize an allowable unbalance of the disc pack.
- 9. The disc drive according to claim 11 wherein the known unbalance is a hole in the spindle motor.
- 10. The disc drive according to claim 11 wherein the known unbalance of the spindle motor is further demarcated with a feature to provide orientation identification.
- 11. The disc drive according to claim 12 wherein the feature locates the hub in a specific orientation during the biasing process.
- 12. The disc drive according to claim 13 wherein the known unbalance of the spindle motor fall directly opposite the feature within a range of ±30° about a line through the center of the hub and the feature.
- 13. The disc drive according to claim 12 wherein the feature is an indentation.
- 14. The disc drive according to claim 12 wherein the feature is a marker.
- 15. A disc drive having a disc pack, the disc pack comprising a disc, a spacer and a spindle motor assembled by biasing the disc and spacer in directions determined by means of a vector sum equation of the unbalance of the spindle motor, spacer and disc.
RELATED APPLICATIONS
[0001] This patent application claims priority from U.S. Provisional application No. 60/184, 929, filed Feb. 25, 2000.
Provisional Applications (1)
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Number |
Date |
Country |
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60184929 |
Feb 2000 |
US |