Disk clamp balancing in a disc stack assembly
View Patent ↗An apparatus and method for balancing a disc stack assembly of a disc drive where a clamp is used as a counter-balance as well as for securing a disc to the disc stack assembly. The clamp and spindle motor are configured for positive engagement and alignment with the use of a minimal number of parts. The clamp includes a cavity through which a protrusion or a shaft of the spindle motor hub may extend. The clamp may be further secured in a desired orientation by the use of a single fastener.
1. A motor comprising:
a hub and shaft assembly fixed together for rotation and defining an alignment feature in relation to an axis of rotation; and
a clamp comprising an edge defining a central aperture adapted for receivingly engaging the alignment feature to align the clamp with the axis of rotation; and
a fastener with a medial portion thereof passing through the aperture and a distal end of the fastener engaging the hub and shaft assembly to compressingly engage a proximal end of the fastener against a portion of the clamp comprising the edge, fixing the clamp in rotation with the hub and shaft assembly.
2. The motor of claim 1 wherein a longitudinal length of the edge defining the clamp aperture is greater than a longitudinal length of the alignment feature.
3. The motor of claim 1 in which the alignment feature comprises the shaft.
4. The motor of claim 1 in which the alignment feature comprises the hub.
5. The motor of claim 1 in which the aperture is configured for an interference fit with the alignment feature.
6. The motor of claim 1 in which the clamp further comprises an indentation feature such that a center of mass of the clamp does not coincide with the axis of rotation.
7. The motor of claim 6 in which the indentation feature is formed at an outer edge of the clamp.
8. The motor of claim 1 in which the clamp is resiliently deformed by engagement with the fastener.
9. The motor of claim 1 further comprising a first disc, the first disc being held against the hub by a contact portion of the clamp.
10. An apparatus comprising a motor supporting a disc, the motor comprising:
a hub and shaft assembly fixed together for rotation about an axis of rotation and defining an alignment feature in relation to the axis of rotation;
a clamp comprising an edge defining a central aperture that is matingly engageable with the alignment feature to align the clamp with the axis of rotation; and
a fastener with a medial portion thereof passing through the aperture and a distal end of the fastener engaging the hub and shaft assembly to compressingly engage a proximal end of the fastener against a portion of the clamp comprising the edge, fixing the clamp in rotation with the hub and shaft assembly.
11. The apparatus of claim 10 in which the alignment feature comprises the shaft of the hub and shaft assembly.
12. The apparatus of claim 10 in which the alignment feature comprises the hub.
13. The apparatus of claim 10 in which the aperture is configured for an interference fit with the alignment feature.
14. The apparatus of claim 10 in which the clamp further comprises an indentation feature such that a center of mass of the clamp does not coincide with the axis of rotation.
15. The apparatus of claim 14 in which the indentation feature is formed at an outer edge of the clamp.
16. The apparatus of claim 10 in which the clamp is resiliently deformed by engagement with the fastener.
17. The apparatus of claim 10 in which the disc is held against the hub by a contact portion of the clamp.
18. An apparatus comprising:
a base;
a disc stack assembly rotatably mounted to the base; and
means for balancing the disc stack assembly.
19. The apparatus of claim 18 in which the means for balancing is characterized by aligning a clamp of the disc stack assembly with an axis of rotation.
20. The apparatus of claim 19 in which the means for balancing is characterized by rotationally positioning the clamp to offset imbalance of the disc stack assembly.