Resonant frequency separation for an actuator assembly of a disc drive
View Patent ↗An actuator assembly is provided that includes a body portion, a first actuator arm assembly, a second actuator arm assembly, a first flexure assembly, and a second flexure assembly. Each of the first and second actuator arm assemblies projects from the body portion and has a distal end with different respective first and second mechanical configurations, sometimes referred to herein as “mounting configurations.” Each of the flexure assemblies is respectively mounted to the distal ends of the first and second actuator arm assemblies via the respective mounting configuration. The first and second mechanical configurations (mounting configurations) are selected to provide the first and second flexure assemblies with different mechanical resonance characteristics. In a preferred embodiment, the second actuator arm assembly includes an actuator arm and a spacer disposed between the actuator arm and the second flexure assembly. The spacer has a stiffness different from the stiffness of the actuator arm.
1. An actuator assembly, comprising:
a bearing having a rotatable hub;
a body attached to the hub and fixed in rotation with the hub;
first and second actuator arms longitudinally cantilevered from the body and having respective first and second mounting configurations at distal ends of the actuator arms, the actuator arms identically configured except for the first mounting configuration being differently mechanically configured than the second mounting configuration; and
first and second identically configured flexure assemblies respectively mounted to the actuator arms via the first and second mounting configurations, the first and second mounting configurations producing different operable resonance responses in the respective first and second flexure assemblies.
2. The actuator assembly of claim 1 wherein at least one of the first and second mounting configurations comprises a spacer disposed between the actuator arm and the respective flexure assembly.
3. The actuator assembly of claim 2 wherein the spacer comprises a characteristic material stiffness, and the actuator arms comprise a different characteristic material stillness.
4. The actuator assembly of claim 2 wherein a combined thickness of one of the actuator arms and flexure assembly with the spacer is identical to a combined thickness of another one of the actuator arms and flexure assembly without the spacer.
5. The actuator assembly of claim 2 wherein one of the first or second flexure assemblies is attached to one side of one of the actuator arms and a third flexure assembly is attached to an opposing side of the same actuator arm.
6. The actuator assembly of claim 1 wherein the first and second mounting configurations comprise members having surfaces to which the respective flexure assembly is attached, the surfaces being of different longitudinal lengths depending from each of the identically configured portions of the actuator arms.
7. The actuator assembly of claim 1 wherein the first and second mounting configurations comprise members to which the respective flexure assembly is attached, the members having different lateral thicknesses depending from each of the identically configured portions of the actuator arms.
8. The actuator assembly of claim 1 , wherein the first and second mounting configurations comprise swage interconnections mounting the flexure assemblies to the actuator arms.
9. The actuator assembly of claim 1 , wherein the first and second mounting configurations comprise adhesive mounting the flexure assemblies to the actuator arms.
10. A method for forming an actuator, comprising:
positioning first and second identically configured flexure assemblies;
positioning a body having longitudinally cantilevered first and second identically configured actuator arms except for having different mechanically configured mounting configurations supported at distal ends thereof, each mounting configuration adapted for mounting one of the flexure assemblies;
mounting each of the flexure assemblies to one of the actuator arms via a respective one of the mounting configurations; and
affixing the body to a rotatable hub of a bearing.
11. The method of claim 10 , wherein the positioning a body step is characterized by the different mechanically configured mounting configurations including differently sized members depending respectively from the identically configured portions of the actuator arms to which the flexure assemblies are mounted.
12. The method of claim 10 , wherein the mounting step comprises interposing a spacer between one of the actuator arms and the respective flexure assembly.
13. The method of claim 11 wherein the positioning a body is characterized by the differently sized members having different longitudinal lengths.
14. An actuator assembly, comprising:
a body;
first and second actuator arms longitudinally cantilevered from the body and defining respective first and second mounting areas at distal ends thereof, the actuator arms being identically configured except for the mounting areas being differently configured by different longitudinal lengths; and
first and second identically configured flexure assemblies respectively attached to the mounting areas.
15. The actuator assembly of claim 14 wherein the mounting areas are configured differently to produce predetermined different characteristic resonance responses.
16. The actuator assembly of claim 14 wherein adhesive is used to attach the flexure assemblies to the mounting areas.