Claims
- 1. A hydrodynamic bearing comprising a shaft with a thrust plate mounted at an end thereof, a sleeve mounted for rotation relative to the shaft, a counterplate supported from the sleeve and overlying the thrust plate, the shaft having a journal bearing defined between the shaft outer surface and an inner surface of the sleeve, a thrust bearing on a surface of the thrust plate between the thrust plate and the sleeve, each of the journal bearing and thrust bearing being established by fluid maintained and circulated in a gap between the shaft and thrust plate and the sleeve, the fluid being maintained in a gap which extends between the shaft and the sleeve and between axially upper and lower and radially outer surfaces of the thrust plate and the surrounding sleeve and counterplate and between the shaft and surrounding sleeve and a shallow angle v-shaped region defined in a low pressure region in the gap.
- 2. A hydrodynamic bearing as claimed in claim 1 wherein an axially upper surface of the thrust plate includes a thrust bearing defined thereon facing the counterplate, and wherein the shallow V-shaped region is in the region which is radially interior to the thrust bearing.
- 3. A hydrodynamic bearing as claimed in claim 2 wherein the shallow region is a substantially V-shaped groove, with the center of the V being at the center axis of the shaft.
- 4. A hydrodynamic bearing as claimed in claim 2 wherein the shaft extends through the thrust plate to face the counterplate, and wherein the shallow V-shaped countersink is defined at the end of the shaft.
- 5. A hydrodynamic bearing as claimed in claim 4 wherein the shallow V-shaped region is a countersink coaxial with the center axis of the shaft.
- 6. A fluid dynamic bearing as claimed in claim 4 wherein the countersink is at an angle of about 8-12 degrees with the surface of the thrust plate.
- 7. A hydrodynamic bearing as claimed in claim 3 including one or more fluid circulation holes extending from a point between the journal bearing and the thrust bearing on the axially lower surface of the thrust plate at a shallow angle to intersect the countersink defined on the upper surface of the thrust plate.
- 8. A hydrodynamic bearing as claimed in claim 7 wherein each of the shallow fluid circulation holes meet at about the same point at the center axis of the shaft and countersink.
- 9. A hydrodynamic bearing as claimed in claim 8 wherein the fluid circulation holes meet the axially upper surface of the thrust plate at a point which is radially interior to the thrust bearing.
- 10. A hydrodynamic bearing as claimed in claim 9 wherein the countersink is at an angle of about 8-12 degrees with the surface of the thrust plate.
- 11. A hydrodynamic bearing as claimed in claim 1 wherein the shallow angle region is defined in the gap at the radial outer diameter of the thrust plate.
- 12. A hydrodynamic bearing as claimed in claim 11 wherein the shallow angle recess occupies substantially the entire outer diameter surface of the thrust plate.
- 13. A hydrodynamic bearing as claimed in claim 1 wherein the shaft supports the shallow angle region in the surface of the shaft adjacent the journal bearing.
- 14. A hydrodynamic bearing as claimed in claim 13 wherein the shallow angle region occupies the low pressure region intermediate first and second journal bearings defined along the shaft to support the shaft for rotation and the sleeve for relative rotation.
- 15. A hydrodynamic bearing as claimed in claim 14 wherein the shaft includes a bore extending radially from the low pressure region to about the center of the shaft, and axially to an exit at the distal surface of the thrust plate intermediate the thrust bearing.
- 16. A spindle motor for use in a disc drive comprising a shaft and a sleeve mounted for relative rotation, the sleeve supporting a hub supporting one or more discs thereon for constant speed rotation as driven by said motor, and the shaft having a journal bearing defined between the shaft outer surface and an inner surface of the sleeve, a thrust bearing on a surface of the thrust plate between the thrust plate and the sleeve, each of the journal bearing and thrust bearing being established by fluid maintained and circulated in a gap between the shaft and thrust plate and the sleeve, the fluid being maintained in a gap which extends between the shaft and the sleeve and between axially upper and lower and radially outer surfaces of the thrust plate and the surrounding sleeve and counterplate and between the shaft and surrounding sleeve and a shallow angle v-shaped region defined in a low pressure region in the gap.
- 17. A spindle motor as claimed in claim 1 wherein the shallow angle region is a countersink region in an end of the shaft extending through the thrust plate.
- 18. A spindle motor as claimed in claim 1 wherein the shallow angle region is defined in a low pressure region intermediate thrust bearings on axially upper and lower surfaces of the thrust plate, and is defined on a radially outer diameter of the thrust plate.
- 19. A spindle motor as claimed in claim 1 wherein the shallow angle region is defined in a low pressure region separate from the journal bearing supporting the shaft and thrust plate for relative rotation.
- 20. A hydrodynamic bearing comprising a shaft with a thrust plate mounted at an end thereof, a sleeve mounted for rotation relative to the shaft, a counterplate supported from the sleeve and overlying the thrust plate, the shaft having a journal bearing defined between the shaft outer surface and an inner surface of the sleeve, a thrust bearing on a surface of the thrust plate between the thrust plate and the sleeve, each of the journal bearing and thrust bearing being established by fluid maintained and circulated in a gap between the shaft and thrust plate and the sleeve, the fluid being maintained in a gap which extends between the shaft and the sleeve and between axially upper and lower and radially outer surfaces of the thrust plate and the surrounding sleeve and counterplate and means for entrapping air bubbles in the fluid in said gap in a low pressure region spaced from the fluid bearings.
Parent Case Info
[0001] This application claims benefit of U.S. Provisional Application No. 60/236,008, filed Sep. 27, 2000 entitled FLUID DYNAMIC BEARING LUBRICANT AIR EXTRACTION DEVICE all of which is hereby incorporated by reference in its entirety.
PCT Information
Filing Document |
Filing Date |
Country |
Kind |
PCT/US01/20994 |
6/29/2001 |
WO |
|
Provisional Applications (1)
|
Number |
Date |
Country |
|
60236008 |
Sep 2000 |
US |