Shock resistant fluid dynamic bearing motor

Abstract

A system, method and means is provided for withstanding mechanical shock for use with fluid dynamic bearings. A sealing system is provided that withstands 1000 G shock events. In an aspect, a grooved pumping seal employed between a thrust plate and a shield, a thrust plate having spiral grooves, a fluid recirculation passageway, and a reservoir creates an asymmetric pressure gradient. In an aspect, fluid is retained and air is purged utilizing an enlarged fluid reservoir, axial channels and an angled fill hole. In an aspect, a shaft is attached to a top cover supplying radial stiffness, and an enlarged single-sided thrust plate improves dynamic parallelism.

1 - 20 . (canceled) 
     
     
         21 . An apparatus comprising:
 an inner component;   an outer component, wherein
 said inner component and said outer component define a journal bearing, 
 said inner component and said outer component are positioned for relative rotation, and 
 said inner component and said outer component define a portion of a stationary component and a rotatable component; and 
   a means for creating an asymmetric pressure gradient within a fluid recirculation passageway, for circulating a fluid, and for purging air in said fluid, wherein
 said fluid circulates about a portion of said journal bearing, a first fluid passageway, and a second fluid passageway, and 
 said means for creating said asymmetric pressure gradient, for circulating said fluid, and for purging said air comprises spiral grooves defined on at least one of a radial member and said outer component to generate pumping pressure to drive fluid recirculation and to pump said fluid from said second fluid passageway toward said inner component and into said journal bearing, wherein said inner component and said outer component are in relative rotational motion. 
   
     
     
         22 . The apparatus of  claim 21  wherein:
 said fluid recirculation passageway includes said first fluid passageway defined within said outer component, 
 said first fluid passageway is in fluid communication with said second fluid passageway, 
 said second fluid passageway is defined between said outer component and said radial member, 
 said radial member extends radially from said inner component, and 
 said first fluid passageway and said second fluid passageway are in fluid communication with said journal bearing at separate locations. 
 
     
     
         23 . The apparatus of  claim 21  further comprising:
 a shield connected to one of said stationary component and said rotatable component, defining a reservoir with said outer component; and 
 a recirculation plenum defined by a junction joining said reservoir, said first fluid passageway and said second fluid passageway. 
 
     
     
         24 . The apparatus of  claim 23  further comprising a means for sealing said reservoir comprising a capillary seal defined between said shield and said outer component. 
     
     
         25 . The apparatus of  claim 23  further comprising:
 axial channels on at least a portion of an inner surface of said shield extending from said recirculation plenum and along said reservoir, wherein said axial channels are operable to allow air flow within said fluid to move along said axial channels and be purged from said fluid. 
 
     
     
         26 . The apparatus of  claim 21  wherein said inner component comprises a shaft and said outer component comprises a sleeve. 
     
     
         27 . The apparatus of  claim 21  further comprising a groove pattern on a portion of one of said inner component and said outer component comprising one of a herringbone pattern and a sinusoidal pattern. 
     
     
         28 . A spindle motor comprising:
 a journal bearing defined by an inner component and an outer component, wherein
 said inner component and said outer component are positioned for relative rotation, and 
 said inner component and said outer component define a portion of a stationary component and a rotatable component; and 
   a means for creating an asymmetric pressure gradient within a fluid recirculation passageway, for circulating a fluid, and for purging air in said fluid, wherein
 said fluid circulates about a substantial portion of said journal bearing, a first fluid passageway, and a second fluid passageway, 
 said means comprises pumping grooves on a facing surface positioned at an outer diameter gap defined between a shield and an outer diameter of a radial member, and is operable to pump fluid from said outer diameter gap toward a recirculation plenum when said inner component and said outer component are relatively rotating, and 
 wherein said recirculation plenum is defined by a junction joining a reservoir, said first fluid passageway, and said second fluid passageway. 
   
     
     
         29 . The apparatus of  claim 28  wherein:
 said fluid recirculation passageway includes said first fluid passageway defined within said outer component, 
 said first fluid passageway is in fluid communication with said second fluid passageway, 
 said second fluid passageway is defined between said outer component and said radial member, 
 said radial member extends radially from said inner component, and 
 said first fluid passageway and said second fluid passageway are in fluid communication with said journal bearing at separate locations. 
 
     
     
         30 . The apparatus of  claim 28  wherein said shield is connected to one of said stationary component and said rotatable component. 
     
     
         31 . The apparatus of  claim 28  further comprising a grooved pumping seal formed by spiral grooves on said radial member or said shield adjacent to said outer diameter gap. 
     
     
         32 . The apparatus of  claim 28  further comprising:
 axial channels on at least a portion of an inner surface of said shield extending from said recirculation plenum and along said reservoir, wherein said axial channels are operable to allow air flow within said fluid to move along said axial channels and be purged from said fluid. 
 
     
     
         33 . The apparatus of  claim 28  wherein said inner component comprises a shaft and said outer component comprises a sleeve. 
     
     
         34 . The apparatus of  claim 28  further comprising a groove pattern on a portion of one of said inner component and said outer component comprising one of a herringbone pattern and a sinusoidal pattern. 
     
     
         35 . A motor comprising:
 an inner component;   an outer component, wherein
 said inner component and said outer component define a journal bearing, 
 said inner component and said outer component are positioned for relative rotation, and 
 said inner component and said outer component define a portion of a stationary component and a rotatable component; and 
   a means for creating an asymmetric pressure gradient within a fluid recirculation passageway, wherein
 said means for creating said asymmetric pressure gradient comprises spiral grooves defined on at least one of a radial member and said outer component operable to generate pumping pressure to drive fluid recirculation and to pump a fluid from said second fluid passageway toward said inner component and into said journal bearing, wherein said inner component and said outer component are in relative rotational motion. 
   
     
     
         36 . The apparatus of  claim 35  wherein:
 said fluid recirculation passageway includes a first fluid passageway defined within said outer component, 
 said first fluid passageway is in fluid communication with a second fluid passageway, 
 said second fluid passageway is defined between said outer component and said radial member, 
 said radial member extends radially from said inner component, and 
 said first fluid passageway and said second fluid passageway are in fluid communication with said journal bearing at separate locations. 
 
     
     
         37 . The apparatus of  claim 35  further comprising:
 a shield connected to one of said stationary component and said rotatable component, defining a reservoir with said outer component; and 
 a recirculation plenum defined by a junction joining said reservoir, a first fluid passageway and a second fluid passageway. 
 
     
     
         38 . The apparatus of  claim 37  further comprising:
 a means for sealing said reservoir comprising at least one of a capillary seal defined between said shield and said outer component, and a grooved pumping seal formed by spiral grooves on at least one of said radial member and said shield adjacent to an outer diameter gap defined between said shield and an outer diameter of said radial member, said outer diameter gap joining said junction. 
 
     
     
         39 . The apparatus of  claim 37  further comprising:
 axial channels on at least a portion of an inner surface of said shield extending from said recirculation plenum and along said reservoir, wherein said axial channels are operable to allow air flow within said fluid to move along said axial channels and be purged from said fluid. 
 
     
     
         40 . The apparatus of  claim 35  further comprising a groove pattern on a portion of one of said inner component and said outer component comprising one of a herringbone pattern and a sinusoidal pattern.