# US 6,296,390 B1 · Single plate hydrodynamic bearing with extended single journal bearing > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 6,296,390 B1 - Document ID: US6296390B1 - Status: Granted - Kind: B1 - Application number: 09/257,469 - Filed: 1999-02-24 - Granted: 2001-10-02 - Earliest claimed: 1994-07-22 - Assignees: Seagate Technology LLC - Inventors: Etoli Wolff; Samnathan Murthy; Norbert Steven Parsoneault; Hans Leuthold - Web page: https://patentgrep.com/patent/US6296390B1 ## CPC - F16C 17/10: for both radial and axial load - F16C 17/026: {with helical grooves in the bearing surface to generate hydrodynamic pressure, e.g. herringbone grooves} - F16C 33/107: {Grooves for generating pressure} - G11B 19/2009: {Turntables, hubs and motors for disk drives; Mounting of motors in the drive (means for clamping of disk to turntable G11B17/022 and subgroups)} - F16C 2370/12: Hard disk drives or the like - F16C: SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS - G11B: INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER (recording measured values in a way that does not require playback through a transducer G01D9/00; recording or playback apparatus using mechanically marked tape, e.g. punched paper tape, or using unit records, e.g. punched or magnetically marked cards G06K; transferring data from one type of record carrier to another G06K1/18; circuits for coupling output of reproducer to radio receiver H04B1/20; gramophone pick-ups or like acoustic electromechanical transducers or circuits therefor H04R) ## Abstract A hydrodynamic bearing having a shaft relatively rotatable with rest to a surrounding sleeve and having a thrust plate of or near one end thereof. The shaft and sleeve define a journal bearing extending substantially the full length of the two relatively rotating parts. ## Claims ### Claim 1 A hydrodynamic bearing comprising a sleeve and a shaft fitted into an axial bore of said sleeve, said shaft and said sleeve rotating relative to each other, a surface of said shaft defining together with a surface of said sleeve a single journal bearing comprising a single group of continuous curved grooves formed on one of said surfaces of said shaft and said sleeve and extending continuously along said one surface and offset toward thrust plate so that said shaft is stiffly supported within said sleeve by a fluid in a gap between said shaft and said sleeve during relative rotation of said shaft and said sleeve; said shaft further supporting an annular thrust plate, said thrust plate extending into a recess formed by an axial face of said sleeve to form a first gap, and a counterplate parallel to said thrust plate and attached to said sleeve to form a second gap, an axial face of said thrust plate defining together with the adjacent thrust plate surface a first thrust bearing including said first gap and fluid therein, and the second gap between said thrust plate and said counterpart forming a second thrust bearing with fluid therein, and wherein grooves are defined connecting said second gap to said first gap so that said fluid bearing fully supports said shaft within said sleeve. ### Claim 2 (depends on 1) A hydrodynamic bearing as claimed in claim 1 wherein a diameter of said sleeve has a ratio to a length of said journal bearing of about 1:1. ### Claim 3 (depends on 1) A bearing as claimed in claim 1 wherein the gap between the shaft and the surrounding sleeve is 5 to 7 microns. ### Claim 4 A hydrodynamic bearing comprising a sleeve and a shaft fitted into an axial bore of said sleeve, said shaft and said sleeve rotating relative to each other, a surface of said shaft defining together with a surface of said sleeve a single journal bearing comprising a single group of continuous curved grooves formed on one of said surfaces of said shaft and said sleeve and extending continuously along said one surface and offset toward thrust plate so that said shaft is stiffly supported within said sleeve by a fluid in a gap between said shaft and said sleeve during relative rotation of said shaft and said sleeve; said shaft further supporting an annular thrust plate, said thrust plate extending into a recess formed by an axial face of said sleeve to form a first gap, and a counterplate parallel to said thrust plate and attached to said sleeve to form a second gap, an axial face of said thrust plate defining together with the adjacent thrust plate surface a first thrust bearing including said first gap and fluid therein, and the second gap between said thrust plate and said counterpart forming a second thrust bearing with fluid therein, and wherein a first end of said journal bearing distal from said annular thrust plate terminates in a capillary seal formed between said bushing integral with said sleeve and said shaft of said motor. ### Claim 5 (depends on 4) A spindle as claimed in claim 4 wherein said surfaces of said sleeve is inclined away from said shaft to form said capillary seal. ### Claim 6 (depends on 5) A bearing as claimed in claim 5 wherein said curved grooves are generally sinusoidal. ### Claim 7 (depends on 4) A bearing as claimed in claim 4 wherein said curved grooves are generally sinusoidal. ### Claim 8 (depends on 1) A bearing as claimed in claim 1 wherein said curves grooves are generally sinusoidal. ### Claim 9 (depends on 8) A hydrodynamic bearing as claimed in claim 8, wherein a diameter of said sleeve has a ratio to a length of said journal bearing of about 1:1. ### Claim 10 A hydrodynamic bearing comprising a sleeve and a shaft fitted into an axial bore of said sleeve, said shaft and said sleeve rotating relative to each other, a surface of said shaft defining together with a surface of said sleeve a single journal bearing comprising a single group of continuous curved grooves formed on one of said surfaces of said shaft and said sleeve and extending continuously along said one surface and offset toward thrust plate so that said shaft is stiffly supported within said sleeve by a fluid in a gap between said shaft and said sleeve during relative rotation of said shaft and said sleeve; said shaft further supporting an annular thrust plate, said thrust plate extending into a recess formed by an axial face of said sleeve to form a first gap, and a counterplate parallel to said thrust plate and attached to said sleeve to form a second gap, an axial face of said thrust plate defining together with the adjacent thrust plate surface a first thrust bearing including said first gap and fluid therein, and the second gap between said thrust plate and said counterpart forming a second thrust bearing with fluid therein, and wherein a diameter of said sleeve has a ratio to a length of said journal bearing of about 1:1. ### Claim 11 (depends on 10) A bearing as claimed in claim 10 wherein said curved grooves are generally sinusoidal.