# US 8,149,544 B2 · Hard disk drive with recessed actuator joint > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,149,544 B2 - Document ID: US8149544B2 - Status: Granted - Kind: B2 - Application number: 12/098,909 - Filed: 2008-04-07 - Published: 2009-10-08 - Granted: 2012-04-03 - Earliest claimed: 2008-04-07 - Assignees: Hitachi Global Storage Technologies Netherlands B.V. - Inventors: Takaaki Deguchi; Jr-Yi Shen; Kunihiro Shida; Hitoshi Shindo - Web page: https://patentgrep.com/patent/US8149544B2 ## CPC - G11B 5/5569: {details of specially adapted mobile parts, e.g. electromechanical control devices (motors in general H02K)} - 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 Components and assemblies for a hard disk drive (HDD) with a recessed actuator joint are described. A rotary actuator hub assembly comprises a shaft having a flange, and a pivot seat on which the flange is seated when the shaft is fastened to an HDD chassis. According to an embodiment, the pivot seat has at least one “contact-reducing feature” recessed from the surface of the pivot seat at which the seat contacts the flange. A purpose of the contact-reducing feature(s) of the pivot seat is to weaken the joint between the actuator hub assembly and the chassis, thereby mechanically loosening the rotary actuator assembly from the chassis. Consequently, movements to and vibrations from the chassis are less likely to be transmitted to the rotary actuator assembly and, ultimately, to the HDD read/write head(s). ## Claims ### Claim 1 A hard disk drive rotary actuator hub assembly, comprising: a shaft, comprising a flange; a pivot seat on which said flange is seated, said pivot seat comprising at least one contact-reducing feature recessed from a surface of said pivot seat at which said flange and said pivot seat contact when coupled, said at least one contact-reducing feature comprises an annular groove; and a fastener coupling said shaft to a hard disk drive chassis through said pivot seat. ### Claim 2 (depends on 1) The hard disk drive rotary actuator hub assembly recited in claim 1, wherein said at least one contact-reducing feature comprises a plurality of recesses. ### Claim 3 (depends on 2) The hard disk drive rotary actuator hub assembly recited in claim 2, wherein said plurality of recesses comprises a plurality of circular recesses. ### Claim 4 (depends on 3) The hard disk drive rotary actuator hub assembly recited in claim 3, wherein said circular recesses are a substantially equal angular distance apart. ### Claim 5 (depends on 3) The hard disk drive rotary actuator hub assembly recited in claim 3, wherein said plurality of recesses comprises three circular recesses at a substantially equal angular distance apart. ### Claim 6 (depends on 2) The hard disk drive rotary actuator hub assembly recited in claim 2, wherein said plurality of recesses comprises a plurality of elliptical recesses. ### Claim 7 (depends on 1) The hard disk drive rotary actuator hub assembly recited in claim 1, wherein said at least one contact-reducing feature comprises (a) a circular recess having an outer diameter substantially equal to an outer diameter of said flange and (b) a plurality of protrusions protruding from said circular recess in a direction toward said flange. ### Claim 8 (depends on 7) The hard disk drive rotary actuator hub assembly recited in claim 7, wherein said plurality of protrusions comprises a plurality of at least a portion of circular protrusions. ### Claim 9 (depends on 7) The hard disk drive rotary actuator hub assembly recited in claim 7, wherein said plurality of protrusions comprises three circular protrusions at a substantially equal angular distance apart. ### Claim 10 (depends on 7) The hard disk drive rotary actuator hub assembly recited in claim 7, wherein said plurality of protrusions comprises a plurality of at least a portion of elliptical protrusions. ### Claim 11 A hard disk drive device comprising: a base; a magnetic storage medium assembly coupled with said base, said magnetic storage medium rotatable relative to said base; a rotary actuator hub assembly, comprising, a shaft, comprising a flange; a sleeve encircling a portion of said shaft and rotatable relative to said shaft; one or actuator arms coupled with said sleeve and rotatable relative to said shaft, said one or more actuator arms housing one or more corresponding read/write heads for reading data from and writing data to said magnetic storage medium; a pivot seat on which said flange is seated, said pivot seat comprising a contact-reducing feature recessed from a surface of said pivot seat at which said flange and said pivot seat contact when coupled, said contact-reducing feature comprises a plurality of circular recesses; and a fastener coupling said shaft to said base through said pivot seat. ### Claim 12 (depends on 11) The hard disk drive device recited in claim 11, wherein said contact-reducing feature comprises an annular groove. ### Claim 13 (depends on 11) The hard disk drive device recited in claim 11, wherein said circular recesses are a substantially equal angular distance apart. ### Claim 14 (depends on 11) The hard disk drive device recited in claim 11, wherein said plurality of recesses comprises three circular recesses at a substantially equal angular distance apart. ### Claim 15 (depends on 1) The hard disk drive device recited in claim 1, wherein said contact-reducing feature comprises (a) a circular recess having an outer diameter substantially equal to an outer diameter of said flange and (b) a plurality of protrusions protruding from said circular recess in a direction toward said flange. ### Claim 16 (depends on 15) The hard disk drive device recited in claim 15, wherein said plurality of protrusions comprises a plurality of at least a portion of circular protrusions. ### Claim 17 (depends on 15) The hard disk drive device recited in claim 15, wherein said plurality of protrusions comprises three circular protrusions at a substantially equal angular distance apart. ### Claim 18 (depends on 15) The hard disk drive device recited in claim 15, wherein said plurality of protrusions comprises a plurality of at least a portion of elliptical protrusions.