# US 9,001,459 B2 · Motor with stator teeth having an increased width and slanted portion > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,001,459 B2 - Document ID: US9001459B2 - Status: Granted - Kind: B2 - Application number: 13/586,100 - Filed: 2012-08-15 - Published: 2013-02-28 - Granted: 2015-04-07 - Earliest claimed: 2011-08-31 - Assignees: Nidec Corporation - Applicants: Hiroyuki Abe; Takehito Tamaoka; Kazuhiro Sato - Inventors: Hiroyuki Abe; Takehito Tamaoka; Kazuhiro Sato - Web page: https://patentgrep.com/patent/US9001459B2 ## CPC - 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)} - H02K 1/146: {consisting of a generally annular yoke with salient poles} - H02K 1/187: {to inner stators} - H02K 3/522: {for generally annular cores with salient poles} - H02K 5/225: {Terminal boxes or connection arrangements (specially adapted for submersible motors H02K5/132)} - H02K 2213/03: Machines characterised by numerical values, ranges, mathematical expressions or similar information - 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) - H02K: DYNAMO-ELECTRIC MACHINES (dynamo-electric relays H01H53/00; conversion of DC or AC input power into surge output power {H03K3/53}) ## Abstract A stator includes a stator core and a plurality of coils. The stator core includes a core-back and a plurality of teeth portions. Each of the teeth portions includes a coil winding portion, a tip end portion, and an increased width portion. The tip end portion has a circumferential width larger than a smallest width of the coil winding portion. The increased width portion has a circumferential width larger than the smallest width of the coil winding portion. The increased width portion includes a slanted portion extending radially outward and upward. An axial position of a magnetic center of the rotor magnet positioned radially outward of the stator overlaps with an axially extending range of the tip end portion. A thickness of the slanted portion in a direction perpendicular to an upper surface of the slanted portion is smaller than an axial thickness of the coil winding portion. ## Claims ### Claim 1 A motor, comprising: a stationary unit; a rotary unit including a rotor magnet; and a bearing mechanism arranged to support the rotary unit so as to rotate with respect to the stationary unit about a center axis extending in an up-down direction; wherein the stationary unit includes a stator positioned radially inward of the rotor magnet, a base portion positioned below the stator, and a stator fixing portion provided in a substantially cylindrical shape to extend upward from a central portion of the base portion, the stator being fixed to an outer circumferential surface of the stator fixing portion; the stator includes a stator core and a plurality of coils; the stator core includes an annular core-back and a plurality of teeth portions extending radially outward from the core-back; each of the teeth portions includes a coil winding portion wound with each of the coils, a tip end portion positioned radially outward of the coil winding portion, the tip end portion having a circumferential width larger than a smallest width of the coil winding portion, and an increased width portion positioned between the coil winding portion and the core-back, the increased width portion continuously extending from the coil winding portion and the core-back, the increased width portion having a circumferential width larger than the smallest width of the coil winding portion; the increased width portion includes a slanted portion extending radially outward and upward; an axial position of a magnetic center of the rotor magnet overlaps with an axial existence range of the tip end portion; and a thickness of the slanted portion in a direction perpendicular or substantially perpendicular to an upper surface of the slanted portion is smaller than an axial thickness of the coil winding portion. ### Claim 2 (depends on 1) The motor of claim 1, wherein a slot gap defined between the tip end portions of the teeth portions adjoining to each other radially overlaps with a slit defined between the increased width portions of the teeth portions adjoining to each other. ### Claim 3 (depends on 2) The motor of claim 2, wherein the slit has a circumferential maximum width equal to or smaller than a circumferential width of the slot gap. ### Claim 4 (depends on 1) The motor of claim 1, wherein the stator core includes a plurality of core members defined by axially-stacked steel plates, the coil winding portion including a caulking portion arranged to fix the core members together by caulking. ### Claim 5 (depends on 4) The motor of claim 4, wherein the core-back includes another caulking portion arranged to fix the core members together by caulking. ### Claim 6 (depends on 1) The motor of claim 1, wherein, when seen in a plan view, the increased width portion includes circumferentially opposite end sections positioned on straight lines interconnecting the center axis and the circumferentially opposite ends of the tip end portion or positioned circumferentially outward of the straight lines. ### Claim 7 (depends on 1) The motor of claim 1, wherein an inner edge section of the slanted portion is positioned radially outward of an inner edge section of the increased width portion. ### Claim 8 (depends on 7) The motor of claim 7, wherein the base portion further includes a plurality of protrusions protruding upward to position the stator core, each of the protrusions being arranged between the increased width portions of the teeth portions adjoining to each other and positioned radially inward of the inner edge section of the slanted portion. ### Claim 9 (depends on 1) The motor of claim 1, wherein an outer edge section of the slanted portion and an outer edge section of the increased width portion are defined by arc shapes about the center axis. ### Claim 10 (depends on 1) The motor of claim 1, wherein, when seen in a plan view, an outer edge section of the slanted portion and an outer edge section of the increased width portion are arranged in a rectilinear shape to extend perpendicularly or substantially perpendicularly to a straight line interconnecting the center axis and the center of the tip end portion. ### Claim 11 (depends on 10) The motor of claim 10, wherein, when seen in a plan view, the increased width portion includes circumferentially opposite end sections parallel or substantially parallel to a straight line interconnecting the center axis and the center of the tip end portion. ### Claim 12 (depends on 1) A disk drive apparatus, comprising: the motor of claim 1 arranged to rotate a disk; an access unit arranged to perform at least one of an information reading task and an information recording task with respect to the disk; and a housing arranged to accommodate the disk, the motor and the access unit.