# US 2014/0152133 A1 · Spindle motor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0152133 A1 - Document ID: US20140152133A1 - Status: Published application - Kind: A1 - Application number: 13/757,091 - Filed: 2013-02-01 - Published: 2014-06-05 - Earliest claimed: 2012-11-30 - Assignees: Samsung Electro-Mechanics Co., Ltd. - Applicants: Samsung Electro-Mechanics Co., Ltd. - Inventors: Young Sam SHIM; Hyun Gi Yang - Web page: https://patentgrep.com/patent/US20140152133A1 ## CPC - F16C 33/745: {by capillary action} - 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 5/1675: {radially supporting the rotary shaft at only one end of the rotor (H02K5/1677 takes precedence)} - 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) - H02K: DYNAMO-ELECTRIC MACHINES (dynamo-electric relays H01H53/00; conversion of DC or AC input power into surge output power {H03K3/53}) ## Abstract There is provided a spindle motor, including: a sleeve fixed to a base member; a shaft rotatably inserted into the sleeve; and a rotor hub fixed to a top end portion of the shaft to be rotated together therewith and provided with an extension wall to form a liquid-vapor interface together with an outer circumferential surface of the sleeve, wherein the extension wall is provided with a protrusion portion protruded in an inner radial direction so as to reduce leakage of a lubricating fluid. ## Claims ### Claim 1 A spindle motor, comprising: a sleeve fixed to a base member; a shaft rotatably inserted into the sleeve; and a rotor hub fixed to a top end portion of the shaft to be rotated together therewith and provided with an extension wall to form a liquid-vapor interface together with an outer circumferential surface of the sleeve, wherein the extension wall is provided with a protrusion portion protruded in an inner radial direction so as to reduce leakage of a lubricating fluid. ### Claim 2 (depends on 1) The spindle motor of claim 1, wherein an upper portion of the outer circumferential surface of the sleeve is inclined to form the liquid-vapor interface together with the extension wall. ### Claim 3 (depends on 1) The spindle motor of claim 1, wherein the liquid-vapor interface is disposed in a space formed between an inner surface of the protrusion portion and the outer circumferential surface of the sleeve when the rotor hub is stopped, a position at which the liquid-vapor interface contacts the rotor hub is disposed above the protrusion portion in the axial direction when the rotor hub is initially rotated, and the position at which the liquid-vapor interface contacts the rotor hub is moved to contact a top surface of the protrusion portion when the rotor hub is rotated. ### Claim 4 (depends on 1) The spindle motor of claim 1, wherein the protrusion portion is disposed at an end of the extension wall. ### Claim 5 (depends on 1) The spindle motor of claim 1, wherein a diameter of an inner circumferential surface of the protrusion portion is formed to be larger than that of a top surface of the sleeve. ### Claim 6 (depends on 1) The spindle motor of claim 1, wherein the base member is provided with a mounting portion for mounting the sleeve, and the mounting portion is provided with a protruding wall to form a labyrinth seal together with the extension wall. ### Claim 7 (depends on 1) The spindle motor of claim 1, wherein at least one of a top surface of the sleeve and a bottom surface of the rotor hub disposed to face the top surface of the sleeve is provided with a thrust dynamic pressure groove. ### Claim 8 A spindle motor, comprising: a base member provided with a mounting portion protruded upwardly in an axial direction; a sleeve inserted into the mounting portion; a shaft rotatably inserted into the sleeve; a rotor hub fixed to a top end portion of the shaft to be rotated together therewith and provided with an extension wall to form a liquid-vapor interface together with an outer circumferential surface of the sleeve; and a cover member provided at a bottom end portion of the sleeve to prevent leakage of a lubricating fluid, wherein an end of the extension wall is provided with a protrusion portion protruded in an inner radial direction so as to reduce the leakage of the lubricating fluid. ### Claim 9 (depends on 8) The spindle motor of claim 8, wherein an upper portion of the outer circumferential surface of the sleeve is inclined to form the liquid-vapor interface together with the extension wall. ### Claim 10 (depends on 8) The spindle motor of claim 8, wherein the liquid-vapor interface is disposed in a space formed between an inner surface of the protrusion portion and the outer circumferential surface of the sleeve when the rotor hub is stopped, a position at which the liquid-vapor interface contacts the rotor hub is disposed above the protrusion portion in the axial direction when the rotor hub is initially rotated, and the position at which the liquid-vapor interface contacts the rotor hub is moved to contact a top surface of the protrusion portion when the rotor hub is rotated.