# US 7,608,957 B2 · Spindle motor with oil impregnated bearings and a shaft with a groove > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,608,957 B2 - Document ID: US7608957B2 - Status: Granted - Kind: B2 - Application number: 11/763,954 - Filed: 2007-06-15 - Published: 2007-12-20 - Granted: 2009-10-27 - Earliest claimed: 2006-06-16 - Assignees: LG Innotek Co., Ltd. - Inventors: Gi Seok Yun - Web page: https://patentgrep.com/patent/US7608957B2 ## CPC - H02K 5/1675: {radially supporting the rotary shaft at only one end of the rotor (H02K5/1677 takes precedence)} - F16C 33/103: {retained in or near the bearing} - F16C 33/74: of sliding-contact bearings - H02K 7/04: Balancing means - F16C 2370/12: Hard disk drives or the like - H02K: DYNAMO-ELECTRIC MACHINES (dynamo-electric relays H01H53/00; conversion of DC or AC input power into surge output power {H03K3/53}) - F16C: SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS ## Abstract A spindle motor can include a base, a bearing housing supported by the base, a bearing installed in the bearing housing, where oil is impregnated in the bearing, a rotating shaft rotatably installed in the bearing and having a groove at a predetermined surface thereof facing the bearing, a stator installed around the bearing housing and having a core and a coil, and a rotor fixed to the rotating shaft and having a rotor yoke and a magnet. ## Claims ### Claim 1 A spindle motor comprising: a bearing housing; a bearing installed in the bearing housing, the bearing being formed with oil-impregnated pores; a rotating shaft rotatably installed in the oil-impregnated bearing and having a groove at a predetermined surface thereof facing the bearing; a stator installed around the bearing housing and having a core and a coil; and a rotor fixed to the rotating shaft and having a rotor yoke and a magnet, wherein oil leaving the oil-impregnated bearing is directly re-supplied to the bearing from the interfacial surface between the bearing and the rotating shaft. ### Claim 2 (depends on 1) The spindle motor as claimed in claim 1, further comprising a stopper around an outer peripheral surface of the rotating shaft above the bearing to inhibit oil from moving upward. ### Claim 3 (depends on 2) The spindle motor as claimed in claim 2, wherein the stopper is positioned lower than an upper surface of the bearing housing. ### Claim 4 (depends on 1) The spindle motor as claimed in claim 1, wherein the rotating shaft has a plurality of the grooves at predetermined surfaces thereof facing the bearing. ### Claim 5 (depends on 1) The spindle motor as claimed in claim 1, wherein the groove has a ring shape. ### Claim 6 (depends on 1) The spindle motor as claimed in claim 1, wherein the width of the groove, which is defined in a direction parallel to the rotating shaft, gradually reduces toward a radial center of the rotating shaft. ### Claim 7 (depends on 1) The spindle motor as claimed in claim 1, wherein a lower sidewall of the groove inclines upward toward a radial center of the rotating shaft. ### Claim 8 (depends on 1) The spindle motor as claimed in claim 1, wherein an upper sidewall of the groove is horizontally formed. ### Claim 9 (depends on 1) The spindle motor as claimed in claim 1, wherein an upper sidewall of the groove inclines upward toward a radial center of the rotating shaft. ### Claim 10 (depends on 1) The spindle motor as claimed in claim 1, wherein the stator is fixed to the bearing housing. ### Claim 11 (depends on 1) The spindle motor as claimed in claim 1, wherein a lateral side of the bearing housing is integrally formed with a bottom surface of the bearing housing. ### Claim 12 (depends on 1) The spindle motor as claimed in claim 1, wherein the groove is formed at a predetermined portion of the rotating shaft that makes contact with the bearing. ### Claim 13 (depends on 1) The spindle motor as claimed in claim 1, wherein a recess is formed at a predetermined surface of the bearing facing the rotating shaft, so that a gap is formed between the bearing and the rotating shaft. ### Claim 14 (depends on 1) The spindle motor as claimed in claim 1, wherein the bearing makes contact with the rotating shaft in at least two portions thereof, and the groove is formed in the rotating shaft at predetermined surfaces corresponding to the at least two portions. ### Claim 15 A spindle motor comprising: a base; a bearing housing installed in the base; a bearing installed in the bearing housing, the bearing being formed with oil-impregnated pores; a rotating shaft rotatably installed in the oil-impregnated bearing and having a groove at a predetermined surface thereof facing the bearing; a stator installed around the bearing housing and having a core and a coil; and a rotor fixed to the rotating shaft and having a rotor yoke and a magnet, wherein the rotor yoke surrounds the stator in an outer radial direction and wherein a portion of the rotor yoke is on a same horizontal plane as the groove. ### Claim 16 (depends on 15) The spindle motor as claimed in claim 15, wherein the groove is extended perpendicularly to an axial direction of the rotating shaft. ### Claim 17 (depends on 15) The spindle motor as claimed in claim 15, further comprising a stopper attached to an outer peripheral surface of the rotating shaft that protrudes upward from the bearing in order to inhibit oil from moving upward. ### Claim 18 A spindle motor comprising: a base; a bearing housing installed in the base; a bearing installed in the bearing housing; a rotating shaft rotatably installed in the bearing and having a groove at a predetermined surface thereof facing the bearing; a stopper attached to an outer peripheral surface of the rotating shaft that protrudes upward from the bearing; a stator installed around the bearing housing and having a core and a coil; and a rotor fixed to the rotating shaft and having a rotor yoke and a magnet, wherein the rotor yoke surrounds the stator in an outer radial direction and wherein the stopper is disposed between the rotor yoke and the bearing. ### Claim 19 (depends on 18) The spindle motor as claimed in claim 18, wherein the groove is provided along an outer peripheral surface of the rotating shaft in a form of a ring. ### Claim 20 (depends on 18) The spindle motor as claimed in claim 18, further comprising a turntable fixed to the rotating shaft.