# US 7,745,968 B2 · Motor and disc drive with motor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,745,968 B2 - Document ID: US7745968B2 - Status: Granted - Kind: B2 - Application number: 11/896,944 - Filed: 2007-09-06 - Published: 2008-03-13 - Granted: 2010-06-29 - Earliest claimed: 2006-09-07 - Assignees: Alphana Technology Co., Ltd. - Inventors: Mitsuo Kodama; Takuji Yamada; Matomo Nagaoka - Web page: https://patentgrep.com/patent/US7745968B2 ## CPC - H02K 7/085: {radially supporting the rotary shaft at only one end of the rotor (H02K7/086, H02K7/09 take precedence)} - F16C 17/026: {with helical grooves in the bearing surface to generate hydrodynamic pressure, e.g. herringbone grooves} - F16C 17/10: for both radial and axial load - F16C 33/107: {Grooves for generating pressure} - G11B 19/2036: {Motors characterized by fluid-dynamic bearings} - 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 - 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 motor includes a sleeve, a sleeve holder, a rotor hub and an inner body. The sleeve has a flange portion on an outer circumference portion thereof. The sleeve holder holds the sleeve. The rotor hub has an annular wall portion. The inner body is fixed in an inside of the annular wall portion so as to surround the sleeve and the sleeve holder. The inner body has an annular protrusion portion which is sandwiched between the flange portion and one end portion of the sleeve holder on an inner circumference portion of thereof. A first thrust bearing portion in which a lubrication agent is filled is formed between the annular protrusion portion and the flange portion. A second thrust bearing portion in which the lubrication agent is filled is formed between the annular protrusion portion and the one end portion of the sleeve holder. ## Claims ### Claim 1 A motor comprising: a sleeve having a flange portion on an outer circumference portion thereof and configured to rotatably support a rotor spindle; a sleeve holder configured to hold the sleeve; a rotor hub having an annular wall portion which has the same center axis as the rotor spindle and configured to rotate together with the rotor spindle; an inner body fixed in an inside of the annular wall portion so as to surround the sleeve and the sleeve holder, wherein the inner body has an annular protrusion portion which is sandwiched between the flange portion and one end portion of the sleeve holder, on an inner circumference portion thereof; a first thrust bearing portion formed between the annular protrusion portion and the flange portion, the first thrust bearing portion having a first groove, which is formed on a surface of the annular protrusion portion and the flange portion opposed to each other in an axial direction of the motor, for increasing the pressure of lubricant agent filled in the first thrust bearing portion, and supporting thrust loads using the first groove; and a second thrust bearing portion formed between the annular protrusion portion and the one end portion of the sleeve holder, the second thrust bearing portion having a second groove, which is formed on another surface of the annular protrusion portion and the end portion of the sleeve holder opposed to each other in the axial direction of the motor, for increasing the pressure of lubricant agent filled in the second thrust bearing portion, and supporting thrust loads using the second groove. ### Claim 2 (depends on 1) The motor according to claim 1, wherein the inner body has a first end portion which abuts to an inner surface of the rotor hub and a second end portion which protrudes from the annular wall portion and is held by a whole inner circumference of the annular wall portion of the rotor hub. ### Claim 3 (depends on 2) The motor according to claim 2, wherein the inner body and the rotor hub are made of a magnetic material and a non-magnetic material, respectively, and a field magnet is fixed to an outer circumference surface of the second end portion. ### Claim 4 (depends on 1) The motor according to claim 1, wherein the rotor hub has a second annular wall portion outside the annular wall portion and a field magnet is fixed to an inner circumference surface of the second annular wall portion. ### Claim 5 (depends on 4) The motor according to claim 4, wherein the inner body and the rotor hub are made of a non-magnetic material and a magnetic material, respectively. ### Claim 6 A disc drive comprising: a housing; and a motor built into the housing, wherein the motor comprising: a sleeve having a flange portion on an outer circumference portion thereof and configured to rotatably support a rotor spindle; a sleeve holder configured to hold the sleeve; a rotor hub having an annular wall portion which has the same center axis as the rotor spindle and configured to rotate together with the rotor spindle; an inner body fixed in an inside of the annular wall portion so as to surround the sleeve and the sleeve holder, wherein the inner body has an annular protrusion portion which is sandwiched between the flange portion and one end portion of the sleeve holder, on an inner circumference portion thereof; a first thrust bearing portion formed between the annular protrusion portion and the flange portion, the first thrust bearing portion having a first groove, which is formed on a surface of the annular protrusion portion and the flange portion opposed to each other in an axial direction of the motor, for increasing the pressure of lubricant agent filled in the first thrust bearing portion, and supporting thrust loads using the first groove; and a second thrust bearing portion formed between the annular protrusion portion and the one end portion of the sleeve holder, the second thrust bearing portion having a second groove, which is formed on another surface of the annular protrusion portion and the end portion of the sleeve holder opposed to each other in the axial direction of the motor, for increasing the pressure of lubricant agent filled in the second thrust bearing portion, and supporting thrust loads using the second groove. ### Claim 7 (depends on 1) The motor according to claim 1, further comprising: a taper seal portion formed between the inner body and the sleeve holder to hold the lubricant agent.