EP0410293A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Spindle motor
Assignee: Ebara Corp
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Filing: 1990-07-18
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Granted: —
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Expires: 2010-07-18
Abstract
Abstract A spindle motor which is designed to rotate with minimal vibrations and hence is suitable of a hard disk driver. The spindle motor employs hydrodynamic bearings as radial and thrust bearings. A support shaft is formed in a cylindrical configuration with a center hole, and a rotor has a columnar portion which is inserted into the center hole in the support shaft. A thrust bearing collar is attached to the lower end of the rotor, and a thrust bearing member is secured to a base in opposing relation to the thrust bearing collar. A group of stator coils and a radial bearing member are disposed on either the inner peripheral surface of the center hole in the support shaft or the outer peripheral surface of the support shaft, and a group of rotor magnets and a radial bearing sleeve are disposed on either the outer peripheral surface of the columnar portion or the inner peripheral surface of the rotor in opposing relation to the stator coil group and the radial bearing member.
Inventors
- 👤 Daisuke Konno
- 👤 Sachihiko Miwa
- 👤 Shunichi Aiyoshizawa
- 👤 Kazuyuki Kashihara
- 👤 Yoshio Sato
- 👤 Kazuto Hirokawa
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-02 08:59
CPC Classifications
F; F16; F16C; F16C33/00; F16C33/02; F16C33/04; F16C33/06; F16C33/10; F16C33/1025; F16C33/106; F16C33/107; F16C17/00; F16C17/10; F16C17/102; F16C17/107; F16C25/00; F16C25/02; F16C25/04; F16C25/045; F16C39/00; F16C39/06; F16C39/063; G; G11; G11B; G11B19/00; G11B19/20; G11B19/2009; H; H02; H02K; H02K5/00; H02K5/04; H02K5/16; H02K5/167; H02K5/1677; F16C2370/00; F16C2370/12
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
211 words
A spindle motor comprising: a cylindrical support shaft which is disposed in the center of a base; a cap-shaped rotor having in the center a columnar member which is inserted into a center hole in said cylindrical support shaft; either a group of rotor magnets or a group of rotor cores which are provided on the outer peripheral surface of said columnar member of said rotor; a group of stator coils which are provided on the inner peripheral surface of said center hole in said cylindrical support shaft in opposing relation to said group of rotor magnets or rotor cores; a radial hydrodynamic bearing for supporting said rotor, which comprises a radial bearing sleeve that is concentrically and integrally provided on the inner peripheral surface of said rotor and a radial bearing member that is concentrically and integrally provided on the outer peripheral surface of said cylindrical support shaft in opposing relation to said radial bearing sleeve; and a thrust hydrodynamic bearing for supporting a cap-shaped collar portion of said rotor on said base, which comprises a thrust bearing collar that is provided on the lower end of said cap-shaped collar portion and a thrust bearing member that is provided on said base in opposing relation to said thrust bearing collar.
Claim 2
Dependent Claim
211 words
A spindle motor comprising: a cylindrical support shaft which is disposed in the center of a base; a cap-shaped rotor having in the center a columnar member which is inserted into a center hole in said cylindrical support shaft; either a group of rotor magnets or a group of rotor cores which are provided on the outer peripheral surface of said columnar member of said rotor; a group of stator coils which are provided on the inner peripheral surface of said center hole in said cylindrical support shaft in opposing relation to said group of rotor magnets or rotor cores; a radial hydrodynamic bearing for supporting said rotor, which comprises a radial bearing sleeve that is concentrically and integrally provided on the inner peripheral surface of said rotor and a radial bearing member that is concentrically and integrally provided on the outer peripheral surface of said cylindrical support shaft in opposing relation to said radial bearing sleeve; and a thrust hydrodynamic bearing for supporting a cap-shaped collar portion of said rotor on said base, which comprises a thrust bearing collar that is provided on the lower end of said cap-shaped collar portion and a thrust bearing member that is provided on said base in opposing relation to said thrust bearing collar.
Claim 3
Dependent Claim
208 words
A spindle motor comprising: a cylindrical support shaft which is disposed in the center of a base; a cap-shaped rotor having in the center a columnar member which is inserted into a center hole in said cylindrical support shaft; either a group of rotor magnets or a group of rotor cores which are provided on the inner peripheral surface of said rotor; a group of stator coils which are provided on the outer peripheral surface of said cylindrical support shaft in opposing relation to said group of rotor magnets or rotor cores; a radial hydrodynamic bearing for supporting said rotor, which comprises a radial bearing sleeve that is concentrically and integrally provided on the outer peripheral surface of said columnar member and a radial bearing member that is concentrically and integrally provided on the inner peripheral surface of said center hole in said cylindrical support shaft in opposing relation to said radial bearing sleeve; and a thrust hydrodynamic bearing for supporting a cap-shaped collar portion of said rotor on said base, which comprises a thrust bearing collar that is provided on the lower end of said cap-shaped collar portion and a thrust bearing member that is provided on said base in opposing relation to said thrust bearing collar.
Claim 4
Dependent Claim
208 words
A spindle motor comprising: a cylindrical support shaft which is disposed in the center of a base; a cap-shaped rotor having in the center a columnar member which is inserted into a center hole in said cylindrical support shaft; either a group of rotor magnets or a group of rotor cores which are provided on the inner peripheral surface of said rotor; a group of stator coils which are provided on the outer peripheral surface of said cylindrical support shaft in opposing relation to said group of rotor magnets or rotor cores; a radial hydrodynamic bearing for supporting said rotor, which comprises a radial bearing sleeve that is concentrically and integrally provided on the outer peripheral surface of said columnar member and a radial bearing member that is concentrically and integrally provided on the inner peripheral surface of said center hole in said cylindrical support shaft in opposing relation to said radial bearing sleeve; and a thrust hydrodynamic bearing for supporting a cap-shaped collar portion of said rotor on said base, which comprises a thrust bearing collar that is provided on the lower end of said cap-shaped collar portion and a thrust bearing member that is provided on said base in opposing relation to said thrust bearing collar.
Claim 5
Dependent Claim
31 words
A spindle motor according to Claim 1 or 2, wherein said thrust bearing is preloaded by a magnetic force acting counter to a dynamic pressure acting in the direction of thrust.
Claim 6
Dependent Claim
65 words
A spindle motor according to Claim 3, wherein the longitudinal magnet center of said rotor magnet group is offset from the longitudinal magnet center of said stator coil group by a predetermined distance in a counter direction to the dynamic pressure generated from said thrust bearing, thereby preloading said thrust bearing in a counter direction to the dynamic pressure acting in the direction of thrust.
Claim 7
Dependent Claim
77 words
A spindle motor according to Claim 1 or 2, wherein at least either one of said radial and thrust bearings is formed from a material selected from among a ceramic material, a material comprising a base material which is coated with a thin film of a material which is different from said base material, and a material comprising a base material which is provided with a surface layer formed by changing the properties of said base material.
Claim 8
Dependent Claim
17 words
A spindle motor according to Claim 5, wherein said ceramic material is either silicon carbide or alumina.
Claim 9
Dependent Claim
33 words
A spindle motor according to Claim 1 or 2, wherein said radial bearing is disposed so as to bear said rotor over a certain range including the center of gravity of said rotor.
Claim 10
Dependent Claim
22 words
A spindle motor according to Claim 1 or 2, wherein a resilient pad is interposed between said thrust bearing and said base.
Claim 11
Dependent Claim
14 words
A spindle motor according to Claim 8, wherein said resilient pad is silicone rubber.
Claim 12
Dependent Claim
34 words
A spindle motor according to Claim 1 or 2, wherein some or all of said radial bearing sleeve, said rotor, said columnar member and said thrust bearing collar are arranged in an integral structure.
Claim 13
Dependent Claim
54 words
A spindle motor according to Claim 10, wherein either one or both of said radial bearing sleeve and said thrust bearing collar, which are formed to be integral with each other, are coated with a material which is different from a base material therefor, or have said base material subjected to a surface treatment.
Claim 14
Dependent Claim
34 words
A spindle motor according to Claim 1 or 2, wherein some or all of said radial bearing member, said support shaft, said base and said thrust bearing member are arranged in an integral structure.
Claim 15
Dependent Claim
54 words
A spindle motor according to Claim 12, wherein either one or both of said radial bearing member and said thrust bearing member, which are formed to be integral with each other, are coated with a material which is different from a base material therefor, or have said base material subjected to a surface treatment.
Claim 16
Dependent Claim
27 words
A spindle motor according to Claim 1 or 2, wherein said rotor has a support member adapted to hold hard disks on the outer peripheral surface thereof.
References Cited (Backward Citations)
FR2278128A1
Cited
EP0206516A2
Cited
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