US5579188A — Ironless spindle motor for disc drive

Claim 1

Independent Claim 137 words

A disc drive data storage system, comprising: a housing; a central axis; a stationary member which is fixed with respect to the housing and coaxial with the central axis; a rotatable member which is rotatable about the central axis with respect to the stationary member; a hydrodynamic bearing interconnecting the rotatable member with the stationary member; at least one data storage disc attached to and coaxial with the rotatable member; at least one magnet attached to the rotatable member; and a stator winding which is fixed with respect to the housing and is coaxial with the rotatable member, wherein the stator winding has an ironless structure which is magnetically coupled to the magnet such that the stator winding and the hydrodynamic bearing cooperate to reduce excitation of pure tone vibrations in the disc drive data storage system.

Claim 2

Dependent Claim 137 words

A disc drive data storage system, comprising: a housing; a central axis; a stationary member which is fixed with respect to the housing and coaxial with the central axis; a rotatable member which is rotatable about the central axis with respect to the stationary member; a hydrodynamic bearing interconnecting the rotatable member with the stationary member; at least one data storage disc attached to and coaxial with the rotatable member; at least one magnet attached to the rotatable member; and a stator winding which is fixed with respect to the housing and is coaxial with the rotatable member, wherein the stator winding has an ironless structure which is magnetically coupled to the magnet such that the stator winding and the hydrodynamic bearing cooperate to reduce excitation of pure tone vibrations in the disc drive data storage system.

Claim 3

Dependent Claim 43 words

The disc drive data storage system of claim 1 wherein the ironless stator winding has a radial position that is external to the magnet, with respect to the central axis, and has a common axial position with the magnet along the central axis.

Claim 4

Dependent Claim 43 words

The disc drive data storage system of claim 1 wherein the ironless stator winding has a radial position that is internal to the magnet, with respect to the central axis, and has a common axial position with the magnet along the central axis.

Claim 5

Dependent Claim 41 words

The disc drive data storage system of claim 1 wherein the ironless stator winding is magnetically coupled to the magnet in a radial direction and has an axial position that is below the rotatable member, with respect to the central axis.

Claim 6

Dependent Claim 30 words

The disc drive data storage system of claim 1 wherein the ironless stator winding has an axial position that is within the rotatable member, with respect to the central axis.

Claim 7

Dependent Claim 52 words

The disc drive data storage system of claim 1 wherein the ironless stator winding comprises a plurality of phase windings, wherein each phase winding is formed of at least one coil having a coil axis that is generally normal to and intersects the central axis of the disc drive data storage system.

Claim 8

Dependent Claim 35 words

The disc drive data storage system of claim 1 wherein the ironless stator winding has a cylindrical shape which is formed of a plurality of interwoven phase windings and is coaxial with the rotatable member.

Claim 9

Dependent Claim 32 words

The disc drive data storage system of claim 1 wherein the magnet is formed in a unitary, multipolar ring of magnetized material, which is attached to and coaxial with the rotatable member.

Claim 10

Dependent Claim 31 words

The disc drive data storage system of claim 1 wherein the magnet is formed of a plurality of individual magnets which are attached to and arranged coaxial with the rotatable member.

Claim 11

Dependent Claim 103 words

The disc drive data storage system of claim 1 wherein: the rotatable member includes a hub having an outer diameter; the magnet is attached to the outer diameter of the hub; the ironless stator winding has a radial position with respect to the central axis that is external to the magnet and has an axial position along the central axis that is common with the magnet and below the hub and the hydrodynamic bearing; and the system further comprises a magnetic field focusing member which is positioned radially external and magnetically coupled to the ironless stator winding with respect to the central axis.

Claim 12

Dependent Claim 110 words

The disc drive data storage system of claim 1 wherein: the rotatable member includes a hub having an internal cavity with an inner diameter and an outer diameter; the magnet is attached to the outer diameter of the internal cavity; the ironless stator winding has a radial position with respect to the central axis that is internal to the magnet and has an axial position along the central axis that is within the internal cavity of the hub; and the system further comprises a magnetic field focusing member which is attached to the ironless stator winding and positioned internal to the ironless stator winding with respect to the central axis.

Claim 13

Dependent Claim 70 words

The disc drive data storage system of claim 1 and further comprising: a magnetic field focusing member which is formed of a magnetic material; and wherein the ironless stator winding has a radial position between the focusing member and the magnet with respect to the central axis and is magnetically coupled to the magnetic field focusing member for focusing a magnetic field between the ironless stator winding and the magnet.

Claim 14

Dependent Claim 22 words

The disc drive data storage system of claim 12 wherein the magnetic field focusing member is formed of a solid magnetic material.

Claim 15

Dependent Claim 25 words

The disc drive data storage system of claim 12 wherein the magnetic field focusing member is formed of a plurality of laminations of magnetic material.

Claim 16

Dependent Claim 21 words

The disc drive data storage system of claim 12 wherein the magnetic field focusing member is formed in a unitary ring.

Claim 17

Dependent Claim 57 words

The disc drive data storage system of claim 12 wherein: the ironless stator winding comprises a plurality of phase windings arranged about the rotatable member; and the magnetic field focusing member includes a plurality of associated individual focusing members, wherein each of the plurality of focusing members is attached to one of the plurality of phase windings.

Claim 18

Dependent Claim 96 words

The disc drive data storage system of claim 1 wherein: the rotatable member includes a hub having an internal cavity with an inner diameter and an outer diameter; the magnet is attached to the inner diameter of the internal cavity; and the ironless stator winding has a radial position with respect to the central axis that is external to the magnet and internal to the outer diameter of the internal cavity, and the winding has an axial position along the central axis that is within the internal cavity of the hub and common with the magnet.

Claim 19

Dependent Claim 58 words

The disc drive data storage system of claim 17 and further comprising a magnetic field focusing member which has a radial position that is external to the ironless stator winding with respect to the central axis and is magnetically coupled to the ironless stator winding for focusing a magnetic field between the ironless stator winding and the magnet.

Claim 20

Dependent Claim 104 words

The disc drive data storage system of claim 1 wherein: the rotatable member includes a hub having an internal cavity with an inner diameter and an outer diameter; the magnet includes a first magnet attached to the inner diameter of the internal cavity and a second magnet attached to the outer diameter of the internal cavity; and the ironless stator winding has a radial position with respect to the central axis that is external to the first magnet and internal to the second magnet, and the winding has an axial position along the central axis that is within the internal cavity of the hub.

Claim 21

Dependent Claim 34 words

The disc drive data storage system of claim 19 wherein the ironless stator winding has a cylindrical shape which is formed of a plurality of interwoven phase windings and is coaxial with the hub.

Claim 22

Dependent Claim 68 words

The disc drive data storage system of claim 19 and further comprising a radius extending from the central axis and being perpendicular to the central axis, wherein the ironless stator winding has a cylindrical shape which is formed of a plurality of phase windings, the phase windings being formed of wire loops which have a loop axis that is perpendicular to the radius and to the central axis.

Claim 23

Dependent Claim 137 words

The disc drive data storage system of claim 1 wherein: the rotatable member includes a hub having an internal cavity with an inner diameter and an outer diameter; the at least one magnet includes a first magnet positioned at the inner diameter of the internal cavity and a second magnet positioned at the outer diameter of the internal cavity; the ironless stator winding has a radial position with respect to the central axis that is external to the first magnet and internal to the second magnet, and the winding has an axial position along the central axis that is within the internal cavity of the hub; an overmold flowed over the ironless stator winding; and the hydrodynamic bearing has a first bearing surface formed by the first magnet and a second bearing surface formed by the overmold.

Claim 24

Dependent Claim 125 words

A disc drive data storage system, comprising: a housing; a central axis; a hub which is rotatable with respect to the central axis; at least one data storage disc attached to and coaxial with the hub; a magnet which is carried by the hub; a stator winding which is fixed with respect to the housing; an overmold flowed over the stator winding; a hydrodynamic bearing having a first radial bearing surface formed by the magnet and a second radial bearing surface formed by the overmold; and wherein the stator winding has an ironless structure which is magnetically coupled to the magnet such that the stator winding and the hydrodynamic bearing cooperate to reduce excitation of pure tone vibrations in the disc drive data storage system.

Claim 25

Dependent Claim 125 words

A disc drive data storage system, comprising: a housing; a central axis; a hub which is rotatable with respect to the central axis; at least one data storage disc attached to and coaxial with the hub; a magnet which is carried by the hub; a stator winding which is fixed with respect to the housing; an overmold flowed over the stator winding; a hydrodynamic bearing having a first radial bearing surface formed by the magnet and a second radial bearing surface formed by the overmold; and wherein the stator winding has an ironless structure which is magnetically coupled to the magnet such that the stator winding and the hydrodynamic bearing cooperate to reduce excitation of pure tone vibrations in the disc drive data storage system.

Claim 26

Dependent Claim 105 words

A hydrodynamic bearing spindle motor for a disc drive data storage system, comprising: a central axis; a housing; a stationary member which is fixed with respect to the housing; hub means for carrying at least one data storage disc and rotating the disc with respect to the central axis in response to a rotating magnetic field; hydrodynamic bearing means for interconnecting the hub means with the stationary member; and ironless stator winding means for generating the rotating magnetic field such that the ironless stator winding means and the hydrodynamic bearing means cooperate to reduce excitation of pure tone vibrations in the hydrodynamic bearing spindle motor.

Claim 27

Dependent Claim 105 words

A hydrodynamic bearing spindle motor for a disc drive data storage system, comprising: a central axis; a housing; a stationary member which is fixed with respect to the housing; hub means for carrying at least one data storage disc and rotating the disc with respect to the central axis in response to a rotating magnetic field; hydrodynamic bearing means for interconnecting the hub means with the stationary member; and ironless stator winding means for generating the rotating magnetic field such that the ironless stator winding means and the hydrodynamic bearing means cooperate to reduce excitation of pure tone vibrations in the hydrodynamic bearing spindle motor.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1999-11-26	2000-05-27	2000-11-26	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2003-11-26	2004-05-27	2004-11-26	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2007-11-26	2008-05-27	2008-11-26	$7700.00	Window Closed / Lapsed

Ironless spindle motor for disc drive

Abstract

Inventors

Bibliographic Details

Claims Analysis

References Cited (Backward Citations)

USPTO Annuity & Maintenance Windows

Assigned Categories & Tags

Assign Category Tag