Stator isolation for spindle motor

• US 5,619,389 A
• Filed: 02/10/1995
• Issued: 04/08/1997
• Est. Priority Date: 02/10/1995
• Status: Expired due to Term

• Current Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Original Assignee: Seagate Technology plc (Seagate Technology Holdings Plc)
• Inventors: Heine, Gunter K., Dunfield, John C.
• Primary Examiner(s): EVANS, JEFFERSON A
• Application Number:
  US08/386,883
• Time in Patent Office: 788 Days
• Field of Search: 360/97.01, 360/98.01, 360/98.07, 360/98.08, 360/99.04, 360/99.08-99.12, 360/254, 360/258, 310/51, 310/67 R
• US Class Current: 360/98.07
• CPC Class Codes: G11B 19/2018 Incorporating means for passive damping of vibration, either in the turntable, motor or mounting
• CPC Class Codes: G11B 25/043 using rotating discs
• CPC Class Codes: H02K 1/185 to outer stators
• CPC Class Codes: H02K 1/187 to inner stators

Abstract

A spindle motor for rotating at least one disc in a data storage device includes a base, a shaft, a rotor and a stator. A bearing interconnects the rotor with the shaft and allows the rotor to rotate about the shaft. A resilient coupling, such as an O-ring, is compressed between the stator and the base to mechanically isolate the stator from the base and thereby reduce the generation of acoustic noise in the storage device.

Claims

1. A spindle motor for rotating at least one disc about a central axis in a storage device, comprising:

a base having a side wall;

a stationary member attached to the base;

a hub comprising a rotor, wherein the hub is rotatable with respect to the stationary member;

a hydrodynamic bearing interconnecting the hub with the stationary member;

a stator radially positioned external to and coaxial with the rotor, wherein the stator has a side surface which is located at an outer diameter of the stator and is spaced from the base side wall in a radial direction with respect to the central axis; and

a resilient, vibration damping coupling compressed between the stator side surface and the base side wall in the radial direction.

2. The spindle motor of claim 1 wherein the resilient coupling includes a first coupling ring which is compressed between the side surface of the stator and the base side wall.

3. The spindle motor of claim 2 wherein the resilient coupling includes a second coupling ring which is compressed between the stator side surface and the base side wall and is spaced from the first coupling ring.

4. The spindle motor of claim 2 wherein:

the stator has an upper mounting surface;

the base has an upper mounting surface which is spaced laterally from the upper mounting surface of the stator; and

the resilient coupling further includes a damping bridge extending between and compressed against the upper mounting surfaces of the stator and base.

5. The spindle motor of claim 4 wherein the damping bridge comprises a damping ring of resilient material extending around a circumference of the stator.

6. The spindle motor of claim 4 wherein the damping bridge comprises:

a clamp which is secured to the base and is compressed against the upper mounting surfaces of the stator and the base.

7. The spindle motor of claim 4 wherein:

the stator has a lower mounting surface which is located generally opposite to the upper mounting surface of the stator; and

the resilient coupling further includes a second coupling ring compressed between the lower mounting surface of the stator and the base.

8. The spindle motor of claim 2 wherein:

the stator further includes a lower mounting surface which extends in a plane that is approximately normal to the stator side surface; and

wherein the resilient coupling further includes a second resilient coupling ring which is compressed between the lower mounting surface of the stator and the base, and wherein the first and second coupling rings cooperate to define a stator position within the base.

9. The spindle motor of claim 1 wherein:

the stator has a mounting surface;

the base has a mounting surface which is spaced laterally from the mounting surface of the stator; and

the spindle motor further comprises a metallic C-clamp secured to the base and extending between the mounting surfaces of the stator and the base.

10. The spindle motor of claim 1 wherein the resilient coupling is integrated in the stator.

11. The spindle motor of claim 10 wherein the resilient coupling comprises a resilient polymer material which is over-molded onto the stator and wherein the stator and over-molded polymer material are pressed into the base with the over-molded material being compressed against the base side wall.

12. A spindle motor for rotating at least one disc about a central axis in a storage device, comprising:

a base having a side wall;

a stationary member attached to the base;

a hub comprising a rotor, wherein the hub is rotatable with respect to the stationary member;

a hydrodynamic bearing interconnecting the hub with the stationary member;

a stator positioned within the base, axially below the hub with respect to the central axis and radially external to and coaxial with the rotor, wherein the stator has a side surface which is located at an outer diameter of the stator and is spaced from the base side wall;

a first resilient, vibration damping coupling which couples the stator and the base; and

a second resilient, vibration damping coupling which couples the stator and the base, wherein the second resilient coupling is spaced from the first resilient coupling in an axial direction with respect to the central axis.

13. The spindle motor of claim 12 wherein:

the first resilient coupling includes an O-ring which is positioned radially between the stator and the base with respect to the central axis; and

the second resilient coupling includes a resilient bridge which is compressed against the stator and the base in an axial direction with respect to the central axis.

14. The spindle motor of claim 12 wherein:

the first resilient coupling includes a first O-ring which positioned radially between the stator and the base with respect to the central axis; and

the second resilient coupling includes a second O-ring which positioned radially between the stator and the base with respect to the central axis.

15. A hydrodynamic bearing spindle motor for rotating at least one disc about a central axis in a data storage device, comprising:

a base having a side wall;

a stationary shaft attached to the base;

a rotor;

a hydrodynamic bearing positioned between the shaft and the rotor;

a stator radially positioned external to and coaxial with the rotor, wherein the stator has a side surface which is located at an outer diameter of the stator and is spaced from the base side wall in a radial direction with respect to the central axis; and

a first resilient O-ring compressed between the stator side surface and the base side wall in the radial direction.

16. The hydrodynamic bearing spindle motor of claim 15 and further comprising a second resilient O-ring which is compressed between the stator side surface and the base side wall and is spaced from the first resilient O-ring in an axial direction with respect to the central axis.

17. The hydrodynamic bearing spindle motor of claim 15 and further comprising a damping bridge extending from the stator to the base and compressed against the stator and the base in an axial direction with respect to the central axis.

18. The hydrodynamic bearing spindle motor of claim 15 and further comprising a resilient coupling compressed between the stator and the base in an axial direction with respect to the central axis.

19. A disc drive data storage system, comprising:

a housing having a base;

a central axis;

a stationary member attached to the base and coaxial with the central axis;

a rotatable member which is rotatable with respect to the stationary member;

a bearing interconnecting the rotatable member with the stationary member;

at least one data storage disc attached to and coaxial with the rotatable member;

a stator positioned within the base, axially below the rotatable member with respect to the central axis, and radially external to and coaxial with the rotor, wherein the stator has a side surface which is located at an outer diameter of the stator and is spaced from the base side wall in a radial direction with respect to the central axis;

a first resilient, vibration damping coupling which couples the stator and the base; and

a second resilient, vibration damping coupling which couples the stator and the base, wherein the second resilient coupling is spaced from the first resilient coupling in an axial direction with respect to the central axis.

20. A spindle motor for rotating at least one disc about a central axis in a storage device, comprising:

a base;

a stationary member attached to the base;

a hub comprising a rotor, wherein the hub is rotatable with respect to the stationary member;

a bearing interconnecting the hub with the stationary member;

a stator which is spaced from the base by a gap and which includes a stack of laminations; and

a resilient, vibration damping bridge formed of a polymeric material which extends across the gap from an upper surface of said stack of laminations to the base and is compressed against the stator and the base in an axial direction with respect to the central axis, wherein the resilient, vibration damping bridge forms a coupling between the stator and the base which inhibits transfer of vibrations between the stator and the base.