Rotation-speed-independent stabilizer for passive magnetic bearing systems

Patent metadata

Field	Value
Publication number	US-2016102704-A1
Application number	US-201414512280-A
Country	US
Kind code	A1
Filing date	Oct 10, 2014
Priority date	Oct 10, 2014
Publication date	Apr 14, 2016
Grant date	—

Abstract

By employing a combination of magnetic forces and those from electrostatic fields, a new stabilizer is able, unlike those employing dynamic effects, to function at any speed with no need for sensors or dynamically generated electrical currents. Embodiments are provided that stabilize the radial, axial and tilt instability. In addition to its use for stabilization, the radial stabilizer described herein also functions as an eccentricity detector.

First claim

We claim:

1 . An apparatus, comprising:
a rotatable cylinder having a central longitudinal axis; means for utilizing static electrostatic forces to stabilize at least one instability of said cylinder, wherein said at least one instability is selected from the group consisting of radial, axial and tilt; and means for utilizing magnetic forces between permanent magnets to stabilize any instability of said group that is not stabilized by said static electrostatic forces.

2 . The apparatus of claim 1 , wherein said means for utilizing static electrostatic forces to stabilize at least one instability of said cylinder comprises:
a first ring centered on said axis, concentric with, fixedly attached to, and electrically isolated from said cylinder, said first ring having a first diameter and comprising material selected from the group consisting of dielectric or metal; a stationary second ring centered on said axis, concentric with said cylinder and having a second diameter about equal to or overlapping said first diameter and comprising metal; a stationary third ring centered on said axis, concentric with said cylinder and having a third diameter about equal to or overlapping said first diameter and comprising metal, wherein said first ring is between and spaced from said second ring and said third ring; and a first power supply having a first lead and a second lead, wherein said first lead is connected to said second ring and said second lead is connected to said third ring.

3 . The apparatus of claim 2 , wherein said first ring comprises a first group of rings, wherein said second ring comprises a second group of rings and wherein said third ring comprises a third group of rings.

4 . The apparatus of claim 2 , wherein said first power supply is selected from a group consisting of a source of dc voltage and a source of rf voltage.

5 . The apparatus of claim 2 , wherein said first ring is located above the center line of said cylinder.

6 . The apparatus of claim 5 , further comprising a fifth ring having the same configuration as said first ring, wherein said fifth ring is located below the center line of said cylinder by the same distance as said first ring is located above said centerline, wherein said apparatus further comprises a sixth ring having the same configuration as said second ring but located with respect to said fifth ring and wherein said apparatus further comprises a seventh ring having the same configuration as said third ring but located with respect to said fifth ring, wherein said apparatus utilizes either (i) said first power supply connected to said sixth and said seventh ring in the same manner as said first power supply is connected to said second ring and said third ring respectively or (ii) a second power supply connected to said sixth ring and said seventh ring in the same manner as said first power supply is connected in (ii).

7 . The apparatus of claim 2 , wherein said first ring is located above the top of said rotor.

8 . The apparatus of claim 2 , wherein said first ring is attached to said cylinder with a support rod attached to said cylinder by a support structure which spans said cylinder, wherein said support rod is fixed to be coaxial with the said longitudinal axis.

9 . The apparatus of claim 1 , wherein said means for utilizing static electrostatic forces to stabilize at least one instability of said cylinder comprises:
a first ring centered on said axis, concentric with, fixedly attached to, and electrically isolated from said cylinder, said first ring having a first diameter and comprising material selected from the group consisting of dielectric or metal; a stationary second ring centered on said axis, concentric with said cylinder and having a second diameter greater than said first diameter, wherein said second ring comprises metal; a stationary third ring centered on said axis, concentric with said cylinder and having a third diameter less than said first diameter, wherein said third ring comprises metal, wherein said first ring is between and spaced from said second ring and said third ring, wherein said first ring and said second ring and said third ring are all located such that they overlap on a plane perpendicular with said central longitudinal axis; and a power supply having a first lead and a second lead, wherein said first lead is connected to said second ring and said second lead is connected to said third ring.

10 . The apparatus of claim 9 , wherein said first ring comprises a first group of rings, wherein said second ring comprises a second group of rings and wherein said third ring comprises a third group of rings.

11 . The apparatus of claim 9 , wherein said first power supply is selected from a group consisting of a source of dc voltage and a source of rf voltage.

12 . The apparatus of claim 9 , wherein said first ring is located above the centerline of said cylinder.

13 . The apparatus of claim 12 , further comprising a fifth ring having the same configuration as said first ring, wherein said fifth ring is located below the center line of said cylinder by the same distance as said first ring is located above said centerline, wherein said apparatus further comprises a sixth ring having the same configuration as said second ring but located with respect to said fifth ring and wherein said apparatus further comprises a seventh ring having the same configuration as said third ring but located with respect to said fifth ring, wherein said apparatus utilizes either (i) said first power supply connected to said sixth and said seventh ring in the same manner as said first power supply is connected to said second ring and said third ring respectively or (ii) a second power supply connected to said sixth ring and said seventh ring in the same manner as said first power supply is connected in (ii).

14 . The apparatus of claim 9 , wherein said first ring is located above the top of said rotor.

15 . The apparatus of claim 9 , wherein said first ring is attached to said cylinder with a support rod attached to said cylinder by a support structure which spans said cylinder, wherein said support rod is fixed to be coaxial with the said longitudinal axis.

16 . A method, comprising:
providing a rotatable cylinder having a central longitudinal axis; utilizing static electrostatic forces to stabilize at least one instability of said cylinder, wherein said at least one instability is selected from the group consisting of radial, axial and tilt; and utilizing magnetic forces between permanent magnets to stabilize any instability of said group that is not stabilized by said static electrostatic forces.

17 . The method of claim 16 , wherein the step of utilizing static electrostatic forces to stabilize at least one instability of said cylinder is carried out with the apparatus of claim 2 , further comprising providing voltage from said first power supply to said second ring and said third ring.

18 . The method of claim 17 , wherein said first ring comprises a first group of rings, wherein said second ring comprises a second group of rings and wherein said third ring comprises a third group of rings.

19 . The method of claim 17 , wherein said first power supply is selected from a group consisting of a source of dc voltage and a source of rf voltage.

20 . The method of claim 17 , wherein said first ring is located above the center line of said cylinder.

21 . The method of claim 20 , wherein said apparatus further comprises a

Assignees

• L Livermore Nat Security Llc

Inventors

• Post Richard F

Classifications

• F16C32/0404 Primary

  Electrostatic bearings · CPC title

• F16C32/0408

  Passive magnetic bearings · CPC title