Electro-permanent magnet mooring system

Patent metadata

Field	Value
Publication number	US-11380468-B2
Application number	US-201916533651-A
Country	US
Kind code	B2
Filing date	Aug 6, 2019
Priority date	Jun 19, 2018
Publication date	Jul 5, 2022
Grant date	Jul 5, 2022

Abstract

An electro-permanent magnet (EPM) for an electromagnetic mooring system (EMS) includes a low coercivity magnet surrounded by a reversible coil, and one or more high coercivity magnets surrounding the low coercivity magnet and the reversible coil. The reversible coil switches polarity of the low coercivity magnet to null the stronger, one or more high coercivity magnets. The nulling of the stronger, one or more high coercivity magnets allows for the EMS to connect and disconnect to an adjacent apparatus.

First claim

The invention claimed is:

1. An electro-permanent magnet (EPM) for an electromagnetic mooring system (EMS), comprising:
a low coercivity magnet surrounded by a reversible coil; and
one or more high coercivity magnets surrounding the low coercivity magnet and the reversible coil in a circular or ring pattern, wherein
the reversible coil is configured to switch polarity of the low coercivity magnet to null the one or more high coercivity magnets,
the nulling of the one or more high coercivity magnets allows for the EMS to connect and disconnect to an adjacent apparatus, and
the low coercivity magnet comprise of a single or an internal cylindrical Alnico magnet, and the one or more high coercivity magnets comprise of a ring of cylindrical Neodymium magnets.

2. The EPM of claim 1 , wherein the reversible coil is composed of copper.

3. The EPM of claim 1 , further comprising:
an outer ferromagnetic material encloses the low coercivity magnet, the reversible coil and the one or more high coercivity magnets, to mitigate stray magnetic fields created by the EPM.

4. The EPM of claim 3 , wherein the outer ferromagnetic material comprises a coating to prevent cold welding, ensuring connecting and disconnecting of the EPM to the adjacent apparatus.

5. The EPM of claim 1 , wherein, when the EPM is switched on, the reversible coil creates a magnetic field in opposite polarity of a current polarity of the low coercivity magnet with strength to switch polarity of the low coercivity magnet.

6. The EPM of claim 1 , wherein, when the EPM is in an ON state, flux is routed from the low coercivity magnet and the one or more high coercivity magnets into an inner ferromagnetic material.

7. The EPM of claim 6 , wherein, when the EPM is in the ON state, the flux crosses to an external ferromagnetic clamp, the external ferromagnetic clamp generating desired mooring forces,
the desired mooring force is an attractive force generated by the flux as magnetic force passes from the inner ferromagnetic material to the external ferromagnetic clamp.

8. The EPM of claim 7 , wherein, when the EPM is in the ON state, the flux returns to an outer ferromagnetic material and to the opposite pole of the low coercivity magnet and the one or more high coercivity magnets to complete the magnetic circuit.

9. The EPM of claim 1 , wherein, when the EPM is in an OFF state, a pole of the low coercivity magnet is reversed to route flux into an inner ferromagnetic material, the flux being routed by way of the one or more high coercivity magnets.

10. The EPM of claim 9 , wherein the flux is routed through the low coercivity magnet into a portion of an outer ferromagnetic material, the portion being near the low coercivity magnet and the one or more high coercivity magnets.

11. The EPM of claim 10 , wherein, the flux is routed back into the one or more high coercivity magnets to complete a magnetic circuit.

12. An apparatus for an electromagnetic mooring system (EMS), comprising:
a reversible coil surrounding a low coercivity magnet, configured to switch polarity of the low coercivity magnet to null one or more high coercivity magnets, wherein
the switching of the polarity allows for the EMS to connect and disconnect with an adjacent vehicle, and
the low coercivity magnet comprise of a single or an internal cylindrical Alnico magnet, and the one or more high coercivity magnets comprise of a ring of cylindrical Neodymium magnets.

13. The apparatus of claim 12 , further comprising:
an outer ferromagnetic material enclosing the low coercivity magnet, the reversible coil, and the one or more high coercivity magnets, configured to create a magnetic flux return path capturing magnetic flux in the outer ferromagnetic material and mitigate stray magnetic fields created by the apparatus.

14. The apparatus of claim 12 , further comprising:
a coating composed of molybdenum disulfide applied to outer magnetic ferromagnetic material prevents cold welding.

15. The apparatus of claim 12 , wherein the low coercivity magnet and the reversible coil controls state of the apparatus, wherein the state comprises an ON state and an OFF state.

16. The apparatus of claim 15 , wherein, during the ON state,
magnetic flux is routed from the low coercivity magnet and the one or more high coercivity magnets into inner ferromagnetic material,
the magnetic flux further crosses to an external ferromagnetic clamp generating mooring forces, and
the magnetic flux returns to an outer ferromagnetic material and to opposite pole of the low coercivity magnet and the one or more high coercivity magnets to complete a magnetic circuit.

17. The apparatus of claim 15 , wherein, during the OFF state,
the flux is routed by the one or more high coercivity magnets and through the low coercivity magnet into a portion of an outer ferromagnetic material, the portion being located near the low coercivity magnet and the one or more high coercivity magnets, and
flux being routed back into the one or more high coercivity magnets to complete a magnetic circuit.

Assignees

• Aerospace Corp

Inventors

• Denham Donald Wayne

Classifications

• B64G1/642

  Clamps, e.g. Marman clamps · CPC title

• B64G1/645

  Separators · CPC title

• B63B21/02

  Magnetic mooring equipment · CPC title

• H01F7/0205

  Magnetic circuits with PM in general · CPC title

• H01F7/20

  without armatures (cores H01F3/00; coils H01F5/00 {; shaping metal by applying magnetic forces B21D26/14; electromagnets specially adapted for NMR applications G01R33/381}) · CPC title