Method for mitigating thermal aging of permanent magnets in organic liquid

Patent metadata

Field	Value
Publication number	US-10141795-B2
Application number	US-201615064211-A
Country	US
Kind code	B2
Filing date	Mar 8, 2016
Priority date	Apr 20, 2015
Publication date	Nov 27, 2018
Grant date	Nov 27, 2018

Abstract

An electric motor is provided for use in an electromechanical transmission that utilizes automatic transmission fluid. The electric motor includes a stator and a rotor. The rotor includes a plurality of permanent magnets can include magnetic particles coated with hydrogen impermeable material. According to an alternative embodiment, the entire permanent magnet or the rotor itself can be coated with hydrogen impermeable material. According to a further alternative embodiment, the permanent magnet particles can be secured by a binder that includes a hydrogen storage compound that prevents hydrogen from affecting magnetic properties of the permanent magnet.

First claim

What is claimed is:

1. An electric motor, comprising:
a stator;
a rotor including a plurality of magnets, said magnets having individual magnetic particles that are coated with a pinhole-free coating of hydrogen impermeable material sufficient to prevent hydrogen from permeating the hydrogen impermeable material to the magnetic particles.

2. The electric motor according to claim 1 , wherein the hydrogen impermeable material includes a metal or metal containing compound.

3. The electric motor according to claim 2 , wherein the metal or metal containing compound includes at least one of Cu, Ni, FeTi, NiTi, Al, Al 2 O 3 , AlSi, TiC, TiN, TiO 2 , SiC, W, BN, Mo, Sn, Cr, Cr 2 O 3 .

4. The electric motor according to claim 1 , wherein the hydrogen impermeable material includes a dense high temperature polymer.

5. The electric motor according to claim 4 , wherein the dense high temperature polymer includes at least one of fluorpolymerpolyethylene terephthalate, parylene, ethylene tetrachloroethylene, chlorotrifluoroethylene, polypyrole, polyether etherketone, polysulfone, polyamide, and polyimide.

6. The electric motor according to claim 1 , wherein the hydrogen impermeable material includes at least one of a graphitic carbon, graphene, reduced graphene oxide.

7. An electric motor, comprising:
a stator;
a rotor including a plurality of magnets, said magnets being individually coated with a pinhole-free coating of hydrogen impermeable material sufficient to prevent hydrogen from permeating the hydrogen impermeable material to the magnets.

8. The electric motor according to claim 7 , wherein the hydrogen impermeable material includes a metal or metal containing compound.

9. The electric motor according to claim 8 , wherein the metal or metal containing compound includes at least one of Cu, Ni, FeTi, NiTi, Al, Al 2 O 3 , AlSi, TiC, TiN, TiO 2 , SiC, W, BN, Mo, Sn, Cr, Cr 2 O 3 .

10. The electric motor according to claim 7 , wherein the hydrogen impermeable material includes a dense high temperature polymer.

11. The electric motor according to claim 10 , wherein the dense high temperature polymer includes at least one of fluoropolymer, polyethylene terephthalate, parylene, ethylene tetrachloroethylene, chloro-trifluoroethylene, polypyrole, polyether etherketone, polysulfone, polyamide, and polyimide.

12. The electric motor according to claim 7 , wherein the hydrogen impermeable material includes at least one of a graphitic carbon, graphene, reduced graphene oxide.

13. An electric motor, comprising:
a stator;
a rotor including a plurality of magnets, said rotor being coated with a pinhole-free coating of hydrogen impermeable material sufficient to prevent hydrogen from permeating the hydrogen impermeable material to the magnets.

14. The electric motor according to claim 13 , wherein the hydrogen impermeable material includes a metal or metal containing compound.

15. The electric motor according to claim 14 , wherein the metal or metal containing compound includes at least one of Cu, Ni, FeTi, NiTi, Al, Al 2 O 3 , AlSi, TiC, TiN, TiO 2 , SiC, W, BN, Mo, Sn, Cr, Cr 2 O 3 .

16. The electric motor according to claim 13 , wherein the hydrogen impermeable material includes a dense high temperature polymer.

17. The electric motor according to claim 16 , wherein the dense high temperature polymer includes at least one of fluoropolymer, polyethylene terephthalate, parylene, ethylene tetrachloroethylene, chloro-trifluoroethylene, polypyrole, polyether etherketone, polysulfone, polyamide, and polyimide.

18. The electric motor according to claim 13 , wherein the hydrogen impermeable material includes at least one of a graphitic carbon, graphene, reduced graphene oxide.

19. An electric motor, comprising:
a stator;
a rotor including a plurality of magnets, said magnets having magnetic particles held together with a binder material, wherein the binder material includes a hydrogen storage compound.

20. The electric motor according to claim 19 , wherein the hydrogen storage compound includes one of LaNi 5 and Mg 2 Ni.

Assignees

• Gm Global Tech Operations Llc

Inventors

• Thompson Margarita P
• Pinkerton Frederick E
• Balogh Michael P
• Dadheech Gayatri Vyas
• Zeng Xiaoqing

Classifications

• H01F1/061

  with a protective layer · CPC title

• H01F1/0571

  in the form of particles, e.g. rapid quenched powders or ribbon flakes · CPC title

• H02K1/02 Primary

  characterised by the magnetic material · CPC title