Stator slot liners

• US 9,641,037 B2
• Filed: 08/28/2014
• Issued: 05/02/2017
• Est. Priority Date: 08/28/2014
• Status: Active Grant

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Zhang, Wei, Zhao, RiAn, Fang, Xiaomei, Littlejohn, Matthew Hal
• Primary Examiner(s): NGUYEN, TRAN N
• Application Number:
  US14/471,488
• Publication Number:
  US 20160065025A1
• Time in Patent Office: 978 Days
• Field of Search: 310215
• CPC Class Codes: B29C 70/025 with particular filler
• CPC Class Codes: B29C 70/688 the inserts being meshes or lattices B29C70/82, B29C70/683 take precedence
• CPC Class Codes: B29C 70/88 characterised primarily by possessing specific properties, e.g. electrically conductive or locally reinforced
• CPC Class Codes: B29L 2031/34 Electrical apparatus, e.g. sparking plugs or parts thereof
• CPC Class Codes: H02K 15/04 of windings, prior to mounting into machines insulating windings H02K15/10, H02K15/12
• CPC Class Codes: H02K 15/10 Applying solid insulation to windings, stators or rotors
• CPC Class Codes: H02K 3/30 Windings characterised by the insulating material
• CPC Class Codes: H02K 3/345 between conductor and core, e.g. slot insulation

Abstract

A slot liner for a stator assembly in one embodiment includes a mesh structural member and a coating. The coating is disposed on at least one side of the mesh structural member, and includes a mixture of a filler and a polyimide resin. The filler is a high thermal conductivity electrical insulating (HTCEI) filler, and includes particles of at least one of boron nitride, aluminum nitride, or a diamond material.

Claims

1. A slot liner for a stator assembly of a power system, the slot liner comprising:

a mesh structural member; and

a coating disposed on at least one side of the mesh structural member, the coating comprising a mixture of

a high thermal conductivity electrical insulating (HTCEI) filler, the HTCEI filler comprising particles of at least one of boron nitride, aluminum nitride, or a diamond material; and

a polyimide resin.

2. The slot liner of claim 1, wherein the particles of the filler comprise boron nitride particles having a size between 100 nanometers and 300 nanometers, and the mesh structural member is configured to accept the size of the particles.

3. The slot liner of claim 1, wherein the particles of the filler comprise boron nitride particles having a size between 10 nanometers and 100 microns, and the mesh structural member is configured to accept the size of the particles.

4. The slot liner of claim 1, wherein the mesh structural member comprises a mesh formed with a polyether ether ketone (PEEK) material.

5. The slot liner of claim 1, wherein the mesh structural member comprises a mesh formed with a yarn made of a NOMEX®

material.

6. The slot liner of claim 1, wherein the liner is generally U-shaped and includes at least one bend of about 90 degrees when positioned in the stator.

7. The slot liner of claim 1, wherein the polyimide resin comprises between 50 and 65 percent of the coating by weight.

8. The slot liner of claim 1, wherein the coating is disposed on two opposite sides of the mesh structural member.

9. A stator assembly for a power system, the stator assembly comprising:

an annular member defining a bore;

slots formed in the annular member having openings extending toward the bore;

windings passing through the slots; and

slot liners disposed in the slots and interposed between the windings and the annular member, wherein the slot liners comprise;

a mesh structural member; and

a coating disposed on at least one side of the mesh structural member, the coating comprising a mixture of

a high thermal conductivity electrical insulating (HTCEI) filler, the HTCEI filler comprising particles of at least one of boron nitride, aluminum nitride, or a diamond material; and

a polyimide resin.

10. The stator assembly of claim 9, wherein the particles of the filler comprise boron nitride particles having a size between 10 nanometers and 100 microns and the mesh structural member is configured to accept the size of the particles.

11. The stator assembly of claim 9, wherein the mesh structural member comprises a mesh formed with at least one of a polyether ether ketone (PEEK) material or a NOMEX®

material, and wherein the liner is generally U-shaped and includes at least one bend of about 90 degrees when positioned in one of the slots of the stator.

12. The stator assembly of claim 9, wherein the polyimide resin comprises between 50 and 65 percent of the coating by weight.

13. A method comprising:

providing a mesh structural member, a polyimide resin precursor, and a high thermal conductivity electrical insulating (HTCEI) filler, the HTCEI filler comprising particles of at least one of boron nitride, aluminum nitride, or a diamond material;

mixing the polyimide resin precursor and the HTCEI filler to provide a coating;

coating at least one side of the mesh structural member with the coating to provide a liner material;

curing the liner material; and

forming the liner material into a shape configured to be accepted by a slot of a stator assembly.

14. The method of claim 13, wherein mixing the polyimide resin precursor and the HTCEI filler comprises using an amount of the polyimide resin precursor to provide a coating in which a polyimide resin comprises between 50 and 65 percent of the coating by weight.

15. The method of claim 13, wherein the particles of the filler comprise boron nitride particles having a size between 10 nanometers and 100 microns, and the mesh structural member is configured to accept the size of the particles.

16. The method of claim 13, wherein the particles of the filler comprise boron nitride particles having a size between 100 nanometers and 300 nanometers, and the mesh structural member is configured to accept the size of the particles.

17. The method of claim 13, wherein forming the liner material comprises applying heat and pressure to the liner material.

18. The method of claim 17, wherein the mesh structural member comprises a mesh formed with at least one of a polyether ether ketone (PEEK) material or a NOMEX®

material, and wherein forming the liner material comprises forming the liner material into a generally U-shaped structure having at least one bend of about 90 degrees.

19. The method of claim 13, further comprising pre-treating the mesh structural member before coating at least one side of the mesh structural member, wherein pre-treating comprises applying a hexane rinse and plasma treatment.

20. The method of claim 13, wherein the coating at least one side of the mesh structural member comprises:

applying a first coat of the coating to a substrate;

applying the mesh structural member with a first surface oriented toward the first coat of the coating and a second surface opposite the first surface; and

applying a second coat of the coating to the second surface of the mesh structural member.