Over-mold stator assembly and process for preparation thereof

• US 20090167101A1
• Filed: 10/23/2008
• Published: 07/02/2009
• Est. Priority Date: 10/26/2007
• Status: Active Grant

• Current Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Original Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Inventors: Matsuzaki, Yoko, Saga, Yuji, Matsuzaki, Masahiro
• Granted Patent: US 7,939,975 B2
• Time in Patent Office: Days
• US Class Current: 310/45
• CPC Class Codes: H02K 15/12 Impregnating, heating or drying of windings, stators, rotors or machines
• CPC Class Codes: H02K 2203/12 Machines characterised by the bobbins for supporting the windings
• CPC Class Codes: H02K 3/325 for windings on salient poles, such as claw-shaped poles
• CPC Class Codes: H02K 3/522 for generally annular cores with salient poles
• CPC Class Codes: H02K 5/08 Insulating casings
• CPC Class Codes: H02K 9/227 Heat sinks
• CPC Class Codes: Y10T 29/49009 Dynamoelectric machine

Abstract

A stator assembly and a method for making a stator assembly wherein the stator assembly is over-molded with thermally conductive and electrically insulating polymer composition. The stator core of the stator assembly is coated with adhesive component to provide higher heat transfer at the interface of stator core and over-molded insulator and coil.

Claims

1. A stator assembly comprising

(a) a stator core comprising laminated electromagnetic steel sheets and further comprising wire wound coils;

(b) an over-molded insulator covering the stator core and being positioned between the stator core and the wire wound coils;

wherein the over-molded insulator comprises a thermally conductive polymer composition having a thermal conductivity of at least about 0.6 W/mK; and

(c) an adhesive component interfaced between the stator core a) and the over-molded insulator (b).

2. The stator assembly of claim 1 wherein the thermally conductive polymer composition comprises a base polymer and a filler material;

wherein the base polymer is selected from the group consisting of thermoplastic polymers and thermosetting polymers and the polymer contains groups that are reactive with the adhesive component (c).

3. The stator assembly of claim 2 wherein the thermally conductive polymer composition comprises of a thermoplastic polymer and a toughening agent.

4. The stator assembly of claim 1 wherein the adhesive component is a primer coated on the stator core (a).

5. The stator assembly of claim 4 wherein the primer comprises a coupling agent selected from the group consisting of silane, titanate, zirconate, aluminate and zircoaluminate.

6. The stator assembly of claim 5 wherein the thermally conductive polymer composition comprises a thermoplastic polymers having groups which can react with the coupling agents of the primer.

10. A motor comprising the stator assembly of claim 1.

11. A generator comprising the stator assembly of claim 1.

7. A process for forming a stator assembly of a stator core comprising laminated electromagnetic steel sheets and further comprising wire wound coils which comprises over-molding the stator core with an insulator covering between the stator core and the wire wound coils and applying an adhesive component between the stator core and the over-molded insulator covering;

wherein the insulator covering comprises a thermally conductive polymer composition having a thermal conductivity of at least about 0.6 W/mk.

8. The process of claim 7 wherein the thermally conductive polymer composition comprises a base polymer and a filler material;

wherein the base polymer is selected from the group consisting of thermoplastic polymers and thermosetting polymers and the thermally conductive polymer contains groups that are reactive with the adhesive component.

9. The process of claim 8 wherein the adhesive component is a primer comprising a coupling agent selected from the group consisting of silane, titanate, zirconate, aluminate, zircoaluminate.