Stator assembly made from a molded web of core segments and motor using same

• US 20060238063A1
• Filed: 06/26/2006
• Published: 10/26/2006
• Est. Priority Date: 03/02/2001
• Status: Active Grant

• Current Assignee: Intellectual Ventures II LLC (Intellectual Ventures LLC)
• Original Assignee: Encap Motor Corporation
• Inventors: Neal, Griffith D.
• Granted Patent: US 7,262,527 B2
• Time in Patent Office: Days
• US Class Current: 310/43
• CPC Class Codes: G11B 19/2009 Turntables, hubs and motors for disk drives; Mounting of motors in the drive means for clamping of disk to turntable G11B17/022 and subgroups
• CPC Class Codes: H02K 1/148 Sectional cores H02K1/141 takes precedence
• CPC Class Codes: H02K 15/022 with salient poles or claw-shaped poles
• CPC Class Codes: H02K 15/095 by laying conductors around salient poles
• CPC Class Codes: H02K 15/12 Impregnating, heating or drying of windings, stators, rotors or machines
• CPC Class Codes: H02K 2203/06 Machines characterised by the wiring leads, i.e. conducting wires for connecting the winding terminations
• 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 5/1737 radially supporting the rotor around a fixed spindle; radially supporting the rotor directly
• CPC Class Codes: Y10T 29/49009 Dynamoelectric machine
• CPC Class Codes: Y10T 29/49011 Commutator or slip ring assembly
• CPC Class Codes: Y10T 29/49012 Rotor
• CPC Class Codes: Y10T 29/49073 by assembling coil and core
• CPC Class Codes: Y10T 29/53143 Motor or generator

Abstract

A plurality of stator segments 20 are linked together by a phase change material 22 enabling simplified winding and higher slot fill. Once wound this continuous structure can be formed into a toroidal core 17 for a stator assembly 40 used to make a motor 100. In a preferred embodiment, a monolithic body 42 of phase change material substantially encapsulates the conductors and holds the stator segments 20 in contact with each other in the toroidal core 17. Hard disc drives using the motor 100, and methods of constructing the motor 100 are also disclosed.

Claims

1. A method of making a stator assembly comprising:

a) providing a plurality of discrete stator segments each having at least one pole, the segments having a first side surface and a second side surface, and each being at least partially encased with a phase change material, wherein the phase change material also comprises a bridge between adjacent segments to link adjacent segments into a continuous strip;

b) winding wire on the poles;

c) aligning said stator segments to form a toroidal core, wherein each said side surface of one segment is adjacent an opposing side surface of another segment; and

d) placing a retaining member on the exterior of the toroidal core to unitize the structure.

2. The method of claim 1 wherein a thin film of phase change material exits where the side surface of one segment is adjacent the opposing side surface of another segment.

3. The method of claim 1 wherein edges of the phase change material create a gap where the side surface of one segment is adjacent the opposing side surface of another segment.

4. The method of claim 1 wherein the stator segments are made from steel lamination stacks and the steel of one stack contacts the steel of another stack where the side surface of one segment is adjacent the opposing side surface of another segment.

5. The method of claim 1 wherein the poles each have a face and the phase change material covers the sides of the poles such that the pole faces and phase change material between pole faces form a continuous surface when formed into a toroidal shape.

6. The method of claim 1 wherein the phase change material is selected from the group consisting of polyamides and polyesters.

7. The method of claim 1 wherein the phase change material has guides integrally formed in the phase change material to position the wire and prevent its movement in relation to the stator segments.

8. The method of claim 7 wherein the guides comprises flanges and posts.

9. The method of claim 1 wherein the phase change material has a thermal conductivity of at least 0.4 watts/meter°

K at 23°

C.

10. The method of claim 1 wherein enhancement magnets are also substantially encapsulated in the phase change material.

11. The method of claim 1 wherein the phase change material linking adjoining segments has a length X, wherein X is the length of uncoiled wire necessary to align said stator segments to form said toroidal core.

12. The method of claim 1 wherein said phase change material is selected from the group consisting of thermoplastics and thermosetting materials.

13. The method of claim 1 wherein the phase change material positions and holds terminals.

14. The method of claim 1 where the retaining member comprises a metal band.

15. The method of claim 1 wherein the stator segments are unitized by an overmolded thermoplastic material.

16. The method of claim 1 wherein the bridges produce such a continuous linkage between segments that the bridges may be used to orient and manipulate the segments during wire winding.

17. The method of claim 1 wherein the phase change material comprises an injection molded thermoplastic material.

18. A motor incorporating a stator assembly made by the method of claim 1.

19. A piece of equipment incorporating the motor of claim 18.

20. The motor of claim 18 wherein the phase change material is shaped to include features for mounting the motor.

21. A method of making a stator assembly comprising:

a) providing a plurality of discrete stator segments each having at least one pole and each at least being partially encased with a phase change material, wherein the phase change material also comprises a bridge between adjacent segments linking adjacent segments into a continuous strip;

b) winding wire on each pole of each stator segment; and

c) arranging and securing the linked stator segments together to form the stator assembly.

22. The method of claim 21 wherein each of said stator segments comprise a plurality of discrete steel laminations held together by the phase change material.

23. A motor incorporating a stator assembly made by the method of claim 21.

24. The method of claim 21 wherein the bridge linking the stator segments together is assembled by interconnecting sections of the bridge formed from the phase change material.

25. The method of claim 21 wherein the stator segments at least partially encased with a phase change material are provided by injection molding a thermoplastic around the stator segments in a mold tool, and the bridge linking the stator segments is made by inserting a section of plastic webbing of a segment molded in a prior cycle into the mold tool before a new segment is to be molded, such that the phase change material encasing the new segment locks with the webbing from the prior cycle, thus making a continuous strip.

34. The method of claim 21 wherein the bridges between adjoining segments can be used to orient and position wire relative to the poles.

26. A method of making a stator assembly comprising:

a) providing multiple lamination stacks;

b) placing the lamination stacks in an injection mold and injecting a thermoplastic material into the mold to producing a plurality of stator segments linked together by a monolithic webbing of the thermoplastic material, each segment constituting at least one pole and having a first side surface and a second side surface;

c) winding wire on the poles; and

d) aligning said stator segments to form a toroidal core, wherein each said side surface of one segment is adjacent an opposing side surface of another segment.

27. A method of making a motor comprising the steps of making a stator assembly using the method of claim 26 and constructing the stator assembly into a motor.

28. A method of making a compressor comprising the steps of making a stator assembly using the method of claim 26 and constructing the stator assembly into a compressor.

29. A method of making a pump comprising the steps of making a stator assembly using the method of claim 26 and constructing the stator assembly into a pump.

30. The method of claim 26 further comprising the step of substantially encapsulating the toroidal core with a monolithic body of phase change material.

31. The method of claim 30 wherein the phase change material is injection molded.

32. The method of claim 31 wherein the phase change material forming the monolithic body has a coefficient of thermal expansion of less than 2×

10<sup>−

5</sup> in/in/OF throughout the range of 0-250°

F.

33. The method of claim 26 wherein segments molded in step b) contain less than the total number of poles in the stator assembly, and each segment includes a section of webbing extending there from, and multiple segments are connected together by connecting said sections of webbing.