Electric motor having a field assembly with slot insulation

• US 20050099085A1
• Filed: 09/03/2004
• Published: 05/12/2005
• Est. Priority Date: 09/05/2003
• Status: Active Grant

• Current Assignee: Black & Decker Incorporated (Stanley Black & Decker, Inc.)
• Original Assignee: Black & Decker Incorporated (Stanley Black & Decker, Inc.)
• Inventors: Du, Hung T., Verbrugge, Brandon L., Smith, David J., Zemlok, Michael A., Ortt, Earl M., Kusmierski, Robert G., Agnes, Michael J.
• Granted Patent: US 7,146,706 B2
• Time in Patent Office: Days
• US Class Current: 310/215
• CPC Class Codes: H02K 1/148 Sectional cores H02K1/141 takes precedence
• CPC Class Codes: H02K 1/18 Means for mounting or fastening magnetic stationary parts on to, or to, the stator structures
• CPC Class Codes: H02K 15/0435 Wound windings
• CPC Class Codes: H02K 15/10 Applying solid insulation to windings, stators or rotors
• CPC Class Codes: H02K 15/12 Impregnating, heating or drying of windings, stators, rotors or machines
• 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: Y10T 29/49009 Dynamoelectric machine
• CPC Class Codes: Y10T 29/49012 Rotor
• CPC Class Codes: Y10T 29/49071 by winding or coiling
• CPC Class Codes: Y10T 29/49073 by assembling coil and core
• CPC Class Codes: Y10T 29/53143 Motor or generator

Abstract

An electric motor has a field assembly, such as a stator, for a dynamoelectric machine has field coils that are wound to a net shape. Lead wires are brought out from the ends of each field coil. The field coils are insulated with insulating sleeves or insulating slot liners. The field coils are assembled with stator core pieces, such as pole pieces and return path pieces, into the stator. The stator core pieces are formed prior to being assembled with the field coils. In an aspect of the invention, the pole pieces and return path pieces are separately formed and then assembled together with the field coils, which have also been separately formed.

Claims

1. A method of making an electric motor, comprising:

a. forming field coils to a predetermined shape;

b. forming pole pieces and return path pieces;

c. placing an insulating sleeve over each portion of the field coil that will be disposed between one of the pole pieces and one of the return path pieces mated to that pole piece prior to placing the field coil on that pole piece and after forming the field coil to the predetermined shape;

d. placing the field coils with the insulating sleeves thereon on the pole pieces;

e. mating the pole pieces and return path pieces after placing the field coils on the pole pieces to form a stator; and

f. placing an armature in the stator.

2. The method of claim 1 including using a pliable adhesive strip disposed on a surface of each insulating sleeve that abuts one of the pole piece on which the insulating sleeve is placed and one of the return path pieces mated to that pole piece to take up clearances between that field coil and the one of the pole piece and return path piece abutting the surface of the insulating sleeve on which the adhesive strip is disposed.

3. The method of claim 2 including making the pliable adhesive strip so that it is smaller than a surface of the one of the pole piece and return path piece abutting the surface of the insulating sleeve on which the adhesive strip is disposed so that it is completely covered by said surface.

4. The method of claim 1 including using pliable adhesive strips disposed on surfaces of each insulating sleeve that abut the pole piece on which the insulating sleeve is placed and one of the return path pieces mated to that pole piece to take up clearances between the field coil on which the insulating sleeve is placed and the pole piece on which the field coil is placed and between that field coil and that return path piece.

5. The method of claim 1 including adhering each insulating sleeve to the field coil over which it is placed with at least one adhesive strip disposed on a surface of the insulating sleeve that abuts the field coil when the insulating sleeve is placed on the field coil.

6. The method of claim 1 including using adhesive strips disposed on inner and outer surfaces of each insulating sleeve to aid in retaining the field coils to the pole pieces on which they are placed and to the return path pieces mated to the pole pieces, to aid in holding together windings of the field coils on which the insulating sleeves are placed, and to aid in holding together each pole piece and the return path pieces mated to that pole piece.

7. The method of claim 1 including locating the insulating sleeves on the return path pieces and pole pieces with cuffed edges of the insulating sleeves that extend over axial edges of the return path pieces and pole tips of the pole pieces.

8. The method of claim 1 including capturing the insulating sleeves on the return path pieces and pole pieces with cuffed edges on opposed sides of the insulating sleeves that extend over opposed axial edges of the return path pieces and pole tips of the pole pieces.

9. The method of claim 1 including placing a pole tip of the pole piece on which the insulating sleeve is placed in a pocket of an outer surface of an inner section of the insulating sleeve.

10. The method of claim 1 including providing an interference fit between each field coil and at least one of the pole piece on which it is placed and one of the return path pieces mated to that pole piece with a compression rib on a surface of each insulating sleeve on that field coil that abuts at least one of the pole piece on which the insulating sleeve is placed and one of the return path pieces mated to that pole piece.

11. The method of claim 1 including forming each insulating sleeve out of liquid silicon rubber to have a pocket in an outer surface of an inner section of the insulating sleeve for receiving a pole tip of the pole piece on which the field coil having the insulating sleeve is placed and to have a compression rib on a surface that abuts a radially inner surface of one of the return path pieces mated to that pole piece, placing that pole tip in the pocket of the insulating sleeve and providing an interference fit between that field coil and that return path piece with the compression rib.

12. The method of claim 1 including forming each insulating sleeve to fit contours of the field coil on which it is placed and a radially outer surface of a pole tip of the pole piece which it abuts when that field coil is placed on that pole piece.

13. An electric motor, comprising:

a. a stator having separately formed pole pieces and return path pieces mated together;

b. field coils disposed on the pole pieces between the pole pieces and the return path pieces mated to the pole pieces;

c. each field coil having an insulating sleeve over each portion of the field coil that is disposed between the pole piece on which the field coil is disposed and one of the return path pieces mated to that pole piece;

d. a pliable adhesive strip disposed between a surface of each insulating sleeve and a surface of at least one of the pole piece and return path piece that abuts that surface of that insulating sleeve to take up clearances between the field coil having that insulating sleeve and that one of the pole piece and return path piece; and

e. an armature in the stator.

14. The electric motor of claim 13 wherein the pliable adhesive strip is smaller than the surface of that one of the pole piece and return path piece that abuts that surface of that insulating sleeve so that the pliable adhesive strip it is completely covered by that surface of that one of the pole piece and return path piece.

15. An electric motor, comprising:

a. a stator having separately formed pole pieces and return path pieces mated together;

b. field coils disposed on the pole pieces between the pole pieces and the return path pieces mated to the pole pieces;

c. each field coil having an insulating sleeve over each portion of the field coil that is disposed between the pole piece on which the field coil is disposed and one of the return path pieces mated to that pole piece;

d. pliable adhesive strips disposed on surfaces of each insulating sleeve that abut the pole piece and return path piece between which the insulating sleeve is disposed to take up clearances between the field coil having that insulating sleeve and that pole piece and that return path piece; and

e. an armature in the stator.

16. The electric motor of claim 15 including an adhesive strip disposed on a surface of each insulating sleeve that abuts the field coil when the insulating sleeve is placed on the field coil to adhere the insulating sleeve to that field coil.

17. The electric motor of claim 15 including adhesive strips disposed on inner and outer surfaces of each insulating sleeve to aid in retaining the field coils to the pole pieces on which they are placed and to the return path pieces mated to the pole pieces, to aid in holding together windings of the field coils on which the insulating sleeves are placed, and to aid in holding together each pole piece and the return path pieces mated to that pole piece.

18. The electric motor of claim 15 wherein the insulating sleeves include cuffed edges that extend over axial edges of the return path pieces and pole tips of the pole pieces.

19. The electric motor of claim 15 wherein an outer surface of an inner section of each insulating sleeve includes a pocket in which a pole tip of one of the pole pieces is received.

20. The electric motor of claim 15 wherein each insulating sleeve includes a compression rib on a surface that abuts one of the pole piece on which the field coil having that insulating sleeve is placed and one of the return pieces mated to that pole piece to provide an interference fit between that field coil and the one of the pole piece and return path piece.

21. The electric motor of claim 15 wherein each insulating sleeve fits contours of the field coil on which it is placed and a radially outer surface of a pole tip of the pole piece which it abuts.

22. A hand-held power tool, comprising a housing surrounding an electric motor, the electric motor including a stator and an armature in the stator, the stator including:

a. separately formed pole pieces and return path pieces mated together;

b. field coils disposed on the pole pieces between the pole pieces and the return path pieces mated to the pole pieces;

c. each field coil having an insulating sleeve over each portion of the field coil that is disposed between the pole piece on which the field coil is disposed and one of the return path pieces mated to that pole piece; and

d. pliable adhesive strips disposed on surfaces of each insulating sleeve that abut the pole piece and return path piece between which the insulating sleeve is disposed to take up clearances between the field coil having that insulating sleeve and that pole piece and that return path piece.

23. The power tool of claim 22 including an adhesive strip disposed on a surface of each insulating sleeve that abuts the field coil when the insulating sleeve is placed on the field coil to adhere the insulating sleeve to that field coil.

24. The power tool of claim 23 including adhesive strips disposed on inner and outer surfaces of each insulating sleeve to aid in retaining the field coils to the pole pieces on which they are placed and to the return path pieces mated to the pole pieces, to aid in holding together windings of the field coils on which the insulating sleeves are placed, and to aid in holding together each pole piece and the return path pieces mated to that pole piece.

25. The power tool of claim 23 wherein the insulating sleeves include cuffed edges that extend over axial edges of the return path pieces and pole tips of the pole pieces.

26. The power tool of claim 23 wherein an outer surface of an inner section of each insulating sleeve includes a pocket in which a pole tip of one of the pole pieces is received.

27. The power tool of claim 23 wherein each insulating sleeve includes a compression rib on a surface that abuts one of the pole piece on which the field coil having that insulating sleeve is placed and one of the return pieces mated to that pole piece to provide an interference fit between that field coil and the one of the pole piece and return path piece.

28. The power tool of claim 23 wherein each insulating slot liner fits contours of the field coil on which it is placed and a radially outer surface of a pole tip of the pole piece which it abuts.

29. A method of making an electric motor, comprising:

a. forming field coils to a predetermined shape;

b. forming pole pieces and return path pieces;

c. wrapping each portion of the field coil that will be disposed between one of the pole pieces and one of the return path pieces mated to that pole piece with an insulating slot liner made of insulation material having at least one of a B-stage thermosetting adhesive and a thermoplastic adhesive thereon prior to placing the field coil on that pole piece and after forming the field coil to the predetermined shape;

d. placing the field coils with the insulating slot liners thereon on the pole pieces;

e. mating the pole pieces and return path pieces after placing the field coils on the pole pieces to form a stator;

f. heating the field coils thus activating the adhesive which bonds the insulation material to the field coils and to the pole pieces and return path pieces to secure them together; and

g. placing an armature in the stator.

30. An electric motor, comprising a stator and a armature in the stator, the stator including:

a. separately formed pole pieces and return path pieces mated together;

b. field coils disposed on the pole pieces between the pole pieces and the return path pieces mated to the pole pieces; and

c. each portion of each field coil disposed between the pole piece on which the field coil is disposed and one of the return path pieces mated to that pole piece wrapped with an insulating slot liner made of a layer of insulation material with at least one of a B-stage thermosetting adhesive and a thermoplastic adhesive on at least one surface, the adhesive activated by heat during the assembly of the stator and bonding the insulation material to the field coil and the pole piece and return path piece to secure them together.

31. The motor of claim 30 wherein the insulation material has the adhesive on front and back surfaces.

32. A hand-held power tool, comprising a housing surrounding a motor, the motor including a stator and an apparatus in the stator, the stator including:

a. separately formed pole pieces and return path pieces mated together;

b. field coils disposed on the pole pieces between the pole pieces and the return path pieces mated to the pole pieces; and

c. each portion of each field coil disposed between the pole piece on which the field coil is disposed and one of the return path pieces mated to that pole piece wrapped with a insulating slot liner made of a layer of insulation material with at least one of a B-stage thermosetting adhesive and a thermoplastic adhesive on at least one surface, the adhesive activated by heat during the assembly of the stator and bonding the insulation material to the field coil and the pole piece and return path piece to secure them together.

33. The hand-held power tool of claim 32 wherein the insulation material has the adhesive on front and back surfaces.