Power tools with motor having a multi-piece stator

• US 8,207,647 B2
• Filed: 01/14/2011
• Issued: 06/26/2012
• 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., Ortt, Earl M., Verbrugge, Brandon L., Mccormick, Garrett P., Zemlock, Michael A., Samuelsen, Eric J., Hogan, Kevin M., Zhang, Jiaqi, Wang, Ren H., Bernstein, Eric L., Mannarino, Frank A., Smith, Allison A., Rakosky, Therese M., Wheaton, Kyle J., Nicolaidis, Antonios M., Moll, Shane Ashley
• Primary Examiner(s): LE, DANG D
• Application Number:
  US13/006,473
• Publication Number:
  US 20110115314A1
• Time in Patent Office: 529 Days
• Field of Search: 310/47, 310/50, 310/89, 310/216.028, 310/216.091
• US Class Current: 310/216.091
• CPC Class Codes: H02K 1/14 Stator cores with salient poles
• 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 3/325 for windings on salient poles, such as claw-shaped poles
• CPC Class Codes: H02K 3/46 Fastening of windings on the stator or rotor structure
• CPC Class Codes: H02K 7/145 Hand-held machine tool

Abstract

A power tool has a motor having a stator made by separately forming pole pieces, return path pieces and field coils. The field coils are placed over necks of the pole path pieces and the return path pieces are affixed to the pole pieces. An armature having an outside diameter of at least 0.625 the outside diameter of the stator is placed in the stator. The field coils may be formed so that they extend beyond pole tips of the pole pieces.

Claims

1. A hand-held power tool, comprising:

a housing in which an electric motor of a predetermined frame size is disposed, the motor including;

a stator having a lamination stack having pole pieces mated to return path pieces and field coils disposed on the pole pieces;

an armature disposed in the stator, the armature having an outside diameter that is at least 0.625 of an outside diameter of the stator;

a length of the lamination stack of the stator being at least ten percent shorter than a length of a lamination stack of a stator of a needle wound motor of the same frame size wherein the lamination stack of the stator of the needle wound motor includes a plurality of individual of laminations stacked together wherein each of the laminations includes slots in which magnet wires are wound to wind field coils; and

the motor having a maximum power output that is at least the same as a maximum power output of the needle wound motor of the same frame size with the longer lamination stack where both motors have the same maximum no load speed.

2. The apparatus of claim 1 wherein the hand-held power tool is a large angle grinder.

3. The apparatus of claim 2 wherein the stator has an outside diameter of no more than 95 mm and a stack length of no more than 35 mm, and with a maximum no-load speed of 23,500 rpm the motor provides at least 3000 maximum watts out.

4. The apparatus of claim 2 wherein the stator has an outside diameter of no more than 95 mm and a stack length of no more than 45 mm, and with a maximum no-load speed of 23,500 rpm the motor provides at least 3700 maximum watts out.

5. The apparatus of claim 1 wherein the hand-held power tool is a small angle grinder with the stator having an outside diameter of no more than 55 mm and a stack length of no more than 48 mm, and with a maximum no-load speed of 38,000 rpm the motor provides at least 1200 maximum watts out.

6. The apparatus of claim 1 wherein the hand-held power tool is a circular saw.

7. The apparatus of claim 6 wherein the stator has an outside diameter of no more than 95 mm and a stack length of no more than 30 mm, and with a maximum no-load speed of 24,500 rpm the motor provides at least 2,125 maximum watts out.

8. The apparatus of claim 1 wherein the hand-held power tool is a miter saw.

9. The apparatus of claim 8 wherein the stator has an outside diameter of no more than 95 mm and a stack length of no more than 35 mm, and with a maximum no-load speed of 25,000 rpm the motor provides at least 2,350 maximum watts out.

10. The apparatus of claim 1 wherein the hand-held power tool is a chop saw.

11. The apparatus of claim 10 wherein the stator has an outside diameter of no more than 95 mm and a stack length of no more than 48 mm, and with a maximum no-load speed of 25,000 rpm the motor provides at least 3,200 maximum watts out.

12. The apparatus of claim 1 wherein the hand-held power tool is a drill or a hammer drill.

13. The apparatus of claim 12 wherein the stator has an outside diameter of no more than 59 mm and a stack length of no more than 35 mm, and with a maximum no-load speed of 31,000 rpm, the motor provides at least 700 maximum watts out.

14. The apparatus of claim 1 wherein the hand-held power tool is a reciprocating saw.

15. The apparatus of claim 14 wherein the stator has an outside diameter of no more than 73 mm and a stack length of no more than 40 mm and with a maximum no-load speed of 24,500 rpm, the motor provides at least 1300 maximum watts out.

16. The apparatus of claim 1 wherein the hand-held power tool is an orbital sander or a random orbital sander.

17. The apparatus of claim 16 wherein the motor has a stack length of no more than 25 mm and is rated for an input amperage of at least three amps.

18. The apparatus of claim 17 wherein the sander has a height of no more than about 130 mm.

19. The apparatus of claim 16 wherein the stator has an outside diameter of no more than 55 mm.

20. The apparatus of claim 1 wherein the motor weighs at least five percent less than the needle wound motor having a stator with the same outside diameter and a 5 mm longer stack length.

21. The apparatus of claim 1 wherein the hand-held power tool is any of a router, a reciprocating saw, a power screw driver, or an impact wrench.

22. The apparatus of claim 1 wherein the field coils extend beyond pole tips of the pole pieces.

23. A hand-held power tool, comprising:

a housing in which an electric motor of a predetermined frame size is disposed, the motor including;

a stator having a lamination stack having pole pieces mated to return path pieces and field coils disposed on the pole pieces;

an armature disposed in the stator, the armature having an outside diameter that is at least 0.625 of an outside diameter of the stator;

a length of the lamination stack of the stator being the same length as a length of a lamination stack of a stator of a needle wound motor of the same frame size wherein the lamination stack of the stator of the needle wound motor includes a plurality of individual of laminations stacked together wherein each of the laminations includes slots in which magnet wires are wound to wind field coils; and

the motor having a maximum power output that is at least ten percent greater than a maximum power output of the needle wound motor of the same frame size with the same length lamination stack where both motors have the same maximum no load speed.

24. The apparatus of claim 23 wherein the stator has an outside diameter no greater than 59 mm and a lamination stack length no greater than 40 mm, and the motor with a maximum no-load speed of 31,000 rpm provides at least 800 maximum watts out.

25. The apparatus of claim 23 wherein the stator has an outside diameter no greater than 59 mm and a lamination stack length no greater than 40 mm, and the motor with a maximum no-load speed of 33,000 rpm provides at least 900 maximum watts out.

26. The apparatus of claim 23 wherein the stator has an outside diameter no greater than 59 mm and a lamination stack length no greater than 40 mm, and the motor with a maximum no-load speed of 35,000 rpm provides at least 1,000 maximum watts out.

27. The apparatus of claim 23 wherein the stator has an outside diameter no greater than 59 mm and a lamination stack length no greater than 40 mm, and the motor with a maximum no-load speed of 37,000 rpm provides at least 1,100 maximum watts out.

28. The apparatus of claim 23 wherein the stator has an outside diameter no greater than 59 mm and a lamination stack length no greater than 30 mm, and the motor with a maximum no-load speed of 31,000 rpm provides at least 600 maximum watts out.

29. The apparatus of claim 23 wherein the stator has an outside diameter no greater than 59 mm and a lamination stack length no greater than 35 mm, and the motor with a maximum no-load speed of 31,000 rpm provides at least 700 maximum watts out.

30. The apparatus of claim 23 wherein the stator has an outside diameter no greater than 59 mm and a lamination stack length no greater than 30 mm, and the motor with a maximum no-load speed of 32,000 rpm provides at least 650 maximum watts out.

31. The apparatus of claim 23 wherein the stator has an outside diameter no greater than 59 mm and a lamination stack length no greater than 35 mm, and the motor with a maximum no-load speed of 32,000 rpm provides at least 750 maximum watts out.

32. The apparatus of claim 23 wherein the stator has an outside diameter no greater than 59 mm and a lamination stack length no greater than 40 mm, and the motor with a maximum no-load speed of 32,000 rpm provides at least 850 maximum watts out.

33. The apparatus of claim 23 wherein the stator has an outside diameter no greater than 59 mm and a lamination stack length no greater than 35 mm, and the motor with a maximum no-load speed of 34,000 rpm provides at least 850 maximum watts out.

34. The apparatus of claim 23 wherein the stator has an outside diameter no greater than 59 mm and a lamination stack length no greater than 40 mm, and the motor with a maximum no-load speed of 34,000 rpm provides at least 950 maximum watts out.

35. The apparatus of claim 23 wherein the hand-held power tool is a drill or a hammer drill.

36. The apparatus of claim 23 wherein the field coils extend beyond pole tips of the pole pieces.