Power tool with motor having a multi-piece stator

• US 8,558,420 B2
• Filed: 05/22/2012
• Issued: 10/15/2013
• 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., Hogan, Kevin M., Zhang, Jiaqi, Wang, Ren Hong, Mannarino, Frank A., Maid, Spencer G., Moll, Shane Ashley, Benton, James C.
• Primary Examiner(s): LE, DANG D
• Application Number:
  US13/477,858
• Publication Number:
  US 20120248902A1
• Time in Patent Office: 511 Days
• Field of Search: 310/89, 310/47, 310/50, 310/216.028
• US Class Current: 310/50
• 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 and field coils. The field coils are placed over necks of the pole path pieces. An armature has an outside diameter of at least 0.625 the outside diameter of the stator is placed in the stator. The housing has a girth of 200 mm or less with the motor wound to provide a maximum watts out to housing girth ratio of at least 5 maximum watts outs to 1 mm of housing girth. 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 is disposed; and

the electric motor including;

a stator having separately-formed pole pieces and field coils disposed around necks of the pole pieces, and an armature disposed in the stator and having an outside diameter (OD) that is at least 0.625 an outside diameter of the stator;

wherein the housing has a girth of 200 mm or less with the motor wound to provide a maximum watts out to housing girth ratio of at least 5 maximum watts outs to 1 mm of housing girth.

2. The apparatus of claim 1, wherein the power tool is a small angle grinder.

3. The apparatus of claim 1, wherein the stator has an OD no greater than 55 mm and a lamination stack having a length no greater than 48 mm, and the motor with a maximum no-load speed of 38,000 rpm provides at least 1000 maximum watts out.

4. The apparatus of claim 3 wherein the motor with a maximum no-load speed of 38,000 rpm provides at least 1200 maximum watts out.

5. The apparatus of claim 3 wherein the power tool is a small angle grinder.

6. The apparatus of claim 1 wherein the housing has height taken along a major axis of the housing of no more than 62 mm and a width taken along a minor axis of the housing of no more than 55 mm.

7. The apparatus of claim 6 wherein the power tool is a small angle grinder.

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