IP Library Granted Patent US 8,850,690
Granted Patent B2
US 8,850,690 · App. 13/666,304 · Granted Oct 7, 2014

Method of forming a power tool

Inventors: Hung T. Du (Reisterstown, MD); Brandon L. Verbrugge (Brookfield, WI); Joshua F. West (Towson, MD); Michael R. Sell (Bel Air, MD); Richard T. Walter (Baldwin, MD); David J. Smith (Columbia, MD); Earl M. Ortt (Towson, MD); John C. Stone (Cordova, MD); Howard T. White (Cedar Grove, TN)
Assignee: Black & Decker Inc.
H02K3/30H02K7/04H02K15/0056H02K15/02H02K15/165H02K3/48H02K15/12H01R43/10
View Patent ↗
Loading inventors, assignments & file history…
Monitor This Case
Get email alerts when status or documents change.
Order Certified Copies
Most orders are placed with the USPTO same day — all within 24 business hours.
Order via The Patent Place →
Pre-filled with this patent's details
Quick Facts
Patent No.
US 8,850,690
App. No.
13/666,304
Granted
Oct 7, 2014
Kind
B2
Abstract

A method of manufacturing an armature for an electric motor, includes: placing a commutator and a lamination stack on an armature shaft, winding magnet wire in slots in the lamination stacks to form coils, attaching ends of the magnet wire to the commutator, and molding plastic around the magnet wire and around the shaft of the armature at ends of the lamination stack. A spinning inertia of the armature is adjusted by adjusting at least one of a mass of the plastic molded and a distribution of the plastic molded. Alternatively and/or additionally, at least one of a resonant frequency and critical speed of the armature is adjusted by adjusting at least one of a geometry of the plastic molded, the physical properties of the plastic and the mechanical properties of the plastic.

Claims (9)

1. A method of manufacturing an armature for an electric motor, comprising:

placing a commutator and a lamination stack on an armature shaft;

winding magnet wire in slots in the lamination stacks to form coils;

attaching ends of the magnet wire to the commutator;

molding plastic around the magnet wire and around the shaft of the armature at ends of the lamination stack; and

adjusting a spinning inertia of the armature by adjusting at least one of a mass of the plastic molded and a distribution of the plastic molded.

2. The method of claim 1 , wherein the mass of plastic molded is adjusted by varying at least one of the density of the plastic molded and the amount of plastic molded.

3. The method of claim 1 , wherein adjusting the distribution of the plastic molded includes adjusting the mass of plastic placed at varying distances from an axis of rotation of the armature shaft.

4. The method of claim 1 , wherein the plastic is thermally conductive plastic.

Continuity (9)
Division 13472829 · May 16, 2012
Division 12895176 · Sep 30, 2010
Division 11491457 · Jul 21, 2006
Division 10616871 · Jul 10, 2003
Continuation In Part 10365065 · Feb 12, 2003
Division 09836517 · Apr 17, 2001
Continuation In Part 09756959 · Jan 9, 2001
Provisional Application 60395251 · Jul 12, 2002
Related Publication 20130291371A1 · Nov 7, 2013