DC motor with dual commutator bar set and selectable series and parallel connected coils
US7893586B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 20, 2007 |
| Grant date | Feb 22, 2011 |
| Priority date | — |
| Expiry date | Jul 2, 2027 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02K23/04
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A permanent magnet, DC motor especially well adapted for use in power tools, and particularly hand-held, battery powered power tools. The motor includes two sets of armature coils, with each set of coils being coupled to separate sets of commutator bars on an armature. Separate pairs of brushes are used to interface with the two sets of commutator bars. A switching subsystem is controlled either manually by a user engageable switch or automatically by a controller, to connect the two sets of coils in either series or parallel configurations. The series configuration provides a greater efficiency, but with a lower power output than the parallel connection. The parallel connection provides a greater maximum power output from the motor. Thus, the operating characteristics of the tool can be tailored to better meet the needs of a work task, and in a manner than makes most efficient use of available battery power.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.