Method for reducing arcing for motor armature with distributed windings

A method for controlling commutation of a two coil-per-slot electric motor, comprising:

• forming a stator having a plurality of spaced apart field coils defining a plurality of magnetic neutral zones;
• forming an armature having a plurality of radially extending posts defining a plurality of winding slots therebetween;
• segmenting a first coil into first and second subcoil portions;
• winding said first subcoil portion in a first pair of said slots;
• winding said second subcoil portion in a second pair of said slots that are offset by at least one slot position from said first pair of slots;
• said subcoil portions of said first coil defining a magnetic axis that is angularly shifted in a first direction from a center of said first coil;
• segmenting a second coil into first and second series coupled subcoil portions;
• winding said first subcoil portion of said second coil in a third pair of slots that are offset from said first pair of slots;
• winding said second subcoil portion of said second coil in a fourth pair of slots that are offset from said second pair of slots;
• said subcoil portions of said second coil defining a magnetic axis that is angularly shifted in a second direction from a center of said second coil that is opposite to that of said first direction;
• and
• electrically exciting said coils such that each begins and completes commutation at common angular points to define coincident, overlapping commutation regions.

A method of reducing at least one of brush arcing and electromagnetic interference in an electric motor, comprising:

• using a stator having a plurality of spaced apart field coils that define a plurality of commutation zones therebetween;
• disposing an armature coaxially relative to said stator;
• segmenting a first coil into first and second series coupled coil portions that are wound on said armature in first and second offset slot pairs of said armature such that a magnetic axis of said first coil is angularly offset in a first direction, relative to a center of said first coil;
• segmenting a second coil into first and second series coupled coil portions that are wound in third and fourth slot pairs of said armature that are offset by at least one slot position from said first and second slot pairs, respectively, such that a magnetic axis of said second coil is angularly offset in a second direction, relative to a center of said second coil, wherein said second direction is opposite to said first direction;
• and
• electrically exciting said first and second coils, each of said first and second coils such that each commutates within coincident, overlapping commutation zones.