armature windings

Understanding Mature Windings in Electrical Engineering

Introduction to Coils and Conductors

• A coil is defined as the loop starting from commutator segment 1 and ending at commutator segment 2, represented by PQRES in the schematic diagram.

• Each coil consists of two sides or conductors: PQ (one side) and RES (the other side). In a single turn coil, each side is equivalent to a conductor.

• A single turn coil can have multiple turns, with connections made to commutator segments at points 1 and 2.

Multi-Turn Coils

• The schematic for multi-turn coils shows that each coil side comprises multiple conductors; specifically, three conductors per side are tied together as a unit.

• These groups of conductors are housed within armature slots designed for this purpose.

Key Definitions Related to Pitch

Pole Pitch

• Pole pitch is the distance between two adjacent poles, measured in terms of slots or coil sides; it can be calculated as the ratio of stator slots to poles. For example, with 24 armature slots and 4 poles, pole pitch (Pp) equals 6.

Coil Pitch

• Coil pitch (Pc) measures the distance between two sides of a coil in terms of armature conductors; it is determined by the difference between specific coil sides (e.g., sides 1 and 5 yield Pc = 4).

Back Pitch & Front Pitch

• Back pitch (Pb) refers to the distance between two sides of a coil at the back end of an armature; for instance, Pb equals 7 when comparing sides 8 and 1.

• Front pitch (Pf) measures distance at the front end connected to commutators; Pf equals 5 when comparing sides 3 and 8.

Resultant Pitch

• Resultant pitch (Pr) indicates the distance from one coil's beginning to another's beginning; Pr equals 2 when measuring from sides 1 to 3.

Types of Windings

Single Layer Winding

• In single layer windings, the number of coil sides is half that of available slots according to its schematic representation.

Two Layer Winding

• Conversely, in two-layer windings, there are equal numbers of coils and slots depicted in its schematic diagram.

Lap vs Wave Windings

Wave Winding

• Wave winding features arrangements where two conductors do not lie under the same pole; for example, conductor PQ lies under a north pole while RR lies under a south pole. This configuration allows for parallel parts relative to pole count but typically requires only two sets of brushes regardless of total poles present.

Lap Winding