A D.C. machine consists of two main parts:
(i) Stationary part. It is designed mainly for producing a magnetic flux.
(ii) Rotating part. It is called the armature, where mechanical energy is converted into electrical (electrical generator), or conversely, electrical energy into mechanical (electric motor).
The stationary and rotating parts are separated from each other by an air gap.
- The stationary part of a D.C. machine consists of main poles, designed to create the magnetic flux, commutating poles interposed between the main poles and designed to ensure sparkless operation of the brushes at the commutator (in very small machines with a lack of space com mutating poles are not used) ; and a frame/yoke,
Fig. 1. Generator or motor magnetic structure.
- The armature is a cylindrical body rotating in the space between the poles and comprising a slotted armature core, a winding inserted in the armature core slots, a commutator, and brush gear.
Fig.1 shows generator or motor magnetic structure,
Description of Parts of D.C. Machines: