commutator position determination
In medium and large DC motors, when determining the extension of the armature winding end or the position of the commutator, the axial extension of the compensation winding should also be considered. Since the ends of the compensation windings tend to be very long, the determined commutator position will not be suitable unless the axial dimension of the rotor is correspondingly lengthened.
When selecting the diameter of the commutator, it is generally always as small as possible. This is more economical, and the friction loss of the brush is also small. However, when the diameter is small, the width of the commutator and the width of the brush will decrease when the ratio of the width of the brush to the width of the sheet is constant. If the diameter is too small, the strength will not be enough. The parts of the commutator should generally be mechanically calculated.
In the case of end cap bearings, the commutator sleeve lumen should have a sufficient size of air passage for ventilation. In large motors with seat bearings, in order to facilitate the maintenance of the brush device, the motor should be sunk in the foundation.
