Lap Winding
Table of Contents
Lap Winding, Simplex Winding, Duplex and Triplex Winding
The most crucial element of the Rotating machine is the armature winding. It is the place where energy Conversion takes place,. I.e., the Mechanical energy is Converted into Electrical energy, and the Electrical energy is converted into Mechanical energy. The Armature winding is mainly Classified into two types, i.e., the lap winding and the wave winding.
Lap Winding
In lap winding, the conductors are connected so that the number of their parallel paths and poles is the same on each conductor. Each armature coil’s end is attached to its neighbouring commutator segment. In the lap-windings, there are exactly as many brushes as parallel paths,. And they are equally split between brushes with negative and positive polarity. Most machine applications for low voltage, high current use lap winding. DC generators intended for high-current applications use this kind of winding. The connections between the windings create a number of parallel paths for current in the armature. Lap-wound armatures used in dc generators need numerous pairs of poles and brushes because of this.
In lap-windings, the starting end of one coil is connected to a commutator segment, the finishing end of the subsequent coil is connected to the starting end of the subsequent coil located under the same pole, and so on, until all the coils have been connected. The fact that this type of winding doubles or laps back with succeeding coils is where it gets its name.
Three different categories classified
- Simplex Lap Winding
- Duplex Lap Winding
- Triplex Lap Winding
1. Simplex Lap Winding:
In simplex lap winding, the starting end of one coil is positioned under the same pole as the terminating end of the previous coil, which is connected to the commutator segment. Additionally, the number of parallel paths and the number of poles in the windings are comparable.
Following points regarding simplex winding should noted:
1. The back and front pitches are odd and of opposite sign.But they can’t be equal. They differ by 2 or some multiple thereof.
2. Both YB and YF shpuld be nearly equal to a pole pitch.
3. The average pitch YA = (YB + YF)/2.It equals pole pitch = Z/P.
4. Commutator pitch YC = ±1.
5. Resultant pitch YR is even, being the arithmetical difference of two odd numbers i.e YR = YB – YF.
6. The number of slots for a 2-layer winding is equal to the number of coils.The number of commutator segments is also the same.
7. The number of parallel paths in the armature = mP where ‘m’ is the multiplicity of the winding and ‘P’ the number of poles.Taking the first condition, we have YB = YF ± 2m where m=1 fo simplex lap and m =2 for duplex winding etc.
8. If YB > YF i.e YB = YF + 2, then we get a progressive or right-handed winding i.e a winding which progresses in the clockwise direction as seen from the comutator end.In this case YC = +1.
9. If YB < size=”1″>F i.e YB = YF – 2,then we get a retrogressive or left-handed winding i.e one which advances in the anti-clockwise direction when seen from the commutator side.In this case YC = -1.
10. Hence, it is obvious that for
2. Duplex Winding:
In duplex Lap winding, there are twice as many parallel paths between poles as there are poles. Heavy current applications are where duplex lap windings are most frequently use. Such a winding is create by mounting two identical windings on the same armature and connecting the even-numbered and odd-numbered commutator bars to the respective windings.
3. Triplex Lap Winding:
The third of the commutator bars are connect to the windings in a triplex winding. The lap-windings is use for applications requiring higher currents because it has numerous paths. The lap-windings only drawback is that it uses a lot of conductors, which drives up the cost of the winding.