Single layer coil
The single-layer coil is wound around the paper tube or bakelite skeleton in a circle with insulated wires. Such as a transistor radio wave antenna coil.
A single-layer winding is a winding in which only one active side of the coil is embedded in each stator slot, so that the total number of coils is only half of the total number of slots of the motor. The advantage of the single-layer winding is that the number of winding coils is relatively simple; the utilization of the interlayer insulation is not improved; the single-layer structure does not cause phase-to-phase breakdown failure. The disadvantage is that the electromagnetic waveform generated by the winding is not ideal, the iron loss and noise of the motor are large and the starting performance is also slightly poor, so the single-layer winding is generally only used in the small-capacity asynchronous motor.
If the coil is wound, its plane is not parallel to the plane of rotation, but intersects at an angle. This type of coil is called a honeycomb coil. And the number of times the wire is bent back and forth, often referred to as the number of vertices. The advantage of the honeycomb type winding method is that the volume is small, the distributed capacitance is small, and the inductance is large. The honeycomb coils are wound by a honeycomb winding machine. The more the folding points, the smaller the distributed capacitance.
The honeycomb type coil has small volume, small submersible capacity, large inductance, and high Q value, so many tuning coils, oscillating coils and high-frequency chokes of the radio are wound in this way. Other ways are good. In the factory, such coils are usually wound with a hive.