The motor core uses silicon steel sheet（硅钢片）, which was previously called silicon steel sheet（矽钢片）. This material has good magnetic permeability and poor electrical conductivity.
The motor generates magnetic force through the coil windings and operates using this magnetic force. However, because an alternating magnetic field generates a current in the core,
If the iron core has strong electrical conductivity, it is equivalent to a closed short circuit and generates heat, which is called eddy current.
The principle is the same as that of the induction cooker heating the bottom of the pot through the electromagnetic field. Therefore, in order to cut off such eddy currents, it is also reasonable to use silicon steel materials with poor electrical conductivity and to adopt silicon steel sheets one by one without using a solid core.
In the past, silicon steel sheets were lacking, and iron varnishes were used to solve this problem.