Why is the iron core of motors often made of stacked silicon steel sheets?
Iron core of motors often made of stacked silicon steel sheets
MATERIAL GUIDE
Non oriented silicon steel (NGO)sheet is currently the most cost-effective material for making motor iron cores. When mass producing motor iron cores, non oriented strip silicon steel sheets are usually laminated through continuous stamping film to produce the desired shape of the motor iron core. The use of stacked silicon steel sheets to produce motor iron cores is mainly aimed at reducing eddy current losses. Eddy current loss is the heat loss caused by the formation of a changing electric field in a conductor by a changing magnetic field, which in turn generates a surrounding current in the conductor. In an ideal situation, the larger the area of eddy current, the higher its loss, for example, the thicker the thickness of silicon steel sheet, the higher its eddy current loss. It should be noted that the stator core usually passes through alternating main magnetic flux and respective harmonics, so the stator core is usually made of stacked silicon steel sheets. However, the rotor core does not pass through alternating main magnetic flux, so a whole piece of low-carbon steel is also used as the core material for the rotor. For example, considering the cost and structural strength of the motor, the rotor core of the outer rotor is usually made of a whole piece of low-carbon steel.