Silicon steel coil is a key component of electric motors and appliances. Its performance is not only directly related to the loss of electric energy, but also related to the performance, volume and weight of the motor, transformer and other products. Therefore, the performance of silicon steel coil has the following requirements: (1) it has good shape and surface coating, high dimensional accuracy, and small thickness difference; (2) It has good electromagnetic properties and grain orientation structure, meet the application requirements.
The blanking process of silicon steel coil should not only have the general metal shearing process and product characteristics, but also meet the following special requirements.
Burr height
The burr height of silicon steel coil is not greater than 0.05mm. More and more attention has been paid to the effect of burr on the performance of machine parts. The burr on the silicon steel coil for generators, motors and transformers has an important effect on its electromagnetic characteristics. Silicon steel coils for generators, motors and transformers are formed by die cutting. Usually, the mold manufacturing clearance is too large, or the clearance increases due to wear. During the unloading process, the silicon steel coil is squeezed, resulting in a slight plastic deformation that remains on the edge of the silicon steel coil and forms burrs. The rotor, stator, and transformer cores of generators and motors are made of a large number of stamped silicon steel coils. The burr on the silicon steel coil reduces the stacking factor. If the same number of plates are to be installed, the volume of the motor must increase. In addition, burrs also affect the output power of the motor. The practice shows that the output power of the generator after the deburring of the silicon steel coil is 0.1% ~ 0.2% higher than that without the deburring of the silicon steel coil.
The generator life is affected
The existence of silicon steel coil burr leads to too large gap between the sheets, which is easy to generate eddy current, increase magnetic loss, increase temperature rise and noise, and even short circuit, leading to motor failure. Compared with non-deburring silicon steel coil, the average service life of the motor after deburring can be increased by more than 5%.
The processed silicon steel coil can generally be stacked automatically or manually, and the gap at the seam should be as small as possible. This requires high accuracy (including accuracy of parts) for the equipment at maximum capacity so that the shear product is generally burr free (the height of burr for silicon steel rolls after shear is no greater than 0.05mm). Otherwise, burrs will short-circuit the lap between the sheets during the stacking process, increase eddy current loss and reduce the filling coefficient of the sheets.
Post time: Mar-24-2023