The greater the capacity of the transformer now used, the greater the impact on the power grid, requiring more and more safety. Transformer manufacturing quality performance, not only requires reliable electrical performance, mechanical stability, anti-short circuit capability should also be more reliable. Mainly in the stability of the coil manufacturing process control, which requires high voltage coil electromagnetic balance, axial turn tight, evenly distributed. Therefore, it is required that the winding process of the coil be compressed in the axial direction and be wound tightly in the radial direction. The vertical winding machine just takes advantage of the weight of the wire cake and the natural axial compression, and the tensioning device controls the tension in the radial direction. So now large-scale transformers in the high-voltage coil winding system commonly used vertical winding machine, even the low-voltage spiral coil also uses a vertical winding machine production.
Vertical winding machine now further to the large-scale development. The original vertical winding machine load only 20t, has now been increased to 40t, the largest coil diameter to 3500mm, the maximum height to 4000mm. The use of airbag plate tensioning device, and the figures show the size of tension, tension control more accurate, stable and reliable. In order to improve the dimensional accuracy of the coil, control the radial runout of the vertical winding machine, an increase of winding mold shaft head fixing device; in order to control the axial runout, the use of high-precision double-row roller large bearings. Therefore, by using coil winding special equipment, winding production reached a new level. So that the transformer to further reduce losses, reduce PD, reduce weight and reduce costs possible.