Stator winding


Impregnation technology

Stator winding

I-pin, hairpin, round wire winding

There are two main methods for coil winding: concentrated and distributed winding. For concentrated winding, each coil is wound on its own pole face, whilst in distributed winding, each coil is spread over several pole faces. Quadratic wires can be used to fill the valuable slot area better and increase efficiency.

bdtronic has many years of experience with different winding technologies, whether needle, flyer, single pole, hairpin or insert winding. All stator winding types can be processed with our modern impregnation equipment.

Stator winding technologies overview:

  • Bar/flat wire (hairpin, I-pin, wave/S-winding).
  • Round wire (insertion/distribution winding)
  • Concentrated (pole/section winding)
  • Special applications

I-Pin stators can be impregnated efficiently and cleanly by using the trickle process.

Hairpin / I-Pin winding

The name of hairpin stators derives from the shape of the winding wires. First, rectangular‐wire bars are bent into a hairpin shape. They are then inserted into the slots of the stator in the axial direction. After that, the ends of the hairpin coils are bent. For the hairpin winding construction technique, half-turns of wire are preformed into a hairpin-like shape to lie precisely in the slots, then welded together to form complete turns. Finally, the ends of the hairpin coils are welded so that the connected coils form a wave shape. Whenstraightbars(i-pin)areused, the stator is called I-Pin. The welding tips of these stators must be coated. bdtronic offers powder coating technology for this purpose.

Round wire winding

First, round wire coils are wound outside the stator core. After that, coils are inserted into the stator slots from the inner side of the core. The coils thus overlap in the radial direction. Finally, these overlapped coil ends are formed in the axial and radial directions to be housed in the motor case.

Contact our sales team for more information. Take advantage of our many years of experience and know-how in the impregnation of electric motors.
Sales worldwide