Abstract: Hollow cylindrical dynamo-electric machine stator cores may be made by superimposing at least two strips of core material to produce a composite strip. One or more of the strips may be run through a pressure roller structure prior to super-positioning of the strips. The composite strip is coiled helically to produce the hollow cylindrical stator core. By pressure rolling at least one strip, the internal diameter of the stator core can be adjusted to reduce irregularities. By superimposing strips prior to coiling, thinner strips can be used without requiring the stator forming machine to operate longer or faster to produce stator cores of a given size. The pressure rolling aspects of the invention are also applicable to coiling apparatus that uses only a single strip. Stator cores may also be made by coaxially assembling and joining two coils with a hollow annular lamination disposed between the two axially spaced coils.

Abstract: Hollow cylindrical dynamo-electric machine stator cores may be made by superimposing at least two strips of core material to produce a composite strip. One or more of the strips may be run through a pressure roller structure prior to super-positioning of the strips. The composite strip is coiled helically to produce the hollow cylindrical stator core. By pressure rolling at least one strip, the internal diameter of the stator core can be adjusted to reduce irregularities. By superimposing strips prior to coiling, thinner strips can be used without requiring the stator forming machine to operate longer or faster to produce stator cores of a given size. The pressure rolling aspects of the invention are also applicable to coiling apparatus that uses only a single strip. Stator cores may also be made by coaxially assembling and joining two coils with a hollow annular lamination disposed between the two axially spaced coils.

Abstract: Hollow cylindrical dynamo-electric machine stator cores may be made by superimposing at least two strips of core material to produce a composite strip. One or more of the strips may be run through a pressure roller structure prior to super-positioning of the strips. The one or more strips may contain internal apertures. The composite strip is coiled helically to produce the hollow cylindrical stator core. By pressure rolling at least one strip, the internal diameter of the stator core can be adjusted to reduce irregularities. By superimposing strips prior to coiling, thinner strips can be used without requiring the stator forming machine to operate longer or faster to produce stator cores of a given size, even though thinner strip material is being used. By using strips that contain internal apertures, unwanted deformations can be reduced. The pressure rolling aspects of the invention and the strips that may contain internal apertures are also applicable to coiling apparatus that uses only a single strip.