Method and manufacturing an electric coil assembly
Instead of being made from one continuous piece of material, a coil includes multiple flat coil segments that are stacked together and electrically coupled in series. In many embodiments, the coil segments are U-shaped segments, and the segments are arranged so that each segment is rotated (e.g., by 270 degrees) with respect the segment it follows. The stacked coils may then be fastened together using, for example, bolts through the corners of the coil segments. The combined coil segments form a continuous coil.
1. A method of manufacturing an electric coil assembly, said method comprising:
obtaining a plurality of electrically conducting coil segments, each coil segment completing less than a full loop, wherein each coil segment of the plurality of coil segments has a first hole located at a first end and a second hole located at a second end;
stacking the plurality of electrically conducting coil segments together to form multiple loops of an electric coil in which the plurality of electrically conducting coil segments are electrically connected together end-to-end and in series, wherein, for each coil segment among the series connected electrically conducting coil segments in the multi-loop electric coil that is connected to a next coil segment among the series connected plurality of electrically conducting coil segments, the second end of said coil segment is connected to the first end of the next coil segment with the second hole of the second end of said coil segment aligned with the first hole of the first end of the next coil segment to form an aligned hole pair, and wherein the aligned hole pairs of the plurality of series connected electrically conducting coil segments are arranged and coaxially aligned to form a plurality of passageways and wherein each selected passageway of the plurality of passageways is formed by a different plurality of the aligned hole pairs of the series connected coil segments along the selected passageway; and
holding the stacked coil segments together with a plurality of fasteners extending through the plurality of passageways to form the electric coil assembly in which the plurality of coil segments remain electrically connected together in series.
2. A method as in claim 1 wherein obtaining the plurality of electrically conducting coil segments involves fabricating the plurality of electrically conducting coil segments.
3. A method as in claim 2 wherein (i) fabricating the plurality of electrically conducting coil segments includes fabricating multiple U-shaped coil segments and (ii) stacking includes rotating each U-shaped coil segment 270 degrees with respect to the U-shaped coil segment that it follows.
4. A method as in claim 2 further including coating portions of each of the coil segments with an electrically-insulating material.
5. A method as in claim 2 further including inserting electrically-insulating spacers in gaps between the stacked coil segments.
6. A method as in claim 2 wherein fabricating the plurality of coil segments includes stamping the plurality of coil segments from one or more flat sheets of metal.
7. A method as in claim 2 wherein fabricating the plurality of coil segments includes etching the plurality of coil segments from one or more flat sheets of metal.
8. A method as in claim 1 , wherein the electric coil formed by the plurality of conducting coil segments electrically connected together in series has at least three complete windings.
9. A method as in claim 8 , wherein the electric coil formed by the plurality of conducting coil segments electrically connected together in series has greater than three complete windings.
10. A method as in claim 1 , wherein stacking the plurality coil segments together forms an electric coil characterized by a plurality of complete winding loops, wherein the plurality of complete winding loops is less in number than the plurality of coil segments.