Axial flux electric machine pole piece with conductive ribbons

An axial flux electric machine comprising:

• a stator having a plurality of pole pieces;
• a rotor spaced apart from the stator in an axial direction of the axial flux electric machine;
• a coiled ribbon of conductive material forming at least part of a pole piece in the plurality of pole pieces;
• a second coiled ribbon of conductive material forming at least part of the pole piece;
• a gap between the second coiled ribbon of conductive material and the coiled ribbon of conductive material in the axial direction of the axial flux electric machine;
• and
• a coiled ribbon of soft magnetic material forming at least part of the pole piece;
• wherein an axial direction of the coiled ribbon of conductive material is substantially parallel to the axial direction of the axial flux electric machine;
• wherein the coiled ribbon of soft magnetic material and the coiled ribbon of conductive material are commonly coiled in an interleaved composite material coil;
• wherein the coiled ribbon of conductive material is at least partially sheathed in insulating material such that the coiled ribbon of conductive material comprises a conductive core that is insulated from ohmic contact in the interleaved composite material coil;
• and
• wherein:
• (i) the coiled ribbon of conductive material is coiled in a first direction;
• (ii) the second coiled ribbon of conductive material is coiled in the first direction;
• and (iii) the second coiled ribbon of conductive material and the coiled ribbon of conductive material are adjacent in the axial direction of the axial flux electric machine.

An axial flux electric machine comprising:

• a stator having a plurality of pole pieces;
• a rotor spaced apart from the stator in an axial direction of the axial flux electric machine;
• a coiled ribbon of conductive material forming at least part of a pole piece in the plurality of pole pieces;
• a coiled ribbon of soft magnetic material forming at least part of the pole piece;
• and
• a second coiled ribbon of conductive material forming at least part of the pole piece;
• wherein:
• (i) the coiled ribbon of conductive material and the second coiled ribbon of conductive material are part of a single continuous strip of conductive material;
• and (ii) the second coiled ribbon of conductive material and the coiled ribbon of conductive material are adjacent in the axial direction of the axial flux electric machine;
• wherein an axial direction of the coiled ribbon of conductive material is substantially parallel to the axial direction of the axial flux electric machine;
• wherein the coiled ribbon of soft magnetic material and the coiled ribbon of conductive material are commonly coiled in an interleaved composite material coil;
• wherein the coiled ribbon of conductive material is at least partially sheathed in insulating material such that the coiled ribbon of conductive material comprises a conductive core that is insulated from ohmic contact in the interleaved composite material coil;
• and
• wherein:
• (i) the coiled ribbon of conductive material presents a first external electrical contact for the pole piece on an outermost turn of the coiled ribbon;
• (ii) the second coiled ribbon of conductive material presents a second external electrical contact for the pole piece on an outermost turn of the second coiled ribbon;
• (iii) the first external electrical contact is ohmically coupled to the second external electrical contact through the coiled ribbon and the second coiled ribbon via a conductive path;
• and (iv) the conductive path includes a pair of symmetrical folds in the single continuous strip of conductive material that links the coiled ribbon of conductive material and the second coiled ribbon of conductive material.