Slotless rotating electric machine
A slotless rotating electric machine includes a rotor having multiple alternating polarity permanent magnets that drive magnetic flux across a magnetic airgap formed with a slotless ferromagnetic stator. The stator includes a helical backiron formed from a ferromagnetic strip wound edgewise and extending axially, and an adhesive film on the radial airgap surface of the backiron. Armature windings of wire having individually insulated twisted strands diametrically enveloped by an outer serve are adhered to the adhesive film. The adhesive film holds the said serve to the backiron and the serve holds the strands to the adhesive film. The armature windings pressed into the adhesive film as a group after they are formed and adhered while the adhesive cures, such that the wire is both bonded to the radial airgap surface of the helical stator backiron and is additionally partially embedded in the adhesive film.
1. A slotless rotating electric machine comprising:
a rotor having multiple alternating polarity permanent magnets that drive magnetic flux back and forth across a magnetic airgap formed with a radial airgap surface of a slotless ferromagnetic stator;
said slotless ferromagnetic stator comprising a helical stator backiron formed from a ferromagnetic strip wound edgewise and extending axially and an adhesive film on said radial airgap surface of said helical stator backiron;
armature windings of wire adhered to said adhesive film on said radial airgap surface wherein said wire comprises individually insulated twisted strands diametrically enveloped by an outer serve;
said adhesive film holding said serve to said helical stator backiron with said serve holding said strands to said adhesive film;
said armature windings comprising an air core winding pattern formed directly onto said adhesive film in a one wire radial layer that is only one wire deep where inside said magnetic airgap, and having end turns of multiple phases overlapping,
said armature windings pressed into said adhesive film as a group after formed and adhered while said adhesive film cures, such that said wire is both bonded to said radial airgap surface of said helical stator backiron and is additionally partially embedded in said adhesive film.
2. The slotless rotating electric machine as described in claim 1 wherein: said slotless ferromagnetic stator is adapted to hold said armature windings in said air core winding pattern onto said helical stator backiron by adhesion to said adhesive film in B-stage condition when said air core winding pattern is formed, by applied radial pressure to said armature windings against said helical stator backiron while during transition of said adhesive film from said B-stage condition to C-stage condition, and by adhesion to said adhesive film in said C-stage condition in operation of said slotless rotating electric machine.
3. The slotless rotating electric machine as described in claim 1 wherein: said adhesive film is flowed partially up sides of said wire in a direction away from said helical stator backiron and towards said rotor where located inside said magnetic airgap.
4. The slotless rotating electric machine as described in claim 1 wherein: said adhesive film comprises an internal carrier that maintains a minimum dielectric strength between said wires and said helical stator backiron where located in said magnetic airgap.
5. The slotless rotating electric machine as described in claim 1 wherein: said carrier comprises a fabric.
6. The slotless rotating electric machine as described in claim 1 wherein: each said wire in said magnetic airgap is in direct heat conduction to said adhesive film and said adhesive film is in direct heat conduction to said helical stator backiron.
7. The slotless rotating electric machine as described in claim 1 wherein: said strands of said wire are widely unimpregnated in locations inside said magnetic airgap.
8. The slotless rotating electric machine comprising: a rotor having multiple alternating polarity permanent magnets that drive magnetic flux back and forth across a magnetic airgap formed with an airgap surface of a slotless ferromagnetic stator;
said slotless ferromagnetic stator comprising a stator backiron ring formed from ferromagnetic material and an adhesive film on said airgap surface of said stator backiron ring;
armature windings of wire adhered to said adhesive film on said airgap surface wherein said wire comprises individually insulated twisted strands;
said armature windings comprising an air core winding pattern formed directly onto said adhesive film;
said armature windings pressured against said stator backiron ring as a group after formed and adhered with heat, imparting said armature windings to be secured in said air core winding pattern formed on said airgap surface, and additionally with said adhesive film flowed partially up a sides of said wire in a direction away from said stator backiron ring and towards said rotor at locations inside said magnetic airgap;
said adhesive film providing increased resistance to force on said armature windings.
9. The slotless rotating electric machine as described in claim 8 wherein: said slotless ferromagnetic stator is adapted to hold said armature windings in said air core winding pattern onto said stator backiron ring by adhesion to said adhesive film in B-stage condition when said air core winding pattern is formed, by applied pressure to said armature windings against said stator backiron while during transition of said adhesive film from said B-stage condition to C-stage condition, and by adhesion to said adhesive film in said C-stage condition in operation of said slotless rotating electric machine.
10. The slotless rotating electric machine as described in claim 8 wherein: said pressure is applied prior to said adhesive film reaching the maximum curing temperature during said transition to said C-stage condition.
11. The slotless rotating electric machine as described in claim 8 wherein: said armature windings are unencapsulated by molded adhesive at locations inside said magnetic airgap.
12. The slotless rotating electric machine as described in claim 8 wherein: said stator backiron ring is formed of a ferromagnetic strip wound edgewise and extending axially in a helix wherein said adhesive film is applied to said radial airgap surface comprising the edges of said strip.
13. The slotless rotating electric machine as described in claim 8 wherein:
said wire comprises a serve of dielectric material helically wrapped around said strands wherein said adhesive film holds said wire to said stator backiron ring and said serve holds said strands to said adhesive film.
14. The slotless rotating electric machine as described in claim 8 wherein: said adhesive film comprises an internal carrier that maintains a minimum dielectric strength between said wires and said stator backiron ring where located in said magnetic airgap after said adhesive film is cured to said C-stage condition.
15. A slotless rotating electric machine comprising: a rotor having multiple poles that drive magnetic flux across a magnetic airgap formed with a radial airgap surface of a slotless ferromagnetic stator;
a slotless ferromagnetic stator formed as a helical stator backiron of a ferromagnetic strip wound edgewise and extending axially;
an adhesive film on said radial airgap surface of said helical stator backiron;
armature windings of wire adhered to said adhesive film on said radial airgap surface wherein said wire comprises individually insulated twisted strands diametrically enveloped by an outer serve;
said adhesive film holding said serve to said helical stator backiron with said serve holding said strands to said adhesive film;
said armature windings applied in an air core winding pattern onto said adhesive film in a one wire radial layer that is only one wire deep where inside said magnetic airgap, and with end turns of multiple phases overlapping;
said air core winding pattern secured to said helical stator backiron on said radial airgap surface and additionally by said adhesive film flowed partially up the sides of said wire in a direction away from said helical stator backiron and towards said rotor at locations inside said magnetic airgap, not including the side of said wire facing the rotor opposite said radial airgap surface of said helical stator backiron;
said flowed adhesive imparting increased resistance to force on said armature windings.
16. The slotless rotating electric machine as described in claim 15 wherein:
said adhesive film is adapted to hold said armature windings in said air core winding pattern while in B-stage condition, and said helical stator backiron is adapted to maintain said winding pattern through applied radial pressure to said armature windings against said helical stator backiron during transition of said adhesive film from said B-stage condition to C-stage condition.
17. The slotless rotating electric machine as described in claim 15 wherein: said adhesive film comprises an internal carrier that maintains a minimum dielectric strength between said wires and said helical stator backiron where located in said magnetic airgap.
18. The slotless rotating electric machine as described in claim 17 wherein: said carrier comprises a fabric.
19. The slotless rotating electric machine as described in claim 15 wherein: said wire comprises a porous bundle of strands at locations outside said magnetic airgap.
20. The slotless rotating electric machine as described in claim 15 wherein: said adhesive film flow partially up the sides of said wire and cured to said serve holds said wire in a compressed state from round, imparting a reduced radial thickness of said armature windings inside said magnetic airgap.