Bridgeless and webless rotor assembly using polymer composites

1. A rotor assembly for a permanent magnet motor, comprising:

a first assembly including a first plurality of laminations;

a second assembly including a second plurality of laminations,

wherein the first assembly is located radially inside of the second assembly and wherein the first assembly and the second assembly define a first opening therebetween;

first and second permanent magnets located in the first opening;

polymeric material surrounding the first and second permanent magnets in the first opening;

an outer layer surrounding the rotor assembly;

a third assembly including a third plurality of laminations, wherein the second assembly and the third assembly define a second opening therebetween; and

third and fourth permanent magnets located in the second opening,

wherein the polymeric material surrounds the third and fourth permanent magnets located in the second opening,

wherein the first assembly includes a first sub-assembly including first ones of the first plurality of laminations and a second sub-assembly including second ones of the first plurality of laminations,

wherein the first sub-assembly and the second sub-assembly define a facing side surfaces including circumferential segments and other segments and wherein the circumferential segments define a larger gap than the other segments, and

wherein the facing side surfaces of the first sub-assembly and the second sub-assembly define a stair-step pattern.

2. The rotor assembly of claim 1 , wherein the rotor assembly does not include webs and wherein the rotor assembly does not include bridges and wherein the outer layer is made of carbon fiber.

3. The rotor assembly of claim 1 , wherein the first opening is “V” shaped and extends to the outer layer.

4. The rotor assembly of claim 1 , wherein the polymeric material includes resin.

5. The rotor assembly of claim 4 , wherein the resin is selected from a group consisting of epoxy, polyurethane, polyester, bismaleimide, acrylic, cyanate ester, polyimide, phenolic, benzoxazine, and vinyl ester.

6. The rotor assembly of claim 4 , wherein the resin further includes a discontinuous fill material.

7. The rotor assembly of claim 6 , wherein the discontinuous fill material includes one or more materials selected from a group consisting of silica, alumina, minerals, boron nitride, aluminum nitride, silicon nitride, basalt, and glass fibers.

8. The rotor assembly of claim 1 , wherein the first sub-assembly and the second sub-assembly include facing side surfaces including a circumferential segment and a diagonal segment and wherein the circumferential segment defines a larger gap than the diagonal segment.

9. The rotor assembly of claim 1 , wherein the first sub-assembly and the second sub-assembly include facing side surfaces including a circumferential segment, a diagonal segment, and a retention segment, and wherein the circumferential segment defines a larger gap than the diagonal segment.

10. The rotor assembly of claim 1 , wherein at least one of the first sub-assembly and the second sub-assembly defines a female opening and the other one of the first sub-assembly and the second sub-assembly defines a male projection that is received within the female opening.

11. The rotor assembly of claim 10 , wherein the male projection is “T”-shaped and includes first and second arms and further comprising first and second gaps defined between the first and second arms and the female opening and wherein the polymeric material is located in the first and second gaps.

12. A rotor assembly for a permanent magnet motor, comprising:

a first assembly including a first plurality of laminations;

a second assembly including a second plurality of laminations, wherein the first assembly and the second assembly define a first opening therebetween;

a third assembly including a third plurality of laminations, wherein the second assembly and the third assembly define a flux barrier therebetween;

first and second permanent magnets located in the first opening;

polymeric material surrounding the first and second permanent magnets in the first opening; and

a carbon fiber outer layer surrounding the rotor assembly,

wherein the rotor assembly does not include webs and wherein the rotor assembly does not include bridges,

wherein the second assembly and the third assembly further define a second opening therebetween; and

third and fourth permanent magnets located in the second opening,

wherein the polymeric material further surrounds the third and fourth permanent magnets located in the second opening,

wherein the first assembly includes a first sub-assembly including first ones of the first plurality of laminations and a second sub-assembly including second ones of the first plurality of laminations,

wherein the first sub-assembly and the second sub-assembly define a facing side surfaces including circumferential segments and other segments and wherein the circumferential segments define a larger gap than the other segments, and

wherein the facing side surfaces of the first sub-assembly and the second sub-assembly define a stair-step pattern.

13. The rotor assembly of claim 12 , wherein the flux barrier includes polymeric material mixed with magnetic particles.

14. The rotor assembly of claim 13 , further comprising:

a fourth assembly including a fourth plurality of laminations; and

third and fourth permanent magnets located in a second opening,

wherein the polymeric material surrounds the third and fourth permanent magnets located in the second opening and wherein the third assembly and the fourth assembly define a second opening therebetween.

15. The rotor assembly of claim 13 , wherein the first opening, the flux barrier and the second opening are “V” shaped and extend to the carbon fiber outer layer.

16. The rotor assembly of claim 12 , wherein the polymeric material includes epoxy resin and a discontinuous fill material include one or more materials selected from a group consisting of silica, alumina, minerals, boron nitride, aluminum nitride, silicon nitride, basalt, and glass fibers.

17. A rotor assembly for a permanent magnet motor, comprising:

a first assembly including a first plurality of laminations;

a second assembly including a second plurality of laminations,

wherein the first assembly is located radially inside of the second assembly and wherein the first assembly and the second assembly define a first opening therebetween;

first and second permanent magnets located in the first opening;

polymeric material surrounding the first and second permanent magnets in the first opening;

an outer layer surrounding the rotor assembly;

a third assembly including a third plurality of laminations, wherein the second assembly and the third assembly define a second opening therebetween; and

third and fourth permanent magnets located in the second opening,

wherein the polymeric material surrounds the third and fourth permanent magnets located in the second opening,

wherein the first assembly includes a first sub-assembly including first ones of the first plurality of laminations and a second sub-assembly including second ones of the first plurality of laminations,

wherein at least one of the first sub-assembly and the second sub-assembly defines a female opening and the other one of the first sub-assembly and the second sub-assembly defines a male projection that is received within the female opening, and

wherein the male projection is “T”-shaped and includes first and second arms and further comprising first and second gaps defined between the first and second arms and the female opening and wherein the polymeric material is located in the first and second gaps.

18. The rotor assembly of claim 17 , wherein the polymeric material includes resin.

19. The rotor assembly of claim 18 , wherein the resin is selected from a group consisting of epoxy, polyurethane, polyester, bismaleimide, acrylic, cyanate ester, polyimide, phenolic, benzoxazine, and vinyl ester.

20. The rotor assembly of claim 18 , wherein the resin further includes a discontinuous fill material.

21. The rotor assembly of claim 20 , wherein the discontinuous fill material includes one or more materials selected from a group consisting of silica, alumina, minerals, boron nitride, aluminum nitride, silicon nitride, basalt, and glass fibers.