USRE31950E — Alternating current generators and motors

Claim 1

Independent Claim 267 words

An alternating current electrical machine comprising a stator having an inner periphery with slots containing conductors of a distributed winding, and a rotor mounted to rotate with its outer periphery adjacent to the inner periphery of the stator, the rotor comprising a plurality of permanent .[.magnets,.]. .Iadd.magnet means .Iaddend.spaced apart along the axis of rotation of the rotor with their .[.magnetic axes coincident with the said axis and, with their.]. directions of magnetization parallel to the said axis, a plurality of .Iadd.main .Iaddend.pole shoes spaced apart around the rotor periphery .[.and extending substantially continuously for at least three-quarters of the whole axial length of the rotor periphery.]., and a plurality of flux guides arranged to couple the poles of the permanent .[.magnets.]. .Iadd.magnet means .Iaddend.to the .Iadd.main .Iaddend.pole shoes magnetically to give the .Iadd.main .Iaddend.pole shoes polarities which alternate around the rotor periphery but which are the same in the axial direction of the rotor over more than half the length of the outer periphery of the rotor, the flux guides and the .Iadd.main .Iaddend.pole shoes being arranged to ensure that the flux density at the .Iadd.main .Iaddend.pole shoes is high compared with that at the permanent magnet means.Iadd., and the rotor including a speed stabilizing region having a periphery substantially formed from a plurality of circumferentially spaced salient portions of magnetic material defining spaces therebetween and a coupling portion joining substantially every salient portion to its neighboring salient portions on both sides thereof by means of a path in magnetic material, said path not including the permanent magnet means or any axial shaft for the rotor.Iaddend..

Claim 2

Dependent Claim 267 words

An alternating current electrical machine comprising a stator having an inner periphery with slots containing conductors of a distributed winding, and a rotor mounted to rotate with its outer periphery adjacent to the inner periphery of the stator, the rotor comprising a plurality of permanent .[.magnets,.]. .Iadd.magnet means .Iaddend.spaced apart along the axis of rotation of the rotor with their .[.magnetic axes coincident with the said axis and, with their.]. directions of magnetization parallel to the said axis, a plurality of .Iadd.main .Iaddend.pole shoes spaced apart around the rotor periphery .[.and extending substantially continuously for at least three-quarters of the whole axial length of the rotor periphery.]., and a plurality of flux guides arranged to couple the poles of the permanent .[.magnets.]. .Iadd.magnet means .Iaddend.to the .Iadd.main .Iaddend.pole shoes magnetically to give the .Iadd.main .Iaddend.pole shoes polarities which alternate around the rotor periphery but which are the same in the axial direction of the rotor over more than half the length of the outer periphery of the rotor, the flux guides and the .Iadd.main .Iaddend.pole shoes being arranged to ensure that the flux density at the .Iadd.main .Iaddend.pole shoes is high compared with that at the permanent magnet means.Iadd., and the rotor including a speed stabilizing region having a periphery substantially formed from a plurality of circumferentially spaced salient portions of magnetic material defining spaces therebetween and a coupling portion joining substantially every salient portion to its neighboring salient portions on both sides thereof by means of a path in magnetic material, said path not including the permanent magnet means or any axial shaft for the rotor.Iaddend..

Claim 3

Dependent Claim 24 words

A machine according to claim 1 wherein the conductors of the stator winding extend substantially the whole axial length of the outer rotor periphery.

Claim 4

Dependent Claim 26 words

A machine according to claim 2 wherein at least half the .Iadd.main .Iaddend.pole shoes extend for substantially the whole axial length of the outer rotor periphery.

Claim 5

Dependent Claim 29 words

A machine according to claim 3 wherein the stator winding is wound to provide a number of poles equal to the number of .Iadd.main .Iaddend.pole shoes of the rotor.

Claim 6

Dependent Claim 89 words

A machine according to claim .[.4.]. .Iadd.1 .Iaddend.wherein the permanent .[.magnets.]. .Iadd.magnet means .Iaddend.have like poles adjacent but separated by radial elements of the flux guides, the elements extending in a radial direction with respect to the said axis, radial elements of the guides also being positioned at the outer ends of the outer magnetic means in the rotor, and the .Iadd.main .Iaddend.pole shoes being elongated, with their axes generally parallel to the said axis and with each .Iadd.main .Iaddend.pole shoe magnetically coupled to at least one element. .[.

Claim 7

Dependent Claim 104 words

A machine according to claim 5 wherein alternate pole shoes extend only part of the way along the rotor periphery in the axial direction and auxiliary pole shoes occupy positions in the rotor periphery which are generally axially aligned with the said alternate pole shoes, the auxiliary pole shoes being supported by one of the elements which also support the adjacent full length pole shoes and the auxiliary pole shoes and the elements supporting those shoes being of a material which would allow the rotor to start rotation by induction motor action if the stator winding were coupled to an appropriate alternating current source..].

Claim 8

Dependent Claim 17 words

A machine according to claim 5 wherein the .Iadd.main .Iaddend.pole shoes connect substantially axially aligned pole parts.

Claim 9

Dependent Claim 34 words

A machine according to claim 5 wherein the .[.magnets.]. .Iadd.magnet means .Iaddend.include at least one material of the group consisting of barium ferrite, strontium ferrite, ticonal, alnico or one of the samarium cobalt materials.

Claim 10

Dependent Claim 40 words

A machine according to claim 5 wherein each permanent magnet .Iadd.means .Iaddend.is a generally disc shaped magnet and each flux guide includes a generally disc shaped element, made of magnetic material, with radially projecting portions supporting the .Iadd.main .Iaddend.pole shoes.

Claim 11

Dependent Claim 30 words

A machine according to claim 9 wherein the magnets include at least one of the following materials: barium ferrite, strontium ferrite, ticonal, alnico or one of the samarium cobalt materials.

Claim 12

Dependent Claim 16 words

A machine according to claim 10 wherein the elements and .Iadd.main .Iaddend.pole shoes are of steel.

Claim 13

Dependent Claim 23 words

A machine according to claim 9 with one more flux guide than disc magnet, and each disc magnet being positioned between flux guides.

Claim 14

Dependent Claim 42 words

A machine according to claim 9 wherein in each pair of adjacent .Iadd.main .Iaddend.pole shoes, one pole shoe is supported by alternate disc shaped elements in the axial direction and the other pole shoe is supported by the remaining disc shaped elements.

Claim 15

Dependent Claim 38 words

A machine according to claim 13 wherein the rotor has an axial shaft at least the periphery of which is made of non-magnetic material, and the magnets and the elements have central apertures through which the shaft passes.

Claim 16

Dependent Claim 58 words

A machine according to claim 1, wherein the .Iadd.main .Iaddend.pole shoes are elongated in the said axial direction and are skewed relative to the rotor axis. .[.16. A machine according to claim 1, wherein the rotor includes a portion so constructed that with an appropriate alternating current source coupled to the stator winding, the rotor will begin to

Claim 17

Dependent Claim 58 words

rotate from rest by induction motor action..]. 17. A machine according to claim 1 wherein the .Iadd.main .Iaddend.pole shoes project in both directions parallel to the rotor axis away from at least some of the positions at which the .Iadd.main .Iaddend.pole shoes are coupled to flux guides situated between two permanent magnet means, and the pole shoes are

Claim 18

Dependent Claim 255 words

integral at the said positions. 18. A permanent magnet rotor for an alternating current generator or motor, including at least two generally disc shaped axially magnetised permanent magnets each having an aperture at its centre, on each side of which magnets are generally disc shaped elements of magnetic material with central apertures and a number of radially projecting pole parts on their outer peripheries, .Iadd.main .Iaddend.pole shoes arranged radially on the pole parts extending .[.substantially continuously for at least three quarters of the whole axial length of the rotor periphery.]. over the said elements in the axial direction, and a metal hub, having at least a periphery of non-magnetic material, which passes through the apertures in the magnets and the elements, the elements being so arranged that the pole parts of elements adjacent to permanent magnet poles of the same polarity are substantially axially aligned with one another and with gaps between the pole parts of elements adjacent to permanent magnet poles of the opposite polarity and the disc shaped elements, the pole parts and the pole shoes being arranged to ensure that the flux density at the pole shoes is high compared with that at the permanent magnets.Iadd., and the rotor including a speed stabilizing region having a periphery substantially formed from a plurality of circumferentially spaced salient portions of magnetic material defining spaces therebetween and a coupling portion joining substantially every salient portion to its neighboring salient portions on both sides thereof by means of a path in magnetic material, said path not

Claim 19

Dependent Claim 255 words

integral at the said positions. 18. A permanent magnet rotor for an alternating current generator or motor, including at least two generally disc shaped axially magnetised permanent magnets each having an aperture at its centre, on each side of which magnets are generally disc shaped elements of magnetic material with central apertures and a number of radially projecting pole parts on their outer peripheries, .Iadd.main .Iaddend.pole shoes arranged radially on the pole parts extending .[.substantially continuously for at least three quarters of the whole axial length of the rotor periphery.]. over the said elements in the axial direction, and a metal hub, having at least a periphery of non-magnetic material, which passes through the apertures in the magnets and the elements, the elements being so arranged that the pole parts of elements adjacent to permanent magnet poles of the same polarity are substantially axially aligned with one another and with gaps between the pole parts of elements adjacent to permanent magnet poles of the opposite polarity and the disc shaped elements, the pole parts and the pole shoes being arranged to ensure that the flux density at the pole shoes is high compared with that at the permanent magnets.Iadd., and the rotor including a speed stabilizing region having a periphery substantially formed from a plurality of circumferentially spaced salient portions of magnetic material defining spaces therebetween and a coupling portion joining substantially every salient portion to its neighboring salient portions on both sides thereof by means of a path in magnetic material, said path not

Claim 20

Dependent Claim 168 words

including the permanent magnets.Iaddend.. 19. A rotor according to claim 18 wherein the pole shoes connect substantially axially aligned pole parts. .Iadd.20. A machine according to claim 1 wherein the coupling portion includes a generally planar member of magnetic material positioned normal to the rotor axis. .Iaddend. .Iadd.21. A machine according to claim 20 wherein alternate main pole shoes extend only part of the way along the rotor periphery in the axial direction, and auxiliary pole shoes occupy positions in the periphery of the said stabilizing region which are substantially axially aligned with the said alternate main pole shoes, the auxiliary pole shoes being supported by one of the flux guides which forms the said coupling portion, and the auxiliary pole shoes and those portions of those main pole shoes which are between the alternate pole shoes and in the stabilizing region forming the said salient portions..Iaddend. .Iadd.22. A rotor according to claim 19 wherein the coupling portion includes a generally planar member of magnetic material positioned normal

Claim 21

Dependent Claim 106 words

to the rotor axis. .Iaddend. .Iadd.23. A rotor according to claim 22 wherein alternate main pole shoes extend only part of the way along the rotor periphery in the axial direction, and auxiliary pole shoes occupy positions in the periphery of the said stabilizing region which are substantially axially aligned with the said alternate main pole shoes, the auxiliary pole shoes being supported by one of the flux guides which forms the said coupling portion, and the auxiliary pole shoes and those portions of those main pole shoes which are between the alternate pole shoes and in the stabilizing region forming the said salient portions. .Iaddend.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1988-07-15	1989-01-14	1989-07-16	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1992-07-15	1993-01-14	1993-07-16	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1996-07-15	1997-01-14	1997-07-16	$7700.00	Window Closed / Lapsed

Alternating current generators and motors

Abstract

Inventors

Bibliographic Details

Claims Analysis

References Cited (Backward Citations)

USPTO Annuity & Maintenance Windows

Assigned Categories & Tags

Assign Category Tag