Axial gap electrical machine

• US 7,157,826 B2
• Filed: 02/28/2005
• Issued: 01/02/2007
• Est. Priority Date: 05/24/2001
• Status: Expired due to Fees

• Current Assignee: Mmillenniumm Group Incorporated
• Original Assignee: Arjona Indraeswaran Rajasingham
• Inventors: Rajasingham, Arjona Indraeswaran
• Primary Examiner(s): LE, DANG D
• Application Number:
  US11/067,277
• Publication Number:
  US 20060082239A1
• Time in Patent Office: 673 Days
• Field of Search: 310/268, 310/266, 310/196, 310/256, 310201-208, 296/05, 296/06
• US Class Current: 310/208
• CPC Class Codes: H02K 1/2795 the rotor consisting of two or more circumferentially positioned magnets
• CPC Class Codes: H02K 1/32 with channels or ducts for flow of cooling medium
• CPC Class Codes: H02K 21/24 with magnets axially facing the armatures, e.g. hub-type cycle dynamos
• CPC Class Codes: H02K 3/04 Windings characterised by the conductor shape, form or construction, e.g. with bar conductors
• CPC Class Codes: H02K 3/28 Layout of windings or of connections between windings windings for pole-changing H02K17/06, H02K17/14, H02K19/12, H02K19/32
• CPC Class Codes: H02K 3/47 Air-gap windings, i.e. iron-free windings
• CPC Class Codes: H02K 3/50 Fastening of winding heads, equalising connectors, or connections thereto
• CPC Class Codes: H02K 41/03 Synchronous motors; Motors moving step by step; Reluctance motors H02K41/035 takes precedence
• CPC Class Codes: H02K 7/083 radially supporting the rotary shaft at both ends of the rotor H02K7/086, H02K7/09 take precedence
• CPC Class Codes: H02K 7/12 with auxiliary limited movement of stators, rotors or core parts, e.g. rotors axially movable for the purpose of clutching or braking
• CPC Class Codes: H02K 9/00 Arrangements for cooling or ventilating channels or ducts in parts of the magnetic circuit H02K1/20, H02K1/32; channels or ducts in or between conductors H02K3/22, H02K3/24
• CPC Class Codes: Y10T 29/49071 by winding or coiling

Abstract

An axial gap electrical machine employs unique architecture to (1) overcome critical limits in the air gap at high speeds, while maintaining high torque performance at low speeds, while synergistically providing a geometry that withstands meets critical force concentration within these machines, (2) provides arrangements for cooling said machines using either a Pelletier effect or air fins, (3) “windings” that are produced as ribbon or stampings or laminates, that may be in some cases be arranged to optimize conductor and magnetic core density within the machine. Arrangements are also proposed for mounting the machines as wheels of a vehicle, to provide ease of removing and installing said motor.

Claims

1. A method for constructing a winding with at least one turn in an electrical machine with a contiguous conductor with local relative motion in the x-direetion of a 3 dimensional space with x-, y-, and z-directions between

a magnetic field element (102/103 FIG. 1, FIG. 9) with a plurality of pairs of poles, each pair of poles arranged to provide a magnetic field between a first member and a second member of said pairs of poles substantially in a y-direction orthogonal to said relative motion of said electrical machine, and wherein said plurality of pairs of poles are arranged to be along the local direction of motion of said electrical machine,

and wherein the first members of the pairs of poles comprise the first set of poles and the second members of the of the pairs of poles comprise the second set of poles;

and said winding with at least one turn (101 FIG. 1, FIG. 2A, FIG. 2B, FIG. 2J, 2K, 2K1, 2P, 2Q, 2U, 2X, 2Z1, 2Z2, 2Z2A, 2Z2B, 10A, 10B, 13A1, 13A2, 13B) by;

constructing a contiguous flat conductor with a first end and a second end (111c), wherein the contiguous conductor has a length, and a width “

w” and

a thickness “

t”

at each point along said length, and wherein the width is greater than the thickness at each point along said length, and said contiguous conductor having a first and second face across said thickness along said length of said conductor,

orienting said contiguous flat conductor such that it comprises at least one pair of working segments each comprising a first working segment and a second working segment along its length by

locating the first working segments adjoining the first set of poles at a distance of a first air gap (139), and

locating the second working segments adjoining the second set of poles at a distance of a second air gap (139),

furthermore, locating the first and second working segments to be separated in the y-direction by a non-zero distance,

orienting each of said working segments such that the width “

w”

of the continuous flat conductor along the length of said working segments lies substantially in the direction of said magnetic field in the y-direction (FIG. 2M, 2T, 10C, 13C),

orienting the first face of each of said pair of working segments to face the local direction of motion of said working segment in the electrical machine,

orienting the second face of each pair of working segments to face the direction opposite the local direction of motion of said working segment in the electrical machine,

wherein the first face of each member of each pair of working segments is on the first face of the contiguous flat conductor and the second face of each element of each pair of working segments is on the second face of the contiguous flat conductor,

orienting each segment of the contiguous flat conductor between any first working segment and the next second working segment along said contiguous flat conductor, comprising non-working segments, such that the first face of each non-working segment is contiguous with the first face of each of the first and second working segments contiguous with the non-working segment, and the second face of each non-working segment is contiguous with the second face of each of the first and second working segments contiguous with the non-working segment,

wherein the first face of the non-working segment lies on the first face of the contiguous flat conductor and the second face of the non-working segment lies on the second face of the contiguous flat conductor,

installing two connection means at the ends of the contiguous flat conductor,

reducing the spacing between consecutive first working segments, between consecutive second working segments, consecutive non-working segments between first and second working segments ordered from the first end to the second end along the contiguous flat conductor, and consecutive working segments between second and first working segments ordered from the first end to the second end along the contiguous flat conductor,

thereby forming one or more turns of a winding with the working and non-working segments packed together with the first face of the contiguous flat conductor on any segment always facing and adjacent to the second face of the contiguous flat conductor on another segment along substantially its entire length providing means for self bracing of adjacent surfaces of the winding, and all the first faces of working segments facing the local direction of motion of the windings and all the second faces of working segments facing in the direction opposite the direction of relative motion of the electrical machine.

2. A method for constructing a wound element of an electrical machine comprising the method of claim 1, for constructing multiple windings with at least one turn, further comprising:

interlocking said multiple windings with at least one turn, with the first face of the contiguous flat conductors of each of the windings with at least one turn in the same direction (FIG. 2L, 2M, 2N, 2S, 2T, 10C, 13C).

3. A method for constructing a wound element of an electrical machine comprising the method of claim 2, further comprising:

grinding the surface of the each of the stacks of working segments along the outer edge facing the air gap to a profile that matches the pole surface (FIG. 1).

4. A method for constructing a winding of an electrical machine comprising the method of claim 1, further comprising

attaching on one or both of the first and second faces of one or more of the working segments of the contiguous flat conductor, insulated magnetic core elements (2K, 2R, 2V, 10C, 13D).

5. A method for constructing a winding of an electrical machine comprising the method of claim 4, wherein said magnetic core elements are of length substantially equal to the width “

w”

of the contiguous flat conductor and oriented across the width of the contiguous flat conductor.

6. A method for constructing a winding of an electrical machine comprising the method of claim 4, wherein said magnetic core elements comprise powdered magnetic core material compacted and bonded to said working conductor segments.

7. A method for constructing a braced winding of an electrical machine comprising the method of claim 1, further comprising:

attaching a loop support (140;

FIG. 2W, 2Y, 2Y1, 2Y2) on one of the exposed first or the second side of the contiguous flat conductor for at least one of additional support of the winding, attaching windings to a support on the side of one or the other non-working conductors.

8. A method for constructing a winding of an electrical machine comprising the method of claim 1, wherein said contiguous flat conductor has a substantially constant width “

w”

, and comprises at each non-working conductor segment a folding arrangement on itself (FIG. 2Z1) whereby the direction of the conductor rotates by 180 degrees and shifts along its width by substantially a distance “

w”

thereby being adjacent to the section on the other side of the folding arrangement and the first face of the contiguous flat conductor on either end of the folding arrangement remaining on the same side of the conductor.

9. A method for constructing a winding of an electrical machine comprising the method of claim 1, wherein said contiguous flat conductor is constructed by:

constructing strips of conductor material of width greater than 2×

“

w”

,

splitting the conductor strips along their middle for all of their lengths except for an end section of approximately “

w”

thereby creating two parallel conductors of width “

w”

connected at one end with a section about “

w”

long (FIG. 2Z3) on each of the strips of conductor material forming a “

U”

with a first and a second leg,

attaching each of ends of the first legs of the U to the ends of a second leg of the “

U”

of another strip of conductor material (FIG. 2Z3 125B1–

2 sides),

forming the winding by bending sections for working segments (123B, 124B;

FIG. 2Z3, 2Z2A, 2Z2B) for angled sections of non-working segments (125B3, 125B4;

FIG. 2Z3, 2Z2A, 2Z2B) and connection sections of non-working segments (125B6, 125B2;

FIG. 2Z3, 2Z2A, 2Z2B) along with the connections to adjacent turns (125B1;

FIG. 2Z3, 2Z2A, 2Z2B).