Slotless, brushless, large air-gap electric motor

• US 5,619,085 A
• Filed: 06/20/1995
• Issued: 04/08/1997
• Est. Priority Date: 12/15/1989
• Status: Expired due to Fees

• Current Assignee: Dynamic Energy Systems LLC
• Original Assignee: Daniel J. Shramo
• Inventors: Shramo, Daniel J.
• Primary Examiner(s): BUDD, MARK OSBORNE
• Application Number:
  US08/496,851
• Time in Patent Office: 658 Days
• Field of Search: 310/44, 310/90, 310/68 R, 310/68 B, 310/156, 310/179, 310/180-184, 310/190, 310/206-208, 310/258, 310/261, 318/254, 335/301
• US Class Current: 310/184
• CPC Class Codes: H02K 1/274 the rotor consisting of two or more circumferentially positioned magnets
• CPC Class Codes: H02K 11/33 Drive circuits, e.g. power electronics H02K11/38 takes precedence
• CPC Class Codes: H02K 15/0471 manufactured by flattening a spiral winding
• CPC Class Codes: H02K 21/14 with magnets rotating within the armatures
• CPC Class Codes: H02K 29/08 using magnetic effect devices, e.g. Hall-plates, magneto-resistors H02K29/12 takes precedence
• 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 5/1732 radially supporting the rotary shaft at both ends of the rotor H02K5/1737 takes precedence
• CPC Class Codes: H02K 5/18 with ribs or fins for improving heat transfer

Abstract

A polyphase electric motor includes a stator having a field winding and a field backiron, and a rotor disposed within the stator including a permanent magnet with a plurality of pole pairs, wherein the field winding includes a plurality of coil segments, each coil segment having a plurality of electrically conductive turns of a polygonal shape, the turns in each coil segment having circumferentially opposite sides, the circumferentially opposite sides of relatively adjacent turns being circumferentially offset with respect to one another in the same circumferential direction so that each coil segment occupies a length generally equal to the arcuate length of two pole faces, each coil segment further including a subsegment of turns electrically commutated in accordance with a different one of a plurality of field phases.

Claims

1. A polyphase electric motor, comprising:

a stator having a field winding and a field backiron; and

,

a rotor disposed within the stator including a permanent magnet with a plurality of pole pairs;

wherein the field winding includes a plurality of coil segments, each coil segment having a plurality of electrically conductive turns of a polygonal shape, the turns in each coil segment having circumferentially opposite sides, the circumferentially opposite sides of relatively adjacent turns being circumferentially offset with respect to one another in the same circumferential direction so that each coil segment occupies a length generally equal to the arcuate length of two pole faces, each the coil segment including a subsegment of turns electrically commutated in accordance with a different one of a plurality of field phases.

2. The motor of claim 1, wherein the polygonal shaped turns are rectangles.

3. The motor of claim 1, wherein corresponding subsegments of each coil segment are electrically connected in series.

4. The motor of claim 1, wherein corresponding subsegments of each coil segment are electrically connected in parallel.

5. The motor of claim 1, wherein the field winding is electrically connected to form a three phase winding.

6. The motor of claim 1, wherein the field winding is electrically connected to a commutation circuit in the form of a Wye.

7. The motor of claim 5, wherein each subsegment of a coil segment is commutated in the phase sequence φ

₁, -φ

₃, φ

₂ ;

where φ

_n equals the phase number.

8. A polyphase electric motor, comprising:

a stator having a field winding and a field backiron; and

,

a rotor disposed within the stator including a permanent magnet with a plurality of pole pairs;

wherein the field winding includes a plurality of coil segments, each coil segment having a plurality of electrically conductive turns of a polygonal shape and occupying a length generally equal to the arcuate length of two pole faces, each coil segment including a subsegment of turns electrically commutated in accordance with a different one of a plurality of field phases.