Electronically commutated motor, stationary and rotatable assemblies therefore, and lamination

• US 4,327,302 A
• Filed: 09/21/1979
• Issued: 04/27/1982
• Est. Priority Date: 09/21/1979
• Status: Expired due to Term

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Hershberger, Doran D.
• Primary Examiner(s): Duggan, Donovan F.
• Application Number:
  US06/077,784
• Time in Patent Office: 949 Days
• Field of Search: 310/181, 310/156, 310/211, 310/182, 310/183, 310/184, 310/162-165
• US Class Current: 310/156.56
• CPC Class Codes: D06F 37/304 Arrangements or adaptations of electric motors
• CPC Class Codes: D06F 37/40 for driving the receptacle and an agitator or impeller, e.g. alternatively D06F37/304, D06F37/308 take precedence
• CPC Class Codes: H02K 1/2766 having a flux concentration effect

Abstract

A lamination adapted to be used in a dynamoelectric machine. The lamination has a body of generally thin ferromagnetic material, and a plurality of pole sections are spaced apart from each other generally about the body. A plurality of means on the body are interposed between adjacent ones of the pole sections for bridging therebetween, respectively, and a plurality of other pole sections on the body are interposed in spaced relation between the adjacent ones of the first named pole sections, respectively. A plurality of pairs of other means on the body are interposed between the adjacent ones of the first named pole sections and the other pole sections for bridging therebetween, respectively.

An electronically commutated motor, a stationary assembly therefor, and a rotatable assembly therefor are also disclosed.

Claims

1. A lamination adapted to be used in a core of a dynamoelectric machine, the lamination comprising:

a unitary body of generally thin ferromagnetic material;

an outer peripheral edge of said body;

an inner peripheral edge on said body and spaced generally radially from said outer peripheral edge;

a plurality of generally V-shaped openings through said body between said outer peripheral edge and said inner peripheral edge and disposed with respect to each other generally in arcuate spaced relation about said body, said openings each having first and second leg parts converging toward each other generally in a direction from said outer peripheral edge toward said inner peripheral edge, said first and second leg parts including first and second pairs of opposed side edges, first and second end edges interposed between said first and second side edge pairs and spaced adjacent said outer peripheral edge, and a common end edge interposed between one of said opposed side edges of said first and second side edge pairs and spaced adjacent said inner peripheral edge, respectively;

a plurality of first pole sections on said body between opposite ones of said one opposed side edges of said first and second side edge pairs in adjacent ones of said openings and extending generally between said outer peripheral edge and said inner peripheral edge, respectively;

a plurality of bridges on said body between said common end edges and said inner peripheral edge and integrally interconnected between adjacent ones of said first pole sections, respectively;

a plurality of second pole sections on said body disposed between the other of said opposed side edges of said first and second side edge pairs and extending from said outer peripheral edge generally toward said inner peripheral edge, said second pole sections including a plurality of free end edges interposed between said other opposed side edges of said first and second side edge pair and spaced from said bridges, respectively; and

a plurality of pairs of bridges on said body between said outer peripheral edge and said first and second end edges of said first and second leg parts and integrally interconnected between said first pole sections and said second pole sections, respectively.

20. A lamination as set forth in claim 1 wherein said second pole sections include a plurality of other openings intersecting with said free end edges, respectively.

2. A lamination adapted to be used in a core of a dynamoelectric machine, the lamination comprising:

a unitary body of generally thin ferromagnetic material;

a pair of generally radially spaced apart peripheral edges on said body;

a plurality of openings through said body between said peripheral edges thereof, respectively;

a plurality of first pole sections on said body between said openings and extending generally between said peripheral edges, respectively;

a plurality of means on said body interposed between said openings and one of said peripheral edges for bridging between adjacent ones of said first pole sections of said plurality thereof, respectively;

a plurality of second pole sections extending from the other of said peripheral edges into said openings between said adjacent ones of said first pole sections and in spaced relation therewith, respectively; and

a plurality of pairs of other means on said body interposed between said openings and said other peripheral edge for bridging between said first pole sections and said second pole sections, respectively.

3. A lamination as set forth in claim 2 wherein said second pole sections include a pair of opposite tabs integrally formed therewith and extending into said openings, respectively.

4. A lamination as set forth in claim 2 further comprising a plurality of amortisseur winding accommodating openings extending through at least one of said first pole sections and said second pole sections, respectively.

5. A lamination as set forth in claim 2 wherein said adjacent ones of said first pole sections include a pair of opposed marginal edges disposed between said first named bridging means and said other bridging means pair so as to define in part said openings, respectively, and a pair of opposite marginal edges on said other pole sections arranged generally in facing relation with said opposed marginal edges so as to also define in part said openings, respectively.

6. A lamination as set forth in claim 2 wherein said openings include a first pair of opposed marginal edges on said adjacent ones of said first pole sections, a second pair of opposite marginal edges on said second pole sections and arranged generally in opposed relation with said first opposed marginal edge pair, a common marginal edge on said first named bridging means and interposed between said first opposed marginal edge pair, and a pair of end marginal edges on said other bridging means pair and interposed between opposed ones of said marginal edges of said first opposed marginal edge pairs and said second opposite marginal edge pairs, respectively.

7. A lamination as set forth in claim 6 wherein the openings further include a free end edge on said second pole sections interposed between said second opposite marginal edge pair and spaced adjacent said common marginal edge in opposed relation therewith, respectively.

8. A lamination adapted to be used in a core of a dynamoelectric machine, the lamination comprising:

a unitary body of generally thin ferromagnetic material;

a plurality of first pole sections spaced apart from each other generally about said body;

a plurality of means on said body and interposed between adjacent ones of said first pole sections for bridging therebetween, respectively;

a plurality of second pole sections on said body and interposed in spaced relation between said adjacent ones of said first pole sections;

respectively; and

a plurality of pairs of other means on said body and interposed between said adjacent ones of said first pole sections and said second pole sections for bridging therebetween, respectively.

9. A lamination as set forth in claim 8 further comprising a peripheral edge on said body and defined by said first name pole sections, said other pole sections and said other bridging means pairs, respectively.

10. A lamination as set forth in claim 8 further comprising a peripheral edge on said body defined by said first named pole sections and said first named bridging means, respectively.

11. A lamination as set forth in claim 8 further comprising a pair of peripheral edges on said body arranged generally in radially spaced relation with each other, one of said peripheral edges being respectively defined by said first named pole sections, said other pole sections and said other bridging means pairs and the other of said peripheral edges being respectively defined by said first named pole sections and said first named bridging means.

12. A lamination as set forth in claim 8 wherein said other pole sections each includes a pair of tabs integral therewith and extending generally toward said adjacent ones of said first named pole sections, respectively.

13. A lamination as set forth in claim 8 further comprising a plurality of generally V-shaped openings extending through said body and defined between said second pole sections and said adjacent ones of said first pole sections and between said first named bridging means and said other bridging means pairs, respectively.

14. A lamination as set forth in claim 8 further comprising a plurality of openings extending through said body, each of said openings of said plurality thereof including a first pair of edges on said adjacent ones of said first pole sections, a second pair of edges on said second pole sections and arranged generally in opposed relation with said first edge pair, a common edge on said first named bridging means and interposed between said first edge pair, and a pair of spaced apart end edges interposed between adjacent opposed edges of said first and second edge pairs and arranged generally in opposed relation with said common edge, respectively.

15. A lamination as set forth in claim 8 wherein said second pole sections respectively include an end portion spaced adjacent said first named bridging means, and an opening intersecting only with said end portion and extending through said body.

16. A rotatable assembly adapted to be used in a dynamoelectric machine, the rotatable assembly comprising:

a ferromagnetic core having a peripheral portion interposed between a pair of opposite end faces;

a bore in said core intersecting with said opposite end faces;

a plurality of slots intersecting with said peripheral portion between said opposite end faces and arranged generally in arcuate spaced relation with each other about said core, said slots each including a pair of opposed sidewalls converging generally toward each other in a direction from said peripheral portion toward said bore, and a base wall generally adjacent said bore interposed between said opposed sidewalls;

a plurality of pairs of opposed flanges on said core extending between said opposite end faces at least adjacent said peripheral portion and said flange pairs each being arranged so as to protrude into said slots past said opposed sidewalls thereof, respectively;

a plurality of ferromagnetic pole sections arranged in said slots between said opposed sidewalls thereof and said opposed flanges, respectively, said pole sections each including another peripheral portion arranged so as to be at least generally coextensive with said first named peripheral portion on said core, a pair of opposite sidewalls converging generally toward each other in a direction from said another peripheral portion toward said bore so as to be arranged generally in facing relation with said opposed sidewalls of said slots and said opposed flanges, another base wall interposed between said opposite sidewalls and arranged generally in facing relation with said first named base wall, and a pair of opposite seats integral with said opposite sidewalls at least generally adjacent said another base wall and extending generally toward said opposed sidewalls of said slots, respectively;

a plurality of pairs of magnetic material elements arranged within said slots in abutting engagement between said opposed sidewalls of said slots and said opposite sidewalls of said pole sections and with a part of said magnet material element pairs engaged with said seats on said pole sections, respectively; and

a hardenable non-magnetic material solidified in place within said slots so as to generally fill the interstices thereof between said flange pairs and said magnetic material element pairs and between said pole sections and parts of said core adjacent thereto, said hardenable material acting with said magnetic material element pairs to not only define the polarity of said pole sections from said adjacent core parts but also to retain said pole sections against displacement from said slots, respectively.

17. A rotatable assembly adapted to be used in a dynamoelectric machine, the rotatable assembly comprising:

a ferromagnetic core having a plurality of first pole sections of like polarity spaced generally thereabout and defining in part a peripheral portion of said core;

a plurality of second pole sections having a polarity opposite that said first pole sections of and arranged in selected positions about said core between adjacent ones of said first pole sections, respectively;

a plurality of pairs of magnetic material elements engaged between said second pole sections and said adjacent ones of said first pole sections, respectively; and

a hardenable non-magnetic material solidified in said core between said first and second pole sections and said pairs of magnetic material elements so as to not only define the polarities of said first and second pole sections from each other but also prevent displacement of said second pole sections from their selected positions, respectively.

18. A rotatable assembly as set forth in claim 17 wherein said second pole sections include means therein for gripping engagement with said hardenable non-magnetic material solidified in said core, and said first pole sections include means arranged at least adjacent said peripheral portion for abutment with said hardenable non-magnetic material solidified in said core, the coaction of said gripping engagement means and said abutment means with said hardenable non-magnetic material solidified in said core acting to prevent the displacement of said second pole sections from their selected positions, respectively.

19. A rotatable assembly adapted for use in a dynamoelectric machine, the rotatable assembly comprising:

a ferromagnetic core having a peripheral portion;

a plurality of ferromagnetic pole sections;

a plurality of means in said core at least adjacent said peripheral portion for receiving said pole sections; and

means for magnetically defining the polarity of said pole sections from parts of said core adjacent thereto and for retaining said pole sections against displacement from said receiving means generally toward said peripheral portion of said core, said defining and retaining means including a plurality of sets of magnetic material elements abutted in engagement between said pole sections and said adjacent parts of said core, and a hardenable non-magnetic material solidified in said receiving means between said pole sections, said adjacent parts of said core and said magnetic material element sets, respectively.

22. A stationary assembly as set forth in claim 19 wherein said slot plurality includes at least twenty six slots.

23. A stationary assembly as set forth in claim 19 wherein said preselected number of said teeth is at least three.

24. A stationary assembly as set forth in claim 19 wherein at least some of said coils in at least some of said winding stages of said at least three thereof are interconnected and successively wound.

26. A stationary assembly as set forth in claim 23 wherein said slot plurality comprises at least twenty-six slots.

27. A stationary assembly as set forth in claim 23 wherein said core includes a plurality of teeth interposed between adjacent ones of said slots, and said each coil in said each winding stage spanning at least three teeth.

28. A stationary assembly as set forth in claim 23 wherein at least some of said coils in at least some of said winding stages span at least four of said slots, respectively.

29. A stationary assembly as set forth in claim 23 wherein at least some of said coils in at least some of said winding stages are interconnected and successively wound.

30. A stationary assembly as set forth in claim 23 wherein said slots each include a top section and a bottom section, respectively, and said one opposite side turn portion of all of said coils except said two coils in said other of said two winding stages and said third one winding stage being disposed in one of said top section and said bottom section, respectively.

31. An electronically commutated motor as set forth in claim 26 wherein said some poles each include a pair of opposite means extending therefrom into said receiving means generally toward said adjacent other poles for seating engagement with said magnetic material element pairs, respectively.

35. An electronically commutated motor as set forth in claim 26 wherein said adjacent other poles each include a pair of opposed flanges extending therefrom into said receiving means generally toward said some poles, said hardenable material having parts thereof caged between said opposed flange pair of said plurality thereof and said magnetic material element pairs, respectively.

36. An electronically commutated motor as set forth in claim 26 wherein said adjacent other poles are structurally interconnected with each other and have a like polarity different than that of said some poles, respectively.

37. An electronically commutated motor as set forth in claim 26 wherein said other of said one and other cores includes a pair of opposite end members, a plurality of openings extending through at least one of said some poles and said other poles between said opposite end members, and means in said plurality of openings and associated with said opposite end members for defining therewith an amortisseur winding of said other of said one and other core.

21. A stationary assembly adapted to be used in a dynamoelectric machine, the stationary assembly comprising;

a ferromagnetic core having a peripheral portion interposed between a pair of opposite end faces, said core including a plurality of generally radially extending teeth each having an inner tip defining in part a bore extending generally axially through said core between said opposite end faces thereof, and a plurality of slots arranged between adjacent ones of said teeth so as to intersect with said bore and extending between said opposite end faces, each of said slots having a top section and a bottom section with said top section being adjacent said bore, respectively;

a multi-stage winding arrangement associated with said core and having at least three winding stages each including a plurality of coils spanning a preselected number of said teeth, and each of said coils having at least one conductor turn and a pair of opposite side turn portions, respectively, at least half of said coils in each of said at least three winding stages having one of said opposite side turn portions thereof sharing a plurality of individual ones of said slots with one of said opposite side turn portions of another coil in a same winding stage, said one opposite side turn portion of said at least half of said coils and said one opposite side turn portion of said another coil in said same winding stage being disposed in one of said top section and said bottom section of said individual ones of said slots, respectively, a first pair of said coils in one of said winding stages of said at least three winding stages having one of said opposite side turn portions thereof disposed in one of said top section and said bottom section of a first pair of said slots and a second pair of said coils in another of said winding stages of said at least three winding stages having one of said opposite side turn portions thereof disposed in the other of said top section and said bottom section of said first slot pair, respectively, a third pair of said coils in one of said one winding stage and and said another winding stage having one of said opposite side turn portions thereof disposed in one of said top section and said bottom section of a second pair of said slots and a fourth pair of said coils in a third one of said winding stages of said at least three winding stages having one of said opposite side turn portions thereof disposed in the other of said top section and said bottom section of said second slot pair, respectively, a fifth pair of said coils in the other of said one winding stage and said another winding stage having one of said opposite side turn portions thereof disposed alone in a third pair of said slots, respectively, and a sixth pair of said coils in said third one of said winding stages having one of said opposite side turn portions thereof disposed alone in a fourth pair of said slots, respectively.

25. A stationary assembly adapted to be used in a dynamoelectric machine, the stationary assembly comprising:

a ferromagnetic core having a plurality of winding receiving slots therein;

a multi-stage winding arrangement associated with said slots of said plurality thereof and including at least three winding stages, each of said winding stages of said at least three thereof having a plurality of coils, each of said coils in said each winding stage having at least one conductor turn and a pair of opposite side turn portions, respectively, most of said coils in said each winding stage having one of said opposite side turn portions thereof sharing individual ones of said slots with one of said opposite side turn portions of other coils in the same winding stage, respectively, one of said coils in two of said winding stages each having one of said opposite side turn portions thereof disposed in one slot of a first pair thereof and another of said coils in said two winding stages each having one of said opposite side turn portions thereof disposed in the other slot of said first pair thereof, respectively, a third coil in one of said two winding stages and one coil in a third one of said winding stages of said at least three winding stages each having one of said opposite side turn portions thereof disposed in one slot of a second pair thereof and a fourth coil in said one of said two winding stages and another coil in said third one winding stage each having one of said opposite side turn portions thereof disposed in the other slot of said second pair thereof, and two coils in the other of said two winding stages and said third one winding stage each having said opposite side turn portions thereof disposed in a third pair of said slots and a fourth pair of said slots, respectively.

32. A stationary assembly adapted to be used in a dynamoelectric machine, the stationary assembly comprising:

a ferromagnetic core having a plurality of winding receiving slots;

a multi-stage winding arrangement including a plurality of winding stages each having a plurality of coils and each of said coils having at least one conductor turn with side turn portions thereof received in said slots of said plurality thereof, some of said coils in said each winding stage having said side turn portions thereof sharing slots only with said side turn portions of other of said coils in the same winding stage, two pairs of said coils in one of said winding stages having side turn portions sharing slots with side turn portions of two pairs of said coils in another two of said winding stages, respectively, and another two pair of said coils in said another two winding stages having side turn portions which do not share slots, respectively.

33. An electronically commutated motor comprising:

a ferromagnetic stator having a bore therein;

a plurality of winding receiving slots in said stator and intersecting with said bore;

a multi-stage winding arrangement associated with said slots of said plurality thereof and including at least three winding stages adapted to be commutated in at least one preselected sequence, each of said winding stages having a plurality of coils, each of said coils in said each winding stage having at least one conductor turn and a pair of opposite side turn portions, respectively, some of said coils in said each winding stage having at least one of said opposite side turn portions thereof disposed in individual ones of said slots with one of said opposite side turn portions of another of said coils in a same winding stage, respectively, one of said coils of two winding stages each having one of said opposite side turn portions thereof disposed in one slot of a first pair thereof and another of said coils of said two winding stages each having one of said opposite side turn portions thereof disposed in the other slot of said first slot pair, respectively, a third coil in one of said two winding stages and one coil in a third winding stage each having one of said opposite side turn portions thereof disposed in one slot of a second pair thereof and a fourth coil in said one of said two winding stages and another coil in said third winding stage each having one of said opposite side turn portions thereof disposed in the other slot of said second slot pair, and two coils of said coil plurality in the other of said two winding stages each having one of said opposite sides thereof disposed in a third pair of said slots, respectively;

a rotor disposed at least in part within said stator bore in magnetic coupling relation with said at least three winding stages and including a peripheral portion interposed between a pair of opposite end faces and arranged generally in coaxial relation with said stator bore, a shaft receiving opening extending through said rotor and intersecting with said opposite end faces, a plurality of discrete first pole sections integrally interconnected with each other and arranged in spaced relation generally about said rotor between said opposite end faces thereof, respectively, a plurality of other slots intersecting said peripheral portion between said opposite end faces and interposed between adjacent ones of said first pole sections, respectively, said other slots of said plurality there each having a pair of opposed sidewalls converging generally toward each other in a direction from said peripheral portion toward said shaft receiving opening with a base wall adjacent thereto interposed between said opposed sidewalls, and a plurality of pairs of opposed flanges extending between said opposite end faces at least adjacent said peripheral portion with said opposed flanges arranged so as to protrude into said other slots past said opposed sidewalls thereof, respectively;

a plurality of discrete second pole sections arranged in said other slots between said opposed sidewalls thereof, respectively, said second pole sections each including another peripheral portion arranged so as to be at least generally coextensive with said first named peripheral portion, a pair of opposite sidewalls converging generally toward each other in a direction from said another peripheral portion toward said shaft receiving opening so as to be arranged generally in facing relation with said opposed sidewalls of said other slots and said opposed flanges, an end wall interposed between said opposite sidewalls and arranged generally in facing relation with said base wall, and a pair of opposite seats integral with said opposite sidewalls at least generally adjacent said end wall and extending generally toward said opposed sidewalls of said other slots respectively;

a plurality of pairs of magnetic material elements arranged in abutting engagement between said opposed sidewalls of said other slots and said opposite sidewalls of said second pole sections and with parts of said magnetic material element pairs engaged with said seats on said second pole sections, respectively; and

a hardenable non-magnetic material solidified in place within said other slots generally filling them and disposed between said flanges, said magnetic material element pairs, said first pole sections and said second pole sections so as to not only retain said second pole sections against displacement from said other slots but also to magnetically define the polarity of said first pole sections from that of said second pole sections, respectively.

34. An electronically commutated motor comprising:

a pair of ferromagnetic cores arranged at least in part generally in coaxial spaced relation with each other and with one of said cores being rotatable relative to the other thereof;

a plurality of winding stages arranged generally about one of said one and other cores and adapted to be commutated in at least one preselected sequence;

a plurality of discrete magnetic pole sections arranged generally about the other of said one and other cores so as to be disposed in magnetic coupling relation with said winding stages upon the commutation thereof in the at least one preselected sequence, respectively;

a plurality of means arranged generally about said other of said one and other cores for receiving some of said pole sections in spaced relation between adjacent other pole sections, respectively; and

means caged in said receiving means between said some pole sections and said adjacent other pole sections not only for maintaining said some pole sections against dispalcement from said receiving means but also for magnetically defining the polarity of said some pole sections from that of said adjacent other poles, respectively.

38. An electronically commutated motor comprising:

a stationary assembly including a ferromagnetic core with at least three winding stages arranged generally thereabout and adapted to be energized in a preselected sequence;

a rotatable assembly including another ferromagnetic core rotatably arranged with said first named core;

a plurality of discrete first pole sections of like polarity arranged generally about said another core in magnetic coupling relation with said at least three winding stages upon the energization thereof and defining in part a peripheral portion of said another core, respectively;

a plurality of discrete second pole sections of a polarity opposite that of said first pole sections and arranged generally in preselected positions about said another core between adjacent ones of said first pole sections in magnetic coupling relation with said at least three winding stages upon the energization thereof, said second pole sections also defining in part said peripheral portion of said another core, respectively;

a plurality of pairs of magnetic material elements engaged between said second pole sections and said adjacent ones of said first pole sections and also seated on at least one of said first and second pole sections, respectively; and

a hardenable non-magnetic material in said another core and solidified in place between said adjacent ones of said first pole sections, said second pole sections and said magnetic material element pairs not only to retain said second pole sections against displacement from their preselected positions but also to magnetically define said second pole sections from said adjacent ones of said first pole sections, respectively.

39. An electronically commutated motor comprising:

a rotatable assembly having a plurality of polar regions;

a stationary assembly associated in magnetic coupling relation with said rotatable assembly and including a plurality of winding receiving slots with the number of said slots being different than the product of an integer greater than zero multiplied by the number of said polar regions in said rotatable assembly, and a multi-stage winding arrangement having a plurality of winding stages adapted for commutation in at least one preselected sequence with each winding stage having a plurality of coils distributed in said slots generally about said stationary assembly.

40. An electronically commutated motor comprising:

a rotatable assembly having a plurality of polar regions;

a stationary assembly associated in magnetic coupling relation with said rotatable assembly, and said stationary assembly including a plurality of winding receiving slots, and a multi-stage winding arrangement having a plurality of winding stages adapted for commutation in at least one preselected sequence with each winding stage having a plurality of coils distributed in said slots wherein the number of said slots is equal to the product of an integer greater than zero multiplied by the number of said polar regions in said rotatable assembly and with the product being increased or decreased by another integer not less than one or greater than two.

41. An electronically commutated motor as set forth in claim 40 further comprising a plurality of means in said another core for receiving said second pole sections in the preselected positions thereof and said magnet material element pairs, said hardenable material being solidified in place within said receiving means, respectively.

42. An electronically commutated motor as set forth in claim 40 wherein said adjacent ones of said first pole sections each include a pair of flanges extending generally toward said second pole sections, said hardenable material having parts thereof interposed between said flanges and said magnetic material element pairs thereby to cage said second pole sections in their preselected positions in said another core between said adjacent ones of said first pole sections, respectively.

43. An electronically commutated motor as set forth in claim 40 wherein said another core includes a bore therethrough, a shaft received in said bore, and means associated with said stationary assembly for rotatably journaling said shaft.

44. An electronically commutated motor comprising:

a pair of reltatively rotatable ferromagnetic cores;

a plurality of winding receiving slots in one of said cores;

a multi-stage winding arrangement including a plurality of winding stages adapted to be energized in a preselected sequence, each of said winding stages having a plurality of coils with each of said coils thereof having at least one conductor turn with side turn portions thereof received in said slots, some of said coils in said each winding stage having side turn portions thereof sharing slots only with side turn portions of other of said coils in the some winding stage, two pairs of said coils in one of said winding stages having side turn portions sharing slots with said side turn portions of two pairs of said coils in another two of said winding stages, respectively, and another pair of coils in one of said another two winding stages having side turn portions which do not share slots; and

a plurality of discrete pole sections arranged generally about the other of said cores so as to be magnetically coupled with said each winding stage upon the energization thereof, respectively.

45. An electronically commutated motor as set forth in claim 44 wherein said slot plurality includes at least twenty-six slots.

46. An electronically commutated motor as set forth in claim 44 wherein said each coil in said each winding stage spans at least four slots.

47. An electronically commutated motor as set forth in claim 44 wherein each said coil in at least some of said winding stages are interconnected and successively wound.

48. An electronically commutated motor as set forth in claim 44 wherein said slots each include a top section and a bottom section, respectively, and most of said coils of said plurality thereof being disposed in a lapped association with one side turn portion thereof positioned in one of said top section and bottom section of individual ones of said slots and with an opposite side turn portion thereof positioned in the other of said top section and bottom section of in other individual ones of said slots.

49. A rotatable assembly adapted to be used in a dynamoelectric machine, the rotatable assembly comprising:

a ferromagnetic core having a peripheral portion interposed between a pair of opposite end faces;

a plurality of slots in said core extending between said opposite end faces and intersecting with said peripheral portion, respectively;

a plurality of ferromagnetic pole pieces disposed in said slots and each having a pair of opposite seats extending therefrom, respectively;

a plurality of sets of magnetic material elements arranged in said slots between said pole pieces and said core so as to be engaged with said opposite seats on said pole pieces, respectively; and

a hardenable non-magnetic material solidified within said slots and acting with said magnetic material element sets not only to define the polarity of said pole pieces from that of parts of said core generally adjacent thereto but also to retain said pole pieces against displacement from said slots, respectively.

50. A rotatable assembly as set forth in claim 49 further comprising a plurality of pairs of flanges on said core and extending into said slots at least adjacent said peripheral portion of said core, respectively, said hardenable material being interconnected between said flange pairs and said magnetic material elements sets, respectively.

51. A rotatable assembly as set forth in claim 49 wherein said pole pieces each include a pair of opposite sidewalls, said opposite seats extending from said opposite sidewalls, and said slots each including a pair of opposed sidewalls, said magnetic material elements sets being engaged between adjacent ones of said opposite sidewalls and said opposed sidewalls, respectively.

52. A rotatable assembly as set forth in claim 49 wherein said hardenable material is solidified in place within said slots, respectively.

53. A rotatable assembly as set forth in claim 49 a plurality of openings in at least one of said core and said pole pieces and extending therethrough between said opposite end faces, and means within said opening defining at least in part an amortisseur winding of said core.