GB2030375A - Laminated Winding in D.C. Motor - Google Patents
Laminated Winding in D.C. Motor Download PDFInfo
- Publication number
- GB2030375A GB2030375A GB7928908A GB7928908A GB2030375A GB 2030375 A GB2030375 A GB 2030375A GB 7928908 A GB7928908 A GB 7928908A GB 7928908 A GB7928908 A GB 7928908A GB 2030375 A GB2030375 A GB 2030375A
- Authority
- GB
- United Kingdom
- Prior art keywords
- winding
- hairpin
- laminated
- armature
- laminations
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
- 238000004804 winding Methods 0.000 title claims abstract description 168
- 238000003475 lamination Methods 0.000 claims abstract description 73
- 238000009826 distribution Methods 0.000 claims abstract description 10
- 238000009413 insulation Methods 0.000 claims description 15
- 239000002184 metal Substances 0.000 claims description 12
- 229910052751 metal Inorganic materials 0.000 claims description 12
- 239000004020 conductor Substances 0.000 claims description 2
- 230000009467 reduction Effects 0.000 description 7
- 238000005452 bending Methods 0.000 description 4
- 238000005219 brazing Methods 0.000 description 2
- 238000003860 storage Methods 0.000 description 2
- 238000009827 uniform distribution Methods 0.000 description 2
- 238000003466 welding Methods 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 239000002320 enamel (paints) Substances 0.000 description 1
- 238000007689 inspection Methods 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K3/00—Details of windings
- H02K3/04—Windings characterised by the conductor shape, form or construction, e.g. with bar conductors
- H02K3/12—Windings characterised by the conductor shape, form or construction, e.g. with bar conductors arranged in slots
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Windings For Motors And Generators (AREA)
Abstract
A hairpin-like winding, for the armature of a low voltage, high current, D.C. motor, is formed as a plurality of parallel-connected, insulated laminations to provide a distribution of current across the cross section of that winding which is more uniform than the distribution of current across a winding of unitary cross section. <IMAGE>
Description
SPECIFICATION
Winding Armature of Low Voltage, High
Current D.C. Motor
Background and Field of the Invention
The armature windings of many prior low voltage, high current, D.C. motors have been hairpin-like in configuration; and they have been unitary in cross section. The elongated sides of each of those windings were disposed in circumferentially-spaced coil slots in an armature, the free ends of each of those windings were mechanically secured and electrically bonded to the commutator of that armature, and the closed ends of those windings were disposed adjacent the opposite end of that armature.When current flowed through any of those hairpin-like armature windings, the current density became relativelyhigh in those portions of the cross section of that winding which were adjacent the surfaces of that winding, and the current density became relatively-low in the central portion of the cross section of that winding.
Summary of the Invention
The present invention provides a hairpin-like winding, for the armature of a low voltage, high current, D.C. motor, which is formed as a plurality of insulated, parallel-connected laminations.
When current flows through any of those laminations, the current density will become relatively high in those portions of the cross section of that lamination which are adjacent the surface of that lamination, and the current density will become relatively low in the central portion of the cross section of that lamination. Because at least one surface of each lamination will be disposed in a location which corresponds to a location in the central portion of an essentiallyidentical prior winding of unitary cross-section, the relatively-high current density adjacent that one surface will make the current density in the central portion of the laminated winding higher than the current density in the central portion of the essentialiy-identical winding of unitary cross section.The relatively-high current densities adjacent the central portion of the laminated winding, which are due to the relatively-high current densities adjacent the said one surfaces of the laminations of that winding, make the distribution of current across the cross section of the laminated winding more uniform than the distribution of current across the cross section of the essentially-identical winding of unitary cross section. That more uniform distribution of current across the cross section of that laminated winding makes the effective resistance, and hence the heat losses, of that laminated winding as much as ten percent to twenty percent lower than those of a substantially-identical winding of unitary cross section. It is, therefore, an object of the present invention to provide a hairpin-like winding, for the armature of a low voltage, high current, D.C.
motor, which is formed as a plurality of insulated, parallel-connected laminations.
Other and further objects and advantages of
the present invention should become apparent
from an examination of the drawing and
accompanying description.
In the drawing and accompanying description,
two preferred embodiments of the present
invention are shown and described but it is to be
understood that the drawing and accompanying
description are for the purpose of illustration only
and do not limit the invention and that the
invention will be defined by the appended claims.
Description of the Drawing
In the drawing Figure 1 is a generally plan-type
view of one winding which is made in accordance
with the principles and teachings of the present
invention,
Figure 2 is a side view of the winding of Fig. 1, Figure 3 is a sectional view, on an enlarged
scale, of one side of the winding of Figs. 1 and 2
and of one side of a similar winding as they
appear when disposed in a coil slot in the
armature of a low voltage, high current D.C.
motor,
Figure 4 is a side view of one-half of a further
winding which is made in accordance with the
principles and teachings of the present invention,
Figure 5 is a side view of the other half of the
further winding, and
Figure 6 is a broken view of the half-windings
of Figs. 4 and 5 before the left-hand ends thereof
are mechanically secured and electrically bonded
to each other to form that further winding.
Description of the Preferred Embodiment
Referring to the drawing in detail, the numeral
20 generally denotes one preferred embodiment
of hairpin-like winding, for a low voltage, high
current D.C. motor, which is made in accordance with the principles and teachings of the present
invention. Examples of such motors are the motors which are used to drive fork-lift trucks and golf carts and the motors which are used to operate pumps. That winding has three laminations 22, 26 and 30 which are made from low-resistance metal such as copper and which are rectangular in cross section. As shown particularly by Fig. 3, lamination 22 has a layer 24 of insulation which completely encloses all sides of that lamination. Similarly, the laminations 26 and 30, respectively, have layers of insulation 28 and 32 which completely enclose all sides of those laminations.Although different kinds of insulation could be used, the hard, high-dielectric enamel coating which is used on the conductors of electric motors and electric generators has been found to be very useful.
The insulating layer 28 on lamination 26 directly abuts the insulating layer 32 on lamination 30; and the insulating layer 24 on lamination 22 directly abuts the insulating layer 28 on lamination 26. As a result, the crosssectional area of the winding 20 is only a few thousandths of an inch deeper than the cross sectional area of an essentially-identical winding of unitary cross sections. The laminations 22, 26 and 30 of winding 20 will be suitably held in the abutting relation shown in Figs. 1-3 as that winding is placed in a bending fixture and bent to the configuration shown by Figs. 1 and 2. Prior to the time the winding 20 is placed in the bending fixture, short portions of the free ends of that winding will have the layers of insulation 24, 28 and 32 removed from the free ends of laminations 22, 26 and 30, respectively.
The numerals 34, 38 and 42 in Fig. 3 denote the laminations of a further winding which will be identical to winding 20. Layers of insulation 36, 40 and 44 completely enclose all sides of laminations 34, 38 and 42. As shown by Fig. 3, the insulating layer 40 abuts the insulating layer 44; and the insulating layer 36 abuts the insulating layer 40. As a result, the crosssectional area of that further winding is only a few thousandths of an inch deeper than the cross sectional area of an essentially-identical winding of unitary cross sections. The laminations 34, 38 and 42 will be suitably held in the abutting relation shown in Figs. 3 as the further winding is placed in a bending fixture and bent to a configuration identical to that shown for winding 20 in Figs. 1 and 2.Prior to the time the further winding is placed in the bending fixture, short portions of the free ends of that winding will have the layers 36, 40 and 44 removed from the free ends of laminations 34, 38 and 42, respectively.
Fig. 3 shows a portion of an armature 46 of a low voltage, high current D.C. motor; and the numeral 48 denotes an insulated liner for one of the slots 49 of that armature. The laminations 34, 38 and 42, which constitute one of the sides of the further winding, are disposed within the slot 49 and are located in the bottom of that slot, all as shown by Fig. 3. One side of the winding 20 is disposed in the top of slot 49; and that side abuts the upper surface of the one side of the further winding. A slot closure 50 closes the outer end of slot 49 and mechanically holds the one side of winding 20 and the one side of the further winding within that slot.Because the cross section of winding 20 is a few thousandths of an inch deeper than the cross section of an essentially-identical winding of unitary cross section, and because the cross section of the further winding also is a few thousandths of an inch deeper than the cross section of that essentially-identical winding of unitary cross section, the slot 49 is made a few thousandths of an inch deeper than a slot of an essentiallyidentical armature which accommodates the sides of two essentially-identical windings of unitary cross section.
The free ends of the winding 20, the free ends of the further winding, and the free ends of all of the other windings, not shown, of the armature 46 will be mechanically secured and electrically bonded to spaced-apart sections of the commutator of that armature in the standard and usual manner. As a result, the appearance of the armature 46 will be almost identical to the appearance of an essentially-identical armature which differs form the armature 46 solely in using windings of unitary cross section. A close inspection of the end turn of winding 20, of the end turn of the further winding, and of the end turns of the rest of the windings of armature 46 will, of course, show that each winding is made from a plurality of laminations and hence is not unitary in cross section.Importantly the electrical characteristics of the low voltage, high current
D.C. motor which includes armature 46 are much better than the corresponding electrical characteristics of an essentially-identical motor which includes an armature that has windings which are unitary, rather than laminated, in cross section.
Specifically, each winding of such an essentially-identical motor has four surfaces; and the current density adjacent those four surfaces will be considerably higher than the current density adjacent the central portion of the cross section of that winding. Each lamination of the winding 20 has four surfaces; and the current density adjacent those four surfaces will be considerably higher than the current density adjacent the central portion of the cross section of that lamination.Although the upper surface of lamination 22, the lower surface of lamination 30, the left-hand surfaces of laminations 22, 26 and 30, and the right-hand surfaces of laminations 22, 26 and 30 are counterparts of the upper, lower, left-hand and right-hand surfaces of an essentially-identical winding of unitary cross section, the winding 20 has four surfaces for which that essentially-identical winding of unitary cross section has no counterparts. Those surfaces are the lower surface of lamination 22, the upper and lower surfaces of lamination 26, and the upper surface of lamination 30.It should be noted that those four surfaces are disposed locations which correspond to locations, in the central portion of an essentially-identical'prior winding of unitary cross section, where the current density is low; and hence the reiatively-high current densities in the portions of those laminations adjacent those four surfaces make the distribution of current across the cross section of winding 20 more uniform than the distribution of current across the cross section of an essentially-identical winding of unitary cross section. That more uniform distribution of current densities throughout the cross section of winding 20 produces a reduction in the effective resistance of that winding, at speeds of from eighteen hundred to twenty-five hundred revolutions per minute, of from ten percent to twenty percent of the effective resistance of an essentially-identical winding of unitary cross section. That reduction in effective resistance provides a corresponding decrease in the heat (l2R) losses in the winding 20. These surprising and important reductions in effective resistance and in heat losses will be even higher where the winding 20 is used in the armature of a motor which is operated at speeds in excess of twenty-five hundred revolutions per minute.
The winding of the present invention is particularly useful in the armature of a motor having a voltage rating below one hundred volts, such as a motor having a nominal voltage rating of twenty-four volts, thirtysix volts, forty-eight volts, seventy-two volts or ninety-six volts. Such a winding of the present invention can be used in motors having a current rating of from as low as sixty amperes to as high as twelve hundred amperes. Such a motor frequently receives power from storage batteries or from static-type D.C.
power supplies.
Fig. 3 shows one side of winding 20 in the upper portion of slot 49, and it shows one side of the further winding in the bottom of that slot. The other side of winding 20 will be disposed in the bottom of a circumferentially-spaced slot, not shown; and the other side of that further winding will be disposed in the top of a further circumferentially-spaced slot. The other windings, not shown, of the armature 46 will each have one side thereof in the bottom of a slot and the other side thereof in the top of a circumferentiallyspaced slot. All of this means that armature 46 will differ from a corresponding prior art armature solely in the use of laminated, rather than unitary cross section windings; but will have a ten percent to twenty percent reduction in effective resistance, and in heat losses, because of that difference.
Referring particularly to Figs. 4-6, the numeral 52 generally denotes a half-winding which is made to have the configuration of a Zbar. That half-winding has three laminations 54, 56 and 58; and a thin layer of insulation encloses all sides of each of those laminations. The laminations 54, 56 and 58 are rectangular in cross section; and they could have the same cross sectional areas and configurations as half-lengths of the laminations 22, 26, and 30 of winding 20.
Short lengths of the opposite ends of each of the laminations of half-winding 52 are wholly devoid of insulation.
The numeral 60 in Figs. 5 and 6 generally denotes a half-winding which is a mirror image of the half-winding 52. That half-winding includes laminations 62, 64 and 66; and a thin layer of insulation encloses all sides of each of those laminations. Short lengths of the opposite ends of each of the laminations of half-winding 60 are wholly devoid of insulation.
As indicated by Figs. 6, the left-hand end of the half-winding 60 is disposed above, but in register with, the left-hand, end of the half-winding 52; and then the insulation-free lengths of the laminations of those half-windings are mechanically secured and electrically bonded to each other by a welding or brazing operation. For clarity of showing, the left-hand ends of the halfwindings 52 and 60 are shown as having the same dispositions in Fig. 6 as they have in Figs. 4 and 5. However, during the welding or brazing operation, the insulation-free lengths of all of
laminations 54, 56, 58, 62, 64 and 66 will be
forced into intimate face-to-face engagement so
an end view of the welded or brazed ends of the
half-windings 52 and 60 will appear to be a mass
of rectangular configuration.The winding shown
in Fig. 6 is more adaptable than is the winding 20
of Figs. 1-3 to the shop practices of a
manufacturer of motors which uses Z-bar type
windings in the armatures of D.C. motors.
Each of the windings shown in the drawing has three laminations; but the present invention can
be used with windings which have two
laminations or which have more than three
laminations. The preferred number of laminations
in a winding is in the range of three to five. Also,
although it would be possible to use more than two winding sides per slot, the ten percent to twenty percent reduction in effective resistance
noted above is attainable where just two winding sides are disposed in each slot.
The reduction in the effective resistance of the windings, which is made possible by the present invention, offers two possible savings for purchasers of electric motors. Specifically, the use of such windings would make it possible to reduce the cross section of the low resistance metal of those windings by approximately ten percent to approximately twenty percent, and hence provide a corresponding decrease in the cost of the motor. However, the more important saving for the purchaser of a motor is in the dayto-day reduction in the amount of power which
must be supplied to the motor; because low voltage, high current D.C. motors frequently operate on power from storage batteries. The reduced effective resistance of the windings, which is made possible by the present invention, enables those motors to operate for longer periods of time between recharging times.
The number of surfaces, of the windings of the present invention, which extend through the central portions of the cross sections of those windings is a function of the number of laminations in those windings. Thus, the number of those surfaces is 2(n-1) where n is the number of laminations in a winding.
Whereas the drawing and accompanyung description have shown and described two preferred embodiments of the present invention, it should be apparent to those skilled in the art that various changes may be made in the form of the invention without affecting the scope thereof.
Claims (14)
1. An electric machine wherein the armature windings comprises a plurality of preformed hairpin-like members each having spaced apart limbs joined together at one end and to respective spaced part commutator segments at the other end, the limbs being accommodated in respective coil slots of the armature and, at least in the portions thereof which are disposed within the slots, comprising a plurality of electrically insulated laminations of electrically conductive material disposed in close abutting relationship with one another.
2. A hairpin-like winding, for the armature of a relatively low voltage, relatively high current D.C.
motor wherein each coil slot in that armature accommodates just one side of each of a plurality of hairpin-like windings, that comprises an elongated lamination of low resistance metal which has one end thereof mechanically secured and electrically bonded to one segment of the commutator of said armature and which has the other end thereof mechanically secured and electrically bonded to a circumferentiallydisplaced second segment of said commutator, insulation on those portions of said lamination which constitute coil sides and which are disposed within coil slots in said armature, a second elongated lamination of low resistance metal which has one end thereof mechanically secured and electrically bonded to said one end of the first said lamination and also to said one segment of said commutator and which has the other end thereof mechanically secured and electrically bonded to said other end of said first said lamination and also to said second segment of said commutator, insulation on those portions of said second lamination which constitute coil sides and which are disposed within said coil slots in said armature, the insulation on said portions of the first said and said second laminations being in abutting relation within said coil slots, said first said and said second laminations providing surfaces for said winding which pass through portions of the cross section of said winding that correspond to the central area of the cross section of an essentially-identical winding of unitary cross section, and the current densities adjacent said surfaces enabling said winding to have a distribution of current densities across the cross section thereof which is more uniform than the distribution of current densities across the cross section of said essentially-identical winding where said essentially-identical winding has the same total cross sectional area of low resistance metal disposed in comparable fashion in a comparable armature for a comparable D.C.
motor.
3. A hairpin-like winding as claimed in claim 2 wherein the number of said surfaces is 2(n-1) where n is the number of laminations in said winding.
4. A hairpin-like winding as claimed in claim 2 or 3 wherein the number of laminations of said winding is in the range of three through five.
5. A hairpin-like winding as claimed in claim 2 or 3 or 4 wherein each of said laminations is a continuous length of insulated metal.
6. A hairpin-like winding as claimed in claim 2 or 3 or 4 wherein said winding comprises two Zbars which have adjacent ends thereof mechanically secured and electrically bonded to form said hairpin-like winding.
7. A hairpin-like winding as claimed in any of claims 2 to 6 wherein the depth of said winding is just a few thousandths of an inch greater than the depth of an essentially-identical unitary winding that has the same width and the same cross sectional area of low resistance metal.
8. A hairpin-like winding as claimed in any of claims 2 to 7 wherein a further hairpin-like laminated winding has one side thereof disposed within the coil slot in which one side of the first said hairpin-like winding is disposed, and wherein said one side of said further hairpin-like laminated winding abuts, but is disposed radially outwardly of, said one side of said first said hairpin-like winding.
9. A hairpin-like laminated winding, for the armature of a D.C. motor, that is elongated and that has one side thereof disposed in one coil slot of the armature of said motor and that has the other side thereof disposed in a circumferentiallydisplaced second coil slot of said armature, one lamination of said laminated winding being elongated and being of low resistance metal and having one end thereof mechanically secured and electrically bonded to one segment of the commutator of said armature and having the other end thereof mechanically secured and electrically bonded to a circumferentiallydisplaced second segment of said commutator, said one lamination having insulation on those portions thereof which are disposed within said one coil slot and said circumferentially-displaced second coil slot, a second lamination of said laminated winding being elongated and being of low resistance metal and having one end thereof mechanically secured and electrically bonded to said one segment of said commutator and having the other end thereof mechanically secured and electrically bonded to said circumferentially displaced second segment of said commutator, said second lamination having insulation on those portions thereof which are disposed within said one coil slot and said circumferentially-displaced second coil slot, the insulation on said portions of said one and said second laminations being in abutting relation within said coil slots, said laminated winding having the confronting surfaces of said one and said second laminations passing through portions of the cross section thereof that correspond to the central area of the cross section of an essentially-identical winding of unitary cross section, and the current densities adjacent said confronting surfaces enabling said laminated winding to have a distribution of current densities across the cross section thereof which is more uniform than the distribution of current densities across the cross section of said essentially-identical winding where said essentiaily-identical winding has the same total cross sectional area of low resistance metal disposed in comparable fashion in a comparable armature for a comparable D.C. motor.
10. A hairpin-like laminated winding as claimed in claim 9 wherein the number of said abutting surfaces is 2(n-1) where n is the number of laminations in said laminated winding.
1 A hairpin-like laminated winding as claimed in claim 9 or 10 wherein the number of laminations of said laminated winding is in the range of three through five.
12. A hairpin-like laminated winding as claimed in claim 9 or 10 or 11 wherein each of said laminations is a continuous iength of insulated metal.
1 3. A hairpin-like laminated winding as claimed in claim 9 or 10 or 1 wherein said laminated winding comprises two laminated Zbars which have adjacent ends thereof mechanically secured and electrically bonded together to form said hairpin-like laminated winding.
14. A hairpin-like laminated winding as claimed in any of claims 9 to 13 wherein the depth of said laminated winding is just a few thousandths of an inch greater than the depth of an essentially-identical unitary winding that has the same width and the same cross sectional area of low resistance metal.
1 5. A hairpin-like laminated winding as claimed in any of claims 9 to 14 wherein a further hairpin-like laminated winding has one side thereof disposed within said one coil slot, and wherein said one side of said further hairpin-like laminated winding abuts, but is disposed radially outwardly of, said one side of the first said laminated winding.
1 6. A hairpin-like winding, substantially as herein described with reference to any of the accompanying drawings, for a D.C. electric motor.
1 7. An electric motor incorporating windings as claimed in any of claims 2 to 16.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US94203978A | 1978-09-13 | 1978-09-13 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB2030375A true GB2030375A (en) | 1980-04-02 |
Family
ID=25477491
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB7928908A Withdrawn GB2030375A (en) | 1978-09-13 | 1979-08-20 | Laminated Winding in D.C. Motor |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2030375A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2263653A (en) * | 1992-02-03 | 1993-08-04 | Gen Electric | Making armatures for electrodynamic machines |
| FR3099284A1 (en) | 2019-07-26 | 2021-01-29 | Nidec Psa Emotors | Multi-stranded conductor with follower |
-
1979
- 1979-08-20 GB GB7928908A patent/GB2030375A/en not_active Withdrawn
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2263653A (en) * | 1992-02-03 | 1993-08-04 | Gen Electric | Making armatures for electrodynamic machines |
| US5363546A (en) * | 1992-02-03 | 1994-11-15 | General Electric Company | Apparatus for making armatures for electrodynamic machines |
| GB2263653B (en) * | 1992-02-03 | 1996-03-06 | Gen Electric | Making armatures for electrodynamic machines |
| FR3099284A1 (en) | 2019-07-26 | 2021-01-29 | Nidec Psa Emotors | Multi-stranded conductor with follower |
| WO2021019158A1 (en) | 2019-07-26 | 2021-02-04 | Nidec Psa Emotors | Stranded conductor with adhesive |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |