GB2491573A - Two part stator for an electrical machine - Google Patents
Two part stator for an electrical machine Download PDFInfo
- Publication number
- GB2491573A GB2491573A GB201109184A GB201109184A GB2491573A GB 2491573 A GB2491573 A GB 2491573A GB 201109184 A GB201109184 A GB 201109184A GB 201109184 A GB201109184 A GB 201109184A GB 2491573 A GB2491573 A GB 2491573A
- Authority
- GB
- United Kingdom
- Prior art keywords
- stator
- component
- slots
- stator component
- windings
- 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- Withdrawn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
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K1/00—Details of the magnetic circuit
- H02K1/06—Details of the magnetic circuit characterised by the shape, form or construction
- H02K1/12—Stationary parts of the magnetic circuit
- H02K1/14—Stator cores with salient poles
- H02K1/146—Stator cores with salient poles consisting of a generally annular yoke with salient poles
- H02K1/148—Sectional cores
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K1/00—Details of the magnetic circuit
- H02K1/06—Details of the magnetic circuit characterised by the shape, form or construction
- H02K1/12—Stationary parts of the magnetic circuit
- H02K1/16—Stator cores with slots for windings
- H02K1/165—Shape, form or location of the slots
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K1/00—Details of the magnetic circuit
- H02K1/06—Details of the magnetic circuit characterised by the shape, form or construction
- H02K1/22—Rotating parts of the magnetic circuit
- H02K1/27—Rotor cores with permanent magnets
- H02K1/2706—Inner rotors
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K2201/00—Specific aspects not provided for in the other groups of this subclass relating to the magnetic circuits
- H02K2201/03—Machines characterised by aspects of the air-gap between rotor and stator
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Iron Core Of Rotating Electric Machines (AREA)
Abstract
A stator comprises an inner stator component 10 comprising an annular base portion 12 and a plurality of teeth 14 extending radially outwards and defining slots for stator windings 24. An outer stator component 20, which may form a back iron, is arranged to surround the inner stator component 10. The stator is assembled by first inserting the stator windings into the slots in the inner stator component, and then inserting the inner stator component with the stator windings in place into the outer stator component. The teeth of the inner stator may engage slots in the outer stator to prevent relative rotation between the stator parts. The windings may be preformed and comprise concentrated or distributed windings. The teeth may have parallel or divergent sides and may extend at an angle to the radius and may be straight or curved.
Description
STATOR FOR AN ELECTRICAL MACHINE
The present invention relates to a stator for a rotating electrical machine such as a motor or generator.
S
Rotating electrical machines comprise a stator, and a rotor arranged to rotate relative to the stator. The rotor is provided with rotor windings or permanent magnets in order to develop a magnetic flux in the air gap between the rotor and the stator. The stator is provided with stator windings which intersect the magnetic flux. In the case of a 0 generator, when the rotor is rotated by a prime mover, the rotating magnetic field results in an electrical current flowing in the stator windings, thereby generating the electrical output. In the case of a motor, an electrical current is supplied to the stator windings and the thus generated magnetic field causes the rotor to rotate.
Known stators comprise a generally cylindrical back iron with a number of teeth extending radially inwards, the teeth defining a plurality of slots for accommodating the stator windings. During manufacture, the stator windings may be wound into the slots in situ, or else preformed coils may be slid onto the teeth. However, in either case, insert in.g the stator windings into the slots may be cumbersome, and it may be difficult to achieve the desired winding density.
WO 01/95459 discloses a technique for facilitating the insertion of stator windings into slots in a stator. The stator comprises a core which is made up of a series of connected segments that are rotatable relative to one another during assembly of the machine. Each segment includes a base portion and a pole piece which projects inwards in an arc.
During assembly, the stator is opened up to allow coils to be fitted to the pole pieces. The stator is then closed to form an annular statc.r, This arrangement can allow the coils to be fitted more readily. However, the stator arrangement is more complex, and the strength of the stator may be compromised.
According to the present invention there is provided a stator for an electrical machine, the stator comprising: an inner stator component comprising an annular base portion and a plurality of teeth extending radially outwards and defining slots for stator windi.ngs, and an outer stator component arranged to surround the inner stator component.
The present invention may provide the advantage that, by providing an inner stator component with a plurality of teeth extending radially outwards, the stator windings may S be inserted onto the slots from the outside. This is in contrast to conventional stators where the windings are inserted from the inside. The present invention may therefore allow the winding insertion time to be reduced, and may simpli the machine assembly process.
The annular base portion preferably has an inner surface which is arranged to face an air gap between the stator and a rotor. Preferably, the annular base portion has a generally cylindrical inner surface, which can allow a rotor to rotate inside the stator.
The annular base portion may have an inner surface which is substantially continuous.
IS This may help to reduce windage losses, by allowing a smooth surface to be presented to the air gap.
Conventional stators for electrical machines have an open slot design. in which the slots are open to the air gap between the rotor and the stator. However the present inventors have realised that by careful stator design, it may be possible to close the slots. Thus, the slots may be at least partially closed on the radially innermost side of the inner stator component, and preferably completely closed. This can facilitate an arrangement in which the teeth extend radially outwards, and can help to ensure that the annular base portion has sufficient strength. Furthermore, by closing the slots to the air gap, the fault tolerance of the machine may be improved, and the machine may require lower maintenance. This may be particularly advantageous in applications such as wind turbines where the machine may be subject to high stresses and may be difficult to reach.
Alternatively, if desired, at least some of the slots may be partially open through the inner surface of the annular base portion. In some circumstances this arrangement may be preferred in order to give the desired magnetic flux in the air gap.
Preferably the machine is assembled by first inserting the stator windings into the slots on the inner stator component, and then inserting the inner stator component with the stator windings in place into the outer stator component. Thus the inner stator component may be removable from the outer stator component This may facilitate insertion of the windings into the slots.
For example, the outer stator component may be arranged to be slid over the inner stator component axially. As an alternative, the outer stator component may have a hinged arrangement such as that described in WO 01/95459, and may be closed up around the inner stator component, or any other arrangement may be used which allows the outer stator component to be placed around the inner stator component.
Preferably the inner stator component and the outer stator component are arranged to interlock to prevent rotation between the two, when the inner stator component is inserted into the outer stator component. This may help to ensure the structural integrity of the assembled stator, For example, the inner surface of the outer stator component may comprise at least one recess or projection which matches a corresponding projection or recess on the inner stator component. As an example, the inner surface of the outer stator component may comprise a plurality of axial slots arranged to accommodate the outermost ends of the teeth. This can allow the inner stator component to be skd into the outer stator component axially, while preventing relative rotation between the two.
Preferably the outer stawr component is arranged to retain the stator windings in the slots.
For example, the outer stator component may be arranged to close the slots at their radially outermost sides when the inner stator component is inserted into the outer stator component. The outer stator component may also be arranged to give structural support to the stator assembly. Preferably the outer stator component is an annular back iron, In its assembled state, the stator may further comprise stator windings around the teeth.
The stator winding are preferably preformed coils. This may faciRtate insertion of the wind ings into the slots. Each coil may be mounted on a carrier, such as a bobbin.
Alternatively, the stator windings may be wound in situ.
Preferably the coils are arranged to substantially fill the slots in the assembled machina The stator windings may be concentrated, non-overlapping wind ings. This may help to maximise the poIer density of the machine, due to the shorter winding length and lower resistance. Furthermore, this arrangement may allow a higher slot-fill factor to be achieved. However distributed and/or overlapping windings may be used if desired.
The Inner stator component may have any appropriate number of teeth, depending in part on the number of phases and the number olpoles. While the teeth extend radially outwards, they may be at an angle to the radius of the machine, and may be straight or curved. The sides of the teeth may be parallel, or they may diverge as they project from the annular base portion, for exam pie so as to define substantially rectangular slots.
According to another aspect of the invention there is provided a rotating electrical machine comprising a stator in any of the forms defined above, and a rotor arranged to rotate inside the stator, The machine may be single phase, three phase, or any other number of phases, and may have any appropriate number of poles.
According to another aspect of the invention there is provided a method of winding a stator for an electrical machine, the method comprising: inserting windings into slots in an inner stator component, the inner stator component comprising an annular base portion and a plurality of teeth extending radially outwards and defining the slots: and inserting the inner stator component and stator windings into an outer stator component arranged to surround the inner stator component Features of one aspect of the invention may be applied to any other aspect. Apparatus features may be provided as method features and vice versa.
Preferced features of the present invention will now be described, purely by way of the example, with reference to the accompanying drawings, in which: Figure 1 shows a radial cross-section through a conventional stator; Figure 2 shows a radial cross section through an inner stator component in an embodiment of the present invention; and Figure 3 shows parts of an assembled stator.
Figure 1 shows a radial cross-section through a conventional stator for an electrical machine. The stator comprises a back iron 2, with a plurality of teeth 4 extending radially inwards. The teeth 4 define a plurality of sLots 6 for accommodating stator windings.
S During manufacture, the stator windings are inserted into the slots from the inside of the stator.
Figure 2 shows a radial cross section through an inner stator component in an embodiment of the present invention. Referring to Figure 2, the inner stator component 10 comprises an annular base portion 12 and a plurality of radial teeth 14. The annular base portion 12 is located on the radially in:nermost side. The teeth 14 extend radiafly outwards from the base portion 12, and define a plurality of slots 16 for accommodating stator windings. As can be seen from Figure 2, the slots 16 are open at their radially outermost side.
IS
During manufacture, stator wind ings in the form of pre-formed coils are pushed onto the teeth 14. Since the coils can be pushed onto the teeth from the outside, it is relatively simple to assemble the stator wind ings. Once the coils have been inserted., a back iron is put in place around the inner stator component Figure 3 shows parts of an assembled stator in an embodiment of the invention. The stator comprises inner stator component 10, back iron (outer stator component) 20, and stator coil 24. The stator is formed by sliding the back iron 20 over the inner stator component 10 with the stator windings in place. In Figure 3 a single coil 24 is shown, in order to avoid obscuring the inner stator component. However in practice a coil is provided over each of the teeth 14. In this embodiment the coils are pre-wound concentrated, non-overlapping type windings, The back iron 20 retains the stator windings and provides strength to the overail assembly.
The back iron 20 has axial slots 22 on its inner surface which accommodate the ends of the teeth 14. The slots allow the back iron to be slid axially over the inner stator component.
In the assembled stator, the slots prevent rotation of the inner stator component within the back iron.
The techniques described above can reduce the winding insertion time and simpkiy the whole machine assembly process.
It will be appreciated that, in contrast to conventional stator designs, the stator of the S present invention has a closed slot design in which the slots 16 are closed on the radially innermost side. The extent to which the slots can be closed depends largely on the amount of flux leakage which is acceptable. In general, closing the slots increases the flux leakage, which is an undesirable effect. For closed slots, a thicker bridge results in a more robust rotor structure, but also a higher flux leakage. Thus the closed slots need to be tailored carefully to ensure an acceptable leakage flux on the one hand, and sufficient rotor strength on the other.
The inner stator component 10 and the back iron 20 may be manufactured from laminated steel or any other suitable material using known manufacturing techniques.
While Figures 2 and 3 show a total of nine teeth, in practice any number of teeth may be provided, depending on the number of poles and the number of phases of the electrical machine.
In the embodiment described above, the coils are concentrated-wound, non-overlapping windings, which offer advantages in terms of maximising the power density of the machine and lowering copper losses due to the shorter end-winding length. This winding arrangement may also allow a higher slot fill factor to be achieved. However other winding arrangements could be. used instead, and the windings could be wound in situ.
Claims (14)
- CLAIMS1. A stator for an electrical machine, the stator comprising: an inner stator component comprising an annular base portion and a plurality of teeth extending radially outwards and defining slots for stator windings; and an outer stator component arranged to surround the inner stator component.
- 2. A stator according to claim I, wherein the annular base portion has an inner surface which is arranged to face an air gap between the stator and a rotor.
- 3, A stator according to claim I or 2, wherein the annular base portion has a generally cylindrical inner surface.
- 4, A stator according to any of the preceding claims, wherein the annular base portion has an inner surface which is substantially continuous.
- S. A stator according to any of the preceding claims, wherein the slots are at least partially closed on the radiafls' innermost side.
- 6. A stator according to any of the preceding claims, wherein the slots are closed on the radially innermost side.
- 7. A stator according to any of the preceding claims wherein the inner stator component is removable from the outer stator component.
- 8. A stator according to any of the preceding claims wherein the outer stator component is arranged to be slid over the inner stator component axially.
- 9, A stator according to any of the preceding claims, wherein the inner stator component and the outer stator component are arranged to interlock to prevent rotation between the two.
- 10. A stator according to any of the preceding claims, wherein the inner surface of the outer stator component comprises at feast one recess or projection which corresponds to a projection or a recess on the inner stator component.
- ii. A stator according to any of the preceding claims, wherein the inner surface of the outer stator component comprises a plurality of axial slots arranged to accommodate the outermost ends of the teeth.
- 12. A stator according to any of the preceding claims, wherein outer stator component is arranged to retain the statorwindings in the slots.
- 13. A stator according to any of the preceding claims, wherein the outer stator component is arranged to close the slots at their radially outermost sides when the inner stator component is inserted into the outer stator component
- 14. A stator according to any of the preceding claims, wherein the outer stator component is arranged to give structural support to the stator assembly.15.. A stator according to any of the preceding claims., wherein the outer stator component is an annular back iron.16. A stator according to any of the preceding claims, further comprising stator windings in the slots.17.. A stator according to claim 16 wherein the stator windings are preformed coils.18. A stator according to claim 16 or I 7. wherein the stator windings are concentrated, nonoverlapping windings.$0 19. A rotating electrical machine comprising a stator according to any of the preceding claims, and a rotor arranged to rotate inside the stator.20. A method of winding a stator for an electrical machine, the method comprising: inserting windings into slots in an inner stator component, the inner stator component comprising an annular base portion and a plurality 0 teeth extending radially outwards and defining the slots, and inserting the inner stator component and stator windings into an outer stator S component arranged to surround the inner stator component.21. A stator substantially as described herein with reference to and as illustrated in the accompanying drawings.22. A method of winding a stator for an electrical machine substantially as described herein with reference to the accompanying drawings.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB201109184A GB2491573A (en) | 2011-05-31 | 2011-05-31 | Two part stator for an electrical machine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB201109184A GB2491573A (en) | 2011-05-31 | 2011-05-31 | Two part stator for an electrical machine |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB201109184D0 GB201109184D0 (en) | 2011-07-13 |
| GB2491573A true GB2491573A (en) | 2012-12-12 |
Family
ID=44310705
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB201109184A Withdrawn GB2491573A (en) | 2011-05-31 | 2011-05-31 | Two part stator for an electrical machine |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2491573A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR3019948A1 (en) * | 2014-04-10 | 2015-10-16 | Leroy Somer Moteurs | ROTOR OF ELECTRIC ROTATING MACHINE. |
| EP3007319A4 (en) * | 2013-05-28 | 2017-03-22 | Mitsubishi Electric Corporation | Rotary electric machine, and manufacturing method therefor |
| EP3337012A1 (en) * | 2016-12-13 | 2018-06-20 | Hyundai Motor Company | Rotor structure of a wound rotor synchronous motor |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2391395A (en) * | 2002-07-25 | 2004-02-04 | Dana Automotive Ltd | Method of making a stator for a motor |
| GB2394123A (en) * | 2002-08-05 | 2004-04-14 | Visteon Global Tech Inc | Stator for brushless motor |
| US20040183393A1 (en) * | 2003-03-18 | 2004-09-23 | Asmo Co., Ltd. | Stator for dynamo-electric machine |
| US20050012413A1 (en) * | 2003-05-30 | 2005-01-20 | Siemens Aktiengesellschaft | Electric machine with improved contacting feature |
| EP1959542A2 (en) * | 2007-02-13 | 2008-08-20 | Sanyo Denki Co., Ltd. | Stator for motor |
-
2011
- 2011-05-31 GB GB201109184A patent/GB2491573A/en not_active Withdrawn
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2391395A (en) * | 2002-07-25 | 2004-02-04 | Dana Automotive Ltd | Method of making a stator for a motor |
| GB2394123A (en) * | 2002-08-05 | 2004-04-14 | Visteon Global Tech Inc | Stator for brushless motor |
| US20040183393A1 (en) * | 2003-03-18 | 2004-09-23 | Asmo Co., Ltd. | Stator for dynamo-electric machine |
| US20050012413A1 (en) * | 2003-05-30 | 2005-01-20 | Siemens Aktiengesellschaft | Electric machine with improved contacting feature |
| EP1959542A2 (en) * | 2007-02-13 | 2008-08-20 | Sanyo Denki Co., Ltd. | Stator for motor |
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP3007319A4 (en) * | 2013-05-28 | 2017-03-22 | Mitsubishi Electric Corporation | Rotary electric machine, and manufacturing method therefor |
| US9923438B2 (en) | 2013-05-28 | 2018-03-20 | Mitsubishi Electric Corporation | Method for manufacturing a rotary electric machine |
| FR3019948A1 (en) * | 2014-04-10 | 2015-10-16 | Leroy Somer Moteurs | ROTOR OF ELECTRIC ROTATING MACHINE. |
| WO2015155731A3 (en) * | 2014-04-10 | 2015-12-23 | Moteurs Leroy-Somer | Rotor for a rotary electric machine |
| CN106165261A (en) * | 2014-04-10 | 2016-11-23 | 利莱森玛电机公司 | Rotor for electric rotating machine |
| US10432049B2 (en) | 2014-04-10 | 2019-10-01 | Moteurs Leroy-Somer | Rotor for a rotary electric machine |
| CN106165261B (en) * | 2014-04-10 | 2020-03-20 | 利莱森玛电机公司 | Rotor for rotating electric machine |
| EP3337012A1 (en) * | 2016-12-13 | 2018-06-20 | Hyundai Motor Company | Rotor structure of a wound rotor synchronous motor |
| CN108616176A (en) * | 2016-12-13 | 2018-10-02 | 现代自动车株式会社 | The rotor structure of WRSM motor |
| US10476331B2 (en) | 2016-12-13 | 2019-11-12 | Hyundai Motor Company | Rotor structure of WRSM motor |
| CN108616176B (en) * | 2016-12-13 | 2021-02-19 | 现代自动车株式会社 | Rotor structure of wound rotor driving motor |
Also Published As
| Publication number | Publication date |
|---|---|
| GB201109184D0 (en) | 2011-07-13 |
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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) |