GB2239128A - Noise reduction in air cooled induction rotary electric machine - Google Patents
Noise reduction in air cooled induction rotary electric machine Download PDFInfo
- Publication number
- GB2239128A GB2239128A GB9023455A GB9023455A GB2239128A GB 2239128 A GB2239128 A GB 2239128A GB 9023455 A GB9023455 A GB 9023455A GB 9023455 A GB9023455 A GB 9023455A GB 2239128 A GB2239128 A GB 2239128A
- Authority
- GB
- United Kingdom
- Prior art keywords
- rotor
- stator
- gaps
- rotary electric
- electric machine
- 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.)
- Granted
Links
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
- H02K3/24—Windings characterised by the conductor shape, form or construction, e.g. with bar conductors with channels or ducts for cooling medium between the conductors
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K9/00—Arrangements for cooling or ventilating
Abstract
The stator coil conductors 2 have a plurality of stator coil ends (13) substantially axially extending from the stator core 1 to define therebetween substantially radially extending stator gaps (22). The rotor coil conductors 7 have a plurality of rotor coil ends (14) substantially axially extending from the rotor core and define therebetween substantially radially extending rotor gaps (21). The closure member formed by a noise reduction ring circumferentially extending between the stator and the rotor gaps is disposed between the stator coil ends (13) and the rotor coil ends (14) for substantially blocking direct fluid communication between the stator and the rotor gaps (21, 22). The closure member may be a noise reduction ring surrounding the rotary bar ends and having a width sufficient for deflecting the cooling air flow radially flowing through the rotor radial gaps away from a straight portion of the stator coils or a width sufficient for substantially closing the radial gaps or alternatively filler material disposed within the stator gaps or the rotor gaps. <IMAGE>
Description
INDUCTION ROTARY ELECTRIC MACHINE
BACKGROUND OF THE INVENTION
This invention relates to an induction rotary electric machine and, more particularly, to an induction rotary electric machine in which wind noise is decreased.
Figs. 9 to 11 illustrate one example of the conventional induction rotary electric machine disclosed in a brochure A-C6785-C "Mitsubishi Vehicular Drive Induction
Motor" published by Mitsubishi Denki Kabushiki Kaisha, for example.
In these figures, reference numeral 1 is a stator, 2 is a stator coil secured to the stator 1, 3 is a rotor, 4 is a rotor shaft of the rotor 3, 5 are bearings for the rotary shaft 4, 6 are ventilation holes formed in the rotor 3, 7 are rotor bars secured to the rotor 3, 8 is a cooling fan for self-cooling ventilation, 9 are inlet openings for introducing coolIng air, ,O are cutlet openIngs for exhausting the cooling air, 11 are arrows indicating the air flow, 12 are gap defined between the stator 1 and the rotor 3, 13 are stator coil ends, 14 are rotor bar ends, and 15 are straight portions of the stator coil ends 13 projecting from the stator 1.
The operation of the cooling air in-the above conventional arrangement will now be described.
As the induction motor rotates, the rotor 3 generates flows of cooling air, which flow through the following four flow paths.
The first is a flow path extending from the intake openings 9 directly leading to the gaps 12 and flowing to the exhaust openings 10 through the cooling fan 8.
The second flow path extends from the intake openings 9 to the exhaust openings 10 through the ventilation holes 6 on the intake side of the rotor 3 the gaps between the rotor bar ends 14 cn the intake side of the rotor - the gaps 12 < the stator coil ends 12 ) the gaps 12 b the cooling fan.
The third path extends from the intake holes 9 to the exhaust holes 10 through the ventilation holes 16 on the exhaust side of the rotor 3 i the gaps between the rotor bar ends 14 on the exhaust side of the rotor ^ the gaps 12 - the stator coil ends 13 - the cooling fan.
The fourth flow path is the path extending from the intake holes 9 to the exhaust holes 10 through the ventilation holes 6 of the rotor directly by the cooling fan 8.
Thus, the cooling air flows through the cooling fan 8 from the exhaust holes 10 after it is divided into four parts.
In the conventional induction rotary machine, cooling air flows from the gaps 21 between the rotor bar ends 14 to flow through the gaps 12 to impinge at the stator coil ends 13 and particularly at the straight portion 15 thereof and then into the gaps 22 between the stator coil ends 13.
On the other hand, -Ince the stator coil ends 13 opposing to the gaps 21 between the stator bar ends 14 are positioned alternatively with the gaps 22 between the stator coil ends 13, the cooling air generates an air oscillation at a frequency of "number of gaps between the rotor bar ends number of rotation / 50", which generates noise.
The conventional arrangement, in which a part of the noise is generated by the above-discussed cooling air flow, has a problem that this noise should be decreased.
SUMMARY OF THE INVENTION
Accordingly, one obejct of the present invention is to provide an induction rotary machine free from the abovediscussed problems of the conventional induction rotary machine.
Another object cf the present ivnention is to provide an induction rotary machine in which noise due to the flow of cooling air is reduced.
A further object of the present invention is to provide an induction rotary machine in which oscillation of the cooling air is eliminated.
According to the induction rotary electric machine of the first invention, a closure member is provided for closing a gap between rotor bar ends of rotor bars mounted to a rotor of an induction rotary electric machine at the rotorside thereof on the side of the rotary bar end opposite to a stator, and according to the second invention, the induction rotary electric machine is provided with a closure member closing a gap between stator coil ends of stator coil mounted to a stator of an induction rotary electric machine at the straight portion of the stator coil ends on the side of the stator coil ends opposite to a rotor.
According to the induction rotary electric machine, the closure member disposed at the rotor bar ends or the closure member disposed at the stator coil ends interrupt the cooling air flow flowing frcm the gaps between the rotor bar ends, so that it does not impinge upon the stator coil ends and particularly to its straight portion and smoothly flows toward the exhaust openings without generating "number of the gaps between the rotator bar ends > number of rotation / 60", resulting in the reduction of the noise of the frequency at this frequency component.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will become more readily apparent from the following detailed description of the presferred embodiments of the present invention taken in conjunction with the accompanying drawings, in which:
Fig. 1 is a longitudinal sectional view of the induction electric motor of one embodiment of the first invention of the present invention;
Fig. 2 is a partial enlarged sectional view of the stator coil end portion illustrated in Fig. 1;
Fig. 3 is a side view of Fig. 2;
Fig. 4 is an explanatory view of the stator coil ends as viewed from the above in Fig. 2;
Fig. 5 is a longitudinal sectional view of another embodiment of the first invention;
Fig. 6 is a longitudinal sectional view of the induction motor of the second invention of the present invention;;
Fig. 7 is a partial enlarged sectional view of the stator coil end portion illustrated in Fig. 6;
Fig. S is a side view of Fig. 7;
Fig. 9 is a longitudinal sectional view of the conventional induction motor; Fia. 10 is a n,-r+5 al anl arced sectional view of the coil end portion illustrated in Fig. 9; and
Fig. 11 is a side view of Fig. 10.
Throughout the figures, the same reference numerals designate identical or corresponding components.
DESCRIPTION OF THE PREFERRED EMBODIEMNTS
The present invention will now be described in conjunction with the drawings illustrating one embodiment thereof.
Those components designated by the same reference numerals as those of the conventional arrangement are those identical or corresponding to the components designated by the reference numerals used in the conventional arrangement.
In Figs. 1 to 4 illustrating one embodiment of the first invention, reference numeral 31 is a noise-reduction ring which is a closure member closing the gap between the rotor bar ends 14 disposed on the side of the rotor 3 and the side opposite to the stator 1 of the rotor bar ends 14. Since the induction rotary machine of the first invention which is the vehicular induction motor is as above, the cooling air flow generated by the centrifugal force due to the rotation of the rotor 3 flows as descrIbed bellow.
That is, the cooling air flow introduced into the intake openings 9 flows through the ventilation holes 6 and is exhausted from the exhaust openings 10, while the cooling air flow generated by the centrifugal force flows out from the gaps 21 between the rotor bar ends 14 of the rotor bar ends 14 remote from the rotor 3 to enter into the gaps 12 to flow into the exhaust openings 10 directly from the gaps 12 or through the end portion side of the stator coil ends 13.
Therefore, although the cooling air flow generated by the above centrIfugal force in the conventional arrangement has impinged upon the projected and the recessed portions of the stator coil ends 13 on the stator side and the gaps 22 between the stator coil ends t 3 and generated noise of a frequency of "number of gaps between the rotor bar ends number of rotation / 60", the cooling air flow in the present invention does not impinge upon the stator coil ends partIcularly upon its straight portion 15 on the side of the stator 1 which contributes most to the generation of the noise, allowing the cooling air to flow smoothly.Also since the stator coil ends 13 are tilted radially outwardly as they axially outwardly extend first the straight potion 15 at both of the exhaust and intake sides, the recessed and the projected portions have a skewed configuration and not straight as in the straight portion 15, so that the cooling air impinges evenly to allow the cooling air to flow smoothly, making less contribution to the generation of noise. Thus, the cooling air flow due to the centrifugal force of the rotor 3 is made dislocated from the straight portion 15.
According to an experiment of this embodiment, it has been confirmed that the noise of the above frequency is decreased by about 10 dB(C) from about 104 dB(C) to about 94 dB(C).
While the noise reduction ring 31 is disposed at one portion of the rotor bar ends 1 4 on the side of the rotor 1 in the above embodiment, a noise reduction ring 32 extending over the entire width may be provided for preventing the cooling air flow due to the centrifugal force from flowing into the rotor bar ends 14 as illustrated in Fig. 5.
Also, while the noise reduction rings 31 and 32 are provided to outwardly encircle the stator coil ends 13 in the above embodiment, the gaps 21 between the rotor bar ends 14 may be closed with a filling material as a closure member in place of the noise reduction rings 31 and 32 for changing the flow path of the cooling air.
Further, the filling material may be disposed in the gaps 21 between the rotor bar ends 14 at random, thereby making the frequency of the noise generating source irregular or at uneven pitch.
In Figs. 6 to 8 illustratIng one embodiment of the second invention of the present invention, reference numeral 41 is a noise-reduction ring which is a closure member closing çl.e gaps between the stator coil ends 13 disposed on the side of the stator 1 and the side opposite to the rotor 3 of the stator coil ends 13.
Since the embodiment of the second invention is constructed as above described, the cooling air flow generated by the centrifugal force due to the rotation of the rotor 3 flows as described bellow.
That is, while the cooling air flow generated by the centrifugal force is introduced into the gaps 21 between the rotor bar ends 14 from the intake-side ventilation holes of the rotor 3 on the intake side1 since the noise reduction ring 41 is provided in this portion, the cooling air flow is not allowed to enter into the gaps 22 between the stator coil ends 13 and only flows through the gaps 12 until it reaches the exhaust side where it IS exhausted from the exhaust openings 10 through the cooling fan 8.
Although the cooling air flow at the exhaust side is introduced into the gaps 12 from the ventilation holes on the exhaust side through the gaps 21 between the rotor bar ends 14, the flow is not allowed to enter into the gaps 22 on the stator side between the stator coil ends 13 due to the noise reduction gear but flows to the exhaust side directly or through space between the end portions of the stator coil ends, where it flows in the same path as that of the intake side.
Therefore, even when the cooling air flow generated by the above centrifugal force impinges upon the smooth noise reduction ring 41, it is not permitted to enter into the gaps 22 between the stator ccil ends 43 and no oscillation of a frequency of "number of gaps between the rotor bar ends number of rotation / 60" is generated due to the smooth configuration of the noise reduction ring 41, whereby the noise caused by the oscillation can be reduced.
Also, according to an experiment of this embodiment, a reduction of about 10 dB(C) which is similar to that in the case of the first invention was obtained.
While the noise reduction ring 41 is disposed at the stator coil ends 13 on the side of the rotor 1 in the above embodiment, the gaps 22 between the stator coil ends 13 may be provided with a filling material to remove the recessed and the projecting portions between the stator coil ends to provide a smooth surface, or alternatively, the filling material may be disposed at random.
Further, while the first and the second inventions have been described in terms of an induction motor for vehicles, the present invention is not limited thereto, but can be applied to an Induction generator and induction rotary electric machine for use In other than vehicles with advantages similar to those of the embodiments of the present invention.
As has been described according to the present invention, an induction rotary machine is obtained, in which the gaps between the rotor bar ends on the side opposite to the stator are closed in the first invention, and a closure member for closing gaps between stator coil ends on the rotor side of the stator coil ends, so that the cooling air flow generated by the centrifugal force of the rotor does not impinge upon the stator coil ends on the stator side and the gaps therebetween and, therefore, this portion generates no air oscillation, whereby the noise resulting from the oscillation is reduced.
Claims (9)
1. An induction rotary electric machine comprising:
a stator having a stator core and a plurality of stator coil conductors disposed in said stator core, said stator coil conductors having a plurality of stator coil ends substantially axially extending from said stator core and defining therebetween substantially radially extending stator gaps;
a rotor having a rotor core rotatably supported within said stator and a plurality of rotor coil conductors disposed in said rotor core, said rotor coil conductors having a plurlaity of rotor coil ends substantially axially extending from said rotor core and defining therebetween substantially radially extending rotor airs: and
closure means, disposed between said stator coil ends and said rotor coil ends for substantially blocking direct fluid communication between said stator and said rotor gaps.
2. An induction rotary electric machine as claimed in claim 1, wherein said closure means comprises a noise reduction ring circumferentlally extending between said stator and said rotor gaps.
3. An induction rotary electric machine as claimed in claim 1, wherein said closure means comprises a closure member for closing radial gaps defined between rotor bar ends of rotor bars mounted to a rotor of an inductIon rotary electric machine at the rotor-side thereof on the side of the rotary bar ends opposite to a stator.
4. An inductIon rotary electric machine as claimed in claim 1, wherein said closure member comprises a noise reduction ring surrounding said rotary bar ends, said noise reduction ring having a width suffIcient for deflecting the cooling air flow radially flowing through said radial gaps between the rotor bar ends away from a straight portion of said stator coils.
5. An induction rotary electric. machiner as claimed in claim 2, wherein said noise reduction ring surrounding said rotary bar ends, said noise reduction ring having a width sufficient for substantially closing said radial gaps.
6. An induction rotary electric machine as claimed in claim 1, wherein said closure means comprises a plurality of closing members each disposed within said stator gaps between said stator coil ends.
7. An induction rotary electric machine as claimed in claim 1, wherein said closure means comprises a plurality of closing members each disposed within said rotor gaps between said rotor coil ends.
8. An induction rotary electric machine as claimed in claim 1, wherein said closure means comprises a closure member closing radial gaps defined between stator coil ends of stator coil mounted to a stator of an induction rotary electric machine at the straight portion of the stator coil ends on the side of the stator coil ends opposite to a rotor.
9. An induction rotary electric machine substantially as
herein described with reference to Figures 1 to 5 or Figures 6 to 8 of
the accompanying drawings.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP28204089A JPH03145950A (en) | 1989-10-31 | 1989-10-31 | Inductive rotating electric machine |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| GB9023455D0 GB9023455D0 (en) | 1990-12-12 |
| GB2239128A true GB2239128A (en) | 1991-06-19 |
| GB2239128B GB2239128B (en) | 1994-06-29 |
Family
ID=17647390
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB9023455A Expired - Fee Related GB2239128B (en) | 1989-10-31 | 1990-10-29 | Noise reduction in a vehicle traction motor |
Country Status (5)
| Country | Link |
|---|---|
| JP (1) | JPH03145950A (en) |
| AU (1) | AU615391B2 (en) |
| ES (1) | ES2024932A6 (en) |
| GB (1) | GB2239128B (en) |
| MX (1) | MX173991B (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AT404413B (en) * | 1992-09-02 | 1998-11-25 | Abb Daimler Benz Transp | Ac motor, in particular a squirrel-cage rotor |
| EP0903833A1 (en) * | 1997-09-18 | 1999-03-24 | Siemens Aktiengesellschaft | Electrical machine with squirrel cage rotor |
| WO2006031916A1 (en) * | 2004-09-13 | 2006-03-23 | Siemens Energy & Automation, Inc. | System and method for managing air flow in a motor |
| CN105299290A (en) * | 2014-07-03 | 2016-02-03 | 株式会社不二工机 | Electric valve |
| EP3598618A1 (en) * | 2018-07-19 | 2020-01-22 | Siemens Mobility GmbH | Dynamoelectric rotary machine with elements for reducing of tonal noise |
| CN111894910A (en) * | 2020-06-30 | 2020-11-06 | 西安中车永电捷力风能有限公司 | Noise reduction structure, fan and motor thereof |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4246503A (en) * | 1977-12-16 | 1981-01-20 | Hitachi, Ltd. | Gas flow cooling system for a rotary electric machine |
| US4546279A (en) * | 1984-05-07 | 1985-10-08 | Westinghouse Electric Corp. | Dynamoelectric machine with rotor ventilation system including exhaust coolant gas diffuser and noise baffle |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5815450A (en) * | 1981-07-16 | 1983-01-28 | Mitsubishi Electric Corp | Ventilating device for rotary electric machine |
| US4684835A (en) * | 1985-10-07 | 1987-08-04 | Ametek, Inc. | Motor cooling fan housing |
-
1989
- 1989-10-31 JP JP28204089A patent/JPH03145950A/en active Pending
-
1990
- 1990-10-25 AU AU65510/90A patent/AU615391B2/en not_active Ceased
- 1990-10-29 GB GB9023455A patent/GB2239128B/en not_active Expired - Fee Related
- 1990-10-30 MX MX2311090A patent/MX173991B/en unknown
- 1990-10-30 ES ES9002750A patent/ES2024932A6/en not_active Expired - Fee Related
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4246503A (en) * | 1977-12-16 | 1981-01-20 | Hitachi, Ltd. | Gas flow cooling system for a rotary electric machine |
| US4546279A (en) * | 1984-05-07 | 1985-10-08 | Westinghouse Electric Corp. | Dynamoelectric machine with rotor ventilation system including exhaust coolant gas diffuser and noise baffle |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AT404413B (en) * | 1992-09-02 | 1998-11-25 | Abb Daimler Benz Transp | Ac motor, in particular a squirrel-cage rotor |
| EP0903833A1 (en) * | 1997-09-18 | 1999-03-24 | Siemens Aktiengesellschaft | Electrical machine with squirrel cage rotor |
| WO2006031916A1 (en) * | 2004-09-13 | 2006-03-23 | Siemens Energy & Automation, Inc. | System and method for managing air flow in a motor |
| US7683510B2 (en) | 2004-09-13 | 2010-03-23 | Siemens Industry, Inc. | System and method for managing air flow in a motor |
| CN101053143B (en) * | 2004-09-13 | 2013-03-13 | 西门子工业公司 | System and method for managing air flow in a motor |
| CN105299290A (en) * | 2014-07-03 | 2016-02-03 | 株式会社不二工机 | Electric valve |
| EP3598618A1 (en) * | 2018-07-19 | 2020-01-22 | Siemens Mobility GmbH | Dynamoelectric rotary machine with elements for reducing of tonal noise |
| US11539275B2 (en) | 2018-07-19 | 2022-12-27 | Siemens Mobility GmbH | Dynamoelectric rotary machine with elements for reducing tonal noises |
| CN111894910A (en) * | 2020-06-30 | 2020-11-06 | 西安中车永电捷力风能有限公司 | Noise reduction structure, fan and motor thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| GB2239128B (en) | 1994-06-29 |
| AU6551090A (en) | 1991-05-09 |
| MX173991B (en) | 1994-04-13 |
| GB9023455D0 (en) | 1990-12-12 |
| AU615391B2 (en) | 1991-09-26 |
| JPH03145950A (en) | 1991-06-21 |
| ES2024932A6 (en) | 1992-03-01 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| 746 | Register noted 'licences of right' (sect. 46/1977) |
Effective date: 19951107 |
|
| PCNP | Patent ceased through non-payment of renewal fee |
Effective date: 19961029 |