WO1997045917A1 - A rotor cover for an electric motor - Google Patents
A rotor cover for an electric motor Download PDFInfo
- Publication number
- WO1997045917A1 WO1997045917A1 PCT/BR1997/000021 BR9700021W WO9745917A1 WO 1997045917 A1 WO1997045917 A1 WO 1997045917A1 BR 9700021 W BR9700021 W BR 9700021W WO 9745917 A1 WO9745917 A1 WO 9745917A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- cover
- rotor
- core
- rotor core
- rotor cover
- Prior art date
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
- H02K1/22—Rotating parts of the magnetic circuit
- H02K1/27—Rotor cores with permanent magnets
- H02K1/2706—Inner rotors
- H02K1/272—Inner rotors the magnetisation axis of the magnets being perpendicular to the rotor axis
- H02K1/274—Inner rotors the magnetisation axis of the magnets being perpendicular to the rotor axis the rotor consisting of two or more circumferentially positioned magnets
- H02K1/2753—Inner rotors the magnetisation axis of the magnets being perpendicular to the rotor axis the rotor consisting of two or more circumferentially positioned magnets the rotor consisting of magnets or groups of magnets arranged with alternating polarity
- H02K1/278—Surface mounted magnets; Inset magnets
-
- 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
- H02K1/272—Inner rotors the magnetisation axis of the magnets being perpendicular to the rotor axis
- H02K1/2726—Inner rotors the magnetisation axis of the magnets being perpendicular to the rotor axis the rotor consisting of a single magnet or two or more axially juxtaposed single magnets
Definitions
- the present invention refers to a rotor cover for an electric motor of the type used in hermetic compressors for refrigerating systems .
- the electric motor rotor with permanent magnets comprises magnets which are concentrically mounted to the rotor core and around the motor shaft, and a rotor cover disposed externally to said magnets, so as to maintain them close to said core, avoiding relative radial and circumferential displacements between said parts during the operation of the motor, when the magnets are submitted to centrifugal forces tending to move them away from the rotor core, and to moment (shearing) forces that cause the circumferential displacement of said magnets around the rotor core.
- the rotor cover also avoids the disaggregation and release of magnet fragments resulting from the forces existing thereon, as discussed above.
- the rotor cover is in the form of a metallic tube surrounding the magnet-core assembly. Though allowing the magnets to be retained on said core, said solution has the inconvenience of permitting the appearance of induced currents, which cause electric losses and consequently efficiency losses to the motor.
- a rotor cover for an electric motor said rotor comprising a rotor core having a lateral surrounding surface and opposite end surfaces; and magnet elements disposed around the rotor core and retained thereon in position by said cover, said cover being molded in a single piece, so as to surround at least laterally the core and the faces of the magnet elements which are distinct from those faces seated on the core, said cover being circumferentially locked in relation to the rotor core by the interference between at least part of the inner surface of the cover and the outer surface of the rotor core.
- Figures 1 and la show, schematically and in a cross- sectional view, a rotor cover surrounding different magnet embodiments around a rotor core, according to a rotor cover solution of the present invention
- Figures 2 and 2a show, schematically and in a longitudinal sectional view, a rotor cover surrounding different magnet embodiments around a rotor core, according to the rotor cover solution of figure 1;
- Figures 3 an 3a show, schematically, a rotor cover, which includes magnet elements and which is placed around a rotor core, in a cross-sectional view and in a longitudinal section view, respectively, according to another solution of the present invention
- Figures 4, 4a, 4b and 4c show, schematically, and in a longitudinal cross-sectional view, magnet shapes to be disposed around a rotor core in the rotor cover solutions of the present invention
- Figure 5 shows, schematically and in a cross-sectional view, a rotor cover surrounding magnets around the rotor core and provided with locking projections, according to the present invention.
- the present invention refers to a rotor cover 10, for an electric motor rotor of the type having a rotor core 20 which is to be mounted surrounding at least part of a motor shaft and around which are seated magnet elements 30, usually in the form of magnetic pieces which are circumferentially spaced from each other and retained against an external lateral surface 21 of the rotor core 20, by actuation of said rotor cover 10.
- the covers of the present invention are obtained by molding (injection or casting), including the magnets (figures 1-2 and 4-5), incorporating the magnets (figures 3 and 3a) or may also be defined by said magnets when the latter are cast around the core.
- the cover is obtained, by directly casting magnetic material around the core or into a mold, thus obtaining a magnetic ring which will be later affixed around the rotor core, by gluing, interference or another appropriate technique.
- Obtaining the rotor cover by injection may be achieved directly around the rotor core or previously in a mold, said cover being later affixed to the rotor by an adequate technique.
- the rotor cover 10 incorporates magnet elements 30 in the form of a particulate magnet material, preferably magnet powder, included in bonding material mass which defines the cover and which will be injected, for example, around a mold inside which the rotor core is found.
- the magnet elements in which the magnet elements are incorporated in the cover, the latter may be obtained from rare earths, said magnet elements being bonded together by a bonding material for molding the cover.
- a rotor cover 10 in order to surround at least laterally the core and the faces of the magnet elements 30 which are distinct from those faces seated on the core 20, said rotor cover 10 having a cylindrical external lateral surface 11 and an internal lateral surface 12, with a shape matching with the shape of the core and/or magnet portion to be surrounded by said cover.
- the rotor cover 10 of the present invention is preferably molded in a single piece and is provided with a pair of end flanges 13, each being seated against a respective end face of a pair of end faces of each magnet element 30 and, preferably, a respective end face of the rotor core 20 extending up to the rotor shaft region, in order to provide the axial locking of the cover 10 in relation to the rotor core 20.
- the cover-magnet-rotor core assembly may, for example, comprise fixation elements 40, such as illustrated in figure 2a, for example.
- the rotor cover 10 may be provided with end flanges with any extension, ranging from a null extension value, when the cover has only a lateral walls, up to the maximum extension value, as illustrated.
- the circumferential locking between the rotor cover 10 and the rotor core 20, in order to avoid the circumferential relative movement between said parts during the motor operation, is obtained by the interference between at least one of the surfaces defined by the inner surface of the rotor cover 10 and an adjacent external surface of the rotor core 20, said surfaces being at least one of the surfaces defined by the lateral surface and by the opposite end surface of each of the parts defined by the cover and rotor core.
- the interference is achieved by fitting the superficial projections of at least one of the cover 10 and rotor core 20 parts in respective recesses provided in the other of said parts.
- said superficial projections comprise lateral surface portions surrounding the rotor core, when the latter has a polygonal contour with a finite number of sides, said lateral surface portions being external to a circumference inscribed in said polygonal contour.
- the locking will occur, for example, by superficial projections in the form of radial and/or axial ribs provided in at least one of the surfaces defined by the inner surface of the rotor cover 10 or by the external surface of the rotor core 20, such as illustrated in figures 3 and 3a.
- the rotor cover 10 incorporates radial ribs 14 defined during the manufacturing process of said cover around the rotor core 20 and magnets 30, as well as from the inner lateral surface 12 of said rotor cover 10, each rib defining a spacing element, against which are seated opposite confronting longitudinal lateral edges of two circumferentially adjacent magnets.
- the radial ribs 14 occupy at least part and preferably the whole longitudinal extension of the inner lateral surface 12 of the rotor cover 10.
- the radial ribs 14 are provided from any or both the inner surface of the rotor cover 10 and the outer surface of the rotor core 20, preferably occupying the whole longitudinal extension of the rotor core 20, when said rotor core 20 incorporates magnet spacing elements in its construction.
- the superficial projections further define axial ribs provided from at least one of the parts defined by the end face of the rotor core 20 and by the end flanges 13 of the rotor cover 10.
- the superficial projections comprise radial ribs 23 which are provided along at least part of the longitudinal extension of the outer surface of the rotor core 20 and which act in respective recesses 15 defined on the inner lateral surface 12 of the rotor cover 10, during the manufacturing process thereof. It should be undestood that the desired locking may be achieved with superficial projections comprising at least one radial rib 23 provided from one of the blades that form the rotor core and thus occupying only a short extension of the outer lateral surface of the latter.
- the radial ribs 14 act in recesses 25 provided in the body of the rotor core 20, preferably in the form of female locking elements, against which act male locking elements defined by the radial ribs 14 during the manufacture of the rotor cover 10.
- the determination of the shape and size of the radial ribs is a function of the rotor dimensions, number of motor poles, flow lines in the rotot, etc., as well as of the manufacturing process (difficulty, costs, etc.). Besides the illustrated shape (figure 5), other constructions which also have good results are those with a polygonal profile having chamfered or rounded corners or which may also have a tapered base.
- the rotor cover 10 may further incorporate at least an inner circumferential flange 16, which is radially projected from the inner surface of said rotor cover 10 and which separates, axially, magnet portions 30 disposed along the longitudinal extension of the rotor core 20.
- the inner circumferential flanges 16 are dimensioned so as to minimize the removal of magnet material surrounding the rotor, thereby minimizing the electrical losses of the motor.
- the existing ribs and flanges provide higher structural resistance to the rotor cover 10, since they increase its average thickness and define for said rotor cover 10 a structural cage type shape.
- the magnets 30 should have a prismatical shape, with vertex portions being cut in order to minimize sharp corners, for example with chamfered or rounded vertex portions, such as illustrated in figures 4 and 4b, being preferred the shape in which the internal and external radii of the magnets are off-centered.
- the offsetting of these radii is dimensioned in order to minimize the forces over the cover during the motor operation.
- the shaping of the magnets result in low electrical losses to the motor, it increases the thickness of the rotor cover 10, which improves the structural function thereof.
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Permanent Field Magnets Of Synchronous Machinery (AREA)
Abstract
Description
Claims
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP97929057A EP0913022A1 (en) | 1996-05-29 | 1997-05-23 | A rotor cover for an electric motor |
JP54129797A JP2001516550A (en) | 1996-05-29 | 1997-05-23 | Rotor cover for electric motor |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
BR9601756A BR9601756A (en) | 1996-05-29 | 1996-05-29 | Electric motor rotor cover |
BRPI9601756-2 | 1996-05-29 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO1997045917A1 true WO1997045917A1 (en) | 1997-12-04 |
Family
ID=4064105
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/BR1997/000021 WO1997045917A1 (en) | 1996-05-29 | 1997-05-23 | A rotor cover for an electric motor |
Country Status (5)
Country | Link |
---|---|
EP (1) | EP0913022A1 (en) |
JP (1) | JP2001516550A (en) |
CN (1) | CN1220038A (en) |
BR (1) | BR9601756A (en) |
WO (1) | WO1997045917A1 (en) |
Cited By (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1998037611A2 (en) * | 1997-02-21 | 1998-08-27 | Emerson Electric Co. | Rotor assembly for a rotating machine |
EP0982835A1 (en) * | 1998-08-25 | 2000-03-01 | Mannesmann VDO Aktiengesellschaft | Permanent magnet motor and its use |
GB2353902A (en) * | 1999-08-28 | 2001-03-07 | Aisin Seiki | Canned magnet structure for motor |
EP1193826A2 (en) * | 2000-08-23 | 2002-04-03 | Siemens Aktiengesellschaft | Permanent magnet rotor for a permanent magnet electric drive, particularly an AC main drive |
EP1326319A2 (en) * | 2001-12-25 | 2003-07-09 | Hitachi, Ltd. | Rotor, method of manufacturing the same and rotary machine |
EP1753113A2 (en) | 2005-08-11 | 2007-02-14 | Josef Ott | Stator molding |
EP1720235A3 (en) * | 2001-12-21 | 2007-05-02 | Johnson Electric S.A. | Brushless D.C. motor |
DE102010014597A1 (en) * | 2010-04-09 | 2011-10-13 | Continental Automotive Gmbh | rotor |
DE102010041585A1 (en) * | 2010-09-29 | 2012-03-29 | Siemens Aktiengesellschaft | Rotor for use as inner rotor of e.g. linear electric machine for permanent synchronous generator of wind power station, has permanent magnets mounted on periphery of rotor body where each pocket is intractable and connected with rotor body |
DE102013007235A1 (en) * | 2013-04-26 | 2014-10-30 | SIEVA d.o.o. - poslovna enota Idrija | Brushless inner rotor DC motor |
US9130426B2 (en) * | 2011-10-31 | 2015-09-08 | Regal Beloit America, Inc. | Permanent magnet rotors and methods of assembling the same |
DE102017103936A1 (en) | 2017-02-24 | 2018-08-30 | Minebea Mitsumi Inc. | Rotor with a bearing |
Families Citing this family (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2006025509A (en) * | 2004-07-07 | 2006-01-26 | Nsk Ltd | Motor for electric power steering system and electric power steering system |
CN104362779B (en) * | 2014-11-07 | 2017-10-10 | 上海法雷奥汽车电器系统有限公司 | A kind of efficient utilization dust core material is to reduce the claw-pole motor rotor structure of iron loss |
DE102015102207A1 (en) * | 2015-02-16 | 2016-08-18 | Oase Gmbh | Pump with electric motor |
DE102015206296A1 (en) * | 2015-04-09 | 2016-10-13 | Volkswagen Aktiengesellschaft | electric machine |
KR102452163B1 (en) * | 2017-08-03 | 2022-10-11 | 엘지이노텍 주식회사 | Motor |
CN110538622B (en) * | 2019-09-18 | 2021-08-27 | 江门市新会天御硅制品有限公司 | Chemical reaction kettle |
KR102498790B1 (en) | 2020-11-23 | 2023-02-13 | 포항공과대학교 산학협력단 | 2-segment quasi-Halbach rotor of motor |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS60102854A (en) * | 1983-11-07 | 1985-06-07 | Sanyo Electric Co Ltd | Sealed motor compressor |
JPS61288758A (en) * | 1985-06-14 | 1986-12-18 | Sanyo Electric Co Ltd | Permanent magnet type rotor |
GB2275134A (en) * | 1993-02-09 | 1994-08-17 | Johnson Electric Sa | Encapsulated magnets in a permanent magnet rotor |
-
1996
- 1996-05-29 BR BR9601756A patent/BR9601756A/en not_active Application Discontinuation
-
1997
- 1997-05-23 EP EP97929057A patent/EP0913022A1/en not_active Withdrawn
- 1997-05-23 JP JP54129797A patent/JP2001516550A/en active Pending
- 1997-05-23 WO PCT/BR1997/000021 patent/WO1997045917A1/en not_active Application Discontinuation
- 1997-05-23 CN CN97195025.3A patent/CN1220038A/en active Pending
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS60102854A (en) * | 1983-11-07 | 1985-06-07 | Sanyo Electric Co Ltd | Sealed motor compressor |
JPS61288758A (en) * | 1985-06-14 | 1986-12-18 | Sanyo Electric Co Ltd | Permanent magnet type rotor |
GB2275134A (en) * | 1993-02-09 | 1994-08-17 | Johnson Electric Sa | Encapsulated magnets in a permanent magnet rotor |
Cited By (20)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1998037611A3 (en) * | 1997-02-21 | 1998-11-19 | Emerson Electric Co | Rotor assembly for a rotating machine |
US6078121A (en) * | 1997-02-21 | 2000-06-20 | Emerson Electric Co. | Rotor assembly for a rotating machine |
US6324745B1 (en) | 1997-02-21 | 2001-12-04 | Emerson Electric Co. | Method of assembling a rotor assembly for a rotating machine |
WO1998037611A2 (en) * | 1997-02-21 | 1998-08-27 | Emerson Electric Co. | Rotor assembly for a rotating machine |
EP0982835A1 (en) * | 1998-08-25 | 2000-03-01 | Mannesmann VDO Aktiengesellschaft | Permanent magnet motor and its use |
GB2353902A (en) * | 1999-08-28 | 2001-03-07 | Aisin Seiki | Canned magnet structure for motor |
EP1193826A2 (en) * | 2000-08-23 | 2002-04-03 | Siemens Aktiengesellschaft | Permanent magnet rotor for a permanent magnet electric drive, particularly an AC main drive |
EP1193826A3 (en) * | 2000-08-23 | 2004-02-04 | Siemens Aktiengesellschaft | Permanent magnet rotor for a permanent magnet electric drive, particularly an AC main drive |
US7394174B2 (en) | 2001-12-21 | 2008-07-01 | Johnson Electric S.A. | Brushless D.C. motor |
EP1720235A3 (en) * | 2001-12-21 | 2007-05-02 | Johnson Electric S.A. | Brushless D.C. motor |
EP1326319A2 (en) * | 2001-12-25 | 2003-07-09 | Hitachi, Ltd. | Rotor, method of manufacturing the same and rotary machine |
EP1326319A3 (en) * | 2001-12-25 | 2004-01-28 | Hitachi, Ltd. | Rotor, method of manufacturing the same and rotary machine |
EP1753113A2 (en) | 2005-08-11 | 2007-02-14 | Josef Ott | Stator molding |
EP1753113A3 (en) * | 2005-08-11 | 2007-11-14 | Josef Ott | Stator molding |
DE102010014597A1 (en) * | 2010-04-09 | 2011-10-13 | Continental Automotive Gmbh | rotor |
US9024495B2 (en) | 2010-04-09 | 2015-05-05 | Continental Automotive Gmbh | Rotor |
DE102010041585A1 (en) * | 2010-09-29 | 2012-03-29 | Siemens Aktiengesellschaft | Rotor for use as inner rotor of e.g. linear electric machine for permanent synchronous generator of wind power station, has permanent magnets mounted on periphery of rotor body where each pocket is intractable and connected with rotor body |
US9130426B2 (en) * | 2011-10-31 | 2015-09-08 | Regal Beloit America, Inc. | Permanent magnet rotors and methods of assembling the same |
DE102013007235A1 (en) * | 2013-04-26 | 2014-10-30 | SIEVA d.o.o. - poslovna enota Idrija | Brushless inner rotor DC motor |
DE102017103936A1 (en) | 2017-02-24 | 2018-08-30 | Minebea Mitsumi Inc. | Rotor with a bearing |
Also Published As
Publication number | Publication date |
---|---|
JP2001516550A (en) | 2001-09-25 |
BR9601756A (en) | 1998-09-29 |
EP0913022A1 (en) | 1999-05-06 |
CN1220038A (en) | 1999-06-16 |
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