WO1997018613A1 - A rotor cover for an electric motor - Google Patents
A rotor cover for an electric motor Download PDFInfo
- Publication number
- WO1997018613A1 WO1997018613A1 PCT/BR1996/000047 BR9600047W WO9718613A1 WO 1997018613 A1 WO1997018613 A1 WO 1997018613A1 BR 9600047 W BR9600047 W BR 9600047W WO 9718613 A1 WO9718613 A1 WO 9718613A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- cover
- circumferential
- rotor cover
- rotor
- lateral wall
- 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
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, mounted around a motor shaft, magnets disposed concentrically to the rotor core and a rotor cover disposed externally to said magnets, so as to maintain these close to said core, avoiding relative radial and circumferential displacements between said parts during the operation of the rotor.
- 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 shaft and core.
- the rotor cover still 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. These covers usually present an integral cylindric lateral wall .
- the ferro-magnetic material of the rotor cover allows the existing magnetic field variation to create induced current rings, of long trajectory, occupying a large portion of the integral lateral surface of the cover and resulting in high electric loss and consequently in loss of motor efficiency.
- One solution to reduce the effect of these induced currents is the use of thin covers obtained from thin metallic sheets, such as stainless steel
- the thickness reduction required n order that said covers do not present a significant electric loss makes difficult the handling thereof during the manufacturing process, besides impairing the cover in its structural function .
- a rotor cover for an electric motor which is tubular, metallic and concentrically mounted around the rotor shaft, through a determined axial extension thereof, comprising a cylindric latera L wall provided through its axial extension with a plurality of circumferential regions, spaced from each other and with a lateral wall thickness varying from 5 to about 100% of the nominal thickness of said cylindric lateral wall of the cover, any longitudinal alignment defined on the cover lateral wall, through its axial extension, being divided by a plurality of circumferential regions.
- Figure 1 shows, schematically, a perspective view of a rotor cover, mounted around a rotor shaft, according with a rotor cover construction of the present invention
- Figure 2 shows, schematically, a plan view of a specific constructive form for the rotor cover of the present invention
- Figure 3 shows, schematically and in a longitudinal cross-sectional view, a rotor cover construction, according to the present invention
- Figure 4 shows, schematically, and in a longitudinal cross-sectional view, another rotor cover construction, of the present invention
- Figures 5, 5a and 5b show, schematically and in plan view, other constructive solutions for the rotor cover, obtained according to the present invention.
- Best Wav for Carrying Out the Invention According to the present invention, around a determined axial extension 1 of the rotor cover, there is mounted, concentrically to the latter, a tubular metallic rotor cover 10 surrounding rotor magnets disposed around its shaft, said rotor cover 10 having a cylindric lateral wall 11 with a determined thickness T which varies through the axial extension of said rotor cover 10, as discussed ahead.
- said wall is provided with a plurality of circumferential regions 12, spacedly disposed and preferably parallel to each other and dividing any longitudinal alignment defined on the lateral wall of the cover 10, according to at least one plane secant to the axis of the rotor cover 10, orthogonal to said axis, such as illustrated in Figure 1, or inclined in relation to said axis, such as illustrated in Figure 5.
- said regions present an annular shape.
- each said por ion is contained in a respective plane secant to said axis, said two planes intercepting each other according to an intersection line diametrical to the rotor cover.
- the circumferential regions 12 have a lateral wall thickness varying from 5 to about 100% of the nominal thickness T of the lateral wall 11 of cover 10.
- the solutions that present parallelism between the annular circumferential regions are preferred, in function of the manufacturing advantages and better efficiency, which results in low losses, other solutions for said regions are also possible, such as those having a construction with circumferential regions in undulatory circumferential development, with its wave portions not orthogonal to the rotor shaft being parallel to each other or in phase opposition.
- the rotor cover 10 can be provided with continuous circumferential regions 12 or having at least part of these regions produced in segments, said segmented circumferential regions presenting at least one interruption.
- the circumferential regions 12 are defined in the form of circumferential grooves, each presenting a circumferential extension at most equal to the circumferential extension of the lateral wall 11 of the rotor cover 10.
- said grooves may be continuous, occupying the whole circumferential extension of the rotor cover 10, or present at least one interruption, angularly offset from the interruption of at least one of the adjacent circumferential grooves, in order to avoid the formation of long trajectory induced currents on the lateral wall of the rotor cover 10
- circumferential regions 12 are defined in the form of through cuts, each having a circumferential extension inferior to the circumferential extension of the lateral wall 11 of the rotor covei 10
- each circumferential cut 12 has at least one, preferably two interruptions angularly offset from the interruption or interruptions of the axially adjacent cuts, avoiding the axial alignment of the interruptions on the lateral wall 11 of the rotor cover 10, which would propitiate the formation of long trajectory induced currents on said wall . While the construction with angular offset between interruptions is preferred, constructions not considering this offset can be used, although they do not present such a satisfactory result in reducing the electric loss .
- the interruptions by annular cuts should fulfill the 7/18613 PC17BR96/00047
- the circumferential regions 12 in the form of grooves or cuts when provided with interruptions should divide, at least at each two of said adjacent regions, any longitudinal alignment defined on the lateral wall of the rotor cover 10, that is, it is allowed, at most, the axial aiiqnment of the interruptions of two regions.
- the axial distance between each two adjacent circumferential regions 12 is calculated so as to be minimum, since the reduction ot tht spacing between said cuts results, proportional1 , , in a reduction of the electric losses result nq from the induced currents.
- the spacing is calculated in a way not to impair the structural resistance of the cover.
- the thickness of the circumferential regions is calculated so that the air gap in the region of the respective space of the circumter ent lal cut or groove is sufficient to avoid the presence of the induced currents, without impairing the structural integrity of the cover.
- the thickness of each circumferential region is defined considering also the quantity of cuts or grooves to be produced by unit of axial length of the cylindric lateral wall of the cover.
- the lateral wall of the cover has between 1 and 500 circumferential cuts for each ten centimeters of axial length.
Abstract
A rotor cover for an electric motor, which is tubular, metallic and concentrically mounted around the rotor shaft (1), through a determined axial extension thereof, comprising a cylindric lateral wall (11) provided through its axial extension with a plurality of circumferential regions (12), spaced from each other and with a lateral wall thickness varying from 5 to about 100 % of the nominal thickness of the cylindric lateral wall (11) of the cover (10), any longitudinal alignment defined in said cylindric lateral wall (11), through its axial extension, being divided by a plurality of circumferential regions (12).
Description
A ROTOR COVER FOR AN ELECTRIC MOTOR
Field of the Invention
The present invention refers to a rotor cover for an electric motor of the type used in hermetic compressors for refrigerating systems . Background of the Invention
The electric motor rotor with permanent magnets comprises, mounted around a motor shaft, magnets disposed concentrically to the rotor core and a rotor cover disposed externally to said magnets, so as to maintain these close to said core, avoiding relative radial and circumferential displacements between said parts during the operation of the rotor. During operation, 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 shaft and core. Besides the function of maintaining the magnets close to the core, the rotor cover still avoids the disaggregation and release of magnet fragments resulting from the forces existing thereon, as discussed above. In a known solution, the rotor cover is in the form of a metallic tube surrounding the magnet-core assembly. These covers usually present an integral cylindric lateral wall . During the operation of the rotor, the ferro-magnetic material of the rotor cover allows the existing magnetic field variation to create induced current rings, of long trajectory, occupying a large portion of the integral lateral surface of the cover and resulting in high electric loss and consequently in loss of motor efficiency.
One solution to reduce the effect of these induced currents is the use of thin covers obtained from thin metallic sheets, such as stainless steel However, the thickness reduction required n order that said covers do not present a significant electric loss, makes difficult the handling thereof during the manufacturing process, besides impairing the cover in its structural function . Disclosure of the Invention Thus, it is an object of the present invention to provide a rotor cover for an electnc motor, which minimizes the electric losses ot the motor by minimizing the presence of long trajectory electric currents through the lateral suiface of the cover, without impairing its functions in relation to the permanent magnets of the rotor and which is industrially viable.
These and other objectives a ^e attained by a rotor cover for an electric motor, which is tubular, metallic and concentrically mounted around the rotor shaft, through a determined axial extension thereof, comprising a cylindric latera L wall provided through its axial extension with a plurality of circumferential regions, spaced from each other and with a lateral wall thickness varying from 5 to about 100% of the nominal thickness of said cylindric lateral wall of the cover, any longitudinal alignment defined on the cover lateral wall, through its axial extension, being divided by a plurality of circumferential regions. Brief Description of the Drawings
The invention will be described below with reference to the attached drawings, in which:
Figure 1 shows, schematically, a perspective view of a rotor cover, mounted around a rotor shaft, according with a rotor cover construction of the present invention;
Figure 2 shows, schematically, a plan view of a specific constructive form for the rotor cover of the present invention;
Figure 3 shows, schematically and in a longitudinal cross-sectional view, a rotor cover construction, according to the present invention;
Figure 4 shows, schematically, and in a longitudinal cross-sectional view, another rotor cover construction, of the present invention; and Figures 5, 5a and 5b show, schematically and in plan view, other constructive solutions for the rotor cover, obtained according to the present invention. Best Wav for Carrying Out the Invention According to the present invention, around a determined axial extension 1 of the rotor cover, there is mounted, concentrically to the latter, a tubular metallic rotor cover 10 surrounding rotor magnets disposed around its shaft, said rotor cover 10 having a cylindric lateral wall 11 with a determined thickness T which varies through the axial extension of said rotor cover 10, as discussed ahead.
To avoid the formation of long trajectory induced currents on the lateral wall 11 of the rotor cover 10, said wall is provided with a plurality of circumferential regions 12, spacedly disposed and preferably parallel to each other and dividing any longitudinal alignment defined on the lateral wall of the cover 10, according to at least one plane secant to the axis of the rotor cover 10, orthogonal to said axis, such as illustrated in Figure 1, or inclined in relation to said axis, such as illustrated in Figure 5. In these embodiments, where at least part of the circumferential regions is defined in a single plane cutting the axis of the rotor cover 10, said regions present an annular shape.
Although the constructions mentioned above present a better performance and efficiency and provide better manufacturing conditions, other constructions within the inventive concept presented are also possible, such as those in which at least part of said circumferential regions is defined by two semi-annular portions, such as illustrated in Figures 5a and 5b. In these constructions, each said por ion is contained in a respective plane secant to said axis, said two planes intercepting each other according to an intersection line diametrical to the rotor cover.
In the preferred and illustrated embodiments, the circumferential regions 12 have a lateral wall thickness varying from 5 to about 100% of the nominal thickness T of the lateral wall 11 of cover 10.
Although the solutions that present parallelism between the annular circumferential regions are preferred, in function of the manufacturing advantages and better efficiency, which results in low losses, other solutions for said regions are also possible, such as those having a construction with circumferential regions in undulatory circumferential development, with its wave portions not orthogonal to the rotor shaft being parallel to each other or in phase opposition. To obtain the desired result with the present invention, the rotor cover 10 can be provided with continuous circumferential regions 12 or having at least part of these regions produced in segments, said segmented circumferential regions presenting at least one interruption.
In a preferred and illustrated embodiment, the circumferential regions 12 are defined in the form of circumferential grooves, each presenting a circumferential extension at most equal to the circumferential extension of the lateral wall 11 of the rotor cover 10. In this construction, said grooves may
be continuous, occupying the whole circumferential extension of the rotor cover 10, or present at least one interruption, angularly offset from the interruption of at least one of the adjacent circumferential grooves, in order to avoid the formation of long trajectory induced currents on the lateral wall of the rotor cover 10
In another preferred and illustrated embodiment, the circumferential regions 12 are defined in the form of through cuts, each having a circumferential extension inferior to the circumferential extension of the lateral wall 11 of the rotor covei 10
The provision of cuts with a circumferential extension larger than that of the lateral wall of the rotor cover 10 would result in helical cuts with undesirable consequences to its productive process The provision of cuts with the same extension as the respective portion of the lateral wall of the rotor cover would divide said wall n rings which, though substantially reducing the electric losses, makes difficult the mounting of said rotor covers.
To a 7oιd the division of the rotor cover 10 in rings, each circumferential cut 12 has at least one, preferably two interruptions angularly offset from the interruption or interruptions of the axially adjacent cuts, avoiding the axial alignment of the interruptions on the lateral wall 11 of the rotor cover 10, which would propitiate the formation of long trajectory induced currents on said wall . While the construction with angular offset between interruptions is preferred, constructions not considering this offset can be used, although they do not present such a satisfactory result in reducing the electric loss . The interruptions by annular cuts should fulfill the
7/18613 PC17BR96/00047
conditions of lower electric losses and higher structural rigidity.
To avoid the ocurrence of the long trajectory induced currents, the circumferential regions 12 in the form of grooves or cuts when provided with interruptions, should divide, at least at each two of said adjacent regions, any longitudinal alignment defined on the lateral wall of the rotor cover 10, that is, it is allowed, at most, the axial aiiqnment of the interruptions of two regions.
The axial distance between each two adjacent circumferential regions 12 is calculated so as to be minimum, since the reduction ot tht spacing between said cuts results, proportional1 , , in a reduction of the electric losses result nq from the induced currents. The spacing is calculated in a way not to impair the structural resistance of the cover. Moreover, the thickness of the circumferential regions is calculated so that the air gap in the region of the respective space of the circumter ent lal cut or groove is sufficient to avoid the presence of the induced currents, without impairing the structural integrity of the cover. The thickness of each circumferential region is defined considering also the quantity of cuts or grooves to be produced by unit of axial length of the cylindric lateral wall of the cover.
In a preferred constructive option, the lateral wall of the cover has between 1 and 500 circumferential cuts for each ten centimeters of axial length.
Claims
1. A rotor cover for an electric motor, which is tubular, metallic and concentrically mounted around the rotor shaft (1), through a determined axial extension thereof, characterized in that it comprises a cylindric lateral wall (11) provided through its axial extension with a plurality of circumferential regions (12) , spaced from each other and with a lateral wall thickness varying from 5 to about 100% of the nominal thickness of the cylindric lateral wall (11) of the cover (10) , any longitudinal alignment defined in said cylindric lateral wall (11) , through its axial extension, being divided by a plurality of circumferential regions (12) .
2. A rotor cover, according to claim 1, characterized in that at least part of the circumferential regions (12) is divided through its extension.
3. A rotor cover, according to claim 2, characterized in that each segmented circumferential region (12) has at least one interruption.
4. A rotor cover, according to claim 3, characterized in that the interruptions of each two axially adjacent circumferential regions (12) are angularly offset from each other.
5. A rotor cover, according to claim 1, characterized in that each circumferential region (12) has an annular shape and is defined in a single plane secant to the axis of the cover (10) .
6. A rotor cover, according to claim 5, characterized in that at least part of the circumferential regions (12) is defined in a respective secant plane orthogonal to the axis of the cover (10) .
7. A rotor cover, according to claim 5, characterized in that at least part of the circumferential regions
(12) is defined in a respective secant plane inclined relative to the axis of the cover (10) .
8. A rotor cover, according to claim 1, characterized in that each circumferential region is defined by two semi-annular portions, each portion being contained in a plane secant to the axis oJ the cover (10), both planes defining an intersection line diametral to the cover ( 10 ) .
9. A rotor cover, according to claim 8, characterized n that both secant planes are inclined relative to each other.
10. A rotor cover, according to claim 1, characterized in that the circumferential regions (12) are through cuts with a circumferential extension inferior to the circumferential extension of the cover (10) .
11. A rotor cover, according to claim 1, characterized in that the circumferential regions (12) are grooves with the circumferential extension at most equal to the circumferential extension of the cover (10) .
12. A rotor cover, according to claim 1, characterized in that each circumferential region (12) has an air gap with a thickness calculated so as to be sufficient to minimize the formation of long trajectory induced currents on the cylindric lateral wall (11) , without impairing the structural integrity of the cover, and said thickness being determined based on the quantity of circumferential regions (12) provided by unit of axial length of said lateral wall (11) .
13. A rotor cover, according to claim 1, characterized in that it preferably comprises between 1 and 500 circumferential cuts by each ten centimeters of axial length .
AMENDED CLAIMS
[received by the International Bureau on 18 February 1997 (18.02.97); original claims 1-13 replaced by amended claims 1-10 (2 pages)]
1. A rotor cover for an electric motor, which is tubular, metallic and concentrically mounted around the rotor shaft (1), through a determined axial extension thereof, characterized in that it comprises a cylindric lateral wall (11) provided through its axial extension with a plurality of circumferential regions (12), spaced from each other and with a lateral wall thickness varying from 5 to about 100% of the nominal thickness of the cylindric lateral wall (11) of the cover (10), any longitudinal alignment defined in said cylindric lateral wall (11)/ through its axial extension, being divided by a plurality of circumferential regions (12), at least part of said circumferential regions (12) being divided through its extension, each segmented circumferential region (12) having at least one interruption, the interruptions of each two axially adjacent circumferential regions (12) being angularly offset from each other
2. A rotor cover, according to claim 1, characterized in that each circumferential region (12) has an annular shape and is defined in a single plane secant to the axis of the cover (10) . 3. A rotor cover, according to claim 2, characterized in that at least part of the circumferential regions (12) is defined in a respective secant plane orthogonal to the axis of the cover (10) .
4. A rotor cover, according to claim 2, characterized in that at least part of the circumferential regions
(12) is defined in a respective secant plane inclined relative to the axis of the cover (10) .
5. A rotor cover, according to claim 1, characterized in that each circumferential region is defined by two semi-annular portions, each portion being contained in a plane secant to the axis of the cover (10), both
planes defining an intersection line diametral to the cover ( 10 ) .
6. A rotor cover, according to claim 5, characterized in that both secant planes are inclined relative to each other.
7. A rotor cover, according to claim 1, characterized in that the circumferential regions (12) are through cuts with a circumferential extension inferior to the circumferential extension of the cover (10) 8. A rotor cover, according to claim 1, characterized in that the circumferential regions (12) are grooves with the circumferential extension at most equal to the circumferential extension of the cover (10)
9. A rotor cover, according to claim 1, characterized in that each circumferential region (12) has an air gap with a thickness calculated so as to be sufficient to minimize the formation of long trajectory induced currents on the cylindric lateral wall (11), without impairing the structural integrity of the cover, and said thickness being determined based on the quantity of circumferential regions (12) provided by unit of axial length of said lateral wall (11)
10. A rotor cover, according to claim 1, characterized in that it preferably comprises between 1 and 500 circumferential cuts by each ten centimeters of axial length.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| BR9504941A BR9504941A (en) | 1995-11-13 | 1995-11-13 | Rotor cover for electric motor |
| BRPI9504941-0 | 1995-11-13 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| WO1997018613A1 true WO1997018613A1 (en) | 1997-05-22 |
Family
ID=4062708
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/BR1996/000047 WO1997018613A1 (en) | 1995-11-13 | 1996-10-16 | A rotor cover for an electric motor |
Country Status (2)
| Country | Link |
|---|---|
| BR (1) | BR9504941A (en) |
| WO (1) | WO1997018613A1 (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1065777A1 (en) * | 1999-06-30 | 2001-01-03 | Shin-Etsu Chemical Co., Ltd. | Rare earth-based sintered magnet and permanent magnet synchronous motor therewith |
| EP3068019A3 (en) * | 2015-03-13 | 2016-12-07 | Rolls-Royce plc | Sleeve for an electrical machine |
| CN110277862A (en) * | 2018-03-13 | 2019-09-24 | 本田技研工业株式会社 | Rotating electric machine |
| US11025112B2 (en) | 2017-09-05 | 2021-06-01 | Rolls-Royce Plc | Electrical machine rotor |
| US20230307972A1 (en) * | 2022-03-25 | 2023-09-28 | Beta Air, Llc | Rotor for an electric aircraft motor comprising a plurality of magnets |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS52144715A (en) * | 1976-05-28 | 1977-12-02 | Hitachi Ltd | Cover for reinforing ring-shaped magnet |
| JPS5846856A (en) * | 1981-09-11 | 1983-03-18 | Hitachi Ltd | Permanent magnet rotor |
| JPH06296336A (en) * | 1993-04-06 | 1994-10-21 | Matsushita Electric Ind Co Ltd | Rotor of motor |
| JPH07284238A (en) * | 1994-04-06 | 1995-10-27 | Aichi Emerson Electric Co Ltd | Magnet rotor |
| JPH0865931A (en) * | 1994-08-26 | 1996-03-08 | Hitachi Ltd | Rotor of motor |
-
1995
- 1995-11-13 BR BR9504941A patent/BR9504941A/en not_active IP Right Cessation
-
1996
- 1996-10-16 WO PCT/BR1996/000047 patent/WO1997018613A1/en active Application Filing
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS52144715A (en) * | 1976-05-28 | 1977-12-02 | Hitachi Ltd | Cover for reinforing ring-shaped magnet |
| JPS5846856A (en) * | 1981-09-11 | 1983-03-18 | Hitachi Ltd | Permanent magnet rotor |
| JPH06296336A (en) * | 1993-04-06 | 1994-10-21 | Matsushita Electric Ind Co Ltd | Rotor of motor |
| JPH07284238A (en) * | 1994-04-06 | 1995-10-27 | Aichi Emerson Electric Co Ltd | Magnet rotor |
| JPH0865931A (en) * | 1994-08-26 | 1996-03-08 | Hitachi Ltd | Rotor of motor |
Non-Patent Citations (5)
| Title |
|---|
| PATENT ABSTRACTS OF JAPAN vol. 002, no. 023 (E - 014) 15 February 1978 (1978-02-15) * |
| PATENT ABSTRACTS OF JAPAN vol. 007, no. 132 (E - 180) 9 June 1983 (1983-06-09) * |
| PATENT ABSTRACTS OF JAPAN vol. 94, no. 010 * |
| PATENT ABSTRACTS OF JAPAN vol. 95, no. 010 * |
| PATENT ABSTRACTS OF JAPAN vol. 96, no. 3 * |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1065777A1 (en) * | 1999-06-30 | 2001-01-03 | Shin-Etsu Chemical Co., Ltd. | Rare earth-based sintered magnet and permanent magnet synchronous motor therewith |
| US6606019B1 (en) | 1999-06-30 | 2003-08-12 | Shin-Etsu Chemical Co., Ltd. | Rare earth-based sintered magnet and permanent magnet synchronous motor therewith |
| EP3068019A3 (en) * | 2015-03-13 | 2016-12-07 | Rolls-Royce plc | Sleeve for an electrical machine |
| US10122228B2 (en) | 2015-03-13 | 2018-11-06 | Rolls-Royce Plc | Sleeve for an electrical machine |
| US11025112B2 (en) | 2017-09-05 | 2021-06-01 | Rolls-Royce Plc | Electrical machine rotor |
| CN110277862A (en) * | 2018-03-13 | 2019-09-24 | 本田技研工业株式会社 | Rotating electric machine |
| US20230307972A1 (en) * | 2022-03-25 | 2023-09-28 | Beta Air, Llc | Rotor for an electric aircraft motor comprising a plurality of magnets |
Also Published As
| Publication number | Publication date |
|---|---|
| BR9504941A (en) | 1997-10-21 |
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