HK1007643B - Multiphase electromagnetic transducer with a multipolar permanent magnet - Google Patents
Multiphase electromagnetic transducer with a multipolar permanent magnet Download PDFInfo
- Publication number
- HK1007643B HK1007643B HK98106733.2A HK98106733A HK1007643B HK 1007643 B HK1007643 B HK 1007643B HK 98106733 A HK98106733 A HK 98106733A HK 1007643 B HK1007643 B HK 1007643B
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Description
The present invention relates to a multipolar permanent magnet electromagnetic transducer, in particular a three-phase multipolar permanent magnet transducer with X pairs of poles, X being an even number greater than two, which can be used as a reversible electromechanical transducer.
The electromagnetic transducer of the present invention can be used as a motor in many applications, e.g. for driving discs, coils or cassettes in the computer or audiovisual field.
In the case of an electronic watch, a bi-polar permanent magnet electromagnetic motor is usually used, which operates in step-wise mode, with the rotor rotating 180° per step. If the watch has a seconds hand and the step frequency is 1 Hz, then a factor of 30 is required between the motor rotor and this hand.
Generally speaking, to achieve a nearly continuous step rotation with a bipolar permanent magnet motor, it is necessary to increase the operating frequency of the motor and to provide a mechanism for the decoupling between the rotor of this motor and the device driven by this motor.
Electromagnetic transducers according to the above art are described in US-A-4 922 145 and EP-A-04 580 567.
One purpose of the present invention is to provide an electromagnetic transducer that allows step-by-step operation with a small angular rotor displacement per step.
A second purpose of the invention is to provide such an electromagnetic transducer that can be easily miniaturized at low manufacturing cost, while still having good energy efficiency.
Finally, a third purpose of the invention is to provide such an electromagnetic transducer with a compact structure which ensures good efficiency in the ratio of useful energy to the volume of the transducer.
The present invention therefore concerns an electromagnetic transducer comprising a stator and a rotor mounted in a rotating position relative to that stator, the rotor being capable of rotating about an axis of rotation defined by an axis of positioning of that rotor, and incorporating a multipolar permanent magnet, which defines a rotor plane perpendicular to that axis of rotation and is formed by a set of pairs of rotor poles arranged in a circular manner around that axis of rotation, the number of such pairs of rotor poles being equal to or greater than two, each pair of rotor poles having a magnetic axis,oriented in the direction of the said axis of rotation in the opposite direction to that of the adjacent pairs of rotor poles, and defining an angle α, the value of which is 360° divided by the said number of pairs of rotor poles, in said rotor plane relative to that axis of rotation, the said electromagnetic transducer being characterised by having N magnetic power supplies associated with N magnetic flux guiding branches respectively, N being an integer greater than two, and by comprising the first and second main statoric parts, the first main statoric part defining N main magnetic poles,magnetically isolated from each other by areas of high magnetic resistance, and comprising a first superposition part superimposed on a multipolar permanent magnet relative to a projection in the said rotor plane, each of these main magnetic poles comprising at least one secondary magnetic pole, which is at least partially superimposed on the multipolar permanent magnet relative to a projection in the said rotor plane, the said secondary magnetic poles defining a first static plane parallel to the said rotor plane, each of these secondary magnetic poles defining an angle, in the said static plane relative to that secondary magnetic pole, the value of which at the angle of the said axis is substantially equal to that of α,each secondary pole of each of the said main magnetic poles being angularly offset, relative to each secondary pole of each of the two adjacent main magnetic poles and relative to that axis of rotation, by a deviation angle whose value modulo the value of that angle α is equal to that value of that angle α divided by N, the said second main statoric part defining a return magnetic pole of which a second superposition part is superimposed on this multipolar permanent magnet relative to a projection in said rotoric plane, this second superposition part defining a second statoric plane parallel to this rotoric plane,the first and second stator planes being on either side of the rotor plane, each of the said magnetic flux guiding branches having a first end magnetically connected to a different main magnetic pole and a second end magnetically connected to the return pole.
According to an additional feature of the transducer of the invention, each of the said main magnetic poles of the said first main statoric part comprises at least two secondary magnetic poles, the adjacent secondary magnetic poles belonging to the same main magnetic pole being angularly offset from each other in the said first statoric plane and relative to that axis of rotation by an angle the value of which is substantially equal to twice the value of said angle α.
According to another characteristic of the transducer of the invention, the first and second main statoric parts comprise, respectively, the first and second non-superposed parts of this multipolar permanent magnet relative to a projection in the said rotor plane, these first and second non-superposed parts being respectively located in first and second general planes parallel to each other.
Depending on a particular embodiment of the invention, the first or second main stator part is entirely flat.
In a main embodiment of the invention, the magnetic return pole of the transducer belonging to the second main stator part also includes superimposed secondary poles, relative to a projection in the said rotor plane, at least partially to the said secondary poles of the first main stator part and at least partially to this multipolar permanent magnet, the secondary poles of the second stator part having an angular distribution, in said second stator part relative to this axis of rotation, identical to that of the secondary poles of the first main stator part.
According to particular embodiments of the transducer according to the invention, each secondary magnetic pole of the first main stator and/or the second main stator is formed either by a different tooth of a circular slot, or by a different tooth connected to the other teeth of the same main pole by a rigidization bridge, or by a tip of a ripple forming a ring section, this tip being located on the side of the said multipolar permanent magnet relative to a midplane of the surface of this ripple.
Then, according to specific features of the invention, the first overlay part and/or the second overlay part has at least partial over-thickness in the direction of the multipolar permanent magnet relative to the first and/or second general plane of the stator respectively, or is at least partially bulged in the direction of the multipolar permanent magnet relative to the first and/or second general plane of the stator respectively.
The features of the invention described above are used to achieve the various purposes of the invention.
Other features of the invention will be made even clearer by reading the following description, made with reference to the drawings annexed without limitation, in which:
Figure 1 is a schematic top view of a first embodiment of an electromagnetic transducer according to the invention;Figure 2 is a cut-out view of Figure 1 according to the cut-out line II - II;Figure 3 is a schematic top view of a second main stator part of the first embodiment;Figure 4 is a variant according to the invention of the first embodiment of an electromagnetic transducer according to Figure 1;Figure 5 is a cut-out view of Figure 4 according to the cut-out line V - V;Figure 6 is a schematic top view of a second main stator part of the said variant according to the cut-out line represented in Figure 4;Figure 7 is the second main stator part of a second embodiment of a transducer according to the invention;Figure 8 is a cut-out view according to the cut-out line 8 - a third transducer part according to Figure 8 - a cut-out view of the invention.
A first method of making an electromagnetic transducer according to the invention is described in Figures 1 to 3 below.
This electromagnetic transducer consists of a stator 2 and a rotor 4 mounted in relation to this stator 2 and this rotor 4 consists of a positioning axis 6 which defines a rotation axis 8 and a multipolar permanent magnet 10 which defines a rotor plane 12 perpendicular to the rotation axis 8.
Note that the direction of the magnetic axis 16 of a pair of rotor poles is in the opposite direction to the magnetic axes of the two adjacent pairs of rotor poles. The number of pairs of rotor poles making up the multipolar permanent magnet 10 is an even number greater than two. The pairs of rotor poles are arranged in a circular manner around the rotation axis 8.
In this embodiment, the multipolar permanent magnet 10 is in the form of a ring, comprising 20 pairs of rotor poles 14, with a magnetic disc 18 arranged in the centre of this ring and mounted on the positioning axis 6 of the rotor 4 so that the multipolar permanent magnet 10 is solid with the positioning axis 6.
It should be noted that the positioning axis 6 of rotor 4 can be mounted rotatively relative to stator 2 e.g. by means of a positioning cage (not shown) or by any other means of mounting the rotor of a transducer, especially of an engine, known to the professional.
In the first embodiment, each pair of rotor poles 14 defines in the rotor plane 12 a single angle α with respect to the rotor's axis of rotation 8. Thus, in this first embodiment the angle α is 360°/20 = 18°.
The stator 2 consists of a first main stator 22 and a second main stator 24. The first main stator 22 is located in a first general plane 26, while the second main stator 24 is located in a second general plane 28 of the transducer.
The first statoric part 22 defines three main magnetic poles 30, 31 and 32. These three magnetic poles are magnetically isolated from each other by isthmus 34, 35 and 36, these isthmus having high magnetic refraction. Each of the main poles 30, 31 and 32 includes at least one secondary magnetic pole 38.
In this first embodiment, each of the main poles has three secondary poles.38 Each secondary pole 38 is formed by a tooth 40 extending from the outcrop 42 of the corresponding main magnetic pole in the direction of the rotation axis.8 The set of teeth 40 forms a first circular slot 44 whose merlons are formed by the teeth 40.This first circular slot 44 is arranged in such a way that the teeth 40 are at least partially superimposed on the permanent multipolar magnet 10 relative to a projection in the rotor plane 12.
The set of secondary poles 38 defines a first statoric plane 46, this statoric plane 46 being parallel to the rotoric plane 12. Each of the teeth 40 forming the secondary poles 38 defines an angle in the statoric plane 46 relative to the rotation axis 8 equal to the angle α defined by each pair of rotor poles 14 of the multipolar permanent magnet 10. Thus, each of the teeth defines an angle to the rotation axis 8 equal to 18° in this first embodiment of a transducer according to the invention.
Each of the merlons formed by a tooth 40 is separated from the two adjacent merlons by two braces 50. The angle formed by braces separating two teeth of the same main magnetic pole 30, 31 or 32 defines in the first statoric plane 46 with respect to the axis of rotation 8 an angle equal to the angle α defined by each of the teeth 40 and by each of the pairs of rotor poles 14 of the multipolar permanent magnet 10.
On the other hand, each of the 38 teeth belonging to the same main magnetic pole 30, 31 or 32 is angularly offset relative to a secondary pole belonging to a main magnetic pole adjacent to an angle whose modulo value the value of the angle α is equal to the value of this angle α divided by the number of phases of the transducer, i.e. three phases in the first embodiment.
Each of the three main magnetic poles 30, 31 or 32 comprises a fixing ear 54a, 54b or 54c respectively. Each fixing ear 54a, 54b or 54c allows magnetic contact to be made with a first end 55a, 55b or 55c of a guiding branch of the magnetic flux 56a, 56b or 56c on which a coil 58a, 58b or 58c is mounted, respectively.
Figure 3 shows an overhead view of the second main statoric part 24. This second main statoric part 24 defines a single return magnetic pole 60. This return magnetic pole is defined by a ring part 62 and a second circular slot 64 substantially identical to the first circular slot 44. This second circular slot 64 has teeth 66 also defining secondary magnetic poles 68, the set of teeth 66 defining secondary poles 68 defining a second statoric plane 70. This second statoric plane 70 is located on the other side of the first statoric plane 46 relative to the rotoric plane 12.
The merlons formed by the 66 teeth of the second circular slot 64 and the clampings separating these merlons have an angular distribution in the second stator plane 70 relative to the axis of rotation 8 identical to the said angular distribution of the first circular slot 44 of the first stator part 22.
In order to force the magnetic flux from any of the coils 58a, 58b and 58c to propagate through the rotor pole pairs 14 of the multipolar permanent magnet 10, the circular slot 66 has an over-thickness towards the rotor plane 12 relative to the rest of the second main stator section 24 located in the second general plane 28 of this transducer.
The transducer of the invention shown in Figures 1 to 3 defines three main magnetic circuits, each of which is associated with a different coil 58a, 58b or 58c. In addition, each of these main magnetic circuits is magnetically decoupled from the other two main magnetic circuits. Each main magnetic circuit is formed by a different main magnetic pole 30, 31 or 32, by the guiding branch of the magnetic flux 56a, 56b or 56c connected to this main magnetic pole, and by the return pole defined by the second main statoric part 24.
Given the configuration of the teeth 40 of the first circular slot 44 and the corresponding configuration of the teeth 66 of the second circular slot 64, this transducer can easily operate in step-by-step mode.
The three-phase configuration of the transducer in the first embodiment of the invention thus enables sixty steps per turn to be performed by means of a multipolar magnet 10 comprising only twenty pairs of rotor poles 14 each having a magnetic axis coaxally oriented to the axis of rotation 8.
It should also be noted that the transducer in the first embodiment of the invention has a compact structure resulting in minimal encumbrance.
A variant of the first method of making an electromagnetic transducer according to the invention is described in Figures 4 to 6 below.
The references already discussed in detail in the first mode of implementation described above will not be discussed again for the description of this variant.
It will be noted first that the configuration of the magnetic flux guiding branches 56a, 56b and 56c is in the form of a circle arc, and the coils 58a, 58b and 58c mounted on these magnetic flux guiding branches.
Next, a stabilization ring 80 was provided, magnetic and preferably non-conductive, arranged between the first main stator 22 and the second main stator 24. As shown in Figure 5, this stabilization ring 80 is kept fixed relative to a lateral displacement by the teeth 66 forming the secondary poles 68 of the return pole 60. The teeth 66 belonging to the second main stator 24 have been pushed in the direction of the multipolar permanent magnet 10 relative to the second general plane 28 in which the main of the second main stator 24 is located.
In Figure 4 it is shown that the teeth 40 forming the secondary poles 38 of a single main pole 30, 31 or 32 belonging to the first main statorical part 22 are connected to each other by a rigidizing bridge 84. Thus, the teeth 40 form the window frames 86, these windows 86 corresponding substantially to the brackets of the first embodiment of the invention described in Figures 1 to 3.
It should be noted that the angular distribution of the teeth 40 forming the secondary poles 38 of the first statoric part 22 and of the windows 86 in the first statoric plane 46 is identical with the angular distribution of the merlons and the brackets in the first embodiment described in Figures 1 to 3 respectively.
It will also be noted that preferably the three rigidity bridges 84 are not superimposed on the multipolar permanent magnet 10 relative to a projection in the rotor plane 12.
Similarly to the first stator part 22 of the variant described here, the second stator part 24 of this variant depicted in Figure 6 includes a circular rigidity bridge 88 connecting teeth 66 defining the secondary poles 68 of the return pole 60. Again, teeth 66 form the sums of a set of windows 90 arranged in a circular manner around the axis of rotation 8.
A second method of making an electromagnetic transducer according to the invention is described below by reference to Figures 7 and 8.
This second embodiment of an electromagnetic transducer according to the invention differs from the first embodiment by the shape of the second main statoric part 24 and by the formation of the secondary poles 68 of the return pole 60 formed by this second main statoric part 24 as shown in Figure 7. This second statoric part 24 has in its central region a ringed, wavy region, hereinafter called circular ripple 98, developing around the rotation axis 8 of the rotor 4 (not shown in Figure 7).
The circular ripple 98 is made in such a way that the 104 vertices of this circular ripple 98 located on the side of the multipolar permanent magnet 10 (not shown in Figure 7) relative to a middle plane 102 of the surface of this ripple 98 define the secondary poles 68 of the magnetic pole 60 of return.
Again, the 104 vertices forming the secondary poles 68 have an identical angular distribution to the secondary poles 38 of the first embodiment of the invention.
It should be noted that in a variant (not represented) of this second embodiment of a transducer according to the invention, a rippling is provided for the secondary magnetic poles 38 of the same main pole 30, 31 or 32 belonging to the first main statoric part 22 (reference to Figure 1) similar to that described above. In this variant, three ring-wavy sections are provided, each of these three ring-wavy sections belonging to a same main magnetic pole of the first main statoric part, the peaks of the rippling on the side of the multipolar permanent magnet 10 (reference to Figure 1) defining the secondary poles 38 of this first main statoric part.
A third simplified implementation of the second main statistical part 24 will be described below by reference to Figure 9.
In this simplified mode of construction, the return pole 60 defined by the second main statorical part 24 no longer contains secondary poles.
The surface 114 of the ring part 112 defines a second statoric plane, which is located on the side of the multipolar permanent magnet (not shown in Figure 9) relative to the surface 116 of the complementary part of the second main statoric part 24.
In general, it will be noted that the embodiment chosen for the first main stator part may be independent of the embodiment chosen for the second main stator part.
It should be noted that in a simplified embodiment, the first and second main static parts can be entirely flat, in which case it is possible to provide a configuration in which the superposition region between the two main static parts is minimal outside the region of the multipolar permanent magnet, in order to minimize the losses of magnetic flux.
Finally, it will be noted that the invention described here with a three-phase transducer can be easily applied to a transducer with more phases, including a pentaphase transducer.
Claims (19)
- Electromagnetic transducer comprising a stator (2) and a rotor (4) mounted to rotate relative to the stator, said rotor being adapted to spin around a rotation axis (8), defined by a positioning axle (6) of such rotor, and including a multipolar permanent magnet (10) which defines a rotor plane (12) perpendicular to said rotation axis and is formed by a set of rotor pole pairs (14) arranged in a circular manner about said rotation axis, the number of such rotor pole pairs (14) being even and greater than two, each rotor pole pair having a magnetic axis (16) oriented along the direction of said rotation axis (8) with a sense opposite to that of the adjacent pole pairs and defining an angle α in said rotor plane relative to said rotation axis the value of which is equal to 360° divided by said number of rotor pole pairs, said electromagnetic transducer being characterized in that it includes N magnetic energization means (58a, 58b, 58c) respectively associated with N magnetic flux guidance branches (56a, 56b, 56c), N being an integer greater than two, and in that it comprises first and second principal stator parts (22 and 24), the first principal stator part (22) defining N principal magnetic poles (30, 31, 32) magnetically insulated from one another by zones of high magnetic reluctance (34, 35, 36) and comprising a first superposition portion superposed onto said multipolar permanent magnet relative to a projection thereof in said rotor plane (12), each of such principal magnetic poles comprising at least one secondary magnetic pole (38), which is at least partially superposed onto said said multipolar permanent magnet (10) relative to a projection thereof in said rotor plane, said secondary magnetic poles defining a first stator plane (46) parallel to said rotor plane, each secondary magnetic pole defining in said first stator plane an angle relative to said rotation axis the value of which is equal to that of said angle α, each secondary pole of each of said principal magnetic poles being angularly shifted relative to each secondary pole of each of the two adjacent principal magnetic poles and relative to said rotation axis by a deviation angle the value of which, modulo the value of said angle α is equal to said value of such angle αdivided by N, said second principal stator part (24) defining a magnetic return pole (60) a second superposition portion of which is superposed onto said multipolar permanent magnet relative to a projection thereof in said rotor plane (12), such second superposition portion defining a second stator plane (70) parallel to said rotor plane, said first and second stator planes being located on either side of said rotor plane, each of said magnetic flux guidance branches having a first end (55a, 55b, 55c) magnetically coupled to a different said principal magnetic pole and a second end (79a, 79b, 79c) magnetically coupled to said return pole.
- Transducer according to claim 1, characterized in that each of said principal magnetic poles (30, 31, 32) of said first principal stator part (22) comprises at least two secondary magnetic poles (38), the adjacent secondary magnetic poles belonging to a common principal magnetic pole being angularly shifted relative to one another in the first stator plane (46) and relative to said rotation axis (8) through an angle the value of which is equal to twice the value of said angle α .
- Transducer according to claim 2, characterized in that said first and second principal stator parts (22 and 24) respectively comprise first and second portions which are not superposed onto said permanent magnet relative to a projection thereof in said rotor plane (12), such first and second non-superposed portions being respectively basically located in first and second general planes (26 and 28) parallel to one another, said magnetic flux guidance branches (56a 56b, 56c) being basically located in the region comprised between such first and second general planes, each of said magnetic energization means (58a, 58b, 58c) being formed by a coil on a different said branch.
- Transducer according to claim 2 or 3, characterized in that said first principal stator part (22) is entirely planar and located in said first general plane (26).
- Transducer according to claim 2 or 3, characterized in that said first superposition portion of said first principal stator part (22) exhibits at least partially an over-thickness relative to said first general plane (26) in the direction of said multipolar permanent magnet (10).
- Transducer according to claim 2 or 3, characterized said first superposition portion of said first principal stator part (22) is at least partially dished relative to said first general plane (26) in the direction of said multipolar permanent magnet (10).
- Electromagnetic transducer according to any one of claims 2 to 6, characterized in that said secondary poles (38) of said first principal stator part (22) are formed by the teeth (40) of a first circular crenellation (44).
- Transducer according to any one of claims 2 to 6, characterized in that the secondary poles (38) belonging to a common principal magnetic pole (30, 31, 32) of said first principal stator part (22) are formed by teeth (40) coupled among themselves by a stiffening bridge (84) so as to define at least one window (86).
- Transducer according to claim 2 or 3, characterized in that the first superposition portion of said first principal stator part (22) is undulated, each of said secondary magnetic poles (38) of such first principal stator part being formed by a summit of such undulated superposition portion, such summit being located at the side of said multipolar permanent magnet (10) relative to a median plane of the surface of such undulated first superposition portion, such latter forming N undulated annular sections, each of such undulated annular sections belonging to a different principal magnetic pole (30, 31, 32).
- Transducer according to any one of claims 2 to 9, characterized in that said second superposition portion defines a filled-in annular portion (112) of said second principal stator part (24).
- Transducer according to any one of claims 2 to 9, characterized in that said return magnetic pole (60) of said second principal stator part (24) also includes secondary poles (68) superposed relative to a projection thereof onto said rotor plane (12), at least partially onto said secondary poles (38) of said first principal stator part (22) and at least partially onto said multipolar permanent magnet (10), the secondary poles (68) of the second principal stator part having an angular distribution in said second stator plane (70) relative to said rotation axis (8) identical to that of the secondary poles (38) of the first principal stator part.
- Transducer according to claim 11, characterized in that said first and second superposition portions are entirely superposed onto one another relative to a projection thereof onto said rotor plane (12).
- Transducer according to claim 11 or 12, characterized in that said secondary poles (68) of said return magnetic pole (60) are formed by the teeth (66) of a second circular crenellation (64).
- Transducer according to claim 11 or 12, characterized in that said secondary poles (68) of said return magnetic pole (60) are formed by teeth (66) coupled among themselves by a circular stiffening bridge (88) in a manner to define a set of windows (90) circularly arranged around said rotation axis (8).
- Transducer according to any one of claims 10 to 14, characterized in that said second superposition portion of said second principal stator part (24) exhibits at least partially an over-thickness in the direction of said multipolar permanent magnet (10) relative to said second general plane (28).
- Transducer according to any one of claims 10 to 14, characterized in that said second superposition portion is at least partially dished in the direction of said multipolar permanent magnet (10) relative to said second general plane (28).
- Transducer according to claim 12 or 13, characterized in that said second superposition portion exhibits an undulation (98), each of said secondary poles (68) of said return magnetic pole (60) being formed by a summit (104) of such undulation, such summit being located on the side of said multipolar permanent magnet (10) relative to the median plane (102) of the surface of such undulation (98).
- Electromagnetic transducer according to any one of claims 1 to 17, characterized in that it comprises a stabilization ring (80) arranged between said first and second principal stator parts (22 and 24).
- Transducer according to any one of the preceding claims, characterized in that it is of the three-phase type, N being equal to 3.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR9211511 | 1992-09-24 | ||
| FR9211511A FR2696058B1 (en) | 1992-09-24 | 1992-09-24 | Polyphase electromagnetic transducer with multipolar permanent magnet. |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| HK1007643B true HK1007643B (en) | 1999-04-16 |
| HK1007643A1 HK1007643A1 (en) | 1999-04-16 |
Family
ID=9433940
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| HK98106733A HK1007643A1 (en) | 1992-09-24 | 1998-06-25 | Multiphase electromagnetic transducer with a multipolar permanent magnet |
Country Status (9)
| Country | Link |
|---|---|
| US (1) | US5396139A (en) |
| EP (1) | EP0589342B1 (en) |
| JP (1) | JP3411640B2 (en) |
| KR (1) | KR100303695B1 (en) |
| CN (1) | CN1033883C (en) |
| DE (1) | DE69301216T2 (en) |
| FR (1) | FR2696058B1 (en) |
| HK (1) | HK1007643A1 (en) |
| TW (1) | TW275724B (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AU1299595A (en) * | 1993-12-03 | 1995-06-19 | Maxtor Corporation | Axial spindle motor for hard disk drive assembly |
| TW293965B (en) * | 1993-12-28 | 1996-12-21 | Ebauchesfabrik Eta Ag | |
| DE4429259A1 (en) * | 1994-08-18 | 1996-02-22 | Moto Meter Gmbh | Stepper motor with predominantly axial rotor magnetization |
| US5736798A (en) * | 1995-10-19 | 1998-04-07 | Eastman Kodak Company | Passive magnetic damper |
| FR2745129B1 (en) * | 1996-02-15 | 1998-04-10 | Ebauchesfabrik Eta Ag | ELECTROMECHANICAL TRANSDUCER WITH PERMANENT MULTIPOLAR MAGNETS |
| DE20314652U1 (en) * | 2003-09-22 | 2004-08-26 | Minebea Co., Ltd. | Electric motor with axial magnetic flux for e.g. pumps, fans, toys and centrifuges, has stator yoke made from connected sections with phase windings between poles |
| JPWO2008032410A1 (en) * | 2006-09-11 | 2010-01-21 | 猪一 奥野 | Generator configured to generate electricity with ring-shaped rotation |
Family Cites Families (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2553359A (en) * | 1948-09-30 | 1951-05-15 | Laclede Christy Company | Deairing method |
| US3818690A (en) * | 1973-11-21 | 1974-06-25 | Timex Corp | Stepping motor for watch movement |
| DE2705685A1 (en) * | 1977-02-11 | 1978-08-17 | Quarz Zeit Ag | SINGLE-PHASE STEPPER MOTOR |
| GB2054978B (en) * | 1979-07-06 | 1984-06-13 | Ebauches Sa | Electromagnetic motor rotatable in either direction |
| US4680494A (en) * | 1983-07-28 | 1987-07-14 | Michel Grosjean | Multiphase motor with facially magnetized rotor having N/2 pairs of poles per face |
| WO1985000706A1 (en) * | 1983-07-28 | 1985-02-14 | Michel Grosjean | Multiphase motor with magnetized rotor having n/2 pairs of poles at its periphery |
| CH665069A5 (en) * | 1985-12-11 | 1988-04-15 | Portescap | SINGLE-STAGE DI- OR TETRAPHASE SYNCHRONOUS ELECTRIC MOTOR. |
| US4922145A (en) * | 1988-11-17 | 1990-05-01 | Eastman Kodak Company | Stepper motor |
| EP0458056B1 (en) * | 1990-04-23 | 1995-01-18 | Eta SA Fabriques d'Ebauches | Electromagnetic motor |
| CH681500B5 (en) * | 1991-04-19 | 1993-10-15 | Ebauchesfabrik Eta Ag | electromagnetic motor with two directions of rotation, in particular for a timepiece. |
| FR2679714B1 (en) * | 1991-07-22 | 1995-01-06 | Ebauchesfabrik Eta Ag | POLYPHASE ELECTROMAGNETIC TRANSDUCER WITH PERMANENT MAGNET, ESPECIALLY DRIVE MOTOR. |
| FR2685144B1 (en) * | 1991-12-17 | 1997-09-12 | Ebauchesfabrik Eta Ag | ELECTROMAGNETIC TRANSDUCER WITH MULTIPOLAR PERMANENT MAGNET. |
-
1992
- 1992-09-24 FR FR9211511A patent/FR2696058B1/en not_active Expired - Fee Related
-
1993
- 1993-09-07 TW TW082107374A patent/TW275724B/zh active
- 1993-09-09 US US08/123,845 patent/US5396139A/en not_active Expired - Fee Related
- 1993-09-15 DE DE69301216T patent/DE69301216T2/en not_active Expired - Fee Related
- 1993-09-15 EP EP93114819A patent/EP0589342B1/en not_active Expired - Lifetime
- 1993-09-22 KR KR1019930019229A patent/KR100303695B1/en not_active Expired - Fee Related
- 1993-09-23 CN CN93117893A patent/CN1033883C/en not_active Expired - Fee Related
- 1993-09-24 JP JP25894193A patent/JP3411640B2/en not_active Expired - Fee Related
-
1998
- 1998-06-25 HK HK98106733A patent/HK1007643A1/en not_active IP Right Cessation
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