US20020036437A1 - Structure of roters in stepping motors - Google Patents
Structure of roters in stepping motors Download PDFInfo
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- US20020036437A1 US20020036437A1 US09/960,927 US96092701A US2002036437A1 US 20020036437 A1 US20020036437 A1 US 20020036437A1 US 96092701 A US96092701 A US 96092701A US 2002036437 A1 US2002036437 A1 US 2002036437A1
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- magnetic component
- rotor
- portions
- magnetic
- stepping motor
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K37/00—Motors with rotor rotating step by step and without interrupter or commutator driven by the rotor, e.g. stepping motors
- H02K37/10—Motors with rotor rotating step by step and without interrupter or commutator driven by the rotor, e.g. stepping motors of permanent magnet type
- H02K37/12—Motors with rotor rotating step by step and without interrupter or commutator driven by the rotor, e.g. stepping motors of permanent magnet type with stationary armatures and rotating magnets
- H02K37/14—Motors with rotor rotating step by step and without interrupter or commutator driven by the rotor, e.g. stepping motors of permanent magnet type with stationary armatures and rotating magnets with magnets rotating within the armatures
- H02K37/18—Motors with rotor rotating step by step and without interrupter or commutator driven by the rotor, e.g. stepping motors of permanent magnet type with stationary armatures and rotating magnets with magnets rotating within the armatures of homopolar type
Definitions
- the present invention relates to a structure of a rotor in a stepping motor, widely used for paper-feeders in facsimiles and scanners in copying machines.
- An example of prior art is a stepping motor having a rotor comprising a permanent magnet between two rotating components that are held by the rotor axis at an appropriate spacing, and one of the rotating component is magnetized as N-pole and the other as S-pole (see FIG. 4 in Japanese Patent Laid-open No. Hei 10-80124), or stepping motors having a rotor comprising a cylindrical permanent magnet with multi-polar magnetic parts arranged around the circumference thereof (see FIGS. 1 and 2 in the above-mentioned Japanese Patent), or a configuration as shown in FIGS. 14A and 14B.
- the stepping motor shown in FIG. 14A has a stator yoke 42 in a housing 41 , and enables a rotor 44 to rotate by bearings 43 a and 43 b .
- the stator yoke is wound by a coil 46 connected with lead wire 45 to an electric circuit (not shown).
- the rotor 44 includes a rotor axis 47 , rotor components 48 a and 48 b where a plurality of thin steel plates shaped as an approximate gear are stacked at a predetermined spacing and fixed on the rotor axis 47 , and magnet 49 , as shown in FIGS. 14A and 14B.
- one of the prior art for example, (as disclosed in FIG. 4 of the above-mentioned Japanese Patent), wherein a permanent magnet is provided between two rotor components, is apt to make undesired vibration and/or noises because such a structure has magnetic salient portions (teeth) on the circumferential portion.
- the vibration and noises are also problems found in a prior art shown in FIGS. 14A and 14B.
- the stepping motor having a rotor provided with a cylindrical permanent magnet with multi-polar magnetic parts arranged around the circumferential surface thereof (disclosed in FIGS. 1 and 2 of the above-mentioned Japanese Patent), this prior art is designed to eliminate vibration and noise problems.
- the present invention is to provide a structure of a rotor in stepping motors capable of not only rotating much faster, but also eliminating undesired vibration and noises even under rotation at high speed.
- Another object of the present invention is to provide the structure of rotor capable of performing with two-phase type, and in addition, a simpler and more cost-effective motor manufacturing equipment can be built according
- a structure of a rotor in a stepping motor having a rotor comprising magnetic component whose circumferential part is magnetized in multipole along the circumferential surface thereof, the stepping motor being capable of forcing the rotor to rotate by magnetic force provided between magnetic poles of the rotor and excited salient poles of a stator, characterized in that the magnetic component comprises two magnetic component portions each shaped as an approximate ring, and the two magnetic component portions are either combined with each other or set up separately at appropriate spacing inbetween.
- the two magnetic component portions have a plurality of N-poles and a plurality of S-poles, said N-poles and S-poles each being magnetized alternately at appropriate spacing inbetween, and the N-poles and S-poles are arranged such that contrary poles face each other.
- the convex portions are radially magnetized so that the convex portions on one magnetic component portion have the contrary pole to the convex portions on the other magnetic component portion, and said convex portions are so arranged that they are in aligned viewed in the axial direction.
- the two magnetic component portions are magnetized with poles contrary to each other, and the two magnetic component portions have convex portions opposing to concave portions when viewed in the axial direction.
- FIG. 1 is a sectional view showing a stepping motor according to a first embodiment of the present invention
- FIGS. 2A and 2B show a rotor of the stepping motor in FIG 1
- FIG. 2A is a perspective view showing the rotor whose two magnetic component portions are combined with each other in the axial direction
- FIG. 2B is a perspective view showing the rotor whose two magnetic component portions are arranged at an appropriate vacant spacing in the axial direction;
- FIGS. 3A and 3B show a stator yoke, FIG. 3A is a perspective view thereof, and FIG. 3B is a front view thereof;
- FIGS. 4A, 4B and 4 C show a stator yoke according to a second embodiment of the present invention
- FIG. 4A is a perspective view thereof
- FIG 4 B is a sectional view taken along the line X-X in FIG. 4A
- FIG. 4C is a sectional view taken along the line Y-Y in FIG. 4A;
- FIG. 5 is a sectional view of the stator and the rotor taken along the line X-X in FIG. 4A;
- FIG. 6 is a sectional view of the stator and the rotor taken along the line Y-Y in FIG. 4A;
- FIGS. 7A and 7B show a rotor according to a third embodiment of the present invention
- FIG. 7A is a perspective view showing the rotor whose two magnetic component portions are combined with each other in the axial direction
- FIG. 7B is a perspective view showing the rotor whose two magnetic component portions are arranged at an appropriate vacant spacing in the axial direction;
- FIGS. 8A and 8B show a rotor according to a fourth embodiment of the present invention
- FIG. 8A is a perspective view showing the rotor whose two magnetic component portions are combined with each other in the axial direction
- FIG. 8B is a perspective view showing the rotor whose two magnetic component portions are arranged( at an appropriate vacant spacing in the axial direction;
- FIGS. 9A and 9B show a rotor according to a fifth embodiment of the present invention
- FIG. 9A is a perspective view showing the rotor whose two magnetic component portions are combined with each other in the axial direction
- FIG. 9B is a perspective view showing the rotor whose two magnetic component portions are arranged at an appropriate vacant spacing in the axial direction;
- FIGS. 10A and 10B show a rotor according to a sixth embodiment of the present invention
- FIG. 10A is a perspective view showing the rotor whose two magnetic component portions are combined with each other in the axial direction
- FIG. 10B is a perspective view showing the rotor whose two magnetic component portions are arranged at an appropriate vacant spacing in the axial direction;
- FIG. 11 is a sectional view showing the rotor in FIG. 9 or 10 and a stator used for the rotor;
- FIG. 12 is a sectional view showing the rotor in FIG. 9 or 10 and a stator used for the rotor;
- FIGS. 13A and 13B show a rotor of the stepping motor according to a seventh embodiment of the present invention
- FIG. 13A is a perspective view showing the rotor whose two magnetic component portions are combined with each other in the axial direction
- FIG. 13B is a perspective view showing the rotor whose two magnetic component portions are arranged at an appropriate vacant spacing in the axial direction;
- FIG. 14A is a sectional view showing a conventional stepping motor
- FIG. 14B is a perspective view showing a rotor in the stepping motor in FIG. 14A.
- FIGS. 1 to 3 a first embodiment of the present invention is described as follows.
- a stepping motor referred to as the first embodiment of the present invention has a stator 3 equipped in a housing 20 , and enables a rotor 2 to rotate around a bearing 21 as shown in FIG 1 , and the rotor 2 comprises mainly a rotor axis 4 capable of rotating freely as being held by the bearing 21 , and a magnetic component 5 that held by the rotor 4 by means of supporting portions (not shown) as shown in FIG 2 .
- the magnetic component 5 comprises magnetic component portions 6 and 7 each shaped as an approximate ring. With regard to the magnetic component portions 6 and 7 , it is possible that they are so fabricated that both of them are either combined firmly with each other in the axial direction as shown in FIG. 2A, or arranged separately at an appropriate vacant spacing inbetween in the axial direction as shown in FIG. 2B. For the convenience, hereinafter with regard to the magnetic component portions 6 and 7 , the portion located at the left hand in FIGS. 2A and 2B is called a first magnetic component portion 6 and the other one at the right hand a second magnetic component portion 7 .
- N-poles and S-poles are arranged and magnetized alternately.
- the first and second magnetic component portions 6 and 7 are either combined with each other in the axial direction, or disposed at a predetermined spacing E, and before and after that arrangement the magnetic component portions are magnetized.
- the N-poles and S-poles of the first and second magnetic component portions 6 and 7 are arranged so that contrary poles face each other.
- an N-pole of the first magnetic component portion 6 is juxtaposed next to an S-pole of the second component portion 7 when viewed from the viewing angle along the axis 4 of the rotor.
- the stator 3 comprises an approximate-rectangular stator yoke 8 having a hole (whose reference numeral is omitted) at its central part, through which the rotor 2 is inserted, and a coil 9 is wound around the stator yoke 8 .
- the coil 9 is connected with lead wire 22 to an electric circuit (not shown).
- the stator yoke 8 comprises a laminated sheet made of a plurality of thin steel plates.
- a magnetic salient portion 12 is provided at the top of each leg 11 of the core located inside the stator yoke 8 , and the magnetic salient portion 12 is facing towards the coil 9 .
- a plurality of tooth 13 are formed on the circumferential surface of the magnetic salient portion 12 around the circular surface of the magnet salient portion 12 .
- a gap (whose reference numeral is omitted) is formed between the teeth 13 and the rotor 2 .
- stator 3 can be comprised of first and second stator yoke components 14 and 15 capable of being incorporated in, respectively (see FIG. 4 concerning a second embodiment of the present invention described herein later), and the first and second stator yoke components are so arranged that the two yoke components arc displaced with angle of either 90° or 180° with each other
- the coils 9 are provided correspondingly for the first and second magnetic component portions 6 and 7 , and capable of producing magnetic force (both attractive and repulsive) between the coil 9 and the first magnetic component portion 6 , and also between the coil 9 and the second magnetic component portion 7 .
- the first and second magnetic component portions 6 and 7 are so arranged that contrary poles oppose each other in terms of their physical structure.
- the magnetic component 5 of the rotor 2 described beforehand in the first embodiment takes a ring formation so that the distribution curve of the magnetic flux density in the magnetic field is of sine wave.
- the motor gives less vibration and noises than that have teeth on the circumferential surface of the rotor, and furthermore it has smaller inertia and thus able to perform with much faster response.
- the magnetic component 5 is composed of the combination of the first and second magnetic component portions 6 and 7 (see FIG. 2A), each portion is able to receive magnetic force independently, thus resulting in good controllability of the motor as applied with two-phase type.
- the magnetic component 5 comprises first and second magnetic component portions 6 and 7
- a preferable magnetizing apparatus can be designed on the basis of the first and second magnetic component portions 6 and 7 , thus the magnetizing apparatus should be smaller and hence the entire manufacturing equipment can be made smaller than before.
- FIGS. 4 to 6 a second embodiment of the present invention is described as follows.
- the stator yoke 8 of the stator 3 is composed of two stator yoke components 14 and 15 , which can be combined with each other.
- the portion located at the left hand in FIG. 4A is called a first stator yoke component 14 and the other one at the right hand a second stator yoke component 14 .
- the first and second stator yoke components 14 and 15 comprise a laminated sheet made of plural thin steel plates in the same size.
- first and second stator yoke components 14 and 15 are so arranged that the two components are arranged in aberrant position displaced each other by angle of either 90° or 180°, and with regard to the first and second magnetic component portions 6 and 7 , they are arranged so that contrary poles oppose each other in terms of physical structure, this type of stepping motor proves itself to be more controllable with two-phase type, just as described in the first embodiment of the present invention.
- this type of stepping motor according to the present invention is capable of preventing undesired vibration and noises, rotating with faster speed, being more controllable with two-phase type, making the manufacturing equipment smaller, and thus reducing the manufacturing cost.
- the steel plates can be prepared with only one type of die, because the first and second stator yoke component portions 14 and 15 are made of a plurality of thin steel plates in the same size, thus the manufacturing equipment can be simpler.
- each shape of the first and second magnetic component portions 6 and 7 is of a ring, however, instead of ring shape, an approximate gear shape is also applicable for the first and second magnetic component portions 6 and 7 as shown in FIG. 7 (as a third embodiment) or FIG. 8 (as a fourth embodiment).
- the first and second magnetic component portions 6 and 7 can be either combined with each other in the axial direction as shown in FIG. 7A, or arranged at an appropriate vacant spacing in-between in the axial direction as shown in FIG. 7B.
- Such the construction principle is also applied for the fourth embodiment of the present invention (see FIGS. 8A and 8B) in the same manner, and corresponding constructions are shown in FIGS. 8A and 8B, respectively.
- This concept of the constructions is the same in the fifth (see FIGS. 10A and 10B) and the sixth (see FIGS. 13A and 13B) embodiments of the present inventions and each corresponding construction is shown separately in FIGS. 9, 11 and 13 .
- the first and second magnetic component portions 6 and 7 have convex portions 6 a and 7 a , having a lengthy rectangular physique, formed in the axial direction at appropriate spacing being like an approximate gear on the circumferential surface of each portion as shown in FIGS. 7A and 7B.
- the convex portion 6 a of the first magnetic component portion 6 and the convex portion 7 a of the magnetic component portion 7 are magnetized in the radial direction, so that contrary poles face each other when viewed in the axial direction.
- the convex portion 6 a of the first magnetic component portion 6 is magnetized as N-pole
- the convex portion 7 a of the magnetic component portion 7 as S-pole.
- the first and second magnetic component portions 6 and 7 are combined or disposed at a predetermined spacing E in the axial direction, and the convex portions 6 a and 7 a are arranged so that a convex portion opposes a concave portion.
- the convex portion 6 a (N-pole) of the first magnetic component portion 6 is juxtaposed next to a reentrant (concave) portion (whose reference numeral is omitted) between two convex portions 7 a (S-pole) of the second magnetic component portion 7 , and the first and second magnetic component portions are combined in the axial direction (FIG. 7A), or disposed at a predetermined spacing E (FIG. 7B).
- the third embodiment of the present invention is capable of doing a fine control over the motor performance with two-phase type, and also constructing of a smaller manufacturing equipment is possible by the same reason for the first and second embodiments of the present invention.
- circular reentrant (concave) portions 16 are formed at either side of the combined portion of the first and second magnetic component portions, as shown in FIGS. 8A and 8B.
- the fourth embodiment of the present invention is capable of rotating much faster than the third embodiment because now that it is lighter as the circular reentrant (concave) portion 16 is formed at either side of the combined portion of the first and second magnetic component portions.
- the convex portions 6 a and 7 a on the first and second magnetic component portions 6 and 7 are formed in positions, and either combined or disposed at a predetermined spacing E, however, it is also possible that the convex portions 6 a and 7 a are aligned in series (more specifically, the convex portion 6 a (N-pole) of the magnetic component portion 6 is aligned with convex portion 7 a (S-pole) of the magnetic component portion 7 in series in the axial direction), and both magnetic component portions are either combined each other or disposed at a predetermined spacing E.
- the fifth embodiment of the present invention is capable of doing a fine control over the motor performance with two-phase type, and also constructing a smaller manufacturing equipment is possible
- the sixth embodiment of the present invention is capable of rotating much faster than before because now that it is lighter as the circular reentrant (concave) portion 16 is introduced into either side of the combined portion of the first and second magnetic component portions 6 and 7 .
- the rotors are exemplified wherein the diameter of the first magnetic component portion 6 which includes the convex portion 6 a is the same as that of the second magnetic component 7 which includes the convex portion 7 a , however, instead it is possible that the diameter of the first magnetic component portion 6 is different from that of the second magnetic component portion 7 (a seventh embodiment of the present invention).
- the magnetic component comprises two magnetic component portions magnetized in multipole on their circumferential surfaces, being either combined with each other or disposed at a predetermined spacing, and shaped as an approximate ring.
- the distribution curve of magnetic flux in the magnetic field is of sine wave, which means that this type of stepping motor prevents undesired vibration and noises more than other types that have teeth on the circumferential surfaces of their rotors.
- the type of stepping motor according to the present invention has; a smaller inertia and faster-response ability because the magnetic component in the rotor is ring-like.
- the magnetic component comprises two magnetic component portions being either combined with each other or arranged at an appropriate spacing, and the respective portions are capable of receiving magnetic force independently, thus resulting in better performance with regard to controllability with the two-phase type.
- the magnetizing apparatus can be smaller on the basis of the physical size of the two magnetic component portions, because the magnetic component comprises two magnetic component portions, thus constructing a smaller sized manufacturing equipment is possible.
- the magnetic component comprises two magnetic component portions being either combined with each other or arranged at an appropriate spacing, and the respective portions are capable of receiving magnetic force independently, thereby resulting in better performance with regard to controllability with the two-phase type.
- the magnetizing apparatus can be smaller on the basis of the physical size of the two magnetic component portions, because the magnetic component comprises two magnetic component portions. Thus, it is possible to construct a smaller sized manufacturing equipment.
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Abstract
The objects of the present invention is to provide a stepping motors capable of rotating with not only high speed but also less undesired vibration and noises, and moreover enabling a simpler, smaller manufacturing equipment thereof to be constructed.
A magnetic component 5 of the present invention comprises a magnetic component potions 6 and 7, of which circumferential surface portions each are magnetized in multipole along their circumferential surfaces or magnetized radially in the radial direction, and the magnetic component portions are set up together in the axial direction. As the magnetic component portions 6 and 7 of the magnetic component 5 in the rotor 2 are formed ring-like, the distribution curve of the magnetic flux in the magnetic field is a sine wave, thus this type of stepping motor is capable of reducing undesired vibration and noises as compared with others that have a rotor with teeth on its circumferential surface. In addition, it has less inertia so that it has a high quality capable of responding faster. The magnetic component 5 comprises a first and second magnetic component portions 6 and 7 that are to be combined together, thus they are capable of receiving magnetic force independently, proving themselves to be more controllable with two-phase type. And also it is possible to construct a smaller manufacturing equipment, because the physical size of the magnetizing apparatus for the magnetic components can be determined on the basis of the size of the first and second magnetic component portions 6 and 7.
Description
- 1. Field of the Invention
- The present invention relates to a structure of a rotor in a stepping motor, widely used for paper-feeders in facsimiles and scanners in copying machines.
- 2. Description of the Related Art
- An example of prior art is a stepping motor having a rotor comprising a permanent magnet between two rotating components that are held by the rotor axis at an appropriate spacing, and one of the rotating component is magnetized as N-pole and the other as S-pole (see FIG. 4 in Japanese Patent Laid-open No. Hei 10-80124), or stepping motors having a rotor comprising a cylindrical permanent magnet with multi-polar magnetic parts arranged around the circumference thereof (see FIGS. 1 and 2 in the above-mentioned Japanese Patent), or a configuration as shown in FIGS. 14A and 14B.
- The stepping motor shown in FIG. 14A has a
stator yoke 42 in a housing 41, and enables arotor 44 to rotate bybearings coil 46 connected withlead wire 45 to an electric circuit (not shown). - The
rotor 44 includes arotor axis 47,rotor components rotor axis 47, andmagnet 49, as shown in FIGS. 14A and 14B. - Meanwhile, one of the prior art, for example, (as disclosed in FIG. 4 of the above-mentioned Japanese Patent), wherein a permanent magnet is provided between two rotor components, is apt to make undesired vibration and/or noises because such a structure has magnetic salient portions (teeth) on the circumferential portion. The vibration and noises are also problems found in a prior art shown in FIGS. 14A and 14B. With regard to the stepping motor having a rotor provided with a cylindrical permanent magnet with multi-polar magnetic parts arranged around the circumferential surface thereof (disclosed in FIGS. 1 and 2 of the above-mentioned Japanese Patent), this prior art is designed to eliminate vibration and noise problems.
- Though concerned conventional stepping motors have a cylindrical permanent magnet, they have only one cylindrical permanent magnet in their rotors, thereby not only applicable driving force would be limited to only three-phase type, but also the apparatus to magnetize the rotors must be larger because the axial length of the permanent magnet is usually long.
- Coping with above stated problems, the present invention is to provide a structure of a rotor in stepping motors capable of not only rotating much faster, but also eliminating undesired vibration and noises even under rotation at high speed.
- Another object of the present invention is to provide the structure of rotor capable of performing with two-phase type, and in addition, a simpler and more cost-effective motor manufacturing equipment can be built according
- According to a first aspect of the present invention, there is provided a structure of a rotor in a stepping motor having a rotor comprising magnetic component whose circumferential part is magnetized in multipole along the circumferential surface thereof, the stepping motor being capable of forcing the rotor to rotate by magnetic force provided between magnetic poles of the rotor and excited salient poles of a stator, characterized in that the magnetic component comprises two magnetic component portions each shaped as an approximate ring, and the two magnetic component portions are either combined with each other or set up separately at appropriate spacing inbetween.
- According to a second aspect of the present invention, in the first aspect, the two magnetic component portions have a plurality of N-poles and a plurality of S-poles, said N-poles and S-poles each being magnetized alternately at appropriate spacing inbetween, and the N-poles and S-poles are arranged such that contrary poles face each other.
- According to a third aspect of the present invention, there is provided a structure of a rotor in a stepping motor having a rotor comprising magnetic component magnetized in its radial direction, the stepping motor being capable of forcing the rotor to rotate by magnetic force provided between magnetic poles of the rotor and excited salient poles of a stator, characterized in that the magnetic component comprises two magnetic component portions each shaped as an approximate gear, and the two magnetic component portions have, on their circumferential surface, convex portions that extend in the axial direction and are disposed at appropriate spacing, and the two magnetic component portions are either combined with each other or set up separately at appropriate spacing inbetween.
- According to a fourth aspect of the present invention, in the third aspect, the convex portions are radially magnetized so that the convex portions on one magnetic component portion have the contrary pole to the convex portions on the other magnetic component portion, and said convex portions are so arranged that they are in aligned viewed in the axial direction.
- According to a fifth aspect of the present invention, in the third aspect:, the two magnetic component portions are magnetized with poles contrary to each other, and the two magnetic component portions have convex portions opposing to concave portions when viewed in the axial direction.
- In the accompanying drawings:
- FIG. 1 is a sectional view showing a stepping motor according to a first embodiment of the present invention;
- FIGS. 2A and 2B show a rotor of the stepping motor in FIG1, FIG. 2A is a perspective view showing the rotor whose two magnetic component portions are combined with each other in the axial direction, and FIG. 2B is a perspective view showing the rotor whose two magnetic component portions are arranged at an appropriate vacant spacing in the axial direction;
- FIGS. 3A and 3B show a stator yoke, FIG. 3A is a perspective view thereof, and FIG. 3B is a front view thereof;
- FIGS. 4A, 4B and4C show a stator yoke according to a second embodiment of the present invention, FIG. 4A is a perspective view thereof, FIG 4B is a sectional view taken along the line X-X in FIG. 4A, and FIG. 4C is a sectional view taken along the line Y-Y in FIG. 4A;
- FIG. 5 is a sectional view of the stator and the rotor taken along the line X-X in FIG. 4A;
- FIG. 6 is a sectional view of the stator and the rotor taken along the line Y-Y in FIG. 4A;
- FIGS. 7A and 7B show a rotor according to a third embodiment of the present invention, FIG. 7A is a perspective view showing the rotor whose two magnetic component portions are combined with each other in the axial direction, and FIG. 7B is a perspective view showing the rotor whose two magnetic component portions are arranged at an appropriate vacant spacing in the axial direction;
- FIGS. 8A and 8B show a rotor according to a fourth embodiment of the present invention, FIG. 8A is a perspective view showing the rotor whose two magnetic component portions are combined with each other in the axial direction, and FIG. 8B is a perspective view showing the rotor whose two magnetic component portions are arranged( at an appropriate vacant spacing in the axial direction;
- FIGS. 9A and 9B show a rotor according to a fifth embodiment of the present invention, FIG. 9A is a perspective view showing the rotor whose two magnetic component portions are combined with each other in the axial direction, and FIG. 9B is a perspective view showing the rotor whose two magnetic component portions are arranged at an appropriate vacant spacing in the axial direction;
- FIGS. 10A and 10B show a rotor according to a sixth embodiment of the present invention, FIG. 10A is a perspective view showing the rotor whose two magnetic component portions are combined with each other in the axial direction, and FIG. 10B is a perspective view showing the rotor whose two magnetic component portions are arranged at an appropriate vacant spacing in the axial direction;
- FIG. 11 is a sectional view showing the rotor in FIG. 9 or10 and a stator used for the rotor;
- FIG. 12 is a sectional view showing the rotor in FIG. 9 or10 and a stator used for the rotor;
- FIGS. 13A and 13B show a rotor of the stepping motor according to a seventh embodiment of the present invention, FIG. 13A is a perspective view showing the rotor whose two magnetic component portions are combined with each other in the axial direction, and FIG. 13B is a perspective view showing the rotor whose two magnetic component portions are arranged at an appropriate vacant spacing in the axial direction;
- FIG. 14A is a sectional view showing a conventional stepping motor; and
- FIG. 14B is a perspective view showing a rotor in the stepping motor in FIG. 14A.
- Referring to FIGS.1 to 3, a first embodiment of the present invention is described as follows.
- A stepping motor referred to as the first embodiment of the present invention has a
stator 3 equipped in ahousing 20, and enables arotor 2 to rotate around abearing 21 as shown in FIG 1, and therotor 2 comprises mainly arotor axis 4 capable of rotating freely as being held by thebearing 21, and amagnetic component 5 that held by therotor 4 by means of supporting portions (not shown) as shown in FIG 2. - The
magnetic component 5 comprisesmagnetic component portions magnetic component portions magnetic component portions magnetic component portion 6 and the other one at the right hand a secondmagnetic component portion 7. - At the respective circumferential surfaces of the first and second
magnetic component portions magnetic component portions - In this instance, the N-poles and S-poles of the first and second
magnetic component portions magnetic component portion 6 is juxtaposed next to an S-pole of thesecond component portion 7 when viewed from the viewing angle along theaxis 4 of the rotor. - As shown in FIGS. 3A and 3B the
stator 3 comprises an approximate-rectangular stator yoke 8 having a hole (whose reference numeral is omitted) at its central part, through which therotor 2 is inserted, and acoil 9 is wound around thestator yoke 8. Thecoil 9 is connected withlead wire 22 to an electric circuit (not shown). Thestator yoke 8 comprises a laminated sheet made of a plurality of thin steel plates. - A magnetic
salient portion 12 is provided at the top of eachleg 11 of the core located inside thestator yoke 8, and the magneticsalient portion 12 is facing towards thecoil 9. A plurality of tooth 13 (two teeth in this embodiment) are formed on the circumferential surface of the magneticsalient portion 12 around the circular surface of the magnetsalient portion 12. A gap (whose reference numeral is omitted) is formed between theteeth 13 and therotor 2. - Furthermore, the
stator 3 can be comprised of first and secondstator yoke components - The
coils 9 are provided correspondingly for the first and secondmagnetic component portions coil 9 and the firstmagnetic component portion 6, and also between thecoil 9 and the secondmagnetic component portion 7. The first and secondmagnetic component portions - The
magnetic component 5 of therotor 2 described beforehand in the first embodiment takes a ring formation so that the distribution curve of the magnetic flux density in the magnetic field is of sine wave. Hence the motor gives less vibration and noises than that have teeth on the circumferential surface of the rotor, and furthermore it has smaller inertia and thus able to perform with much faster response. - As the
magnetic component 5 is composed of the combination of the first and secondmagnetic component portions 6 and 7 (see FIG. 2A), each portion is able to receive magnetic force independently, thus resulting in good controllability of the motor as applied with two-phase type. As themagnetic component 5 comprises first and secondmagnetic component portions magnetic component portions - Referring now to FIGS.4 to 6, a second embodiment of the present invention is described as follows.
- With regard to the second embodiment, the
stator yoke 8 of thestator 3 is composed of twostator yoke components stator yoke components stator yoke component 14 and the other one at the right hand a secondstator yoke component 14. The first and secondstator yoke components - Since the first and second
stator yoke components magnetic component portions - As similar to the first embodiment, in the second embodiment stated above, this type of stepping motor according to the present invention is capable of preventing undesired vibration and noises, rotating with faster speed, being more controllable with two-phase type, making the manufacturing equipment smaller, and thus reducing the manufacturing cost.
- With regard to the second embodiment of the present invention, the steel plates can be prepared with only one type of die, because the first and second stator
yoke component portions - In examples of the first and second embodiment of the present invention, each shape of the first and second
magnetic component portions magnetic component portions - With regard to the third embodiment (see FIGS. 7A and 7B), the first and second
magnetic component portions - In the third embodiment, the first and second
magnetic component portions convex portions convex portion 6 a of the firstmagnetic component portion 6 and theconvex portion 7 a of themagnetic component portion 7 are magnetized in the radial direction, so that contrary poles face each other when viewed in the axial direction. In this embodiment, for example, theconvex portion 6 a of the firstmagnetic component portion 6 is magnetized as N-pole, and theconvex portion 7 a of themagnetic component portion 7 as S-pole. - The first and second
magnetic component portions convex portions convex portion 6 a (N-pole) of the firstmagnetic component portion 6 is juxtaposed next to a reentrant (concave) portion (whose reference numeral is omitted) between twoconvex portions 7 a (S-pole) of the secondmagnetic component portion 7, and the first and second magnetic component portions are combined in the axial direction (FIG. 7A), or disposed at a predetermined spacing E (FIG. 7B). - The third embodiment of the present invention is capable of doing a fine control over the motor performance with two-phase type, and also constructing of a smaller manufacturing equipment is possible by the same reason for the first and second embodiments of the present invention.
- With regard to the fourth embodiment of the present invention, slightly different from the third embodiment, it has modification that circular reentrant (concave)
portions 16 are formed at either side of the combined portion of the first and second magnetic component portions, as shown in FIGS. 8A and 8B. - The fourth embodiment of the present invention is capable of rotating much faster than the third embodiment because now that it is lighter as the circular reentrant (concave)
portion 16 is formed at either side of the combined portion of the first and second magnetic component portions. - In the third and fourth embodiments of the present invention, the
convex portions magnetic component portions convex portions convex portion 6 a (N-pole) of themagnetic component portion 6 is aligned withconvex portion 7 a (S-pole) of themagnetic component portion 7 in series in the axial direction), and both magnetic component portions are either combined each other or disposed at a predetermined spacing E. - Like the third embodiment, the fifth embodiment of the present invention is capable of doing a fine control over the motor performance with two-phase type, and also constructing a smaller manufacturing equipment is possible
- Furthermore, like the fourth embodiment, the sixth embodiment of the present invention is capable of rotating much faster than before because now that it is lighter as the circular reentrant (concave)
portion 16 is introduced into either side of the combined portion of the first and secondmagnetic component portions - In the third to sixth embodiments, the rotors are exemplified wherein the diameter of the first
magnetic component portion 6 which includes theconvex portion 6 a is the same as that of the secondmagnetic component 7 which includes theconvex portion 7 a, however, instead it is possible that the diameter of the firstmagnetic component portion 6 is different from that of the second magnetic component portion 7 (a seventh embodiment of the present invention). - According to the first and second aspects of the present invention, the magnetic component comprises two magnetic component portions magnetized in multipole on their circumferential surfaces, being either combined with each other or disposed at a predetermined spacing, and shaped as an approximate ring. Thus, the distribution curve of magnetic flux in the magnetic field is of sine wave, which means that this type of stepping motor prevents undesired vibration and noises more than other types that have teeth on the circumferential surfaces of their rotors. The type of stepping motor according to the present invention has; a smaller inertia and faster-response ability because the magnetic component in the rotor is ring-like.
- Since the magnetic component comprises two magnetic component portions being either combined with each other or arranged at an appropriate spacing, and the respective portions are capable of receiving magnetic force independently, thus resulting in better performance with regard to controllability with the two-phase type. In addition, the magnetizing apparatus can be smaller on the basis of the physical size of the two magnetic component portions, because the magnetic component comprises two magnetic component portions, thus constructing a smaller sized manufacturing equipment is possible.
- According to the third to fifth aspects of the present invention, the magnetic component comprises two magnetic component portions being either combined with each other or arranged at an appropriate spacing, and the respective portions are capable of receiving magnetic force independently, thereby resulting in better performance with regard to controllability with the two-phase type. The magnetizing apparatus can be smaller on the basis of the physical size of the two magnetic component portions, because the magnetic component comprises two magnetic component portions. Thus, it is possible to construct a smaller sized manufacturing equipment.
Claims (5)
1. A structure of a rotor in a stepping motor having a rotor comprising magnetic component whose circumferential part is magnetized in multipole along the circumferential surface thereof, said stepping motor being capable of forcing said rotor to rotate by magnetic force provided between magnetic poles of said rotor and excited salient poles of a stator, characterized in that said magnetic component comprises two magnetic component portions each shaped as an approximate ring, and said two magnetic component portions are either combined with each other or set up separately at an appropriate spacing between them.
2. A structure of a rotor in a stepping motor according to claim 1 wherein said two magnetic component portions have a plurality of N-poles and S-poles arranged alternately at appropriate spacing inbetween, said magnetic components are arranged so that contrary poles face each other.
3. A structure of a rotor in a stepping motor having a rotor comprising magnetic component magnetized in its radial direction, said stepping motor being capable of forcing said rotor to rotate by magnetic force provided between magnetic poles of said rotor and excited salient poles of a stator, characterized in that said magnetic component comprises two magnetic component portions each shaped as an approximate gear, and said two magnetic component portions have, on their circumferential surface, convex portions that extend in the axial direction and are disposed at appropriate spacing, and said two magnetic component portions are either combined with each other or set up separately at appropriate spacing between them.
4. A structure of a rotor in a stepping motor according to claim 3 , wherein said convex portions are radially magnetized so that said convex portions on one magnetic component portion have the opposite pole to said convex portions on the other magnetic component portion, and said convex portions are so arranged that they are in aligned arrangement, when viewed in the axial direction.
5. A structure of a rotor in a stepping motor according to claim 3 wherein said two magnetic component portions are magnetized with poles contrary to each other and,
wherein said two magnetic component portions have convex portions opposing to concave portions when viewed in the axial direction.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US10/394,159 US6958556B2 (en) | 2000-09-28 | 2003-03-24 | Structure of rotors in stepping motors |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2000296600A JP2002112521A (en) | 2000-09-28 | 2000-09-28 | Rotor construction for stepping motor |
JP2000-296600 | 2000-09-28 |
Related Child Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US10/394,159 Continuation US6958556B2 (en) | 2000-09-28 | 2003-03-24 | Structure of rotors in stepping motors |
Publications (1)
Publication Number | Publication Date |
---|---|
US20020036437A1 true US20020036437A1 (en) | 2002-03-28 |
Family
ID=18778853
Family Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US09/960,927 Abandoned US20020036437A1 (en) | 2000-09-28 | 2001-09-25 | Structure of roters in stepping motors |
US10/394,159 Expired - Lifetime US6958556B2 (en) | 2000-09-28 | 2003-03-24 | Structure of rotors in stepping motors |
Family Applications After (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US10/394,159 Expired - Lifetime US6958556B2 (en) | 2000-09-28 | 2003-03-24 | Structure of rotors in stepping motors |
Country Status (3)
Country | Link |
---|---|
US (2) | US20020036437A1 (en) |
EP (1) | EP1193846A1 (en) |
JP (1) | JP2002112521A (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20030201678A1 (en) * | 2002-04-26 | 2003-10-30 | Shih-Ming Huang | Rotor structure of permanent magnet stepping motor |
US7183675B2 (en) | 2002-04-26 | 2007-02-27 | Delta Electronics, Inc. | Permanent magnet stepping motor |
Families Citing this family (7)
Publication number | Priority date | Publication date | Assignee | Title |
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JP4000144B2 (en) * | 2004-12-15 | 2007-10-31 | 山洋電気株式会社 | Rotor for hybrid type stepping motor and manufacturing method thereof |
US7402932B2 (en) * | 2005-01-31 | 2008-07-22 | Applegate Rodney W | Apparatus and system for driving a fan using a linear induction motor |
JP2007043763A (en) * | 2005-07-29 | 2007-02-15 | Nidec Sankyo Corp | Process for manufacturing rotor magnet, and motor |
JP2009136089A (en) * | 2007-11-30 | 2009-06-18 | Mitsumi Electric Co Ltd | Rotor for stepping motors, and stepping motor |
JP2013009560A (en) * | 2011-06-27 | 2013-01-10 | Minebea Co Ltd | Hybrid stepping motor |
CN104319060B (en) * | 2014-09-17 | 2016-08-24 | 徐州通用高新磁电有限公司 | A kind of p-m rotor sine magnetization method and device |
JP7415487B2 (en) * | 2019-11-28 | 2024-01-17 | セイコーエプソン株式会社 | axial gap motor |
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USRE25445E (en) * | 1963-09-17 | fredrickson | ||
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US3671841A (en) * | 1970-05-01 | 1972-06-20 | Tri Tech | Stepper motor with stator biasing magnets |
US3801842A (en) * | 1972-06-27 | 1974-04-02 | Ncr | Stepping motor |
DE2337905A1 (en) * | 1973-07-26 | 1975-02-13 | Gerhard Berger Fabrikation Ele | SELF-STARTING SYNCHRONOUS MOTOR WITH PERMANENT MAGNETIC RUNNING |
US4009406A (en) * | 1975-11-25 | 1977-02-22 | Tokuzo Inariba | Synchronous micromotor with a permanent magnet rotor |
US4406958A (en) * | 1981-04-06 | 1983-09-27 | The Superior Electric Company | Stepping motors with disc magnet |
JPS59135087U (en) * | 1983-02-26 | 1984-09-10 | シナノケンシ株式会社 | Permanent magnet step motor |
JPS59204461A (en) * | 1983-05-09 | 1984-11-19 | Japan Servo Co Ltd | Permanent magnet type stepping motor |
JPS6070941A (en) * | 1983-09-28 | 1985-04-22 | Tokuzo Inariba | Pole teeth group structure for small-sized motor and manufacture thereof |
JPS60241759A (en) * | 1984-05-14 | 1985-11-30 | Matsushita Electric Works Ltd | Synchronous motor |
JPS6135152A (en) * | 1984-07-25 | 1986-02-19 | Matsushita Electric Works Ltd | Stepping motor |
JPS61150656A (en) * | 1984-12-25 | 1986-07-09 | Matsushita Electric Ind Co Ltd | Stepping motor |
JPS62185481U (en) * | 1986-05-13 | 1987-11-25 | ||
JPH01103151A (en) * | 1987-10-16 | 1989-04-20 | Olympus Optical Co Ltd | Stepping motor |
US5384506A (en) * | 1992-05-29 | 1995-01-24 | Canon Kabushiki Kaisha | Stepper motor |
JPH08214519A (en) * | 1995-02-06 | 1996-08-20 | Akira Chiba | Both-saliency motor-generator using permanent magnet |
JPH1080124A (en) | 1996-08-30 | 1998-03-24 | Japan Servo Co Ltd | Permanent magnet type rotating electric machine |
AU1092799A (en) * | 1997-10-16 | 1999-05-03 | Steven L. Sullivan | Generators and transformers with toroidally wound stator winding |
JPH11289737A (en) * | 1998-04-03 | 1999-10-19 | Oriental Motor Co Ltd | Hybrid stepping motor |
JP2000324769A (en) * | 1999-05-13 | 2000-11-24 | Matsushita Electric Ind Co Ltd | Stepping motor |
-
2000
- 2000-09-28 JP JP2000296600A patent/JP2002112521A/en active Pending
-
2001
- 2001-09-25 US US09/960,927 patent/US20020036437A1/en not_active Abandoned
- 2001-09-27 EP EP01810941A patent/EP1193846A1/en not_active Withdrawn
-
2003
- 2003-03-24 US US10/394,159 patent/US6958556B2/en not_active Expired - Lifetime
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20030201678A1 (en) * | 2002-04-26 | 2003-10-30 | Shih-Ming Huang | Rotor structure of permanent magnet stepping motor |
US7183675B2 (en) | 2002-04-26 | 2007-02-27 | Delta Electronics, Inc. | Permanent magnet stepping motor |
Also Published As
Publication number | Publication date |
---|---|
US20030184166A1 (en) | 2003-10-02 |
EP1193846A1 (en) | 2002-04-03 |
JP2002112521A (en) | 2002-04-12 |
US6958556B2 (en) | 2005-10-25 |
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AS | Assignment |
Owner name: MINEBEA CO., LTD., JAPAN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:KUROSAWA, SOICHI;KANAZAWA, AKIO;YOSHIDA, NAOHIRO;REEL/FRAME:012209/0745 Effective date: 20010920 |
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STCB | Information on status: application discontinuation |
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