JPH11168862A - Hysteresis motor and image-forming device using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase magnetic flux passing through a rotor ring and to improve torque, by generating, using a second group of stators, rotary magnetic field in the same direction with the same period as those of rotary magnetic field that affects the first annular ring of the rotor ring being formed by a hysteresis material. SOLUTION: A rotor 32 is sealed to a rotary shaft 32b where a rotor ring 32a of a hysteresis material is mounted to a casing 31 via bearings 35a and 35b so that it can be rotated freely. A first group of stators 330 are provided with a plurality of stators 33 that give rotary magnetic field to the rotor ring 32a from an upper surface side. A second group of stators 340 give rotary magnetic field with the same direction and period as those of rotary magnetic field where a first group of stators 330 are generated to the rotor ring 32a. Then, the same number of stators 34 as the stators of the first group of stators 330 are provided. Therefore, by arranging a group of stators 340 while they oppose the other main surface as well as one main surface of the rotor ring 32a, the total amount of magnetic flux passing through the rotor ring 32a increases and hence torque can be increased by that amount.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hysteresis motor having improved torque characteristics and an image forming apparatus such as a copying machine or a printer using the motor.

[0002]

2. Description of the Related Art For example, a photosensitive drum of a copying machine or the like is exposed to laser light at a constant period in a main scanning direction while being rotated in a sub-scanning direction to form an electrostatic latent image. If the rotation speed is unstable, the intervals between the scanning lines become uneven and the quality of the finished image deteriorates. Therefore, high stability is required for the rotation speed. Although a high rotation accuracy is required, a stepping motor having relatively high braking performance is often used recently. However, although the stepping motor has a high overall rotation accuracy, the rotor is rotated by one step angle while repeating the start / stop operation every time one input pulse is input. When viewed in units of one step angle, a minute vibration is generated in the motor itself due to a change in acceleration from the start to the stop, and this appears as slight rotation unevenness.

Here, a hysteresis motor is known as a motor having even smaller rotational unevenness, and its use as a driving source for a photosensitive drum is conceivable.

[0004]

However, the conventional hysteresis motor generally has a small torque due to its characteristics as compared with other motors of the same size. Is not suitable for driving a photosensitive drum requiring a relatively large torque.

In view of the above problems, the present invention improves the torque of the hysteresis motor and uses the hysteresis motor with the improved torque as a drive source for the photosensitive drum, thereby obtaining a stable finished image. It is an object to provide an image forming apparatus.

[0006]

In order to achieve the above object, a hysteresis motor according to the present invention comprises a rotor ring formed of a hysteresis material and a rotating magnetic field applied to a first annular region of the rotor ring. And a second stator generating a rotating magnetic field having the same direction and the same cycle as the rotating magnetic field exerted on the second annular region of the rotor ring.
And a stator group.

Further, the rotor ring is a disk-shaped rotor ring, and the first stator group is disposed so as to face one main surface of the rotor ring, and the second stator group is provided. The child group is characterized by being arranged facing the other main surface. Further, the rotor ring is a disk-shaped rotor ring, and a first stator group and a second stator group are arranged to face the same main surface of the rotor ring. And

[0008] Further, the rotor ring is a cylindrical rotor ring, and the first stator group is disposed so as to face an inner peripheral surface of the rotor ring, and the second stator group is provided. The child group is provided so as to face the outer peripheral surface of the rotor ring. In addition, the rotor ring includes:
Disc-shaped first rotor ring and cylindrical second
And the first stator group comprises:
The second stator group is disposed on at least one of the inner and outer peripheral surfaces of the second rotor ring portion. It is characterized by being arranged facing each other.

Further, the rotor ring has a hollow portion at an intermediate portion in a thickness direction thereof, and a magnetic body having a higher magnetic permeability than the hysteresis material is arranged in the hollow portion.
Further, a part of the hollow portion is open, and the magnetic body is inserted from the open portion into the hollow portion so as not to contact the rotor ring, and is arranged.

[0010] The magnetic material is provided integrally with the rotor ring. Also,
The rotor ring portion corresponding to either the first stator group or the second stator group is made of a non-magnetic conductive material instead of the hysteresis material.

According to another aspect of the present invention, there is provided an image forming apparatus including a photosensitive drum on which an electrostatic latent image is formed while being rotated. Wherein the hysteresis motor is used.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to a single-color digital copying machine (hereinafter simply referred to as "copier").
An example in which the present invention is applied will be described. FIG. 1 is a diagram illustrating an entire configuration of a copying machine according to an embodiment. The copying machine includes an image reader unit 1 for reading a document image and a printer unit 2 for printing the read image on copy paper and reproducing the image.
It is composed of

The image reader unit 1 is a well-known one that scans a document image placed on a platen glass and converts the image into an electric signal to obtain image data. The image data obtained by the image reader unit 1
The digital signal is subjected to / D conversion and further subjected to necessary processing such as shading correction, density conversion, and edge enhancement, and then output as a laser diode drive signal.

The printer section 2 forms an image on copy paper by an electrophotographic method, and includes an exposure scanning section 4, an image processing section 5, a paper feeding section 6, and the like. The exposure scanning unit 4 includes a laser diode 7, a polygon mirror 8, a scanning lens 9, and the like. The laser diode 7 receives the drive signal from the control unit 3 and emits light modulated laser light. The emitted laser light is reflected and deflected by a mirror surface of a polygon mirror 8 that is driven to rotate at a constant speed, passes through a scanning lens 9, and exposes and scans the surface of the photosensitive drum 10 of the image processing unit 5.

The image processing unit 5 includes the photosensitive drum 1
0, a cleaner 11, an eraser lamp 12, a charging charger 13, a developing unit 14, and the like are arranged. The photoreceptor drum 10 is uniformly charged by a charging charger 13 after the residual toner on the photoreceptor surface is removed by a cleaner 11 before receiving the above-mentioned exposure, and further irradiated by an eraser lamp 12 to remove electricity. When exposure is performed in such a uniformly charged state, an electrostatic latent image is formed on the photoconductor on the surface of the photoconductor drum 10.

The electrostatic latent image is developed by the developing device 14 and visualized as a toner image. The toner image is fed from the paper feeding unit 6 in synchronization with the image forming operation, is transferred onto a copy sheet conveyed by the conveyance belt 17, is thermally fixed in the fixing device 15, and then is fixed to the discharge tray 16. Is discharged upward, thereby completing the image formation based on the image data of the document.

FIG. 2 is a perspective view showing a configuration of a drive system of the conveyor belt 17 and the photosensitive drum 10. As shown in FIG. The transport belt 17 is stretched by a driving roller 18 and a supporting roller 19, and the driving roller 18 is driven by a driving mechanism 20 including a DC motor, a speed reducer, and the like. It is controlled by the control unit 3 (FIG. 1) so as to be conveyed at “system speed”.

The photosensitive drum 10 is directly connected to the rotation axis AX of the hysteresis motor HM, and the hysteresis motor HM is also controlled such that the peripheral speed of the photosensitive drum 10 matches the system speed. The hysteresis motor HM and its rotation axis AX are respectively supported by a frame and a bearing member (not shown).

Hereinafter, the hysteresis motor HM will be described for each type. (Type 1) FIG. 3A is a full sectional view showing a schematic configuration of the hysteresis motor 30 according to Type 1. FIG.
FIG. 3B is a sectional view taken along line AA in FIG. The hysteresis motor 30 is an axial gap type motor having a gap between the stator and the rotor in the axial direction of the rotation shaft, and includes an upper bracket 31a, a lower bracket 31
The rotor 32, the first stator group 330, and the second stator group 340 are provided on the casing 31 composed of the frame 31b and the frame 31c.
Are stored.

The rotor 32 is formed by fixing a rotor ring 32a made of a disc-shaped hysteresis material to a rotating shaft 32b.
It is rotatably attached to the casing 31 via 5b. The first stator group 330 is for applying a rotating magnetic field to the rotor ring 32a from the upper surface side,
It is composed of a plurality of stators 33 (eight in the illustrated example). Each stator 33 is configured by winding a stator winding 33b around a stator core 33a. The stator core 33b is formed on the upper flange 31a by a circle centered on the axis of the rotating shaft 32b. It is erected at a substantially equal pitch on the circumference.

The second stator group 340 applies a rotating magnetic field having the same direction and the same cycle as the rotating magnetic field generated by the first stator group 330 to the rotor ring 32a from the lower surface side. There are the same number of stators 34 as the number of stators in the first stator group 330. Each stator 34 is configured such that a stator winding 34b is wound around a stator core 34a, and the respective stator cores 34b are connected to the lower flange 31b.
In addition, they are erected at a substantially equal pitch on a circle having the same diameter as the above.

As described above, the type 1 hysteresis motor 30
In the above, the stator group is arranged so as to face not only one main surface of the rotor ring but also the other main surface, so that the total amount of magnetic flux passing through the rotor ring increases, and the torque increases accordingly. . As a means for increasing the amount of magnetic flux passing through the rotor ring, it is conceivable to increase the number of stators arranged to face the same main surface. In this case, however, on one circumference (the axis of the rotating shaft) The distance between the stators becomes shorter due to the arrangement on the circumference around the center). That is, the path length (magnetic path length) from the magnetic flux emitted from one stator to the corresponding stator is shortened. Therefore, if the number of stators used for one motor is the same, providing the stators on both main surface sides of the rotor ring as in the above-described type 1 increases the distance between the stators and the magnetic path. Since the length can be earned by that amount, the volume through which the magnetic flux in the rotor ring passes increases,
This is advantageous for increasing the torque. (Type 2) FIG. 4A is a half sectional view showing a schematic configuration of a hysteresis motor 40 according to Type 2.

The type 2 hysteresis motor 40 has basically the same configuration as the type 1 except that the shape of the rotor ring is different and a magnetic material is added as a constituent member. Therefore, common parts are denoted by the same reference numerals, and description thereof will be omitted, and different parts will be mainly described. The type 2 rotor ring 42 is a type 1 disk-shaped rotor ring 32.
a has a shape in which a hollow portion is provided at an intermediate portion in the thickness direction.
The hollow portion is a space formed by cutting off a middle portion in the thickness direction of the type 1 rotor ring with a constant width except for the vicinity of the inner peripheral portion, and is opened at the outer peripheral portion of the rotor ring.

The magnetic pieces 46a and 46b are inserted through the openings, and one ends of the magnetic pieces 46a and 46b are fixed to the frame 31d. Magnetic pieces 46a, 46
b is a fan-shaped plate body as shown in the sectional view taken along the line BB in FIG. 4B, and is provided in a dovetail groove provided in the frame 31d.
Part of it is inserted and attached. The magnetic pieces 46a and 46b are made of a material having a higher magnetic permeability than the hysteresis material forming the rotor ring 42, for example, an electromagnetic soft iron or a silicon steel plate.

As described above, the type 2 hysteresis motor 40
Since the magnetic material is provided as described above, compared with the case where the magnetic material piece is not provided as shown in FIG.
As shown in FIG. 5B, the magnetic material pulls the magnetic flux, and the magnetic flux passes deep inside the rotor ring, so that the volume through which the magnetic flux in the rotor ring passes increases. Greater torque is obtained.

In the above example, the magnetic pieces 46a, 4a
6b is fixed to the frame 31d and is provided so as not to contact the rotor ring 42. However, the present invention is not limited to this. As shown in FIG. May be provided integrally. In this case, the magnetic piece 47 also rotates integrally with the rotor ring 42. This makes it easy to assemble the hysteresis motor. (Type 3) FIG. 7A is a full sectional view showing a schematic configuration of a hysteresis motor 50 according to Type 3. FIG.
(B) is a sectional view taken along line CC in FIG. 7 (a).

The components constituting the hysteresis motor 50 are basically the same as those of the type 1 hysteresis motor 30, so that the description thereof will be omitted.
Like the type 1 hysteresis motor 30 (FIG. 3), the hysteresis motor 50 is also an axial gap type motor having an air gap between the stator and the rotor in the axial direction of the rotating shaft. Although the rotor ring 52a made of a hysteresis material described above is provided, the arrangement of the stator is different from that of the type 1 hysteresis motor 30.

That is, the type 1 hysteresis motor 30
In the above, the stator group is arranged so as to face both main surfaces of the rotor ring 32a. However, in type 2, as shown in FIG. 7A, both stator groups have one main surface (the lower surface in the illustrated example). ). As shown in FIG. 7B, a plurality of stators 53 forming the first stator group 530 are provided.
(Four in the illustrated example) are arranged on the circumference around the axis of the rotating shaft 52b at a substantially equal pitch near the outer periphery of the rotor ring 52a, and constitute a second stator group 540. A plurality of stators 54 (four in the illustrated example) are arranged on the concentric circle at a substantially equal pitch near the inner periphery of the rotor ring 52a. It should be noted that the stator 53 constituting the first stator group 530 is
And the stator 54 constituting the second stator group 540 are arranged so as to be shifted by a half pitch in the circumferential direction.

The first stator group 530 includes the rotor ring 5
The second stator group 540 applies a rotating magnetic field having the same direction and the same cycle as the rotating magnetic field to a region near the inner periphery of the rotor ring 52a. It is to exert. In addition, the first stator group 530 and the second stator group 540 are separated by a cylindrical magnetic shielding member 58 in order to prevent interference between the generated magnetic fields. The magnetic shielding member 58 is formed of a ferromagnetic material having a high magnetic permeability, for example, a metal plate such as iron.

As described above, the type 3 hysteresis motor 50
According to the above, since the stator group is arranged on one main surface of the rotor ring in a double manner, the total amount of magnetic flux passing through the rotor ring increases as compared with the case where the stator group is arranged only in a single manner. The torque increases accordingly. In addition, the first stator group and the second stator group are arranged so as to be shifted by a half pitch, but the present invention is not limited to this, and the first stator group and the stator 53 constituting the first stator group are not shifted. The stators 54 constituting the two stator groups may be arranged to face each other with the magnetic shielding member 58 interposed therebetween. (Type 4) FIG. 8A is a full sectional view showing a schematic configuration of a hysteresis motor 60 according to Type 4.
FIG. 9B is a sectional view taken along line DD in FIG.

The hysteresis motors of the type described above are all axial gap type motors having a gap between the stator and the rotor in the axial direction of the rotating shaft. This is a type of motor having an air gap between the stator and the rotor in a direction perpendicular to the rotation axis, and has a rotor ring 62a having a cylindrical shape.

The rotor ring 62a has a rotating shaft 62b.
And the rotating shaft 62b is
Through the bearings 65a and 65b, the upper bracket 61a,
It is rotatably attached to a casing 61 composed of a lower bracket 61b and a frame 61c. A first stator group 630 is provided inside the rotor ring 62a, and a second stator group 640 is provided outside the rotor ring 62a.

The first stator group 630 includes the rotor ring 6
2a is for applying a rotating magnetic field to the inner peripheral surface from the inner peripheral surface side, and includes a plurality of stators 63 (in the illustrated example, 4a).
Individual). Each stator 63 is configured by winding a stator winding 63b around a stator iron core 63a, and is arranged at a substantially equal pitch on a circumference centered on the axis of the rotating shaft 62b.
The second stator group 640 is for applying a rotating magnetic field having the same direction and the same cycle as the rotating magnetic field generated by the first stator group 630 to the rotor ring 62a from the outer peripheral surface side, The first stator group 630 includes the same number of stators 64 as the number of stators. Each stator 64 is formed by winding a stator winding 64b around a stator iron core 64a, and the first stator group 630 is arranged on a concentric circle via a rotor ring 62a. It is arranged at a position facing each stator 63.

As described above, the type 4 hysteresis motor 60
In this case, since the stator group is arranged so as to face not only the outer peripheral surface but also the inner peripheral surface of the rotor ring, the total amount of magnetic flux passing through the rotor ring increases, and the torque increases accordingly. Note that the stator 33 constituting the first stator group 330 and the second
As shown in FIG. 9, the stators 34 constituting the stator group 340 may be shifted from each other by a half pitch in the circumferential direction.

Further, a magnetic material (magnetic material piece) may be provided as in the type 2 motor. That is, a hollow portion may be provided at the middle portion in the thickness direction of the cylindrical rotor ring 62a, and the magnetic material may be disposed in the hollow portion. in this case,
The hollow portion is a space formed by cutting off a middle portion in the thickness direction of the rotor ring 62a with a fixed width except for the vicinity of the upper end or lower end, and is opened at the lower end or upper end of the rotor ring. It is formed to be. Then, a cylindrical magnetic body having a width smaller than the predetermined width is provided on the lower bracket 61b or the upper bracket 61a, and when assembling, the magnetic body is inserted into the hollow portion. Further, the magnetic body may be provided integrally with the rotor ring. (Type 5) FIG. 10A is a full sectional view showing a schematic configuration of a hysteresis motor 70 according to Type 5, and FIG.
FIG. 11B is a sectional view taken along line FF in FIG.

The hysteresis motor 70 is of the type 1
3 to 7 (FIGS. 3 to 7) having a gap between the stator and the rotor in the axial direction of the rotating shaft;
As shown in FIGS. 8 and 9, the motor is a combination of a motor having a space between the stator and the rotor in a direction perpendicular to the rotation axis. As shown in FIG.
The rotor ring 72a of the hysteresis motor 70
It is composed of a rotor ring portion 721 having a disk shape and a rotor ring portion 722 having a cylindrical shape. The rotor ring 72a is fixed to a rotating shaft 72b, and the rotating shaft 72b is rotatably attached to a casing 61 composed of an upper bracket 71a, a lower bracket 71b, and a frame 71c via bearings 75a, 75b. ing.

Below the disk-shaped rotor ring 721, a first stator group 730 is provided.
A second stator group 740 is provided inside 2.
The first stator group 730 is for applying a rotating magnetic field to the rotor ring portion 721 from the lower surface side, and includes a plurality of stators 73 (four in the illustrated example). Each stator 73 is configured such that a stator winding 73b is wound around a stator core 73a, and each stator core 73b is formed on a lower flange 71b by a circle centered on the axis of a rotating shaft 72b. It is erected at a substantially equal pitch on the circumference.

The second stator group 740 applies a rotating magnetic field having the same direction and the same cycle as the rotating magnetic field generated by the first stator group 730 to the rotor ring portion 722 from the inner peripheral surface side. And the same number of stators 74 as the number of stators in the first stator group 730. Each stator 74 is configured such that a stator winding 74b is wound around a stator core 74a, and a half pitch with respect to the first stator group 730 at a substantially equal pitch on a circumference concentric with the above. It is provided on the upper bracket 71a shifted by the pitch.

As described above, the type 5 hysteresis motor 70
Then, the disk-shaped rotor ring 72
1 and a cylindrical rotor ring portion 722, and a driving force is obtained by applying a rotating magnetic field to each of the rotor ring portions 722. Therefore, compared with a case where only a single rotor ring portion is provided. , Large torque can be obtained. In the above example, the stator group is arranged on the lower surface side of the rotor ring portion 721, but may be arranged on the upper surface side. Furthermore, both sides may be arranged.

In the above example, the rotor ring 72
Although the stator group is arranged on the inner peripheral surface side of 2, it may be arranged on the outer peripheral surface side. Further, both peripheral surfaces may be arranged. In the above example, the first stator group and the second
Are shifted from each other by a half pitch, but the present invention is not limited to this, and they may be arranged without being shifted. (Type 6) FIG. 11A is a full sectional view showing a schematic configuration of a hysteresis motor 80 according to Type 6. FIG.
FIG. 12B is a sectional view taken along line GG in FIG.

The type 6 hysteresis motor 80 has basically the same configuration as the type 4 hysteresis motor 60 shown in FIG. 8, except that the material of the rotor ring is partially different. Therefore, common parts are denoted by the same reference numerals, and description thereof will be omitted, and different parts will be mainly described. The rotor ring 82 of the hysteresis motor 80 is formed by enlarging the inner diameter of the cylindrical rotor ring 62a of the hysteresis motor 60 (FIG. 8), and adding a non-magnetic and conductive material to the space formed by expanding the inner diameter. For example, it has a structure in which a cylindrical member 822 made of aluminum or the like is inserted. That is, the rotor ring 82 has a cylindrical shape having a two-layer structure including a rotor ring portion 821 formed on the outer periphery side with a hysteresis material and a rotor ring portion 822 formed on the inner periphery side with a nonmagnetic / conductive material. doing.

Therefore, the second stator group 640 and the rotor ring 821 function as a hysteresis motor,
The first stator group 630 and the rotor ring 822 function as an induction motor. Thus, the first stator group 63
By replacing the material constituting the rotor ring portion corresponding to 0 with a non-magnetic and conductive material instead of the hysteresis material, a part of the motor functions as an induction motor, and a single fixed A larger torque can be obtained as compared with a hysteresis motor having only a child group and a rotor ring.

In the above example, the outer peripheral side is made of a hysteresis material, and the inner peripheral side is made of a non-magnetic and conductive material. However, the present invention is not limited to this.
The inner peripheral side may be made of a hysteresis material with a conductive material. Further, in the above example, the hysteresis motor having the cylindrical rotor ring was used,
Hysteresis motors of types 1 and 3 having a disk-shaped rotor ring, and type 5 hysteresis motors having a rotor ring in which a cylindrical rotor ring and a disk-shaped rotor ring are combined. It may be targeted. At this time, in the case of the type 1 motor, the rotor ring 32a is formed by making the disk-shaped rotor ring 32a half the thickness, and sticking the same shape formed of a non-magnetic and conductive material to the rotor ring. I do. In the case of the type 3 motor, the radially outer peripheral side corresponding to the first stator group 530 or the radially inner peripheral side corresponding to the second stator group 540 of the rotor ring 52a is deleted. A member made of a non-magnetic / conductive material having the same shape as that of the rotor ring is fitted into the rotor ring. With a type 5 motor, the rotor ring 7
Either one of the rotor 21 and the rotor ring portion 722 is formed of a nonmagnetic / conductive material.

[0044]

As described above, according to the hysteresis motor according to the present invention, the first stator group for generating a rotating magnetic field exerting on the first annular region of the rotor ring formed of hysteresis material, and the rotor A second stator group for generating a rotating magnetic field exerted on the ring second annular region.
Compared to a hysteresis motor having only a single stator group, the total amount of magnetic flux passing through the rotor ring increases, and the torque increases accordingly.

Further, the first stator group is arranged to face one main surface of the disk-shaped rotor ring, and the second stator group is arranged to face the other main surface. Compared to the case where the stator group is arranged facing only the main surface of
Since the total amount of magnetic flux passing through the rotor ring increases, the torque increases accordingly. Further, since the first stator group and the second stator group are arranged to face the same main surface of the disk-shaped rotor ring, hysteresis in which only a single stator group is arranged is provided. Since the total amount of magnetic flux passing through the rotor ring increases as compared with the motor, the torque increases accordingly.

Also, since the first stator group is arranged to face the inner peripheral surface of the cylindrical rotor ring and the second stator group is arranged to face the outer peripheral surface, only one of the peripheral surfaces is provided. Compared with the case where the stator group is not disposed facing the rotor ring, the total amount of magnetic flux passing through the rotor ring increases, and the torque increases accordingly. In addition, since the rotor ring includes the first rotor ring portion having a disk shape and the second rotor ring portion having a cylindrical shape, the rotor ring includes only a single rotor ring portion. A larger torque can be obtained as compared with the conventional one.

In the middle part of the rotor ring in the thickness direction,
Since a magnetic material with higher permeability than the hysteresis material that forms the rotor ring is arranged, the magnetic flux from the stator group is pulled by the magnetic material, and the magnetic flux passes deep inside the rotor ring Therefore, since the volume of the portion of the rotor ring through which the magnetic flux passes also increases, a larger torque can be obtained.

Since the material constituting the rotor ring portion corresponding to either the first stator group or the second stator group is made of a non-magnetic and conductive material instead of the hysteresis material, The portion of the non-magnetic and conductive material of the child ring and the corresponding stator group function as an induction motor, and the torque is improved. Since any one of the above-described hysteresis motors is used as a drive source of the photosensitive drum of the image forming apparatus, the photosensitive drum can be driven, and a stable finished image can be obtained due to its characteristics such as small rotation unevenness.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a copying machine according to an embodiment of the present invention.

FIG. 2 is a perspective view illustrating a configuration of a photosensitive drum and a drive unit of a conveyor belt in the copying machine.

FIG. 3A is a longitudinal sectional view showing an embodiment of a hysteresis motor. (B) is A · A in (a).
It is a line sectional view.

FIG. 4A is a half sectional view showing an embodiment of a hysteresis motor. (B) is BB in (a).
It is a line sectional view.

FIG. 5A is a diagram illustrating a state of a magnetic flux around a rotor ring. (B) is a figure which shows the mode of the magnetic flux around a rotor ring.

FIG. 6 is a half sectional view showing an embodiment of a hysteresis motor.

FIG. 7A is a longitudinal sectional view showing an embodiment of a hysteresis motor. (B) shows C · C in (a).
It is a line sectional view.

FIG. 8A is a longitudinal sectional view showing an embodiment of a hysteresis motor. (B) shows D · D in (a).
It is a line sectional view.

FIG. 9A is a longitudinal sectional view showing an embodiment of a hysteresis motor. (B) shows EE in (a).
It is a line sectional view.

FIG. 10A is a longitudinal sectional view showing an embodiment of a hysteresis motor. (B) shows F · in (a).
It is an F line sectional view.

FIG. 11A is a longitudinal sectional view illustrating an embodiment of a hysteresis motor. (B) shows G · in (a).
It is G sectional drawing.

[Explanation of symbols]

30, 40, 50, 60, 70, 80 Hysteresis motors 32a, 42, 52a, 62a, 72a, 82 Rotor rings 46a, 46b, 47 Magnetic bodies 330, 530, 630, 730 First stator group 340, 540 , 640, 740 Second stator group 721, 722 Rotor ring portion 822 Rotor ring portion made of non-magnetic and conductive material

Claims (10)

[Claims] 1. A rotor ring formed of a hysteresis material, a first stator group for generating a rotating magnetic field exerting on a first annular region of the rotor ring, and a second annular ring of the rotor ring A second stator group for generating a rotating magnetic field having the same direction and the same cycle as the rotating magnetic field exerted on a region. 2. The rotor ring is a disk-shaped rotor ring, wherein the first stator group is disposed so as to face one main surface of the rotor ring, and wherein the second stator group is provided. 2. The hysteresis motor according to claim 1, wherein the child group is arranged to face the other main surface. 3. The rotor ring is a disk-shaped rotor ring, and a first stator group and a second stator group are arranged to face the same main surface of the rotor ring. The hysteresis motor according to claim 1, wherein: 4. The rotor ring is a cylindrical rotor ring, wherein the first stator group is disposed so as to face an inner peripheral surface of the rotor ring, and wherein the second stator group is provided. 2. The hysteresis motor according to claim 1, wherein the child group is disposed so as to face an outer peripheral surface of the rotor ring. 5. The rotor ring has a disk-like first shape.
The first stator group is disposed so as to face at least one main surface of the first rotor ring portion. The hysteresis motor according to claim 1, wherein the second stator group is disposed so as to face at least one of the inner and outer peripheral surfaces of the second rotor ring portion. 6. The rotor ring according to claim 2, wherein the rotor ring has a hollow portion at an intermediate portion in a thickness direction thereof, and a magnetic material having a higher magnetic permeability than the hysteresis material is disposed in the hollow portion. The hysteresis motor as described. 7. The magnetic device according to claim 1, wherein a part of the hollow portion is open, and the magnetic body is inserted from the open portion into the hollow portion so as not to contact the rotor ring. Item 7. A hysteresis motor according to Item 6. 8. The hysteresis motor according to claim 6, wherein the magnetic body is provided integrally with the rotor ring. 9. A material constituting a rotor ring portion corresponding to one of the first stator group and the second stator group is made of a nonmagnetic conductive material instead of the hysteresis material. The hysteresis motor according to claim 1, wherein: 10. An image forming apparatus provided with a photoconductive drum on which an electrostatic latent image is formed while being rotated, wherein the driving source of the photoconductive drum is described in any one of claims 1 to 9. An image forming apparatus using a hysteresis motor.