JPH02138545A - Rotation mechanism - Google Patents

Abstract

PURPOSE:To eliminate poor quality due to non-uniformity in the feed of a driving system by constituting a device that magnetic force acts between the first rotating body and plural numbers of the second bodies. CONSTITUTION:A paper feed roller 10 is monolithically connected co-axially with a sun roller (No.1 rotating body) 1, and the first through fourth photo-sensitive bodies (111 through 114) are monolithically connected co-axially with friction rollers (No.2 rotating bodies) 21 through 24 respectively. The rollers 21 through 24 are rotatably supported by a slot provided for a side plate in such a way as to be freely moved to some extent to the center direction of the roller 1 so that an elastic ring 3 is constituted to be rotated. The rollers 21 through 24 are composed of permanent magnet so that attracting force is effected to the roller 1 and the elastic ring 3. And the inner diameter of the elastic ring 3 is made to be more or less smaller than the inscribing inner diameter of the roller 21 through 24 so that pre-load is applied in advance. This constitution permits the stability of friction force to be increased, thereby enabling friction force to be uniform with rotating accuracy enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a drum rotation mechanism for a copying machine, particularly a color copying machine that requires synchronization, and can also be used as a speed reduction mechanism.

BACKGROUND ART Recently, the required level of image quality has become higher, and it is desired to improve the feeding accuracy of photoreceptor drive mechanisms such as copying machines. Generally, a waste moving part that constitutes a recording/reading part of a copying machine, scanner, printer, etc. uses a motor, and the speed is reduced to a required rotational speed by a mechanical element such as a gear.

FIG. 6 is a diagram showing an example of a rotation mechanism of a color printer, in which 21 is a motor, 22 is a pinion gear, 23 is an intermediate gear, 24 is a paper feed roller, 25 is a first photoreceptor, 2
6 is a second photoconductor, 27 is a third photoconductor, and as shown in FIG.
27, each of which is accompanied by a developing roller, a toner replenishing unit, etc., although not shown. The paper feed roller 24 is rotated by the driving force of the motor 21 that is decelerated by the intermediate gear 23, and the first to third photoreceptors 25 to 27 are also driven by the paper feed roller 24. At this time, a DC motor is often used as the motor 21, and the single paper feed roller 24 is decelerated in advance by a gear box.
The first to third photoconductors (in the case of color, the toner is yellow, magenta, cyan, or a combination of these and black) 25 to 27 are required to have stable rotation and high precision without unevenness. As for the drive, with the above-mentioned configuration, uneven rotation occurs especially due to the meshing of the gear teeth. Particularly when cost is required, the gear accuracy is limited to about 4th to 6th grade, and the accuracy cannot be increased unnecessarily.

The same applies to other mechanical elements, such as a dimming belt. In order to improve image quality, it is necessary to eliminate the rotational unevenness that occurs when the teeth mesh as described above.

Furthermore, torque transmission using a friction roller method by rolling depends on frictional force. Therefore, if this frictional force is small, the torque that can be transmitted is small, causing slippage, which not only impairs performance, but also increases wear and significantly reduces the torque transmission ability. In order to prevent this, we have tried to improve the material of the contact part, but since there are limits to this, we have increased the pressing force of the elastic ring. However, if this pressing force is increased, the following various problems occur.

■The amount of strain in the elastic ring increases, making it more likely to become permanently deformed.

■To increase the pressing force, generate electromagnetic force (for example.

(e.g. plunger) must be made larger,
This is disadvantageous in terms of power consumption, heat generation, etc.

■In the case of an elastic ring, when the amount of strain increases, the contact area with the roller becomes smaller and strong contact pressure is generated locally, causing deformation and wear.

l-1ka The present invention was made in view of the above-mentioned circumstances, and
This was done with the aim of eliminating poor image quality in copying machines, etc., which is called jitter or banding, which is caused in particular by uneven feeding in the drive system.

(2) In order to achieve the above object, the present invention includes a first rotating body, a plurality of second rotating bodies arranged around the first rotating body, and a plurality of second rotating bodies. A rotating mechanism that has a third rotating body inscribed in a rotating body and transmits drive by applying a pressing force to each rotating body, wherein the first rotating body and the plurality of second rotating bodies
The feature is that a magnetic force is applied between the rotor and the rotating body. Hereinafter, the present invention will be explained based on examples.

FIG. 1 is a block diagram of main parts for explaining the operating principle of the present invention, and FIG. 2 is a perspective view. In the figure, 1 is a sun roller (first
(rotating body), 2□ to 24 are friction rollers (second rotating body)
, 3 is an elastic ring (third rotating body), as shown in the figure,
A plurality of friction rollers 21 to 24 are arranged around the sun roller 1, and are capable of rotation and revolution by rolling. An elastic ring 3 is inscribed on the outer periphery of each friction roller so as to apply a pressing force to each friction roller. In such a configuration, for example, when the sun roller 1 is rotated without rotating the first elastic ring 3, the friction rollers 21 to 24 revolve while rotating. A large reduction ratio can be obtained by extracting the rotation of this revolution.

In the present invention, for example, the sun roller 11 elastic ring 3 is made of a ferromagnetic material, and the friction rollers 21 to 24 are made of permanent magnets.By doing so, the adhesion of each roller is increased and Highly accurate rotation transmission can be obtained.

FIGS. 3 and 4 are diagrams showing an embodiment in which the pressing force of the elastic ring 3 and magnetic force are used together.

21. Each of the friction rollers 2□ and 4 is made of a permanent magnet made of rare earth cobalt or the like. Sun roller 1 and elastic ring 3
is made of ferromagnetic material. The friction roller 4 is regulated by an elongated hole 61 of an arm 6 which is rotatably supported by the shaft of the sun roller 1, and rotates around the sun roller 1 by the rotation of the arm 6. The arm 6 is given a clockwise rotational habit by a spring 8 whose one end is secured to a side plate (not shown). When in use, arm 6
The tip of the arm 6 is pulled out by a link 7 of a plunger 5 fixed to a side plate, and the arm 6 rotates counterclockwise and is positioned by hitting a stopper 9. When not in use, the plunger 5 is de-energized and the arm 6 is rotated clockwise by the spring 8, as shown in FIG.

Elastic ring 3 and friction roller 2. , 22.4, a clearance g occurs, and the pressing force by the elastic ring 3 disappears, leaving only the attraction force due to the magnetic force of the friction roller.

FIG. 5 shows an embodiment in which the present invention is applied to the paper feed and photoreceptor drive of a copying machine. roller 2
The first to fourth photoreceptors (1 to 24) are coaxially arranged, respectively.
1□, 11. ,...) are physically connected. Furthermore, the friction rollers 21 to 24 are supported with a certain degree of freedom in the direction of the center of the sun roller through elongated holes similar to 6□ provided on the side plates (not shown), and are prevented from rotating as shown in FIG. Instead, the elastic ring 3 rotates. Friction rollers 21-2
4 is composed of a rare earth permanent magnet (or may be a plastic magnet, a rubber magnet, etc.), and exerts an attractive force on the sun roller 1 and the elastic ring 3. Further, the inner diameter of the elastic ring 3 is slightly smaller than the inner diameter of the friction rollers 2□-24.

A preload is applied in advance. Incidentally, if there is a concern that the contact point may be deformed due to preload, this can be prevented by incorporating the mechanism shown in FIGS. 3 and 4. Further, any of the sun roller, friction roller, and elastic ring may be a permanent magnet, or may be an electromagnet if necessary.

Effect-11 As is clear from the above description, according to the present invention, the stability of the frictional force is increased by using both the attraction force of the permanent magnet and the pressing force of the elastic ring.

Uniform frictional force can be obtained, improving rotation transmission accuracy. In particular, when high torque transmission is required, applying strain only to the elastic ring may cause the side effects described in the prior art section, but by applying the present invention, high torque transmission can be performed with high accuracy and long life. can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of main parts for explaining the operating principle of the present invention, FIG. 2 is a perspective view, and FIGS. 3 and 4 are diagrams for explaining the operation of the pressing force of the elastic ring. , FIG. 5 is a diagram showing an example of the case where the present invention is applied to paper feeding and driving of a photoreceptor in a copying machine, and FIG. 6 is a diagram for explaining an example of a conventional rotation mechanism. 1... Sun roller, 21-2. ...Friction roller, 3
... Elastic ring, 4... Movable friction roller, 5...
plunger, 6... arm, 7... link, 8...
...Spring, 9...Stopper Fig. 1 Section Fig. Fig. Q Fig.

Claims (1)

[Claims] 1. It has a first rotating body, a plurality of second rotating bodies arranged around the first rotating body, and a third rotating body inscribed in the plurality of second rotating bodies. , a rotation mechanism that transmits drive by applying a pressing force to each rotating body, characterized in that a magnetic force is applied between the first rotating body and the plurality of second rotating bodies. mechanism.