JPH0510322A - Highly durable rotary member - Google Patents

Abstract

PURPOSE:To provide a highly durable rotary member which compensates for use of the material having the less abrasion resistance and strength. CONSTITUTION:The journal parts A, B, and C of a rotary member consisting of a development sleeve 7, paddle wheel 6, and an agitator 5 are metallization- covered uniformly by the abrasion-resistive material, and each covered layer consisting of the abrasion-resistive material is formed on the outer peripheral surfaces of the journal pars A, B, and C.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotating member such as a shaft which is rotated by receiving a load.

[0002]

2. Description of the Related Art Innumerable rotating members are used in various mechanical devices. For example, when the rotating member is a single shaft, the shaft is rotatably supported by a machine side plate or the like via a bearing in some form or another. If the bearing is a roller bearing, the inner ring of the inner ring,
In the case of a slide bearing, the shaft portion is fitted into the inner peripheral portion of this bearing, and such a shaft portion is called a journal portion (shaft neck portion). Further, a gear or sprocket for driving is attached to such a shaft portion, and the shaft portion to which such a thing is attached is also
Broadly understood, hereinafter referred to as the journal section.

Naturally, such a journal portion receives a predetermined radial load or thrust load, but if this journal portion is used for a long period of time, the journal portion will be worn out, and "backlash" will occur between bearings and the like. The rotation accuracy of the rotating member deteriorates. That is, when the journal part has a shaft supporting structure in which the journal part is in contact with the slide bearing, the journal part slides relative to the bearing, so that the journal part is worn by the frictional force between them. This causes "backlash" between the bearings. Further, even when a gear or the like is fitted and fixed to the journal portion, there is no relative sliding between the two, but due to the radial load described above, the journal portion becomes worn away, and the arrow tension, the gear There will be "play" between and.

Recently, in this type of mechanical device, in order to further reduce the weight, a light metal such as aluminum or a synthetic resin is also used for each component. However, such materials are apt to suffer from insufficient strength and are vulnerable to wear. Therefore, at present, hesitant to use such materials for rotating members. It is about to be done.

Conventionally, such rotating members made of steel such as stainless steel have been widely used, and their strength and wear have been relatively well coped with. If such a machine is used, the machine weight will inevitably increase, and much time will be required for cutting and the like.

Therefore, it is possible to reduce the weight of the apparatus by using a rotating member made of a light metal such as aluminum or a synthetic resin, but if such a member is used, the strength is inevitably increased. It is easy to run short, and
Since it is vulnerable to wear, the use of such a material has not been actively promoted in the past.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a highly durable rotating member which can complement the wear resistance and strength of a material which is inferior.

[0008]

In order to achieve the above-mentioned object, the present invention achieves the above-mentioned object by at least a part of the journal portion of a rotary member being spray-coated with a wear-resistant substance evenly. The present invention proposes a highly durable rotating member formed by forming a coating layer of the wear resistant material.

It is effective that the rotating member is made of light metal.

Further, it is effective that the rotary member is a molded product made of synthetic resin.

Further, it is effective that the coating layer is an oil-impregnated coating layer for lubrication.

Further, it is effective that the rotating member is a rotating member of the image forming apparatus.

[0013]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view of essential parts showing a drive unit of a developing device including a highly durable rotating member according to an embodiment of the present invention. Before describing this, the overall configuration of the image forming apparatus having the developing device will be clarified.

FIG. 2 is a schematic view of an electrophotographic image forming apparatus. Reference numeral 1 denotes a drum-shaped photoconductor, and the photoconductor 1 is rotationally driven in the arrow direction shown in the figure. During this rotation, the surface of the photoconductor 1 is uniformly charged by the charging charger 2, and the surface thereof is irradiated with the optical image indicated by the arrow P, so that a predetermined electrostatic latent image is formed on the surface of the photoconductor. It is formed.

The developing device 3 includes an agitator 5 for stirring the developer 4 in the device, a paddle wheel 6 for pumping the stirred developer, a developing sleeve 7 for receiving the developer pumped by the paddle wheel, and the like. Have Inside the developing sleeve 7, there is a magnet roll 8
Is provided, and the developer supplied onto the developing sleeve 7 is conveyed in the direction of the arrow by rotationally driving both or one of them, and the developer is transferred to and from the photoconductor 1 by the developer. The upper electrostatic latent image is visualized as a toner image.

On the other hand, the transfer paper 11 from the registration roller 9
Is sent to the photoconductor 1 at a timing, and the toner image on the photoconductor is transferred to the transfer paper 11 by the action of the transfer charger 12. Thereafter, the transferred toner image is fixed while the transfer paper passes through the fixing roller 13.

Returning to FIG. 1, the developing sleeve 7 is substantially integrated with the shaft cylinder member 14, and the shaft cylinder member 14 is the bearing 1.
It is rotatably supported by the side plate 16 of the developing device via 5. The shaft cylinder member 14 is rotatably supported by the shaft 8A of the magnet roll 8 via a bearing 17 and a slide bearing 18. The plain bearing 18 is substantially integrated with the shaft cylinder member 14.

The paddle wheel 6 is fixed to the paddle wheel shaft 6A, and the shaft 6A is rotatably supported by the side plate 16 via a bearing 19. Further, the agitator 5 is fixedly attached to the shaft 21, and the shaft 21 is attached to the side plate 1.
6 is rotatably supported by a slide bearing 22 fixedly mounted on the shaft 6.

The shaft cylinder member 14, the side plate shaft 23, the paddle wheel shaft 6A, and the agitator shaft 21 include gears 24,
The idle gear 25, the gear 26, and the gear 27 are attached to each other, and these mesh with each other and rotate,
Developing sleeve 7, paddle wheel 6, and agitator 5
And are rotationally driven in the directions of the arrows in FIG.
In this example, the magnet roll 8 is held in a non-rotating state. In the figure, reference numeral 2
Reference numerals 8, 29, and 30 denote seal members for preventing the development of so-called bearing lock and the like by preventing the developer and other foreign substances from entering the bearing portion. For example, a pad material such as a so-called G seal or felt seal is used.

Here, in this embodiment, the developing sleeve 7
The paddle wheel 6, the agitator 5, etc., are rotating members. Now, paying attention to a rotary member such as the agitator 5, the shaft 21 rotates while sliding at a portion in contact with the seal member 30 and the slide bearing 22. Although such a shaft portion receives a radial load, such a portion is called a journal portion (shaft neck portion) as described above. The shaft portion into which the gear 27 fits is also called a journal portion because it receives such a load. That is, in this example, the shaft portion indicated by A of the shaft 21 is the "journal portion".

The radial load, the frictional force on the sliding surface (the frictional force between the sliding bearing 22 and the shaft 21) and the like are the loads applied to the journal portion A.
As the load increases, the strength of the journal portion needs to be increased, and it is necessary to prevent the wear of the portion from being accelerated.

In order to meet such a demand, conventionally, the shaft, which is the rotating member, is made of rust-proof steel, but using such a material leads to an increase in weight. Moreover, the cutting process is required, which increases the processing cost and increases the device cost. Recently, stainless steel has been widely used from the viewpoint of rust prevention and corrosion prevention, but if such a steel is also used, the cost tends to be higher.

For this reason, such rotating members have been manufactured by aluminum die casting, synthetic resin molding or the like. With this method, the weight is reduced and the manufacturing is facilitated. Can be expected,
Inevitably, it is easy to fall into insufficient strength and weak in wear.

The present invention is to increase the strength and durability of a rotating member made of a material having characteristics such as light weight and good workability.

That is, for example, the journal portion (A portion) of the shaft 21 is uniformly spray-coated with a wear-resistant substance, so that a coating layer of the wear-resistant substance is formed on the outer peripheral portion of the journal portion A. is there. There are various types of coating materials (antiwear materials) that form the basis of such coating layers,
For example, those shown in Table 1 below can be listed. In addition to those listed in this example, ceramics, stainless steel, stellite, or other various metals can be used.

[0026]

[Table 1]

The powder of such an abrasion resistant material is made to collide with the journal portion at a high speed by the plasma method or the arc method. At this time, the particles are deformed into a flat state, entangled with the uneven surface of the base (journal portion), and a coating layer made of a wear-resistant substance is formed. For example,
By spraying gray alumina, the film thickness can be reduced from about several μm to several thousand μm, and the film thickness is not limited at all.

As the material (base), in addition to metal,
There are a wide variety of materials such as glass and plastic, and paper and the like can be coated with such an abrasion resistant material. The integration of such an abrasion resistant material into the material is extremely good, and it is now necessary to firmly coat the surface of the material with such an abrasion resistant material by electroplating, chemical plating or other methods. However, it is getting harder. It should be noted that by coating with such a wear-resistant substance, it also has excellent corrosion resistance and the like.

When hard alumite (HAl) or the like is used for the rotating member in addition to steel, the strength can be expected to be increased, but the surface roughness is deteriorated and the cost is increased. Also, plating is not very versatile. In this example, it is not necessary to use such hard alumite as the rotating member, and a light metal, for example, a light alloy such as normal aluminum can be used.

The material surface does not need to be finished so smoothly, but rather the surface should be rough,
The binding force with the coating material becomes stronger. If the surface of the journal is required to be smooth, the surface may be ground and finished after thermal spraying.

In FIG. 1, the portion B of the magnet roll shaft 8a is a portion in contact with the sliding bearing 18, and in this portion, the sliding bearing 18 slips around the shaft 8A, so that the shaft 8A is rotated. When using aluminum,
The amount of wear increases. Then, the plain bearing 18 and the shaft 8
The degree of mutual engagement with A becomes too loose, resulting in not only drive loss but also deterioration in rotation accuracy of the developing sleeve.
The gap between the photosensitive drum 1 and the developing sleeve 7 may be misaligned. Although this adversely affects the image, it is possible to prevent such abrasion from being promoted by forming the above-described coating layer on the journal portion B.

By extending such a coating layer to the portion of the bearing 17, it is possible to increase the strength on the bearing side and improve the wear resistance. Such strength can also be increased by coating with a wear resistant material.

Further, with respect to the shaft cylinder member 14, the gear 24
As shown in FIG. 3, the coating portion 3 of the wear-resistant material is used for the journal portion with which the bearing 15, the seal member 28 and the like are in contact.
1 is formed. The shaft cylinder member 14 does not slide relative to the bearing 15 and the gear 24, but a considerably large radial load is applied to the shaft cylinder member 14. Due to such a load, the shaft cylinder member wears away so as to reduce its diameter over time, but the coating layer 31 increases its strength so as not to promote such "wearing". Can be done. Regarding the seal member 28 as well, although the radial load at this portion is not so large, the seal member 28 slides relative to the shaft cylinder member 14 and the arrow tension and the shaft cylinder member wear. If such wear occurs, the torque will increase. Further, the developer or the like may enter the bearing, which may hinder the rotation of the shaft or generate noise. By forming a coating layer also on such a portion, it is possible to prevent the abrasion thereof from being promoted and prevent the sealing function from being impaired.

As the bearings 15, 17, 19 and the like, rolling bearings such as ball bearings are used, and as the sliding bearings 18 and 22, resin sliding bearings such as oil-impregnated polyacetal and oil-impregnated bearings such as dry bearings. Although a bearing is used, from the viewpoint of cost, efforts have been made to shift to the latter slide bearing, and when such a slide bearing is used, the shaft that is the rotating member slips relative to it, The journal portion of the shaft is easily worn. The coating of anti-wear material is particularly effective for such relative sliding parts.

In the journal portion coated with the wear-resistant material, the oil-impregnated portion for the sprayed portion does not require the oil-impregnated treatment for lubrication on the sliding bearing side. That is,
The degree of freedom in selecting the bearing material is high, and it is advantageous in terms of cost if an ordinary bearing is used instead of an oil-impregnated bearing.
In some cases, if the coating layer is oil-impregnated, the shaft portion of the rotating member can be directly supported in the hole of the side plate or the like without using a bearing.

Regardless of whether the side plate is made of synthetic resin or metal, if only the hole through which the shaft passes is provided in the side plate, the lubricating oil will exude from the coating layer and the wear of the side plate hole will not be accelerated. Can be done.

It is very effective to have such a coating layer structure for the journal portion such as the light load portion and the high rotation speed portion, and it is possible to significantly reduce the number of bearings and, depending on the case, It is also possible to eliminate all the dedicated bearings.

When the journal portion of the rotating member is worn and interferes with its rotating function, normally,
Despite the fact that the other parts of the rotating member can be used without problems, they have been discarded. In recent years, as environmental problems such as an increase in garbage waste have been addressed, it is desired to reduce such waste as much as possible. When the coating layer applied to the journal part of the rotating member is worn out, or
When the worn-out material is once collected and discarded, the rotating member can be reused many times by forming the coating layer in the same manner again.
It can play a part in solving environmental problems.

Incidentally, as the material of the rotating member, a light metal such as aluminum may be used, but in addition to this, it may be a molded product made of synthetic resin. Also in the case of this material, wear is likely to occur and the strength is insufficient.

Regarding the paddle wheel 6 shown in FIG.
Conventionally, the paddle wheel body is integrally formed of ABS resin, hard vinyl chloride resin, or the like, and the metal shaft 6A is press-fitted into the paddle wheel body.
By similarly molding the shaft 6A with the paddle wheel main body 6 using a synthetic resin and forming a sprayed coating layer of a wear resistant material on the journal portion C of the shaft 6A, the wear resistance of the journal portion is similarly improved. It can be improved and its strength can also be increased. Then, the processing cost of the paddle wheel 6 can be greatly reduced. Similarly for the agitator 5 or the developing sleeve 7,
The shaft 21 or the shaft cylinder member 14 may be formed into a synthetic resin product, and in this case, a sprayed coating layer of a wear resistant material is formed on each journal portion.

As shown in FIG. 2, the photosensitive drum 1
The shaft 1A and the rotating members such as the registration roller 9 and the fixing roller 13 are made of a material such that they are easy to mold and have a light weight but are easily worn by using the above-mentioned coating layer structure of the journal portion. Even if a material having a weak point is used, its wear resistance can be improved. In addition to such an electrophotographic image forming apparatus, the present invention can be applied to rotary members used in office automation equipment such as facsimiles, printers, and word processors. Furthermore, the same function can be achieved by forming a sprayed coating layer of a wear resistant material on the sliding portion of a member that moves linearly instead of rotating.

In the above-described embodiment, the coating layer is formed on the entire journal portion of the rotary member, but the coating layer may be formed only on a part of the journal portion in consideration of the load acting on the journal portion. it can.

[0043]

According to the highly durable rotating member of the first aspect, even if a material having poor wear resistance and strength is used, the strength and wear resistance can be enhanced. The low-cost, easy-to-machine rotating member, which is an advantage of the material, can be used for various equipment.
It can help reduce the cost of the device. At the same time, by using such a rotating member, it is possible to prevent the rotational accuracy of the rotating member from deteriorating with time.

According to the highly durable rotating member of the second aspect, it is possible to reduce the weight of the device to which the rotating member is attached.

According to the highly durable rotating member of the third aspect, it is possible to make the rotating member into a complicated shape, the workability thereof is improved, and the equipment for attaching such rotating member is lightened. be able to.

According to the highly durable rotating member of the fourth aspect, no special oil-impregnated bearing is required, and the bearing cost of the equipment can be reduced.

According to the high durability rotating member of the fifth aspect, it is possible to reduce the weight of the image forming apparatus, and to improve the rotational accuracy of various rotating members provided in the image forming apparatus over time. It can be prevented from lowering.

[Brief description of drawings]

FIG. 1 is a sectional view of essential parts of a developing device including a highly durable rotating member according to an embodiment of the present invention.

FIG. 2 is a schematic view of an entire image forming apparatus including a developing device and the like.

FIG. 3 is a cross-sectional view of a main portion of a shaft portion of a developing sleeve.

[Explanation of symbols]

5 Agitator as rotating member 6 Paddle wheel as a rotating member 7 Developing sleeve as rotating member 31 coating layer

Claims (5)

[Claims] 1. A highly durable rotation in which at least a part of a journal portion of a rotating member is uniformly spray-coated with a wear-resistant substance to form a coating layer of the wear-resistant substance on the outer peripheral portion of the journal part. Element. 2. The highly durable rotating member according to claim 1, wherein the rotating member is made of light metal. 3. The highly durable rotating member according to claim 1, wherein the rotating member is a molded product made of synthetic resin. 4. The highly durable rotating member according to claim 1, wherein the coating layer is an oil-impregnated coating layer for lubrication. 5. The highly durable rotating member according to claim 1, 2, 3 or 4, wherein the rotating member is a rotating member of an image forming apparatus.