JPH0450876A - Powder container sealing device - Google Patents

Abstract

PURPOSE:To obtain a developer container sealing device so that a leaked developer does not reach a bearing part by collecting the leaked developer with a sealing member. CONSTITUTION:A rotary shaft 4 passing through a container 3 housing powder, and protruding to the outside is provided, and further, the sealing member 14 blocking the infiltration of the powder to the bearing parts 32 and 33 supporting the rotary shaft 4, is provided. And, powder stagnating parts 35 and 36 collecting the powder leaked from the sealing member 14 is formed. The developer used for a long time and slipping out is collected by the developer stagnating parts 35 and 36 before it reaches the bearing parts 32 and 33, and stored when it is stagnated in some degree. thus, even if the developer slips out the sealing member 14, reaching the bearing parts 32 and 33 is prevented.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a powder container seal for electrophotographic or electrostatic copying machines, printers, etc. that use powdered developer for image formation. This relates to a stop device.

[Prior Art] Generally, dry electrophotographic copying machines and electrostatic copying machines and printers handle powdered developer or waste toner inside the apparatus. Typical examples include a developing device, a developer replenishing device, a cleaning device, etc., and these devices store developer and waste toner inside a container. These devices most often include means for internally agitating or transporting the developer. The mechanisms include, for example, a rotating screw, a rotating shaft with a stirring plate, and
The developer is conveyed and stirred, and the waste toner is conveyed by means of a thin plate formed into a coil shape with a rotary shaft provided at one end and rotated. In most of these devices, a rotating shaft passing through the inside and outside of the container is a component of the mechanism. Therefore, at least one end of the rotating shaft is supported by a part of the container via a bearing such as a ball bearing or a sliding bearing, and is placed inside the container from the bearing so that the developer or waste toner does not come into contact with the bearing. The structure has a sealing member such as an oil seal at the position.

FIGS. 1i and 113 show a developing device as an example of the structure described above. This developing device 1 is of a so-called two-component developing type, and receives toner from a toner replenishing device (not shown) at a toner replenishing port 2. Two screws, a screw 4 and another screw (not shown) parallel to the screw 4, are provided inside the developing container 3 of the developing device 1. In FIG. 11, which is a plane longitudinal cross-sectional view including the developing sleeve 5 and screw 4 of this developing device 1, a latent image carrier (not shown) and the developing sleeve 5 are shown at both ends of the developing sleeve 5. An abutment roller 6 is provided to accurately maintain the gap. Developing sleep 5 is connected to gear 7 from the outside.
It rotates by receiving driving force through it. Then, the rotational force of the developing sleeve 5 is transmitted from the developing sleeve 5 to the screw 4 through a gear train consisting of gears 8, 9, 10, etc., causing the screw 4 to rotate.

The screw 4 forms a circulation path together with the other screws L and other screws provided in parallel thereto, and a partition plate 11 provided between these screws, so that the developer is conveyed while being stirred.

The screw 4 is rotatably supported at both ends by a slide bearing 12 and a slide bearing 13, respectively. The plain bearing 13 has an outer diameter larger than the screw diameter so that the screw can pass through the housing sink hole during assembly. Rubber oil seals 14, 14 are fitted into the sliding bearings 12 and 13 to prevent developer from entering the sliding contact portions 12A and 13A of the bearings.

Thus, during the developing operation of the developing device 1, at the same time as the developing sleeve 5 rotates, the screw 4 also rotates to agitate and circulate the developer, thereby supplying the developer with a uniform concentration to the developing sleeve 5. There is.

However, the conventional developing device described above has the following problems.

In general, in the case of a one-component type developer, metal magnetic particles are embedded in resin particles, and in the case of a two-component type developer, color-forming resin particles and metal magnetic particles of approximately several μ to several fiL1 are used. (typically iron powder), and it is extremely difficult to completely seal the developer made of these components with a sealing member such as an oil seal. In the device shown in FIG. 11 described above, when the metal component in the developer gets between the lip of the rubber oil seal 11 and the rotating shaft, it not only accelerates the wear of the lip, but also the resin component. It melts at a microscopic level due to the frictional heat between the lip and the rotating shaft, deteriorating the oil seal and causing it to slip through.

Also, with the aim of improving image quality, there has recently been an active effort to reduce the particle size of toner, and is it possible that small particle size toner with a diameter of 2 to 3 connections will also be used?In that case, the surface of the rotating shaft Because the roughness and particle size are close to each other, small amounts of the material may always slip through, which accelerates the deterioration of the sealing member and increases the load on the bearing.

Due to these factors, if the developer starts leaking into the bearing, if the bearing is a sagging bearing like the conventional one, it will cause abnormal wear on the sliding contact area and increase the load. In some cases, developer may enter the ball bearing, increasing the load and eventually causing it to lock.

In order to prevent developer leakage due to deterioration of seal members such as oil seals, seal members have traditionally been replaced periodically. That is, the method is to replace the seal member before it wears out and developer leaks out. This way, leakage can certainly be prevented, but the big problem here is that the intervals between periodic replacement of the sealing member are short.

When a sealing member such as an oil seal is used in a developing device, its lifespan varies greatly depending on a few factors, and it is difficult to estimate it. In the case of conventional models, factors that affect the life include, for example, flaws or roughness on the surface of the shaft, variations in the outer and inner diameters of the bearing, variations in the hole diameter on the developer container side that fits into the bearing, and oil seals. Due to various factors such as the inclination of the oil seal when it was installed, the inventor's experiments showed that the life of the oil seal varied approximately five times over the average. In the conventional case, leakage of developer would immediately lead to the locking of the bearing, and to ensure that developer never leaked, the timing for replacing the seal member was set according to the shortest lifespan. Therefore, a service person had to replace the seal member at relatively short intervals, increasing the service cost.

The present invention solves this problem by sealing a developer container in which, even if developer leaks, the seal member collects the leaked developer and prevents the leaked developer from reaching the bearing part. Entered for the purpose of providing equipment.

[Means for Solving the Problems] According to the present invention, the above-mentioned object includes: a rotating shaft having at least one end penetrating the container and protruding to the outside in a container for storing powder; In a bearing that supports the shaft, which is equipped with a seal member located inward in the axial direction to prevent powder from entering the bearing, leakage from the seal member occurs between the seal member and the bearing. This is achieved by forming a powder reservoir to collect the collected powder.

[Operation] In the present invention as described above, the powder, such as the developer, is sealed by the sealing member. However, after long-term use, it is inevitable that a small amount of the developer will slip through the sealing member. In the present invention, the developer that has slipped through is collected in the developer reservoir before reaching the bearing, and is collected when it has accumulated to a certain extent or during periodic inspection.

In this way, even if the developer slips through the seal member, it does not reach the bearing portion.

[Example] Hereinafter, the present invention will be described in detail based on FIGS. 1 to 9 of the accompanying drawings.

An example in which the present invention is applied to a full-color electrophotographic copying machine will be described below, but the present invention is not limited thereto, and can also be applied to developing devices such as general black-and-white copying machines and printers. Needless to say.

In addition, it can be widely applied not only to developing devices, but also to powder sealing mechanisms of devices that handle powder, such as the developer stirring section and conveyance section of hoppers, and the waste toner conveyance device of latent image carrier cleaning devices. Of course.

First, the structure of a full-color electrophotographic copying machine as an example of a device that can be used with the apparatus of this embodiment will be described with reference to FIG.

In this embodiment, the full-color electrophotographic copying machine has an optical system 50 disposed above, and the reflected light image obtained by scanning the original image on the platen 51 is transmitted to a CCD equipped with a BGR color separation filter.
52. The CCD 52 converts the original image into electrical signals for each color, which are sent to a microprocessor unit MPIJ (not shown).

Based on this signal, the MPLI oscillates a laser beam from a laser unit 53 to form a latent image on a photosensitive tram 54, which is a latent image carrier.

Surrounding the photosensitive tram 54 are a primary charger 55, a developing device 1 loaded with four developing units (IM, IC, IY, 1B) and movable in the left and right direction, and a transfer device 58. and a cleaning device 59.

With the above configuration, the photosensitive drum 54 is used for each electrophotographic process such as charging, exposure, development, transfer, and cleaning, as well as the colors separated by the CCD 52, the primary charger 55, and the optical system 5.
0, developing device l, transfer device 58, cleaning device 59
A full-color image is created using the method. The transfer material P is fed from the supply device 60 to the transfer device, and the image on the photosensitive drum is transferred. Transfer material P separated from the transfer device
is conveyed to the fixing device 61, and after being fixed, is discharged outside the machine. Such an image forming process and the structure and operation of each member are well known to those skilled in the art, so further detailed explanation will be omitted.

Next, the developing device 1 will be explained in detail with reference to FIGS. 1, 3, and 4. In addition, in the figure, Figure 1O and Figure 1T
Components common to the conventional device shown in the figure are given the same reference numerals.

The developing unit is composed of parts common to each color, and only the developer supplied inside is different depending on the color. In this embodiment, the developer is assumed to be a two-component developer in which a toner and a carrier, which is a magnetic powder, are mixed at a constant ratio.

The developing device 1 rotatably supports a developing sleeve 5, which is a developer carrier that supports and conveys the developer contained in the developing container 3 toward the photosensitive drum. The developing sleeve 5 is rotationally driven by a drive gear 7 connected to a developing unit drive system (not shown). A magnet roller 21 (FIG. 4) is arranged inside the developing sleeve 5, and is fixedly attached to the developing container 3 by a magnetic pole determining plate.

Abutting rollers 6 are provided near both ends of the developing sleeve 5 to maintain the distance between the photosensitive drum and the developing sleeve 5 at a predetermined value.

The conveying pipe portion protruding from the developer container 3 is provided with a toner replenishment port, as in the conventional device shown in FIG. or be replenished.

In order to transport the replenished toner and stir the toner and carrier, a transport screw 4 and a transport screw 4A are arranged in parallel in the developer container 3, as shown in FIG. 4.

As seen in FIG. 3, the drive system of the developing unit consists of a sleeve surface 6 coaxial with the driving gear 7 of the developing sleeve 5, which is attached to the conveying screws 4 and 4A by an idler gear 9 and an IOA, respectively. Gear 10. It meshes with the IOA to transmit rotation, and therefore, the developing screen 5 is configured to always rotate in the same direction as the conveying screw 4 and the conveying screw 4A.

Next, referring to FIG. 4, the Macnet roller 21 disposed inside the developing sleeve 5 is 5ltS2+N1+N2+
It has five N3 magnetic poles. During the developing operation, the developing sleeve 5 rotates in the direction of arrow C, and conveys the developer drawn up by magnetic force in the order of N2→S2→N, →S1→N3.

At this time, the amount of developer conveyed is regulated by the doctor blade 22. S1 is the developing main pole, and here the developer in a state where the spikes are standing up, so-called standing spikes, or the photosensitive drum 1
Develop the electrostatic latent image. The developer that has reached N U falls from the sleeve surface into the developer container due to the repulsive magnetic field formed between N3 and N2 of the same polarity.

Next, the characteristic parts of the present invention will be explained with reference to FIG.

In FIG. 1, the screw 4 is rotatably supported by a slide bearing 32 and a slide bearing 33. The sliding bearings 32 and 33 have the following as in the conventional example shown in FIG.
Oil seals 14 and 14 are fitted respectively,
This prevents developer from entering the sliding contact portions 32A and 33A.

Now, the bearing 12 on the left side in FIG. 1 is different from the bearing 13 in the conventional device shown in FIG. 11 in that a hole 34 is provided therein. Further, the developer container 3 is provided with a developer reservoir 35 communicating with the hole 34 .

Inside the developer container 3, as shown in FIG. 5, another screw 4A is provided in parallel adjacent to the screw 4, and a bearing 32, a hole 34, and a developer reservoir are also installed in the developer container 3. The section 35 is provided in the same manner as in the case of the screw 4.

The bearing 33 on the right side in FIG.
A developer reservoir 36 is provided therein. Similarly to FIG. 5, FIG. 6 shows a cross-sectional view of the developer reservoir 36 when viewed from the direction of axis A.

In this embodiment with such a configuration, when the developing device 1 continues to perform the developing operation, if the oil seal deteriorates and developer starts leaking from the bearing 32 before the periodic oil seal 14 is replaced, The leaked developer falls into the developer reservoir 35 via the hole 34 before reaching the sliding contact portion 32A. In addition, conventional equipment♂
In a two-component developing device, the toner contains particles with a particle diameter of 2 to 3 gm, which is close to the roughness of the surface of the screw shaft, so even before the oil seal deteriorates, only a small amount of particles are mixed in. In this embodiment, in such a case, the leaked toner is also guided to the developer reservoir 35.
It does not reach the sliding contact part 32A. As can be seen from FIGS. 1 and 5, a developer reservoir 35 is provided in the developer container 3, which has sufficient space, and leaked developer is guided there. Compared to the case shown in FIG. 11, even if the developer were to leak from the oil seal, it would be difficult to reach the sliding contact area of the bearing, and the time for any damage to occur could be much longer.

The same phenomenon occurs in the bearing 33 as in the bearing 32, and in this case, the developer reservoir 36 provided in the bearing itself
The leaked developer will be guided away.

In this way, even if there is early deterioration of the oil seal or unavoidable leakage of a small amount of toner, the time it takes for the developer reservoir to become completely full can be avoided from being affected by an increase in load or locking.

Next, another embodiment of the present invention will be described using FIGS. 7.8.9.

This embodiment can be applied to a developing device of a full-color electrophotographic copying machine similar to the previous embodiment, and only the parts different from the previous embodiment will be explained here.

FIG. 7 is a cross-sectional view of the developing device corresponding to FIG. 1, and the only difference here is that transparent acrylic windows 41 and 42 are provided. . The windows 41 and 42 may be made of any material as long as they are transparent.

FIG. 8 is a cross-sectional view corresponding to FIG. 5, and also shows the window 41.
The only difference from the case shown in FIG. 5 is that .

By providing the windows 41 and 42 in this way, the ninth
As shown in the figure, it is possible to visually check whether or not the developer is leaking beyond the oil seal 14 without removing the bearing 32 from the outside of the developing device.

In the absence of such a window, in order to find out whether the oil seal 14 has actually deteriorated and developer is leaking, in conventional devices, the bearing must be removed, and in order to do so, the developer in the developer container must be removed. It was very time-consuming and labor-intensive, as the agent had to be collected and emptied once, and the screw drive gear train also had to be removed. However, by providing the windows 41 and 42 as in this embodiment, leakage of developer can be easily checked by removing the developing device 1.

Therefore, by checking for developer leakage at intervals shorter than the regular oil seal replacement interval, even if the oil seal deteriorates earlier than its expected lifespan, developer leakage can be prevented the next time. You will find it when you check it, and in the meantime, serious troubles such as locking can be avoided due to developer accumulating in the developer reservoir.

In addition, as mentioned above, there is no actual harm even if the oil seal deteriorates before its expected lifespan, so there is no need to set the periodic oil seal replacement interval as short as in the conventional case, taking into account the safety factor. It is possible to reduce service costs and downtime.

[Effects of the Invention] As described above, according to the present invention, a powder reservoir portion is provided between the bearing of the rotating shaft of the powder stirring or conveying means and the seal member to collect the powder leaked from the seal member. Since this is provided, even if powder leaks from the sealing member, the powder will not reach the bearing, and problems such as seizure of the rotating shaft and abnormal wear of the bearing are less likely to occur.

Furthermore, by providing a window through which the powder reservoir can be viewed from the outside, it is now possible to easily check whether powder is leaking from the sealing member.

Therefore, if you check for leaks at shorter intervals than when all the powder leaks from the powder reservoir, even if the sealing member deteriorates earlier than the regular replacement time due to unforeseen causes, you can prevent problems before they occur. It became possible to detect and deal with it.

[Brief explanation of the drawing]

giI! Figure 1 is a longitudinal sectional view of an embodiment of the device of the present invention, Figure 2
The diagrams are a schematic diagram of a copying machine to which the device in Figure 1 can be applied, and Figure 3
The figure is a sectional view taken along line m-■ in Figure 1, and Figure 4 is a sectional view taken along line ff-I in Figure 1.
5 is a V-V sectional view in FIG. 1, FIG. 6 is a vx-vr sectional view in FIG. 1, FIG. 7 is a vertical sectional view of another example device, and FIG. ■-[Cross-sectional view of Fig. 7, Fig. 9 shows the
10 is a perspective view showing the external appearance of a conventional device, and FIG. 11 is a vertical sectional view of the device shown in FIG. 4・・・・・・・・・Rotating shaft (screw) 14
・・・・・・・・・・・・Seal member (oil seal)
32A, 33A...Bearing part (sliding contact part) 35.36...
...Powder reservoir section 41.42...Transparent window section

Claims (2)

[Claims] (1) A container containing powder has a rotating shaft with at least one end penetrating the container and projecting to the outside, and the powder is placed at an axially inner position of a bearing that supports the rotating shaft. In a device equipped with a seal member for preventing entry into the bearing part, a powder reservoir part is formed between the seal member and the bearing part to collect powder leaked from the seal member. A powder container sealing device featuring: (2) The powder container sealing device according to claim (1), wherein a part of the powder reservoir is provided with a transparent window that is visible from the outside of the container.