JPH04291282A - Sealing device suitable to use for image forming device - Google Patents

Abstract

PURPOSE:To prevent fine powder contained in a container, such as toner which is used for an image forming device, from leaking out of the peripheral part of a shaft extending through the wall part of the container, and also to prevent the powder from becoming lumpy and being incorporated into the original fine powder. CONSTITUTION:A partition member 5 is arranged in non-contact state with the shaft 6 in the further inner side of a sealing member 2 which is arranged inside a bearing 1 in a part where the shaft 6 extends through the container wall part 4, and a pressure force by fine powder is prevented from being applied to the sealing member 2 as much as possible, and also, the generated lump of the powder is prevented from returning to the part of the original fine powder.

Description

[Detailed description of the invention]

0001

[Purpose of the invention]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a powder sealing device suitable for use in image forming apparatuses such as electrostatic copying machines and printers.

0002

[Prior Art and Problems to be Solved] Currently, in the well-known image forming apparatuses described above, it is common to use fine toner particles as an image forming means, and therefore, the fine toner particles are stored and charged. In order to stir the toner and transport it to a predetermined location, it becomes necessary to insert a rotating shaft through the wall of the toner container in order to operate the internal stirring and transport means from outside the toner storage section. Therefore, it is essential to reliably prevent leakage of toner from the circumferential portion of the shaft. However, toner particles usually have a particle size of about 10 μm, and with the recent demand for improved image quality, the particle size tends to become even smaller, so it is not easy to create a seal that prevents toner from leaking out of the container.

"FIG. 3" is a side view of a main part illustrating a known sealing means, in which toner is stored on the right side of the container wall 4 in the figure, and from the left (external), for example, a conveying screw, etc. It is assumed that a shaft 6 for operating the is inserted into the container.

[0004] An annular protrusion 4' is formed on the wall portion 4.
A shaft 6 is arranged on a bearing 1 attached to this, and the bearing 1
A sealing member 2 is provided inside (on the right side in the figure) so as to surround the shaft 6.

[0005] The sealing member 2 is made of a suitable elastic material, and is required to be in strong contact with the surface of the shaft 6 at all times and not to impede rotation of the shaft 6. However, as mentioned above, toner has a particle size on the order of microns, so in order to seal it, the roundness of the hole surrounding the shaft 6 of the sealing member 2, the smoothness of the peripheral edge, etc. High precision machining is required, and at the same time, high precision machining of the outer periphery of the shaft 6 is also required.

[0006] This kind of situation not only causes an increase in the cost of the part, but also because the shaft and the sealing member move in phase, this accelerates wear and prevents long-term use. This also leads to an increase in costs.

Furthermore, due to the pressure of the toner in the container, toner inevitably enters the gap between the shaft and the sealing member, and this intruding toner is caused to spread between each other, the shaft, and the sealing member.
When rubbed by the sealing member, particles may grow into large lumps, and if these particles return to the toner container and mix with normal toner, the quality of the toner deteriorates, causing negative effects on image quality such as the occurrence of transfer defects. This cannot be avoided.

The present invention has been made to deal with this situation, and includes a sealing member located inside the bearing of the shaft passing through the toner container, and further inside the sealing member, a partition member that does not come into contact with the shaft. The purpose of this arrangement is to prevent direct contact between the toner and the sealing member, thereby stably maintaining the function of the sealing member over a long period of time.

[0009]

[Structure of the invention]

[Technical Means for Solving the Problems and Their Effects] In order to achieve the above object, the present invention provides a shaft that is rotatably attached to and passes through the wall of a powder container via a bearing. A sealing device having a sealing member disposed inwardly from the bearing, characterized in that a partitioning member is provided further inwardly from the sealing member to surround the shaft without contacting it. be.

[0010] With this configuration, powder may leak outside beyond the sealing member, or large lumps of powder generated near the sealing member may flow back to the powder side, resulting in deterioration of its characteristics. This can be effectively avoided.

[0011]

[Description of Embodiments] "Fig. 1" is a side cross-sectional view of essential parts showing an embodiment of the present invention, and parts corresponding to those in "Fig. 3" are given the same reference numerals. The explanation will be omitted unless necessary.

As shown in the figure, further inside the seal member 2 (on the right side in the figure) is a partition member 5 that passes through the shaft 6 with a hole that does not come in contact with the outer periphery of the shaft with as small a gap as possible. is provided, and therefore, the toner in the container does not move much closer to the seal member 2 than the partition member 5, and the seal member 2 is not directly subjected to the pressure of the toner in the container. A sheet material with a thickness of about 100 μm is suitable for the partition member, and it may also be molded integrally with the container 4 from resin.

The amount of toner that has passed through the partition member 5 and reached the seal member 2 over a long period of time is small, and is not directly subjected to pressure from a large amount of toner in the container. The position ensures that leakage to the outside is prevented. In addition, toner lumps that have grown into lumps due to being rubbed by the sealing member 2 are also isolated from the normal toner in the container, so they may mix with the normal toner and cause problems as described above. It is also possible to reliably prevent deterioration of image quality.

FIG. 2 shows another embodiment of the invention.

In the case of the illustrated device, a stopper 7 is rotatably engaged with the protrusion 4' of the container 4, and inside the stopper 7, from the left side in the figure, a bearing 1, a sealing member 2, a partition, etc. It is configured such that a member 5 is present, and further the protrusion 4' and the plug body 7
Openings 41 and 71 are formed in each of the openings 41 and 71, respectively.

Normally, the openings 41 and 71 are positioned in such a way that they do not overlap each other, and the stopper 7 is rotated at appropriate intervals so that the openings 41 and 71 are aligned. For example, toner and toner lumps accumulated inside the device are discarded through these openings, allowing long-term use.

[0017]

As explained above, according to the present invention, in a product equipped with a seal member that prevents leakage of powder from around a shaft penetrating the wall of a powder container, the seal member has a By configuring the structure so that there is no direct contact with the powder, it is possible to prevent powder from leaking from the sealing member over a long period of time, and to prevent large-sized lumps that form near the sealing member from flowing back into the container. It is also possible to prevent it from being mixed with normal powder. Therefore, by applying the present invention to an image forming apparatus using fine toner particles, it is effective to prevent deterioration of image quality.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view of a sealing device showing an embodiment of the present invention.

[Fig. 2] Side sectional view of a sealing device showing another embodiment.

[Fig. 3] Side sectional view showing the configuration of a known sealing device

[Explanation of symbols]

1 Bearing 2
Seal member 4
Toner container wall 5
Partition member 7
Plug body 41, 71 opening

Claims (3)

[Claims] 1. A sealing device comprising a shaft rotatably attached to and penetrating the wall of a powder container via a bearing, and a sealing member disposed inside the bearing of the shaft, A sealing device comprising a partition member that surrounds the shaft without contacting the shaft further inward than the seal member. 2. A stopper equipped with a sealing member and a partition member is rotatably mounted on the wall side of the powder container, and openings are formed in the stopper and the wall to which the stopper is mounted, respectively, A sealing device that allows both openings to selectively take a matching position and a non-matching position by rotating a plug. 3. The sealing device according to claim 1, wherein the powder is toner.