JPH0473587B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a developing device, and particularly to a developing device in an electrophotographic copying machine, an electrostatic recording device, an electrostatic recording device, etc.

Prior Art In electrophotography, electrostatic recording, etc., there is a method for developing electrical latent images, such as electrostatic latent images, formed on the surface of various photoreceptors such as selenium photoreceptors and zinc oxide photoreceptors, or dielectric materials. Generally, a developing device is used which includes a developer tank containing a magnetic developer and a magnet roll for conveying the magnetic developer to a developing area.

The above-mentioned magnetic developer includes a two-component developer consisting of a ferromagnetic carrier such as iron powder, steel powder, or ferrite powder with a particle size of about 20 to 200 μm and a toner made of colored resin powder with a particle size of about 5 to 30 μm. A one-component magnetic toner consisting of particles with a particle size of about 5 to 50 μm, mainly composed of resin and magnetic powder, is often used. The magnet roll is constructed by arranging a permanent magnet member having a plurality of magnetic poles on the surface inside a cylindrical sleeve made of a non-magnetic material so that the sleeve and the permanent magnet member can rotate relative to each other. things are used.

As this developing device, for example,
As described in Japanese Patent Application Laid-open No. 30157, Japanese Patent Application Laid-Open No. 56-9772, etc., one or more developing magnet rolls are arranged inside the developing tank to face the photoconductor, and A magnet roll equipped with a conveying magnet roll for supplying developer, or as described in JP-A-52-26537, JP-A-55-159457, etc.
There are known devices in which only a developing magnet roll is provided inside the developing tank.

By the way, in a normal developing device, a bearing is used to support the side plate of the magnet roll developing device, and as mentioned above, the particle size of magnetic developer is small, ranging from several μm to several 100 μm.
To prevent magnetic developer from entering the bearing, JP-A-57
−86864, JP-A No. 58-57158, Utility Model Application No. 1983-
As shown in No. 150953, it has been proposed to attach a dustproof member such as an oil seal or felt to the end of the side plate. However, since the developing device contains fine powder magnetic developer as described above, it is virtually impossible to supply oil to the oil seal. Therefore, when the developing device is used for a long time,
When the oil seal wears out or breaks, fine particles of developer can enter the bearing, causing an accident where the magnet roll stops rotating.

Therefore, it is conceivable to provide a magnetic sealing means in the vicinity of the bearing portion, as described in, for example, Japanese Patent Application Laid-Open No. 120819/1982, but this poses a problem in that the structure becomes complicated.

Problems to be Solved by the Invention The present invention solves the above-mentioned problems, and even if the oil seal is worn or damaged, it can easily prevent magnetic developer from entering the bearing part in the side plate of the developing device. The object of the present invention is to provide a developing device that can reliably prevent this problem with its structure.

Means for Solving the Problems The present invention has a structure in which a flange having a shaft is fixed to the end of a cylindrical non-magnetic sleeve provided opposite to an image carrier on which a latent image is formed. In the developing device, a shaft is rotatably provided on a side plate via a bearing part, a permanent magnet member having a plurality of magnetic poles is provided in the sleeve, and an oil seal is disposed between the flange and the bearing part, In the developing device, the oil seal is fitted into a concave portion formed on the flange side of a collar fitted to a side plate, and a felt is interposed between the bearing portion and the collar surrounding the oil seal.

Embodiments Hereinafter, embodiments of the present invention will be described based on the drawings.

Here, FIG. 1 is a cross-sectional view of a developing device according to one embodiment, and FIG. 2 is an enlarged cross-sectional view of the main part of FIG. 1.

First, in Fig. 1, 1 is the developer tank, 2 is the developer tank 1
It is a two-component developer consisting of a ferromagnetic carrier and toner contained within. Reference numeral 3 denotes a photoreceptor drum serving as an image carrier; 4 a developing magnet roll disposed in the developer tank 1 facing the photoreceptor drum 3; a developing area A is formed between the roller and the photoreceptor drum 3; 5
is a cylindrical sleeve made of non-magnetic material, 6 is a permanent magnet member provided in the sleeve 5, and the sleeve 5 and the permanent magnet member 6 form a magnet roll 4.
Configure.

The permanent magnet member 6 includes a shaft 7 and a cylindrical permanent magnet 8 fixed around the shaft and having a plurality of magnetic poles on its surface. 9 is a doctor member, and 10 is a scraper member.

In the above configuration, the developer 2 adsorbed on the surface of the magnet roll 4 is conveyed in the same direction by rotating the sleeve 5 in the direction of arrow B, and its thickness is regulated by the doctor member 9. It is transported to the development area A. In the development area A, the developer 2 forms a magnetic brush, and by rubbing the surface of the photoreceptor drum 3 with this magnetic brush, the toner in the developer forms an electrostatic latent image (not shown). adhere to. Developer 2 after passing through development area A
is scraped off from the top of the sleeve 5 by the scraper member 10. Reference numeral 11 denotes a conveying magnet roll, which transfers the developer 2 to the developing magnet roll 4.
It is intended to be transported to

Next, the mounting structure of the developing magnet roll 4 of the above-mentioned developing device will be explained based on FIG. 2. In FIG. 2, reference numeral 12 denotes a shaft 14, 14' formed at the end of the flange 13 to which the sleeve 5 is fixed.
1 is a side plate of the developer tank 1, 15 is a bearing mounting hole provided in the side plate 14, and 16 is a bearing mounted in the bearing mounting hole 15, which rotatably supports the shaft 12. 17
18 is an oil seal, 18 is a collar that surrounds the oil seal 17 which is fitted into a recess formed on the flange 13 side, and 19 is a bearing 16 and an oil seal 17. This is a ring-shaped felt interposed between the collar 18 surrounding the collar 18.

20, 20' are bearings, and the permanent magnet member 6 is supported by flanges 13, 13' to which the sleeve 5 is fixed via the bearings 20, 20', and an oil seal 21 is fitted to the flange 13'. has been done. The other end 7a of the shaft 7 is fixed by a bolt 23 to a stopper member 22 fixed to the side plate 14'.

Effects of the Invention As described above, the developing device according to the present invention has a structure in which the shaft of the flange to which the sleeve is fixed is attached to the side plate with felt interposed between the bearing and the collar surrounding the oil seal. Because of the felt, the structure is simple, and even if the oil seal is worn or damaged and magnetic developer enters, the presence of the felt can prevent developer particles from entering the bearing. Furthermore, after the felt is inserted into the side wall from the flange side, a collar is further inserted to hold it in place, so it is easy to install and remove, and both sides are securely supported by the collar and bearings to prevent deformation. It can be prevented.

In the above embodiment, the present invention was applied to a developing magnet roll, but the same effect can be obtained even if the invention is applied to a conveying magnet roll.

As described above, the present invention can provide a developing device that can prevent magnetic developer from entering the bearing part in the side plate of the developing device with a simple structure, and is practical. It can be said that this invention is highly effective.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a developing device according to an embodiment of the present invention, and FIG. 2 is an enlarged sectional view of the main part of FIG. 1. 3...Photosensitive drum, 5...Sleeve, 6...
Permanent magnet member, 12... Ring, 14, 14'... Side plate, 16... Bearing, 17... Oil seal, 18
...Color, 19...Felt.

Claims (1)

[Claims] 1 A flange having a shaft is fixed to the end of a cylindrical non-magnetic sleeve provided opposite to an image carrier having a latent image formed on its surface, and this shaft is rotatably attached to a side plate via a bearing part. In the developing device, a permanent magnet member having a plurality of magnetic poles is provided in the sleeve, and an oil seal is disposed between the flange and the bearing portion, and a permanent magnet member is provided on the flange side of the collar fitted to the side plate. A developing device characterized in that the oil seal is fitted into the recessed portion, and a felt is interposed between the bearing portion and the collar surrounding the oil seal.