JPH11249397A - Particulate handling device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a particulate handling device whose production cost is reduced and whose performance deterioration is restrained by forming a groove for preventing particulates from intervening between the bearing surface of a slide bearing and a rotating body on the bearing surface. SOLUTION: A slide bearing G has wedged grooves G21, G22..., G2n and long grooves G31, G32..., G3n parallel with a shaft in addition to the bearing surface GB. Each of the wedged grooves G21, G22,..., G2n is formed as a wedged groove 21 by an inclined surface S1 formed by cutting an edge formed by the end face of the bearing G and the bearing surface GB, and an inclined surface linking the end of the surface S1 on the bearing surface GB side and a ridge part forming a boundary between the wedged grooves G21.... The wedged grooves G21, G22,..., G2n are formed at the end on the side of the bearing surface GB of the bearing G facing to a developer chamber. The long grooves G31, G32,..., G3n parallel with the shaft of the rotating body are formed on the bearing surface GB of the bearing G.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for handling fine particles, and more particularly to an apparatus for handling fine particles having a particle size of several .mu.m to several tens .mu.m, such as electrophotographic toner.

[0002] Specific examples of the particle handling device of the present invention include a developing device, a cleaning device, and a toner supply device of an electrophotographic apparatus.

[0003]

2. Description of the Related Art A developing device or a cleaning device of an electrophotographic apparatus is provided with a means for stirring or transporting a toner or a developer containing a toner and a carrier. These agitating and conveying means are rotatably supported by bearings, and are configured to agitate and convey the toner and the developer by rotational movement.

[0004]

However, in the bearing provided in a developer chamber or a toner chamber in a developing device or a cleaning device filled with fine particles such as toner,
These particles enter between the bearing and the rotating body supported by the bearing, that is, enter the bearing portion to deteriorate the performance of the bearing, that is, increase the friction between the rotating body and the bearing to increase the rotational speed. In addition, there has been a problem in that, for example, a reduction in the rotation speed and uneven rotation are caused, resulting in insufficient stirring and poor conveyance.

For this reason, a portion of the bearing facing the developer chamber or the toner chamber has been covered with a seal member to prevent toner from entering the bearing portion.

[0006] However, such countermeasures increase the number of parts and increase the cost, increase the number of steps for installing the seal member, and further increase the cost, and increase the torque due to the addition of the seal member. There was a problem. Further, the durability of the seal member is not so high, and the performance of preventing the toner from entering is deteriorated, and the above-mentioned problem caused by the entry of the toner into the bearing portion has not been completely solved.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-mentioned problems in an apparatus for handling fine particles, such as a developing device and a cleaning apparatus of an electrophotographic apparatus, and to reduce the manufacturing cost and handle the fine particles with little deterioration in performance. It is to provide a device.

[0008]

The object of the present invention is as follows.
In a particle handling apparatus in which a rotating body is provided in a storage chamber containing fine particles, at least one of the rotating bodies is rotatably supported by a slide bearing, and at least one of the rotating bodies is provided. The present invention is attained by a fine particle handling device, wherein a groove for preventing fine particles from intervening in a bearing portion between a bearing surface and the rotating body is formed on the bearing surface.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an electrophotographic developing device according to an embodiment of the present invention will be described.

(1) Developing Device FIGS. 1 and 2 show a developing device according to an embodiment of the present invention. FIG. 1 is a side sectional view of the developing device, and FIG. 2 is a plan sectional view of the developing device. is there.

The developing device 20 is arranged to face the photosensitive drum 10 and forms a developing area E with the photosensitive drum 10.

The outer shape of the developing device 20 is composed of a housing 21 and a lid 22 which form a developer chamber. In the housing 21, a developing sleeve 23, an impeller 25 for supplying the developer, developer conveying screws 27 and 28, etc. are provided. Is provided. The developing sleeve 23 is 0.01 to 5 m with respect to the photosensitive drum 10.
m, and ball bearings 23A,
The housing 21 is rotatably supported by 23B. A magnet body 24 having six magnetic poles is fixedly arranged inside the developing sleeve 23. Also, the developing sleeve 2
3, a developer regulating plate 26 is provided, and regulates the amount of developer conveyed on the developing sleeve 23. 2
Reference numeral 5 denotes an impeller for supplying the developer to the developing sleeve 23. Four blades are provided at an angle of 90 degrees corresponding to the entire length of the developing sleeve 23 as shown in FIG. The bearing is rotatable at 25A and 25B. Reference numerals 27 and 28 denote transport screws for stirring and transporting the developer, which are slide bearings 27A and 27, respectively.
B, 28A, and 28B rotatably mounted on the housing 21. The developer chamber 21B in which the developer transport screw 27 is disposed and the developer chamber 21C in which the developer transport screw 28 is disposed are separated by a partition wall 21A, and as shown by arrows in FIG. In the developer chambers 21B and 21C, the developer is transported in the opposite direction.

The developer chambers 21B and 21C contain a two-component developer composed of a toner and a carrier, and the toner is supplied to the developing device from a toner supply port 40 shown in FIG. The developer to which the supplied toner has been added is a developer transport screw 2
7, the developer is conveyed as indicated by an arrow, is scraped off by a paddle 271 provided on the developer conveying screw 27 at the right end of the developer chamber 21B in FIG. 2, and moves to the developer chamber 21C. The developer transferred to the developer chamber 21C is shown in FIG.
Is supplied to the developing sleeve 23 by the impeller 25 while moving to the left. It is needless to say that the developing device may contain a one-component developer containing no carrier.

The developer on the developing sleeve forms a developing ear in the developing area E by the action of the magnet 24, and develops the latent image on the photosensitive drum 10.

The developer that has passed through the developing area E is impeller 25
As a result, the developer is conveyed in the opposite direction to the case of supply and moves to the developer chamber 21C. In the developer chamber 21C, the developer is transported by a developer transport screw 28 as shown by an arrow, and the developer transport screw 28 is at the left end in FIG.
Is moved to the developer chamber 21 </ b> B by the paddle 281 provided at the second position. In the developer chamber 21B, toner is again supplied from the toner supply port 40, and toner is supplied to the developer.

The driving force of a rotating member such as the developing sleeve 23 is introduced from a gear G1. That is, the developing sleeve 23 is G
1 → G3, impeller 25 is G1, transfer screw 27 is G
1 → G2 → G4 → G5 → G6, the transfer screw 28 is G
They are driven by drive paths 1 → G2 → G4 → G5, respectively.

(2) Bearing The sliding bearing will be described with reference to FIGS. Impeller 25
The developer transfer screw 27 is rotatably supported by the housing 21 by the slide bearings 25A and 25B, and the developer transfer screw 28 is supported by the slide bearings 28A and 28B by the slide bearings 27A and 27B.

These sliding bearings 25A, 25B, 27
A, 27B, 28A and 28B have the structure shown in FIGS. These bearings are referred to below as G.

In addition to the bearing surface GB, the slide bearing G has wedge-shaped grooves G21, G22,... G2n and a long groove G parallel to the axis.
31, G32,... G3n. Wedge-shaped groove G2
Each of 1, G22,... G2n has a shape as described below. The wedge-shaped groove G21 will be described as an example. As shown in FIG. 3B, a slope S1 formed by cutting off an edge formed by the end face of the bearing G and the bearing face GB, an end of the slope S1 on the bearing face GB side, and wedge-shaped grooves. Ridges P1, P forming boundaries between G21,.
2,... Pn form a wedge-shaped groove G21 by the slopes S2 and S3. Wedge-shaped grooves G21, G22, ...
G2n is provided at the end of the bearing surface GB of the plain bearing G on the side facing the developer chamber.

The sliding bearing G further has long grooves G31, G32,... G3 parallel to the axis of the rotating body on its bearing surface GB.
n is formed.

Slide bearings 25A, 25B, 27A, 27
B, 28A and 28B are components provided in a developer chamber in which a developer composed of toner, which is fine particles of several μm to several tens μm, and a carrier of several tens μm is stored. The grooves prevent toner, which is fine particles, from entering the bearing and deteriorating the bearing action.

When a plain bearing having no grooves, that is, a bearing surface having a circumferential surface without grooves is used, the toner enters the bearing portion, and the entered toner is melted by frictional heat and pressure. As a result, it is fixed to the bearing surface and the rotating body to increase the friction therebetween. As a result, the rotation load increases, causing a decrease in the rotation speed and uneven rotation.

The wedge-shaped grooves G21, G22,... G2n have inclined surfaces S1, S2, S3 that open outward, so that when the rotating body rotates, the rotating body and the bearing surface of the slide bearing are rotated. A force for returning the developer that is going to enter the bearing portion between the outer portions acts, and the developer is in the sliding bearing G, that is, the bearing surface GB.
Is prevented from entering the part.

Also, long grooves G31, G32,... G3
n escapes the toner that has entered the bearing surface GB into these long grooves to prevent an increase in friction.

Although the embodiment of the present invention has been described above, the present invention is not limited to this embodiment, and various modifications are possible. , 28 is also effective if a groove is provided in a part of the rotating body supported by the slide bearing, for example, a groove is provided only in the rotary bearing.

The groove formed on the bearing surface of the plain bearing may be a wedge-shaped groove other than the illustrated shape, or a long spiral groove. Further, in addition to the developing device, the present invention can be applied to an electrophotographic cleaning device, an electrophotographic toner supply device, and the like.

Furthermore, the apparatus for handling fine particles of the present invention comprises:
It can also be used in fields other than electrophotography, for example, a pulverizer, a powder conveying device, and the like.

[0028]

According to the present invention, by providing a groove for preventing the fine particles from intervening in the bearing between the bearing surface of the bearing and the rotating body, the bearing performance is impaired by the fine particles interposed in the bearing. Is prevented, and phenomena such as a decrease in the number of rotations of the rotating body, uneven rotation and an increase in load torque are prevented.

[Brief description of the drawings]

FIG. 1 is a side sectional view of a developing device according to an embodiment of the present invention.

FIG. 2 is a plan cross-sectional view of the developing device shown in FIG.

FIG. 3 is a view showing a bearing used in the developing device shown in FIG. 1;

FIG. 4 is a perspective view of the bearing shown in FIG. 3;

[Description of Signs] 20 Developing device 25 Impeller 27, 28 Developer transport screw 25A, 25B, 27A, 27B, 28A, 28B, G
Slide bearings G21, G22, ... G2n Wedge-shaped grooves G31, G32, ... G3n Long grooves

Claims (5)

[Claims] 1. A particle handling apparatus in which a rotating body is provided in a storage chamber containing fine particles, wherein at least one of the rotating bodies is rotatably supported by a slide bearing in at least one of the rotating bodies. And a groove for preventing fine particles from intervening in a bearing portion between the bearing surface of the slide bearing and the rotating body, the groove being formed in the bearing surface. 2. The groove includes a wedge-shaped groove formed at an end of the bearing surface facing the storage chamber in an axial direction of the rotating body and opening toward the storage chamber. The particle handling apparatus according to claim 1, wherein 3. The particle handling device according to claim 1, wherein the groove includes a long groove parallel to an axis of the rotating body. 4. The fine particle handling apparatus according to claim 1, wherein the groove includes a long spiral groove. 5. The apparatus according to claim 1, wherein the fine particles are an electrophotographic developer.