JPH09325584A - Developing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a developing device capable of surely preventing the infiltration of toner to the bearing part of a stirring shaft with a simple constitution. SOLUTION: In the device, a stirring member 5 is provided with the stirring shaft 7 supported by a bearing means 6 arranged in a housing 4. In this case, a circular recessed part 9 is formed in the bearing means 6, and a rubber ring 12 equipped with a cup-like bellow 10 coming into contact with the recessed part 9 is provided on the stirring shaft 7, a step part 16 for positioning the rubber ring 12 is provided on the stirring shaft 7, and the rubber ring 12 is positioned by the bearing means 6, the step part 16 and a gear 13 arranged outside the housing 4 of the stirring shaft 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device having a stirring member for stirring a developer.

[0002]

2. Description of the Related Art Generally, a developing device is provided with a developer carrier for supplying the developer to a latent image carrier such as a photoconductor, a housing for accommodating the developer, and a rotatably mounted housing for stirring the developer. And a stirring member for supplying the developer to the developer carrying member. The stirring member has a stirring shaft supported by bearing means provided in the housing. If toner enters the part where the bearing means supports the stirring shaft, problems such as poor rotation of the stirring shaft and wear of the stirring shaft and bearing means occur.To avoid this problem, the bearing means should support the stirring shaft. The toner is sealed in the areas where it is present (Actual Fairness 7-50753, Special Fairness 8)
-20802, JP-A-3-189666). Specifically, in Japanese Utility Model Publication No. 7-50753, a stirring shaft is provided with a seal member in which an opening edge of a cup-shaped bellow is brought into contact with the housing side, and in JP-A-3-189666, a cup-shaped bellows is provided. A seal member whose opening edge is in contact with the stirring shaft is provided on the housing side, and in Japanese Patent Publication No. 8-20802, the above-mentioned two kinds of seal members are used together.

[0003]

[Problems to be Solved by the Invention]
In 50753 and Japanese Patent Publication No. 8-20802, in addition to the sealing member, an expensive member is used for the portion to which the bellows is brought into contact for sealing, thereby increasing the number of parts and increasing the structure. There are problems that it becomes complicated and the sealing cost increases. Further, in Japanese Patent Application Laid-Open No. 3-189666, there is a problem that the seal member is turned over due to the shaft backlash of the stirring shaft, and the toner enters.

The present invention solves the above problems and provides a developing device capable of reliably preventing toner from entering the bearing portion of the stirring shaft with a simple structure.

[0005]

According to the first aspect of the present invention,
A developer carrier for supplying the developer to the photoconductor, a housing for accommodating the developer therein, and a housing rotatably provided in the housing. The developer is agitated to load the developer on the developer carrier. And a stirring member for supplying the stirring member, wherein the stirring member has a stirring shaft axially supported by a bearing unit provided in the housing, wherein the bearing unit has a circular shape on the inner surface side of the housing. Is formed, the stirring shaft is provided with a cup-shaped bellows in contact with the recess, and a rubber ring that rotates integrally with the stirring shaft is provided.

According to a second aspect of the invention, in the developing device according to the first aspect, the rubber rings are installed at both ends of the stirring shaft in the housing.

According to a third aspect of the invention, in the developing device according to the first or second aspect, the stirring shaft is provided with a step portion for positioning the rubber ring.

According to a fourth aspect of the present invention, in the developing device according to the third aspect, a gear for rotationally driving the stirring shaft is provided at one end of the stirring shaft outside the housing, and the stirring shaft has the gear. The rubber ring provided on the gear side is characterized by being positioned by the bearing means, the step portion and the gear.

According to a fifth aspect of the present invention, in the developing device according to the third or fourth aspect, the step portion has a shape having a cylindrical body having an outer opening that covers the rubber ring together with the housing or the bearing. It is characterized by being.

[0010]

According to the first aspect of the invention, the inflow of the toner into the inside of the rubber ring is prevented by the contact of the bellows with the recess provided in the bearing means.

According to the second aspect of the invention, since the rubber rings are provided at both ends of the stirring shaft, the looseness of the stirring shaft is absorbed by the elasticity of the bellows.

According to the third aspect of the invention, the rubber ring is positioned and its movement is prevented.

According to the fourth aspect of the invention, the rubber ring can be positioned more reliably.

According to the invention described in claim 5, it is possible to more reliably prevent the toner from entering.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A developing device 1 of FIG. 1 showing an embodiment in which the present invention is carried out is provided with a developer carrier 3 for supplying a developer to a photoconductor 2 to develop an electrostatic latent image on the photoconductor 2. A housing 4 for storing the developer therein; and a stirring member 5 rotatably provided in the housing 4 for stirring the developer and supplying the developer to the developer carrier 3.

As shown in FIG. 2, the agitating member 5 has its both end portions in the housing 4 (only one side is shown in the drawing. The same applies hereinafter) by the bearing means 6 fitted and fixed to the housing 4. And a screw 8 provided on the stirring shaft 7 for stirring and conveying the developer as the stirring shaft 7 rotates. The bearing means 6 is made of resin POM, but may be made of other material instead of resin as long as it has good slidability and wear resistance.

The bearing means 6 is formed with a circular recess 9 on the inner surface side of the housing 4. The stirring shaft 7 has a recess 9
A base portion 11 of a rubber ring 12 having a cup-shaped bellows 10 abutting the opening edge of which is provided, the rubber ring 12 is rotated integrally with the stirring shaft 7 by the rotation of the stirring shaft 7. . The material of the rubber ring 12 is fluororubber, but cheaper chloroprene rubber may be used.

The stirring shaft 7 is inserted into the bearing means 6 and projects outside the housing 4 of the stirring shaft 7. The protruding end portion of the stirring shaft 7 is a spur gear which is rotationally driven by a driving means (not shown). 13 is fixed. The rotation speed of the stirring shaft 7 driven to rotate by the gear 13 is set to a relatively low speed of 500 rpm. When the number of rotations is 500 rpm or less, the rubber ring 12 is not deformed, and the intrusion of toner can be effectively prevented.

In order to position the base portion 11 of the rubber ring 12 in the axial direction of the stirring shaft 7, the stirring shaft 7 is provided with a flange-shaped step portion 16, and the rubber ring 12 is provided on the end surface of the step portion 16 at the base portion 11. It is positioned by the bearing means 6, the step portion 16 and the gear 12 by abutting the surface opposite to the surface having the bellows 10.

Although the step portion 16 is provided by the flange in this embodiment, the step portion 16 does not necessarily have to be formed by the flange, and the shaft diameter of the stirring shaft 7 is simply changed so as to form an appropriate step surface. Is also good.

The rubber ring 12 is an elastic member, and the bellows 10 must be pressed against the bearing means 6 to some extent in order to prevent the developer from entering the inside thereof. Is set so as not to become large enough to prevent the rotation of the stirring shaft 7.

On the side surface of the gear 13 on the housing 4 side, an annular abutting portion 14 that contacts the bearing means 6 is formed so that the end surface of the gear 13 does not contact the housing and the gear 13 An E ring 15 provided on the stirring shaft 7 is in contact with a side surface of the stirring shaft 7 opposite to the above side surface. This, together with the fact that the gear 13 is a spur gear, ensures the positioning of the gear 13. Therefore,
The movement of the stirring shaft 7 in the axial direction is restricted, and the frictional force of the bellows 10 with respect to the bearing means 6 is kept constant.

In FIG. 2, the gear 1 starts from the step surface of the stirring shaft 7.
If the length of 3 to the side surface on the E-ring side is L, this length L is determined by the gear 13, the abutment portion 14, the bearing means 6, the recess 9,
The size of each part of the rubber ring 12 is determined by the axial direction, and the size of each part is set on the condition of the friction force. Further, since the rubber rings 12 are installed at both ends of the stirring shaft 7 in the housing 4, the frictional force of the bellows 10 with respect to the bearing means 6 can also be obtained by appropriately adjusting the distance between the two end faces. Adjusted.

The depth of the recess 9 is set to 0.5 mm, and the deformation amount of the rubber ring 12 is set to about 0.5 mm.
In order to improve the adhesion between the concave portion 9 and the bellows 10, it is desirable that these contact portions be in a state close to a mirror surface, so a thin metal plate may be attached to the concave portion 9. Base 11
The positioning of is not limited to the stepped portion 16, but may be performed by forming a groove in the stirring shaft 7 and fitting the groove.

As shown in FIG. 3, the step portion 16 may have a cylindrical body 17 which covers the rubber ring 12 and has an opening on the outside. The distance d between the opening end of the cylindrical body 17 and the bearing means 6 is preferably small, and in this embodiment d
Is set to 0.5 mm. By providing such a cylinder 17, it is possible to more reliably prevent the toner from entering the rubber ring.

According to the present embodiment, the resin-made bearing means 6 having good wear resistance and slidability is used, and the frictional force between the rubber ring 12 and the bearing means 6 is adjusted as appropriate to make the stirring shaft 7 Since the rotation speed is relatively slow, the rubber ring 12
However, it does not deform due to frictional heat, and prevents a gap from being generated between the rubber ring 12 and the bearing means 6 due to abrasion, and prevents toner from entering inside the rubber ring.

[0027]

According to the invention of claim 1, claim 1
According to the above-mentioned invention, the inflow of the toner into the inside of the rubber ring is prevented by a simple structure in which the bellows are brought into contact with the concave portion provided in the bearing means and the assembly is easy and simple. Even if the rubber ring and the bearing means are worn, a small amount of toner can prevent the toner from entering the inside of the rubber ring.

According to the second aspect of the invention, since the rubber rings are provided at both ends of the stirring shaft, the looseness of the stirring shaft is absorbed by the elasticity of the bellows, and the bellows are turned up to the inside of the rubber ring. The toner is prevented from entering the toner.

According to the third aspect of the present invention, the rubber ring is positioned to prevent its movement, the pressure contact force of the rubber ring with respect to the bearing means is kept uniform, and the toner enters the inside of the rubber ring. To be prevented.

According to the fourth aspect of the present invention, the rubber ring is positioned more reliably, the pressure contact force of the rubber ring to the bearing means is kept uniform, and the toner is prevented from entering the inside of the rubber ring. .

According to the fifth aspect of the present invention, the amount of the developer contacting the rubber ring is reduced, so that the intrusion of the toner can be prevented more reliably.

[Brief description of drawings]

FIG. 1 is a schematic view showing an example of a developing device for carrying out the present invention.

FIG. 2 is an enlarged cross-sectional view of a main part of a developing device showing an embodiment of the present invention.

FIG. 3 is an enlarged sectional view of a main part of a developing device showing another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Developing device 2 Photoconductor 3 Developer carrying body 4 Housing 5 Stirring member 6 Bearing means 7 Stirring shaft 9 Recess 10 Bellow 12 Rubber ring 13 Gear 16 Step portion 17 Cylindrical body

Claims (5)

[Claims] 1. A developer carrier for supplying a developer to a photoreceptor, a housing for accommodating the developer therein, a housing rotatably provided in the housing, and stirring the developer to carry the developer carrier. And a stirring member that supplies the developer to the developing device, wherein the stirring member has a stirring shaft that is axially supported by bearing means provided in the housing. A circular recess is formed on the inner surface side, the stirring shaft has a cup-shaped bellows in contact with the recess, and a rubber ring that rotates integrally with the stirring shaft is provided. Developing device. 2. The developing device according to claim 1, wherein the rubber rings are installed at both ends of the stirring shaft in the housing. 3. The developing device according to claim 1, wherein:
The developing device, wherein the stirring shaft is provided with a step portion for positioning the rubber ring. 4. The developing device according to claim 3, wherein a gear for rotationally driving the stirring shaft is provided at one end of the stirring shaft on the outside of the housing, and the gear is provided on the gear side of the stirring shaft. The developing device, wherein the rubber ring is positioned by the bearing means, the step portion, and the gear. 5. The developing device according to claim 3, wherein
The developing device is characterized in that the stepped portion has a cylindrical body having an outer opening, which covers the rubber ring together with the housing or the bearing.