JPH0247680A - Developing roller - Google Patents

Abstract

PURPOSE:To decrease the number of parts and to reduce the cost by molding abutting parts for holding a constant distance from a drum integrally with a driving gear and a flange and fixing the driving gear and flange to a sleeve. CONSTITUTION:The driving gear 8 and flange 9 are molding parts and the abutting part 10 for holding the drum 1 and developing sleeve 6 at the ideal distance are formed. Then a force F is applied to a developing device 2 by a spring at all times, so torque is transmitted from a drum gear 11 to the driving gear 8 and when the developing sleeve 6 rotates, the abutting parts 10 and 10 on both sides secure the distance (a) between the developing sleeve 6 and drum 1 at all times. Consequently, the developing roller can be assembled with a small number of parts, so the cost is reducible.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a developing roller, and more specifically, in an electrophotographic apparatus composed of a drum and a developing device, the toner is conveyed to the drum surface and the developing roller is This relates to a developing roller for development.

[Prior art] Conventionally, this type of developing roller has a metal flange press-fitted into a stainless steel sleeve, and abutment rollers for maintaining the distance between the drum and the sleeve are attached to the shaft via ball bearings. A system was adopted in which a gear was incorporated to support and drive the sleeve.

In addition, relatively low-speed machines or machines with cartridge configurations do not require such durability, so
An aluminum sleeve was used, an aluminum flange was press-fitted into the sleeve, and then a cap was formed in place of the abutting roller, and the drive gear was fitted into the aluminum flange.

On the other hand, a magnet roller incorporated into a sleeve made of a non-magnetic material is configured so as not to come into contact with the sleeve or the flange, and is fixed with another member while also serving as magnetic pole alignment.

[Problems to be Solved by the Invention] However, the above-mentioned conventional technology has a problem in that the number of parts is large, leading to an increase in cost. especially,
If the distance tolerance between drum and sleeve is small,
In order to suppress component stacking errors, the precision of individual components must be extremely strict, which is a major factor in increasing costs. In addition, in order to ensure magnetic force, the magnetic roller is often set to a size that is just as large as the inner surface of the sleeve, so if the conventional support method uses multiple parts, the center of the sleeve and magnetic roller may be misaligned. Therefore, the inner surface of the sleeve and the magnet roller often rub against each other, resulting in problems such as a decrease in image quality and an increase in load torque.

The present invention attempts to solve these problems. That is, an object of the present invention is to provide a developing roller that can reduce the number of parts, reduce costs, provide high-quality images, and do not cause an increase in load torque. It is.

[Means for Solving the Problems] In order to achieve the above object, the present invention integrally molds an abutting portion on the drive gear and the flange to maintain a constant distance from the drum. The flange is fixed to the sleeve, or one abutting part is integrally molded to the drive gear, and the other is provided with a ring around the outer periphery of the sleeve.

[Function] According to the present invention, since the abutment part that maintains a constant distance from the drum is integrally molded with the drive gear, it is only necessary to press fit or glue the drive gear into the sleeve. If the butt part is also provided on the flange,
Similarly, it is only necessary to press fit or glue, or in the case of no such flange, it is sufficient to simply attach a ring to the outer periphery near the end of the sleeve, making it possible to achieve significant cost reductions. In addition, since the main parts are only two parts, it is easy to suppress stacking tolerances, and the optimum distance can be maintained during development. Furthermore, if the magnet roller is pivotally supported in the center hole of the molded gear, it becomes possible to assemble the magnet roller with high precision.

[Embodiment] FIG. 1 shows a first embodiment of the present invention, and shows a cross-sectional view of a process cartridge.

As is well known, the process cartridge is composed of a drum 1, a developing device 2, a cleaner, a charger, etc. (not shown);
I will explain in detail.

First, a developing container 3 holds and fixes a magnetic roller 4 via a magnetic pole alignment plate 5, and further rotatably holds a developing sleeve 6. Toner is filled in a chamber surrounded by an inner wall 3° and a sealing material 7, and the coating layer is regulated by a blade (not shown) and conveyed onto the drum 1.

Here, the developing sleeve 6 is a drawn or extruded aluminum tube, and a drive gear 8 is press-fitted or bonded to the other end of the tube. Further, the drive gear 8 and the flange 9 are molded parts, and the drum 1 and the developing sleeve 6 are set at an ideal distance a.
An abutting portion 10 is formed to maintain the position.

Since the developing device 2 is always subjected to a force F by a spring (not shown), when torque is transmitted from the drum gear 11 to the drive gear 8 and the developing sleeve 6 rotates, the abutting portions 1010 on both sides always apply the force F. A distance 1jla between the developing sleeve 6 and the drum 1 is guaranteed. At this time, the accuracy of the distance @a only needs to be considered based on the component accuracy of the developing sleeve 6, drive gear 8, and flange 9, so that variations are reduced and uniform image density can be obtained.

FIG. 2 shows a second embodiment of the invention.

A drive gear 28 having an abutting portion 10 is attached to the developing sleeve 26 , and is rotatably supported by the developing container 23 of the developing device 22 and the bearing member 25 .

A view of the bearing member 25 in the direction of arrow A is shown in FIG.
At 0, the outer peripheral surface of the developing sleeve 26 is directly received. Further, a ring 29 is incorporated around the outer periphery of the developing sleeve 26 near the end on the bearing member 25 side, and maintains the distance between the developing sleeve 26 and the drum 1. If the durable life is short, instead of the ring 29, a small piece of a resin sheet may be simply inserted and fixed between the developing sleeve 26 and the drum 1.

Further, the magnet roller 24 is rotatably supported on one side by the center hole of the drive gear 28 and supported at an appropriate angle by the D-cut hole 31 of the bearing member 25 on the other side. This D-cut hole 31 may be a rotation preventing means such as a square hole or a keyway.

As a result, the magnet roller 24 is fixed at a position with a suitable magnetic pole arrangement, and the developing sleeve 26 rotates around it.

According to this configuration, it can be assembled with a very small number of parts, which not only reduces costs, but also minimizes misalignment because the developing sleeve 26 and the magnet roller 24 are supported by the same member. It is possible. In particular, in the case of a small-diameter sleeve, it is necessary to make the outer circumference of the magnet roller 24 as large as possible due to the problem of magnetic force.
It is more effective because the gap between is smaller.

[Effects of the Invention] As explained above, according to the present invention, since the abutment part that maintains a constant distance from the drum is integrally molded with the drive gear, the drive gear can be press-fitted or glued into the sleeve. If a similar abutment is also provided on the flange, it can be press-fitted or glued in the same way, or if the flange does not have such an abutment, the outer periphery near the end of the sleeve All you have to do is attach the ring to the ring, making it possible to significantly reduce costs.
In addition, it is possible to easily provide a developing roller that can minimize variations in the distance between the sleeve and the drum, which greatly affect images. Also, if one side of the magnet roller is supported by the drive gear of the sleeve, and the other end is supported by providing a fitting part on the sleeve bearing member,
Furthermore, cost reduction and precision improvement of the magnetic roller support means can be achieved.

[Brief explanation of the drawing]

The drawings show embodiments of the present invention, and FIG.
FIG. 2 is a sectional view of the second embodiment, and FIG. 3 is an explanatory diagram of the bearing member viewed from the direction of arrow A in FIG. 2. 1...Drum, 2.22...Developer, 4.
24... Magnet roller, 6.26... Developing sleeve, 8.28... Drive gear, 9... Flange, 10... Abutting portion, 25...
...Bearing member, 29...Ring. 4 others figure

Claims (1)

[Scope of Claims] 1. In a developing roller including a sleeve made of a non-magnetic tube material, a magnetic roller, a drive gear, and a flange, an abutting portion for keeping the distance from the drum constant is A developing roller characterized in that the driving gear and the flange are integrally molded with each other, and the driving gear and the flange are fixed to the sleeve. 2. The developing roller according to claim 1, wherein one side of the magnetic roller is pivotally supported by a center hole of either the drive gear or the flange. 3. A developing roller including a sleeve made of a non-magnetic tube material, a magnetic roller, and a drive gear,
An abutment part for keeping a constant distance from the drum is integrally molded on the drive gear, and a ring for keeping a constant distance from the drum is attached to the outer periphery near the end of the sleeve. and a bearing member that receives the side opposite to the side to which the drive gear is fixed on the outer circumferential surface of the sleeve, and the bearing member simultaneously aligns the magnetic poles of the magnet roller. A developing roller.