JPH06348121A - Developing device and process cartridge - Google Patents

Abstract

PURPOSE:To reduce a developing sleeve in size, miniaturize the whole device, and reduce the production cost by connecting a sleeve flange connected to the developing sleeve and a sleeve gear transmitting torque to the developing sleeve with a spline type or serration type joint. CONSTITUTION:A developing device is provided with a developing container storing a developer and a developer carrier rotatably supported via a bearing fitted to the developing container. The developer carrier is provided with a pipe-like developing sleeve 13, a sleeve flange 15 coupled with the inner periphery of at least one end section of the developing sleeve 13 and rotatably supported by a bearing, and a sleeve gear 17 coupled with the sleeve flange 15 and transmitting torque to the developing sleeve 13. The sleeve flange 15 and the sleeve gear 17 are connected by a spline type or serration type joint.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus used in a copying machine, a printer or the like using an electrophotographic system.

[0002]

2. Description of the Related Art Conventionally, in an image forming apparatus, process means such as a photoconductor as an image carrier, a charging device, a developing device, and a cleaning device are integrally incorporated in a common cartridge body which functions as a support. It is known that a process cartridge is constituted by the above, and the process cartridge can be attached to and detached from the image forming apparatus main body to improve the maintainability and serviceability of the image forming apparatus.

As shown in FIGS. 3 and 4, the developing device for such a process cartridge is constructed by arranging a developing roller 5 in a developing chamber 3 of a developing container 2 so as to be rotatable. Accommodates a magnet roller 6 composed of a magnet having a plurality of magnetic poles. Also, the developing roller 5
The developing blade 7 attached to the developing container 2 is in contact with the developing roller 5, and the developing roller 5 further includes left and right spacer rollers 10L and 10R, which are gap holding members, so as to have a certain gap between the developing roller 5 and the photoconductor 9. It is urged by the urging means (not shown) toward the photoconductor 9 through.

Toner, which is a developer, is supplied to the developing chamber 3 from a toner container (not shown) by a conveying means (not shown) or by dropping it from the inlet opening 11 of the developing chamber 3. Then, the toner in the developing chamber 3 is attracted to the N1 pole, which is one of the magnetic poles of the magnet roller 6, is agitated by the rotating developing roller 5, and is gradually charged.
Then, a part thereof is conveyed in the direction of the arrow in FIG. 3 with the rotation of the developing roller 5, enters between the developing blade 7 and the developing blade 7, and is strongly pressed against the developing roller 5 to be charged. In this way, the amount of charge of the toner is suddenly increased by the sliding contact with the developing blade 7, and the toner is conveyed to the outside of the developing chamber 3 as the developing roller 5 rotates.
The developing blade 7 charges the toner, increases the amount of the charge, and at the same time regulates the thickness of the toner layer on the developing roller 5.

Most of the developing roller 5 carrying the toner is made of a conductor such as aluminum alloy, and a bias electrode 12 has a cylindrical shape which constitutes the developing roller 5 at one end thereof as shown in FIG. It is incorporated in the inner circumference of the developing sleeve 13, and a developing bias is applied to the developing sleeve 13 from a phenomenon bias power supply unit (not shown) of the main body of the image forming apparatus.

Therefore, the toner carried by the developing sleeve 13 from the developing chamber 3 is applied to the photosensitive member 9 by the developing bias.
On the electrostatic latent image and the toner develops the electrostatic latent image. The so-called residual toner that has not been used for development is returned to the developing chamber 3 as the developing sleeve 13 rotates.

As described above, the developing sleeve 13 is rotatably arranged. This has a sleeve flange 15 fitted and fixed to the inner circumference of one end of the developing sleeve 13.
The bearing 16R is used for supporting, and the outer periphery of the spacer roller 10L described above fitted to the outer periphery of the other end is supported by the bearing 16L.

A sleeve gear 17 is fitted to the sleeve flange 15, and the sleeve gear 17 meshes with a drum gear 9a attached to the end of the photoconductor 9 to rotate the photoconductor 9 (in the direction of the arrow in FIG. 6). Development sleeve 1
Rotate 3.

The fitting hole of the sleeve gear 17 and the outer shape of the sleeve flange 15 have a so-called D cut or double D cut shape in which a part of the cylinder is cut off as shown in FIG. The rotation is stopped by.

[0010]

However, according to the above conventional example, when the developing roller 5 and the McNet roller 6 are reduced in diameter in response to the recent demand for downsizing in the personal market of copying machines and LBPs, , The following problem occurred.

That is, as described above, since the sleeve gear 17 and the sleeve flange 15 transmit the torque by the D cut or the double D cut, the allowable transmission torque becomes small due to the reduction in the diameter, and the sleeve is repeatedly used. There was a problem that the gear 17 slipped.

In order to solve this, it may be considered that only the diameter of the sleeve flange 15 is increased.
It is difficult to reduce the size of the gate portion 10g for injection molding of the spacer rollers 10R and 10L shown in FIG.

As another solution, it is conceivable to integrally form the sleeve flange 15 and the sleeve gear 17, but in this case, the bearing 16R cannot be incorporated between the sleeve gear 17 and the developing sleeve 13. Furthermore, if the bearing 16R is arranged outside the sleeve gear 17, the width of the developing device becomes wider, which violates the policy of reducing the diameter.

Further, it is conceivable to use a key or a pin for fitting the sleeve gear 17 and the sleeve flange 15, but this will increase the number of parts and the number of assembling steps.

An object of the present invention is to solve the above problems and to provide a developing device and a process cartridge capable of preventing the idle rotation of the sleeve gear even when the diameters of the developing roller and the magnet roller are reduced.

[0016]

SUMMARY OF THE INVENTION According to the present invention, the above-mentioned object is, first of all, in a developing device, rotatably supported by a developing container containing a developer and a bearing attached to the developing container. And a developer carrying member, wherein the developer carrying member is fitted to a pipe-shaped developing sleeve and an inner circumference of at least one end of the developing sleeve, and is rotated by the bearing. In a phenomenon device provided with a freely supported sleeve flange and a sleeve gear that is fitted to the sleeve flange and transmits torque to a developing sleeve, the sleeve flange and the sleeve gear are joints of spline type or serration type. Is achieved by being combined with.

Next, regarding the process cartridge,
This is achieved by integrally housing the developing device, the charging unit, the cleaning unit, the photoconductor, and the developing container in the cartridge main body, and detachably attached to the image forming apparatus.

[0018]

According to the present invention, the developer carrying member rotatably supported by the bearing attached to the developing container comprises a pipe-shaped developing sleeve, and at least one end of the developing sleeve is provided. The sleeve flange, which is fitted to the circumference and is rotatably supported by the bearing, and the sleeve gear, which is fitted to the sleeve flange, are coupled by using a spline-type or serration-type joint, thereby providing a small size. Even in the case of, the torque can be transmitted to establish and it can withstand repeated use.

[0019]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

<First Embodiment> First, a first embodiment of the present invention will be described with reference to FIG. Note that description of common points with the conventional example will be omitted.

FIG. 1 is a detailed view of the fitting of the sleeve flange and the sleeve gear according to the present invention. 12m in the figure
Spacer roller 10R is attached to the developing sleeve 13 having an outer diameter of m.
Is fitted and attached to the outer periphery, and the gap between the photoconductor (not shown) and the developing sleeve 13 is maintained at 200 to 400 μm.

The sleeve flange 15 has a step 15 having an outer diameter smaller than the inner diameter of the gate portion 10g of the spacer roller 10R.
a is provided and the protruding length is a spacer roller 1
It is larger than the thickness of the gate portion 10g of 0R. Therefore, even if the developing roller 5 moves in the thrust direction, the bearing 16R does not abrade the spacer roller 10R. The sleeve flange 15 is supported by the bearing 16R, but the fitting diameter is 6 to 8 mm.

Further, the small diameter portion d of the sleeve flange 15
Is one step thinner, 4-5 mm, and sleeve gear 1
It is fitted with 7. As shown in the right side of FIG. 1, the fitting portion forms two convex portions and concave portions on a cylinder to transmit torque. The convex portion of the sleeve flange 15 has a height of about 0.7 mm and a width of about 2 mm, and the outer shape is a concentric circle with the d portion. In the small-diameter portion d, the sleeve flange 15 and the sleeve gear 17 are fitted by statically fitting, H-js fitting is performed on the hole shaft surface, centering and backlash removal are performed. Therefore, the D section has some play. The sleeve gear 17 is provided with a boss portion 17a, and the fitting portion with the shaft is made longer than the tooth width to improve the allowable transmission force.

The sleeve flange 15 may be made of aluminum alloy, polyacetal (POM), polybutylene terephthalate (PBT), polyamide (PA) or other plastic. The sleeve gear 17 can be made of plastic such as polyacetal (POM), polybutylene terephthalate (PBT), polyamide (PA), and fluorine-containing polycarbonate (PC).

In this embodiment, the sleeve flange 15
Although there are two protrusions and recesses in the fitting portion of the sleeve gear 17 and the sleeve gear 17, the same effect can be obtained when the number of protrusions and recesses is three or four. In addition, the sleeve flange 15 and the sleeve gear 17
Although the small-diameter portion d has a static mating fit, the large-diameter portion D may have a static mating fit, and the small-diameter portion may have play.

In particular, when the sleeve gear 17 is manufactured by injection molding of plastic, the four recesses have a more uniform wall thickness, which makes it easier to obtain accuracy.

<Second Embodiment> Next, a second embodiment of the present invention will be described. Note that the description of the common points with the first embodiment will be omitted.

In the first embodiment, the spline type projections and recesses are formed in the fitting portion of the sleeve flange 15 and the sleeve gear 17, but in this embodiment, an involute serration joint may be used. Small diameter part of sleeve flange 15
The tooth bottom may be created by setting the module to 0.5 to 1 with the tooth bottom as the tooth bottom. The hub is created by creating internal teeth corresponding to the inside diameter of the sleeve gear. Since the gears are fitted to each other, a highly accurate coupling with a large transmission torque can be obtained.

Sleeve flange 15 and sleeve gear 1
When 7 is plastic injection molding, there is an advantage that the teeth can be created in the mold and the manufacturing cost can be reduced.
Further, in the case of selenation, the height of the teeth is lower than that of the spline, so that it is possible to suppress the occurrence of inaccuracy due to uneven thickness in injection molding.

If the developing device described in Embodiment 1 and Embodiment 2 is constructed as a process cartridge as shown in FIG. 2, the process cartridge can be downsized.

[0031]

As described above, according to the present invention,
The sleeve flange connected to the developing sleeve and the sleeve gear for transmitting torque to the developing sleeve are connected by using a spline-type or serration-type joint, whereby the diameter of the developing sleeve is reduced, and thus the entire apparatus is reduced. Miniaturization is achieved. Further, it does not increase the manufacturing cost.

[Brief description of drawings]

FIG. 1 is a detailed view of essential parts of a developer carrying member according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a process cartridge incorporating the developing device of the first or second embodiment of the present invention.

FIG. 3 is a sectional view of a conventional developing device.

FIG. 4 is a front view of the developing device of FIG.

5 is a view showing a fitting portion between a sleeve flange and a sleeve gear in the developing device of FIG.

6 is a perspective view showing a gate portion for injection molding of a spacer roller in the developing device of FIG.

[Explanation of symbols]

 1 Developing Device 2 Developing Container 5 Developing Roller (Developer Carrier) 13 Developing Sleeve 15 Sleeve Flange 17 Sleeve Gear

Claims (3)

[Claims] 1. A developing device comprising: a developing container for containing a developer; and a developer carrying member rotatably supported via a bearing attached to the developing container. Is a pipe-shaped developing sleeve, a sleeve flange fitted to the inner circumference of at least one end of the developing sleeve and rotatably supported by the bearing, and fitted to the sleeve flange, A developing device comprising a torque transmitting sleeve gear, wherein the sleeve flange and the sleeve gear are connected by a spline type or serration type joint. 2. The developing device according to claim 1, wherein the developing sleeve has a diameter of 12 mm or less. 3. A process cartridge in which at least a developing device, a charging means, a cleaning means, a photoconductor, and a developing container are integrally housed in a cartridge body and which is detachable from an image forming apparatus. A process cartridge, wherein the developing device according to claim 1 or 2 is used as the developing device.