JP3056665B2 - Photoconductor device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photosensitive drum for a copying machine, a photosensitive drum for a printer, or another photosensitive drum having a photosensitive drum and a flange fitted to the photosensitive drum to rotate the photosensitive drum. The present invention relates to a photoconductor device such as a photoconductor provided for an image forming apparatus.

[0002]

2. Description of the Related Art A conventional photoreceptor device is disclosed, for example, in Japanese Utility Model Laid-Open Publication No. 61-155,631. As shown in FIGS. 6 and 7, this photoconductor device includes a plurality of rollers 101... That support the photoconductor drum 100 near both ends of the photoconductor drum 100, and is provided on an inner peripheral surface of the photoconductor drum 100. The photosensitive drum 100 is driven by a gear 104 meshing with the internal gear portion 103 of the flange 102 provided.

[0003] For example, see Japanese Patent Application Laid-Open No. 58-120265.
In FIG. 8, as shown in FIG. 8, an internal gear portion 202 of a flange 201 attached inside a central portion of the entire length of the photosensitive drum 200 and a gear 204 of a motor 203 provided inside the photosensitive drum 200 are disclosed. Is disclosed.

Further, as another conventional photoreceptor device, as shown in FIG.
There is a type in which a flange 302 having an internal gear portion 301 is fitted and provided, and the photosensitive drum 300 is rotated by a drive system including a small driving gear 303.

The flange 302 has an internal gear 301
And an internal gear support portion 304 formed on a plane perpendicular to the axis of the photosensitive drum 300 to support the photosensitive drum 300, and a rotary bearing portion 305 formed at the center position of the internal gear support portion 304.

The axially outer end 305a of the rotary bearing 305 is the outer end 301a of the internal gear 301.
The structure is located on the inside in the axial direction.

[0007]

However, in the above-mentioned conventional photoreceptor device, since the bearing and the like are located directly below the internal gear, foreign matter such as dust generated by abrasion of the internal gear falls on the bearing and the like. And the frictional resistance is increased, and the bearing portion is damaged, which causes uneven rotation, backlash, lock or increased load on the photosensitive drum.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to provide a friction between a rotary bearing and a rotary shaft due to foreign matter entering between the rotary bearing and the rotary shaft. It is an object of the present invention to provide a photoreceptor device capable of preventing an increase in resistance, damage to a rotary bearing portion, and uneven rotation of the photoreceptor drum due to the damage, play, lock and an increase in load.

[0009]

According to a first aspect of the present invention, there is provided a photoreceptor device for rotating a photoreceptor drum, the photoreceptor drum being fitted to the photoreceptor drum to rotate the photoreceptor drum. In the photoconductor device having a flange, the flange includes an internal gear portion, an internal gear support portion formed by a surface perpendicular to the axis of the photoconductor drum to support the internal gear portion, and an internal gear support portion. And a rotating bearing portion formed at the center position of the inner gear portion and the rotating bearing portion are formed so as to protrude outward in the axial direction from the inner gear supporting portion,
Also, the axially outer end of the rotary bearing portion is formed to extend further axially outward than the internal gear portion.

According to a second aspect of the present invention, there is provided a photoreceptor device having a photoreceptor drum and a flange fitted to the photoreceptor drum to rotationally drive the photoreceptor drum. In the apparatus, the flange is formed at a center position of the internal gear portion, an internal gear support portion formed by a surface perpendicular to the axis of the photosensitive drum to support the internal gear portion, and a central position of the internal gear support portion. And a rotating bearing part,
The internal gear portion and the rotary bearing portion are formed to protrude outward in the axial direction from the internal gear support portion, and a cover that covers the outer periphery of the rotary bearing portion between the rotary bearing portion and the internal gear portion supports the internal gear support. The cover is formed so as to protrude outward in the axial direction, and the outer end in the axial direction of the cover is formed to extend further outward in the axial direction than the internal gear portion.

According to a third aspect of the present invention, there is provided a photoreceptor apparatus having a photoreceptor drum and a flange fitted to the photoreceptor drum to rotationally drive the photoreceptor drum. In the apparatus, the flange is formed at a center position of the internal gear portion, an internal gear support portion formed by a surface perpendicular to the axis of the photosensitive drum to support the internal gear portion, and a central position of the internal gear support portion. The internal gear portion and the rotary bearing portion are formed so as to protrude outward in the axial direction from the internal gear support portion, and a rotary bearing is provided between the rotary bearing portion and the internal gear portion. A cover covering the outer periphery of the portion is formed to protrude inward in the axial direction from a drum rotation shaft support member such as a process frame or a main body frame provided outside the flange in the axial direction to support the rotation shaft of the photosensitive drum. That has been It is characterized in.

[0012]

According to the first aspect of the present invention, the axially outer end of the rotary bearing portion of the flange is formed to extend further axially outward than the internal gear portion.

Therefore, even when foreign matters such as dust generated due to wear of the internal gear portion fall, they only fall on the outer peripheral wall surface of the rotary bearing portion, and these foreign matters enter from between the rotary bearing portion and the rotary shaft. Can be prevented. For this reason, the frictional resistance between the rotating bearing portion and the rotating shaft is increased due to the invasion of foreign matter between the rotating bearing portion and the rotating shaft, the rotating bearing portion is damaged, and the rotational unevenness of the photosensitive drum due to the damage, backlash, An increase in lock and load can be prevented.

Further, in order to obtain this effect, it is only necessary to extend the rotary bearing portion further outward in the axial direction than the internal gear portion, so that the rotary bearing portion can be easily formed.

According to the second and third aspects of the present invention, the rotary bearing portion of the flange is provided with a cover for covering the outer periphery of the rotary bearing portion between the rotary bearing portion and the internal gear portion.

Therefore, even when foreign matter such as dust generated due to wear of the internal gear portion falls, the foreign matter only falls on the outer peripheral wall surface of the cover and enters the space between the rotary bearing portion and the rotary shaft. Can be prevented. For this reason, the frictional resistance between the rotating bearing portion and the rotating shaft is increased due to the invasion of foreign matter between the rotating bearing portion and the rotating shaft, the rotating bearing portion is damaged, and the rotational unevenness of the photosensitive drum due to the damage, backlash, An increase in locking and load can be reliably prevented.

Further, even if the foreign matter falls, only the outer peripheral wall surface of the cover is soiled and does not directly affect the rotary bearing portion. Therefore, it is possible to further prevent foreign substances from entering between the rotary bearing portion and the rotary shaft.

In order to obtain this effect, according to the second aspect, the cover is formed to protrude outward in the axial direction from the internal gear support portion, and the axially outer end of the cover is formed in the internal gear portion. It is formed so as to extend further outward in the axial direction.

That is, since the cover is formed on the flange and can be achieved only by changing the design of the flange, the cover can be easily formed.

According to a third aspect of the present invention, in order to obtain the above-mentioned effect, the cover is provided on the outer side of the flange in the axial direction to support the rotating shaft of the photosensitive drum. It is formed to protrude inward in the axial direction from the shaft support member.

As a result, the above-described effects can be obtained while maintaining the shape of the conventional flange, so that the present invention can be applied to a conventional flange.

[0022]

【Example】

[Embodiment 1] FIGS. 1 to 3 show an embodiment of the present invention.
This will be described below.

As shown in FIG. 2, the copying machine 1 provided with the photoreceptor device of the present embodiment has an original mounting table 2 made of hard transparent glass on the upper surface thereof. Has a scanner 3. Further, below the scanner 3, an image forming unit 13 having a photosensitive drum 14 as a center is provided.

The scanner 3 comprises a lamp unit 4, an automatic exposure sensor 5, mirrors 6 to 11, and a lens unit 12. In the scanner 3, a document placed on the document placing table 2 is irradiated with light from a lamp unit 4, and reflected light from the document is exposed on a rotating photosensitive drum 14 by mirrors 6 to 11 and a lens unit 12. Is done.

Around the photosensitive drum 14, the charger 1
5, developing tank 16, pre-transfer charger 17, transfer charger 1
8, peeling charger 19, cleaning unit 20,
A static elimination lamp 21 and a blank lamp (not shown) are provided. The photosensitive drum 14 is uniformly charged by corona discharge from the charger 15 prior to the exposure.

Light is emitted from a blank lamp in accordance with the sheet size to clear the electric charge in the non-image area.
The exposure forms an electrostatic latent image.

In the developing tank 16, the toner supplied from the toner hopper 22 and adjusted to a predetermined density by the toner density sensor 23 is stirred by the stirring roller 24 and charged to a predetermined charge amount. Then, the rotation of the photosensitive drum 14 causes the electrostatic latent image to be developed with toner.

The developed toner on the photosensitive drum 14 is
The image is transferred and visualized by a pre-transfer charger 17 and a transfer charger 18 onto a sheet conveyed from a sheet feeding system (not shown). A suction force acts between the sheet after the transfer and the photosensitive drum 14. Then, the peeling charger 19 applies an AC corona to the sheet to change the potential of the sheet to the photosensitive drum 1.
By lowering the suction force to the same potential as the surface of the photosensitive drum 4, the above-mentioned suction force is eliminated, and the paper is peeled off from the surface of the photosensitive drum 14 by its rigidity and by a peeling claw (not shown).

Next, the peeled sheet is sent to the fixing unit 26 via the transport unit 25, and the toner image is fixed and fixed on the sheet.

On the other hand, after the transfer, the toner remaining on the surface of the photosensitive drum 14 is removed by the cleaning unit 2.
The surface of the photosensitive drum 14 that has undergone the transfer process is cleaned by being scraped off and collected. Further, the residual potential of the photoconductor drum 14 is removed by irradiating light from the neutralization lamp 21 to lower the electric resistance of the photoconductor layer.

Each of the above-described means for forming an image includes:
It is controlled by the control unit 27.

As shown in FIG. 3, a drum flange with an internal gear (hereinafter, simply referred to as a "flange") 30 is fitted to the rear end of the photosensitive drum 14 by press-fitting and bonding. The photosensitive drum 14 is rotatably driven by the drive system 40 via the flange 30. The photosensitive drum 14, the flange 30, and the drive system 40 constitute a photosensitive device.

The drive system 40 includes a drive small gear 41 meshed with the internal gear portion 31 of the flange 30, a drive transmission gear system 42 connected to the drive small gear 41,
And a driving motor 43.

On the other hand, as shown in FIG. 1, the flange 30 has an internal gear portion 31 and an internal gear support portion formed by a surface perpendicular to the axis of the photosensitive drum 14 to support the internal gear portion 31. 32 and a rotary bearing 33 formed at the center of the internal gear support 32.

The internal gear portion 31 and the rotary bearing portion 33 are both formed to protrude outward in the axial direction from the internal gear support portion 32, and the axial outer end portion 33a of the rotary bearing portion 33 is formed.
Is formed to extend further outward in the axial direction than the outer end portion 31a of the internal gear portion 31.

The rotating bearing 33 is provided with a rotating shaft 34 of the photosensitive drum 14. The rotating shaft 34 is provided outside the flange 30 in the axial direction, and is fixed to a process frame 35 (drum rotating shaft supporting member) fixed to a main body frame 70 (drum rotating shaft supporting member) of the copying machine main body. I have. In this embodiment, in order to position the process frame 35 in the axial direction and prevent rattling, a positioning member projecting outwardly in the axial direction from the internal gear support portion 32 slightly outside the rotary bearing portion 33. 36 are formed.

With the photoconductor device having the above configuration,
When the driving motor 43 is driven, the driving force is transmitted to the internal gear portion 31 of the flange 30 via the driving transmission gear system 42 and the driving small gear 41, whereby
The photoreceptor drum 14 rotates around a rotation shaft 34.

When the photoreceptor drum 14 rotates, even if grease or shavings of the internal gear portion 31 drops or toner on the surface of the photoreceptor drum 14 drops, the outer peripheral wall surface 33b of the rotary bearing portion 33 also remains. It is possible to prevent foreign substances such as grease from entering from between the rotary bearing portion 33 and the rotary shaft 34 only by falling.

As described above, in the photoreceptor device of the present embodiment, the axially outer end 33a of the rotary bearing portion 33 of the flange 30 is formed to extend further axially outward than the internal gear portion 31. .

Therefore, even when foreign matter such as dust generated due to wear of the internal gear portion 31 falls, the foreign matter only falls on the outer peripheral wall surface 33b of the rotary bearing portion 33, and the foreign matter falls on the rotary bearing portion 33 and the rotary shaft 34. It can be prevented from invading from between.

For this reason, when the foreign matter enters between the rotary bearing portion 33 and the rotary shaft 34, the rotary bearing portion 33 and the rotary shaft 3
4 can prevent an increase in frictional resistance, damage to the rotary bearing portion 33, and uneven rotation of the photoconductor drum 14 due to the damage, play, lock, and an increase in load.

Also, in order to obtain this effect, it is only necessary to form the rotary bearing portion 33 so as to extend further in the axial direction than the internal gear portion 31, so that the rotary bearing portion can be formed easily.

In the present invention, the internal gear portion 31 and the rotary bearing portion 33 have a configuration formed so as to protrude outward in the axial direction from the internal gear support portion 32. This naturally includes a case in which the projection 33 projects inward from the internal gear support 32.

Embodiment 2 Another embodiment of the present invention will be described below with reference to FIGS. For the sake of convenience, members having the same functions as those shown in the drawings of the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

Flange 5 in photoreceptor device of this embodiment
As shown in FIG. 4, reference numeral 0 denotes an internal gear 31 and an internal gear formed by a surface perpendicular to the axis of the photosensitive drum 14 to support the internal gear 31, as in the first embodiment. Support 32
And a rotary bearing 51 formed at the center of the internal gear support 32.

The internal gear 31 and the rotary bearing 51 are formed so as to protrude axially outward from the internal gear support 32.

However, the axially outer end 51a of the rotary bearing 51 is located axially inside the outer end 31a of the internal gear 31.

Here, in this embodiment, in particular, a cover 52 covering the outer periphery of the rotary bearing portion 51 between the rotary bearing portion 51 and the internal gear portion 31 projects outward from the internal gear support portion 32 in the axial direction. The cover 52 has an axially outer end portion 52a that extends further axially outward than the internal gear portion.

When the photoreceptor drum 14 rotates, even if grease or shavings of the internal gear portion 31 falls, or if toner on the surface of the photoreceptor drum 14 drops, it falls onto the outer peripheral wall surface 52b of the cover 52. The grease and other foreign substances can be removed from the rotary bearing 51 and the rotary shaft 3
4 can be prevented from entering.

As described above, in the photoreceptor device of this embodiment, the cover 5 that covers the outer periphery of the rotary bearing 51 between the rotary bearing 51 and the internal gear 31 is provided on the rotary bearing 51 of the flange 50.
2 are formed.

Therefore, even when foreign matter such as dust generated due to wear of the internal gear portion 31 falls, the foreign matter only falls on the outer peripheral wall surface 52 b of the cover 52, and the foreign matter falls on the rotating bearing portion 51 and the rotating shaft 34. It can be prevented from invading from between. For this reason, the rotary bearing 51 of the foreign matter
The frictional resistance between the rotary bearing portion 51 and the rotary shaft 34 due to intrusion between the rotary shaft portion 34 and the rotary shaft portion 34, damage to the rotary bearing portion 51, and uneven rotation, play, lock and load of the photosensitive drum 14 due to the damage. Can be reliably prevented from increasing.

Further, even if the foreign matter falls, only the outer peripheral wall surface 52b of the cover 52 is soiled and does not directly affect the rotary bearing portion 51. Therefore, the rotating bearing portion 51 of the foreign matter and the rotating shaft 3
4 can be further prevented.

In order to obtain this effect, in this embodiment, the cover 52 is formed so as to protrude outward in the axial direction from the internal gear support portion 32, and the outer end 5 of the cover 52 in the axial direction is formed.
2a is formed to extend further outward in the axial direction than the internal gear portion 31.

That is, since the cover 52 is formed on the flange 50 and can be achieved only by changing the design of the flange 50, it can be formed easily.

As described above, in this embodiment, the cover 52 is formed on the flange 50, but is not necessarily limited to this. For example, as shown in FIG. It is also possible to form it so as to protrude inward in the axial direction from the process frame 35 or the main body frame 70 provided outside the flange 60 in the axial direction to support the rotating shaft 34.

That is, the rotary bearing 61 illustrated in FIG.
The outer end 61 a of the rotary bearing 51 is the outer end 5
1a and the outer end 31a of the internal gear portion 31 are located axially inward. The cylindrical cover 62 extending from the process frame 35 is provided on the outer peripheral wall surface 61 b of the rotary bearing 61, that is, at least the outer end 6 of the rotary bearing 61.
1a.

Here, the above-described process frame 35 refers to the photosensitive drum 14 or a process element necessary for executing an image forming process integrated with the photosensitive drum 14, that is, a frame portion of a process unit formed into a cartridge. In this process frame 3
5, the photosensitive drum 14 can be replaced.

Although the cover 62 is formed to extend from the process frame 35 in the example of FIG. 5, the cover 62 is moved from the body frame 70 of the copying machine 1 located further outside the process frame 35. It is also possible to extend (the extended state is not shown).

According to the above-described structure, even if the foreign matter drops, the outer peripheral wall surface 62b of the cover 62 is only stained, and
Has no direct effect. Therefore, the rotary bearing portion 6 of the foreign matter
Intrusion between the shaft 1 and the rotating shaft 34 can be further prevented.

In addition, since the above-described effects can be obtained while maintaining the shape of the conventional flange, the present invention can be applied to a conventional flange.

In the present invention, the cover 62 formed on the process frame 35 or the main body frame 70 described above.
Only needs to cover the outer end 61a of the rotary bearing 61 as a result. For example, as shown in FIG. 1, a component of the process frame 35 or a component (not shown) of the main frame 70 may be used. This is intended to include a case where the outer end 33a of the rotary bearing 33 is covered.

[0062]

As described above, in the photoreceptor device according to the first aspect of the present invention, the flange is formed by the internal gear portion and the surface perpendicular to the axis of the photoreceptor drum to support the internal gear portion. The internal gear support portion and the rotary bearing portion formed at the center position of the internal gear support portion, and the internal gear portion and the rotary bearing portion protrude outward in the axial direction from the internal gear support portion. In this configuration, the axially outer end portion of the rotary bearing portion extends further outward in the axial direction than the internal gear portion.

Thus, even when foreign matter such as dust generated by wear of the internal gear portion falls, the foreign matter only falls on the outer peripheral wall surface of the rotary bearing portion, and the foreign material falls from between the rotary bearing portion and the rotary shaft. Intrusion can be prevented. For this reason, the frictional resistance between the rotating bearing portion and the rotating shaft is increased due to the invasion of foreign matter between the rotating bearing portion and the rotating shaft, the rotating bearing portion is damaged, and the rotational unevenness of the photosensitive drum due to the damage, backlash, An increase in lock and load can be prevented.

Also, in order to obtain this effect, it is only necessary to form the rotary bearing portion further outward in the axial direction than the internal gear portion, so that there is an effect that the rotary bearing portion can be easily formed.

In the photoreceptor device according to the second aspect of the present invention, as described above, the flange is formed by the internal gear portion and the surface formed perpendicular to the axis of the photosensitive drum to support the internal gear portion. A gear support portion and a rotation bearing portion formed at a center position of the internal gear support portion, and the internal gear portion and the rotation bearing portion are formed to protrude outward in the axial direction from the internal gear support portion,
A cover covering the outer periphery of the rotary bearing portion is formed between the rotary bearing portion and the internal gear portion so as to protrude outward in the axial direction from the internal gear support portion, and the outer end of the cover in the axial direction is an internal gear. It is a configuration that is formed to extend further outward in the axial direction than the portion.

As a result, the rotating bearing portion of the flange has:
A cover that covers the outer periphery of the rotary bearing portion is formed between the rotary bearing portion and the internal gear portion.

Therefore, even when foreign matter such as dust generated by wear of the internal gear portion falls, the foreign matter only falls on the outer peripheral wall surface of the cover and enters from between the rotary bearing portion and the rotary shaft. Can be prevented. For this reason, the frictional resistance between the rotating bearing portion and the rotating shaft is increased due to the invasion of foreign matter between the rotating bearing portion and the rotating shaft, the rotating bearing portion is damaged, and the rotational unevenness of the photosensitive drum due to the damage, backlash, An increase in locking and load can be reliably prevented.

Further, even if the foreign matter falls, only the outer peripheral wall surface of the cover is soiled and does not directly affect the rotary bearing portion. Therefore, it is possible to further prevent foreign substances from entering between the rotary bearing portion and the rotary shaft.

In order to obtain this effect, the cover is formed so as to protrude axially outward from the internal gear support portion, and the outer end of the cover in the axial direction is more axially than the internal gear portion. Is formed so as to extend outside.

As a result, since the cover is formed on the flange and can be achieved only by changing the design of the flange, there is an effect that the cover can be easily formed.

In the photoreceptor device according to the third aspect of the present invention, as described above, the flange is formed by the internal gear portion and the surface formed perpendicular to the axis of the photoreceptor drum to support the internal gear portion. A gear support portion and a rotary bearing portion formed at a center position of the internal gear support portion, and the internal gear portion and the rotary bearing portion are formed to protrude outward in the axial direction from the internal gear support portion. And a cover for covering the outer periphery of the rotary bearing between the rotary bearing and the internal gear, wherein a cover is provided axially outside of the flange in order to support the rotary shaft of the photosensitive drum. It is a configuration formed to protrude inward in the direction.

Thus, the same effect as that of the cover of the second aspect is obtained, and the cover is rotated by a drum rotation shaft support member provided outside the flange in the axial direction to support the rotation shaft of the photosensitive drum. It is formed so as to protrude inward in the direction, so that the above-mentioned effect can be obtained while maintaining the shape of the conventional flange, so that there is an effect that it can be applied to the flange of the conventional product.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a structure of a photoconductor device according to an embodiment of the present invention.

FIG. 2 is an overall structural view showing a copying machine provided with the photoconductor device.

FIG. 3 is a perspective view showing a drive system of the photoconductor device.

FIG. 4 is a cross-sectional view illustrating a structure of a photoconductor device according to another embodiment of the present invention.

FIG. 5 is a cross-sectional view illustrating a structure of a photoconductor device according to still another embodiment of the present invention.

FIG. 6 shows a conventional example and is a perspective view of a photoconductor device.

FIG. 7 is a perspective view showing the photoconductor device with a part cut away.

FIG. 8 is a perspective view showing another conventional example, in which a photoconductor device is partially cut away.

FIG. 9 shows still another conventional example, and is a cross-sectional view of a photoconductor device.

[Explanation of symbols]

 Reference Signs List 14 photoconductor drum 30 flange 31 internal gear portion 31a outer end portion 32 internal gear support portion 33 rotating bearing portion 33a outer end portion 33b outer peripheral wall surface 34 rotation shaft 35 process frame (drum rotation shaft support member) 41 driving small gear 70 main body Frame (drum rotation shaft support member)

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yasuo Kitabatake 22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka Inside Sharp Corporation (72) Inventor Hideaki Kadowaki 22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka Sharp Corporation (72) Inventor Yoshikazu Harada 22-22 Nagaike-cho, Abeno-ku, Osaka-shi, Osaka Inside Sharp Corporation (56) References JP-A-53-133450 (JP, A) JP-A-3-192372 (JP, A (58) Field surveyed (Int. Cl. ⁷ , DB name) G03G 21/00 350-352 F16C 13/00-15/00 G03G 15/00 550 G03G 21 / 16-21/18

Claims (3)

(57) [Claims] 1. A photosensitive device having a photosensitive drum and a flange fitted to the photosensitive drum to rotate the photosensitive drum, wherein the flange supports an internal gear portion and the internal gear portion. The internal gear supporting portion formed at a plane perpendicular to the axis of the photosensitive drum, and a rotary bearing portion formed at a center position of the internal gear supporting portion. The portion is formed so as to protrude outward in the axial direction from the internal gear support portion, and the axially outer end of the rotary bearing portion is formed to extend further axially outward than the internal gear portion. Photoconductor device. 2. A photosensitive device having a photosensitive drum and a flange fitted to the photosensitive drum and rotatably driving the photosensitive drum, wherein the flange supports an internal gear portion and the internal gear portion. In order to have an internal gear support portion formed on a surface perpendicular to the axis of the photosensitive drum and a rotary bearing portion formed at the center position of the internal gear support portion, the internal gear portion and the rotary bearing portion are A cover formed so as to protrude outward in the axial direction from the internal gear support portion, and covering the outer periphery of the rotary bearing portion between the rotary bearing portion and the internal gear portion projects outward in the axial direction from the internal gear support portion. A photoreceptor device wherein the cover is formed and the outer end in the axial direction of the cover extends further outward in the axial direction than the internal gear portion. 3. A photosensitive device having a photosensitive drum and a flange fitted to the photosensitive drum and driving the photosensitive drum to rotate, wherein the flange supports an internal gear portion and the internal gear portion. The internal gear supporting portion formed at a plane perpendicular to the axis of the photosensitive drum, and a rotary bearing portion formed at a center position of the internal gear supporting portion. The portion is formed to protrude outward in the axial direction from the internal gear support portion, and a cover that covers the outer periphery of the rotary bearing portion between the rotary bearing portion and the internal gear portion supports the rotary shaft of the photosensitive drum. The photosensitive member device is formed so as to protrude inward in the axial direction from a drum rotation shaft support member provided outside the flange in the axial direction.