JP3297516B2 - How to install rolling elements - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for mounting a rolling element.

[0002]

[0003]

2. Description of the Related Art An image forming apparatus such as a printer forms a latent image by selectively exposing a uniformly charged image carrier to an image carrier.
The latent image is visualized with toner, and the toner image is transferred to a recording medium to record an image. In such an apparatus, maintenance of each member can only be performed by a specialized service technician, which may be inconvenient for the user.

Therefore, the image carrier, the charger, the developing device,
The cleaning unit and the like are integrated into a cartridge to form a cartridge. By attaching and detaching the cartridge to and from the apparatus main body, the toner can be replenished and parts of the image carrier that have reached the end of their life can be replaced. Has been put to practical use.

Here, in the process cartridge, it is required that the size of the process cartridge be reduced in accordance with the size of the image forming apparatus. Therefore, a slide bearing has been used as a bearing for a rotating body such as an image carrier (for example, a photosensitive drum) and a developer carrier (for example, a developing sleeve).

However, when the process cartridge is mounted on the image forming apparatus and driven, a large torque is applied to rotating members such as the image carrier and the developer carrier. Therefore, when the rotating body is a slide bearing, a large load is applied because the sliding resistance of the rotating body when rotating is large. Therefore, a large motor that generates a large torque is required to drive the motor, and there is a problem that the cost is increased.

It is an object of the present invention to provide a method for mounting a rolling element, which enables further miniaturization.

Another object of the present invention is to provide a method of mounting a rolling element, which can reduce sliding resistance.

It is another object of the present invention to provide a method for mounting a rolling element which can improve image quality by improving rotation accuracy.

Another object of the present invention is to provide a method of mounting a rolling element which enables a motor provided in an apparatus main body to be reduced in size and noise by reducing driving torque.

Another object of the present invention is to provide a method of mounting a rolling element that can reduce the rotational load of the rotating body and rotate the rotating body with a small torque.

[0012]

[0013]

[0014]

A typical method according to the present invention for achieving the above object is to attach a rolling element to a process cartridge that can be mounted on an image forming apparatus main body.
In the method of mounting a rolling element, a rotatable rotating body,
A supporting member for supporting the rotating body, and in order to smoothly incorporate the rolling element between the cylindrical member and the supporting member so as to smoothly rotate the rotating body, The rotating body that regulates the position of the rolling element in the axial direction and the rotating direction is sucked from an intake hole provided at the rolling element regulating position of the rotating body and is attracted to the rolling element at the rolling element regulating position of the rotating body. A method of mounting a rolling element, wherein the holding member is mounted on the rotating body.

Another typical method according to the present invention is a method of attaching a rolling element to a process cartridge attachable to an image forming apparatus main body. A supporting member for supporting,
In order to smoothly rotate the rotating body,
When the rolling element is directly rotatably incorporated between the cylindrical member and the supporting member, the intake air provided at the rolling element regulating position of the holding member that regulates the position of the rolling element in the axial direction and the rotation direction of the rotating body. The rolling element is attached to the rolling element regulating position of the holding member by suction from a hole, and the rotating body is assembled to the holding member in that state.

[0016]

In the above construction, the rotation of the rolling element causes rolling resistance between the rotating body and the holding member, and the rotating body can be rotated with a small rotating torque.

Further, by regulating the position of the rolling element by a rotating body or a holding member, the bearing can be provided at a low cost without increasing the size of the bearing portion.

[0018]

Next, an embodiment of the present invention will be described in detail with reference to the drawings.

[First Embodiment] FIG. 1 is a schematic illustration of the configuration of an image forming apparatus in which a process cartridge according to the present invention is mounted, and FIGS. 2A and 2B are schematic illustrations of the configuration of the process cartridge. 3A is a side sectional view, FIG. 3B is an external perspective view, and FIG. 3 is an explanatory view of a bearing configuration of a developer carrier.

In the order of the description, first, the overall configuration of the apparatus in which the process cartridge is mounted will be described, then the configuration of each part of the image forming apparatus A and the process cartridge B will be described, and then the developer carrier (hereinafter referred to as " The bearing configuration of “sleeve” will be described.

This image forming apparatus A is, as shown in FIG.
An optical image based on image information is emitted from the optical system 1 to form a developer (hereinafter, toner) image on a photosensitive drum, which is an example of an image carrier. Then, the recording medium 2 is conveyed by the conveying unit 3 in synchronization with the formation of the toner image, and the toner image formed on the photosensitive drum in the image forming unit formed as a process cartridge B is transferred to the transfer unit 4.
To the recording medium 2. After that, the recording medium 2 is conveyed to the fixing unit 5, where the transferred toner image is fixed and discharged to the discharge unit 6.

As shown in FIG. 2, the process cartridge B constituting the image forming section rotates the photosensitive drum 7 and uniformly charges the surface thereof by the charging means 8. On the other hand, the light image from the optical system 1 is exposed to the photosensitive drum 7 via the exposure unit 9 to form a latent image, and the developing unit 10 forms a toner image corresponding to the latent image. After the transfer unit 4 transfers the toner image to the recording medium 2, the cleaning unit 11 removes the toner remaining on the photosensitive drum 7. Each component such as the photosensitive drum 7 is housed in a frame 12 constituting a housing to be made into a cartridge.

Next, the configuration of each part of the image forming apparatus A and the process cartridge B will be described.

<Image Forming Apparatus> First, the image forming apparatus A
Regarding the configuration of each part of, optical system, conveying means, transfer means,
The fixing unit and the cartridge mounting unit will be described in this order.

(Optical System) The optical system 1 irradiates a light image on the photosensitive drum 7 by irradiating light based on image information read from an external device or the like. As shown in FIG. 1, a laser diode 1b, a polygon mirror 1c, a scanner motor 1d, and an imaging lens 1e are housed in an optical unit 1a provided in the apparatus main body 13.

When an image signal is given from an external device such as a computer or a word processor, the laser diode 1b emits light according to the image signal and irradiates the polygon mirror 1c with image light. This polygon mirror 1c is rotated at high speed by a scanner motor 1d,
The image light reflected by the polygon mirror 1c forms an image forming lens 1
e and the photosensitive drum 7 rotating via the reflection mirror 1f
To form a latent image corresponding to image information by selectively exposing the surface of the drum 7 to light.

(Recording Medium Conveying Means) Next, the conveying means 3 for conveying the recording medium 2 (for example, recording paper, OHP sheet, cloth or thin plate) will be described. First, the apparatus main body 13 has a mounting portion for the cassette 3a. Then, the recording medium 2 in the cassette 3a mounted on the mounting portion is fed one by one from the upper portion to the pair of registration rollers 3c1 and 3c2 by the pickup roller 3b.
1, 2c so that the recording medium 2 is synchronized with the image forming operation.
To the image transfer unit. Then, the recording medium 2 on which the image has been transferred by the image transfer unit is transported by the transport roller 3 d
e, the recording medium 2 is conveyed to the fixing means 5, and the fixed recording medium 2 is discharged to a discharge section 6 provided at the upper portion of the apparatus by discharge rollers 3f.

(Transfer Unit) The transfer unit 4 transfers the toner image formed on the photosensitive drum 7 in the image forming unit onto the recording medium 2, and the transfer unit 4 of this embodiment is, as shown in FIG. , And the transfer roller 4. That is, the recording medium 2 is pressed against the photosensitive drum 7 of the mounted process cartridge B by the transfer roller 4, and a voltage having a polarity opposite to that of the toner image formed on the photosensitive drum 7 is applied to the transfer roller 4. The toner on the photosensitive drum 7 is transferred to the recording medium 2.

(Fixing Means) The fixing means 5 fixes the toner image transferred to the recording medium 2 by applying a voltage to the transfer roller 4. As shown in FIG. 1, the configuration includes a driving roller 5a that is driven and rotated, and a fixing roller 5c that has an internal heater 5b and that is pressed against the driving roller 5a and is driven to rotate. That is, when the recording medium 2 onto which the toner image has been transferred in the image forming unit passes between the driving roller 5a and the fixing roller 5c, pressure is applied by the pressing of both rollers 5a and 5c, and the heat generated by the fixing roller 5c is generated. Heat is applied to the recording medium 2 and the toner on the recording medium 2
Established in

(Process Cartridge Mounting Means) A cartridge mounting means for mounting the process cartridge B is provided in the image forming apparatus A. The mounting and dismounting of the process cartridge B with respect to the apparatus main body 13 is performed by opening the openable cover 14. That is, the device body 13
An openable cover 14 that can be opened and closed by a hinge 14a is attached to the upper part of the cover. When the opening / closing cover 14 is opened, a cartridge mounting space is provided in the apparatus main body 13 and left and right guide members G1
(Only one is shown) is attached. The left and right guide member G1 is provided with a guide for inserting the process cartridge B. The process cartridge B is inserted along the guide, and the open / close cover 14 is closed to mount the process cartridge B on the image forming apparatus A. I am trying to do it.

<Process Cartridge> Next, the structure of each part of the process cartridge B mounted on the image forming apparatus A will be described.

The process cartridge B is provided with an image carrier and at least one process means. Here, examples of the process means include a charging means for charging the surface of the image carrier, a developing means for forming a toner image on the image carrier, and a cleaning means for cleaning toner remaining on the surface of the image carrier. In the process cartridge B of this embodiment, as shown in FIG. 2, a charging unit 8, an exposure unit 9, a developing unit 10, and a cleaning unit 11 are arranged around an electrophotographic photosensitive drum 7 as an image carrier. The unit is covered with a housing made of the frame body 12 composed of the first frame body 12a and the second frame body 12b, is integrated, and is configured to be detachable from the apparatus main body 13.

Next, the structure of each part of the process cartridge B will be described in the order of the photosensitive drum 7, charging means 8, exposure part 9, developing means 10, and cleaning means 11.

(Photosensitive Drum) The photosensitive drum 7 according to the present embodiment is a drum base 7b made of cylindrical aluminum.
And an organic photosensitive layer 7c is applied to the outer peripheral surface of the substrate. The photosensitive drum 7 is rotatably mounted on the frame 12, and the driving force of a drive motor provided on the apparatus main body side is transmitted to a flange gear fixed to one longitudinal end of the photosensitive drum 7 as described later. Then, the photosensitive drum 7 is rotated in the direction of the arrow in FIG. 1 according to the image forming operation.

(Charging Means) The charging means is for uniformly charging the surface of the photosensitive drum 7, and in this embodiment, a charging roller 8 is rotatably mounted on the frame 12, so-called contacting means. A charging method is used. The charging roller 8 is formed by providing a conductive elastic layer on a metal roller shaft 8a, further providing a high-resistance elastic layer thereon, and further providing a protective film on the surface thereof. The conductive elastic layer is formed by dispersing carbon in an elastic rubber layer such as EPDM or NBR.
It serves to guide the bias voltage supplied to a. The high-resistance elastic layer is made of urethane rubber or the like, and contains a small amount of conductive fine powder as an example. Even when a charging roller having high conductivity such as a pinhole of the photosensitive drum 7 faces, It functions to limit the leak current to the photosensitive drum 7 to prevent a sharp drop in the bias voltage. The protective layer is made of N-methylmethoxylated nylon so that the plastic material of the conductive elastic layer and the high-resistance elastic layer does not touch the photoconductor drum 7 and deteriorate the surface of the photoconductor drum 7. Works.

The charging roller 8 is moved to the photosensitive drum 7
During image formation, the charging roller 8 rotates following the rotation of the photosensitive drum 7, and at this time, a DC voltage and an AC voltage are applied to the charging roller 8 in a superimposed manner so that the photosensitive drum 7 Charge the surface uniformly.

(Exposure Unit) The exposure unit 9 exposes the surface of the photosensitive drum 7 uniformly charged by the charging roller 8 to a light image irradiated from the optical system 1 and exposes the surface of the drum 7 to an electrostatic latent image. For forming the cartridge frame 1
An exposure unit is formed by providing an opening 9 for guiding the light image on the upper surface of the light source 2.

(Developing Means) As shown in FIG. 2, the developing means 10 has a toner reservoir 10a for accommodating toner, and a toner feed member 10b which rotates in the direction of the arrow to feed the toner into the toner reservoir 10a. Is provided. Further, a developing sleeve 10d which has a magnet 10c inside and forms a thin toner layer on the surface by rotating is provided at a small distance from the photosensitive drum 7.

When a toner layer is formed on the surface of the developing sleeve 10d, triboelectric charges sufficient to develop the electrostatic latent image on the photosensitive drum 7 are obtained by friction between the toner and the developing sleeve 10d. Further, a developing blade 10e is provided to regulate the layer thickness of the toner.

(Cleaning means) Cleaning means 1
As shown in FIG. 2, the configuration of the cleaning device 11 includes a cleaning blade 11a for contacting the surface of the photosensitive drum 7 and scraping off the toner remaining on the drum 7, and the cleaning blade 11a for scooping the scraped toner. It comprises a squeeze sheet 11b, which is located below the blade 11a and is in weak contact with the surface of the photosensitive drum 7, and a waste toner reservoir 11c for storing the scooped waste toner.

Incidentally, reference numeral 20 denotes a handle, and 21 denotes a guide, which engages with the guide G1 on the main body side when mounted on the apparatus main body.

(Bearing Configuration of Developing Sleeve) Next, a bearing configuration of the developing sleeve 10d will be described with reference to FIG. In the developing sleeve 10d used in this embodiment, the surface of the aluminum cylindrical member is roughened by sandblasting or the like, and a conductive paint in which a pigment is dispersed is applied thereon. Therefore, when a toner layer is formed on the surface of the developing sleeve 10d, a frictional charge between the toner and the developing sleeve 10d provides a triboelectric charge sufficient to develop the electrostatic latent image on the photosensitive drum 7.

The driving force is transmitted from the driving motor M provided in the image forming apparatus main body to the photosensitive drum flange gear 7a via the gear 21 provided in the apparatus main body, and to the sleeve gear 10e via the drum flange gear 7a. Then, the photosensitive drum 7 and the developing sleeve 10d rotate (FIG. 6). Here, in the present embodiment, the developing sleeve 1
Od and its end flange 10f are held via a ball 10i to a sleeve cap 10g, which is a holding member of the rotating body. That is, a groove 10h1 is provided circumferentially on the outer periphery of the flange 10f fitted to the end of the developing sleeve 10d, and a plurality of recesses 10h2 facing the groove 10h1 are provided on the inner periphery of the sleeve cap 10g. Between the groove 10h1 and the recess 10h2, a plurality of small-diameter rolling elements 10i are rotatably provided. That is, in this embodiment, the role of the inner ring of the bearing is
0f, and the sleeve cap 10g doubles as the outer ring. Note that the sleeve cap 10g is the housing 1
2 is held.

The material of the sphere 10i can be appropriately selected, for example, from metal or abrasion-resistant rigid plastic in consideration of the material of the flange and the sleeve cap. In the above-described embodiment, the groove 10h is formed in the flange 10f.
1. Although an example in which the recess 10h2 is provided in the sleeve cap 10g is shown, the recess 10h2 is provided in the flange 10f.
The groove 10h1 may be provided in the sleeve cap 10g.
Further, even if the groove is not provided in the entire circumferential direction, a concave portion may be provided in a portion where the plurality of spheres 10i are provided in the entire circumferential direction. In this embodiment, the material of the flange 10f and the sleeve cap 10g is a rigid plastic. However, the material is not limited to this and may be a metal such as stainless steel.

By adopting the above bearing configuration,
When the developing sleeve 10c rotates, the ball 10i rotates freely, the friction coefficient becomes lower than that of the plain bearing, a large torque reduction can be realized, and the apparatus can be made smaller than when a conventional ball bearing is incorporated.

Incidentally, the bearing configuration is not limited to the above-described configuration. Second Embodiment Hereinafter, another bearing configuration will be described. Members having the same functions as in the first embodiment are denoted by the same reference numerals.

[Second Embodiment] Next, a second embodiment will be described with reference to FIG. FIG. 4 is a vertical sectional view of a part of the developing means.

In this embodiment, a cylindrical roller 10j is used instead of a sphere (circular sphere). The roller 10j is rotatably held by roller holding portions 10k provided at a plurality of locations over the inner peripheral surface of the sleeve cap 10g. The roller holding portion 10k includes vertical plates 10k1 provided to face each other,
k2 is a shaft 10j1, j provided at the end of the roller 10j.
2 is rotatably held. By doing so, the roller 10j can be easily held on the sleeve cap 10g, and the same effect as in the first embodiment can be obtained with respect to a reduction in torque. In addition, this embodiment is not limited to the developing sleeve 10d, and can be suitably applied to the attachment of, for example, a photosensitive drum, a charging roller, and the like if it is a rotating body. Further, the roller holding portion 10 is attached to the flange 10f.
k may be attached.

Third Embodiment Next, a third embodiment will be described with reference to FIG. In the first and second embodiments, an example is shown in which a rotating member such as the developing sleeve 10 and / or the photosensitive drum 7 is rotatable with its outer peripheral surface held relative to the cartridge frame 12. Was. On the other hand, this embodiment shows a case where the inner peripheral surface of the rotating member is held.

A groove 10f2 is provided in the inner diameter portion 10f1 of the flange 10f fitted to the end of the developing sleeve 10d, and a dowel (shaft) 10m extending from the side plate of the toner frame 12a which is a part of the cartridge frame 12 to the inside. A plurality of recesses 10m1 are formed on the surface facing the groove 10f2, and the grooves 10f2, 1
Roll the ball 10i between 0m1. The sphere 10i may be a roller as in the second embodiment, and may be made of a metal or a hard plastic having lubricity. Even with such a configuration, the same effect as that of the first and second embodiments described above such as torque reduction can be obtained.

[Fourth Embodiment] Next, FIG. 6 and FIG.
A fourth embodiment will be described with reference to FIG. This embodiment shows a bearing configuration of the photosensitive drum 7. A drum flange gear 7a is provided at the longitudinal end of the photosensitive drum 7.
Is fixed to the shaft portion 7a1 of the flange gear 7a.
Is held by a holder 15 which is a holding member fixed to a frame 12b of the process cartridge B with a screw or the like (not shown) via a plurality of balls 16 which are rolling elements.

The shaft 7a1 of the flange gear 7a is provided with a plurality of recesses 7a2 for regulating the position of the ball 16 over the rotation direction of the photosensitive drum 7 (FIG. 7).
(See (a) and (b)). Also, assembling method of the bearing part
The photosensitive drum 7 is set up so that the flange gear 7a faces upward, the ball 16 is incorporated into the concave portion 7a2, and the holder 16 is set on the frame 12b while maintaining its posture.
Is to be assembled.

Thus, by providing the ball 16 between the photosensitive drum 7 and the holder 15 that rotatably holds the photosensitive drum 7, the photosensitive drum 7 can be formed more easily than when a conventional plain bearing is used. The driving torque can be reduced by about 20 to 50%. A concave portion 7a2 in which the inner ring and the outer ring of the rolling bearing are shared by the shaft portion 7a1 and the holder 15, and the axial and rotational positions of the photosensitive drum 7 are regulated in the shaft portion 7a1.
Thus, it is possible to reduce the size of the apparatus at a lower cost than when a conventional rolling bearing is incorporated.

In this embodiment, the driving force of the motor M provided in the apparatus main body is transmitted to the flange gear 7a via the gear 21. Then, the flange gear 10f of the developing sleeve 10d is further rotated via the flange gear 7a.
10 g is a spacer roller, and the developing sleeve 1
The gap between Od and the photosensitive drum 7 is maintained. Further, the photosensitive drum 7 has a photosensitive member 7c on the surface of the sleeve 7b.
Is applied. 7a3 and 10f1 are gear portions. Even if the gear portions 7a3 and 10f1 have flat teeth,
A helical tooth may be used, but with a helical tooth, drive transmission is performed more smoothly.

[Fifth Embodiment] In the above-described fourth embodiment,
A concave portion 7a2 is provided in a shaft portion 7a1 of
6 and FIG. 9 (a).
-As shown in (b), the position of the ball 16 may be regulated by the holder 15 as a holding member. 8 and 9
In the embodiment shown in FIGS. 7A and 7B, the inner diameter portion 15b of the holder 15 is provided with a concave portion 15a corresponding to the number of balls 16 to be loaded in the rotation direction of the photosensitive drum 7. The ball 16 is incorporated in the recess 15a, and the holder 15 is assembled to the shaft 7a1 of the photosensitive drum 7 set in the frame 12b.

In this case, the same effect as in the case of the fourth embodiment can be obtained.

[Sixth Embodiment] As shown in FIG.
As in the third embodiment, a positioning shaft 17 fitted and fixed to the frame 12b is mounted not only on the holder as the holding member of the rotating body but also on the flange gear 7a attached to the end of the photosensitive drum 7 as the rotating body, as in the third embodiment. The same applies to the case where the photosensitive drum 7 is held by being fitted. In this embodiment, a sphere 16 is mounted on a concave portion 7a2 provided at a plurality of positions in the inner diameter portion of the flange gear 7a in the rotation direction of the photosensitive drum 7, the photosensitive drum 7 is set on the frame 12b, and the positioning shaft 17 is flanged. The gear 7a is configured to be fitted into the hole and assembled.

Also in this case, the rolling torque of the photosensitive drum 7 is reduced by the rolling of the ball 16. Ball 16
The position of the rotation axis and the rotation direction of the photosensitive drum 7 is regulated by the concave portion 7a2 of the flange gear 7a.

[Seventh Embodiment] The embodiment shown in FIG. 11 has substantially the same structure as the sixth embodiment, except that the position of the ball 16 is regulated by the positioning shaft 17.
That is, in this embodiment, a mounting recess 17a for the ball 16 is provided on the outer diameter portion of the positioning shaft 17 mounted on the frame 12b, and the position of the mounted ball 16 is regulated by the recess 17a. Thus, even if the recess 17a is provided in the positioning shaft 17, the same effect as in the sixth embodiment can be obtained.

[Eighth Embodiment] In the fourth to seventh embodiments described above, the ball 16 is mounted in the concave portion provided in the rotating body or the holding member, thereby restricting the position of the rotating body in the axial direction and the rotating direction. Although an example in which the processing is performed has been described, a configuration as illustrated in FIGS. 12 and 13A and 13B may be employed. That is, the shaft portion 7a1 of the flange gear 7a is composed of a large-diameter portion and a small-diameter portion, and a plurality of recesses 7a6 are provided in the step portion 7a4 in the rotation direction of the photoconductor 7 (FIG. 13A).
(B)). On the other hand, a holder 15 for holding the shaft 7a1
Is also provided with a step 15b. To assemble this, the ball 16 is placed on the concave portion 7a6 with the photosensitive drum 7 standing with the flange gear 7a facing upward, and the
After setting to 2b, the holder 15 is assembled to the shaft portion 7a1.

In this way, the position of the ball 16 in the rotational direction of the photosensitive drum 7 is regulated by the concave portion 7a3,
The position of the photosensitive drum 7 in the rotation axis direction is regulated by the concave portion 7a3 and the step portion 15b. Ball 1
The rotation torque of the photosensitive drum 7 can be reduced by the interposition of the photosensitive drum 6.

Ninth Embodiment The ninth embodiment shown in FIG. 14 has substantially the same structure as the eighth embodiment, except that the recess shown in the eighth embodiment is provided on the holder 15 side. That is, in this embodiment, the inner diameter of the holder 15 is constituted by a large diameter portion and a small diameter portion, and a plurality of concave portions 15c are provided in the step portion. On the other hand, the shaft portion 7a of the flange gear 7a attached to the photosensitive drum 7
In order to assemble the step portion 7a4, a ball 16 is placed on the concave portion 15c, and the ball portion 16 is attached to the shaft portion 7a1 of the photosensitive drum 7 set in the frame 12b from below.
Even in this case, the same effects as in the eighth embodiment can be obtained.

[Tenth Embodiment] In the above embodiment, the ball 1
The example in which the position of the rotating body in the rotation direction is restricted by mounting the rotating member 6 in the concave portion has been described. However, as shown in FIGS. 15 and 16, the position of the ball 16 may be regulated using a retainer 18 serving as a regulating member. That is, as shown in FIG. 16, a plurality of ball receiving portions 18a are connected to the connecting portions 18a.
b, and furthermore, a retaining portion 18c is protruded to form the retainer 18. As shown in FIG. 15, the ball 16 is mounted on the ball receiving portion 18a of the retainer 18, and the engaging portion 18c is elastically deformed on the engaging portion 7a5 formed of a ring groove provided on the shaft portion 7a1 of the flange gear 7a. And the retainer 18 on which the ball 16 is mounted is rotatably engaged with the shaft portion 7a1. After that, the holder 15 is attached to the shaft portion 7a1.

The position of the ball 16 in the direction of the rotation axis of the photosensitive drum 7 is regulated by the retainer 18.
Is regulated by the retainer 18 to be constant.

If the retainer 18 is used as described above, the ball 1 as a rolling element can be obtained simply by providing the locking portion 7a5 on the shaft portion 7a1.
6 can be mounted, and the rotational torque when the photosensitive drum 7 is driven can be reduced.

[Eleventh Embodiment] The embodiment shown in FIG. 17 has substantially the same structure as the tenth embodiment, and the retainer 18 shown in the tenth embodiment is engaged with the holder 15.
That is, the ball 16 is mounted on the retainer 18 having the engaging portion 18c formed outward, and the ball 16 is locked on the locking portion 15d formed of a ring groove formed on the inner diameter portion of the holder 15, and this is connected to the shaft of the flange gear 7a. It is assembled to the part 7a1.

As described above, even when the retainer 18 is locked to the holder 15, the same effect as in the tenth embodiment can be obtained.

[Twelfth Embodiment] The embodiment shown in FIG.
An intake hole 17b is formed in the drum positioning shaft 17 having the structure shown in the above-described seventh embodiment (see FIG. 11), and this is communicated with the concave portion 17a. When assembling the ball 16 as a rolling element, a suction tool 19 is attached to the end of the suction hole 17b opposite to the concave portion 17a to perform suction.
When the ball 6 is fitted into the concave portion 17a, the ball 16 is attracted to the concave portion 17a. Therefore, even if the photosensitive drum 7 is installed in a horizontal state, the ball 16 does not fall out of the concave portion 17a, and the assembling can be easily performed. Although not shown, when the mounting recess of the ball 16 is on the holder side as shown in the fifth embodiment (see FIG. 8) and the sixth embodiment (see FIG. 10), And the suction hole is suctioned by a suction tool, so that the sphere 16 is sucked into the concave portion provided in the holder 15 so that the mounting can be performed in the same manner as described above.

[Thirteenth Embodiment] In the above-described embodiment, the ball 16 is mounted in the recess. However, FIG.
As shown in FIG. 7, a cylindrical roller 20 is used in place of the ball 16, and a concave portion 7a6 in which the roller 20 can be mounted is formed on the shaft portion 7.
It is provided at the outer diameter part of a1 or the inner diameter part of the holder 15. The position of the roller 20 is regulated by the concave portion 7a6, and the roller 20 is interposed between the rotating body and the holding member.
The rotating torque of the rotating body may be reduced.

[Other Embodiments] In the above-described embodiment,
The photosensitive drum 7 or the developing sleeve 10c which is a rotating body
A ball or roller as a rolling element is brought into contact with the roller.
However, the present invention is not limited to this. The sphere or roller is made of metal, conductive plastic, or conductive elastomer, and the holder 15, which is a holding member, is also made of a conductive material. May be contacted. This makes it easy to ground the photosensitive drum 7 and to apply a voltage to the developing sleeve 10c.

On the other hand, the ball or roller as the rolling element may be made of an elastomer such as plastic, nylon, polyacetal, or hard rubber. In this case, it is possible to absorb the impact of the rotating body in the direction of the rotating radius when the rotating body is driven. Occurrence of a gap can be eliminated due to variation in dimensions.

In the above-described embodiment, an example is shown in which balls or rollers, which are rolling elements, are provided only on the side where the flange gear is provided. However, this is because the driving force is transmitted via the flange gear. This is because a large force is applied to the holding member on the driving side of the body. However, if this rolling element is provided on both the driving side and the non-driving side, the effect of reducing the rotational torque is further increased. Is raised.

Further, in the above-described embodiment, the photosensitive drum 7 or the developing sleeve 10c has been described as an example of the rotating body. However, the present invention is not limited to this. Any other rotating body can be applied. Further, it may be used for a plurality of rotating members such as a photosensitive drum and a developing sleeve.

In the above-described embodiment, the holder 15 is exemplified as the holding member for holding the rotating body. However, the rotating body may be directly held by the cartridge frame itself.

Further, the process cartridge B according to the present invention is not limited to the case where a single color image is formed as described above, but is also provided with a plurality of developing means, and a plurality of color images (for example,
The present invention can be suitably applied to a cartridge for forming a color image, a three-color image, or a full-color image.

The image carrier is not limited to the photosensitive drum, and includes, for example, the following. First, a photoconductor is used as a photoconductor, and examples of the photoconductor include amorphous silicon, amorphous selenium, zinc oxide, titanium oxide, and an organic photoconductor (OPC). The shape on which the photoconductor is mounted includes, for example, a rotating body such as a drum or a belt, and a sheet. In general, a drum-shaped or belt-shaped one is used.For example, in the case of a drum-type photoconductor, a photoconductor is deposited or coated on a cylinder of an aluminum alloy or the like. is there.

As a developing method, it is possible to use various developing methods such as a known two-component magnetic brush developing method, a cascade developing method, a touch-down developing method, and a cloud developing method.

As for the structure of the charging means, the so-called contact charging method is used in the first embodiment. However, as another structure, a metal shield such as aluminum is provided around three sides of a conventionally used tungsten wire. It is a matter of course that a configuration may be used in which positive or negative ions generated by applying a high voltage to the tungsten wire are moved to the surface of the photosensitive drum, and the surface of the drum is uniformly charged.

The charging means may be of a blade type (charging blade), a pad type, a block type, a rod type, a wire type, or the like, in addition to the roller type.

As a method for cleaning the toner remaining on the photosensitive drum, the cleaning means may be constituted by using a blade, a fur brush, a magnetic brush or the like.

The process cartridge described above is
It is provided with, for example, an electrophotographic photosensitive member as an image carrier, and at least one of processing means. Therefore, as a mode of the process cartridge, in addition to the above-described embodiment, for example, the image carrier and the charging unit are integrally formed into a cartridge and can be attached to and detached from the apparatus main body. A device in which the image carrier and the developing means are integrally formed into a cartridge and can be attached to and detached from the apparatus main body. A device in which the image carrier and the cleaning means are integrally formed into a cartridge and can be attached to and detached from the apparatus main body. Further, there is a type in which an image carrier and two or more of the above-mentioned process means are combined into a cartridge to be detachable from the apparatus main body.

That is, the above-mentioned process cartridge is a cartridge in which a charging unit, a developing unit or a cleaning unit and an electrophotographic photosensitive member are integrally formed into a cartridge, and this cartridge is detachably mountable to an image forming apparatus main body. . In addition, at least one of the charging unit, the developing unit, and the cleaning unit and the electrophotographic photosensitive member are integrally formed into a cartridge so that the cartridge can be attached to and detached from the image forming apparatus main body. Further, it means that at least the developing means and the electrophotographic photosensitive member are integrally formed into a cartridge so as to be detachable from the apparatus main body.

In the above-described embodiment, the photosensitive drum 7 and the developing sleeve 10c are formed into cartridges, and an apparatus for forming an image by mounting the process cartridge is illustrated. However, the photosensitive drum 7 and the developing sleeve 10c are formed into cartridges. The present invention can be similarly applied to an image forming apparatus directly attached to the apparatus main body without performing.

Further, in the above-described embodiment, a laser beam printer is exemplified as an image forming apparatus. However, the present invention is not limited to this. For example, an electrophotographic copying machine, a facsimile apparatus, or another image forming apparatus such as a word processor. Of course, it is also possible to use.

In each of the above-described embodiments, the rotation of the rolling element causes rolling resistance between the rotating body and the holding member, thereby reducing the torque of the process cartridge and reducing the load fluctuation. Therefore, the rotating body can be rotated with a small rotating torque, and the drive source such as a motor and the drive transmission system such as a gear can be reduced in size and cost. Further, it is possible to reduce the rotation unevenness of the rotating body due to the reduction of the load fluctuation and the density unevenness caused by the rotation unevenness.

Further, by regulating the position of the rolling element by the rotating element or the holding member, the bearing can be provided at a low cost without increasing the size of the bearing portion.

Further, when plastics or elastomers are used as the rolling elements, it is possible to absorb shocks and vibrations at the time of driving the rotating bodies, and it is possible to absorb density unevenness on an image due to the shocks and vibrations applied to the rotating bodies. Can be reduced.

[0088]

As described above, according to the present invention, the rotating load of the rotating body can be reduced, and the rotating body can be rotated with a small torque.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a configuration of an image forming apparatus according to the present invention.

FIG. 2A is an explanatory diagram of a configuration of a process cartridge according to the present invention. FIG. 2B is an external perspective view of the process cartridge according to the present invention.

FIG. 3 is an explanatory diagram of a bearing configuration of a developing sleeve according to the first embodiment.

FIG. 4 is an explanatory view of a second embodiment using rollers as rolling elements.

FIG. 5 is an explanatory view of a third embodiment in which a dowel is used as a holding member of a rotating body.

FIG. 6 is an explanatory diagram of a fourth embodiment showing a bearing configuration of a photosensitive drum.

FIG. 7A is a side view illustrating a bearing configuration of the photosensitive drum, and FIG. 7B is a perspective view illustrating a shaft of the photosensitive drum.

FIG. 8 is a configuration explanatory view of a fifth embodiment in which the position of a rolling element is regulated by a holder as a holding member.

FIG. 9 is an explanatory perspective view of a fifth embodiment.

FIG. 10 shows a state in which the photosensitive drum is held by a positioning shaft,
It is an explanatory view of a sixth embodiment in which a concave portion is provided in the flange gear.

FIG. 11 shows a state in which the photosensitive drum is held by a positioning shaft.
It is an explanatory view of a seventh embodiment in which a concave portion is provided in the shaft.

FIG. 12 is an explanatory view of an eighth embodiment in which a concave portion is provided in a shaft portion of a photosensitive drum, and the position of a sphere is regulated by a step portion provided in the drum shaft portion and a holder.

FIG. 13 is an explanatory perspective view of an eighth embodiment.

FIG. 14 shows a ninth embodiment in which a concave portion is provided in the photoconductor holder, and the position of the sphere is regulated by a step provided in the drum shaft portion and the holder.
It is explanatory drawing of an Example.

FIG. 15 is a configuration explanatory view of a tenth embodiment in which the position of a rolling element is regulated using a retainer.

FIG. 16 is an explanatory perspective view of a retainer.

FIG. 17 is an explanatory view of an eleventh embodiment for locking a retainer to a holder.

FIG. 18 is an explanatory view of a twelfth embodiment in which a suction hole is provided to assemble a rolling element by suction.

FIG. 19 is an explanatory view of a thirteenth embodiment in which rollers are used as rolling elements.

[Explanation of symbols]

 Reference Signs List A Image forming apparatus B Process cartridge 1 Optical system 1a Optical unit 1b Laser diode 1c Polygon mirror 1d Scanner motor 1e Imaging lens 1f Reflection mirror 2 Recording medium 3 Transport means 3a Cassette 3b Pickup roller 3c1, 3c2 Registration roller 3d Transport roller 3e Guide Plate 3f Discharge Roller 4 Transfer Means 5 Fixing Means 5a Drive Roller 5b Heater 5c Fixing Roller 6 Discharge Section 7 Photoconductor Drum 7a Drum Flange Gear 7a1 Shaft 7a2 Concave 7a3 Concave 7a4 Step 7a5 Locking Section 7a6 Concave Roller 8 Charging Shaft 9 Exposure unit 10 Developing means 10a Toner feed member 10b Magnet 10c Developing sleeve 10d Developing blade 10e Sleeve gear 10f End flange 10g Sleeve cap 10h Groove 10i Ball 10j Roller 10k Roller holding portion 11 Cleaning means 11a Cleaning blade 11b Squeeze sheet 11c Waste toner reservoir 12 Housing 12a Toner frame 12b Cleaning frame 13 Device body 14 Opening / closing cover 14a Hinge 15 Holder 15a Depression 15b Step 15c Stop portion 16 Ball 17 Positioning shaft 17a Recess 17b Intake hole 18 Retainer 18a Ball receiving portion 18b Connecting portion 18c Engagement portion 19 Suction tool 20 Cylindrical roller

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Isao Ikemoto 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Shigeo Miyabe 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon (56) References JP-A-4-168948 (JP, A) JP-A-63-274340 (JP, A) JP-A-2-138770 (JP, U) JP-A-5-15068 (JP, A) U) JitsuHiraku flat 2-17491 (JP, U) (58 ) investigated the field (Int.Cl. ^7, DB name) G03G 21/18

Claims (2)

(57) [Claims] 1. A method for attaching a rolling element to a process cartridge mountable to an image forming apparatus main body, comprising: a rotatable rotating element; and a support member for supporting the rotating element. In order to smoothly rotate the rotating body, the rolling body is directly incorporated rotatably between the cylindrical member and the support member, and the rotation that regulates the position of the rolling body in the axial direction and the rotating direction of the rotating body. Suctioning the rolling element from a suction hole provided at the rolling element regulating position of the body to the rolling element at the rolling element regulating position of the rotating body, and assembling the holding member to the rotating body in this state. How to attach the moving body. 2. A method for attaching a rolling element to a process cartridge mountable to a main body of an image forming apparatus, comprising: a rotatable rotating element; and a support member for supporting the rotating element. When the rolling element is directly rotatably assembled between the cylindrical member and the support member in order to smooth the rotation of the rotating element, the position of the rolling element in the axial direction and the rotation direction of the rotating element is held. The rolling element is sucked into the rolling element regulating position of the holding member by sucking through an intake hole provided at the rolling element regulating position of the member, and the rotating body is assembled to the holding member in that state. How to attach the moving body.