HK1240329B - Drum cylinder unit, method for attaching coupling member, and drum unit - Google Patents

Description

Drum unit, method of attaching coupling member, and drum unit

Technical Field

The present invention relates to a drum unit and a drum unit for use in an electrophotographic image forming apparatus such as a laser beam printer. The present invention also relates to a method of attaching a coupling member.

Background Art

Regarding an electrophotographic imaging device, a configuration has been proposed in which a photosensitive drum and a developing roller, etc., which are rotating components involved in imaging, are integrated into a cartridge that is attachable to and removable from a main body of the imaging device (hereinafter referred to as the "device main body"). In order to rotate the photosensitive drum in the cartridge, a driving force is ideally transmitted from the device main body to the photosensitive drum. A configuration has been proposed in which a cartridge-side coupling member engages with a device-main body-side driving force transmission unit (e.g., a drive pin) to transmit the driving force.

In some imaging devices, the cartridge can be removed in a predetermined direction that is substantially perpendicular to the rotation axis of the photosensitive drum. A device body is proposed that does not have a mechanism for moving a drive pin of the device body in the direction of the rotation axis by opening and closing a cover of the device body. Specifically, PTL 1 and PTL 2 disclose a structure in which a coupling member provided at the end of the photosensitive drum is capable of tilting relative to the rotation axis of the photosensitive drum. The coupling member provided in the cartridge engages with a drive pin provided in the device body, so that a driving force is transmitted from the device body to the cartridge.

Reference List

Patent Literature

PTL1: Japanese Patent Laid-Open No. 2008-233867

PTL2: Japanese Patent Laid-Open No. 2014-112169

Summary of the Invention

Solution to the problem

The present invention develops the above-mentioned prior art and facilitates attaching a coupling member provided at an end portion of a photosensitive drum to the photosensitive drum.

According to one aspect of the present invention, a drum unit used in an electronic photographic imaging device includes a photosensitive drum and a flange member, wherein the flange member includes a fixed portion fixed to the end of the photosensitive drum, a cylindrical portion in which a hollow portion is formed, a groove portion arranged at the edge of the cylindrical portion, and a gear portion, and wherein the groove portion and the hollow portion lead to the outside in the axial direction of the photosensitive drum.

Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a cross-sectional view of the device body and the cartridge;

FIG2 is a cross-sectional view of the box;

FIG3 is an exploded perspective view of the cartridge;

4A is an explanatory diagram showing the cartridge being attached to and removed from the apparatus main body;

4B is an explanatory diagram showing the cartridge being attached to and removed from the apparatus main body;

5A1 is an explanatory diagram showing the cartridge being attached to and removed from the apparatus main body while tilting the coupling member;

5B1 is a sectional view showing the cartridge being attached to and removed from the apparatus main body while tilting the coupling member;

5A2 is an explanatory diagram showing the cartridge being attached to and removed from the apparatus main body while tilting the coupling member;

5B2 is a sectional view showing the cartridge being attached to and removed from the apparatus main body while tilting the coupling member;

5A3 is an explanatory diagram showing the cartridge being attached to and removed from the apparatus main body while tilting the coupling member;

5B3 is a sectional view showing the cartridge being attached to and removed from the apparatus main body while tilting the coupling member;

5A4 is an explanatory diagram showing the cartridge being attached to and removed from the apparatus main body while tilting the coupling member;

5B4 is a sectional view showing the cartridge being attached to and removed from the apparatus main body while tilting the coupling member;

FIG6A is an explanatory diagram of a drum unit;

FIG6B is an explanatory diagram of the drum unit;

FIG7A is an explanatory diagram of a coupling member and a pin;

FIG7B is a cross-sectional view of the coupling member and the pin;

FIG7C is an explanatory diagram of a coupling member and a pin;

FIG8A is an explanatory diagram of the structure of the drum unit;

FIG8B is an explanatory diagram of the structure of the drum unit;

FIG8C is an explanatory diagram of the structure of the drum unit;

FIG9A is an explanatory diagram of a driving side flange;

FIG9B is an explanatory diagram of the driving side flange;

FIG9C is a cross-sectional view of the drive side flange;

FIG9D is a cross-sectional view of the drive side flange;

FIG9E is an enlarged view of the drive side flange;

FIG10A is an explanatory diagram showing the assembly of a coupling member and a pin to the drum unit;

10B is an explanatory diagram showing the assembly of the coupling member and the pin to the drum unit;

10C is a cross-sectional view showing the assembly of the coupling member and the pin to the drum unit;

FIG11A is an explanatory diagram of the drum unit;

FIG11B is a sectional view of the drum unit;

FIG11C is a sectional view of the drum unit;

FIG12 is an exploded perspective view of the cleaning unit;

FIG13A is an explanatory diagram of the cantilever portion of the drive side flange;

FIG13B is an explanatory diagram of the cantilever portion of the drive side flange;

FIG13C is a cross-sectional view of the cantilever portion of the drive side flange;

FIG14A is an explanatory diagram of a driving side flange and a cover member;

FIG14B is an explanatory diagram of the driving side flange and the cover member;

Fig. 14C is a sectional view of the driving side flange and the cover member;

FIG15A is an explanatory perspective view of the drum unit;

FIG15B is an enlarged view of the drum unit;

Fig. 16A is an explanatory perspective view of a drum unit;

FIG16B is an enlarged view of the drum unit;

FIG17A is an illustrative perspective view of a method for securing a drive side flange and a pin;

FIG17B is an illustrative perspective view of a method for securing the drive side flange and pin;

FIG17C is an illustrative perspective view of a method for securing the drive side flange and pin;

FIG17D is an illustrative perspective view of a method for securing the drive side flange and pin;

FIG18A is an explanatory diagram of a pin stop structure;

FIG18B is an explanatory diagram of a pin stop structure;

FIG18C is an explanatory diagram of a pin retaining structure;

FIG19A is an explanatory diagram of the driving side flange and the upper cover member;

FIG19B is an explanatory diagram of the driving side flange and the upper cover member;

FIG20A is an explanatory diagram showing the assembly of the drum unit;

FIG20B is an explanatory diagram showing the assembly of the drum unit;

FIG20C is an explanatory diagram showing the assembly of the drum unit;

FIG21 is an explanatory diagram of the drive side flange and the pin;

FIG22 is an explanatory diagram of the driving side flange.

DETAILED DESCRIPTION

Embodiments to which the present invention is applied are described below with reference to the accompanying drawings.

Imaging devices that utilize electrophotography are referred to herein as electrophotographic imaging devices. Electrophotography is a method of developing an electrostatic image formed on a photoconductor using toner. Any development system can be employed, including single-component development systems, two-component development systems, and dry development systems. An electrophotographic photosensitive drum, herein, has a photoconductor on the surface layer of a drum-shaped cylindrical body used in an electrophotographic imaging device.

Here, the charging roller and developing roller, etc., which are related to image formation and act on the photosensitive drum, are referred to as process components. A cartridge provided with a photoconductor or process components (e.g., a cleaning blade and developing roller) related to image formation is referred to as a process cartridge. In the embodiments, a process cartridge in which a photosensitive drum, a charging roller, a developing roller, and a cleaning blade are integrated is described as an example.

In the embodiments, a laser beam printer is described as an exemplary electrophotographic imaging device to be used in various applications, such as multifunction peripherals, facsimile machines, and printers. Reference numerals in the embodiments are provided for reference purposes only and are not intended to limit the configuration. Dimensions in the embodiments are shown for clarity of description and do not limit the configuration.

The longitudinal direction of the process cartridge in the embodiment refers to a direction that intersects substantially perpendicularly with the direction in which the process cartridge is attached to the main body of the electrophotographic imaging device and is removed from the main body. The longitudinal direction of the process cartridge is parallel to the axis of rotation of the electrophotographic photosensitive drum (this direction intersects with the sheet conveying direction). In the longitudinal direction, the side of the process cartridge on which the photosensitive drum receives the rotational force from the imaging device main body is defined as the drive side (driven side), and the opposite side thereof is defined as the non-drive side. Unless expressly specified, the term "above" (upper) indicates the upper side in the direction of gravity when the imaging device is installed, and the opposite direction is defined as "below" (lower) in the direction of gravity.

[First embodiment]

The laser beam printer in this embodiment is described below with reference to the accompanying drawings. The cartridge in this embodiment is a process cartridge in which a photosensitive drum as a photoconductor (image bearing member or rotating member), a developing roller as a processing device, a charging roller, and a cleaning blade are integrated. The cartridge can be attached to and removed from the device main body. The cartridge has a gear, a photosensitive drum, a flange, a developing roller, etc. as a rotating member/rotating member, and the rotating member/rotating member rotates when receiving a rotational force from the device main body.

Among the rotating members/rotating members, a member that bears and conveys a toner image is referred to as an image bearing member.

The configuration and image forming process of a laser beam printer as an electrophotographic image forming apparatus will be described below with reference to Fig. 1. The detailed configuration of the process cartridge will then be described with reference to Figs.

(Laser Beam Printers and Imaging Processing)

1 is a sectional view of a laser beam printer apparatus body A (hereinafter "apparatus body A") and a process cartridge (hereinafter "cartridge B"), the apparatus body A being an electrophotographic image forming apparatus.

The apparatus main body A is referred to herein as a laser beam printer, which is an electrophotographic image forming apparatus from which the detachable cartridge B has been removed.

First, the configuration of a laser beam printer, which is an electrophotographic image forming apparatus, will be described with reference to FIG. 1 .

The electrophotographic image forming apparatus shown in FIG1 is an electrophotographic laser beam printer in which a cartridge B can be attached to and removed from an apparatus main body A. When the cartridge B is attached to the apparatus main body A, the cartridge B is arranged below a laser scanning unit 3 as an exposure unit (exposure device).

A sheet tray 4 for accommodating sheets P (sheet material) as recording media, which are targets (objects) for image formation by the image forming apparatus, is arranged below the cartridge B.

In the apparatus body A, a pickup roller 5a, a supply roller pair 5b, a conveying roller pair 5c, a transfer guide 6, a transfer roller 7, a conveying guide 8, a fixing device 9, a discharge roller pair 10, and a discharge tray 11 are arranged in this order from upstream along the conveying direction X1 of the sheet P. The fixing device 9 as a fixing means is constituted by a heating roller 9a and a pressure roller 9b.

Next, the imaging process is schematically described with reference to FIG. 1 and FIG. 2 .

According to a print start signal, the drum 62 as a rotatable photosensitive drum on which the developer is carried is driven to rotate in the direction of arrow R (hereinafter referred to as “rotation direction” R) at a predetermined circumferential speed (process speed).

The drum 62 is a drum-shaped (cylindrical) electrophotographic photoconductor (photosensitive drum) in which a photoconductive layer is formed on the surface of the drum.

The charging roller 66 to which a bias voltage is applied is in contact with the outer peripheral surface of the drum 62 so as to uniformly charge the outer peripheral surface of the drum 62 .

The laser scanning unit 3 as an exposure unit outputs laser light L according to image information input into the laser beam printer. The laser light L passes through the exposure window 74 on the upper surface of the cartridge B and scans and exposes the outer peripheral surface of the drum 62. The drum 62 is thereby partially charged and an electrostatic image (electrostatic latent image) is formed on the surface of the photosensitive drum.

2 , in the developing unit 20 as the developing device, the developer (hereinafter referred to as “toner T”) in the toner chamber 29 is agitated and conveyed by the rotation of the conveying screw 43 as the conveying member and sent out to the toner supply chamber 28 .

The toner T, which serves as a developer, is carried on the surface of the developing roller 32, which serves as a developing unit (a processing device and a rotating member), by the magnetic force of the magnetic roller 34 (a fixed magnet). The developing roller 32 serves as a rotating member that carries the developer and transports the developer to a development area to develop the electrostatic image formed on the drum 62. The thickness of the toner T layer transported to the development area on the outer peripheral surface of the developing roller 32 is regulated by the developing blade 42. The toner T is charged by friction between the developing roller 32 and the developing blade 42.

The toner T carried by the developing roller 32 develops (visualizes) the electrostatic image formed on the drum 62. The drum 62 rotates in a rotational direction R, and the toner (toner image, developer image) is developed on the drum surface. Specifically, the drum (photosensitive drum) 62 is an image-bearing member that carries the image (toner image). The developing roller 32 is a developer carrier that carries the developer (toner) and develops the latent image formed on the drum 62.

As shown in FIG. 1 , in accordance with the output timing of the laser light L, the pickup roller 5 a , the feed roller pair 5 b , and the conveyance roller pair 5 c feed the sheet P accommodated in the lower portion of the apparatus body A from the sheet tray 4 .

The sheet P is supplied to a transfer position (transfer nip) between the drum 62 and the transfer roller 7 via the transfer guide 6. At the transfer position, the toner image is sequentially transferred from the drum 62 as an image bearing member to the sheet P as a recording medium.

The sheet P to which the toner image has been transferred is separated from the drum 62 and conveyed along the conveying guide 8 to the fixing device 9. The sheet P passes through the fixing nip of the heating roller 9a and the pressure roller 9b, which constitute the fixing device 9. At the fixing nip, the unfixed toner image on the sheet P is fixed to the sheet P by pressure and heat. The sheet P to which the toner image has been fixed is then conveyed by the discharge roller pair 10 and discharged to the discharge tray 11.

As shown in FIG2 , after the toner T is transferred to the sheet, the residual toner remaining on the drum surface that has not been transferred to the sheet adheres to the surface of the drum 62. The residual toner is removed by a cleaning blade 77 that contacts the outer peripheral surface of the drum 62. Then, the toner remaining on the drum 62 is cleaned and the cleaned drum 62 is charged again for the image forming process. The toner removed from the drum 62 (residual toner) is stored in the waste toner chamber 29 of the cleaning unit 60.

In the above description, the charging roller 66, the developing roller 32, and the cleaning blade 77 serve as the processing means acting on the drum 62. Although the image forming apparatus of this embodiment adopts a method in which the residual toner is removed by the cleaning blade 77, a method (no-cleaning means method) in which the residual toner whose charge is adjusted is collected simultaneously with development in the developing device may also be adopted. In the no-cleaning means method, an auxiliary charging member (e.g., an auxiliary charging brush) for adjusting the charge of the residual toner also serves as the processing means.

(Structure of Process Cartridge)

Next, the detailed configuration of the cartridge B will be described with reference to FIG. 2 and FIG. 3 .

Fig. 3 is the exploded perspective view of box B. The framework of box B can be decomposed into multiple units.The box B of the present embodiment is made of two units (that is, cleaning unit 60 and developing unit 20) that are integrated with each other. Although developing unit 20 and the cleaning unit 60 that keeps drum 62 utilize two connecting pins 75 to link to each other in the present embodiment, three or more units can be integrated. Alternatively, multiple units that are not connected by coupling member (for example pin) can be used so that some units in the described multiple units can be replaced.

The cleaning unit 60 is composed of a cleaning frame 71 , a drum unit U1 , a charging roller 66 , a cleaning blade 77 , and the like.

The drum unit U1 is composed of a drum unit U2, a coupling member 86 provided at the drive side end of the drum unit U2, and a pin 88 (see Figures 6A and 6B). The drum unit U2 is composed of a drum 62, a drive side flange 87 (details of which will be described below) as a flange member attached to the drive side of the drum 62, and the like.

The rotational force from the apparatus body A is transmitted to the drum 62 via the driving-side flange 87 and the coupling member 86 .

As shown in Figure 3, the drum 62 is rotatable about a rotation axis L1 (hereinafter referred to as "axis L1"). The coupling member 86 is rotatable about a rotation axis L2 (hereinafter referred to as "axis L2"). The coupling member 86 is tiltable (skewed) relative to the drum 62. In other words, the inclination angle of the coupling member 86 relative to the drive-side flange 87 or the drum 62 is variable. Therefore, the axis L2 is tiltable (variable) relative to the axis L1. Details will be described later.

As shown in Figures 2 and 3, the developing unit 20 is composed of a toner storage container 22, a bottom material 21, a first side member 26L (non-driving side), a second side member 26R (driving side), a developing blade 42, a developing roller 32, and a magnetic roller 34. A conveying screw 43 (a stirring blade) as a conveying member for conveying the toner and a toner T as a developer are provided in the toner container 22. The developing unit 20 has a compression spring 46 between the developing unit 20 and the cleaning unit 60, and the compression spring 46 applies an urging force to regulate the orientation of the developing unit 20. The cleaning unit 60 and the developing unit 20 are pivotally connected by a connecting pin 75 as a connecting member and are configured as a cartridge B.

Specifically, pivot holes 23bL and 23bR are provided at the ends of arm portions 23aL and 23aR provided at both ends of the developing unit 20 in the longitudinal direction (the axial direction of the developing roller 32). The pivot holes 23bL and 23bR are provided in parallel with the axis of the developing roller 32.

An insertion hole 71a into which a connecting pin 75 is inserted is provided at each of both end portions in the longitudinal direction of a cleaning frame 71, which is a side frame of the cleaning unit 60. The connecting pin 75 is inserted into the pivot holes 23bL and 23bR and the insertion hole 71a, with the arm portions 23aL and 23aR aligned with predetermined positions of the cleaning frame 71. Then, the cleaning unit 60 and the developing unit 20 are pivotally combined around the connecting pin 75 as a connecting member.

The compression spring 46 attached to each of the bases of the arm portions 23 aL and 23 aR contacts the cleaning frame 71 and pushes the developing unit 20 against the cleaning unit 60 about the connecting pin 75 as a pivot.

In this way, the developing roller 32 as the processing device is reliably pressed in the direction of the drum 62 as the rotating member. A spacer (not shown) as an annular spacing member attached to each of the two end portions of the developing roller 32 keeps the developing roller 32 at a predetermined distance from the drum 62.

(Attachment and Removal of Process Cartridge)

Attachment and removal of the cartridge B to and from the apparatus main body A in the above-described configuration will be described with reference to FIG. 4A to FIG. 5B4 .

Fig. 4A and 4B are explanatory diagrams showing that box B is attached to apparatus body A and removed from apparatus body A. Fig. 4A is a perspective view observed from the non-driving side, and Fig. 4B is a perspective view observed from the driving side. The driving side refers to an end of the coupling member 86 provided with box B in the longitudinal direction.

The door 13 is pivotally attached to the apparatus main body A. 4A and 4B show the apparatus main body A in a state in which the door 13 is open.

The drive head 14 and the guide member 12 as a guide mechanism are arranged inside the device body A. The drive head 14 arranged on the device body A side is a main body side transmission mechanism that transmits the driving force to the box B attached to the device body A, and is engaged with the coupling member 86 of the box B. After the engagement, the rotational force can be transmitted to the box B when the drive head 14 rotates. The drive head 14 is rotatably supported by the device body A. The drive head 14 has a drive pin 14b as an applying portion that applies the rotational force (see Figure 5B3).

The guide member 12 as a guide mechanism is a main body side guide member that guides the cartridge B into the apparatus main body A. The guide member 12 may be a plate-like member having a guide groove or may be a member that guides the cartridge B while supporting it from below.

A state in which the box B is attached to and removed from the device body A while tilting (tilting, shaking or rotating) the coupling member 86 as the driving force transmission part is described below with reference to Figures 5A1 to 5B4.

Figure 5A1 to Figure 5B4 is to attach box B to device body A and remove box B from device body A when making coupling member 86 tilt (skew, shake or rotate).Figure 5A1 to Figure 5A4 is the enlarged view of the coupling member 86 vicinity area observed from the drive side to the non-drive side.Figure 5B1 is the cross-sectional view (VB1 cross-sectional view) taken along the line BV1-VB1 of Figure 5A1.Similarly, Figure 5B2 is the cross-sectional view (VB2 cross-sectional view) taken along the line VB2-VB2 of Figure 5A2, Figure 5B3 is the cross-sectional view (VB3 cross-sectional view) taken along the line VB3-VB3 of Figure 5A3, and Figure 5B4 is the cross-sectional view (VB4 cross-sectional view) taken along the line VB4-VB4 of Figure 5A4.

5A1 to 5A4 illustrate a process of attaching the cartridge B to the apparatus main body A. FIG5A4 illustrates a state in which the attachment of the cartridge B to the apparatus main body A is completed. In FIG5A1 to FIG5A4, the guide member 12 and the drive head 14 are illustrated as components of the apparatus main body A, and the other components are illustrated as components of the cartridge B.

The directions shown by the arrows X2 and X3 in Figures 5A1 to 5B4 are substantially perpendicular to the rotation axis L3 of the drive head 14. The direction represented by the arrow X2 is called the X2 direction and the direction represented by the arrow X3 is called the X3 direction. Similarly, the X2 and X3 directions are substantially perpendicular to the axis L1 of the drum 62 of the process cartridge. In Figures 5A1 to 5B4, the direction represented by the arrow X2 is the direction along which cartridge B is attached to the device body A. The direction represented by the arrow X3 is the direction along which cartridge B is removed from the device body. The directions represented by the arrows X2 and X3 can be collectively referred to as attachment/removal directions. It should also be understood that attachment and removal have directional meanings. In this case, phrases such as "upstream in the attachment direction," "downstream in the attachment direction," "upstream in the removal direction," "downstream in the removal direction," etc. can be used.

As shown in Figure 5A1 to Figure 5B4, box B has a spring as a pushing member (elastic member). In the present embodiment, a torsion spring 91 is used as a spring. The torsion spring 91 pushes the free end portion 86a of the coupling member 86 so that it falls towards the drive head 14. That is, in the attachment process of box B, the torsion spring 91 pushes the coupling member 86 so that the free end portion 86a faces the downstream in the attachment direction. Box B is inserted in the device body A, and wherein the free end portion 86a of the coupling member 86 faces the drive head 14.

Here, the rotation axis of the drum 62 is defined as axis L1, the rotation axis of the coupling member 86 is defined as axis L2, and the rotation axis of the drive head 14 as the main body side engaging portion is defined as axis L3. Then, as shown in Figures 5B1 to 5B3, axis L2 is inclined relative to axes L1 and L3.

When the cartridge B is inserted to the extent shown in Figures 5A3 and 5B3, the coupling member 86 contacts the drive head 14. Figure 5B3 shows an example in which the drive pin 14b, which serves as the applying portion, contacts the standby portion 86k1 of the coupling member, which applies a rotational force. This contact regulates the position (skew) of the coupling member 86 and gradually reduces the amount of inclination (skew) of the axis L2 relative to the axis L1 (axis L3).

In this embodiment, the drive pin 14b, which serves as the application portion, contacts the standby portion 86k1 of the coupling member. However, the contact position between the coupling member 86 and the drive head 14 varies depending on the phase relationship between the coupling member 86 and the drive head 14 in the rotational direction. Therefore, the contact position of this embodiment is not restrictive. It is only necessary that any portion of the free end portion 86a of the coupling member contacts any portion of the drive head 14.

5A4 and 5B4, axis L2 is located on substantially the same line as axis L1 (axis L3). That is, the rotation axes of coupling member 86, drive head 14 and drum 62 are located on substantially the same line.

Therefore, when the coupling member 86 that is arranged in box B engages with the drive head 14 that is arranged in device main body A, rotational force can be transmitted to box B from device main body A.When box B will be removed from device main body A, state is converted into the state shown in Figures 5A1 and 5B1 from the state shown in Figures 5A4 and 5B4.When coupling member 86 tilts (skews) relative to axis L1 in the same manner as the attachment operation, coupling member 86 separates from drive head 14. That is, box B moves along the X3 direction (substantially perpendicular to the rotation axis L3 of drive head 14) opposite to the X2 direction, and coupling member 86 separates from drive head 14.

Box B only moves along the X2 direction or the X3 direction in the area near the attachment completion position. Box B can move along any direction in the position except the area near the attachment completion position. That is, it is only necessary to make the moving track of box B move along the predetermined direction of the rotation axis L3 that is substantially perpendicular to and intersects the drive head 14 when coupling member 86 is just about to engage with the drive head 14 or coupling member 86 is just about to be removed from the drive head 14.

(Drum Unit)

6A and 6B , the drum unit U1 included in the cleaning unit 60 (see FIG3 ) is described. FIG6A and 6B are explanatory diagrams of the drum unit U1. FIG6A is an exploded perspective view and FIG6B is a perspective view. As shown in FIG6A and 6B , the drum unit U1 is constructed by attaching a coupling member 86 and a pin 88 to the drum unit U2. Each part constituting the drum unit U1 and the assembly method are described in detail below.

(Connecting member and pin)

First, the coupling member 86 and the pin 88 are described with reference to FIG. 7A to FIG. 7C .

7A to 7C are explanatory diagrams of the coupling member 86 and the pin 88. FIG7A is an explanatory side view of the coupling member 86 viewed in a direction perpendicular to the axis L2, with the drive head 14 attached thereto. FIG7B is a cross-sectional view taken along line VIIB-VIIB of FIG7A . FIG7C is a perspective view.

As shown in FIG7A , the coupling member 86 mainly has three parts. The first part is the free end portion 86 a, which engages with the drive head 14 and receives the rotational force from the drive head 14 (its drive pin 14 b). The second part is the connecting portion 86 c, which is substantially spherical and is accommodated in the hollow portion 87 e (details of which will be described later) of the drive-side flange 87. The third part is the connecting portion 86 b, which connects the free end portion 86 a and the connecting portion 86 c.

The free end portion 86 a has two protruding portions ( 86 a 1 and 86 a 2 ) that come into contact with the drive pin 14 b of the drive head 14 so as to receive the rotational force of the drive head 14 .

The connecting portion 86c has a substantially spherical spherical surface 86e and a through hole portion 86d passing through the spherical surface 86e. The connecting portion 86c (its spherical center 86f) becomes the tilt center of the coupling member 86 when the coupling member 86 is accommodated in the driving side flange 87.

As shown in Figure 7B, the pin 88 as a cylindrical member is arranged to pass through the through-hole portion (first through-hole portion) 86d. The length Z5 of the pin 88 is longer than the diameter of the spherical surface 86e (see Figure 7A), and the two ends (88a and 88b) of the pin 88 extend outside the spherical surface 86e. When the rotational force along the rotation direction R is transmitted from the drive head 14 to the coupling member 86, the through-hole portion 86d (its side surfaces 86d1 and 86d2) contacts the cylindrical surface 88c of the pin 88 and transmits the rotational force to the pin 88. The two end portions (88a and 88b) of the pin 88 contact the side surface 87f1 of the drive side flange 87 (details of which are described below) and the pin 88 transmits the rotational force to the drive side flange 87.

That is, the pin 88 is a transmission member that transmits the rotational force (driving force) of the coupling member 86 to the driving-side flange 87 .

(Drum unit and drive side flange)

The drum unit U2 to which the coupling member 86 and the pin 88 are attached is described in detail with reference to Figures 8A to 8C. Figures 8A to 8C are explanatory diagrams of the structure of the drum unit U2. Figure 8A is an exploded perspective view as viewed from the drive side. Figure 8B is an exploded perspective view as viewed from the non-drive side, and Figure 8C is a perspective view as viewed from the drive side.

As shown in Figures 8A to 8C, the drum unit U2 is composed of a drum 62, a drive side flange 87, a non-drive side flange 64, and a ground plate 65. The drum 62 is a conductive member made of, for example, Al, and its outer peripheral surface is covered with a photoconductive layer. The drum 62 can be hollow or solid.

Regarding the drive-side flange 87, as shown in FIG8A , on the drive side of the drum 62, a fixing portion 87d fits into the opening 62a1 of the drum 62 and is secured to the drum 62 using adhesive, caulking, or other methods. When the drive-side flange 87 rotates, the drum 62 rotates integrally therewith. The drive-side flange 87 is secured to the drum 62 such that the rotation axis of the drive-side flange 87 is coaxial (on the same straight line) with the axis L1 of the drum 62. Therefore, the rotation axis of the drive-side flange 87 will hereinafter be referred to as the axis L1.

Similarly, the non-drive side flange 64 is arranged at the end of the non-drive side of the drum 62 so that the rotation axis of the non-drive side flange 64 is coaxial with the drum 62. With regard to the non-drive side flange 64, as shown in Figure 8B, the fixed portion 64a is fitted into the opening 62a2 of the drum 62 and is fixed to the drum 62 by adhesive, caulking or other methods. An electrically conductive (mainly metal) grounding plate 65 is arranged in the non-drive side flange 64. The grounding plate 65 contacts the inner peripheral surface of the drum 62 and further electrically connects the device body A to the drum 62 via an unshown electrical contact.

The configuration of the drive-side flange 87 will be described with reference to Figures 9A to 9E. Figures 9A to 9E are explanatory diagrams of the drive-side flange 87. Figure 9A is a perspective view, Figure 9B is a front view as viewed from the outside of the drive side, Figure 9D is a cross-sectional view taken along line IXD-IXD in Figure 9B, Figure 9C is a cross-sectional view taken along line IXC-IXC in Figure 9B, and Figure 9E is an enlarged view of a portion (IXE) of Figure 9D.

As shown in FIG9C , the drive-side flange 87 has a fixed portion 87d fixed to the drum 62, allowing the drive-side flange 87 to rotate integrally with the drum 62. As shown in FIG9A and FIG9B , the drive-side flange 87 has a cylindrical portion (a cylindrical portion formed in a generally cylindrical shape) 87a, the central axis of which is the axis L1. The cylindrical portion is arranged closer to the drive side than the fixed portion 87d (located further outward of the drum 62 than the fixed portion 87d, see FIG8A ). The drive-side flange 87 also has a second cylindrical portion (a second cylindrical portion formed in a generally cylindrical shape) 87b, which is arranged radially outward of the cylindrical portion 87a. The drive-side flange 87 also has an annular groove portion (a substantially annular groove portion, a second groove portion) 87c, which is provided between the cylindrical portion 87a and the second cylindrical portion 87b.

The cylindrical portion 87a has a hollow portion 87e and a pair of groove portions 87f on the inner side in the radial direction. The hollow portion 87e and the pair of groove portions 87f respectively accommodate the connecting portion 86c of the coupling member 86 shown in Figures 7A to 7C and the two end portions (88a and 88b) of the pin 88.

The hollow portion 87e has an inner peripheral surface 87e1 whose central axis is the axis L1, and a bottom surface 87e2 that intersects the axis L1 (in this embodiment, perpendicularly). The bottom surface 87e2 is located at a position where the axis L1 passes through. The inner peripheral surface 87e1 refers to the inner surface of the edge of the cylindrical portion 87a. The bottom surface 87e2 refers to the bottom portion that forms the bottom of the hollow portion 87e.

The groove portion 87f is formed by cutting the inner peripheral surface 87e1. That is, the groove portion 87f is formed by recessing the edge of the cylindrical portion 87a forming the hollow portion 87e in the outer side in the radial direction. Two groove portions 87f are formed along the axis L1, and the two groove portions 87f are arranged to be 180 degrees from each other via the axis L1. The bottom portion 87f3 is provided at one end portion of the non-driving side of the groove portion 87f, and the bottom portion 87f3 is a plane that intersects (in this embodiment, perpendicularly intersects) the axis L1. The bottom portion 87f3 is a portion that becomes the bottom of the groove portion 87f.

The groove portion 87f is open toward the side (driving side) opposite to the side of the fixed portion 87d (the groove portion 87f is formed to reach one end of the cylindrical portion 87a), and the driving side end of the groove portion 87f becomes an opening 87g. The groove portion 87f also has side surfaces 87f1 and 87f2 along the direction of the axis L1 and an opposing surface 87f4 that is parallel to the axis L1 and faces each other in the direction of the axis L1.

As shown in FIG. 9E , a narrowed portion 87 h having a width Z2 narrower than a distance (width Z1 ) between the side surface 87 f 1 and the side surface 87 f 2 is provided between the bottom portion 87 f 3 and the opening 87 g .

Stopper portions 87h1 and 87h2 are provided on the non-driving side (bottom portion 87f3 side) of the narrowed portion 87h, and have a stopper angle θ1 relative to the axis L1. Entrance portions 87h3 and 87h4 are provided on the driving side of the narrowed portion 87h, and have an insertion angle θ2 relative to the axis L1. Stopper portions 87h1 and 87h2 and entrance portions 87h3 and 87h4 are arranged so as to satisfy the relationship of stopper angle θ1 > insertion angle θ2.

9C, the second cylindrical portion 87b has a gear portion 87b1 on its outer peripheral side for transmitting rotation to the developing roller 32 (see FIG2). The annular groove portion 87c has a supported portion 87c1 rotatably supported by a bearing member 76 described later.

(Attachment of coupling member and pin)

A method of attaching the connecting member 86 and the pin 88 to the drum unit U2 is described with reference to Figures 10A to 10C and Figures 11A to 11C. Figures 10A to 10C are explanatory diagrams showing the assembly of the connecting member 86 and the pin 88 to the drum unit U2. Figure 10A is a perspective view showing the state before assembly, and Figure 10B is a perspective view showing the state after assembly. Figure 10C is an XC sectional view obtained along the XC virtual plane of Figure 10B (a plane in which the axis of the pin 88 (see Figure 10A) is the normal line), and the area near the hollow portion 87e is enlarged. Figure 10C shows the states before and after assembling the connecting member 86 and the pin 88, wherein the state before assembly (Figure 10A) is shown by a solid line and the state after assembly (Figure 10B) is shown by a virtual line (double dotted line).

11A to 11C are explanatory diagrams (of the drum unit U1) showing a state in which the coupling member 86 and the pin 88 are assembled to the drum unit U2. FIG11A is a front view as viewed from the driving side, FIG11B is a cross-sectional view (XIB) taken along line XIB-XIB of FIG11A, and FIG11C is a cross-sectional view (XIC) taken along line XIC-XIC of FIG11A.

When the coupling member 86 and the pin 88 are assembled to the drum unit U2, as shown in FIG10A , the pin 88 and the coupling member 86 are inserted into the drive-side flange 87 along the axis L1, with the pin 88 inserted into the through-hole portion 87 d. The hollow portion 87 e opens on the outer side (drive side) of the drum 62 (i.e., the right side in FIG10A ) in the direction of the axis L1. The coupling member 86 is inserted into the hollow portion 87 e from the right along the axis L1.

The connecting portion 86c is inserted into the hollow portion 87e and the pin 88 is inserted into the groove portion 87f, wherein the phases of the pin 88 (both end portions 88a and 88b thereof) and the groove portion 87f in the rotation direction R are aligned.

The two groove portions 87 f , into which the end portions of the pin 88 are respectively inserted, are arranged symmetrically with respect to the center of the cylindrical portion 87 a (ie, the axis L1 ).

During the insertion of the pin 88 into the groove portion 87f, as shown in FIG10C , resistance is generated during the insertion of the pin 88 into the groove portion 87f because the width Z2 of the narrowed portion 87h is smaller than the diameter of the pin 88. The coupling member 86 and the pin 88 are inserted while elastically deforming the portion near the narrowed portion 87h due to the application of an insertion force that overcomes the resistance against the pin 88. Then, the pin 88 passes through the narrowed portion 87h, and the insertion of the pin 88 into the groove portion 87f and the insertion of the connecting portion 86c into the hollow portion 87e are completed.

As shown in Figures 11A to 11C, the coupling member 86 and the pin 88 are assembled to the drum unit U2, and the drum unit U1 is completed. At this time, the coupling member 86 is positioned in the radial direction, and the connecting portion 86c is supported by the inner peripheral surface 87e1. When the connecting portion 86c contacts the bottom surface 87e2, the coupling member 86 does not slide out on the non-driven side because the bottom surface 87e2 does not pass through. As mentioned above, the bottom surface 87e2 is arranged in a position passed through by the axis L1, but the bottom surface 87e2 can be arranged in a position not passed through by the axis L1. In this arrangement, the structure in which the bottom surface 87e2 is inclined relative to the axis L1 is more ideal than the structure in which the bottom surface 87e2 is perpendicular to the axis L1. This is because the former can make the bottom surface 87e2 as parallel to the surface of the connecting portion 86c as much as possible and can support the connecting portion 86c more stably. Because the through-hole portion 86d (its non-driving side end surface 86d3, see Figure 11C) contacts the pin 88, the coupling member 86 does not slide out on the driving side. Because both side surfaces (86d1 and 86d2) of the through-hole portion 86d contact the pin 88, the coupling member 86 is positioned (with a small clearance) in the rotation direction R. The pin 88 does not slide out in the direction of the axis L1 due to the bottom portion 87f3 and the narrowed portion 87h (its stop portions 87h1 and 87h2), and the pin 88 is positioned in the axial direction of the pin 88 by the opposing surface 87f4. The pin 88 is also positioned in the rotation direction R by the two side surfaces 87f1 and 87f2 of the groove portion 87f. When the rotation along the rotation direction R is input into the coupling member 86, the rotational force is transmitted to the side surface 87f1 of the groove portion 87f via the pin 88. That is, the side surface 87f1 acts as the part to which the rotational force is transmitted.

Because the relationship of stop angle θ1 > insertion angle θ2 is satisfied, the insertion force required to insert the pin 88 into the groove portion 87f can be made smaller than the force required to remove the pin 88 from the groove portion 87f. Therefore, the insertion force during assembly of the pin 88 to the drive-side flange 87 can be reduced, and the pin 88 can be less likely to slip out of the drive-side flange 87. It is possible to have only one of the two groove portions 87f have the narrowed portion 87h to prevent the pin 88 from slipping out. However, from the perspective of reliably preventing the pin 88 from slipping out, it is ideal to provide the narrowed portion 87h in both groove portions 87f.

With the above-described configuration, the coupling member 86 and the pin 88 are assembled so that these parts do not slip out of the drum unit U2 and the rotational force is transmitted from the coupling member 86 to the drive-side flange 87. Because the cylindrical inner circumferential surface 87e1 supports the spherical surface 86e, the coupling member 86 can tilt relative to the drive-side flange 87 about the spherical center 86f (directions K1, K2, and the combined direction of these directions in Figures 11A and 11B). In order to enable the coupling member 86 to tilt in the direction of K1, a gap S1 is provided in the direction of the axis L2 between the pin 88 and the through-hole portion 86d (the non-drive-side end surface 86d3 and the drive-side end surface 86d4) (see also Figures 7A to 7C).

(Structure of cleaning unit)

Next, a method of assembling the drum unit U1 to the cleaning unit 60 will be described with reference to Fig. 12. Fig. 12 is an exploded perspective view of the cleaning unit 60.

As shown in Figure 12, on the non-driving side of the cleaning unit 60, the bearing portion 64b (see Figure 8B) of the non-driving side flange 64 of the drum unit U1 is rotatably supported by the drum shaft 78. The drum shaft 78 is fixed to a supporting portion 71b, which is provided on the non-driving side of the cleaning frame 71 by press-fitting.

A supporting member 76 is provided on the driving side of the cleaning unit 60, and the supporting member 76 contacts and supports the driving side flange 87. A wall surface (flat portion) 76h of the supporting member 76 is fixed to the cleaning frame 71 with a screw 90. The supporting portion 76a of the supporting member 76 fits the annular groove portion 87c of the driving side flange 87. In this way, the drum unit U1 is rotatably supported by the cleaning frame 71 via the drum shaft 78 and the supporting member 76.

As described above, each part of the driving side flange 87 can be arranged as follows by providing the annular groove portion 87c in the driving side flange 87. That is, the portion supported by the supporting member 76 (its supporting portion 76a) (the supported portion 87c1) can be overlapped by the gear portion 87b1, the hollow portion 87e (for these, see Figure 11B) and the groove portion 87f in the direction of the axis L1. That is, as shown in Figure 21, the positions of the annular groove portion 87c (the supported portion 87c1), the gear portion 87b1, and the hollow portion 87e overlap in the area A1 along the axis L1. Therefore, compared with the case where the supported portion supported by the supporting member 76 is provided on the outside in the direction of the axis L1 of the gear portion 87b1 and the hollow portion 87e, the size of the box B can be reduced in the direction of the axis L1. Because the gear portion 87b1 and the groove portion 87f overlap in the direction of the axis L1, the force received on the side surface 87f1 (see FIG. 9E ) of the groove portion 87f can be stably transmitted to the gear portion 87b1. With this configuration, with respect to the radial direction around the axis L1, the gear portion 87b1 is arranged outside the annular groove portion 87c, and the annular groove portion 87c is arranged outside the hollow portion 87e and the groove portion 87f.

Although the support member 76 is fixed to the cleaning frame 71 with the screws 90 in this embodiment, the support member 76 may be fixed using an adhesive or molten resin. Alternatively, the cleaning frame 71 and the support member 76 may be integrated with each other.

The cleaning unit 60 and the developing unit 20 are connected as described above, and the cartridge B is completed.

As described above, according to the configuration of this embodiment, the coupling member 86 and the pin 88 can be assembled to the drum unit U2 from the outside of the drive side (outside in the axial direction relative to the photosensitive drum: right side in Figure 10A). Therefore, the assembly process of the cartridge B can be simplified for the following reasons.

As described above, because the coupling member 86 is capable of tilting, there is a possibility that the coupling member 86 may collide with an assembly tool or a part to be assembled during the assembly process of the cartridge B. Therefore, in the downstream process of assembling the coupling member 86, it is necessary to control the tilt of the coupling member 86 by hand, using a tool, or a device. Once the coupling member 86 is assembled to the drive-side flange 87, the downstream process of assembling the cartridge B must be performed while controlling the tilt of the coupling member 86, which is a burden on the operating process.

Therefore, if the assembly of the coupling member 86 can be performed as far downstream as possible in the assembly process of the cartridge B, the number of processes required to control the inclination of the coupling member 86 can be reduced.

With the configuration of this embodiment, the coupling member 86 can be attached to the driving-side flange 87 after the driving-side flange 87 is fixed to the drum 62. In this case, the process of fixing the driving-side flange 87 to the drum 62 can be simplified compared to the case where the coupling member 86 is attached to the driving-side flange 87 before the driving-side flange 87 is attached to the drum 62. That is, because the coupling member 86 is not present in the driving-side flange 87, the coupling member 86 does not hinder the operation when the driving-side flange 87 is fixed to the drum 62.

Alternatively, the coupling member 86 and the pin 88 may be assembled after the drum unit U2 is assembled into the cleaning unit 60. In this case, it is also possible to simplify the assembly process of assembling the drum unit U2 into the cleaning unit 60. Alternatively, the coupling member 86 and the pin 88 may be assembled after the cleaning unit 60 and the developing unit 20 are connected.

Although the coupling member 86 is prevented from sliding out toward the non-driving side by the bottom surface 87e2 in this embodiment, it may be prevented from sliding out by the pin 88 and the through-hole portion 86d (its driving side end surface 86d4), such as a stopper for the driving side. However, since the gap S1 is provided between the pin 88 and the through-hole portion 86d (its driving side end surface 86d4) as described above, the structure in which the coupling member 86 is prevented from sliding out by the bottom surface 87e2 as in this embodiment enables accurate positioning of the coupling member 86.

As shown in FIGS. 13A to 13C , a cantilever portion 187 k may be provided in the driving-side flange 187 for a stopper for the driving side of the coupling member 86 .

In this case, it is possible to prevent the coupling member 86 from sliding out on the driving side by setting the distance between the cantilever portions 187k to be smaller than that of the connecting portions 86c.

The cantilever portion 187k is a protruding portion extending from the inner wall of the hollow portion 187e (the inner peripheral surface of the cylindrical portion) toward the interior of the hollow portion 187e (radially inward, toward the center of the cylindrical portion). The cantilever portion 187k contacts the coupling member 86 and prevents the coupling member 86 from moving outside the drum 62 (the right side in FIG. 13C ). In other words, because the cantilever portion 187k is captured by the coupling member 86, the coupling member 86 is prevented from slipping out of the drive-side flange 187. The drive-side flange 187 has a gear portion 187b1 that is identical to the gear portion 87b1.

Therefore, the coupling member 86 can be positioned more accurately than in the case where it is prevented from sliding out toward the driving side by the pin 88 and the through-hole portion 86 d (the non-driving side end surface 86 d 3 thereof).

Although the driving-side flange 87 is an integral member in this embodiment, the two parts may be integrated. This exemplary configuration will be described with reference to Figures 14A to 14C. Figures 14A to 14C are explanatory diagrams of a configuration in which the cover member 489 is provided separately from the driving-side flange 487. Figures 14A and 14B are exploded perspective views, and Figure 14C is a cross-sectional view of a state in which the pin 88 is assembled.

In the exemplary configuration shown in Figures 14A to 14C, a cover member 489 is fixed to the drive-side flange 487. The cover member 489 has a bottom surface 489e2 and a bottom portion 489f3. When the cover member 489 is fixed to the drive-side flange 487, the bottom surface 489e2 forms the bottom of the hollow portion 487e. The bottom portion 489f3 forms a portion of the groove portion 487f. The drive-side flange 487 has a gear portion 487b1, which is identical to the gear portion 87b1.

With this configuration, the hole 87m (see FIG. 9C ) on the mold for forming the narrowed portion 87h shown in FIG. 9A to FIG. 9E can be omitted, simplifying the molding of the drive-side flange 487. When the cover member 489 is provided, the configuration shown in FIG. 14C can also prevent the pin 88 from sliding out. In this exemplary configuration, the narrowed portion 487h is formed by the protrusion 489h extending from the bottom surface 489f3 of the cover member 489 and the stop surface 487h1. In this case, as shown in FIG. 14C , the pin 88 is first inserted into the groove portion 487f from the opening 487g in the direction of arrow W1. Then, as the pin 88 rotates along the rotational direction R with the coupling member 86 (not shown), it passes over the narrowed portion 487h formed by the protrusion 489h and the stop surface 487h1, thereby completing the assembly of the coupling member 86 and the pin 88.

As shown in Figure 22, the groove portion 487f has a curved portion Z3. Specifically, the groove portion 487f has a first portion Z1 extending in the axial direction of the photosensitive drum, and a second portion Z2 located closer to the bottom surface 489f3 than the first portion Z1 and extending in the circumferential direction of the cylindrical portion. The curved portion Z3 is located between the first portion Z1 and the second portion Z2, where the direction in which the groove portion 487f extends changes. In other words, the curved portion Z3 is the portion where the groove portion 487f bends. The narrowed portion 487h is located in the second portion Z2 of the groove portion 487f.

[Second embodiment]

A second embodiment according to the present invention will be described with reference to Figures 15A to 16B. Since the configuration of this embodiment is the same as that of the first embodiment except for the drive-side flange 287, a description of this configuration will be omitted. Regarding the drive-side flange 287, since the configuration is the same as that of the first embodiment except for the groove portion 287f and the narrowed portion 287h, a description thereof will be omitted.

Figures 15A and 15B are perspective explanatory diagrams of the drum unit U22 provided with the drive-side flange 287 according to this embodiment. As shown in Figure 15A, the drive-side flange 287 has a pair of groove portions 287f that open to the drive side (outside of the photosensitive drum in the axial direction) in the opening 287g as in the first embodiment. The pair of groove portions 287f are formed at the edge of the cylindrical portion 287a (the inner peripheral surface forming the hollow portion 287e).

Here, as shown in Figure 15B, the side surface 287f2 (upstream in the rotation direction R) of the two side surfaces (287f1 and 287f2) of the groove portion 287f that does not serve as the portion to which the rotational force is transmitted is formed as a portion of the elastic deformation portion 287k. The elastic deformation portion 287k extends from the bottom portion 287f3 on the driving side and is not continuously connected to the cylindrical portion 287a. In addition, the elastic deformation portion 287k and the cylindrical portion 287a also have a gap V1 in the direction of the arrow V. Therefore, the elastic deformation portion 287k easily elastically deforms in the direction of the arrow V in Figure 15B at the bottom portion 287f3. A protrusion 287h1 is provided from the side surface 287f2, extending toward the opposite side surface 287f1. A narrowing portion 287h is formed between the protrusion 287h1 and the side surface 287f1, and the distance Z7 of the narrowing portion 287h is narrower than the diameter of the pin 88. An inclined portion 287h2 inclined relative to the axis L1 is provided on the driving side (opening 287g side) of the protruding portion 287h1, and a stopper portion 287h3 perpendicularly intersecting the axis L1 is provided on the non-driving side (bottom portion 287f3 side). The driving side flange 287 has a gear portion 287b1 that is identical to the gear portion 87b1.

When the coupling member 86 and the pin 88 are assembled to the driving side flange 287, the pin 88 contacts the inclined portion 287h2 and the elastically deformable portion 287k deforms in the direction of arrow V. Then, the narrowed portion 287h expands to allow the pin 88 to pass therethrough. Because the stopper portion 287h3 intersects the axis L1 at right angles, the elastically deformable portion 287k is not easily deformed in the direction of arrow V even if the pin 88 attempts to pass through the driving side.

In this embodiment, as described above, the elastic deformation portion 287k is provided so that the narrowed portion 287h is easily expanded when the pin 88 is inserted. Compared with the case where the elastic deformation portion 287k is not provided (first embodiment), the burden during assembly of the pin 88 to the drum unit U22 can be reduced.

Compared to the present embodiment, the elastically deformable portion may be provided on the side of side surface 287f1, which serves as the portion to which the rotational force is transmitted. However, in this case, the elastically deformable portion may deform when the rotational force is transmitted from pin 88, and pin 88 may slide over protruding portion 287h1. Therefore, it is more appropriate to provide the elastically deformable portion on the side of side surface 287f2 as in the present embodiment.

Other forms of this embodiment will be described with reference to Figures 16A and 16B. Figures 16A and 16B are perspective explanatory views of the drum unit U32 including the driving-side flange 387.

In the form of the drive-side flange 387 shown in Figures 16A and 16B, the drive-side flange 387 has a cylindrical portion 387a, a hollow portion 397e, a narrowed portion 387h, and the like. The drive-side flange 387 is configured to have an elastically deformable portion 387k that is not continuously connected to the cylindrical portion 387a. The elastically deformable portion 387k is provided on the side of the opposing surface 387f4 opposite the axis L1, and the elastically deformable portion 387k causes the protruding portion 387h1 to protrude from the opposing surface 387f4 toward the axis L1. In this case, the width Z32 shown in Figures 16A and 16B (the distance between the two opposing protruding portions 387h1) is defined as the narrowed portion 387h, and the protruding portion 387h1 is provided so that the width Z32 is smaller than the entire length Z5 of the pin 88 (see Figures 7A to 7C). The driving-side flange 387 has a gear portion 387 b 1 that is identical to the gear portion 87 b 1 .

[Third embodiment]

A third embodiment according to the present invention will be described with reference to FIG17A to FIG17D. Since the configuration of this embodiment is the same as that of the first embodiment except for the drive-side flange 587 (687), the description of the configuration will be omitted. With respect to the drive-side flange 587 (687), since the configuration is the same as that of the first embodiment except for the groove portion 587f (687f), the description thereof will be omitted.

Figures 17A to 17D are perspective views illustrating a method for fixing the drive-side flange 587, the drive-side flange 687, and the pin 88 in this embodiment. Figures 17A and 17C are perspective views of the drive-side flange 587 and the drive-side flange 687, illustrating an example of this embodiment. Figures 17B and 17D are perspective views illustrating a state in which the pin 88 stops sliding out after being inserted into the drive-side flange 587 (687) of Figures 17A and 17C.

As shown in Figures 17A and 17C, the cylindrical portion 587a (687a) of the driving side flange 587 (687) has a pair of groove portions 587f (687f). An opening surface 587g1 (687g1) is provided on the radially outer side of the groove portion 587f (687f), and the opening surface is located closer to the driving side than the bottom portion 587f3 (687f3). The driving side flange 587 (687) has a gear portion 587b1 (687b1) that is the same as the gear portion 87b1.

In this embodiment, the groove portion 587f (687f) is defined so as to reach the opening surface 587g1 (687g1) along the direction of the axis L1. The opening 587g (687g) is located at the same position as the opening surface 587g1 (687g1) in the direction of the axis L1, and the opening 587g (687g) becomes the driving side end of the groove portion 587f (687f). A protrusion 587i (687i) is provided in the opening surface 587g1 (687g1), the protrusion 587i protruding on the driving side, wherein a gap exists between the cylindrical portion 587a (687a) and the protrusion 587i. An inclined portion 587il (687il) is provided in the protrusion 587i (687i), the inclined portion being inclined relative to the axis L1 so that the normal faces in the direction opposite to the direction of the groove portion 587f (687f). The protruding portion 587i (687i) is made of a thermoplastic resin (e.g., polyacetal). The portion of the driving side flange 587 (687) other than the protruding portion 587i (687i) may be made of the same material as the protruding portion 587i (687i) or may be made of another material integrally formed by two-color molding or the like.

After the pin 88 is inserted into the groove portion 587f (687f) of the drive side flange 587 (687), pressure and heat are applied to the protrusion 587i (687i) made of thermoplastic resin (heat-deformable resin) in a direction perpendicular to the inclined portion 587il (687il). Then, as shown in Figures 17B and 17D, the protrusion 587i (687i) is deformed toward the groove portion 587f (687f) to form a stop portion 587h (687h). Therefore, the opening 587g (687g) is closed and can prevent the pin 88 from sliding out. The protrusion 587i (687i) is a heat-deformable portion that prevents the pin 88 from moving outside the axial direction of the photosensitive drum (to the right in Figure 17D) when it is thermally deformed.

As described above, according to the present embodiment, since the coupling member 86 and the pin 88 can be assembled on the driving side of the drum unit U52 from the outside, the assemblability of the drum unit U52 is improved as in the first and second embodiments.

Since the driving side flange 587 can be manufactured in a simpler shape compared with the above-described embodiment, mold manufacturing is easier and it is easy to stabilize the accuracy of the part after molding.

Alternatively, the pin 88 can be prevented from sliding out by other methods without deforming the protruding portion made of thermoplastic resin as in the present embodiment. Other stop structures of the pin 88 are described with reference to Figures 18A to 19B. Figures 18A to 18C are explanatory diagrams of an exemplary stop structure of the pin 88. Figure 18A is an exploded perspective view, and Figures 18B and 18C are perspective views of a state in which the pin 88 has been assembled. Figures 19A and 19B are explanatory diagrams showing another exemplary structure. Figure 19A is an exploded perspective view, and Figure 19B is a perspective view of a state in which the pin 88 has been assembled. As an exemplary stop structure of the pin 88, as shown in Figure 18B, after the pin 88 is inserted into the groove portion 787f of the drive side flange 787 together with the coupling member 86 (not shown), an adhesive sealant H, such as a hot melt or adhesive, can be applied. Alternatively, as shown in Figure 18C, the resin member 789 can be inserted and fixed by press fitting, bonding, welding, etc. As shown in Figures 19A and 19B, a cylindrical portion 889a including a groove portion 889f and a stop portion 889h can be formed in the upper cover member 889, and the upper cover member 889 can be fixed to the drive side flange 887, which has a bottom portion 887f3. The upper cover member 889 is a fixing member that is attached and fixed to the drive side flange 887 from the drive side (outside the photosensitive drum). The upper cover member 889 is also a regulating member that regulates the movement (sliding out) of the pin 88. The drive side flange 787 has a gear portion 787b1 that is identical to the gear portion 87b1, and the drive side flange 887 has a gear portion 887b1 that is identical to the gear portion 87b1.

[Fourth embodiment]

A fourth embodiment of the present invention will be described with reference to Figures 20A to 20C. Figures 20A to 20C are explanatory diagrams illustrating the assembly of the drum unit U91 in this embodiment. The assembly process is shown in perspective views in the order of Figures 20A to 20C. In this embodiment, as shown in Figures 20A to 20C, the shape of the drive-side flange 987 and the method of assembling the pin 88 differ from those in the above-described embodiment, and therefore, descriptions other than these will be omitted.

In the driving side flange 987, as shown in FIG20A , a gear portion 987b1 and a cylindrical portion 987a are provided on the driving side of the fixing portion 987d to fix the drum 62. The cylindrical portion 987a has a hollow portion 987e for supporting the connecting portion 86c of the coupling member 86 inward in the radial direction as in the first embodiment. The cylindrical portion 987a has a through hole (second through hole portion) 987f that penetrates from the hollow portion 987e to the outer peripheral surface 987a1 and perpendicularly intersects the axis L1.

That is, each of the two through holes 987f passes through the edge of the cylindrical portion 987a and communicates with the hollow portion 987e. The two through holes 987f are arranged 180 degrees apart from each other via the axis L1. In other words, the two through holes 987f are positioned symmetrically about the axis L1 (the axis L1 is the center of the cylindrical portion 987a).

The diameter of each of the two through holes 987f is slightly smaller than the diameter of the pin 88.

When coupling member 86 and pin 88 are assembled to drive side flange 987, as shown in Figure 20B, the connecting portion 86c of coupling member 86 is first inserted in hollow portion 987e. Then, pin 88 is inserted toward hollow portion 987e from a through hole in through hole (second through hole portion) 987f. As shown in Figure 20C, pin 88 is inserted to arrive at through hole (second through hole portion) 987f (not shown in Figure 20C) on the opposite side via through hole (first through hole portion) 86d of coupling member 86. Because pin 88 is press-fitted in through hole 987f, pin 88 is prevented from sliding out relative to drive side flange 987. Therefore, the assembly of coupling member 86 and pin 88 to drive side flange 987 is completed.

As described above, according to the present embodiment, it is possible to assemble the coupling member 86 from the driving side of the drum unit U92. Therefore, as in the first embodiment, the assembly of the drum unit U92 becomes simpler.

Although pin 88 is secured by press-fitting it into through-hole 987f in this embodiment, one of through-holes 987f may have a slightly larger diameter, and pin 88 may simply be press-fitted into the other of through-holes 987f. Alternatively, any securing method other than press-fitting may be used. For example, the diameter of through-hole 987f may be slightly larger than the diameter of pin 88, and adhesive may be applied to the gap between pin 88 and through-hole 987f after pin 88 is inserted into through-hole 987f. Furthermore, any one of pins 88 may be formed with a male thread at its end and inserted into one of through-holes 987f while being tapped to secure pin 88.

While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The following claims are to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.

This application claims the benefit of Japanese Patent Application No. 2015-047603, filed on March 10, 2015, and Japanese Patent Application No. 2016-028430, filed on February 17, 2016, which are hereby incorporated by reference herein in their entirety.

Claims (9)

1. A method of attaching a connecting member including a through-hole portion to a drum unit including a photosensitive drum and a flange member, wherein the flange member includes a fixing portion fixed to one end of the photosensitive drum, a cylindrical portion having a hollow portion formed therein, and a groove portion disposed at an edge of the cylindrical portion, wherein the groove portion and the hollow portion open outward in an axial direction toward the photosensitive drum, wherein the groove portion has: (i) an opening at an end of the groove portion opening outward in the axial direction, (ii) a bottom portion at the opposite end of the opening, (iii) two side surfaces extending along the axial direction and spaced apart by a distance Z1, and (iv) a narrowing portion, the width Z2 of which is narrower than the distance Z1, the method comprising: (1) A pin, which is a cylindrical member with a diameter of , is inserted into the through hole portion, and the pin transmits the rotational force of the connecting member to the drum unit by contacting the cylindrical surface of the pin with the through hole portion. (2) Insert the end of the pin inserted in the through hole into the groove, and insert the connecting member into the hollow part; and (3) The connecting member is connected to the flange member, so that the inclination angle of the connecting member relative to the axial direction and the pin can be varied. in, During the insertion process of the pin into the slot, the end of the cylindrical surface of the pin contacts the two side surfaces of the slot, and the pin passes through the narrowed portion, and Before the pin passes through the narrowed portion, the width Z2 of the narrowed portion is smaller than the diameter of the pin. 2. The method according to claim 1, wherein a stop portion having a stop angle θ1 relative to the axial direction is disposed on the bottom portion side of the narrowing portion, and an inlet portion having an insertion angle θ2 relative to the axial direction is disposed on the opening side of the narrowing portion, wherein θ1>θ2. 3. A drum unit for use in an electrophotographic imaging apparatus, the drum unit comprising: Photosensitive drum; Flange components; The connecting member includes a through-hole portion; and As a cylindrical member with a diameter of , the pin is configured to transmit the rotational force of the connecting member to the flange member, wherein The flange member includes: a fixing portion fixed to one end of the photosensitive drum; a cylindrical portion having a hollow portion formed therein; and a groove portion disposed at the edge of the cylindrical portion. The pin is inserted into the through hole, and the cylindrical surface of the pin can contact the through hole. The hollow portion opens outward in the axial direction of the photosensitive drum, and the connecting member is inserted into the hollow portion. The groove portion opens outward in the axial direction, and the end of the pin is inserted into the groove portion. The connecting member is connected to the flange member, allowing the angle of inclination of the connecting member relative to the axial direction and the pin to vary. The groove portion includes: (i) an opening at one end of the groove portion opening outward in the axial direction; (ii) a bottom portion at the opposite end of the opening; (iii) two side surfaces extending along the axial direction and spaced apart by a distance Z1; and (iv) a narrowing portion, the width Z2 of which is narrower than the distance Z1 and smaller than the distance Z1, and the narrowing portion is disposed between the opening and the bottom portion. The end of the cylindrical surface of the pin contacts the two side surfaces of the groove portion, and The portion of the flange member near the narrowing section is capable of elastic deformation to expand the insertion force of the pin into the slot. 4. The drum unit according to claim 3, wherein a stop portion having a stop angle θ1 relative to the axial direction is provided on the bottom portion side of the narrowing portion, and an inlet portion having an insertion angle θ2 relative to the axial direction is provided on the opening side of the narrowing portion, wherein θ1>θ2. 5. The drum unit according to claim 3 or 4, wherein movement of the pin is prevented by the narrowing portion. 6. A method of attaching a connecting member including a through-hole portion to a drum unit, wherein the drum unit includes a photosensitive drum, a flange member, and a cover member internally attached to the flange member in an axial direction, wherein the flange member includes a fixing portion fixed to one end of the photosensitive drum, a cylindrical portion having a hollow portion, and a groove portion disposed at an edge of the cylindrical portion, wherein the groove portion and the hollow portion open outward in an axial direction to the photosensitive drum, the method comprising: (1) A pin, which is a cylindrical member with a diameter of , is inserted into the through hole portion, and the pin transmits the rotational force of the connecting member to the drum unit by contacting the cylindrical surface of the pin with the through hole portion. (2) Insert the end of the pin inserted in the through hole into the groove, and insert the connecting member into the hollow part; and (3) The connecting member is connected to the flange member, so that the inclination angle of the connecting member relative to the axial direction and the pin can be varied. in, The groove portion has a narrowed portion formed by the protrusion of the cover member. Allow the pin to pass through the narrowed portion, and Before the pin passes through the narrowed portion, the width Z2 of the narrowed portion is smaller than the diameter of the pin. 7. The method of claim 6, wherein the groove portion has: a first portion extending along the axial direction of the photosensitive drum; a second portion closer to the bottom surface than the first portion and extending along the circumferential direction of the cylindrical portion; and a curved portion located between the first portion and the second portion, wherein the groove portion bends at the curved portion, wherein the narrowing portion is located in the second portion of the groove portion. 8. A drum unit for use in an electrophotographic imaging apparatus, the drum unit comprising: Photosensitive drum; Flange components; A cover member, which is internally attached to the flange member in the axial direction; The connecting member includes a through-hole portion; and As a cylindrical member with a diameter of , the pin is configured to transmit the rotational force of the connecting member to the flange member, wherein The flange member includes: a fixing portion fixed to one end of the photosensitive drum; a cylindrical portion having a hollow portion formed therein; and a groove portion disposed at the edge of the cylindrical portion. The pin is inserted into the through hole, and the cylindrical surface of the pin can contact the through hole. The hollow portion opens outward in the axial direction of the photosensitive drum, and the connecting member is inserted into the hollow portion. The groove portion opens outward in the axial direction, and the end of the pin is inserted into the groove portion. The connecting member is connected to the flange member, allowing the angle of inclination of the connecting member relative to the axial direction and the pin to vary. in The groove portion has a narrowed portion formed by the protrusion of the cover member. Allow the pin to pass through the narrowed portion, and Before the pin passes through the narrowed portion, the width Z2 of the narrowed portion is smaller than the diameter of the pin. 9. The drum unit of claim 8, wherein the groove portion has: a first portion extending along the axial direction of the photosensitive drum; a second portion closer to the bottom surface than the first portion and extending along the circumferential direction of the cylindrical portion; and a curved portion located between the first portion and the second portion, wherein the groove portion bends at the curved portion, wherein the narrowing portion is located in the second portion of the groove portion.