Drum unit, cartridge

Abstract

To develop a conventional coupling that transmits a driving force.SOLUTION: A coupling member includes a support part that movably supports a driving force receiving part that receives a driving force.SELECTED DRAWING: Figure 60

Description

[Technical Field]

[0001] The present invention relates to a process cartridge or the like used in an electrophotographic image forming apparatus. [Background technology]

[0002] In electrophotographic image forming apparatuses, elements such as a photosensitive drum and a developing roller, which are rotating bodies involved in image formation, are integrated into a cartridge that is detachably mountable to the image forming apparatus main body (hereinafter referred to as the apparatus main body). In such a configuration, a configuration is often adopted in which a driving force is received from the apparatus main body to rotate the photosensitive drum in the cartridge. In this case, a known configuration is to transmit the driving force by engaging a coupling member on the cartridge side with a driving force transmission part such as a drive pin on the apparatus main body.

[0003] For example, Patent Document 1 discloses a cartridge that includes a coupling member that is provided at the end of a photosensitive drum and is tiltable with respect to the rotation axis of the photosensitive drum. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-233867 Summary of the Invention [Problem to be solved by the invention]

[0005] The aim is to develop the above-mentioned prior art. [Means for solving the problem]

[0006] A typical configuration is as follows: A drum unit detachably attached to a main body of an electrophotographic image forming apparatus, the drum unit having a drive shaft with a recessed portion, (I) a photosensitive drum; (II) a coupling member provided on the photosensitive drum, the coupling member having: (II-I) a driving force receiving portion configured to enter the recess and receive a driving force for rotating the photosensitive drum; and (II-II) a support portion that movably supports the driving force receiving portion; and At least a part of the support portion and / or at least a part of the driving force receiving portion is disposed inside the photosensitive drum. [Effects of the Invention]

[0007] The above-mentioned prior art has been developed. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic cross-sectional view of an image forming apparatus 100. FIG. [Figure 2] FIG. 2 is an external perspective view of the process cartridge 7. [Figure 3] 2 is a cross-sectional view of the process cartridge 7 cut in a direction perpendicular to the rotation axis of the photosensitive drum 1. FIG. [Figure 4] 2 is a cross-sectional view of the process cartridge taken along the center of the rotation shaft (rotation axis) of the photosensitive drum 1. FIG. [Figure 5] FIG. [Figure 6] 1 is a cross-sectional view taken along the center of the rotation axis (rotation axis line) of a main body drive shaft 101 attached to the main body of an image forming apparatus. [Figure 7] 1 is a cross-sectional view of a coupling 28 and a main body drive shaft 101 cut along the rotation center line (rotation axis). [Figure 8] 10 is a cross-sectional view of the coupling member 28 and the main body drive shaft 101 cut in a direction perpendicular to the rotation axis. [Figure 9] 1 is a cross-sectional view of a coupling 28 and a main body drive shaft 101 cut along the rotation center line (rotation axis). [Figure 10] FIG. 2 is a perspective view of a coupling member 28. [Figure 11]2 is a cross-sectional view of the coupling member 28 taken in a direction perpendicular to the rotation axis of the coupling member 28 and passing through the base 74. FIG. [Figure 12] FIG. 2 is a cross-sectional perspective view of a coupling member 28. [Figure 13] 1 is a cross-sectional view of a coupling member 28 cut along a rotation center line (rotation axis line). [Figure 14] 10 is a cross-sectional view of the coupling member 28 and the main body drive shaft 101 cut in a direction perpendicular to the rotation axis at a position passing through the base 74. FIG. [Figure 15] 1 is a cross-sectional view of a coupling member 28 and a main body drive shaft 101 cut along the rotation center line (rotation axis). [Figure 16] FIG. 10 is a perspective view illustrating the mounting of the cartridge 7 into the image forming apparatus main body 100A. [Figure 17] 10A and 10B are cross-sectional views for explaining the mounting operation of the cartridge 7 into the image forming apparatus main body 100A. [Figure 18] 10 is a cross-sectional view for explaining the operation of attaching a coupling member 28 to a main body drive shaft 101. FIG. [Figure 19] 10 is a cross-sectional view illustrating the operation of attaching the coupling member 28 to the main body drive shaft 101 when the main body drive transmission groove 101a and the engagement portion 73a are not in phase with each other and the main body drive shaft 101 rotates to be in phase with each other. [Figure 20] 10 is a cross-sectional view illustrating the operation of removing the coupling member 28 from the main body drive shaft 101. FIG. [Figure 21] FIG. 10 is a cross-sectional perspective view of a coupling member 28 of another embodiment according to the first embodiment. [Figure 22] FIG. 10 is a cross-sectional perspective view of a coupling member 228 according to a second embodiment. [Figure 23] FIG. 10 is a perspective view of a coupling member 228 according to a second embodiment. [Figure 24] FIG. 10 is a view of a coupling member 228 according to a second embodiment as viewed from the inside in the Z direction. [Figure 25] 10 is a cross-sectional view for explaining the mounting operation of the coupling member 228 to the main body drive shaft 101 according to the second embodiment. FIG. [Figure 26] FIG. 10 is a view of a coupling member 228 according to a second embodiment as viewed from the outside in the Z direction. [Figure 27] FIG. 10 is an explanatory cross-sectional view showing a state in which a coupling member 228 according to a second embodiment is molded in a mold. [Figure 28] 10 is a cross-sectional view of the coupling member 328 and the main body drive shaft 101 cut along the rotation axis. [Figure 29] 10 is an explanatory cross-sectional view illustrating deformation of a base portion and an engaging portion of a coupling member according to a fourth embodiment, the coupling member not including the coupling member being cut along a rotation center line (rotation axis). FIG. [Figure 30] FIG. 10 is a view of a coupling member 428 according to a fourth embodiment, viewed from the outside in the Z direction. [Figure 31] 10 is a view of a flange member 470 according to a fourth embodiment as viewed from the outside in the Z direction. FIG. [Figure 32] FIG. 10 is a cross-sectional view of a coupling member 428 according to a fourth embodiment, cut along the rotation center line (rotation axis line). [Figure 33] 10 is a view of a flange member 470 according to a fourth embodiment as viewed from the inside in the Z direction. FIG. [Figure 34] 10 is a view of a backup member 434 according to the fourth embodiment as viewed from the outside in the Z direction. FIG. [Figure 35] 10 is a cross-sectional view of a coupling member 428 and a main body drive shaft 101 according to a fourth embodiment, cut along the rotation center line (rotation axis). FIG. [Figure 36] FIG. 10 is a perspective view illustrating the assembly of an alignment member 434 to a flange member 470 according to the fourth embodiment. [Figure 37] FIG. 10 is a cross-sectional view of the main body drive shaft 101 and the coupling member 428 according to the fourth embodiment, taken in a direction perpendicular to the rotation axis and at a position passing through a driving force receiving surface 473a. [Figure 38] FIG. 10 is a cross-sectional view of a coupling member 428 and a main body drive shaft 101 of another embodiment according to the fourth embodiment, cut along the rotation center line (rotation axis). [Figure 39] FIG. 10 is a cross-sectional perspective view of a coupling member 528 according to a fifth embodiment. [Figure 40]10 is a cross-sectional view of a coupling member 528 according to a fifth embodiment, taken in a direction perpendicular to the rotation axis at a position passing through a drive transmission part 573. FIG. [Figure 41] 10 is a cross-sectional view of a coupling member 528 and a main body drive shaft 101 according to a fifth embodiment, taken in a direction perpendicular to the rotation axis at a position passing through a drive transmission part 573. FIG. [Figure 42] The configuration of the mold used when molding the flange member 570 according to the fifth embodiment will be described. [Figure 43] FIG. 10 is a perspective view of an aligning member 533 according to the fifth embodiment. [Figure 44] 10 is a view of an aligning member 533 according to the fifth embodiment as viewed from the outside in the Z direction. FIG. [Figure 45] FIG. 10 is a cross-sectional view of a coupling member 528 according to a fifth embodiment. [Figure 46] 10 is a view of a flange member 570 according to the fifth embodiment as viewed from the outside in the Z direction. FIG. [Figure 47] 10A and 10B are diagrams illustrating the assembly of a coupling member 528 according to the fifth embodiment. [Figure 48] 13 is a view of an aligning member 533 according to the fifth embodiment as viewed from the inside in the Z direction. FIG. [Figure 49] 13 is a cross-sectional view for explaining the mounting operation of the coupling member 528 to the main body drive shaft 101 according to the fifth embodiment. FIG. [Figure 50] 13 is a cross-sectional view for explaining the mounting operation of the coupling member 528 to the main body drive shaft 101 according to the fifth embodiment. FIG. [Figure 51] 10 is a cross-sectional view illustrating the transmission of drive power from a main body drive shaft 101 to a coupling member 528 according to the fifth embodiment. FIG. [Figure 52] 10 is a view of a flange member 570 according to a fifth embodiment as viewed from the inside in the Z direction. FIG. [Figure 53] 10 is a cross-sectional view illustrating the transmission of drive power from a main body drive shaft 101 to a coupling member 528 according to the fifth embodiment. FIG. [Figure 54] 10 is a cross-sectional view illustrating a state in which the positions of the main body drive shaft 101 and the coupling member 528 according to the fifth embodiment are misaligned due to component tolerances. FIG. [Figure 55]13 is a cross-sectional view illustrating the operation of removing a coupling member 528 from a main body drive shaft 101 according to the fifth embodiment. FIG. [Figure 56] 10 is a cross-sectional view illustrating drive transmission when a winding portion 574b of a base portion 574 of a coupling member 528 according to the fifth embodiment has a diameter larger than that of a shaft portion 101f of a main body drive shaft 101. FIG. [Figure 57] 10 is a cross-sectional view illustrating drive transmission when a winding portion 574b of a base portion 574 of a coupling member 528 according to the fifth embodiment has a diameter smaller than that of a shaft portion 101f of a main body drive shaft 101. FIG. [Figure 58] FIG. 13 is a cross-sectional view of a coupling member 628 according to a sixth embodiment. [Figure 59] FIG. 10 is a cross-sectional view of a flange member 670 according to a sixth embodiment. [Figure 60] 13 is a view of a flange member 670 according to a sixth embodiment as viewed from the outside in the Z direction. FIG. [Figure 61] 13 is an explanatory cross-sectional view showing the positional relationship in the Z direction of each component of the cleaning unit according to the sixth embodiment. [Figure 62] 10 is a cross-sectional view for explaining the mold configuration of a flange member 670 according to Example 6. FIG. [Figure 63] FIG. 13 is a perspective view of an aligning member 633 according to a sixth embodiment. [Figure 64] 13 is a cross-sectional view illustrating the operation of attaching a coupling member 628 to a main body drive shaft 101 according to the sixth embodiment. FIG. [Figure 65] 13 is a cross-sectional view illustrating the operation of attaching a coupling member 628 to a main body drive shaft 101 according to the sixth embodiment. FIG. [Figure 66] 13 is a view of a flange member 670 according to a sixth embodiment as viewed from the inside in the Z direction. FIG. [Figure 67] FIG. 13 is a cross-sectional view illustrating the transmission of drive power from a main body drive shaft to a coupling member according to a sixth embodiment. [Figure 68] 13 is a cross-sectional view illustrating the operation of removing a coupling member 628 from a main body drive shaft 101 according to the sixth embodiment. FIG. [Figure 69]This is a cross-sectional view illustrating a state in which, when a flange member is made using a material with large creep deformation, the drive transmission from the main body drive shaft 101 to the coupling member 3628 becomes unstable after long-term storage in a state in which the phases of the engagement portion and the main body drive transmission groove are not aligned. [Figure 70] 13 is a cross-sectional view illustrating the configuration of a mold for inserting a metal plate 635 into a flange member 670 according to the sixth embodiment. FIG. [Figure 71] 13 is a view of a flange member 670 according to a sixth embodiment as viewed from the outside in the Z direction. FIG. [Figure 72] FIG. 10 is a cross-sectional view of a flange member 670 according to a sixth embodiment. [Figure 73] FIG. 13 is a cross-sectional perspective view of a flange member 670 according to a sixth embodiment. [Figure 74] FIG. 10 is a partial cross-sectional view of a flange member 670 according to a sixth embodiment, taken along a straight portion notch 674g. [Figure 75] FIG. 10 is a partial cross-sectional view of a flange member 670 according to a sixth embodiment, taken along a notch 674h in a winding portion. [Figure 76] FIG. 13 is a cross-sectional view of a coupling member 728 according to a seventh embodiment. [Figure 77A] FIG. 13 is a cross-sectional view of a coupling member 828 according to an eighth embodiment. [Figure 77B] FIG. 13 is a cross-sectional view of a coupling member 828 and a main body drive shaft 101 according to an eighth embodiment, taken in a direction perpendicular to the rotation axis and at a position passing through a driving force receiving surface 873a. [Figure 78] FIG. 13 is a cross-sectional view illustrating deformation of the base and the engaging portion of a coupling member according to an eighth embodiment, the coupling member not using the coupling member being cut along the rotation center line (rotation axis). [Figure 79] FIG. 13 is a cross-sectional view of a coupling member 828 according to an eighth embodiment. [Figure 80] FIG. 13 is a cross-sectional view of a coupling member 928 according to a ninth embodiment. [Figure 81] FIG. 13 is a cross-sectional view of another embodiment of a coupling member 928 according to Example 9. [Figure 82]FIG. 13 is a cross-sectional view of another embodiment of a coupling member 928 according to Example 9. [Figure 83] FIG. 20 is a view of a coupling member 1028 according to a tenth embodiment, viewed from the outside in the Z direction. [Figure 84] FIG. 20 is a cross-sectional view of a coupling member 1028 and a main body drive shaft 101 according to a tenth embodiment, taken in a direction perpendicular to the rotation axis and at a position passing through a driving force receiving surface 1073a. [Figure 85] FIG. 20 is a cross-sectional view of a coupling member 1028 according to a tenth embodiment. [Figure 86] FIG. 20 is a cross-sectional view of a modified example of a coupling member 1028 according to a tenth embodiment. [Figure 87A] FIG. 20 is a view of a coupling member 1128 according to an eleventh embodiment, seen from the outside in the Z direction. [Figure 87B] FIG. 20 is a cross-sectional perspective view of a coupling member 1128 according to an eleventh embodiment. [Figure 88] FIG. 20 is a cross-sectional view of a coupling member 1128 according to an eleventh embodiment. [Figure 89] FIG. 20 is a cross-sectional perspective view of a coupling member 1128 according to an eleventh embodiment. [Figure 90] FIG. 23 is a cross-sectional view of a modified example of a coupling member 1128 according to the eleventh embodiment. [Figure 91] FIG. 20 is a view of a flange member 1270 according to a twelfth embodiment, viewed from the outside in the Z direction. [Figure 92] FIG. 20 is a cross-sectional view of a coupling member 1228 according to a twelfth embodiment. [Figure 93] FIG. 23 is a cross-sectional view of a modified example of a flange member 1270 according to the twelfth embodiment. [Figure 94] FIG. 20 is a view of a flange member 1370 according to a thirteenth embodiment, viewed from the outside in the Z direction. [Figure 95] FIG. 20 is a cross-sectional view of a coupling member 1328 and a main body drive shaft 101 according to a thirteenth embodiment, taken in a direction perpendicular to the rotation axis and at a position passing through a driving force receiving surface 1373a. [Figure 96] FIG. 20 is a perspective view of an alignment member 1333 according to a thirteenth embodiment. [Figure 97] FIG. 20 is a cross-sectional view of a coupling member 1328 according to a thirteenth embodiment. [Figure 98] FIG. 23 is a cross-sectional view of a modified example of a flange member 1370 according to the thirteenth embodiment. [Figure 99] FIG. 20 is a perspective view of an alignment member 1633 according to a fourteenth embodiment. [Figure 100] FIG. 20 is a view of an aligning member 1633 according to Example 14, viewed from the outside in the Z direction. [Figure 101] FIG. 16 is a perspective view of such a flange member 1670 according to the fourteenth embodiment. [Figure 102] FIG. 20 is a view of a flange member 1670 according to a fourteenth embodiment, viewed from the outside in the Z direction. [Figure 103] FIG. 20 is a cross-sectional view of a flange member 1670 according to a fourteenth embodiment. [Figure 104] FIG. 20 is a view of a flange member 1670 according to a fourteenth embodiment, viewed from the rear side in the Z direction. [Figure 105] 16 is an explanatory diagram of an assembly procedure for a coupling member 1628 according to a fourteenth embodiment. FIG. [Figure 106] FIG. 20 is a cross-sectional view of a coupling member 1628 according to a fourteenth embodiment. [Figure 107] FIG. 16 is an explanatory diagram of the stress acting on a base not using the base configuration according to Example 15. [Figure 108] FIG. 23 is an explanatory diagram of a base 1774 of a flange member according to a fifteenth embodiment. [Figure 109] FIG. 23 is an explanatory diagram of a modified example of a base portion 1774 of a flange member according to the fifteenth embodiment. [Figure 110] FIG. 20 is an explanatory diagram of a base 1874 of a flange member according to a sixteenth embodiment. [Figure 111] FIG. 20 is an explanatory diagram of a base 1974 of a flange member according to a seventeenth embodiment. [Figure 112] FIG. 23 is a cross-sectional perspective view of a flange member 2170 and an engaging member 2173 according to a nineteenth embodiment. [Figure 113] FIG. 23 is a cross-sectional view of a coupling member 2128 according to a nineteenth embodiment. [Figure 114]FIG. 23 is a view of a coupling member 2128 and a main body drive shaft 2101 according to the nineteenth embodiment, as viewed from the rear side in the Z direction. [Figure 115] 23 is a cross-sectional view for explaining the operation of attaching a coupling member 2128 to a main body drive shaft 2110 according to the nineteenth embodiment. FIG. [Figure 116] FIG. 22 is a view of a coupling member 2228 and a main body drive shaft 2101 according to a twentieth embodiment, as viewed from the rear side in the Z direction. [Figure 117] FIG. 23 is an explanatory diagram of drive transmission from a main body drive shaft to a coupling member that does not use the configuration of the coupling member according to Example 21. [Figure 118] FIG. 23 is a cross-sectional view of a coupling member 2328 according to a twenty-first embodiment. [Figure 119] FIG. 23 is a cross-sectional view of a coupling member 2328 and a main body drive shaft 2410 according to a 21st embodiment. [Figure 120] FIG. 22 is a perspective view of a main body drive shaft 2210 according to Examples 19 to 21. [Figure 121] FIG. 21 is a perspective view of a cartridge 7 according to Examples 19 to 21. [Figure 122] FIG. 22 is a cross-sectional view of a coupling member 2438 according to a twenty-second embodiment. [Figure 123] FIG. 22 is a cross-sectional perspective view of a coupling member 2428 according to a twenty-second embodiment. [Figure 124] FIG. 22 is a cross-sectional view of a coupling member 2428 according to a twenty-second embodiment, taken in a direction perpendicular to the rotation axis of the coupling member 2428, at a position passing through a straight portion 2474p of a base portion 2474. [Figure 125] FIG. 22 is a cross-sectional view of a coupling member 2428 and a main body drive shaft 101 according to a 22nd embodiment, taken in a direction perpendicular to the rotation axis and at a position passing through a driving force receiving surface 2473a. [Figure 126] FIG. 22 is a perspective view of an adjusting member 2433 according to a twenty-second embodiment. [Figure 127] 22A and 22B are cross-sectional views for explaining the mounting operation of a coupling member 2428 to a main body drive shaft 101 according to the twenty-second embodiment. [Figure 128]22A and 22B are cross-sectional views for explaining the mounting operation of a coupling member 2428 to a main body drive shaft 101 according to the twenty-second embodiment. [Figure 129] FIG. 22 is a view of a flange member 2470 according to a twenty-second embodiment, viewed from the inside in the Z direction. [Figure 130] FIG. 22 is a cross-sectional view of a coupling member 2438 according to a twenty-second embodiment. [Figure 131] FIG. 22 is a perspective view illustrating the assembly of an alignment member 2433 to a flange member 2470 according to the twenty-second embodiment. [Figure 132] FIG. 23 is a cross-sectional perspective view of a coupling member 2528 according to a twenty-third embodiment. [Figure 133] 23 is a cross-sectional view of a coupling member 2528 according to Example 23, taken in a direction perpendicular to the rotation axis of the coupling member 2528, at a position passing through a straight portion 2574p of a base portion 2574. FIG. [Figure 134] FIG. 23 is a cross-sectional view of a coupling member 2538 according to a twenty-third embodiment. [Figure 135] FIG. 26 is a perspective view of a cylindrical inner member 2640 according to a twenty-fourth embodiment. [Figure 136] FIG. 26 is a cross-sectional view of a cylindrical inner member 2640 according to a twenty-fourth embodiment. [Figure 137] FIG. 26 is a cross-sectional view of a coupling member 2628 according to a twenty-fourth embodiment, taken in a direction perpendicular to the rotation axis of the coupling member 2628, at a position passing through a straight portion 2674p of a base portion 2674. [Figure 138] FIG. 26 is a perspective view illustrating the assembly of a cylindrical inner member 2640 to a flange member 2670 according to the twenty-fourth embodiment. [Figure 139] FIG. 26 is a cross-sectional view of a coupling member 2628 according to a twenty-fourth embodiment. [Figure 140] FIG. 26 is a cross-sectional perspective view of a coupling member 2628 according to a twenty-fourth embodiment. [Figure 141] FIG. 26 is an explanatory cross-sectional view illustrating the movement of a cylindrical inner member 2640 relative to a flange member 2670 according to the twenty-fourth embodiment. [Figure 142] FIG. 25 is a schematic cross-sectional view of an image forming apparatus 4100A according to a twenty-fifth embodiment. [Figure 143]FIG. 25 is an external perspective view of a drum cartridge 4013 according to a twenty-fifth embodiment. [Figure 144] FIG. 25 is a cross-sectional view of a drum cartridge 4013 according to a twenty-fifth embodiment. [Figure 145] FIG. 25 is a perspective view of the appearance of a developing cartridge 4004 according to a twenty-fifth embodiment. [Figure 146] FIG. 25 is a cross-sectional view of a developing cartridge 4004 according to a twenty-fifth embodiment. [Figure 147] FIG. 25 is an outline view of a main body drive shaft 4101 according to a twenty-fifth embodiment. [Figure 148] FIG. 21 is a cross-sectional view taken along the rotation axis (rotation axis line) of a main body drive shaft 4101 attached to the image forming apparatus main body according to Example 25. [Figure 149] FIG. 25 is a cross-sectional view of a coupling member 4028 according to a twenty-fifth embodiment, taken along a direction perpendicular to the rotation axis of the coupling member 4028 and at a position passing through a base 4074. [Figure 150] FIG. 25 is a view of a cylinder member 4070 according to a twenty-fifth embodiment, viewed from the outside in the Z direction. [Figure 151] FIG. 25 is a perspective view of an alignment member 4033 according to a twenty-fifth embodiment. [Figure 152] 25A and 25B are diagrams illustrating the assembly of a coupling member 4028 according to a twenty-fifth embodiment. [Figure 153] FIG. 25 is a cross-sectional view of a developing cartridge 4004 according to a twenty-fifth embodiment. [Fig. 154] FIG. 25 is a perspective view for explaining the mounting of a developing cartridge 4004 to an image forming apparatus main body 4100A according to a twenty-fifth embodiment. [Figure 155] 25A and 25B are cross-sectional views for explaining the mounting operation of the developing cartridge 4004 to the image forming apparatus main body 4100A according to the twenty-fifth embodiment. [Figure 156] FIG. 25 is a cross-sectional view illustrating the operation of attaching a coupling member 4028 to a main body drive shaft 4101 according to the twenty-fifth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] The image forming apparatus and process cartridge of this embodiment will be described below with reference to the drawings. Note that the image forming apparatus is one that forms an image on a recording medium using, for example, an electrophotographic image forming process. Examples include electrophotographic copiers, electrophotographic printers (e.g., LED printers, laser beam printers, etc.), and electrophotographic facsimile machines. Furthermore, the term "cartridge" refers to an item that is detachably attached to the image forming apparatus main body. Among cartridges, those that integrate a photosensitive member and process means that act on the photosensitive member are called process cartridges.

[0010] The photosensitive drum and the coupling member are integrated into one unit called a drum unit.

[0011] In the following examples, a full-color image forming apparatus in which four process cartridges can be detachably attached is illustrated. However, the number of process cartridges to be attached to the image forming apparatus is not limited to this. Similarly, unless otherwise specified, the materials, arrangement, dimensions, and other numerical values ​​of each configuration disclosed in the examples are not limited. Furthermore, unless otherwise specified, "upper" refers to the direction of gravity when the image forming apparatus is installed.

[0012] Example 1 [Outline of Electrophotographic Image Forming Apparatus] First, the overall configuration of an embodiment of an electrophotographic image forming apparatus (image forming apparatus) according to the present invention will be described with reference to FIG.

[0013] FIG. 1 is a schematic cross-sectional view of an image forming apparatus 100 according to this embodiment.

[0014] 1, image forming apparatus 100 has a plurality of image forming units, namely, first, second, third, and fourth image forming units SY, SM, SC, and SK, for forming images of yellow (Y), magenta (M), cyan (C), and black (K), respectively. In this embodiment, the first to fourth image forming units SY, SM, SC, and SK are arranged in a line in the approximately horizontal direction.

[0015] In this embodiment, the configuration and operation of the process cartridges 7 (7Y, 7M, 7C, 7K) are substantially the same except for the colors of the images they form. Therefore, unless a distinction is particularly required, the Y, M, C, and K will be omitted and a general description will be given.

[0016] In this embodiment, the image forming apparatus 100 has, as a plurality of image carriers, cylinders (hereinafter referred to as photosensitive drums) 1 each having four photosensitive layers arranged side by side in a direction slightly inclined relative to the vertical direction. A scanner unit (exposure device) 3 is disposed below the process cartridge 7 in the direction of gravity. In addition, around the photosensitive drum 1, a charging roller 2 and the like are disposed as process means (process device, process member) that act on the photosensitive layers.

[0017] The charging roller 2 is a charging means (charging device, charging member) that uniformly charges the surface of the photosensitive drum 1. The scanner unit (exposure device) 3 is an exposure means (exposure device, exposure member) that irradiates a laser based on image information to form an electrostatic image (electrostatic latent image) on the photosensitive drum 1. Around the photosensitive drum 1, a developing device (hereinafter referred to as a developing unit) 4 and a cleaning blade 6 that serves as cleaning means (cleaning device, cleaning member) are arranged.

[0018] Furthermore, facing the four photosensitive drums 1, an intermediate transfer belt 5 is arranged as an intermediate transfer member for transferring the toner images on the photosensitive drums 1 onto a recording material (sheet, recording medium) 12.

[0019] The developing unit 4 of this embodiment uses a non-magnetic one-component developer (hereinafter, toner) as the developer, and employs a contact development method in which a developing roller 17 as a developer carrier is brought into contact with the photosensitive drum 1.

[0020] In the above-described configuration, the toner image formed on the photosensitive drum 1 is transferred onto a sheet (paper) 12, and the toner image transferred onto the sheet is fixed. Furthermore, as process means acting on the photosensitive drum 1, the process cartridge is equipped with a charging roller 2 that charges the photosensitive drum 1, and a cleaning blade 6 that cleans toner that remains on the photosensitive drum 1 without being transferred. Transfer residual toner that remains on the photosensitive drum 1 without being transferred onto the sheet 12 is collected by the cleaning blade 6. Transfer residual toner collected by the cleaning blade 6 is collected into a removed developer storage compartment (hereinafter referred to as a waste toner storage compartment) 14a through an opening 14b. The waste toner storage compartment 14a and the cleaning blade 6 are integrated to form a cleaning unit (photosensitive unit, image carrier unit) 13.

[0021] Furthermore, the developing unit 4 and the cleaning unit 13 are integrated into a unit (cartridge) to constitute the process cartridge 7. The image forming apparatus 100 is provided with guides (positioning means) such as mounting guides and positioning members (not shown) on the main body frame. The process cartridge 7 is guided by the aforementioned guides and is configured to be detachable from the image forming apparatus main body (electrophotographic image forming apparatus main body) 100A.

[0022] The process cartridges 7 for the respective colors contain toner of yellow (Y), magenta (M), cyan (C), and black (K), respectively.

[0023] The intermediate transfer belt 5 contacts the photosensitive drum 1 provided in each process cartridge and rotates (moves) in the direction of arrow B in FIG. 1. The intermediate transfer belt 5 is stretched over a plurality of support members (a drive roller 51, a secondary transfer opposing roller 52, and a driven roller 53). Four primary transfer rollers 8 serving as primary transfer means are arranged side by side on the inner circumferential surface of the intermediate transfer belt 5 so as to face the respective photosensitive drums 1. Furthermore, a secondary transfer roller 9 serving as secondary transfer means is arranged on the outer circumferential surface of the intermediate transfer belt 5 at a position facing the secondary transfer opposing roller 52.

[0024] When forming an image, first, the surface of the photosensitive drum 1 is uniformly charged by the charging roller 2. Next, the charged surface of the photosensitive drum 1 is scanned and exposed by a laser beam corresponding to image information emitted from the scanner unit 3. As a result, an electrostatic latent image corresponding to the image information is formed on the photosensitive drum 1. The electrostatic latent image formed on the photosensitive drum 1 is developed into a toner image by the developing unit 4.

[0025] The photosensitive drum is a rotating body (image carrier) that rotates while carrying an image (developer image, toner image) formed with a developer (toner) on its surface.

[0026] The toner image formed on the photosensitive drum 1 is transferred (primary transfer) onto the intermediate transfer belt 5 by the action of the primary transfer roller 8.

[0027] For example, when a full-color image is formed, the above-described process is performed sequentially in four process cartridges 7 (7Y, 7M, 7C, 7K). Then, the toner images of each color formed on the photosensitive drum 1 of each process cartridge 7 are sequentially transferred (primary transfer) so as to be superimposed on the intermediate transfer belt 5. Thereafter, in synchronization with the movement of the intermediate transfer belt 5, the recording material 12 is transported to the secondary transfer portion. Then, the four-color toner images on the intermediate transfer belt 5 are transferred all at once onto the recording material 12 transported to the secondary transfer portion formed by the intermediate transfer belt 5 and the secondary transfer roller 9.

[0028] The recording material 12 onto which the toner image has been transferred is conveyed to a fixing device 10 serving as a fixing means. The fixing device 10 applies heat and pressure to the recording material 12, thereby fixing the toner image to the recording material 12. Furthermore, primary transfer residual toner remaining on the photosensitive drum 1 after the primary transfer step is removed by a cleaning blade 6 and collected as waste toner. Furthermore, secondary transfer residual toner remaining on the intermediate transfer belt 5 after the secondary transfer step is removed by an intermediate transfer belt cleaning device 11.

[0029] Note that the image forming apparatus 100 can also form a single-color or multi-color image using a desired single or several (but not all) image forming units.

[0030] [Process cartridge overview] Next, the process cartridge 7 (cartridge 7) to be mounted in the image forming apparatus main body 100A of this embodiment will be described in outline with reference to FIGS. 2, 3 and 4. FIG.

[0031] The cartridge 7a containing yellow toner, the cartridge 7b containing magenta toner, the cartridge 7c containing cyan toner, and the cartridge 7d containing black toner all have the same configuration. Therefore, in the following description, the cartridges 7a, 7b, 7c, and 7d will be collectively referred to as cartridge 7. The components of each cartridge will also be collectively referred to.

[0032] Fig. 2 is an external perspective view of the process cartridge 7. Here, as shown in Fig. 2, the direction of the rotation axis of the photosensitive drum 1 is the Z direction (arrows Z1 and Z2), the horizontal direction in Fig. 1 is the X direction (arrows X1 and X2), and the vertical direction in Fig. 1 is the Y direction (arrows Y1 and Y2).

[0033] FIG. 3 is a schematic cross-sectional view of the process cartridge 7, as viewed along the Z direction, when it is mounted in the image forming apparatus 100 and in a state (posture) in which the photosensitive drum 1 and the developing roller 17 are in contact with each other.

[0034] The process cartridge 7 is made up of two units: a cleaning unit 13 which combines the photosensitive drum 1, the charging roller 2, and the cleaning blade 6; and a developing unit 4 which has developing members such as a developing roller 17.

[0035] The developing unit 4 has a developing frame 18 that supports various elements within the developing unit 4. The developing unit 4 is provided with a developing roller 17 as a developer carrier that contacts the photosensitive drum 1 and rotates in the direction of arrow D (counterclockwise) in the drawing. The developing roller 17 is rotatably supported by the developing frame 18 at both ends in its longitudinal direction (direction of the rotation axis) via developing bearings 19 (19R, 19L). Here, the developing bearings 19 (19R, 19L) are attached to both sides of the developing frame 18, respectively.

[0036] The developing unit 4 also has a developer storage chamber (hereinafter referred to as a toner storage chamber) 18a and a developing chamber 18b in which a developing roller 17 is disposed.

[0037] In the developing chamber 18b, there are disposed a toner supply roller 20 as a developer supply member that contacts the developing roller 17 and rotates in the direction of arrow E, and a developing blade 21 as a developer regulating member that regulates the toner layer on the developing roller 17. The developing blade 21 is fixed and integrated with a fixed member 22 by welding or the like.

[0038] The toner storage chamber 18a of the developing frame 18 is provided with an agitating member 23 for agitating the stored toner and transporting the toner to the toner supply roller 20.

[0039] The developing unit 4 is coupled to the cleaning unit 13 and rotatable about a fitting shaft 24 (24R, 24L) that fits into holes 19Ra and 19La provided in the bearing members 19R and 19L. The developing unit 4 is also biased by a pressure spring 25 (25R, 25L) in a direction in which the developing roller 17 comes into contact with the photosensitive drum 1. Therefore, during image formation by the process cartridge 7, the developing unit 4 turns (rotates) about the fitting shaft 24 in the direction of arrow F, and the photosensitive drum 1 and the developing roller 17 come into contact with each other.

[0040] The cleaning unit 13 has a cleaning frame 14 as a frame that supports various elements within the cleaning unit 13 .

[0041] 4 is a cross-sectional view taken along an imaginary plane including the center of rotation of the photosensitive drum 1 of the process cartridge 7. The side (Z1 direction side) on which the coupling member 28 receives a driving force from the image forming apparatus main body is called the driving side (rear side) of the process cartridge 7. The side opposite the driving side (Z2 direction side) is called the non-driving side (front side) of the process cartridge 7.

[0042] At the end opposite the coupling member 28 (the end on the non-drive side of the process cartridge), there is an electrode (electrode portion) that comes into contact with the inner surface of the photosensitive drum 1, and this electrode acts as an earth by coming into contact with the main body of the image forming apparatus.

[0043] A coupling member 28 is attached to one end of the photosensitive drum 1, and a non-drive-side flange member 29 is attached to the other end of the photosensitive drum 1, to form a photosensitive drum unit 30. The photosensitive drum unit 30 receives driving force from a main body drive shaft 101 provided in the image forming apparatus main body 100A via the coupling member 28 (the driving force is transmitted from the main body drive shaft 101). The coupling member 28 is configured to be connectable to and detachable from the main body drive shaft 101. The coupling member 28 is also a flange member (drive-side flange member) attached to the drive-side end of the photosensitive drum 1.

[0044] As shown in FIG. 4, the Z1 side of the coupling member 28 has a cylindrical shape (cylindrical portion 71). The cylindrical portion 71 protrudes further toward the Z1 side (axially outward) than the end of the photosensitive drum 1. The outer peripheral portion of this cylindrical portion 71 is an outer peripheral surface 71a. This outer peripheral surface 71a is provided with a notched shape 71d for forming a base portion 74, which will be described later. The portion of the cylindrical portion 71 on the Z1 side of the notched shape 71d is a bearing portion 71c. The bearing portion 71c is rotatably supported in a bearing portion provided in the drum unit bearing member 39R. In other words, the photosensitive drum unit 30 becomes rotatable when the bearing portion 71c is supported by the bearing portion of the drum unit bearing member 39R.

[0045] Similarly, the non-drive-side flange member 29 provided on the non-drive side of the photosensitive drum unit 30 is rotatably supported by the drum unit bearing member 39L. The non-drive-side flange member 29 has a cylindrical portion (cylindrical portion) that protrudes from the end of the photosensitive drum 1, and the outer peripheral surface 29a of this cylindrical portion is rotatably supported by the drum unit bearing member 39L.

[0046] The drum unit bearing member 39R is disposed on the drive side of the process cartridge 7, and the drum unit bearing member 39L is disposed on the non-drive side of the process cartridge 7.

[0047] When the process cartridge 7 is mounted in the apparatus main body 100A, as shown in Fig. 4, the drum unit bearing member 39R abuts against a rear cartridge positioning portion 108 provided in the image forming apparatus main body 100A. Also, the drum unit bearing member 39L abuts against a front cartridge positioning portion 110 of the image forming apparatus main body 100A. This positions the cartridge 7 in the image forming apparatus 100A.

[0048] In the Z direction in this embodiment, the position where the drum unit bearing member 39R supports the bearing portion 71c is located close to the position where the drum unit bearing member 39R is positioned by the rear cartridge positioning portion 108. This makes it possible to prevent the coupling member 28 from tilting when the process cartridge 7 is attached to the apparatus main body 100A.

[0049] The borne portion 71c is positioned so that the position where the bearing member 39R supports the borne portion 71c is close to the position where the bearing member 39R is positioned relative to the rear cartridge positioning portion 108. In other words, the borne portion 71c is positioned on the tip side (Z1 direction side) of the outer circumferential surface 71a of the cylindrical portion 71 provided on the coupling member 28.

[0050] Similarly, in the Z direction, the portion where the drum unit bearing member 39L rotatably supports the non-drive-side flange member 29 is located close to the position where the drum unit bearing member 39L is positioned in the front cartridge positioning portion 110. This prevents the non-drive-side flange member 29 from tilting.

[0051] Drum unit bearing members 39R and 39L are attached to both sides of the cleaning frame 14, respectively, and support the photosensitive drum unit 30. As a result, the photosensitive drum unit 30 is rotatably supported by the cleaning frame 14.

[0052] The cleaning frame 14 also has attached thereto the charging roller 2 and cleaning blade 6, which are arranged so as to come into contact with the surface of the photosensitive drum 1. The cleaning frame 14 also has attached thereto charging roller bearings 15 (15R, 15L). The charging roller bearings 15 are bearings for supporting the shaft of the charging roller 2.

[0053] Here, the charge roller bearings 15 (15R, 15L) are attached so as to be movable in the direction of arrow C shown in FIG. 3. The rotation shaft 2a of the charge roller 2 is rotatably attached to the charge roller bearings 15 (15R, 15L). The charge roller bearing 15 is urged toward the photosensitive drum 1 by a pressure spring 16 serving as urging means. As a result, the charge roller 2 comes into contact with the photosensitive drum 1 and is rotated by the photosensitive drum 1.

[0054] The cleaning frame 14 is provided with a cleaning blade 6 as cleaning means for removing toner remaining on the surface of the photosensitive drum 1. The cleaning blade 6 is an integrated unit consisting of a blade-shaped rubber (elastic member) 6a that comes into contact with the photosensitive drum 1 to remove toner from the photosensitive drum 1, and a supporting metal plate 6b that supports it. In this embodiment, the supporting metal plate 6b is fixed to the cleaning frame 14 with screws.

[0055] As described above, the cleaning frame 14 has an opening 14b for collecting the residual toner collected by the cleaning blade 6. A blowout prevention sheet 26 is provided in the opening 14b, which comes into contact with the photosensitive drum 1 and seals the gap between the photosensitive drum 1 and the opening 14b, thereby preventing toner from leaking upward from the opening 14b.

[0056] By adopting a configuration in which elements related to image formation are integrated into a cartridge that is detachable from the apparatus main body in this way, ease of maintenance is improved. In other words, a user can easily perform maintenance on the apparatus by simply attaching and detaching the process cartridge to and from the apparatus main body. Therefore, it is possible to provide an apparatus in which maintenance can be easily performed not only by a service technician but also by the user.

[0057] [Main body drive shaft configuration] The configuration of the main body drive shaft 101 will be described with reference to FIGS. 5, 6, 7, 8 and 9. FIG.

[0058] FIG. 5 is an outline drawing of the main body drive shaft.

[0059] FIG. 6 is a cross-sectional view taken along the rotation axis (rotation axis line) of the main body drive shaft 101 in a state where it is attached to the main body of the image forming apparatus.

[0060] FIG. 7 is a cross-sectional view of the coupling 28 and the main body drive shaft 101 cut along the rotation axis (rotation axis line).

[0061] FIG. 8 is a cross-sectional view of the coupling member 28 and the main body drive shaft 101 cut in a direction perpendicular to the rotation axis.

[0062] FIG. 9 is a cross-sectional view of the coupling 28 and the main body drive shaft 101 cut along the rotation axis.

[0063] As shown in FIG. 5, the main body drive shaft 101 has a gear portion 101e, a shaft portion 101f, a rough guide portion 101g, and a bearing portion 101d.

[0064] The image forming apparatus main body 100A is provided with a motor (not shown) as a drive source. A gear portion 101e receives rotational drive force from this motor, causing the main body drive shaft 101 to rotate. The main body drive shaft 101 also has a rotatable, protruding shaft portion 101f that protrudes further toward the cartridge 7 than the gear portion 101e along its rotation axis. The rotational drive force received from the motor is transmitted to the cartridge 7 via a groove-shaped drive transmission groove 101a (recessed portion, drive transfer portion) provided in the shaft portion 101f. The shaft portion 101f also has a hemispherical shape 101c at its tip.

[0065] This main body drive transmission groove 101a has a shape that allows a part of the engaging portion 73, which will be described later, to enter. Specifically, it is provided with a main body drive transmission surface 101b that comes into contact with a driving force receiving surface (driving force receiving portion) 73a of the coupling member 28 and transmits the driving force.

[0066] 5, the main body drive transmission surface 101b is not flat, but has a shape twisted around the center of the rotation axis of the main body drive shaft 101. The twisting direction is such that the Z1 direction side of the main body drive shaft 101 is located upstream of the Z2 direction side in the rotation direction of the main body drive shaft 101. In this embodiment, the amount of twisting along the rotation axis direction of the cylinder of the engagement portion 73 is about 1° per 1 mm. The reason for the twisted shape of the main body drive transmission surface 101b will be described later.

[0067] Furthermore, a main body side removal taper 101i is provided on the surface of the main body drive transmission groove 101a on the Z2 direction side. The main body side removal taper 101i is a taper (inclined surface, inclined portion) that helps the engaging portion 73 to come out of the drive transmission groove 101a when the process cartridge 7 is removed from the apparatus main body 100A. Details will be described later.

[0068] Here, it is desirable that the main body drive transmission surface 101b and the drive force receiving surface (drive force receiving portion) 73a be in reliable contact when transmitting drive from the drive transmission groove 101a to the engagement portion 73. Therefore, to prevent surfaces other than the main body drive transmission surface 101b from contacting the engagement portion 73, the main body drive transmission groove 101a is configured to have gaps (G) with respect to the engagement portion 73 in the rotational axis direction, circumferential direction, and radial direction (see FIGS. 8 and 9).

[0069] The axial tip of the main body drive transmission groove 101a has a main body removal taper 101i as an inclined surface (inclined portion). In the axial direction of the main body drive shaft 101, the center 101h of the hemispherical shape 101c is located within the range of the main body drive transmission groove 101a (see FIG. 7). In other words, when the center 101h and the main body drive transmission groove 101a are projected onto the axis of the main body drive shaft 101, the projected area of ​​the center 101h is located within the projected area of ​​the main body drive transmission groove 101a on the axis.

[0070] The rough guide portion 101g is provided between the shaft portion 101f and the gear portion 101e in the axial direction (see FIG. 6). The rough guide portion 101g has a tapered shape at the tip on the shaft portion 101f side, and the outer diameter D6 of the rough guide portion 101g is smaller than the inner diameter D2 of the inner circumferential surface 71b of the cylindrical portion 71 of the coupling member 28 (described later), as shown in FIG. 7. Furthermore, the outer diameter D6 of the rough guide portion 101g is larger than the outer diameter D5 of the shaft portion 101f, as shown in FIG. 5. This allows the main assembly drive shaft 101 to be guided along the coupling member 28 so as to reduce axial misalignment between the center of rotation of the cylindrical portion 71 and the center of rotation of the shaft portion 101f when the cartridge 7 is inserted into the image forming apparatus main assembly 100A. Therefore, the rough guide portion 101g can be referred to as an insertion guide.

[0071] After the cartridge 7 has been completely mounted in the image forming apparatus main body 100A, the rough guide portion 101g is set to have a dimensional relationship such that it does not come into contact with the inner peripheral surface 71b.

[0072] 6, the bearing portion 101d is disposed on the opposite side of the rough guide portion 101g with the gear portion 101e in between. The bearing portion 101d is rotatably supported (axially supported) by a bearing member 102 provided in the image forming apparatus main body 100A.

[0073] 6, the main body drive shaft 101 is biased toward the cartridge 7 by a spring member 103 of the image forming apparatus main body 100A. However, the amount of movement (backlash) of the main body drive shaft 101 in the Z direction is about 1 mm, which is sufficiently smaller than the width in the Z direction of a driving force receiving surface 73a, which will be described later.

[0074] As described above, the main assembly drive transmission groove 101a is provided on the main assembly drive shaft 101, and the engaging portion 73 is provided on the coupling member 28, so that the drive is transmitted from the apparatus main assembly 100A to the cartridge 7 (drum unit 30).

[0075] As will be described in detail later, the engaging portion 73 is provided at the tip of the elastically deformable base portion 74. Therefore, the engaging portion 73 is configured to be movable at least radially outward when the cartridge 7 is attached to the apparatus main body 100A. As a result, as the cartridge 7 is inserted into the apparatus main body 100A, the engaging portion 73 enters the drive transmission groove 101a, allowing the engaging portion 73 to engage with the drive transmission groove 101a.

[0076] [Configuration of coupling components] Next, the coupling member 28 of this embodiment will be described in detail with reference to FIGS. 4, 10, 11, 12, 13, 14, and 15.

[0077] FIG. 10 is a perspective view of the coupling member 28.

[0078] FIG. 11 is a cross-sectional view of the coupling member 28 taken along a line perpendicular to the axis of rotation of the coupling member 28 and passing through the base 74. As shown in FIG.

[0079] FIG. 12 is a cross-sectional perspective view of the coupling member 28.

[0080] FIG. 13 is a cross-sectional view of the coupling member 28 taken along the rotation axis.

[0081] FIG. 14 is a cross-sectional view of the coupling member 28 and the main body drive shaft 101 cut in a direction perpendicular to the rotation axis at a position passing through the base 74.

[0082] FIG. 15 is a cross-sectional view of the coupling member 28 and the main body drive shaft 101 cut along the rotation axis.

[0083] 10 and 12, the coupling member 28 includes an attachment portion 72, a cylindrical portion 71, a flange portion 75, an engagement portion 73, a base portion 74, and an alignment portion 76. The attachment portion 72 is a portion for attachment to the photosensitive drum 1. The cylindrical portion 71 has a substantially cylindrical shape. As described above, the cylindrical portion 71 has a bearing portion 71c, which is rotatably supported by a bearing portion provided in the drum unit bearing member 39R.

[0084] The engaging portion 73 protrudes at least radially inward of the coupling member 28 to engage with the main body drive shaft 101. The engaging portion 73 has a driving force receiving surface 73a. The driving force receiving surface 73a is a driving force receiving portion that receives the driving force from the main body drive shaft 101 by coming into contact with the driving groove.

[0085] The base portion (deformation portion, extension portion) 74 is formed by a notch shape 71d provided in the cylindrical portion 71 of the coupling member 28. The notch shape 71d is an angular U-shape. The base portion 74 is deformable starting from a root portion 74a of the base portion 74, and movably supports the engaging portion 73. The engaging portion 73 is movable at least in the radial direction of the coupling member.

[0086] That is, the driving force receiving surface (driving force receiving portion) 73a is supported by the base portion (support portion base portion) 74 and the engaging portion (protruding portion) 73. The base portion 74 and the engaging portion 73 form a supporting portion for supporting the driving force receiving surface 73a. In this embodiment, the supporting portion extends substantially parallel to the axial direction of the coupling member 28.

[0087] As shown in FIG. 10, the mounting portion 72 has a press-fit portion 72d that is press-fitted into the inner diameter of the cylinder of the photosensitive drum 1, a crimping groove 72e, and a press-fit guide portion 72f that is provided on the inner side (Z2 direction side) of the press-fit portion 72d.

[0088] The press-fit portion 72d as a connecting portion is a portion that is press-fitted into the photosensitive drum 1 to fix the coupling member 28 to the photosensitive drum 1. Specifically, the dimensions are such that the cylinder inner diameter of the photosensitive drum 1 and the outer shape of the press-fit portion 72d have an interference fit relationship. However, this relationship is not limited to the above when a configuration is used in which the fastening force is increased by caulking or when the cylinder inner diameter and the press-fit portion 72d are fixed with an adhesive.

[0089] 10, the crimping groove 72e is a groove shape (recess) provided on the photosensitive drum 1 side of the press-fit portion 72d in the Z-axis direction. The crimping grooves 72e are arranged in two locations evenly spaced around the rotation axis of the coupling member 28. Note that the crimping grooves 72e and the flange portion 75 are arranged to overlap with each other in the rotation axis direction of the drum unit 30 (the rotation axis direction of the coupling member 28).

[0090] The axis (rotation axis, rotation center line) Ax of the drum unit 30 refers to an imaginary straight line that extends through the rotation center of the drum unit 30. The axis of the photosensitive drum 1 and the axis of the coupling member 28 are arranged so as to almost overlap, and these axes almost coincide with the axis Ax of the drum unit 30. Therefore, unless otherwise specified, the axes are used interchangeably.

[0091] The axial direction (rotational axis direction) means the direction in which the axis extends. The axial direction of the drum unit 30 and the axial direction of the coupling member 28 are the same as the longitudinal direction (Z direction) of the drum unit 30.

[0092] Furthermore, "X and Y overlap in the A direction" means that when X and Y are projected onto a line extending parallel to the A direction, at least a part of the projection area of ​​X overlaps with at least a part of the projection area of ​​Y on that line.

[0093] That is, when the crimping groove 72e and the flange portion 75 are projected onto the rotation axis Ax of the drum unit 30 (coupling member 28), the projected area of ​​the crimping groove 72e and the projected area of ​​the flange portion 75 at least partially overlap each other on the axis.

[0094] When projecting something onto a line, the projection direction is perpendicular to the line unless otherwise specified. For example, "projecting A onto an axis" means "projecting A onto the axis in a direction perpendicular to the axis."

[0095] The photosensitive drum 1 is plastically deformed by crimping a portion of the end of the photosensitive drum 1 on the side of the coupling member 28. This causes a portion of the photosensitive drum 1 to fit inside the crimping groove 72e, firmly fixing the photosensitive drum 1 and the coupling member 28. Crimping refers to the action of joining portions of multiple parts by plastic processing.

[0096] In this embodiment, the photosensitive drum 1 is coupled to the coupling member 28 by plastically deforming a portion of the cylinder (aluminum). In this embodiment, the crimping groove 72e is used as an example of a means for firmly fixing the coupling member 28 to the photosensitive drum 1, but other fixing means can also be used, such as fixing the area between the inner diameter of the cylinder and the press-fit portion 72d with an adhesive. Therefore, the crimping groove 72e is not an essential component.

[0097] The press-fit guide portion 72f has a shape that makes it easier to assemble the coupling member 28 to the photosensitive drum 1 when assembling the coupling member 28 to the photosensitive drum 1 and ensures that the press-fit portion 72d is stably press-fitted into the photosensitive drum 1. Specifically, the outer diameter of the press-fit guide portion 72f is smaller than the outer diameter of the press-fit portion 72d and the inner diameter of the cylinder of the photosensitive drum 1, and the press-fit guide portion 72f has a guide taper 72g on its tip side in the direction of attachment to the photosensitive drum 1. The guide taper 72g is an inclined portion provided on the coupling member 28 to make it easier to insert the coupling member 28 into the interior of the photosensitive drum 1.

[0098] As described above, the cylindrical portion 71 has a bearing portion 71c on the tip side (Z1 direction side) of its outer circumferential surface 71a (shown in FIGS. 4 and 10). The cylindrical portion 71 also has a notch shape 71d on the press-fit portion 72e side of the bearing portion 71c. The notch shape 71d forms a base portion 74 that supports the engaging portion 73 so that it can be elastically deformed (the engaging portion 73 will be described in detail later). In other words, in the Z direction, the notch shape 71d, the engaging portion 73, and the base portion 74 are provided between the bearing portion 71c and the press-fit portion 72e.

[0099] In other words, the coupling member 28 has the notched shape 71d, the engaging portion 73, and the bearing portion 71c having a cylindrical outer shape on the Z1 direction side (axially outward) of the base portion 74. By adopting such a shape, the engaging portion 73 and the base portion 74 are not exposed on the outer surface of the cartridge 7. Therefore, the engaging portion 73 and the base portion 74 can be protected by the drum unit bearing member 39R and the bearing portion 71c.

[0100] This prevents the user from unintentionally touching the engaging portion 73 and the base portion 74, and also prevents the engaging portion 73 and the base portion 74 from being directly hit by something when the cartridge 7 is dropped.

[0101] 12, the inner peripheral surface 71b of the cylindrical portion 71 has a tapered shape at the front end (Z1 direction). This tapered shape is an inclined portion (inclined surface) for guiding the main body drive shaft 101 inserted inside the cylindrical portion 71.

[0102] Furthermore, when the main body drive shaft 101 is inserted into the cylindrical portion 71, the inner peripheral surface 71b of the cylindrical portion 71 guides the main body drive shaft 101. The inner peripheral surface 71b of the cylindrical portion 71 is a guide portion on the cartridge side for guiding the main body drive shaft 101, and has a circumferential shape.

[0103] When the cartridge 7 is inserted into the image forming apparatus main body 100A, the main body drive shaft 101 can be guided to follow the coupling member 28 so as to reduce the axial misalignment between the rotation center of the cylindrical portion 71 and the rotation center of the shaft portion 101f. Also, as shown in FIG. 7, the inner diameter D2 of the inner circumferential surface 71b is larger than the outer diameter D6 of the shaft portion 101f of the main body drive shaft 101. Therefore, after the cartridge 7 has been completely attached to the image forming apparatus main body 100A, the inner circumferential surface 71b does not come into contact with the rough guide portion 101g.

[0104] 13, the flange portion 75 has a shape that protrudes radially outward beyond the press-fit portion 72d. When the coupling member 28 is attached to the photosensitive drum 1, the flange portion 75 has a shape that determines the positions of the photosensitive drum 1 and the coupling member 28 in the Z direction by causing the end face of the photosensitive drum 1 to abut against an end face 75b of the flange portion 75.

[0105] 11, the engaging portions 73 are arranged in three locations at equal intervals (120° intervals, approximately equal intervals) around the circumference of the coupling member 28. Similarly, the base portions 74 and the cutout shapes 71d are also arranged in three locations at equal intervals around the circumference of the cylindrical portion 71. The base portion 74 is formed by the cutout shapes 71d. The base portion 74 has a fixed end on the cylindrical portion 71 and is shaped so as to be elastically deformable with the fixed end as a fulcrum.

[0106] The base portion 74 is a portion (extending portion) that extends along the axial direction of the coupling member 28 (axial direction of the photosensitive drum unit 30). In other words, the base portion 74 extends at least outward in the axial direction.

[0107] An engaging portion 73 is provided at the tip (free end) of the base portion 74. The engaging portion 73 is a protruding portion (projection, convex portion) that protrudes toward the inside in the radial direction of the coupling member 28 (the inside in the radial direction of the photosensitive drum unit 30). In other words, the engaging portion 73 is a protruding portion (convex portion, protruding portion) that protrudes in a direction intersecting the direction in which the base portion 74 extends.

[0108] It is desirable that the cross-sectional shape of the engaging portion 73 is not circular (non-circular), and more specifically, that it has a corner, in order to ensure that the engaging portion 73 engages with the drive transmission groove 101a formed in the main body drive shaft 101.

[0109] That is, when the support portion (engagement portion 73) is cut perpendicularly to the axis Ax of the coupling member at the position where the drive receiving portion 73a is provided, the cross section is non-circular.

[0110] The engaging portion 73 is supported by an elastically deformable base portion 74, and can move in the radial direction of the coupling member 28 due to deformation of the base portion 74. In other words, the base portion 74 is a deforming portion (elastically deforming portion, flexible portion) that deforms when subjected to an external force and has a restoring force in the direction of returning to its natural position.

[0111] Specifically, when the engaging portion 73 comes into contact with the outer peripheral surface of the main body drive shaft 101, it undergoes elastic deformation, causing the engaging portion 73 to move radially outward along the outer peripheral surface of the main body drive shaft 101. Thereafter, when the engaging portion 73 reaches the same position (in phase) as the main body drive transmission groove 101a provided on the outer peripheral surface of the main body drive shaft 101, the elastic deformation of the engaging portion 73 is released. Then, the engaging portion 73 moves radially inward, allowing a portion of the engaging portion 73 to enter the main body drive transmission groove 101a.

[0112] It is preferable to arrange a plurality of engaging portions 73 in the circumferential direction of the cylinder in terms of driving stability.

[0113] Further, the driving force receiving surface 73a of the coupling member 28 has a shape twisted around the axis of the coupling member 28, and in this embodiment, the amount of twist is the same as that of the main body driving force transmitting surface 101b.

[0114] It is sufficient that the driving force receiving surface 73a has different phases in the rotation direction at the two points where it comes into contact with the drive shaft 101. In other words, the driving force receiving surface 73a does not necessarily have to have a twisted shape as long as it has a configuration that has the same function as a twisted surface.

[0115] For example, the driving force receiving surface 73a may have a shape such that the outer side (Z1 direction side) of the photosensitive drum unit 30 is disposed upstream of the inner side (Z2 direction side) of the photosensitive drum unit 30 in the rotation direction of the photosensitive drum 1. In other words, the straight line connecting the inner end and outer end of the cylinder along the cylinder axial direction of the engaging portion 73 intersects with the rotation axis of the cylinder. The driving force receiving surface 73a is an inclined portion inclined with respect to the axis of the coupling member 28.

[0116] In this way, by making the driving force receiving surface 73a twisted or inclined, when the driving force receiving surface 73a receives driving force, a force is applied to the photosensitive drum unit 30 that pulls it toward the bearing portion 101d of the main body driving shaft 101.

[0117] 8, the engaging portion 73 can be retracted outward in the radial direction of the coupling member 28 (the radial direction of the photosensitive drum unit 30). The driving force receiving surface 73a provided on the engaging portion 73 is inclined with respect to the direction of movement of the engaging portion 73. In the cross-sectional view shown in FIG. 8, line B1 is a line along the direction in which the engaging portion 73 moves when retracting (the direction in which it moves radially). Line B2 is a line along the driving force receiving surface 73a. It can be seen that line B1 and line B2 intersect. As a result, when the driving force receiving surface 73a is in contact with the drive transmission groove 101a, the driving force receiving surface 73a bites into the drive transmission groove 101a, making it difficult for the engaging portion 73 to retract from the drive transmission groove 101a. In other words, the engagement state between the engaging portion 73 and the drive transmission groove 101a is stabilized.

[0118] In particular, the driving force receiving surface 73a is inclined with respect to the movement direction (straight line B1) of the engaging portion 73 so that the inner diameter side (tip side) is positioned further upstream in the rotation direction of the coupling member 28 than the outer diameter side (root side). Therefore, when the coupling member 28 (photosensitive drum unit 30) rotates, the force received from the driving force receiving surface 73 acts in a direction that causes the engaging portion 73 to engage with the main body drive transmission groove 101a. The engagement state between the engaging portion 73 and the main body drive transmission groove 101a is stabilized, preventing the engaging portion 73 from disengaging from the main body drive transmission groove 101a.

[0119] 13, the engaging portion 73 has an insertion tapered surface 73d on the outer side (Z1 direction side) of the photosensitive drum unit 30 in the Z direction. The insertion tapered surface 73d is an inclined portion facing outward in the axial direction. When the coupling member 28 is coupled to the main body drive shaft 101, the insertion tapered surface 73d rides up onto the main body drive shaft 101, causing the engaging portion 73 to retract radially outward. The insertion tapered surface 73d is an installation force receiving portion that receives a force for retracting the engaging portion 73 in the radial direction when the cartridge is installed.

[0120] Furthermore, the engaging portion 73 has a removal tapered surface 73e on the inner side (Z2 direction side) of the photosensitive drum unit 30 in the Z direction as a portion that receives a force during removal. The removal tapered surface 73e is an inclined portion that faces inward in the axial direction. When the cartridge is removed, that is, when the coupling member 28 is detached from the main body drive shaft 101, the removal tapered surface 73e rides up onto the main body drive shaft 101. When the removal tapered surface 73e receives a force from the main body drive shaft, the engaging portion 73 moves radially inward and releases its engagement with the main body drive shaft.

[0121] These configurations can improve the ease of mounting and dismounting of the coupling member 28 to the main body drive shaft 101. Both of the two tapered surfaces are inclined portions inclined relative to the axial direction.

[0122] During attachment, the insertion tapered surface 73d and the hemispherical shape 101c come into contact, and the engaging portion 73 is moved radially outward from the drive shaft. During removal, the removal tapered surface 73e and the main body-side removal taper 101i come into contact, and the engaging portion 73 (driving force receiving surface 73a) is moved radially outward from the main body drive shaft 101. When the driving force receiving portion 73a of the coupling member 28 is attached to or detached from the main body drive shaft 101, it receives a force from the main body drive shaft 101 and moves radially outward more than in its natural state (normal state).

[0123] The engaging portion 73 is also arranged such that the length L2 of the driving force receiving surface 73 satisfies the relationship L1>L2, where L1 is the distance from the front end face of the cylindrical portion 71 to the front end face of the engaging portion 73 in the Z direction.

[0124] The centering portion 76 has a radial positioning portion 76a. The radial positioning portion 76a is a portion for determining the radial position of the main body drive shaft 101. In other words, the radial positioning portion 76a is a portion for determining the radial position of the coupling member 28 relative to the main body drive shaft 101. In other words, the radial positioning portion 76a is a positioning portion for determining the relative positional relationship between the main body drive shaft 101 and the coupling member.

[0125] The radial positioning portion 76a has an arc-shaped curved surface that contacts the outer circumferential surface of the main body drive shaft 101, thereby restricting radial movement of the main body drive shaft 101. In other words, the radial positioning portion 76a faces the axial side of the coupling member 28 and is a curved surface that follows the circumferential direction (rotational direction) of the coupling member 28. The radial positioning portion 76a is located axially inward of the inner circumferential surface 71b (see FIG. 12), and the inner diameter of the radial positioning portion 76a is smaller than that of the inner circumferential surface 71b. The inner circumferential surface 71b is a first inner diameter portion with a relatively large diameter, and the radial positioning portion 76a is a second inner diameter portion with a relatively small diameter.

[0126] 14, when viewed along the axial direction of the coupling member 28, the radial positioning portion 76a is disposed at a position that avoids the engaging portion 73. In addition, the radial positioning portion 76a is disposed outward from the tip of the engaging portion 73 (the tip of the driving force receiving surface 73a) in the radial direction of the coupling member 28, and is disposed inward from the fixed end (root portion) of the base portion 74.

[0127] On the other hand, the radial positioning portion 76a is disposed at a position overlapping with the engaging portion 73 in the Z direction (see FIG. 15). In other words, when the radial positioning portion 76a and the engaging portion 73 are projected perpendicularly onto the axis of the coupling member 28, at least a portion of their regions overlap with each other on the axis.

[0128] With this arrangement, even if the main body drive shaft 101 tilts around the radial positioning portion 76a as a fulcrum, the relative position between the main body drive shaft 101 and the engagement portion 73 is unlikely to change, and the engagement between the main body drive shaft 101 and the engagement portion 73 is unlikely to be affected.

[0129] The inner diameter D7 of the radial positioning portion 76a is approximately the same as the outer diameter D5 of the shaft portion 101f of the main body drive shaft 101. As described above, the engaging portions 73 are arranged in three locations at equal intervals around the circumference of the coupling member 28 (at 120° intervals, approximately equal intervals). Accordingly, the radial positioning portions 76a are also arranged in three locations at equal intervals around the circumference of the coupling member 28. As a result, the radial positioning portions 76a can position the coupling 28 radially with respect to the shaft portion 101f at three locations.

[0130] The alignment portion 76 also has an abutment portion 76b. As shown in Figure 15, the abutment portion 76b abuts against a hemispherical shape 101c when the drive force of the main body drive shaft 101 is transmitted to the coupling member 28. The hemispherical shape 101c is a substantially hemispherical portion provided at the tip of the main body drive shaft 101.

[0131] In addition, the abutment portion 76b is positioned within the coupling member 28 so that when the abutment portion 76b and the hemispherical shape 101c are in contact in the Z direction, the center 101h of the hemispherical shape 101c of the main body drive shaft 101 is within the range of the driving force receiving surface 73a.

[0132] In this embodiment, the coupling member 28 is formed as one body. However, for example, the coupling member 28 may be formed as two bodies by making the alignment portion 76 a separate body from the other parts. Furthermore, the other parts may also be separate bodies, and the coupling member 28 may be formed by combining three or more members.

[0133] [Installing the cartridge into the image forming device] 16 and 17, the attachment and detachment of the process cartridge 7 to and from the main body of the image forming apparatus will be described.

[0134] FIG. 16 is a perspective view for explaining the mounting of the cartridge 7 into the image forming apparatus main assembly 100A.

[0135] FIG. 17 is a cross-sectional view for explaining the mounting operation of the cartridge 7 into the image forming apparatus main body 100A.

[0136] The image forming apparatus main body 100A of this embodiment is configured so that a cartridge can be installed in a substantially horizontal direction. Specifically, the image forming apparatus main body 100A has a space inside it where the cartridge can be installed. The image forming apparatus main body 100A also has a cartridge door 104 (front door) on the front side (the direction in which a user stands during use) for inserting the cartridge into the space.

[0137] As shown in Figure 16, the cartridge door 104 of the image forming apparatus main body 100A is provided so as to be able to open and close. When the cartridge door 104 is opened, a cartridge lower guide rail 105 for guiding the cartridge 7 is disposed at the bottom of the space, and a cartridge upper guide rail 106 is disposed at the top. The cartridge 7 is guided to the mounting position by upper and lower guide rails (105, 106) provided at the top and bottom of the space. The cartridge 7 is inserted into the mounting position substantially along the axis of the photosensitive drum unit 30.

[0138] The operation of mounting and demounting the cartridge to and from the image forming apparatus main body 100A will be described below with reference to FIG.

[0139] 17(a), when the cartridge 7 starts to be inserted, the drum unit bearing member 39R and the photosensitive drum 1 do not come into contact with the intermediate transfer belt 5. In other words, the dimensions are such that the photosensitive drum 1 and the intermediate transfer belt 5 do not come into contact with each other when the rear end of the cartridge 7 in the insertion direction is supported by the cartridge lower guide rail 105.

[0140] 17(b), the image forming apparatus main body 100A is provided with a rear cartridge lower guide 107 that protrudes upward in the direction of gravity from the cartridge lower guide rail 105 at the rear side in the insertion direction of the cartridge lower guide rail 105. This rear cartridge lower guide 107 is provided with a tapered surface 107a at the front side in the insertion direction of the cartridge 7. As the cartridge 7 is inserted, it rides up on the tapered surface 107a and is guided to the mounting position.

[0141] The position and shape of the rear cartridge lower guide 107 may be determined so that a part of the cartridge does not rub against the image forming area 5A of the intermediate transfer belt 5 when the cartridge is inserted into the apparatus main body 100A. Here, the image forming area 5A refers to the area on the intermediate transfer belt 5 where the toner image to be transferred to the recording material 12 is carried. In this embodiment, of the cartridge 7 that maintains its installation orientation, the unit bearing member 39R provided at the rear side in the insertion direction of the cartridge 7 protrudes most upward in the direction of gravity. Therefore, the arrangement and shape of each element may be appropriately selected so that the locus drawn by the end of the rearmost end of the drum unit bearing member 39R in the insertion direction during insertion (hereinafter referred to as the insertion locus) does not interfere with the image forming area 5A.

[0142] Thereafter, as shown in FIG. 17(c), the cartridge 7 is inserted further toward the rear of the image forming apparatus main body 100A, from the state where it has climbed onto the rear cartridge lower guide 107. Then, the drum unit bearing member 39R abuts against the rear cartridge positioning portion 108 provided on the image forming apparatus main body 100A. At this time, the cartridge 7 (photosensitive drum unit 30) is tilted by approximately 0.5 to 2 degrees from the state in which it is completely attached to the image forming apparatus main body 100A (FIG. 17(d)). In other words, in the insertion direction of the cartridge 7, the downstream side of the cartridge 7 (photosensitive drum unit 30) is raised higher than the upstream side.

[0143] 17(d) is a diagram showing the state of the apparatus main body and cartridge with cartridge door 104 closed. Image forming apparatus 100A has a front cartridge lower guide 109 on the front side in the insertion direction of cartridge lower guide rail 105. This front cartridge lower guide 109 is configured to move up and down in conjunction with the opening and closing of cartridge door (front door) 104.

[0144] When the user closes the cartridge door 104, the front cartridge lower guide 109 rises. Then, the drum unit bearing member 39L and the front cartridge positioning portion 110 of the image forming apparatus main body 100A come into contact with each other, and the cartridge 7 is positioned relative to the image forming apparatus main body 100A.

[0145] By the above operation, the cartridge 7 is completely mounted in the image forming apparatus main body 100A.

[0146] The cartridge 7 is removed from the image forming apparatus main body 100A in the reverse order of the above-described insertion operation.

[0147] As described above, the oblique mounting configuration can be used to prevent friction between the photosensitive drum and the intermediate transfer belt when the cartridge 7 is mounted in the apparatus main body 100A, which can prevent minute scratches (scratches) from occurring on the surface of the photosensitive drum or the surface of the intermediate transfer belt.

[0148] Furthermore, the configuration disclosed in this embodiment simplifies the configuration of the image forming apparatus main body 100A compared to a configuration in which the cartridge is moved horizontally into the apparatus main body, mounted thereon, and then the entire cartridge is lifted up.

[0149] [Coupling member engagement process with main body drive shaft] Next, the engagement process between the coupling member 28 and the main body drive shaft 101 will be described in detail with reference to FIGS.

[0150] FIG. 18 is a cross-sectional view for explaining the operation of attaching the coupling member 28 to the main body drive shaft 101. As shown in FIG.

[0151] Figure 19 is a cross-sectional view illustrating the attachment operation of the coupling member 28 to the main body drive shaft 101 when the main body drive transmission groove 101a and the engagement portion 73 (driving force receiving surface 73a) are not in phase with each other and the main body drive shaft 101 rotates to bring them into phase with each other.

[0152] Figure 18(a) is a diagram showing a state in which the coupling member 28 has begun to engage with the main body drive shaft 101. Figure 18(e) shows a state in which the cartridge 7 has been attached to the image forming apparatus main body 100A. In particular, Figure 18(e) shows a state in which the front cartridge lower guide 109 has risen as the cartridge door 104 is closed, and the cartridge 7 has been positioned relative to the image forming apparatus main body 100A.

[0153] 18(b) to 18(d) are diagrams illustrating the process of attaching the coupling member 28 to the main body drive shaft 101 between Figures 18(a) and 18(e). Note that the main body drive shaft 101 hangs downward in the direction of gravity at a small angle due to its own weight.

[0154] FIG. 19 is a diagram for explaining a state in which the main body drive transmission groove 101a and the engagement portion 73 (drive force receiving surface 73a) are not in phase with each other.

[0155] As explained with reference to Figure 17(b), the cartridge 7 rides up on the rear cartridge lower guide 107. That is, the cartridge 7 gradually increases its inclination from Figure 17(a) to Figure 17(b), and reaches a state in which it is tilted by approximately 0.5 to 2 degrees. Then, the cartridge 7 rides up on the rear cartridge lower guide 107.

[0156] Similarly, as shown in Figure 18(a), the coupling member 28 is inserted into the main body drive shaft 101 at an angle of approximately 0.5 to 2° relative to the state in which the cartridge 7 is positioned relative to the image forming apparatus main body 100A (shown in Figure 18(e)).

[0157] As shown in Figure 6, the main body drive shaft 101 is cantilevered at the bearing portion 101d. The gear portion 101e is engaged with a gear (not shown) that transmits drive to the gear portion 101e. Figure 18(a) is a diagram showing a state in which the main body drive shaft 101 is not in contact with the coupling member 28. In this state, compared to the state in which the cartridge 7 is positioned relative to the image forming apparatus main body 100A (shown in Figure 18(e)), the cartridge 7 tilts by an angle θ1 determined by its own weight and the direction of engagement, with the bearing portion 101d as the rotation center.

[0158] As shown in FIG. 18(b), the tip of the inner peripheral surface 71b of the cylindrical portion 71 of the coupling member 28 first abuts against the rough guide portion 101g of the main body drive shaft 101. As shown in the figure, the main body drive shaft 101 is configured to be cantilevered at the bearing portion 101d. Therefore, the main body drive shaft 101 is inserted into the coupling member 28 with the rough guide portion 101g of the main body drive shaft 101 aligned with the inner peripheral surface 71b of the coupling member 28. As described above, the engaging portion 73 is positioned such that the length L2 of the driving force receiving surface 73 satisfies the relationship L1 > L2, where L1 is the distance from the front end face of the cylindrical portion 71 to the front end face of the engaging portion 73 in the Z direction (see FIG. 13). Therefore, before the hemispherical shape 101c at the tip of the main body drive shaft 101 abuts against the engaging portion 73, the rough guide portion 101g of the main body drive shaft 101 is aligned with the inner peripheral surface 71b of the coupling member 28. As a result, the main body drive shaft 101 is guided relative to the coupling member 28, preventing the ball-returning shape 101c at the tip of the main body drive shaft 101 from hitting an unexpected location on the engaging portion 73 or the base portion 74. This protects the engaging portion 73 and the indicator portion 74.

[0159] 18(c), when the coupling member 28 is further inserted toward the rear side of the main body drive shaft 101 from the position shown in FIG. 18(b), the tapered insertion surface 73d of the engaging portion 73 comes into contact with the hemispherical shape 101c at the tip of the main body drive shaft 101. The inclined surface of the tapered insertion surface 73d and the spherical shape of the hemispherical shape 101c guide the main body drive shaft 101 to approximately the center of the three engaging portions 73.

[0160] When the coupling member 28 is further inserted into the main body drive shaft 101, the base 74 elastically deforms radially outward so that the engaging portion 73 conforms to the hemispherical shape 101c. As a result, as shown in Figure 19(a), the engaging portion 73 moves (retracts) to the outer diameter of the shaft portion 101f of the main body drive shaft 101. This movement causes the coupling member 28 to be attached to the main body drive shaft 101 until the removal taper surface 73e of the engaging portion 73 is located further back in the Z direction than the main body-side removal taper 101i of the main body drive shaft 101, as shown in Figure 18(d).

[0161] Thereafter, as described above, the cartridge 7 is lifted up so that the drum unit bearing member 39L of the cartridge 7 abuts against the front cartridge positioning portion 110. By lifting the cartridge 7, the cartridge 7 is positioned relative to the image forming apparatus main body 100A (shown in FIG. 17(d)). This movement of the cartridge 7 eliminates the inclination of the coupling member 28, as shown in FIG. 18(e).

[0162] 19(b), when the main body drive shaft 101 rotates, the main body drive transmission groove 101a and the engaging portion 73 are in phase with each other. This releases the elastic deformation of the base 74, and a part of the engaging portion 73 enters the main body drive transmission groove 101a, thereby engaging the coupling member 28 and the main body drive shaft 101.

[0163] When the phase of the main body drive transmission groove 101a and the engagement portion 73 are aligned, the elastic deformation of the base portion 74 is released at the stage shown in Figure 17(d), resulting in the state shown in Figure 19(b), and the driving force of the main body drive shaft 101 can be transmitted to the cartridge 7 via the coupling member 28.

[0164] As described above, when the cartridge 7 is mounted in the apparatus main body 100A, the main body drive transmission groove 101a and the engaging portion 73 are brought into an engageable state. Therefore, it is not necessary to move the main body drive shaft 101 to engage with the coupling member 28. In other words, it is not necessary to provide the main body 100A of the image forming apparatus with a mechanism for moving the main body drive shaft 101 so that it engages with the coupling member 28. In conventional configurations, a mechanism for moving the main body drive shaft 101 so that it engages with the coupling member 28 after the cartridge 7 is mounted in the image forming apparatus main body 100A is provided. However, in this embodiment, such a mechanism can be omitted from the apparatus main body 100A.

[0165] When the cartridge 7 is mounted in the apparatus main body 100A, the engaging portion 73 of the coupling member 28 comes into contact with the main body drive shaft 101 and retreats radially outward. The engaging portion 73 then moves radially inward to engage with the groove of the main body drive shaft 101 (main body drive transmission groove 101a).

[0166] Here, it is also possible to provide a groove in the coupling member for receiving the drive force, and to provide a movable part on the main body drive shaft 101 side that can move radially to engage with the groove. However, the image forming apparatus main body 100A is required to have higher durability than the cartridge 7. In order to enhance the durability of the image forming apparatus main body 100A, it is preferable to provide a movable part (engagement part 73) that moves radially on the coupling member 28 side of the cartridge 7, as in this embodiment.

[0167] [Removing the coupling member from the drive shaft] The operation of removing the coupling member 28 from the main body drive shaft 101 will be described with reference to FIG.

[0168] FIG. 20 is a cross-sectional view illustrating the operation of removing the coupling member 28 from the main body drive shaft 101.

[0169] 20(a), the driving force receiving surface 73a and the main body drive transmission surface 101b are in contact with each other when the rotation of the main body drive shaft 101 stops. In this state, a part of the engaging portion 73 is inserted into the main body drive transmission groove 101a.

[0170] When the cartridge door 104 is opened, the front cartridge lower guide 109 descends, and the drum unit bearing member 39L moves away from the front cartridge positioning portion 110 of the image forming apparatus main body 100A. At this time, the coupling member 28 and the main body drive shaft 101 are tilted by approximately 0.5 to 2 degrees with respect to the fully mounted state (Z direction), as shown in Figure 20(b).

[0171] When removal of the cartridge 7 from the image forming apparatus main body 100A begins, the removal tapered surface 73e of the engaging portion 73 abuts against the main body-side removal taper 101i, as shown in Figure 20(c). When the removal tapered surface 73e abuts against the main body-side removal taper 101i, the base 74 begins to elastically deform, and the engaging portion 73 moves radially outward along the main body-side removal taper 101i.

[0172] 19(a), the base 74 further elastically deforms, and the engaging portion 73 moves to the outer diameter of the shaft portion 101f of the main body drive shaft 101. When the engaging portion 73 moves to the outer diameter of the shaft portion 101f, the coupling member 28 can be removed from the main body drive shaft 101, as shown in FIG. 20(d).

[0173] Furthermore, when the coupling member 28 is removed from the main body drive shaft 101, the elastic deformation of the base portion 74 is released, and the position of the engaging portion 73 also returns to the position before the elastic deformation, as shown in FIG. 20(e).

[0174] By the above operation, the coupling member 28 can be removed from the main body drive shaft 101.

[0175] In this embodiment, as shown in Fig. 12, the base 74 and the U-shaped cutout 71d are disposed on the Z1 direction side of the engaging portion 73, but as shown in Fig. 21, the engaging portion 73 may be disposed on the Z1 direction side of the base 74 and the U-shaped cutout 71d. This can be selected appropriately depending on the arrangement of the main body drive shaft 101 and the coupling member 28 inside the image forming apparatus main body 100A.

[0176] As described above, by using the coupling member 28 and main body drive shaft 101 of this embodiment, it is possible to omit a mechanism for moving the main body drive shaft 101. That is, in this embodiment, when the cartridge 7 is mounted in the image forming apparatus main body 101A, the coupling member 28 is disposed in a position where it can engage with the main body drive shaft 101. Therefore, it is not necessary to move the main body drive shaft 101 relative to the coupling member 28 to bring the coupling member 28 and the main body drive shaft 101 into an engageable state.

[0177] Furthermore, by using the coupling member 28 of this embodiment, the engaging portion 73 and the base portion 74 are not exposed to the outer surface of the cartridge 7. This makes it possible to protect the engaging portion 73 and the base portion 74.

[0178] In this embodiment, the entire driving force receiving portion 73a and its support portion (the engaging portion 73 and the base portion 74) are disposed axially inward of the bearing portion of the drum unit bearing member 39R. However, if at least a portion of the driving force receiving portion 73a and its support portion (the engaging portion 73 and the base portion 74) are disposed axially inward of the bearing portion of the bearing member 39R, the engaging portion 73 and the base portion 74 can be protected. Furthermore, even if the bearing portion is disposed so as to overlap the driving force receiving portion 73a and its support portion (the engaging portion 73 and the base portion 74) in the axial direction, the driving force receiving portion 73a and its support portion can be protected.

[0179] In other words, when the bearing portion, engaging portion 73, and base portion 74 are projected onto the axis of the coupling member, the projected areas of the engaging portion 73, driving force receiving portion 73a, and base portion 74 may be arranged so that they overlap the projected area of ​​the bearing portion.

[0180] <Example 2> The second embodiment will be described with reference to FIGS.

[0181] FIG. 22 is a cross-sectional perspective view of a coupling member 228 according to the second embodiment.

[0182] FIG. 23 is a perspective view of a coupling member 228 according to the second embodiment.

[0183] FIG. 24 is a view of a coupling member 228 according to the second embodiment as viewed from the inside in the Z direction.

[0184] FIG. 25 is a cross-sectional view for explaining the mounting operation of the coupling member 228 to the main body drive shaft 101 according to the second embodiment.

[0185] FIG. 26 is a view of the coupling member 228 according to the second embodiment as viewed from the outside in the Z direction.

[0186] The same names are used for elements corresponding to those in Example 1. Regarding these elements, the configurations and operations that differ from those of the elements described above will be particularly described in detail, and explanations of the same points as those of the elements described above may be omitted.

[0187] This embodiment is characterized in that at least a part of the support portion (engagement portion 273 and base portion 274) that movably supports the driving force receiving portion 273a is disposed inside the photosensitive drum 1. In particular, it is characterized in that the fixed end of the support portion (i.e., the root portion 274a of the base portion 274) is disposed inside the photosensitive drum 1 (see FIG. 25). This will be described in detail below.

[0188] In this embodiment, a coupling member 228 is provided as a flange member attached to the end of the driving side of the cylinder (photosensitive drum 1). The coupling member 228 has an engaging portion 273 configured to engage with the main body drive shaft 101, and a base portion 274 for supporting the engaging portion 273.

[0189] The engagement portion 273 has a driving force receiving surface 273a. The driving force receiving surface 273a is a driving force receiving portion (driving force receiving portion) that can receive a driving force (rotational force) for rotating the photosensitive drum 1 from the outside of the cartridge (the outside of the drum unit), that is, from the main body of the apparatus.

[0190] The engaging portion 273 and the base portion 274 are supporting portions for supporting the driving force receiving surface (driving force receiving portion) 273a.

[0191] In Example 1, a notch 71d is provided in the cylindrical portion 71, and the base portion 74 extends from the cylindrical portion 71. The base portion 74 is shaped to be disposed between the bearing portion 71c and the attachment portion 72 in the Z direction.

[0192] Consider the case where the drive transmission groove 101a of the main body drive shaft 101 is stored for a long period of time in a state where the phases of the drive transmission groove 101a and the engagement portion 73 of the coupling member 28 are not aligned (as shown in FIG. 19(a)). In this case, there is a concern that creep deformation may occur not only in the base portion 74 but also in the vicinity of the root portion 74a of the base portion 74 of the cylindrical portion 71.

[0193] Here, high accuracy of alignment between the bearing portion 71c and the press-fit portion 72d is maintained so that the axis of the bearing portion 71c and the axis of the press-fit portion 72d of the mounting portion 72 are coaxial. However, even in this case, the amount of creep deformation near each root portion 74a of the cylindrical portion 71 is not necessarily constant. For this reason, if creep deformation also occurs near the root portion 74a of the base portion 74 located therebetween, there is a concern that the accuracy of alignment that keeps the central axis of the bearing portion 71c and the central axis of the press-fit portion 72d coaxial will decrease.

[0194] If the coaxial accuracy of the axis of the bearing portion 71c and the axis of the press-fit portion 72d decreases, there is a possibility that the coaxial accuracy of the axis of the bearing portion 71c and the axis of the photosensitive drum 1 will also decrease. As a result, the rotation accuracy of the photosensitive drum 1 will also decrease, which may affect image quality.

[0195] Therefore, in this embodiment, the base portion 274 is shaped to extend from the inner circumferential cylinder 272h of the attachment portion 272 toward the engaging portion 273 toward the outside in the axial direction of the coupling member 228. In other words, the base portion 274 is an extending portion (extending portion, extended portion) that extends at least in the axial direction. In addition, the engaging portion 273 is a protruding portion (convex portion, protruding portion) supported by the base portion 274.

[0196] The mounting portion 272 has a plurality of ribs around its periphery but is essentially a cylindrical portion having a cylindrical shape, and is a portion (inner periphery contact portion, fixed portion) that comes into contact with and is fixed to the inner periphery of the photosensitive drum 1. In addition, the cylindrical portion 271 is provided outside the mounting portion 272 in the axial direction.

[0197] The direction in which the engaging portion 273 projects intersects with the direction in which the base portion 274 extends. The engaging portion 273 projects at least radially inward of the coupling member.

[0198] As in the first embodiment, the engaging portion 273 is provided with a driving force receiving portion for receiving a driving force from the outside of the drum unit 30 (i.e., the drive shaft 101). The engaging portion 273 and the base portion 274 are supporting portions that support the driving force receiving portion 273a so that the driving force receiving portion 273a is movable at least in the radial direction of the coupling member. More specifically, the base portion 274 is deformed with its fixed end as a starting point, so that the driving force receiving portion 273a is movable at least in the radial direction of the coupling member.

[0199] The inner cylinder 272h is the inner diameter portion of the attachment portion 272 and has a cylindrical shape.

[0200] By providing the root portion (rear end) 274a of the base 274 on the inner cylindrical member 272h, even if the vicinity of the root portion 274a of the base 274 undergoes creep deformation, the influence of this deformation on the bearing portion 271c of the cylindrical member 271 can be suppressed. In other words, because the outer periphery (press-fit portion 272d) of the mounting portion 272 is covered by the photosensitive drum 1, the mounting portion 272 is less likely to deform. Therefore, even if the root 274a of the base 274 deforms, deformation of the mounting portion 272 itself connected to the base 274 is suppressed. As a result, deformation of the entire coupling member 228 is suppressed, and deformation of the bearing portion 271c provided on the tip side of the coupling member 228 is also suppressed.

[0201] Furthermore, by attaching the base 274 to the mounting portion 272, which is less likely to deform, it is possible to prevent deformation or tipping of the base 274. In other words, by locating the root 274a of the base 274 on the inner circumferential cylinder 272h of the mounting portion 272, it is possible to prevent the root 274a from tipping. Therefore, when the coupling member 228 receives drive from the main body drive shaft 101, it can contribute to stable rotation of the photosensitive drum 1.

[0202] Note that if the difference between the outer diameter of the press-fit guide portion 272f and the inner diameter of the inner circumferential cylinder 272h is not large enough, it may not be possible to form both the press-fit guide portion 272f and the inner circumferential cylinder 272h into a circular shape. In this case, the press-fit guide portion 272f may have a shape in which multiple ribs are arranged radially, as in this embodiment. Even with such a shape, the press-fit portion 272d can be stably press-fitted into the photosensitive drum 1.

[0203] 23, multiple rib shapes are radially arranged on the outer periphery of the mounting portion 272, and these rib shapes form the press-fit guide portion 272f. As shown in FIG. 24, the root portion 274a of the base portion 274 is arranged at a position corresponding to the multiple ribs that form the press-fit guide 272f. As a result, when a driving force is received from the main body drive shaft 101, it is transmitted from the root portion 274a through the ribs to the press-fit portion 272d, which further prevents the inner cylinder 272h from being deformed by the driving force.

[0204] 25, when the base 274a of the base portion 274 is provided in the attachment portion 272, the base 274a is disposed inside the photosensitive drum (drum cylinder) 1. In other words, the base portion 274 and the photosensitive drum 1 are projected onto the axis Ax of the photosensitive drum 1 (=axis Ax of the coupling member 228). Then, part of the projection area A274 of the base portion 274 (the projection area on the side of the base 274a) overlaps part of the projection area A1 of the photosensitive drum 1 on the axis.

[0205] When we say that "A is located inside the photosensitive drum 1," it means that A is disposed inside the photosensitive drum whether the photosensitive drum is viewed along the axis Ax or perpendicular to the axis Ax.

[0206] In this embodiment, the base 274 is arranged so that a portion of the area on the root 274a side overlaps the area of ​​the photosensitive drum 1, but the entire base 274 may be arranged so that it overlaps the photosensitive drum 1. In other words, the entire base 274 may be arranged inside the photosensitive drum 1. Such a configuration will be described later using Example 3 (see FIG. 28).

[0207] Next, the engaging portion 273 will be described. As shown in Figures 22 and 25, a taper 273f is provided on the outer diameter side of the engaging portion 273. As in Example 1, in this example, when the drive transmission groove 101a of the main body drive shaft 101 and the engaging portion 273 are not aligned in phase, the base 274 deforms and the engaging portion 273 retracts radially outward. This retraction action moves the engaging portion 273 away from the main body drive shaft 101, allowing the coupling member 228 to be attached to the main body drive shaft 101. When the coupling member 228 is attached to the main body drive shaft 101, the removal taper surface 273e of the engaging portion 273 moves further back in the Z direction than the main body-side removal taper 101i of the main body drive shaft 101.

[0208] In the process of attaching the coupling member 228 to the main body drive shaft 101, the amount of radial outward movement of the engaging portion 273 increases as the distance from the root portion 274a of the base portion 274 increases. Without the taper 273f, if the engaging portion 273 were to retract significantly, it would interfere with the inner circumferential surface 271b of the cylindrical portion 271, as shown by the dotted line in Figure 25(a). Therefore, by providing the taper 273f, the engaging portion 273 does not interfere with the inner circumferential surface 271b of the cylindrical portion 271, even if it moves significantly in the radial direction. As a result, the outer diameter D5 of the shaft portion 101f of the main body drive shaft 101 can be maximized.

[0209] When the base portion 274 is in a state where it is released from elastic deformation (in its natural state), the distance between the base portion 274 and the inner surface (inner circumferential surface 271b) of the coupling member 228 increases from the rear end to the front end.

[0210] 25(b), as in the first embodiment, when the drive transmission groove 101a and the engaging portion 273 are aligned with each other, the elastic deformation of the base portion 274 is released. Then, the engaging portion 273 moves radially inward and enters the drive transmission groove 101a. Drive can now be transmitted from the main body drive shaft 101 to the coupling member 228 via the engaging portion 273.

[0211] 22 and 26, similarly to the first embodiment, the centering portion 276 has a radial positioning portion 276a. The radial positioning portion 276a is located at a position overlapping with the engaging portion 273 in the Z direction (axial direction). In other words, when the radial positioning portion 276a and the engaging portion 273 are projected onto the axis of the coupling member 228 (axis of the photosensitive drum 1), the projected area of ​​the radial positioning portion 276a and the projected area of ​​the engaging portion 273 at least partially overlap each other on the axis.

[0212] On the other hand, when viewed along the axial direction of the coupling member 228, the radial positioning portion 276a is disposed at a position that avoids the engaging portion 273. Figure 24 shows the coupling member 228 as viewed along the axial direction. As can be seen from this figure, the radial positioning portion 276a does not overlap the engaging portion 273, and there is a certain amount of gap between them. This positional relationship is mainly due to manufacturing reasons for the coupling member 228. Details will be described later.

[0213] 22 and 25(b), the aligning portion 276 has an abutting portion 276b. When the drive force of the main body drive shaft 101 is transmitted to the coupling member 228, the abutting portion 276b abuts against the hemispherical shape 101c at the tip of the main body drive shaft 101. This determines the position of the coupling member 228 in the axial direction relative to the main body drive shaft 101.

[0214] Example 3 The third embodiment will be described with reference to FIG.

[0215] FIG. 28 is a cross-sectional view of a coupling member (flange member) 328 and a main body drive shaft 101 according to the third embodiment, cut along the rotation center line (rotation axis).

[0216] Elements corresponding to those in the previous embodiment (especially embodiment 2) are given the same names, and explanations of the same points as the previous elements may be omitted. Regarding these elements, the explanation will focus on the points that are different from the previous elements.

[0217] This embodiment is characterized in that the driving force receiving portion 373a and the supporting portion (engagement portion 373 and base portion 374) that movably supports this driving force receiving portion 373a are entirely disposed inside the photosensitive drum 1.

[0218] The coupling member 328 of this embodiment has an engaging portion 373 for engaging with the main body drive groove 101a, and a base portion 374 for supporting the engaging portion. The base portion 374 is supported by the coupling member 328 by connecting a root 374a to an inner peripheral cylinder 372h of the flange member.

[0219] The engaging portion 373 is provided with a driving force receiving portion that comes into contact with the main body driving groove 101a and receives the driving force from the main body driving groove 101a. The shapes of the engaging portion 373 and its driving force receiving portion are similar to those of the engaging portion 273 and driving force receiving portion 273a in the second embodiment, and therefore detailed description thereof will be omitted.

[0220] The engaging portion 373 is a protruding portion (projecting portion) supported by the base portion 374. The engaging portion 373 protrudes at least radially inward of the coupling member. The base portion 374 is an extending portion (extending portion, extending portion) that extends in a direction intersecting the protruding direction of the engaging portion 373. The base portion 374 is also a deforming portion (elastically deforming portion, flexible portion) that is configured to be elastically deformable.

[0221] The engaging portion 373 is provided with a driving force receiving portion, and the engaging portion 373 and the base portion 374 are supporting portions that movably support the driving force receiving portion.

[0222] In the second embodiment, as shown in FIGS. 22 and 25, the engaging portion 273 is provided inside the cylindrical portion 272 in the Z direction.

[0223] In contrast to this, in this embodiment, the engaging portion 373 is shaped so as to be inside the mounting portion 372 in the Z direction. Here, the mounting portion 372 is a portion that is press-fitted into the inner periphery of the photosensitive drum 1 and attached to the photosensitive drum 1. Therefore, the engaging portion 373 and the driving force receiving portion are located inside the photosensitive drum 1. More specifically, when the photosensitive drum 1 and the engaging portion 373 are projected onto the axis of the photosensitive drum 1, the area of ​​the photosensitive drum 1 and the area of ​​the engaging portion 373 (the area of ​​the driving force receiving portion provided on the engaging portion 373) overlap on the axis. More specifically, the entire area of ​​the engaging portion 373 (driving force receiving portion) is included inside the area of ​​the photosensitive drum 1.

[0224] By adopting such a shape, the photosensitive drum 1 can be positioned closer to the main body drive shaft 101 side (Z1 direction side) in the Z direction compared to Example 2. This can contribute to further miniaturization of the cartridge 7 and the image forming apparatus 100 in the Z direction. Alternatively, the engaging portion 373 and part of the base portion 374 can be positioned deep inside the photosensitive drum 1 where they are difficult for the user to touch, thereby protecting them.

[0225] It is preferable that the entire engagement portion 373 is disposed inside the photosensitive drum 1. However, the above-mentioned effect can be achieved as long as at least a part of the engagement portion 373 (drive force receiving portion) is located inside the photosensitive drum 1. In other words, when the photosensitive drum 1 and engagement portion 373 are projected onto the axis of the photosensitive drum 1, it is sufficient that the area of ​​the photosensitive drum 1 and the area of ​​the engagement portion 373 (area of ​​the drive force receiving portion) at least partially overlap on the axis.

[0226] The base 374 is also located inside the photosensitive drum 1. In other words, when the photosensitive drum 1 and the base 374 are projected onto the axis of the photosensitive drum 1, the projected area of ​​the photosensitive drum 1 and the projected area of ​​the base 374 overlap.

[0227] Example 4 In this section, a fourth embodiment (Embodiment 4) will be described. This embodiment is a partial modification of the configuration of Embodiment 2. Therefore, prior to describing this embodiment, the features of the coupling member 228 shown in Embodiment 2 will be described again.

[0228] In the second embodiment, the coupling member 228 has a base portion 274 that extends in the axial direction of the coupling member 228 from the inner circumferential cylinder 272h of the attachment portion 272 toward the engagement portion 273 (see FIG. 25).

[0229] Furthermore, the alignment portion 276 and the like are arranged so that the following relationship holds when the coupling member 228 is projected onto a projection plane perpendicular to the axis of the coupling member 228. In other words, on the projection plane, the alignment portion 276 does not overlap with the engagement portion 273, the base portion 274, or a region of about 1 mm around them. In other words, when the coupling member 228 is viewed along the axis, there is a gap (gap) of about 1 mm between the alignment portion 276 and the engagement portion 273, and there is also a gap (gap) of about 1 mm between the alignment portion 276 and the base portion 274.

[0230] The reason why the coupling member 228 has the above-described configuration is that the coupling member 228 is manufactured by the manufacturing method described below.

[0231] (Explanation of manufacturing method) The coupling member 228 of the second embodiment is manufactured by injection molding (insert molding) using a mold.

[0232] The configuration of the mold used to mold the coupling member 228 will be described with reference to FIG.

[0233] The coupling member 228 has a shape in which the flange 275 protrudes outward most in the radial direction. When molding such a shape, it is preferable to use a mold as shown in FIG.

[0234] Specifically, as shown in the figure, the mold is composed of two molds: a left mold (cylinder-side mold 60) and a right mold (attachment-side mold 61). By mating the left and right molds, a space (mold cavity, hollow portion) of the same shape as the molded product is formed. Material is poured into this space and solidified within the mold to form the coupling member 228. The mold is configured so that a mold split 62 (a surface for splitting the mold, a surface for mating the molds), where the left and right molds are mated, is located near the space that forms the flange portion 275. The cylinder-side mold 60 is shaped to have a space for molding the outer periphery of the cylindrical portion 271. Similarly, the attachment-side mold 61 is shaped to have a space for molding the attachment portion 272.

[0235] When forming the coupling member 228 using such a mold, it is preferable to use a thermoplastic resin from the viewpoint of mass production. Specifically, materials such as POM and PPS are considered to be suitable. However, other materials may be selected as appropriate to meet requirements such as strength. Specifically, it is also conceivable to use a thermosetting resin or a metal material.

[0236] As described above, the engaging portion 273 has an insertion taper 273d at one end in the Z direction and a removal taper 273e at the other end. Therefore, it is difficult to position the mold half 62 on either end face of the engaging portion 273 in the Z direction. This is because, when using a mold that separates into two pieces, if the mold half 62 is positioned on either of the two end faces of the engaging portion 273, it becomes difficult to remove the molded coupling member 228 from the mold. In other words, when attempting to remove the two molds from the engaging portion 273 after the engaging portion 273 is molded, at least one of the molds will get caught on the engaging portion 273 and will not be able to move.

[0237] Therefore, when molding the coupling member 228 of this embodiment, the mold split 62 is arranged as follows. That is, in the Z direction, the region from the driving force receiving surface 273a to the radially inner side of the base 274 is formed by the attachment portion side mold 61. Also, the region from the insertion taper 273d to the radially outer side of the base 274 is formed by the cylinder side mold 60. For this reason, the centering portion 276 needs to have a shape that does not interfere with the cylinder side mold 60 and the attachment portion side mold 61.

[0238] Specifically, when viewing the coupling member 228 along the Z direction, the alignment portion 276 must not overlap the drive movement portion 273 and the base portion 274 within a range of approximately 1 mm around them (as shown in Figure 26).

[0239] As a result, a gap is generated between the engaging portion 273 and the aligning portion 276, and a gap is generated between the base portion 274 and the aligning portion 276. These gaps allow the base portion 274 and the engaging portion 273 to move to a certain extent in the circumferential direction of the coupling member 228. In such a configuration, it is desirable to increase the rigidity of the base portion 274. This is because if the rigidity of the base portion 274 were to be reduced by using a material that does not provide sufficient rigidity for the base, the following concerns could arise.

[0240] FIG. 29 shows, as a reference example, a configuration in which the material of the coupling member 228 is changed to one with lower rigidity.

[0241] FIG. 29 is an explanatory cross-sectional view of a coupling member according to the fourth embodiment, which is configured without using a coupling member, cut along the rotation center line (rotation axis), to explain deformation of the base and engaging portion.

[0242] In this reference example, when the driving force receiving surface 3273a abuts against the main body drive force transmission surface 101b, the cleaning blade 26, the charging roller 22, and the like apply a load to the photosensitive drum unit 3230. When the driving force is transmitted from the main body drive shaft 101 to the engagement portion 3273, as indicated by the arrow in FIG. 29 , this load may cause the base portion 3274 to tilt downstream in the rotation direction from the root portion 3274a. Because the engagement portion 3273 is located on the free end side of the base portion 3274, tilting the base portion 3274 also tilts the engagement portion 3273 by the amount of tilt of the base portion 3274. As a result, the driving force receiving surface 3273a and the main body drive force receiving surface 101a may not abut against each other, which may prevent the photosensitive drum unit 3230 from being retracted toward the bearing portion 101d of the main body drive shaft 101.

[0243] Furthermore, when the load applied by the aforementioned cleaning blade 26, charging roller 22, etc. fluctuates, the amount of tilt of the base 3274 changes, which may change the amount of rotation of the photosensitive drum 1, potentially affecting image quality.

[0244] Therefore, in Example 2, in order to avoid the concerns described in the Reference Example, a material with high rigidity was selected as the material for the coupling member 228, and the rigidity of the base portion 274 was maintained.

[0245] 30, unlike Example 2, in this Example (Example 4), a backup portion 434a of a backup member 434 is disposed in the gap between the engaging portion 473 and the aligning portion 476, on the upstream side in the rotation direction of the engaging portion 473. This makes it possible to keep the amount of tilt of the base small even if the rigidity of the base 474 is reduced.

[0246] The details of the configuration of this embodiment will be described below with reference to FIGS.

[0247] FIG. 30 is a view of a coupling member 428 according to the fourth embodiment as viewed from the outside in the Z direction.

[0248] FIG. 31 is a view of a flange member 470 according to the fourth embodiment as viewed from the outside in the Z direction.

[0249] FIG. 32 is a cross-sectional view of a coupling member 428 according to the fourth embodiment, cut along the rotation center line (rotation axis).

[0250] FIG. 33 is a view of a flange member 470 according to the fourth embodiment as viewed from the inside in the Z direction.

[0251] FIG. 34 is a view of the backup member 434 according to the fourth embodiment as viewed from the outside in the Z direction.

[0252] FIG. 35 is a cross-sectional view of a coupling member 428 and a main body drive shaft 101 according to the fourth embodiment, cut along the rotation center line (rotation axis).

[0253] FIG. 36 is a perspective view illustrating the assembly of a backup member 434 to a flange member 470 according to the fourth embodiment.

[0254] FIG. 37 is a cross-sectional view of the main body drive shaft 101 and the coupling member 428 according to the fourth embodiment, taken in a direction perpendicular to the rotation axis and at a position passing through the drive force receiving surface (drive force receiving portion) 473a.

[0255] FIG. 38 is a cross-sectional view of a coupling member 428 and a main body drive shaft 101 according to another embodiment of the fourth embodiment, cut along the rotation center line (rotation axis).

[0256] The coupling member 428 is constructed by combining two parts, a flange member 470 and a backup member 434 .

[0257] The flange member 470 is provided with a cylindrical portion 471, an attachment portion 472, a base portion 474, an engagement portion 473, a radial positioning portion 476a of the alignment portion 476, a receiving surface 476c, and a hook portion 472b on the attachment portion 472. The receiving surface 476c is a surface for sandwiching a backup portion 434a (described later) together with the engagement portion 473. The hook portion 472b is shaped to fix the backup member 434 to the flange member 470.

[0258] Engagement portion 473 is provided with a driving force receiving portion that receives a driving force from main body drive shaft 101 of the image forming apparatus main body. Engagement portion 473 and base portion 474 are support portions for movably supporting the driving force receiving portion.

[0259] The flange member 470 is a driving force receiving member for receiving the driving force from the main body driving shaft 101 via a driving force receiving portion provided on the engagement portion 473 .

[0260] Backup member 434 is provided with backup portion 434a, abutment portion 434b, and press-fit portion 434c. Backup portion 434a is assembled into the gap between engagement portion 473 and alignment portion 476, on the upstream side in the rotation direction of engagement portion 473, and has a shape that prevents engagement portion 473 and base portion 274 from tilting. Abutment portion 434b has a shape that a hemispherical shape 101c, which is a hemispherical shape at the tip of main body drive shaft 101, abuts against when drive of main body drive shaft 101 is transmitted to coupling member 428.

[0261] The press-fit portion 434c has a shape for being press-fitted into the attachment portion 472 of the flange member 470, thereby fixing the backup member 434 to the flange member 470.

[0262] (Explanation about flange parts) The flange member 470 will be described with reference to FIGS.

[0263] 32, the mounting portion 472 of the flange member 470 has hook portions 472b shaped to mount the backup member 434 to the flange member 470. The hook portions 472b protrude from an inner peripheral surface 472h of the mounting portion 472, and as shown in Fig. 31, a plurality of hook portions 472b are arranged in different phases in the circumferential direction of the flange member 470 from the base portion 474 and the engaging portion 473. In this embodiment, three hook portions 472b are arranged at equal intervals (120° intervals, approximately equal intervals) in the circumferential direction of the flange member 470.

[0264] As shown in FIG. 32, the hook portion 472b has a surface on the Z1 direction side that is approximately perpendicular to the Z axis, and a tapered shape on the Z2 direction side that is used when assembling the backup member 434.

[0265] When the aligning portion 476 is viewed along the Z direction, it has a hole shape 476d at the attachment portion 472 and within a range of about 1 mm around the attachment portion 472 (shown in FIGS. 31 and 32).

[0266] By providing hole shape 476d and providing a gap in a region of about 1 mm around mounting portion 472, flange member 470 can be produced using a simple mold.

[0267] 31 and 33, the alignment portion 476 has a receiving surface 476c. The backup portion 434a of the backup member 434 is sandwiched between a sandwiching surface 473g, which is a portion of the engagement portion 473 that is radially outer than the shaft portion 101f of the main body drive shaft 101, and the receiving surface 476c. The sandwiching surface 473g and the receiving surface 476c are substantially parallel to each other.

[0268] As shown in FIG. 33, the centering portion 476 has a rib 476e that is approximately perpendicular to the receiving surface 476c and whose extension passes through the end of the clamping surface 473g on the shaft portion 101f side.

[0269] (Explanation regarding backup components) The backup member 434 will be described with reference to FIGS.

[0270] The backup member 434 has a backup portion 434a, an abutting portion 434b, and a press-fit portion 434c.

[0271] As shown in Fig. 30, the backup portion 434a is disposed so as to be assembled into the gap between the clamping surface 473g of each engaging portion 473 and the receiving surface 476c. The thickness of the backup portion 434a is set to be approximately the same as the gap between the surface 473g and the receiving surface 476c. As shown in Fig. 34, the backup portion 434a is disposed so that the circle connecting the ridge lines on the clamping surface 473g side has the same center as the press-fit portion 434c, and the diameter D8 of the circle is approximately the same as the outer diameter D7 of the radial positioning portion 476a.

[0272] Similar to the abutment portion 76b of Example 1, the abutment portion 434b is positioned so that when it abuts against the hemispherical shape 101c, the center 101h of the hemispherical shape 101c of the main body drive shaft 101 is within the range of the driving force receiving surface 473a (shown in Figure 35).

[0273] The press-fit portion 434c is press-fitted and assembled into the inner circumferential cylinder 472h of the attachment portion 472 of the flange member 470. As shown in Fig. 35, the thickness of the press-fit portion 434c in the Z direction is set to be approximately the same as the gap between the vertical surface on the Z1 direction side of the hook portion 472b and the alignment portion 476.

[0274] The backup member 434 having the above-described shape is assembled to the flange member 470 from the Z2 direction to the Z1 direction to form the coupling member 428 (see FIG. 36).

[0275] [Coupling member driven by main body drive shaft] The transmission of rotational drive from the main body drive shaft 101 to the coupling member 428 will be described with reference to FIG.

[0276] When the driving force receiving surface 473a of the coupling member 428 abuts against the main body drive transmission surface 101b, the cleaning blade 26, the charging roller 22, etc. apply a load to the photosensitive drum unit 430. That is, the driving force receiving surface 473a rotates integrally with the drive transmission surface 101b while receiving the load (driving force) F1.

[0277] When this driving force F1 is received by driving force receiving surface 473a, as shown in FIG. 37, the driving force F1 is transmitted to clamping surface 473g of engagement portion 473, which is on the opposite side of driving force receiving surface 473a. Because engagement portion 473 is backed up by mounting portion 472 via backup portion 434a, receiving surface 476c, and rib 476e, engagement portion 473 is hardly deformed downstream in the rotation direction. As a result, driving force receiving surface 473a can be stably abutted against main body driving force receiving surface 101a, and photosensitive drum unit 430 can be pulled toward bearing portion 101d of main body drive shaft 101. Furthermore, even if load F fluctuates, engagement portion 473 is backed up as described above and therefore hardly deforms. Therefore, the amount of rotation of photosensitive drum 1 remains almost unchanged, maintaining the quality of image quality.

[0278] That is, the backup portion 434b is a member that restricts the movement of the driving force receiving portion provided on the engaging portion 474 in the rotation direction of the drum unit (the circumferential direction of the coupling member).

[0279] In this embodiment, the engaging portion 473 (and the driving force receiving portion provided on the engaging portion 473) is provided inside the cylindrical portion 471 in the Z direction (see FIG. 35). In other words, the engaging portion 473 is located outside the photosensitive drum 1 in the Z direction. However, as shown in FIG. 38, the driving force receiving surface 473a (engaging portion 473) may be provided inside the mounting portion 72 in the Z direction, as in the third embodiment. In this case, the photosensitive drum 1 can be disposed closer to the main body drive shaft 101, as in the third embodiment. This contributes to the miniaturization of the cartridge 7 and the image forming apparatus 100 in the Z direction. Alternatively, the base and the engaging portion 473 can be protected by disposing a part of the base or the engaging portion 473 on the far side of the photosensitive drum 1.

[0280] <Example 5> The fifth embodiment will be described with reference to FIGS.

[0281] This embodiment is characterized in that the support portions (engagement portion 573, base portion 574) that movably support the driving force receiving portion 573a extend at least in the circumferential direction of the coupling member 528.

[0282] Elements corresponding to those in the previous embodiment (especially embodiment 2) are given the same names, and explanations of the same points as the previous elements may be omitted. The following explanations will focus on the points that are different from the previous elements.

[0283] FIG. 39 is a cross-sectional perspective view of a coupling member 528 according to the fifth embodiment.

[0284] FIG. 40 is a cross-sectional view of a coupling member 528 according to the fifth embodiment, taken along a direction perpendicular to the rotation axis at a position passing through a drive transmission part 573.

[0285] FIG. 41 is a cross-sectional view of the coupling member 528 and the main body drive shaft 101 according to the fifth embodiment, taken in a direction perpendicular to the rotation axis at a position passing through the engaging portion 573.

[0286] FIG. 42 explains the configuration of a mold used when molding a flange member 570 according to the fifth embodiment.

[0287] FIG. 43 is a perspective view of an aligning member 533 according to the fifth embodiment.

[0288] FIG. 44 is a view of the aligning member 533 according to the fifth embodiment as viewed from the outside in the Z direction.

[0289] FIG. 45 is a cross-sectional view of a coupling member 528 according to the fifth embodiment.

[0290] FIG. 46 is a view of a flange member 570 according to the fifth embodiment as viewed from the outside in the Z direction.

[0291] FIG. 47 is a diagram illustrating the assembly of a coupling member 528 according to the fifth embodiment.

[0292] FIG. 48 is a view of the aligning member 533 according to the fifth embodiment as viewed from the inside in the Z direction.

[0293] FIG. 49 is a cross-sectional view for explaining the mounting operation of the coupling member 528 to the main body drive shaft 101 according to the fifth embodiment.

[0294] FIG. 50 is a cross-sectional view for explaining the mounting operation of the coupling member 528 to the main body drive shaft 101 according to the fifth embodiment.

[0295] FIG. 51 is a cross-sectional view illustrating the transmission of drive power from the main body drive shaft 101 to the coupling member 528 according to the fifth embodiment.

[0296] FIG. 52 is a view of a flange member 570 according to the fifth embodiment as viewed from the inside in the Z direction.

[0297] FIG. 53 is a cross-sectional view illustrating the transmission of drive power from the main body drive shaft 101 to the coupling member 528 according to the fifth embodiment.

[0298] FIG. 54 is an explanatory cross-sectional view when the positions of the main body drive shaft 101 and the coupling member 528 according to the fifth embodiment are misaligned due to component tolerances.

[0299] FIG. 55 is a cross-sectional view for explaining the operation of removing the coupling member 528 from the main body drive shaft 101 according to the fifth embodiment.

[0300] FIG. 56 is a cross-sectional view illustrating drive transmission when the diameter of the winding portion 574b of the base portion 574 of the coupling member 528 according to the fifth embodiment is larger than the diameter of the shaft portion 101f of the main body drive shaft 101.

[0301] FIG. 57 is a cross-sectional view illustrating drive transmission when the winding portion 574b of the base portion 574 of the coupling member 528 according to the fifth embodiment has a diameter smaller than that of the shaft portion 101f of the main body drive shaft 101.

[0302] As will be described in detail later, in this embodiment, as shown in Figure 39, coupling member 528 is made up of flange member (driving force receiving member) 570 and alignment member (positioning member) 533 having an inverted cone shape 533a. Base 574 is arranged to overlap with driving force receiving surface (driving force receiving portion) 573a in the Z direction. In other words, when base 574 and driving force receiving surface 573a are projected onto the axis of the drum unit, at least a portion of their projected areas overlap.

[0303] Further, the driving force receiving surface (driving force receiving portion) 573a and the root portion 574a of the base portion 574 are configured to be disposed on the inner circumferential surface 571b of the cylindrical portion 571. That is, the root portion 574a is located outside the photosensitive drum 1 in the Z direction.

[0304] As shown in FIG. 45, the root portion 574a of the base portion 574 is disposed so as to overlap the entire area of ​​the driving force receiving surface 573a in the Z direction.

[0305] The root portion 574a is the rear end (the outer end in the radial direction) of the base portion 574, and is a connecting portion where the base portion 574 is connected to the flange member 570 (the inner peripheral surface 571b). The root portion 574a is also a supported portion of the base portion 574. The flange member 570 supports the root portion 574a of the base portion 574.

[0306] (Explanation about flange parts) 46, a plurality of engagement portions 573 and a plurality of base portions 574 are symmetrically arranged on flange member 570. That is, engagement portions 573 are arranged in three locations at equal intervals (120° intervals, approximately equal intervals) around the circumference of flange member 570. Similarly, base portions 574 are also arranged in three locations at equal intervals around the circumference of flange member 570.

[0307] Engagement portion 573 is a protrusion (convex portion, protruding portion) that protrudes at least inward in the radial direction (radial direction of the drum unit) of coupling member 528. Engagement portion 573 is disposed at the tip of base portion 574 and is supported by base portion 574.

[0308] The base portion 574 is an extending portion (extending portion, extended portion) that extends in the circumferential direction of the coupling member 528. The extending direction of the base portion 574 intersects with the protruding direction of the engaging portion 573. More specifically, the base portion 574 extends at least in the circumferential direction of the coupling member 528 (flange member 570). In other words, the base portion 574 extends at least in the rotational direction of the drum unit.

[0309] Base portion 574 and engagement portion 573 are supporting portions for movably supporting driving force receiving portion 573a. Base portion 574 has a deforming portion (deforming portion, flexible portion) that elastically deforms to move driving force receiving portion 573a. Base portion 574 is configured to deform around its fixed end as a fulcrum.

[0310] The engaging portion 573 is configured to be able to engage with the main body drive shaft 101. The engaging portion 573 is provided with a driving force receiving surface (driving force receiving portion) 573a that can receive a driving force (rotational force) for rotating the photosensitive drum 1.

[0311] The engagement portion 573 is configured so that its protrusion (the distance it protrudes from the surface of the base portion 574) is 1.2 mm when measured radially. In order to engage with the drive transmission groove of the main body drive shaft 101, the protrusion of the engagement portion 573 is preferably 0.6 mm or more when measured radially, and more preferably 1.0 mm or more. It is even more preferable that the protrusion measured radially is 1.2 mm or more, as in this embodiment.

[0312] In a configuration in which the entire protruding portion of engagement portion 573 engages with the main body drive transmission groove, base driving force receiving portion 573a needs to be retracted by an amount equal to or greater than the protruding amount of engagement portion 573. Therefore, in this embodiment, driving force receiving portion 573a can move at least 1.2 mm in the radial direction.

[0313] Furthermore, the preferred amount of movement of driving force receiving portion 573a corresponds to the preferred amount of protrusion of engaging portion 573. In other words, the amount of movement of driving force receiving portion 573a measured along the radial direction is desirably 0.6 mm or more, more preferably 1.0 mm or more, and even more preferably 1.2 mm or more.

[0314] Engagement portion 573 and base portion 574 are supporting portions that movably support driving force receiving surface 573a. Base portion 574 is a deformation portion that can be elastically deformed (elastic deformation portion, flexible portion), and deformation of base portion 574 causes movement of driving force receiving surface 573a.

[0315] The driving force receiving surface 573a is a driving force transmitting portion (driving force transmitting portion) to which a driving force (rotational force) is transmitted from the outside of the drum unit (outside of the process cartridge), that is, from the main body of the apparatus.

[0316] The base portion 574 extends in a direction different from the protruding direction of the engaging portion 573 (a direction intersecting the protruding direction). In other words, the base portion 574 extends at least in the circumferential direction (rotational direction) of the flange member 570. More specifically, the base portion 574 extends from the flange member 570 toward the downstream side in the rotational direction. The tip of the base portion 574 is the end portion on the downstream side in the rotational direction. Furthermore, the rear end (root portion 574a) of the base portion 574 is the end portion on the upstream side in the rotational direction. Furthermore, the tip of the base portion 574 is located radially inward from the rear end. In other words, the tip of the base portion 574 is the end portion on the radially inner side, and the rear end of the base (root portion 574a) is the end portion on the radially outer side.

[0317] An engaging portion 573 is provided on the downstream side (tip side) of base portion 574. An upstream end portion (rear end) of base portion 574 is a connecting portion that connects to flange member 570. The rear end of base portion 574 is a supported portion that is supported by flange member 570, and is root portion 574a of base portion 574.

[0318] The direction in which base 574 extends is substantially perpendicular to the rotation axis of flange member 570 (drum unit). In other words, the straight line connecting the front and rear ends of base 574 is at an angle of approximately 90° to the axis. In other words, both the front and rear ends of base 574 are located on the same cross section parallel to the rotation axis of flange member 570.

[0319] 50, each of the three base portions 574 is arranged from its leading end to its trailing end on the same cross section perpendicular to the axis of the flange member 570. The three engaging portions 573 and the three root portions 574a are all arranged on the same cross section. In other words, the multiple engaging portions 573 and the multiple base portions 574 are at approximately the same position in the Z direction.

[0320] As shown in FIG. 40(a), the base 574 has a root portion 574a, a winding portion 574b, and a straight portion 574c that linearly connects the root portion 574a and the winding portion 574b. The root portion 574a is the portion (connection portion) where the inner diameter portion (inner surface, inner periphery) of the flange member 570 and the base 574 connect. The straight portion 574c has a substantially straight shape (substantially a flat plate shape). The winding portion 574b is the portion that winds around the main body drive shaft 101. That is, when the flange member 570 receives a driving force (rotational force) from the main body drive shaft 101 via the engagement portion 573, the winding portion 574b winds around the main body drive shaft 101 and comes into contact with the main body drive shaft 101. The winding portion 574b has a curved surface (a bow-shaped surface). The winding portion 574b is curved to follow the shape of the main body drive shaft 101. In other words, the winding portion 574b is curved so as to follow the circumferential direction (rotational direction) of the coupling member 528. In yet another way, the winding portion 574b is a curved surface that faces radially inward (toward the axis of the coupling member) and is recessed radially outward.

[0321] The winding portion 574b is disposed on the side facing the driving force receiving surface 573a, and the driving force receiving surface 573a and the winding portion 574b form an acute angle.

[0322] As described above, the engaging portion 573 is provided at the tip of the base portion 574. In other words, the base portion 574 is a portion that supports the engaging portion 573. As in each of the above-described embodiments, the base portion 574 can be deformed to move the engaging portion 573 in the radial direction of the flange member 570.

[0323] The resin forming base 574 and engaging portion 573 is integral with the resin forming flange member 570. However, the present invention is not limited to this configuration. Engaging portion 573 may be formed from a different material from base 574 and may be bonded to the tip of base 574. Similarly, base 574 may be formed from a different material from the other portions of flange member 570, or base 574 may be configured to be detachable from flange member 570.

[0324] Furthermore, in order to increase the strength of base 574, metal may be disposed inside the resin that forms base 574. Figure 50 and other figures show a configuration in which a plate-shaped metal is disposed inside the resin. This type of configuration will be described separately using another embodiment (see Figure 65 and other figures) that will be described later.

[0325] The width of the base 574 in the Z direction is equal to or greater than the width of the driving force receiving surface 573a in the Z direction.

[0326] Furthermore, although the effect will be described later, it is desirable that the length of a perpendicular line drawn from the rotation center (rotation axis) of flange member 570 to the surface of winding portion 574b be approximately the same as or larger than the radius of shaft portion 101f of main body drive shaft 101. In other words, when flange member 570 is projected onto a plane perpendicular to the rotation axis of flange member 570, it is desirable that radius R1 of the arc forming the inner diameter of winding portion 574b on that plane (projection plane) be approximately the same as radius R2 of shaft portion 101f, or that R1 be larger than R2.

[0327] 40(a), straight portion 574c has a shape that extends in the tangential direction of the inner diameter of winding portion 574b. In other words, straight portion 574c is a flat plate that is integrated with the arc-shaped end of winding portion 574b, and is joined to the inner diameter portion of flange member 570 at root portion 574a. The tangent to the end of winding portion 574b is approximately parallel to straight portion 574c.

[0328] Here, as shown in FIG. 40(c), the distance from the inner diameter end 573b of the driving force receiving surface 573a to the inner diameter of the winding portion 574b in the radial direction of the flange member 570 is defined as "H1."

[0329] Furthermore, the distance from the outer shape of engaging portion 573 to the inner diameter of cylindrical portion 571 in the radial direction of flange member 570 is defined as "H2." At this time, engaging portion 573 and base portion 574 are configured to have a relationship of "H1"≦"H2." By employing such a configuration (shape), the following effects can be obtained.

[0330] Even when engaging portion 573 moves inner diameter end 573b of driving force receiving surface 573a radially outward by H1, it is possible to prevent interference between driving force receiving surface 573 and inner circumferential surface 571b of cylindrical portion 571. When engaging portion 573 comes into contact with main body drive shaft 101 during the process of mounting coupling member 528 to the main body drive shaft, engaging portion 573 can reliably move radially outward to retract.

[0331] As described above, the length of the perpendicular line drawn from the rotation center of flange member 570 to the surface of winding portion 574b is approximately the same as the radius of shaft portion 101f of main body drive shaft 101. As a result, the outer shape of engagement portion 573 does not interfere with mounting portion 572, and inner diameter end 573b of driving force receiving surface 573a can move radially outward to shaft portion 101f.

[0332] 41, the radial thickness of winding 574b on the driving force receiving surface 573a side is defined as tip-side thickness (thickness on the driving force receiving surface side) 574k, and the thickness of straight portion 574c is defined as straight portion thickness 574l (rear-end side thickness). In this case, by creating the shape of each portion so that the relationship of "tip-side thickness 574k"≧"straight portion thickness 574l" is satisfied, the following effects can be obtained.

[0333] As shown in FIG. 41, when the driving force receiving surface 573a receives a rotational force F1 from the main body drive transmission surface 101b, the engaging portion 573 receives a moment M that tends to deform radially outward from the joint between the engaging portion 573 and the base portion 574. The deformation of the engaging portion 573 due to this moment M can be reduced by increasing the tip-end thickness 574k that supports the outer end 573c, which is the starting point of the deformation. On the other hand, if the straight portion thickness 574l is also increased, the load generated when the coupling member 528 is attached to the main body drive shaft 101 increases. In other words, the load required to retract the base portion 574 radially outward increases, making it difficult for the user to attach the cartridge.

[0334] Therefore, by making the relationship of tip end side thickness 574k≧straight portion thickness 574l, it is possible to reduce deformation of engaging portion 573 and also to achieve good cartridge mountability, which is more preferable.

[0335] 41, the engaging portion 573 can be retracted toward the outside in the radial direction of the coupling member 528 (the radial direction of the photosensitive drum unit 30). The driving force receiving surface 573a provided on the engaging portion 573 is inclined with respect to the direction of movement of the engaging portion 573. In the cross-sectional view shown in FIG. 41, line B3 is a line extending in the direction in which the engaging portion 573 moves when retracted. line B4 is a line along the driving force receiving surface 573a. It can be seen that line B3 and line B4 intersect. As a result, when the driving force receiving surface 573a is in contact with the drive transmission groove 101a, the driving force receiving surface 573a bites into the drive transmission groove 101a, making it difficult for the engaging portion 573 to retract from the drive transmission groove 101a. In other words, the engagement state between the engaging portion 573 and the drive transmission groove 101a is stabilized.

[0336] In particular, driving force receiving surface 573a is inclined with respect to the movement direction (straight line B3) of engaging portion 573 so that the inner diameter side (tip side) is positioned more upstream in the rotation direction of coupling member 528 than the outer diameter side (root side). Therefore, when coupling member 528 (photosensitive drum unit 30) rotates, the force received from driving force receiving surface 573 acts in a direction that causes engaging portion 573 to engage with main body drive transmission groove 101a. The engagement state between engaging portion 573 and main body drive transmission groove 101a is stabilized, and disengagement between engaging portion 573 and main body drive transmission groove 101a is prevented.

[0337] Figure 40(a) is a view of flange member 570 viewed along the Z direction. As shown in Figure 40(a), when viewed along the Z direction, root portion 574a is arranged on the upstream side in the rotation direction of flange member 570 with respect to a line drawn from inner diameter end 573b of driving force receiving surface 573a in a direction perpendicular to the driving force receiving surface.

[0338] Further, when viewed along the Z direction, of the ridge lines formed by straight portion 574c and inner circumferential surface 571b of cylindrical portion 571, the ridge line on the driving force receiving surface 573a side is defined as inner ridge line 574d, and the ridge line on the opposite side of driving force receiving surface 573a is defined as outer ridge line 574e. As shown in FIG. 40(b), inner ridge line 574d is connected to inner circumferential surface 571b of cylindrical portion 571 by a circular arc that is larger than outer ridge line 574e.

[0339] This is because it is desirable that the joint surface where base portion 574 and inner circumferential surface 571b of cylindrical portion 571 are joined be as large as possible. This is because, when driving force receiving surface 573a receives a driving force, the force acting on inner circumferential surface 571b of cylindrical portion 571 to which base portion 574a is connected can be dispersed, and deformation of cylindrical portion 571 can be kept small. As a result, even if the load received by photosensitive drum unit 30 changes, the amount of deformation of cylindrical portion 571 is small, so the effect of deformation on the rotation of photosensitive drum unit 30 can be kept small. It is desirable to make the joint surface where base portion 574 and cylindrical portion 571 are joined as large as possible.

[0340] As shown in Figure 40(b), when viewed from the Z direction, the angle I of the angle formed by the straight line passing through the base portion 574a and the straight portion 574a among the tangents to the inner diameter of the mounting portion 572 on the outer ridge line 574e side is an acute angle.

[0341] Starting point 574f of elastic deformation of base 574 is near the point where the influence of the arc of the ridge formed by straight portion 574c and cylindrical portion 571 disappears. In other words, if inner ridge 574d and outer ridge 574e are arcs of the same size, angle I is an acute angle. Therefore, starting point 574f is near the intersection of the center line of straight portion 574c and a line drawn perpendicular to the center line of straight portion 574c from the end of the ridge on the inner diameter side of outer ridge 574e.

[0342] If the ridgeline on the side of outer ridgeline 574e is made gentler, angle I becomes acute on the side of outer ridgeline 574e, and the position of starting point 574f of elastic deformation shifts to starting point 574f' when the arc is enlarged. This shortens the length over which base 574 can elastically deform, and the fit of coupling member 528 to main body drive shaft 101 deteriorates.

[0343] The intersection point between a straight line extending from starting point 574f and perpendicular to straight portion 574c and the inside of straight portion 574c is defined as intersection point 574m. Even if the arc of inner ridgeline 574d is increased to a size that passes through intersection point 574m, the range of influence of the arc of the ridgeline formed by straight portion 574c and mounting portion 572 on straight portion 574c does not change. In other words, even if the arc of inner ridgeline 574d is increased to the extent that it passes through intersection point 574m, it is possible to ensure a large joint surface where base portion 574 and cylindrical portion 571 are joined without reducing the mountability of coupling member 528 to main body drive shaft 101.

[0344] (Explanation of manufacturing method) The configuration of the mold used to mold the flange member 570 will be described with reference to FIG.

[0345] FIG. 42 is an explanatory cross-sectional view showing a state in which the flange member 570 is molded in the mold.

[0346] Flange member 570 has a shape in which collar portion 575 protrudes outward most in the radial direction. When molding such a shape, it is preferable to use a mold as shown in FIG.

[0347] Specifically, as shown in the figure, the mold is composed of two dies: a left-hand die (cylinder-side die 560) and a right-hand die (attachment-side die 561). By mating the left and right dies, a space (mold cavity, hollow portion) of the same shape as the molded product is formed. A material is poured into this space and solidified within the mold to form the flange member 570. The mold is configured such that a die split 562 (a surface for splitting the die, a surface for mating the die), where the left and right dies are mated, is located near the space that forms the flange portion 575. The cylinder-side die 560 is shaped to have a space for molding the outer periphery of the cylindrical portion 571. Similarly, the attachment-side die 561 is shaped to have a space for molding the attachment portion 572.

[0348] When forming the coupling member 570 using such a mold, it is preferable to use a thermoplastic resin from the viewpoint of mass production. Specifically, materials such as POM and PPS are considered to be suitable. However, other materials may be selected as appropriate to meet requirements such as strength. Specifically, it is also possible to use a thermosetting resin or a metal material.

[0349] As in the first embodiment, the engaging portion 573 has an insertion taper 573d at one end in the Z direction and a removal taper 573e at the other end. Therefore, it is difficult to position the mold half 562 on either end face of the engaging portion 573 in the Z direction.

[0350] This is because when a mold that is separated into two pieces is used, if mold half 562 of the mold is positioned on the end face of engagement portion 573, it becomes difficult to remove molded flange member 570 from the mold. In other words, one of the two molds cannot move relative to flange member 570.

[0351] Similarly, the driving force receiving surface 573a has a shape in which the outer side (Z1 direction side) of the photosensitive drum unit 30 is twisted upstream in the rotation direction relative to the inner side (Z2 direction side). For this reason, the shape forming the driving force receiving surface 573a is provided on the attachment portion side mold 561 side. This is because if the driving force receiving surface 573a were formed on the left side (cylinder side mold 560), the cylinder side mold 560 would not be able to be removed from the driving force receiving surface 573a.

[0352] Making the mold split 562 as straight as possible makes it easier to manufacture the mold, and as a result, it becomes possible to manufacture with high precision the mold split 562. Therefore, if the mold split 562 is made as straight as possible, the possibility of resin leakage or the like occurring can be reduced.

[0353] In order to make the mold split 562 of the engagement portion 573 straight, it is necessary to position the driving force receiving surface 573a at least further back than the insertion taper 573d in the photosensitive drum unit 30. Therefore, in this embodiment, the end of the insertion taper 573d and the end of the driving force receiving surface 573a are positioned at the same position in the Z direction.

[0354] In this embodiment, the inner diameter of the portion of flange member 570 where root portion 574a is disposed is approximately the same as the inner diameter of other portions. Specifically, the inner diameter of the portion where root portion 574a is disposed is approximately the same as the inner diameter of inner circumferential surface 571b of the cylindrical portion. Also, the inner diameter of the inner circumferential surface of mounting portion 572 and the inner diameter of the portion where root portion 574a is disposed are approximately the same dimension.

[0355] Furthermore, when flange member 570 is viewed along the Z direction, if a different shape (such as a protrusion) is arranged in a portion that overlaps base 574, the different shape will be connected to base 574 when flange member 570 is molded in a mold. When base 574 is connected to the different shape, elastic deformation of base 574 is hindered.

[0356] Therefore, in the flange member of this embodiment, on a projection plane obtained by projecting flange member 570 onto a plane perpendicular to the rotation axis (Z direction), there is no portion of flange member 570 that overlaps with base portion 574. Similarly, there is no portion that overlaps with driving force receiving portion 573.

[0357] (Explanation about alignment components) Next, the configuration of the alignment member (positioning member) 533 will be described with reference to FIGS.

[0358] In the first embodiment, the main body drive shaft 101 and the coupling member 28 are aligned by the radial positioning portion 76a, and the Z direction positioning is performed by the abutting portion 76b (see FIGS. 14 and 15). The radial positioning portion 76a is positioned so as to overlap the engaging portion 73 in the Z direction. In other words, when the radial positioning portion 76a and the engaging portion 573 are projected onto the rotation axis of the coupling member 28, their projected areas at least partially overlap each other on the rotation axis.

[0359] In contrast to this, in the present embodiment, the base 574 is arranged to overlap the driving force receiving surface 573a in the Z direction. In other words, the base 574 and the engaging portion 573 are arranged to overlap when projected onto the rotation axis of the coupling member 528. When the base 574 and the engaging portion 573 are arranged in this manner, it is difficult to arrange a radial positioning portion such as that in the first embodiment to overlap the engaging portion 573 in the Z axis direction.

[0360] Therefore, in this embodiment, instead of a configuration like the radial positioning portion 76a disclosed in the first embodiment, an alignment member (positioning member) 533 having the above-mentioned inverted cone shape 533a is employed. This alignment member 533 is used to position the coupling member 528 with respect to the main body drive shaft 101. The inverted cone shape 533a is a recess that is approximately conical. The detailed shape of the alignment member 533 will be described below.

[0361] 43 and 44, the alignment member 533 has an inverted cone shape 533a, an engaging portion 533b, a retaining portion 533c, and a protrusion 533d that aligns the phase with the flange member 570. The engaging portion 533b is engaged with the flange member 570. The retaining portion 533c has the function of preventing the alignment member 533 from coming off the flange member 570.

[0362] 45, the inverted cone shape 533a is disposed inside (on the Z2 direction side) the photosensitive drum unit 30 relative to the engagement portion 573. Furthermore, when the flange member 570 and the alignment member 533 are viewed along the Z direction, the flange member 570 and the alignment member 533 are assembled so that the center of the inverted cone shape 533a and the center of the photosensitive drum 1 coincide with each other.

[0363] The inverted cone shape 533a has a contact portion 533e that contacts the hemispherical shape 101c at the tip of the main body drive shaft 101 when the photosensitive drum 1 is driven to rotate.

[0364] As shown in Figure 45, the alignment member 533 is attached to the flange member 570 so that the center 101h of the hemispherical shape 101c of the main body drive shaft 101 is within the range of the driving force receiving surface 573a, with the abutment portion 533e abutting against the hemispherical shape 101c in the Z direction.

[0365] As shown in FIG. 45, the fitting portion 533b is disposed inside (on the Z2 direction side) the photosensitive drum unit 30 relative to the contact portion 533e.

[0366] Furthermore, the flange member 570 has a mating portion 572a at a position corresponding to the mating portion 533b. As a result, the center of the inverted cone shape 533a and the center of the photosensitive drum 1 can be aligned with high precision.

[0367] 43, the retaining portion 533c has a snap-fit ​​shape and is shaped to prevent the alignment member 533 from falling off from the flange member 570. In other words, the retaining portion 533c is a connecting portion that connects the alignment member 533 to the flange member 570.

[0368] 45, when the alignment member 533 is attached to the flange member 570, the retaining portion 533c is disposed inside (on the Z2 direction side) the photosensitive drum unit 30 relative to the engaging portion 573 (driving force receiving portion 573a). Therefore, even if the base portion 574 of the flange member 570 is deformed radially outward, the retaining portion 533c is configured not to prevent the radial deformation (movement) of the base portion 574. In other words, the engaging portion 573 does not come into contact with the retaining portion 533c when moving radially.

[0369] 45 and 46, flange member 570 has hook portion 572b corresponding to retaining portion 533c. Hook portion 572b is arranged in a portion that does not overlap with base portion 574 when viewed along the Z direction, as shown in FIG.

[0370] The hook portion 572b is disposed approximately midway between two base portions 574 that are disposed adjacent to each other in the circumferential direction. This ensures a gap between the base portion 574 and the hook portion 572b in the circumferential direction. In this embodiment, three hook portions 572b that engage with the retaining portions 533c are disposed midway between the base portions 574a.

[0371] 43 and 47, the convex portion 533d, which functions as an assembly guide, has a shape that protrudes radially outward from the fitting portion 533b. Therefore, it is possible to easily align the phase of the retaining portion 533c and the hook portion 572b when attaching the alignment member 533 to the flange member 570. The concave portion 533d is a phase determining portion that determines the phase (posture and position in the rotational direction) of the alignment member 533 relative to the flange member 570.

[0372] 47, the notch portion 572c is disposed at a position 90° apart from the crimping groove 572e in the circumferential direction. As in Example 1, the crimping groove 572e is disposed in two locations evenly spaced around the rotation axis of the coupling member 528. In other words, the notch portion 572c is disposed at the position furthest from each other, midway between the two crimping grooves 572e disposed at positions 180° apart in the circumferential direction of the flange member 570. This makes it possible to reduce the effect that the crimping groove e and the notch portion 572c have on the rigidity of the flange member 570.

[0373] 48, the alignment member 533 has an outer cylindrical rib 533f that forms the fitting portion 533b, and an inner cylindrical rib 533g on the back side of the outer end of the inverted cone shape 533a. The alignment member 533 also has a plurality of radial ribs 533i that connect the outer cylindrical rib 533f and the inner cylindrical rib 533g. Note that no ribs are arranged inside the inner cylindrical rib 533g.

[0374] By connecting the outer cylindrical rib 533f and the inner cylindrical rib 533g with the radial ribs 533i, it is possible to suppress deformation of the alignment member 533 when the alignment member 533 is press-fitted into the flange member 570. Furthermore, by not arranging a rib inside the inner cylindrical portion 533g, it is possible to suppress an increase in the thickness of the center of the conical shape 533a. This makes it possible to improve the dimensional accuracy of the inverted conical shape 533a, which affects the alignment function.

[0375] [Coupling member engagement process with main body drive shaft] Next, the process of engagement between the coupling member 528 and the main body drive shaft 101 will be described in detail.

[0376] Figure 49 is a cross-sectional view illustrating the mounting operation of the coupling member 28 to the main assembly drive shaft. Figure 49(a) illustrates a state in which the coupling member 28 begins to engage with the main assembly drive shaft 101. Figure 49(e) illustrates a state in which the cartridge 7 is mounted to the image forming apparatus main assembly 100A, the cartridge door 104 is closed, the front cartridge lower guide 109 is raised, and the cartridge 7 is positioned relative to the image forming apparatus main assembly 100A. Figures 49(b) to 49(d) are views illustrating the mounting process of the coupling member 528 to the main assembly drive shaft 101 between Figures 49(a) and 49(e). Note that the main assembly drive shaft 101 hangs downward in the direction of gravity at a small angle due to its own weight, as in Example 1.

[0377] 50 is a diagram for explaining a state in which the phase of main body drive transmission groove 101a and the phase of engagement portion 573 (driving force receiving surface 573a) do not match. In other words, Fig. 50 shows a state in which engagement portion 573 (driving force receiving surface 573a) does not fit inside main body drive transmission groove 101a, and the two are not engaged with each other.

[0378] As in Example 1, as shown in Figure 49(a), when the cartridge 7 is positioned relative to the image forming apparatus main body 100A (shown in Figure 49(e)), the coupling member 528 is inserted into the main body drive shaft 101 at an inclination of approximately 0.5 to 2 degrees.

[0379] As shown in FIG. 49(b), first, the tip of the inner peripheral surface 571b of the cylindrical portion 571 of the flange member 570 abuts against the rough guide portion 101g of the main body drive shaft 101. As shown in the figure, the main body drive shaft 101 is configured to be cantilevered at the bearing portion 101d. Therefore, the coupling 7 is inserted into the main body drive shaft 101 with the rough guide portion 101g of the main body drive shaft 101 in contact with the inner peripheral surface 571b of the coupling member 570. As in the first embodiment, the engaging portion 573 is positioned such that the length L2 of the driving force receiving surface 573 satisfies the relationship L1>L2, where L1 is the distance from the front end face of the cylindrical portion 571 to the front end face of the engaging portion 573 in the Z direction (shown in FIG. 45). Therefore, before the hemispherical shape 101c at the tip of the main body drive shaft 101 hits the engagement portion 573, the rough guide portion 101g of the main body drive shaft 101 fits along the inner peripheral surface 571b of the coupling member 570.

[0380] As a result, main body drive shaft 101 is guided relative to coupling member 528. Therefore, it is possible to prevent return ball shape 101c at the tip of main body drive shaft 101 from hitting an unexpected location on engaging portion 573 or base portion 574 and giving an impact to engaging portion 573 or base portion 574. In other words, engaging portion 573 and base portion 574 can be protected.

[0381] 49(c), when coupling member 528 is further inserted toward the back of main body drive shaft 101 from the position shown in FIG. 49(b), tapered insertion surface 573d of engagement portion 573 comes into contact with hemispherical shape 101c at the tip of main body drive shaft 101. Due to the inclined surface of tapered insertion surface 573d and the spherical shape of hemispherical shape 101c, main body drive shaft 101 is guided to approximately the center of the three engagement portions 573.

[0382] When the coupling member 528 is further inserted into the main body drive shaft 101, the base portion 574 elastically deforms radially outward so that the engaging portion 573 conforms to the hemispherical shape 101c. As a result, as shown in Figure 50(a), the engaging portion 573 moves (retreats) to the outer diameter of the shaft portion 101f of the main body drive shaft 101. This movement causes the coupling member 528 to be attached to the main body drive shaft 101 until the removal taper surface 573e of the engaging portion 573 is located further back in the Z direction than the main body-side removal taper 101i of the main body drive shaft 101, as shown in Figure 49(d).

[0383] Thereafter, as in the first embodiment, the cartridge 7 is lifted up so that the drum unit bearing member 39L of the cartridge 7 abuts against the front cartridge positioning portion 110. By lifting the cartridge 7, the cartridge 7 is positioned relative to the image forming apparatus main body 100A (as shown in FIG. 21(d)). This movement of the cartridge 7 eliminates the inclination of the coupling member 528, as shown in FIG. 49(e). In other words, the coupling member 528 and the drum unit are in a position where image formation is possible.

[0384] 50(b), when the main body drive shaft 101 rotates, the main body drive transmission groove 101a and the engaging portion 573 are in phase with each other. This releases the elastic deformation of the base 574, and a part of the engaging portion 573 enters the main body drive transmission groove 101a, thereby engaging the coupling member 528 and the main body drive shaft 101.

[0385] Note that, when the main body drive transmission groove 101a and the engaging portion 573 are in phase, the elastic deformation of the base portion 574 is at least partially released at the stage of Figure 49(d), resulting in the state of Figure 50(b). In other words, when the base portion 574 moves from the state shown in Figure 50(a) to the state shown in Figure 50(b), it deforms so as to move the engaging portion 573 radially inward. More strictly speaking, the state of the base portion 574, which had been deformed radially outward, is at least partially restored, causing the engaging portion 573 to move at least radially inward.

[0386] In this way, the base portion 574 causes the engaging portion 573 to enter the inside of the main body drive transmission groove 101 a, and the engaging portion 573 is engaged with the main body drive transmission groove 101 a of the main body drive shaft 101 .

[0387] [Coupling member driven by main body drive shaft] The transmission of rotational drive from the main body drive shaft 101 to the coupling member 528 will be described with reference to FIGS.

[0388] As described above, after the cartridge door 104 of the image forming apparatus main body 100A in which the cartridge 7 is installed is closed, the main body drive shaft 101 rotates. As a result, the phase of the engaging portion 573 and the phase of the main body drive transmission groove 101a match, resulting in the state shown in Figure 50(b). The main body drive shaft 101 is configured to be rotatable in the rotation direction during image formation and in the opposite direction.

[0389] As shown in Figure 50(b), when the main body drive shaft 101 further rotates counterclockwise, the main body drive transmission surface 101b comes into contact with the drive force receiving surface 573a as shown in Figure 51. As a result, the rotational drive force of the main body drive shaft 101 is transmitted to the photosensitive drum 1 via the coupling member 528.

[0390] Similar to the first embodiment, the driving force receiving surface 573a has a shape twisted about the center of the rotation axis of the flange member 570. The twisting direction is such that the outer side (Z1 direction side) of the driving force receiving surface 573a of the photosensitive drum unit 30 is disposed upstream in the rotation direction of the photosensitive drum 1 relative to the inner side (Z2 direction side) (shown in FIG. 52).

[0391] Note that a configuration having the same function as a twisted surface may be used as long as the rotational phases of the two points of contact with the drive shaft are different. For example, the driving force receiving surface 573a may have a shape in which the outer side (Z1 direction side) of the photosensitive drum unit 30 is disposed upstream of the inner side (Z2 direction side) of the photosensitive drum unit 30 in the rotational direction of the photosensitive drum 1. In other words, the straight line connecting the inner end and outer end of the cylinder along the cylinder axial direction of the engaging portion 573 is configured to intersect with the rotational axis of the cylinder.

[0392] By adopting such a shape, when the driving force receiving surface 573a receives a driving force, a force is generated in the photosensitive drum unit 30 that pulls the photosensitive drum unit 30 toward the bearing portion 101d of the main body driving shaft 101.

[0393] This force (force in the Z1 direction) causes inverted cone shape 533a of alignment member 533 to firmly contact hemispherical shape 101c at the tip of main body drive shaft 101. When inverted cone shape 533a comes into contact with hemispherical shape 101c, the radial position of the coupling member relative to main body drive shaft 101 is determined. Furthermore, the longitudinal position of coupling member 528 relative to main body drive shaft 101 is also determined. In other words, inverted cone shape 533a is a radial positioning portion (alignment portion) that determines the radial position of coupling member 528 (drum unit) relative to main body drive shaft 101. In addition, inverted cone shape 533a is also a longitudinal positioning portion (axial positioning portion) that determines the longitudinal position of coupling member 528 (drum unit) relative to main body drive shaft 101.

[0394] The radial and longitudinal positioning portions do not need to be conical recesses such as the inverted cone shape 533a. The radial and longitudinal positioning portions may have any shape as long as they can determine the position of the photosensitive drum unit 30 relative to the main body drive shaft 101 when they contact the tip (semi-circular shape 101c) of the main body drive shaft 101. For example, recesses (concave portions) that taper toward the bottom are preferred. A non-conical cone shape such as a pyramid (e.g., a square pyramid) can also be used. However, a conical recess symmetrical about the axis of the coupling member 528, such as the inverted cone shape 533a of this embodiment, can maintain the position of the coupling member 528 with particularly high precision.

[0395] Note that the inverted cone shape 533a may have any shape for the non-contact area as long as it has an area for contacting the main body drive shaft 101. For example, the inverted cone shape 533a, which is the part that does not contact the main body drive shaft 101, may be a recess with a bottom.

[0396] When the flange member 570 is viewed along the Z direction, the base portion 574a is disposed on the upstream side in the rotation direction of the flange member 570 with respect to a line drawn from the inner diameter end 573b of the driving force receiving surface 573a in a direction perpendicular to the driving force receiving surface 573a (see FIG. 40(a)). This makes it possible to obtain the effects described below.

[0397] 51, driving force F1 is divided into a component Fh parallel to a line connecting inner diameter end 573b of driving force receiving surface and root portion 574a of base portion 574, and a vertical component Fv. Vertical component Fv is a component that pulls engaging portion 573 and base portion 574 toward shaft portion 101f. In other words, component Fv generates a moment in base portion 574 that rotates base portion 574 counterclockwise around root portion 574a as a fulcrum. As a result, engaging portion 573 and base portion 574 are pulled toward shaft portion 101f.

[0398] 51, if a normal line perpendicular to driving force receiving surface 573a is extended from the tip of driving force receiving surface 573a, base 574 extends so as to cross this normal line. In other words, the fixed end of base 574 is disposed upstream of the normal line in the rotation direction of the coupling member. This arrangement is preferable because it generates a moment that causes base 574 to wrap around shaft portion 101f of main body drive shaft 101.

[0399] Since the main body drive shaft 101 is rotating, when the base 574 is retracted, the winding portion 574b winds around the shaft 101f. As a result, the contact area between the base 574 and the shaft 101f becomes larger than when the base 574 is not wound around the shaft 101f (shown in FIG. 50(b)).

[0400] As a result of winding portion 574b around shaft portion 101f, as shown in FIG. 53, base 574 receives rotational force Fc generated by driving force F1 at straight portion 574c. The rotational force Fc has a component perpendicular to straight portion 574c, and therefore a component in the direction in which straight portion 574c has the greatest rigidity. As a result, the amount of deformation of base 574 is kept small. Therefore, even if the load received by photosensitive drum unit 30 changes, the amount of deformation of base 574 is small, and therefore the effect of deformation on the rotation of photosensitive drum unit 30 can be kept small.

[0401] The radius R1 of the arc forming the inner diameter of the winding portion 574b is approximately the same as or larger than the radius R2 of the shaft portion 101f, as described above, and therefore the following effects can be obtained.

[0402] As described above, when driving force receiving surface 573a receives driving force from main body drive transmission surface 101b, base portion 574 is pulled into shaft portion 101f of main body drive shaft 101. As a result, winding portion 574b winds around shaft portion 101f. As winding portion 574b winds around shaft portion 101f, the rotational force of main body drive shaft 101 is received by straight portion 574c.

[0403] 56(a), consider the case where radius R1 of winding portion 574b is larger than radius R2 of shaft portion 101f. In this case, when engagement portion 573 is in phase with main body drive transmission groove 101a and is inserted into main body drive transmission groove 101a, a gap is generated between winding portion 573b and shaft portion 101f.

[0404] Thereafter, when the driving force receiving surface 573a abuts against the main body drive transmission surface 101b and receives a rotational force, a pulling force is applied from the root portion 574a of the base 574 as a starting point, and the winding portion 574b winds around the shaft portion 101f, as shown in Figure 56(b). This winding allows the slate portion 74c to receive the rotational force in substantially the same manner as when the radius of the winding portion 574b is the same as the radius of the shaft portion 101f.

[0405] In contrast, the case where radius R1 of winding portion 574b is smaller than radius R2 of shaft portion 101f will be described with reference to FIG. 57. As shown in FIG. 57(a), when engagement portion 573 is in phase with main body drive transmission groove 101a, base portion 574 is bent to a position where straight portion 574c abuts shaft portion 101f at abutment point 574n. At this time, a gap is generated between winding portion 574b and shaft portion 101f that becomes larger toward engagement portion 573. Thereafter, when driving force receiving surface 573a abuts main body drive transmission surface 101b and receives a rotational force, winding portion 574b is pulled in from abutment point 574n. However, the distance from abutment point 574n to driving force receiving surface 573a is shorter than the distance from base portion 574a to driving force receiving surface 573a. Therefore, the driving force F1 required for winding the winding portion 574b around the shaft portion 101f increases compared to the case where the radius of the winding portion 574b is larger than the radius of the shaft portion 101f.

[0406] Therefore, it is possible to wind the winding portion 574b around the shaft portion 101f with a lower driving force F1. It is more preferable that the radius R1 of the winding portion 574b is approximately the same as or larger than the radius R2 of the shaft portion 101f.

[0407] As described above, the inverted cone shape 533a of the alignment member 533 is positioned so that the center 101h of the hemispherical shape 101c is within the range of the driving force receiving surface 573a of the flange member 570 in the Z direction (see FIG. 45). When the engagement portion 573 and the center 101h are projected onto the axis of the drum unit, the center of the center 101h is positioned within the projected area of ​​the engagement portion 573. In FIG. 45, the projected area of ​​the engagement portion 573 is indicated by L2, and it can be seen that the center 101h is positioned within the area indicated by L2. Establishing such an arrangement provides the following effects.

[0408] The drum unit bearing member 39R and the drum unit bearing member 39L abut against the rear cartridge positioning portion 108 and the front cartridge positioning portion 110, respectively. This determines the position of the cartridge 7 relative to the image forming apparatus main body 100A. Here, the relative position of the main body drive shaft 101 and the coupling member 28 is affected by component tolerances. Specifically, the position is shifted due to the component tolerances from the drum unit bearing member 39R to the coupling member 28 and from the rear cartridge positioning portion 108 to the main body drive shaft 101.

[0409] As shown in FIG. 54, hemispherical shape 101c abuts against inverted cone shape 533a, resulting in a configuration in which bearing portion 101d and hemispherical shape 101c support the main body drive shaft 101. That is, when viewed from coupling member 528, main body drive shaft 101 tilts around center 101h of hemispherical shape 101c. The position that is the same as center 101h in the Z-axis direction is the position that is least affected by this tilt. Positioning drive force receiving surface 573a at the same position as center 101h in the Z-axis direction is the position that can minimize the effects of positional misalignment. In other words, this is the position where photosensitive drum 1 can be driven stably.

[0410] [Removing the coupling member from the drive shaft] The operation of removing the coupling member 528 from the main body drive shaft 101 will be described with reference to FIG.

[0411] 55(a), the driving force receiving surface 573a and the main body drive transmission surface 101b come into contact with each other when the rotation of the main body drive shaft 101 stops. In this state, a part of the engaging portion 573 is inserted into the main body drive transmission groove 101a.

[0412] When the cartridge door 104 is opened, the front cartridge lower guide 109 descends, and the drum unit bearing member 39L moves away from the front cartridge positioning portion 110 of the image forming apparatus main body 100A. At this time, the coupling member 528 and the main body drive shaft 101 are tilted by approximately 0.5 to 2 degrees with respect to the installation completion state (Z direction), as shown in Figure 55(b).

[0413] When removal of the cartridge 7 from the image forming apparatus main body 100A begins, the removal tapered surface 573e of the engaging portion 573 abuts against the main body-side removal taper 101i, as shown in Figure 55(c). When the removal tapered surface 573e abuts against the main body-side removal taper 101i, the base portion 574 begins to elastically deform, and the engaging portion 73 moves radially outward along the main body-side removal taper 101i.

[0414] 50(a), the base 574 further elastically deforms, and the engaging portion 573 moves to the outer diameter of the shaft portion 101f of the main body drive shaft 101. When the engaging portion 573 moves to the outer diameter of the shaft portion 101f, the coupling member 528 can be removed from the main body drive shaft 101, as shown in FIG. 55(d).

[0415] Furthermore, when the coupling member 528 is removed from the main body drive shaft 101, the elastic deformation of the base portion 574 is released, and the position of the engaging portion 573 also returns to the position before the elastic deformation, as shown in FIG. 55(e).

[0416] By the above operation, the coupling member 528 can be removed from the main body drive shaft 101.

[0417] As described above, by using coupling member 528 of this embodiment, it is possible to reduce deformation of drive transmission part 573 and base part 574 when drive force F1 is applied. As a result, even if the load applied to photosensitive drum unit 30 changes, the effect on the rotation of photosensitive drum unit 30 can be kept small.

[0418] In this embodiment, a coupling member 528, a flange member 570, and an alignment member 533 are combined. However, depending on the material and molding method selected, it does not have to be two bodies, and it may be one body, or it may be configured by combining three or more members.

[0419] Example 6 The sixth embodiment will be described with reference to FIGS.

[0420] The sixth embodiment is characterized in that the driving force receiving portion 673a and its support portion (base portion 674 and engagement portion 673) are disposed inside the photosensitive drum. This embodiment is also characterized in that the support portion extends at least in the circumferential direction of the coupling member 628, similar to the fifth embodiment.

[0421] Elements corresponding to those in the above-described embodiments (especially embodiment 5) are given the same names, and explanations of the same points as the above-described elements may be omitted. The following explanation will focus on the points that are different from the above-described elements.

[0422] FIG. 58 is a cross-sectional view of a coupling member 628 according to the sixth embodiment.

[0423] FIG. 59 is a cross-sectional view of a flange member 670 according to the sixth embodiment.

[0424] FIG. 60 is a view of a flange member 670 according to the sixth embodiment as viewed from the outside in the Z direction.

[0425] FIG. 61 is an explanatory cross-sectional view showing the positional relationship in the Z direction of each component of the cleaning unit according to the sixth embodiment.

[0426] FIG. 62 is a cross-sectional view for explaining the mold configuration of a flange member 670 according to the sixth embodiment.

[0427] FIG. 63 is a perspective view of an aligning member 633 according to the sixth embodiment.

[0428] FIG. 64 is a cross-sectional view for explaining the operation of attaching the coupling member 628 to the main body drive shaft 101 according to the sixth embodiment.

[0429] FIG. 65 is a cross-sectional view for explaining the operation of attaching the coupling member 628 to the main body drive shaft 101 according to the sixth embodiment.

[0430] FIG. 66 is a view of a flange member 670 according to the sixth embodiment as viewed from the inside in the Z direction.

[0431] FIG. 67 is a cross-sectional view illustrating the drive transmission from the main body drive shaft to the coupling member according to the sixth embodiment.

[0432] FIG. 68 is a cross-sectional view for explaining the operation of removing the coupling member 628 from the main body drive shaft 101 according to the sixth embodiment.

[0433] Figure 69 is a cross-sectional view illustrating a state in which the drive transmission from the main body drive shaft 101 to the coupling member 3628 becomes unstable after long-term storage in a state in which the engagement portion and the main body drive transmission groove are not in phase when the flange member is made using a material with large creep deformation.

[0434] FIG. 70 is an explanatory cross-sectional view of a die configuration for inserting a metal plate 635 into a flange member 670 according to the sixth embodiment.

[0435] FIG. 71 is a view of a flange member 670 according to the sixth embodiment as viewed from the outside in the Z direction.

[0436] FIG. 72 is a cross-sectional view of a flange member 670 according to the sixth embodiment.

[0437] FIG. 73 is a cross-sectional perspective view of a flange member 670 according to the sixth embodiment.

[0438] FIG. 74 is a partial cross-sectional view of a flange member 670 according to the sixth embodiment, cut along a straight portion notch 674g.

[0439] FIG. 75 is a partial cross-sectional view of a flange member 670 according to the sixth embodiment, cut along a notch 674h in the winding portion.

[0440] In the fifth embodiment, the driving force receiving surface 573a and the root portion 574a of the base portion 574 are configured to be disposed on the inner circumferential surface 571b of the cylindrical portion 571 in the Z direction. In contrast, although a detailed configuration will be described later, in the present embodiment, as shown in FIG. 59 , the driving force receiving surface 673a and the root portion 674a are disposed within the inner periphery 672h of the attachment portion 672, which is on the inside of the photosensitive drum 1 in the Z direction. In other words, the driving force receiving surface 673a and the root portion 674a are disposed on the rear side (Z2 direction side) of the end surface 675b of the flange portion 675 that abuts against the photosensitive drum 1 when the coupling member 628 is assembled to the photosensitive drum 1.

[0441] [Configuration of coupling components] As in the fifth embodiment, the coupling member 628 is configured as two bodies, combining a flange member 670 and an alignment member 633 (see FIG. 58). However, depending on the material and molding method selected, it does not have to be two bodies, and it may be configured as one body or by combining three or more members.

[0442] As in the previous embodiment, the coupling member 628 of this embodiment has a driving force receiving surface (driving force receiving portion) 673a for receiving a driving force from the outside (main body drive shaft 101). The driving force receiving portion is provided on a protruding portion (engaging portion 673), and this engaging portion 673 is supported by a base portion 674.

[0443] The engaging portion 673 and the base portion 674 are supporting portions that support the driving force receiving surface 673a. The base portion 674 is an extending portion (extending portion, extended portion) that extends in the circumferential direction of the coupling member 628. The engaging portion 673 is provided at the tip of the base portion 674.

[0444] In this embodiment, when the support portion (base portion 674 and engagement portion 673) and the photosensitive drum 1 are projected onto the axis of the coupling member 628, the entire projected area of ​​the support portion is included within the projected area of ​​the photosensitive drum 1. This will be explained below.

[0445] (Explanation about flange parts) As in the fifth embodiment, three engaging portions 673 are arranged at equal intervals (120° intervals, approximately equal intervals) around the circumference of the flange member 670. Similarly, three base portions 674 are also arranged at equal intervals around the circumference of the flange member (shown in FIG. 60).

[0446] As in the fifth embodiment, the base 674 has a root portion 674a, a winding portion 674b, and a straight portion 674c that linearly connects the root portion 674a and the winding portion 674b.

[0447] As described above, the driving force receiving surface 673a and the base portion 674a are disposed on the rear side (Z2 direction side) of the end face 675b of the flange portion 675 that abuts against the photosensitive drum 1 when the coupling member 628 is attached to the photosensitive drum 1 (as shown in FIG. 59). However, a part of the engaging portion 673 including the insertion tapered surface 673d may protrude forward (Z1 direction) from the end face 675b of the flange portion 675 that abuts against the photosensitive drum 1.

[0448] The arrangement of the driving force receiving surface 673a and other components of the cleaning unit 613 will be described with reference to FIG. 61. FIG. 61 is an explanatory cross-sectional view showing the arrangement of the components of the cleaning unit 613 in the Z direction. As described above, the opening 614b of the cleaning frame 614 prevents toner leakage in the rotation direction of the photosensitive drum 1 by the blade-shaped rubber 66a of the cleaning blade 66 and the blowout prevention sheet 626. The opening 614b also has end seal members 627 at both ends in the Z direction, and portions of the end seal members 627 abut against the blade-shaped rubber (elastic member) 66a in the Z direction, thereby tightly contacting the photosensitive drum 1 and preventing toner leakage. In the Z direction, the driving force receiving surface 673a is located closer to the user (in the Z1 direction) than the blade-shaped rubber 66a of the cleaning blade 66, and is positioned so that at least a portion of the end seal member 627 overlaps with it. In other words, when the driving force receiving surface 673a and the end seal member 627 are projected onto the axis of the drum unit, at least a part of the projected area of ​​the driving force receiving surface 673a and at least a part of the projected area of ​​the end seal member 627 overlap.

[0449] Also, similar to Example 5, driving force receiving surface 673a has a shape twisted about the center of the rotation axis of flange member 670. The twisting direction is such that the outer side (Z1 direction side) of driving force receiving surface 673a of photosensitive drum unit 30 is disposed upstream in the rotation direction of photosensitive drum 1 relative to the inner side (Z2 direction side), and the amount of twist along the rotation axis direction of photosensitive drum 1 is about 1° per 1 mm.

[0450] As in Example 5, the engagement portion 673 is positioned such that the length L2 of the driving force receiving surface 73 satisfies the relationship L1 > L2, where L1 is the distance from the front end face of the cylindrical portion 71 to the front end face of the engagement portion 673 in the Z direction.

[0451] (Explanation of manufacturing method) As in the fifth embodiment, when manufacturing by injection molding, it is preferable to use a mold consisting of two parts, a cylinder side mold 660 and a mounting portion side mold 661 (see FIG. 62).

[0452] As in the fifth embodiment, the end of the insertion taper 673 and the end of the driving force receiving surface 673a are positioned at the same position in the Z direction, and the mold split 662 at the engaging portion 673 is made straight.

[0453] Also, as in the fifth embodiment, the inner diameter of the portion where the base portion 674a of the flange member 670 is disposed is set to be approximately the same as the inner diameter of the other portions.

[0454] As in the fifth embodiment, when the flange member 670 is projected onto a plane perpendicular to the rotation axis (Z direction), the engaging portion 673 and the support 674 do not overlap with other portions (see FIG. 60).

[0455] (Explanation about alignment components) As in the fifth embodiment, the aligning member 633 has an inverted cone shape 633a, a press-fit portion 633b, a retaining portion 633c, and a protrusion 633d (shown in FIG. 63). The protrusion 633d is a portion for aligning the phases of the aligning member 633 and the flange member 670.

[0456] As in Example 5, in the Z direction, when the abutment portion 633e and the hemispherical shape 101c are in contact with each other, the center 101h of the hemispherical shape 101c of the main body drive shaft 101 is within the range of the driving force receiving surface 673a. The centering member 633 is attached to the flange member 670 so as to satisfy this condition (see FIG. 58).

[0457] 58, the flange member 670 has a press-fitted portion 672a at a position corresponding to the press-fitted portion 633b. The press-fitted portion 672a is disposed inward (on the Z2 direction side) of the photosensitive drum unit 30 relative to the press-fitted portion 672d in the Z direction. This makes it possible to suppress the effect of deformation due to the press-fitting of the press-fitted portion 672d on the press-fitted portion 672a. This makes it possible to align the center of the inverted cone shape 33a and the center of the photosensitive drum 1 with high precision.

[0458] [Coupling member engagement process with main body drive shaft] Next, the process of engagement between the coupling member 628 and the main body drive shaft 101 will be described in detail.

[0459] As in Example 1, as shown in Figure 64(a), the coupling member 628 is inserted into the main body drive shaft 101 in a state inclined by approximately 0.5 to 2 degrees relative to the state in which the cartridge 7 is positioned relative to the image forming apparatus main body 100A (shown in Figure 64(e)).

[0460] As shown in FIG. 64(b), first, the tip of the inner peripheral surface 671b of the cylindrical portion 671 of the flange member 670 abuts against the rough guide portion 101g of the main body drive shaft 101. The main body drive shaft 101 is configured to be cantilevered at the bearing portion 101d. Therefore, as in Example 5, the coupling 7 is inserted into the main body drive shaft 101 with the rough guide portion 101g of the main body drive shaft 101 aligned with the inner peripheral surface 671b of the coupling member 670. As in Example 1, the engagement portion 673 is positioned such that the length L2 of the driving force receiving surface 673 satisfies the relationship L1 > L2, where L1 is the distance from the front end face of the cylindrical portion 671 to the front end face of the engagement portion 673 in the Z direction (see FIG. 58). Therefore, as in Example 5, the ball-returning shape 101c at the tip of the main body drive shaft 101 can be prevented from hitting an unexpected location on the engagement portion 673 or the base portion 674. This allows the engagement portion 673 and the base portion 674 to be protected.

[0461] 64(b), when the coupling member 628 is further inserted toward the rear side of the main body drive shaft 101, the insertion tapered surface 573d of the engagement portion 673 comes into contact with the hemispherical shape 101c at the tip of the main body drive shaft 101, as in Example 5 (shown in FIG. 64(c)). The inclined surface of the insertion tapered surface 573d and the spherical shape of the hemispherical shape 101c guide the main body drive shaft 101 to approximately the center of the three engagement portions 673.

[0462] As in the fifth embodiment, when the coupling member 628 is further inserted into the main body drive shaft 101, the base 674 elastically deforms radially outward so that the engaging portion 673 conforms to the hemispherical shape 101c. As a result, as shown in FIG. 65(a), the engaging portion 673 moves (retracts) to the outer diameter of the shaft portion 101f of the main body drive shaft 101. This movement causes the coupling member 628 to be attached to the main body drive shaft 101 until the removal taper surface 673e of the engaging portion 673 is located further back in the Z direction than the main body-side removal taper 101i of the main body drive shaft 101, as shown in FIG. 64(d).

[0463] Thereafter, similarly to the first embodiment, the cartridge 7 is lifted up so that the drum unit bearing member 39L of the cartridge 7 abuts against the front cartridge positioning portion 110. By lifting the cartridge 7, the cartridge 7 is positioned relative to the image forming apparatus main body 100A (shown in FIG. 21(d)). This movement of the cartridge 7 eliminates the inclination of the coupling member 628, as shown in FIG. 64(e).

[0464] When the main body drive shaft 101 rotates, the main body drive transmission groove 101a and the engaging portion 673 are in phase, as in Example 5. This at least partially releases the elastic deformation of the base portion 674, and a portion of the tip side of the engaging portion 673 enters the main body drive transmission groove 101a. This causes the coupling member 628 and the main body drive shaft 101 to engage (shown in Figure 65(b)).

[0465] If the main body drive transmission groove 101a and the engagement portion 673 are in phase, the elastic deformation of the base portion 674 is at least partially released at the stage of FIG. 64(d), resulting in the state of FIG. 65(b).

[0466] [Coupling member driven by main body drive shaft] Similar to the first embodiment, driving force receiving surface 673a has a twisted shape and is tilted with respect to the rotation axis of flange member 670. This is to ensure that when driving force receiving surface 673a receives driving force from main body drive shaft 101, a force is generated that ensures that inverted cone shape 633a of alignment member 633 abuts reliably against hemispherical shape 101c at the tip of main body drive shaft 101. The twisting direction is such that the outer side (Z1 direction side) of photosensitive drum unit 30 of driving force receiving surface 673a is located upstream in the rotation direction of photosensitive drum 1 relative to the inner side (Z2 direction side) (shown in Figure 66).

[0467] As in the fifth embodiment, when flange member 670 is viewed along the Z direction, a straight line is drawn from inner diameter end 673b of driving force receiving surface 673a in a direction perpendicular to driving force receiving surface 673a. Root portion 674a is located upstream of this line in the rotation direction of flange member 670 (see FIG. 67). As a result, when driving force F1 is applied from main body drive shaft 101, winding portion 574b winds around shaft portion 101f. As in the fifth embodiment, even if the load applied to photosensitive drum unit 30 changes, the amount of deformation of base portion 574 is small, and therefore the effect of deformation on the rotation of photosensitive drum unit 30 can be minimized.

[0468] In addition, in this embodiment, the root portion 674a of the base portion 674 is disposed at the same position as the press-fit portion 672d in the Z direction (see FIG. 59). That is, the root portion 674a is disposed inside the photosensitive drum 1 in the Z direction. That is, when the photosensitive drum (cylinder) 1 and the base portion 674 are projected onto the axis of the photosensitive drum 1, the projected area of ​​the root portion 674a overlaps with the projected area of ​​the photosensitive drum 1 on the axis. Particularly in this embodiment, the entire projected area of ​​the base portion 674 overlaps with the projected area of ​​the photosensitive drum 1. That is, the entire projected area of ​​the base portion 674 is inside the projected area of ​​the photosensitive drum 1.

[0469] Similarly, in the Z direction, the engagement portion 673 is disposed inside the photosensitive drum 1. In other words, when the photosensitive drum 1 and the engagement portion 673 are projected onto the axis of the photosensitive drum 1, the projected area of ​​the engagement portion 673 overlaps with the projected area of ​​the photosensitive drum 1 on the axis.

[0470] In Example 5, root portion 574a is disposed outward in the Z direction from mounting portion 572 (see FIG. 59). However, in this configuration, when driving force F1 is received by main body drive shaft 101 on driving force receiving surface 573a, there is a concern that torsional deformation may occur in cylindrical portion 571 between root portion 574a and press-fit portion 572d.

[0471] In contrast, when at least a portion of base portion 674a is disposed at the same position as press-fit portion 672d in the Z direction as in this embodiment, the aforementioned torsional deformation is reduced. This is because press-fit portion 672d is covered at its outer periphery by photosensitive drum 1, and therefore press-fit portion 672d is less likely to deform even when subjected to an external force via base portion 674a. In other words, even if driving force receiving surface 573a receives a driving force from the device main body, as long as base portion 674a is attached to press-fit portion 672, press-fit portion 672 is less likely to deform torsionally, and cylindrical portion 671 is also less likely to deform torsionally. In other words, the amount of deformation of flange member 670 can be kept small.

[0472] As a result, even if the load applied to the photosensitive drum unit 30 changes, the amount of deformation of the flange member 670 is small, so it is possible to minimize the effect of the deformation on the rotation of the photosensitive drum unit 30. As a result, the photosensitive drum 1 can be driven more stably.

[0473] Furthermore, the engaging portion 673 (driving force receiving surface 673a) is disposed on the inner side of the photosensitive drum 1 in the Z direction. This arrangement provides the following effects.

[0474] When the positions of the main body drive shaft 101 and the coupling member 628 are misaligned due to component tolerances, arranging the driving force receiving surface 673a farther from the bearing portion 101d of the main body drive shaft 101 can minimize the inclination of the main body drive shaft 101. Arranging the driving force receiving surface 673a inside the press-fit portion 672d, as shown in this embodiment, rather than arranging the driving force receiving surface 673a inside the cylindrical portion allows the driving force receiving surface 673a to be positioned inside the photosensitive drum 1 in the Z direction. This approach minimizes the inclination of the main body drive shaft 101 even when the positions of the main body drive shaft 101 and the coupling member 628 are misaligned. As a result, the photosensitive drum 1 can be driven stably.

[0475] [Removing the coupling member from the drive shaft] The operation of removing the coupling member will be described with reference to Figure 69. As in Example 5, when the rotational drive of the main body drive shaft 101 stops, the drive force receiving surface 673a and the main body drive transmission surface 101b are in contact with each other. In this state, part of the engaging portion 673 is inserted into the main body drive transmission groove 101a (shown in Figure 68(a)).

[0476] When the cartridge door 104 is opened, the front cartridge lower guide 109 descends, and the drum unit bearing member 39L moves away from the front cartridge positioning portion 110 of the image forming apparatus main body 100A. At this time, the coupling member 628 and the main body drive shaft 101 are inclined at an angle of approximately 0.5 to 2 degrees with respect to the installation completion state (Z direction) as in the fifth embodiment (shown in Figure 68(b)).

[0477] When removal of the cartridge 7 from the image forming apparatus main body 100A begins, the removal tapered surface 673e of the engaging portion 673 abuts against the main body-side removal taper 101i, as in Example 5. When the removal tapered surface 673e abuts against the main body-side removal taper 101i, the base 674 begins to elastically deform, and the engaging portion 673 moves radially outward along the main body-side removal taper 101i (shown in Figure 68(c)).

[0478] When the coupling member 628 is further removed from the main body drive shaft 101, the state becomes similar to that shown in Figure 65(a), as in Example 5, and the base portion 674 further elastically deforms, moving the engaging portion 673 to the outer diameter of the shaft portion 101f of the main body drive shaft 101. When the engaging portion 673 moves to the outer diameter of the shaft portion 101f, the engagement between the engaging portion 673 and the main body drive transmission groove 101a is released (disengaged). At this time, as shown in Figure 68(d), the coupling member 628 can be removed from the main body drive shaft 101.

[0479] Furthermore, when the coupling member 628 is removed from the main body drive shaft 101, the elastic deformation of the base portion 674 is released, and the position of the engaging portion 673 also returns to the position before the elastic deformation, as shown in FIG. 68(e).

[0480] By the above operation, the coupling member 628 can be removed from the main body drive shaft 101.

[0481] [Insert molding of flange parts] As long as the coupling member 628 can be mounted easily and drive transmission can be stabilized, the material, shape, and manufacturing method can be appropriately selected. In particular, when considering mass production, it is preferable to use a resin material.

[0482] Specifically, by molding the coupling member 628 using the resin materials exemplified below (POM, PPS, PS, nylon, etc.), satisfactory results were obtained in terms of drive transmission and ease of attachment to the device main body.

[0483] Under these circumstances, the results of a study into further improving the performance of coupling members are described below.

[0484] Under high temperature conditions, it is conceivable that the engagement portion 673 of the flange member 670 and the main body drive transmission groove 101a of the main body drive shaft 101 may be left out of phase with each other, i.e., the base portion 674 may be left in an elastically deformed state. If this condition continues, creep deformation may occur in the base portion 674. The amount of creep deformation depends on the stress applied to the base portion and the environmental temperature, and therefore varies depending on the straight thickness 674l of the base portion and the resin material. The results of extensive research into further improving reliability under such special conditions are described below.

[0485] FIG. 69 is a diagram illustrating a situation that occurs when creep deformation of the base portion 3674 is large. Specifically, this diagram illustrates a situation in which the inner diameter end 3673b of the driving force receiving surface 3673a is deformed radially outward to a position corresponding to the relief portion 101j. For example, if a resin material with large creep deformation is used, the creep deformation of the base portion 3674 progresses, and even if the main body drive shaft 101 rotates, the engaging portion 3673 may not be retracted radially inward. In other words, there is a concern that a situation may arise in which the photosensitive drum 1 cannot be stably rotated or driven.

[0486] Therefore, in order to suppress creep deformation, a metal plate (metal plate, plate-shaped metal) was inserted inside the resin material as an auxiliary member. This made it possible to suppress creep deformation more effectively than a structure made only of resin. Furthermore, it was found that if a resin material with excellent creep resistance, such as POM or PPS, is used, sufficient reliability can be ensured even without inserting an auxiliary member inside the resin. Condition 1: POM (LC750 manufactured by Asahi Kasei Chemicals): 0.2mm thick stainless steel sheet metal inside Condition 2: PPS (Toray Torelina A900) Condition 3: POM (LC750 manufactured by Asahi Kasei Chemicals) Condition 4: PS (PS Japan VS142): 0.2mm thick stainless steel sheet metal inside Condition 5: PS (PS Japan VS142)

[0487] When the engaging portion 673 of the flange member 670 and the main body drive transmission groove 101a of the main body drive transmission shaft 101 were stored in a high-temperature environment (50°C for 3 days) with the phases of the engaging portion 673 and the main body drive transmission shaft 101 misaligned, no significant creep deformation occurred under conditions 1 to 4. Specifically, no creep deformation occurred, which would have a significant impact on drive transmission performance. However, when a resin material with low creep resistance, such as PS, was used, creep deformation did affect drive transmission performance (condition 5). However, even with a material with a low deflection temperature under load, such as PS, creep deformation can be suppressed by reinforcing it with a stainless steel sheet metal reinforcing member (auxiliary member) (condition 4).

[0488] In other words, even if the base 674 is made of only a resin material, if the material has excellent creep resistance, it will have sufficient resistance to creep deformation without inserting a reinforcing member. Naturally, inserting an auxiliary member is preferable to ensure high reliability even in higher temperature environments for longer periods of time. In other words, a configuration in which a resin material with excellent creep resistance, such as POM, is reinforced with stainless steel sheet metal, as in condition 1, is preferable when creep deformation is taken into consideration. This prevents the engagement of the drive force receiving surface 673a with the main body drive transmission surface 101b from becoming shallow, allowing for more reliable engagement with the main body drive shaft 101.

[0489] The structure in which the sheet metal member 635 is insert-molded into the flange member 670 will be described in detail below.

[0490] In this embodiment, three sheet metal members 635 (stainless steel sheet metal) serving as reinforcing members are arranged at equal intervals in the circumferential direction of the flange member. The sheet metal members 635 are members made by processing a metal plate (metal plate), and are stainless steel plates, i.e., plates made of an alloy mainly composed of iron. The sheet metal members 635 are not necessarily limited to being made of stainless steel or iron, and other materials may also be used.

[0491] As shown in FIG. 70, the sheet metal member 635 has a base interior 635a, an engagement interior 635c, a flange interior 635b, and a connecting portion 635d.

[0492] The flange interior 635b is sandwiched between a cylinder-side mold 660 and an attachment-side mold 661 by a mold split 662. This is to stably assemble the sheet metal member 635 to the flange member 670 in the Z direction of the flange member 670. In addition, the portion sandwiched between the molds (pressed portion 635h) is configured to be exposed from the resin. In other words, the sheet metal member 635 has an exposed portion that is exposed from the resin portion.

[0493] As shown in FIG. 71, one of the pressed portions 635h is positioned at a position that is 90° out of phase with the crimping groove 672e. Therefore, the crimping groove 672e and the pressed portion 635h can be positioned so that they do not overlap in the circumferential direction. As shown in FIG. 29, the flange portion inner portion 635b is positioned perpendicular to the base portion inner portion 635a that is positioned within the base portion 674. The flange member 670 has three notches 675a ​​in the flange portion 675. The pressed portion 635h is positioned within the range in which the notches are provided. The notches 675a ​​are evenly positioned in the circumferential direction, and one of the notches 675a ​​is positioned perpendicular to the crimping groove 72e.

[0494] The base inner portion 635a is composed of a straight portion inner portion 635e disposed inside the straight portion 674c of the base portion 674, and a winding portion inner portion 635f disposed inside the winding portion 674b (shown in FIG. 72).

[0495] The inside 635f of the winding portion does not have to be rounded to match the winding portion 674b, and may be straight as shown in FIG.

[0496] 72, a connecting hole (through hole) 635g provided in the base interior 635a connects the resin on the front and back of the metal plate, thereby increasing the bonding strength between the resin and the metal. In other words, the communicating hole 63g is a hole into which the resin is placed.

[0497] In order to prevent the base interior 635a from being deformed by the resin pressure during injection molding, the base interior 635a is held between the cylindrical portion side mold 660 and the attachment portion side 661, and therefore the base interior 635a is configured to be exposed from a part of the base 674. This improves the molding accuracy of the base 674.

[0498] 72 and 73, straight portion notch 674g and winding portion notch 674h are provided in the resin molded portions of straight portion interior 635e and winding portion interior 635f, respectively. Base portion interior 635a has straight portion exposed portion 635i and winding portion exposed portion 635j that are exposed to the outside of the resin portion.

[0499] The straight portion exposed portion 635i and the wound portion exposed portion 635j are sandwiched between the cylindrical portion side mold 660 and the attachment portion side mold 661. This makes it possible to prevent the base inside 635a from being deformed by the resin pressure during injection molding.

[0500] As shown in FIGS. 74 and 75, the straight portion notch 674g and the winding portion notch 674h have a straight portion notch tapered surface 674i and a winding portion notch tapered surface 674j, respectively. The cylindrical portion side mold 660 and the attachment portion side mold 661 have tapered shapes corresponding to the shapes of the straight portion notch tapered surface 674i and the winding portion notch tapered surface 674j, respectively. Therefore, even if the sheet metal member 635 is slightly misaligned with the corresponding groove shape of the mold due to dimensional tolerances, the tapered shapes of the cylindrical portion side mold 660 and the attachment portion side mold 661 can guide the sheet metal member 635 to the predetermined position of the mold (the corresponding groove shape of the mold). As a result, when the resin portion is molded, the engagement portion interior 635a is positioned inside the engagement portion 673.

[0501] As shown in FIG. 73, the connecting portion 635d has a shape for connecting the base portion interior 635a and the flange portion interior 635b.

[0502] The above is a description of the configuration for insert-molding the metal plate 635 into the flange member 670.

[0503] In each of the above and below-described embodiments, insert molding may be carried out in order to obtain good creep properties, as in this embodiment.

[0504] Example 7 The seventh embodiment will be described with reference to FIG.

[0505] This embodiment is characterized in that a part of the driving force receiving portion and a part of the support portion (engagement portion 673 and base portion 674) that supports the driving force receiving portion are disposed inside the photosensitive drum 1.

[0506] Elements corresponding to those in the above-described embodiments (especially embodiment 6) are given the same names, and explanations of the same points as the above-described elements may be omitted. The following explanation will focus on the points that are different from the above-described elements.

[0507] In the sixth embodiment, the root portion 674a of the base portion 674 is disposed at the same position as the press-fit portion 672d in the Z direction (see FIG. 59).

[0508] In contrast, in the embodiment, a portion of the root portion 774a overlaps with the press-fit portion 772d in the Z direction. In other words, when the base portion 674 and the photosensitive drum 1 are projected onto the axis of the photosensitive drum 1, a portion of the projected area of ​​the root portion 774a overlaps a portion of the projected area of ​​the photosensitive drum 1. On the other hand, a portion of the projected area of ​​the root portion 774a is located outside the projected area of ​​the photosensitive drum 1.

[0509] Even with this configuration, it is possible to suppress torsional deformation of the cylindrical portion 771 when the driving force F1 is received by the driving force receiving surface (driving force receiving portion) 773a, although not as much as in Example 6, and it is possible to keep the amount of deformation of the flange member 70 small. As a result, even if the load received by the photosensitive drum unit 30 changes, it is possible to keep the effect of deformation on the rotation of the photosensitive drum unit 30 small. As a result, it is possible to drive the photosensitive drum 1 stably.

[0510] Example 8 The eighth embodiment will be described with reference to FIGS. 77A, 77B, 88 and 79.

[0511] This embodiment is characterized in that the support portion (engagement portion 873 and base portion 874) that supports the driving force receiving portion 873a extends in the circumferential direction of the coupling member, while the support portion also extends in the axial direction of the coupling member.

[0512] Elements corresponding to those in the above-described embodiments (especially embodiment 5) are given the same names, and explanations of the same points as the above-described elements may be omitted. The following explanation will focus on the points that are different from the above-described elements.

[0513] In Example 5, the driving force receiving surface 573a and the root portion 574a of the base portion 574 are configured to be disposed on the inner circumferential surface 571b of the cylindrical portion 571 in the Z direction (see FIG. 39). Also, as shown in FIG. 45, the root portion 574a of the base portion 574 is disposed so as to overlap the entire driving force receiving surface 573a in the Z direction. That is, the straight line connecting the rear end (root portion 574a) and the front end (driving force receiving surface 573a) of the base portion 574 is substantially perpendicular to the axis (Z direction) of the flange member. That is, the base portion 574 is tilted at approximately 90° with respect to the Z direction (axis).

[0514] In contrast, in this embodiment, the extending direction of the base portion 874 is inclined with respect to the direction perpendicular to the Z direction. In other words, the base portion 874 extends at least in the circumferential direction of the coupling member, but the extending direction is not parallel to the circumferential direction. While the base portion 874 extends in the circumferential direction of the coupling member, it also extends in the axial direction of the coupling member. As a result, the base portion 874 is inclined with respect to the circumferential direction of the coupling member.

[0515] In addition, in the Z direction, the root portion 874a of the base portion 874 is arranged so as to partially overlap with the winding portion 874b.

[0516] In the Z direction, the driving force receiving surface 873a and the base portion 874a are disposed inside the cylindrical portion 871, as in the fifth embodiment.

[0517] As in Example 5, when the driving force F1 is received by the driving force receiving surface 873a, the winding portion 874b winds around the shaft portion 101f of the main body driving shaft 101, the winding portion 874b rotates integrally with the shaft portion 101f, and the rotational force Fc generated by the driving force F1 is received by the straight portion 874c.

[0518] Unlike this embodiment, Figure 78 shows a case where the root portion 3874a of the base portion 3874 does not overlap the wrapping portion 3874b at all. When the straight portion 3874c receives the rotational force Fc, the root portion 3874a receives a reaction force -Fc of Fc. The inclined straight portion 3874c is pulled by the rotational force Fc and the reaction force -Fc, deforming the straight portion 3874c in a direction that makes the inclination of the straight portion 3874c gentler in a direction perpendicular to the Z direction. After the inclination of the straight portion 3874c becomes gentler, the rotational force Fc is transmitted to the photosensitive drum 1 via the cylindrical portion 3871 and the mounting portion 872.

[0519] As a result, when the load on the photosensitive drum unit 30 changes and the rotational force Fc changes, the deformation amount of the base 3874 changes, so the effect on the rotation of the photosensitive drum unit 30 is greater than in this embodiment.

[0520] In contrast, in the configuration of this embodiment, the root portion 874a has a portion that overlaps with the wrapping portion 874b in the Z direction. In other words, when the wrapping portion 874b and the root portion 874a are projected onto the axis of the drum unit 30, at least a portion of the projected area of ​​the wrapping portion 874b and at least a portion of the projected area of ​​the root portion 874b overlap.

[0521] 79, even if a rotational force Fc is applied, the rotational force Fc can be received by the overlapping base portion 874a. Therefore, the rotational force Fc can be transmitted to the cylindrical portion 871 without substantially deforming the straight portion 874c in a direction that makes the slope of the straight portion 874c gentler in a direction perpendicular to the Z direction. As a result, even if the load applied to the photosensitive drum unit 30 changes, the effect on the rotation of the photosensitive drum unit 30 can be reduced.

[0522] In order to wrap the base 874 around the main body drive shaft 101 as in this embodiment, it is desirable that the base 874 be tilted within a range of 30° to 90° (30° or more and 90° or less) with respect to the Z-axis direction (axis Ax of the coupling member). A more preferable range is 50° to 90° (50° or more and 90° or less).

[0523] The inclination of the base portion 874 (support portion of the driving force receiving portion) with respect to the axis Ax of the coupling member is defined as follows.

[0524] Let us look at a cross section of the coupling member cut so that the fixed end (root portion 874a) of the base portion 874 and the axis Ax of the coupling member pass through (see Figure 79). In this cross section, we will look at the angle between the base portion 874 and the axis Ax. In Figure 79, the angle we are looking for is the angle formed by a line extending along the left side surface of the base portion 874 from the fixed end (root portion 874a) of the base portion 874 to the free end (engagement portion 873), and a line extending from the fixed end (874a) parallel to the axis Ax. When measured in Figure 79, this angle is approximately 36°.

[0525] In this embodiment, the base portion 874 is inclined so that its free end is positioned further outward in the axial direction (on the arrow Z1 side) than its fixed end.

[0526] However, the base 874 may be inclined so that its free end is positioned more inward in the axial direction (toward the arrow Z2) than its fixed end. In this case, the inclination of the base 874 (support portion of the driving force receiving portion) with respect to the axis Ax may be defined as follows: The desired angle is the angle formed by a line extending from the fixed end of the base 874 to the free end along the right side surface of the base 874 and a line extending from the fixed end parallel to the axis Ax.

[0527] That is, the angle is measured so that the base 874 is always at or below 90° with respect to the axis Ax.

[0528] Example 9 The ninth embodiment will be described with reference to FIGS.

[0529] In this embodiment, the fixed end (root portion 974a) of the base portion 974 is positioned inside the photosensitive drum 1, while at least a portion of the driving force receiving surface 673a and the engagement portion 673 is positioned outside the photosensitive drum 1.

[0530] Elements corresponding to those in the above-described embodiments (especially embodiment 6) are given the same names, and explanations of the same points as the above-described elements may be omitted. The following explanation will focus on the points that are different from the above-described elements.

[0531] In Example 6, the driving force receiving surface 673a and the root portion 674a of the base portion 674 are configured to be disposed on the inner circumferential surface 672h of the mounting portion 672 in the Z direction (see FIG. 59). In addition, the root portion 674a of the base portion 674 is disposed so as to overlap the entire driving force receiving surface 673a in the Z direction. In other words, the entire driving force receiving surface 673a and the entire support portion that supports the driving force receiving surface 673a are disposed inside the photosensitive drum 1.

[0532] 80, in this embodiment, the base 974 is inclined relative to a direction perpendicular to the Z direction, and a root portion 974a of the base 974 is disposed so as to partially overlap with the winding portion 974b in the Z direction. In the Z direction, the root portion 974a is disposed on the inner circumferential surface 972h of the attachment portion 972, as in the sixth embodiment.

[0533] The effect of arranging the root portion 974a so that it partially overlaps with the wrapping portion 974b in the Z direction is the same as in Example 8. Furthermore, the effect of arranging the root portion 974a on the inner circumferential surface 972h of the attachment portion 972 in the Z direction is the same as the effect of Example 6 over Example 5, and the same effect can be obtained in this example over Example 8.

[0534] As shown in FIG. 81, even if the driving force receiving surface (driving force receiving portion) 973a is disposed on the inner circumferential surface 972h of the attachment portion 972 in the Z direction, the same effect can be obtained.

[0535] Also, as shown in Figure 82, even in a configuration in which a portion of the root portion 974a is in contact with the inner surface 972h of the mounting portion 972 in the Z direction, the present embodiment can achieve the same effect as compared to Example 8, as compared to Example 5, as in Example 7.

[0536] Example 10 The tenth embodiment will be described with reference to Figures 83 to 86. Elements corresponding to those in the previous embodiments (especially the sixth embodiment) will be given the same names, and explanations of similarities with the previous elements may be omitted. The following description will focus on differences from the previous elements.

[0537] In the sixth embodiment, as shown in FIG. 60, the engagement portions 673 and base portions 674 are arranged at three locations on the flange member 670, evenly spaced in the circumferential direction.

[0538] 83, in this embodiment, there is one engaging portion 1073 and one base portion 1074. A driving force receiving surface (driving force receiving portion) 1073a is provided on the engaging portion 1073. The engaging portion 1073 and the base portion 1074 are supporting portions that support the driving force receiving portion.

[0539] Furthermore, a force receiving portion 1077 is provided to prevent the main body drive shaft 101 from falling too far due to the force of elastic deformation of the base portion 1074 when the coupling member 1028 is attached to the main body drive shaft 101 .

[0540] More specifically, in the process of the coupling member 1028 engaging with the main assembly drive shaft 101, the base 1074 elastically deforms, and the engaging portion 1073 moves radially outward. At that time, the shaft portion 101f of the main assembly drive shaft 101 is pushed to the opposite side by the force of the elastic deformation of the base 1074. At this time, as shown in FIG. 84, the force receiving portion 1077 abuts against the shaft portion 101f, preventing the main assembly drive shaft 101 from falling too far. As a result, the force receiving portion 1077 maintains good mountability of the cartridge 7 to the image forming apparatus main assembly 100A.

[0541] Before the base 1074 is elastically deformed, at least a part of the insertion tapered surface 1073d and at least a part of the flange member 1070 face each other with the axis of the flange member 1077 therebetween (see FIG. 83). Similarly, when the base 1074 is elastically deformed, at least a part of the driving force receiving surface and at least a part of the force receiving portion 1077 face each other with the axis therebetween (shown in FIG. 84).

[0542] 85, the alignment of the coupling member 1028 and the main body drive shaft 101 is performed by an alignment member 1033 having an inverted cone shape 1033a, as in Example 6. At this time, the radius R3 of the force receiving portion 1077 is larger than the radius R2 of the shaft portion 101f, and the force receiving portion 1077 does not come into contact with the shaft portion 101f.

[0543] As shown in FIG. 84, the position of the force receiving portion 1077 in the Z direction is the same as that of the engaging portion 1073 in the Z direction.

[0544] In this embodiment, the engaging portion 1073 and the root portion 1074a of the base portion 1074 are disposed inside the mounting portion 1072 in the Z direction, as in the sixth embodiment. However, as in the fifth embodiment, they may be disposed on the cylindrical portion 1071 (FIG. 86(a)), and as in the seventh embodiment, a configuration may be adopted in which a portion of the root portion 1074a overlaps the press-fit portion 1072d (FIG. 86(b)). Also, as in the eighth and ninth embodiments, the base may be inclined with respect to a direction perpendicular to the Z direction, and the root portion 1074a of the base portion 1074 may partially overlap the wrapping portion 1074b in the Z direction (shown in FIGS. 86(c), d, e, and f)).

[0545] Example 11 The eleventh embodiment will be described with reference to FIGS. 87A, 87B, 88 and 89.

[0546] Elements corresponding to those in the above-described embodiments (especially embodiment 6) are given the same names, and explanations of the same points as the above-described elements may be omitted. The following explanation will focus on the points that are different from the above-described elements.

[0547] In the sixth embodiment, as shown in FIG. 60, the engagement portion 673 and the base portion 674 are arranged at three locations evenly spaced around the circumference of the flange member 670, and as shown in FIG. 58, the coupling member 628 is composed of the flange member 670 and the centering member 633.

[0548] In contrast, in this embodiment, as shown in Figures 87A and 87B, an engagement portion 1173 and a base portion 1174 are provided in one location on coupling member 1128. A driving force receiving portion is provided on engagement portion 1173. Engagement portion 1173 and base portion 1174 are support portions that movably support the driving force receiving portion.

[0549] 87A, 87B, 88, and 89, the coupling member 1128 is provided with a radial positioning portion 1076a having approximately the same diameter as the shaft portion 101f of the main body drive shaft 101 in a location in the circumferential direction other than the engaging portion 1173 and the base portion 1174. Also, abutment portion 1076b is provided against which hemispherical shape 101c, which is the hemispherical shape at the tip of the main body drive shaft 101, abuts when the drive of the main body drive shaft 101 is transmitted to the coupling member 228.

[0550] As a result, what was configured with two parts, the flange member 670 and the centering member 633 in the sixth embodiment, is configured with one part.

[0551] As shown in FIG. 87A, the radial positioning portions 1176a are arranged at three locations in the circumferential direction. The angle between the outer end of the radial positioning portion 1176a and the axial center of the flange is greater than 180°, and they are arranged at locations other than 120° and 240° from the engaging portion 1173. As described in the first embodiment, the shaft portion 101f of the main body drive shaft 101 has three main body drive transmission grooves 101a evenly spaced in the circumferential direction (at 120° intervals, approximately equal intervals). As in the first embodiment, after one of the main body drive transmission grooves 101a of the main body drive shaft 101 is aligned with the engaging portion 1173, the driving force receiving surface 1173a of the main body drive transmission surface 101b comes into contact, transmitting the drive force from the main body drive shaft 101 to the coupling member 1128.

[0552] At this time, the radial positioning portion 1076a is disposed at a position different from the three main body drive transmission grooves 101a evenly spaced on the shaft portion 101f of the main body drive shaft 101. The radial positioning portion 1076a does not enter the drive transmission grooves 101a. Therefore, the radial positioning portion 1176a is positioned radially on the shaft portion 101f without being affected by the two main body drive transmission grooves 101a that are not engaged with the driving force receiving surface 1173.

[0553] As shown in FIG. 88, the radial positioning portion 1176a is disposed at the same position as the driving force receiving surface 1173a in the Z direction.

[0554] As a result, while in the sixth embodiment the flange member 670 and the alignment member 633 are configured as two parts, in this embodiment it is possible to configure the flange member 670 and the alignment member 633 as one part.

[0555] 87A, the abutment portion 1176b has a shape that does not overlap with the projection plane of the engaging portion 1173, the base portion 1174, and the radial positioning portion 1176a and its periphery by about 1 mm when viewed from the Z direction. This allows the coupling member 1128 to be injection molded using a two-body mold consisting of a cylinder-side mold and an attachment-side mold, similar to the flange member 670 of Example 6.

[0556] In this embodiment, the engaging portion 1173 and the root portion 1174a of the base portion 1174 are disposed inside the mounting portion 1172 in the Z direction, as in the sixth embodiment. However, as in the fifth embodiment, they may be disposed on the cylindrical portion 1171 (shown in FIG. 90(a)). Also, as in the seventh embodiment, a configuration may be adopted in which a portion of the root portion 1174a overlaps with the press-fit portion 1172d (shown in FIG. 90(b)). Also, as in the eighth and ninth embodiments, a configuration may be adopted in which the base is inclined with respect to a direction perpendicular to the Z direction, and the root portion 1174a of the base portion 1174 partially overlaps with the wound portion 1174b in the Z direction (shown in FIGS. 90(c), d, e, and f)).

[0557] Example 12 The twelfth embodiment will be described with reference to Figures 91 to 93. Elements corresponding to those in the previous embodiments (especially the sixth embodiment) will be given the same names, and explanations of similarities with the previous elements may be omitted. The following description will focus on differences from the previous elements.

[0558] In Example 6, as shown in Fig. 60, the engagement portions 673 and base portions 674 were arranged at three locations evenly spaced in the circumferential direction of the flange member 670. On the other hand, in this example, as shown in Fig. 91, the engagement portions 1273 and base portions 1274 are arranged at two locations (120° apart). The engagement portion 1273 is provided with a driving force receiving portion 1273a. The engagement portion 1273 and base portion 1274 are also support portions that movably support the driving force receiving portion 1273a.

[0559] Furthermore, a force receiving portion 1277 is provided to prevent the main body drive shaft 101 from falling too far due to the force of elastic deformation of the base portion 1274 when the coupling member 1128 is attached to the main body drive shaft 101.

[0560] More specifically, when the coupling member 1228 is engaged with the main assembly drive shaft 101, the base 1274 of the force receiving portion 1277 elastically deforms, causing the engaging portion 1273 to move radially outward. At this time, the shaft portion 101f of the main assembly drive shaft 101 is pushed circumferentially in the opposite direction from the engaging portion by the force of the elastic deformation of the base. At this time, the force receiving portion 1277 abuts against the shaft portion 101f, preventing the main assembly drive shaft 101 from tilting too much. As a result, the cartridge 7 can be easily installed in the image forming apparatus main assembly 100A.

[0561] In the circumferential direction, they are arranged at a position including the midpoint of a line connecting the inner diameter ends of the insertion tapered surfaces 1273d of the base 1274 before elastic deformation and an extension of a line connecting the axis of the flange member 1270 (shown in FIG. 91). In this embodiment, the engaging portions 1273 are arranged at intervals of 120°, so they should be arranged so as to include a range of 120° from the inner diameter end of the insertion tapered surface 1273d.

[0562] 92, the alignment of the coupling member 1228 and the main body drive shaft 101 is performed by an alignment member 1233 having an inverted cone shape 1233a, as in the sixth embodiment. At this time, the radius R3 of the force receiving portion 1277 is larger than the radius R2 of the shaft portion 101f, and the force receiving portion 1277 does not come into contact with the shaft portion 101f.

[0563] As shown in FIG. 92, the position of the force receiving portion 1277 in the Z direction is the same as that of the engaging portion 1273 in the Z direction.

[0564] In this embodiment, the engaging portion 1273 and the root portion 1274a of the base portion 1274 are disposed inside the mounting portion 1272 in the Z direction, as in the case of the sixth embodiment. However, as in the case of the fifth embodiment, they may be disposed on the cylindrical portion 1271 (FIG. 93(a)), and as in the case of the seventh embodiment, a configuration may be adopted in which a portion of the root portion 1274a overlaps with the press-fit portion 1272d (FIG. 93(b)). Also, as in the cases of the eighth and ninth embodiments, a configuration may be adopted in which the base is inclined with respect to a direction perpendicular to the Z direction, and the root portion 1274a of the base portion 1274 partially overlaps with the winding portion 1274b in the Z direction (shown in FIGS. 93(c), d, e, and f)).

[0565] Example 13 The thirteenth embodiment will be described with reference to FIGS.

[0566] Elements corresponding to those in the above-described embodiments (especially embodiment 6) are given the same names, and explanations of the same points as the above-described elements may be omitted. The following explanation will focus on the points that are different from the above-described elements.

[0567] 60, in Example 6, the engagement portions 673 and base portions 674 are arranged at three locations evenly spaced in the circumferential direction of the flange member 670. Similarly, the main body drive shaft 101 has three main body drive transmission grooves 101a arranged at three locations evenly spaced in the circumferential direction of the shaft portion 101f of the main body drive shaft 101.

[0568] In this embodiment, as shown in Figures 94 and 95, the engagement portion 1373 and the base portion 1374 are disposed at two locations evenly spaced in the circumferential direction of the flange member 1370. The engagement portion 1373 is provided with a driving force receiving portion 1373a. The engagement portion and the base portion are support portions that movably support the driving force receiving portion. The engagement portion is a protrusion, and the base portion is an extension.

[0569] Similarly, as shown in FIG. 95, the main body drive shaft 13101 also has two main body drive transmission grooves 13101a arranged at equal intervals in the circumferential direction of the shaft portion 13101f of the main body drive shaft 13101.

[0570] The hook portions 1372b are arranged at four locations evenly spaced in the circumferential direction of the flange member, and, in addition, as shown in FIG. 96, the retaining portions 1333c of the alignment member 1333 are also arranged at four locations corresponding to the four locations.

[0571] The engaging portion 1373 and the root portion 1374a of the base portion 1374 are disposed inside the mounting portion 1372 in the Z direction, as in Example 6 (shown in FIG. 97). However, the engaging portion 1373 and the root portion 1374a of the base portion 1374 may be disposed on the cylindrical portion 1371, as in Example 5 (shown in FIG. 98(a)). Also, as in Example 7, a configuration in which a portion of the root portion 1374a overlaps the press-fit portion 1372d may be used (shown in FIG. 98(b)). Also, as in Examples 8 and 9, a configuration in which the base is inclined with respect to a direction perpendicular to the Z direction, and the root portion 1374a of the base portion 1374 partially overlaps with the wrapping portion 1374b in the Z direction may be used (shown in FIGS. 98(c), d, e, and f).

[0572] Example 14 The fourteenth embodiment will be described with reference to FIGS.

[0573] Elements corresponding to those in the above-described embodiments (especially embodiment 6) are given the same names, and explanations of the same points as the above-described elements may be omitted. The following explanation will focus on the points that are different from the above-described elements.

[0574] In the sixth embodiment, a retaining portion 633c having a snap-fit ​​shape is used as a shape for preventing the aligning member 633 from falling off from the flange member 670 (shown in FIG. 63).

[0575] 99, in this embodiment, a recess 1633k and a rotation stopper 1633l are provided as a method for fixing the alignment member 1633 to the flange member 1670.

[0576] The configuration in which the hemispherical shape 101f of the main body drive shaft 101 is aligned with the coupling member 1628 using the inverted cone shape 1633a is the same as in the sixth embodiment.

[0577] The specific configuration will be described below.

[0578] As shown in FIG. 99, the recess 1633k has a groove shape 1633n that is provided on the Z1 direction side of the fitting portion 1633b and that is open on the upstream side in the rotation direction of the coupling member 1628.

[0579] As shown in FIG. 99, the rotation stopper portion 1633l is positioned on the Z2 side of the mating portion 1633b, extends circumferentially around the mating portion 1633b, and has a snap-fit ​​shape with a free end on the upstream side of the rotation direction of the coupling member 1628.

[0580] The snap-fit ​​shaped tip 1633m of the rotation stopper 1633l extends radially inward of the alignment member 1633. As shown in FIG. 100, the rotation stopper 1633l has a root 1633r, which is the starting point of elastic deformation, on the fixed end side of the snap-fit ​​shape, and the tip 1633m has a holding surface 1633q. The root 1633r is perpendicular to the holding surface 1633q and is located downstream in the direction of rotation with respect to a line passing through the tip of the holding surface 1633q. The tip 1633m also has a tapered shape 1633n on the upstream side in the direction of rotation of the coupling member 1628.

[0581] As shown in FIG. 101, the flange member 1670 has a hook portion 1672b at a position corresponding to the recessed portion 1633k in the Z direction, and an engagement portion 1672i at a position corresponding to the rotation stopper portion 1633l.

[0582] 102, the hook portions 1672b are arranged in three locations approximately in the middle of each base portion 1674a in the circumferential direction of the flange member 1670, similar to the hook portions 672b in Example 6. In addition, as shown in FIG. 99, the groove shapes 1633n of the recessed portion 1633k are also arranged in three locations corresponding to the hook portions 1672b.

[0583] 101, the engaging portion 1672i is disposed on the inner side (Z2 direction side) of the guide taper 1672g, and projects from the end face 1672l of the mounting portion 1672 toward the inner side (Z2 side) of the flange member 1670. As shown in FIG.

[0584] As shown in FIGS. 101 and 103, the engaging portion 1672i is disposed radially outward from the inner periphery 1672h and radially inward from the press-fit portion 1672d.

[0585] Furthermore, the engagement surface 1672j on the upstream side in the rotation direction has a shape corresponding to the tip end 1633m of the rotation stopper portion.

[0586] 99, the alignment member 1633 has an abutment surface 1633p that abuts against an end surface 1672l of the mounting portion 1672 of the flange member 1670 in the Z direction. As shown in Fig. 106, the width in the Z direction of the groove shape 1633n of the recess 1633k is wider than the width of the hook portion 1672b. When the end surface 1672l of the flange member 1670 abuts against the abutment surface 1633p, the hook portion 1672b enters within the range of the groove shape 1633n in the Z direction.

[0587] The groove shape 1633n has a play relative to the hook portion 1672b. This play allows the alignment member 1633 to move in the Z direction relative to the flange member 1670. Even if the alignment member 1633 can move in the Z direction by the play, the inverted cone shape 1633a is positioned so that the center 101h of the hemispherical shape 101c of the main body drive shaft 101 overlaps with the driving force receiving surface (driving force receiving portion) 1673a in the Z direction.

[0588] Figure 105 shows a method for assembling the alignment member 1633 to the flange member 1670. First, as shown in Figure 105(a), the alignment member 1633 is assembled to the flange member 1670 from the rear side (Z2 side) to the front side (Z1 side) of the flange member 1670 in a phase downstream in the rotation direction relative to the completed installation state of the alignment member 1633 (Figure 105(c)).

[0589] 105(b), the alignment member 1633 is assembled to the flange member 1670 until the abutment surface 1633n abuts against the end surface 1672l of the flange member 1670. As a result, the groove shape 1633n of the recess 1633k comes to a position corresponding to the hook portion 1672b in the Z direction.

[0590] Next, after assembling the alignment member 1633 to the flange 1670 up to the installation completion position in the Z direction, the alignment member is rotated upstream in the rotation direction of the coupling member 1628. As the alignment member is rotated, the tapered shape 1633i provided on the rotation stopper portion 1633l of the alignment member 1633 comes into contact with the tapered shape 1672k of the flange member 1670, as shown in Figure 105(c).

[0591] As described above, the rotation stopper 1633l has a snap-fit ​​shape, and therefore the rotation stopper 1633l moves over the engaging portion 1672i while elastically deforming.

[0592] Thereafter, as shown in FIG. 105(d), the aligning member 1633 is rotated relative to the flange member 1670 until the rotation stopper 1633l elastically deforms and exceeds the engaging portion 1672i, thereby assembling the aligning member 1633 to the flange member 1670.

[0593] Consider a case where cartridge 7 incorporating coupling member 628 to which alignment member 633 described in Example 6 is attached is mounted with a strong force into image forming apparatus main body 100A. At this time, inverted cone shape 633a of alignment member 633 abuts with a strong force against hemispherical shape 101c of main body drive shaft 101. As shown in Figure 63, retaining portion 633c of Example 6 has a snap-fit ​​shape that extends in the axial direction of coupling member 628.

[0594] If the retaining portion 633c is made of a material that has a snap-fit ​​shape and bends with a small force, there is a concern that the retaining portion 633c may come off the hook portion 672b if the alignment member 633 receives the strong force from the main body drive shaft 101.

[0595] In contrast, the recess 1633k of the alignment member 1633 in this embodiment is fixed to the hook portion 1672b by a groove shape 1633n that is provided on the Z1 direction side of the fitting portion 1633b and that opens upstream in the rotation direction of the coupling member 1628. Even if the alignment member 1633 receives the strong force from the main body drive shaft 101, there is little concern that the alignment member 1633 will come off the flange member 1670. This is because the recess 1633k is not a snap-fit ​​shape, unlike the retaining portion 633c of the sixth embodiment.

[0596] As described above, the base portion 1633r of the rotation stopper 1633l is perpendicular to the holding surface 1633q and is located downstream in the rotational direction of the line passing through the tip of the holding surface 1633q. This shape makes it difficult for the alignment member 1633 to come off the flange member 1670. This is because, if the alignment member 1633 receives a rotational driving force from the main body drive shaft 101 and rotates relative to the flange member 1670, the holding surface 1633q will come into contact with the engagement surface 1672j of the flange member. In this case, a force pulling the alignment member 1633 toward the center of rotation of the flange member 1670 is applied to the rotation stopper 1633l, preventing the alignment member 1633 from coming off the flange member 1670.

[0597] As described above, by using the coupling member 1628 described in this embodiment, it is possible to reduce the risk of the alignment member 1633 coming off the flange member 1670 when the cartridge 7 is attached to the image forming apparatus main body 100A with a strong force.

[0598] In this embodiment, the snap fit is provided on the side of the aligning member 1633, but it may also be provided on the side of the flange member.

[0599] Example 15 The fifteenth embodiment will be described with reference to Figures 107 and 108. Elements corresponding to those in the previous embodiments (especially the sixth embodiment) will be given the same names, and explanations of similarities with the previous elements may be omitted. The following description will focus on differences from the previous elements.

[0600] In the sixth embodiment, a configuration in which the sheet metal member 635 is insert-molded into the flange member 670 has been described. Specifically, as shown in FIG. 73 , a winding portion notch 674h is provided in the winding portion 674b of the base 674, and a winding portion exposed portion 635j, which is a part of the sheet metal member 635, is exposed from the resin portion 634 of the flange member 670. In addition, a connecting hole 635g is provided in the base interior 635a of the sheet metal member 635, and the resin on the front and back of the sheet metal is connected to increase the bonding force between the resin portion 634 and the sheet metal 635. In the sixth embodiment, the driving force receiving surface 673a side of the winding portion notch 674h on the radially inner side of the winding portion 674b is formed in a direction parallel to the axial direction of the flange member 670. Furthermore, the connecting hole 635a is disposed inside the winding portion 674b at a position that does not overlap with the winding portion cutout tapered surface 674j in the Z direction.

[0601] In the shape of Example 6, when the driving force receiving surface 673a receives a driving force from the main body drive shaft 101, the driving force receiving surface 673a and the radially inner notch 674h of the winding portion are oriented close to each other. As a result, stress is concentrated at the corner 674k of the radially inner notch 674h on the driving force receiving surface side (see FIG. 107(a)). Then, the stress is transmitted from the corner 674k on the driving force receiving surface side to the ridge 674l on the driving force receiving surface side (see FIG. 107(b)).

[0602] Therefore, in the sixth embodiment, the strength of the driving force receiving surface side ridge 674l is made sufficiently high to withstand the driving force applied to the driving force receiving surface 673a and the load applied to the base portion 674. The driving force receiving surface side ridge 674l is the ridge of the winding portion cutout tapered surface 674j.

[0603] In this embodiment, the base is configured to have even greater strength. Specifically, in this embodiment, two connecting holes 1735a are arranged parallel to the Z direction on the inside of the winding portion 1774b. Furthermore, each connecting hole 1735a is arranged so that a portion of the connecting hole 1735a overlaps with the driving force receiving surface-side ridge 1774l of the winding portion cutout tapered surface 1774j in the Z direction and in the circumferential direction of the winding portion 1774b (see FIG. 108).

[0604] As described above, the resin part 1739 and the sheet metal member 1735 are most firmly fixed at the connecting hole 1735a.

[0605] The connecting hole 1735a is arranged so that it partially overlaps with the driving force receiving surface side ridge 1774l in the Z direction and in the circumferential direction of the winding portion 1774b. This prevents stress from concentrating on the driving force receiving surface side corner 674k from being transmitted to the driving force receiving surface side ridge 1744l. This more reliably protects the driving force receiving surface side ridge 1744l.

[0606] As a result, it is possible to apply a stronger driving force or load to the driving force receiving surface or the resin portion, and it is also possible to rotate and stop the main body driving shaft 101 more frequently.

[0607] In this embodiment, two connecting holes 1735a are arranged in the Z direction, but the connecting holes 1735a may be arranged so that they partially overlap with the driving force receiving surface side ridges 1774l at both ends in the Z direction and in the circumferential direction of the winding portion 1774b. Therefore, one connecting hole 1735a may be used as shown in FIG. 109.

[0608] Example 16 The sixteenth embodiment will be explained with reference to FIG.

[0609] Elements corresponding to those in the above-described embodiments (especially embodiment 6) are given the same names, and explanations of the same points as the above-described elements may be omitted. The following explanation will focus on the points that are different from the above-described elements.

[0610] In the sixth embodiment, a configuration in which the sheet metal member 635 is insert-molded into the flange member 670 has been described. Specifically, as shown in FIG. 73 , a winding portion notch 674h is provided in the winding portion 674b of the base 674, and a winding portion exposed portion 635j, which is a part of the sheet metal member 635, is exposed from the resin portion 634 of the flange member 670. In addition, a connecting hole 635g is provided in the base interior 635a of the sheet metal member 635, and the resin on the front and back of the sheet metal is connected to increase the bonding force between the resin portion 634 and the sheet metal 635. In the sixth embodiment, the driving force receiving surface 673a side of the winding portion notch 674h on the radially inner side of the winding portion 674b is formed in a direction parallel to the axial direction of the flange member 670. Furthermore, the connecting hole 635a is disposed inside the winding portion 674b at a position that does not overlap with the winding portion cutout tapered surface 674j in the Z direction.

[0611] In the shape of Example 6, when the driving force receiving surface 673a receives a driving force from the main body drive shaft 101, the driving force receiving surface 673a and the radially inner notch 674h of the winding portion are oriented close to each other. As a result, stress is concentrated at the corner 674k of the radially inner notch 674h of the winding portion on the driving force receiving surface side (shown in Figure 107(a)).

[0612] In contrast, in this embodiment, the angle A formed by the corner 1874k of the winding portion notch on the inner periphery of the flange member 1870 on the driving force receiving surface side is an obtuse angle. Therefore, the ridge 1874m of the winding portion notch on the driving force receiving surface side is disposed obliquely with respect to the axis of the flange member 1870 (as shown in FIG. 110).

[0613] 110, an arc shape is provided at corner 1874k on the side of the dynamic receiving surface. This configuration makes it possible to disperse stress concentrated at corner 1874k of the driving force receiving surface of the notched winding portion, compared to Example 6. As a result, it becomes possible to apply a larger driving force or load to the driving force receiving portion (driving force receiving portion) and resin portion 1839, and to rotate and stop main body drive shaft 101 more frequently.

[0614] Example 17 The seventeenth embodiment will be described with reference to FIG.

[0615] Elements corresponding to those in the above-described embodiments (especially embodiment 6) are given the same names, and explanations of the same points as the above-described elements may be omitted. The following explanation will focus on the points that are different from the above-described elements.

[0616] In the sixth embodiment, a configuration in which the sheet metal member 635 is insert-molded into the flange member 670 has been described. Specifically, as shown in FIG. 73 , a winding portion notch 674h is provided in the winding portion 674b of the base 674, and a winding portion exposed portion 635j, which is a part of the sheet metal member 635, is exposed from the resin portion 634 of the flange member 670. In addition, a connecting hole 635g is provided in the base interior 635a of the sheet metal member 635, and the resin on the front and back of the sheet metal is connected to increase the bonding force between the resin portion 634 and the sheet metal 635. In the sixth embodiment, the driving force receiving surface 673a side of the winding portion notch 674h on the radially inner side of the winding portion 674b is formed in a direction parallel to the axial direction of the flange member 670. Furthermore, the connecting hole 635a is disposed inside the winding portion 674b at a position that does not overlap with the winding portion cutout tapered surface 674j in the Z direction.

[0617] 111, two connecting holes 1935a are arranged parallel to the Z direction on the inside of the winding portion 1974b. Each connecting hole 1935a is arranged so that a portion of the connecting hole 1935a overlaps with the driving force receiving surface side ridge 1974l of the winding portion cutout tapered surface 1974j in the Z direction and in the circumferential direction of the winding portion 1774b.

[0618] Also, a ridge 1974m on the driving force receiving surface side of the winding portion notch is disposed obliquely with respect to the axis of the flange member 1970 so that an angle A formed by a corner 1974k on the driving force receiving surface side of the winding portion notch on the inner periphery of the flange member 1870 is an obtuse angle (see FIG. 111). Also, as shown in FIG. 111, a circular arc shape is formed at the corner 1974k on the driving force receiving surface side.

[0619] By using the configuration of this embodiment, it is possible to obtain the effects of both the fifteenth and sixteenth embodiments. It becomes possible to apply a larger driving force to the engaging portion (driving force receiving portion) and the resin portion 1839, and to make the main body driving shaft 101 rotate and stop more frequently.

[0620] Example 18 An explanation will be given of Example 18. Elements having the same or corresponding configurations and functions as those in Example 6 are given the same reference numerals, and detailed explanations will be omitted.

[0621] In the sixth embodiment, the operation of removing the coupling member 628 from the main body drive shaft 101 has been described with reference to FIG.

[0622] As described above, in the sixth embodiment, the coupling member 628 was removed from the main body drive shaft 101 by the following operation.

[0623] When the rotation of the main body drive shaft 101 stops, the drive force receiving surface 673a and the main body drive transmission surface 101b come into contact with each other. In this state, part of the engagement portion 673 is inserted into the main body drive transmission groove 101a (see Figure 68(a)).

[0624] When the cartridge door 104 is opened, the front cartridge lower guide 109 descends, and the drum unit bearing member 39L moves away from the front cartridge positioning portion 110 of the image forming apparatus main body 100A. At this time, the coupling member 628 and the main body drive shaft 101 are tilted by approximately 0.5 to 2 degrees with respect to the installation completion state (Z direction) (shown in Figure 68(b)).

[0625] When removal of the cartridge 7 from the image forming apparatus main body 100A begins, the removal tapered surface 673e of the engaging portion 673 abuts against the main body-side removal taper 101i. When the removal tapered surface 673e abuts against the main body-side removal taper 101i, the base 674 begins to elastically deform, and the engaging portion 673 moves radially outward along the main body-side removal taper 101i (shown in Figure 68(c)).

[0626] When coupling member 628 is further removed from main body drive shaft 101, the state becomes similar to that shown in Figure 65(a), and base portion 674 further elastically deforms, moving engaging portion 673 to the outer diameter of shaft portion 101f of main body drive shaft 101. When engaging portion 673 moves to the outer diameter of shaft portion 101f, coupling member 28 can be removed from main body drive shaft 101, as shown in Figure 68(d).

[0627] Furthermore, when the coupling member 628 is removed from the main body drive shaft 101, the elastic deformation of the base portion 674 is released, and the position of the engaging portion 673 also returns to the position before the elastic deformation, as shown in FIG. 68(e).

[0628] By the above operation, in the sixth embodiment, the coupling member 628 is removed from the main body drive shaft 101.

[0629] Furthermore, in Example 6, as described above, base portion 674a is arranged on the upstream side in the rotation direction of flange member 670 with respect to a line drawn from inner diameter end 673b of driving force receiving surface 673a in a direction perpendicular to driving force receiving surface 673a when viewed from the Z direction (see FIG. 67). As a result, main body driving force receiving surface 101b of main body drive shaft 101 comes into contact with driving force receiving surface 673a of engaging portion 673, and when rotation occurs, base portion 674 is retracted and winding portion 674b winds around shaft portion 101f.

[0630] Even if the rotation of the main body drive shaft 101 stops in the above-described wound state, the contact between the driving force receiving surface 101b and the driving force receiving surface 673a is maintained, so the winding portion 674b maintains its state of being wound around the shaft portion 101f.

[0631] As described above, in Example 6, the driving force receiving surface 673a has a shape twisted around the center of the rotation axis of the flange member 670. The twisting direction is such that the outer side (Z1 direction side) of the driving force receiving surface 673a of the photosensitive drum unit 30 is disposed upstream in the rotation direction of the photosensitive drum 1 relative to the inner side (Z2 direction side).

[0632] In this state, when attempting to remove the coupling member 628 from the main body drive shaft 101, the outer side (Z1 direction side) of the driving force receiving surface 673a is positioned upstream in the rotational direction relative to the inner side (Z2 direction side), so the driving force receiving surface 673a is positioned in a direction that hinders the removal operation.

[0633] As a result, when attempting to remove the coupling member 628 from the main body drive shaft 101 in the removal operation of the sixth embodiment, the removal load is greater than the insertion load.

[0634] In contrast, in this embodiment, the main body drive shaft 101 is configured to rotate in the reverse direction between the time when the rotational drive of the main body drive shaft 101 stops and the time when the cartridge 7 starts to be removed from the image forming apparatus main body 100A. As a result, the cartridge 7 is removed from the image forming apparatus main body 100A after the winding portion 674b is released from the shaft portion 101f, thereby reducing the removal load.

[0635] As a method for reverse rotation, the main body drive shaft 101 may be rotated in reverse by a link mechanism or the like in conjunction with the opening operation of the cartridge door 104, or the motor that is the drive source of the main body drive shaft 101 may be configured to rotate in reverse.

[0636] The configuration of this embodiment in which the main body drive shaft 101 is rotated in the reverse direction during the removal operation can provide the same effect not only in the sixth embodiment but also in the coupling member configurations described in the first to nineteenth embodiments.

[0637] Example 19 Next, another embodiment will be described with reference to Figures 112 to 115, 120, and 121. First, the mounting configuration for mounting the cartridge 7 to the image forming apparatus main body 100A will be described. Elements corresponding to those in the above-mentioned embodiment will be given the same names, and explanations of similar points to the above-mentioned elements may be omitted. Regarding these, the explanation will focus on points that are different from the above-mentioned elements.

[0638] FIG. 112 is a cross-sectional perspective view of flange member 2170 and engagement member 2173. FIG.

[0639] FIG. 113 is a cross-sectional view of the coupling member 2128.

[0640] FIG. 114 is a cross-sectional view of the coupling member 2128 when the drive receiving portion 2173a receives drive from the main body drive shaft 2210. As shown in FIG.

[0641] FIG. 115 is a cross-sectional view showing the operation of the process of mounting the coupling member 2128 to the main body drive shaft 2210 when the phases of the driving force receiving portion (driving force receiving surface) 2173a and the driving force transmission groove 2210a are not aligned.

[0642] FIG. 120 is a perspective view showing the shape of the main body drive shaft 2210.

[0643] FIG. 121 is a perspective view showing the shape of the cartridge 7. As shown in FIG.

[0644] [Configuration of coupling member and main body drive shaft] The configuration of the coupling member and the main body drive shaft will be explained with reference to Figures 112, 113, 114 and 120.

[0645] A coupling member 2128 is attached to the front end of the photosensitive drum 1 in the insertion direction of the cartridge 7, and a main body drive shaft 2210 is provided at a position corresponding to the coupling member 2128 of the image forming apparatus main body 100A.

[0646] 113, the coupling member 2128 has a flange member 2170 attached to the photosensitive drum 1, and an engaging member (driving force receiving member) 2173 that receives drive from the main body drive shaft 2210. Furthermore, the coupling member 2128 has a retaining member 2177 that restricts movement of the engaging member 2173 in the axial direction of the photosensitive drum 1.

[0647] As shown in FIG. 112, the flange member 2170 has an attachment portion 2172 that is attached to the inner periphery of the photosensitive drum 1, a cylindrical portion 2171 that protrudes from the attachment portion 2172, and an engagement member attachment portion 2172a that is groove-shaped and for attaching an engagement member 2173.

[0648] The engaging member 2173 is a driving force receiving member having a driving force receiving portion provided on its surface. As will be described in detail later, it also serves as a support portion that supports the driving force receiving portion 2173a so that it can move at least in the radial direction of the coupling member.

[0649] The flange member 2170 is a member to which the driving force is transmitted from the engagement member 2173. In this embodiment, the flange member 2170 is fixed to the inner periphery of the photosensitive drum 1, and the driving force is transmitted from the flange member 2170 to the photosensitive drum 1.

[0650] There is a gap between the engaging member 2173 and the flange member 2170, and the engaging portion 2173 is configured to be movable in the radial direction and the circumferential direction relative to the flange member 2170 within a certain range.

[0651] An outer peripheral surface 2171a of the cylindrical portion 2171 is used as a sliding surface that is rotatably supported by a bearing portion 29a of a bearing member 29 attached to the cleaning frame 14 of the cleaning unit 13. An inner peripheral surface 2171b of the cylindrical portion 2171 is used as a support portion that supports the main body drive shaft 2210.

[0652] A sheet metal member (plate-shaped metal) having spring properties (elasticity) is used for the engaging member 2173. In other words, the engaging member 2173 is a plate-shaped part made of metal, or in other words, a leaf spring.

[0653] As shown in FIG. 114, the engagement member 2173 has a driving force receiving portion 2173a that comes into contact with a driving transmission groove 2210a, which is a groove-shaped groove provided in the main body drive shaft 2210, and receives a driving force (rotational force). The engagement member 2173 is attached to the flange member 2170 so that the driving force receiving portion 2173a is movable in the radial direction and rotational direction of the photosensitive drum. In this embodiment, as shown in FIG. 114, a base portion 2173b of the engagement member 2173 is attached to a groove-shaped engagement member attachment portion 2172a of the flange member 2170 using a spring. In this way, the engagement member 2173 is attached to the flange member 2170 so that the driving force receiving portion 2173a is movable in the radial direction and rotational direction of the photosensitive drum 1. In other words, the base portion 2173b is a supported portion (attached portion) supported by the attachment portion 2172a of the flange member 2170.

[0654] The engaging member 2173 has a bent portion 2173k bent at an angle of approximately 90°. A driving force receiving portion 2173a is provided at a portion (first portion) on the tip side of the engaging member 2173, with the bent portion 2173k as the boundary. Meanwhile, a base portion 2173b is provided at a portion (second portion of the engaging member) on the rear side of the engaging member 2173, with the bent portion 2173k as the boundary. The length of the second portion is longer than the length of the first portion.

[0655] The first and second portions of the engaging member 2173 extend in different directions. That is, the extending directions of the first and second portions intersect. The first portion of the engaging member 2173 extends from the bent portion 2173k at least radially inward. In other words, the first portion of the engaging member 2173 is a protrusion that protrudes at least radially inward.

[0656] On the other hand, the second portion of the engaging member 2173 extends from the bent portion 2173k at least toward the circumferential direction of the coupling member (more specifically, toward the upstream side in the rotational direction). The second portion of the engaging member 2173 is an extending portion that extends in a direction different from the protruding direction of the first portion of the engaging member 2173, and is also a portion that supports the first portion of the engaging member 2173. Furthermore, as will be described in detail later, the second portion of the engaging member 2173 is an elastically deformable deformation portion, and deformation of the second portion allows the first portion of the engaging member 2173 to move at least in the radial direction of the coupling member.

[0657] In addition, as shown in Figure 113, the anti-slip member 2177 is fixed to the flange member 2170, and by sandwiching the engaging member 2173 between the flange member 2170 and the anti-slip member 2177, movement of the engaging member 2173 in the axial direction of the photosensitive drum 1 is restricted.

[0658] In this embodiment, thermal crimping is used as the fixing means (fixing method) for fixing the retaining member 2177 to the flange member 2170. That is, after the crimping hole 2177f of the retaining member 2177 is passed through the crimping boss 2170f of the flange member 2170, the tip of the crimping boss 2170f is thermally crimped to fix the flange member 2170 and the retaining member 2177. However, other fixing methods such as welding, press fitting, snap fitting, etc. may also be used.

[0659] As shown in FIG. 114, the engaging member 2173 has a first contact portion 2173c and a second contact portion 2173d. The first contact portion 2173c is disposed upstream of the driving force receiving portion 2173a in the rotational direction and radially outward. The second contact portion 2173d is formed on a surface different from (the surface opposite to) the surfaces on which the first contact portion 2173c and the driving force receiving portion 2173a are provided. The second contact surface 2173d is disposed further radially outward than the first contact portion 2173c.

[0660] Furthermore, the flange member 2170 has a first contact portion 2173c and a second contact portion 2173d, and a first wall surface portion 2170g and a second wall surface portion 2170h that come into contact with the first and second contact portions 2173c and 2173d, respectively, when the driving force receiving portion 2173a is driven.

[0661] The first wall surface portion 2170g is a transmitted portion (transmitted surface) to which the driving force is transmitted from the engaging member 2173. The first wall surface portion 2170g is disposed radially outward of the driving force receiving portion 2173a.

[0662] 120, the main body drive shaft 2210 has a drive transmission groove 2210a and a supported portion 2210d. The drive transmission groove 2210a is a groove shape (recessed shape) that corresponds to the drive force receiving portion 2173a provided on the outer peripheral surface of the main body drive shaft 2210. The supported portion 2210d is a portion that is supported by the inner peripheral surface 2171b of the flange member 2170.

[0663] [Attaching the coupling member to the main body drive shaft] The attachment of the coupling member 2128 to the main body drive shaft 2210 will be described with reference to FIGS.

[0664] First, the cartridge 7 is inserted in the direction of the arrow until the insertion tapered surface (chamfered shape) 2173e provided on the upstream side of the driving force receiving portion 2173a in the insertion direction comes into contact with the spherical shape (hemispherical shape 2201d) at the tip of the main body driving shaft 2210, as shown in Figure 115(a).

[0665] When the cartridge 7 is further inserted in the direction of the arrow, the engaging member 2173 utilizes its spring property starting from the base portion 2173b and deforms so that the insertion tapered surface 2173e fits the hemispherical shape 2201c at the tip. The engaging member 2173 deforms so that the driving force receiving portion 2173a moves radially outward from the photosensitive drum 1.

[0666] Then, as shown in FIG. 115(b), by supporting the bearing portion 2201d by the support portion (inner peripheral portion 2171b) of the flange member (cylindrical portion 2171), the coupling member 2128 is inserted to the mounting completion position relative to the main body drive shaft 2210.

[0667] 115(c), as the main body drive shaft 2210 rotates, the drive transmission groove 2210a and the drive force receiving portion 2173a become in phase with each other. At this time, the state in which the engagement member 2173 was deformed radially outward of the flange member 2170 in FIG. 115(b) is released, and the drive force receiving portion 2173a enters the drive transmission groove 2210a.

[0668] Then, as shown in FIG. 114, the drive transmission groove 2210a abuts against the drive force receiving portion 2173a. This allows the rotational drive force from the main body drive shaft 2210 to be transmitted to the coupling member 2128, thereby rotating the photosensitive drum 1. At this time, the engaging member 2173 first moves due to the driving force of the main body drive shaft 2210 until the first abutment portion 2173c abuts against the first wall surface portion 2170g. When the first abutment portion 2173c abuts against the first wall surface portion 2170g, a rotation moment is generated in the engaging member 2173, with the first abutment portion 2173c as a fulcrum, due to the driving force received by the driving force receiving portion 2173a. However, the abutment of the second abutment portion 2173d against the second wall surface portion 2170h suppresses deformation of the engaging member 2173. This allows the driving force received by the drive force receiving portion 2173a to be stably transmitted to the photosensitive drum 1.

[0669] Next, we will explain how to mount the cartridge 7 when the driving force receiving portion 2173a and the driving force transmission groove 2210a are in phase. First, the cartridge 7 is mounted in the direction of the arrow, and the insertion tapered surface 2173e provided on the upstream side of the driving force receiving portion 2173a in the insertion direction comes into contact with the hemispherical shape 2201c at the tip of the main body drive shaft 2210, as shown in Figure 115(a).

[0670] When the cartridge 7 is further inserted in the direction of the arrow, the spring property of the engaging member 2173 causes the driving force receiving portion 2173a to deform and move radially outward from the flange member 2170. The coupling member 2128 is then inserted into the main body drive shaft 2210 at the complete installation position. At this time, the driving force receiving portion 2173a and the drive transmission groove 2210a are aligned in phase, so the deformation of the engaging member 2173 is released, and the main body drive shaft 2210 does not rotate, resulting in the state shown in Figure 115(c). After the state shown in Figure 115(c) is reached, the situation is the same as when the driving force receiving portion 2173a and the drive transmission groove 2210a are not aligned in phase.

[0671] The above is a description of the operation in the process of attaching the coupling member 2128 to the main body drive shaft 2210.

[0672] [Releasing the coupling member from the drive shaft on the main body side] As shown in FIG. 115(d), a removal tapered surface (chamfered shape) 2173f is provided on the downstream side of the driving force receiving portion 2173a in the insertion direction, and a main body-side removal tapered surface (chamfered shape) 2210i is provided on the tip side of the drive transmission groove 2210a of the main body drive shaft 2210. As a result, when the cartridge 7 is removed in the direction of the arrow, the removal tapered surface 2173f and the main body-side removal tapered surface 2210i come into contact. When the cartridge 7 is further removed in the direction of the arrow, the engaging member 2173 utilizes its spring property starting from the base portion 2173b to deform so that the insertion tapered surface 2173e fits along the main body-side removal tapered surface 2210i. The engaging member 2173 deforms so that the driving force receiving portion 2173a moves radially outward from the photosensitive drum 1. When the cartridge 7 is further removed in the direction of the arrow, the main body drive shaft 2210 and the engaging member 2173 no longer come into contact with each other, the deformed state of the engaging member 2173 is released, and the driving force receiving portion 2173a returns to its initial position.

[0673] As described above, by moving the driving force receiving portion 2173a radially outward, attachment / detachment and driving force transmission can be performed without using a mechanism for retracting the main body driving shaft 2210 in the axial direction.

[0674] It is preferable that the thickness of engaging member 2173 satisfy the following condition: In order for engaging member 2173 to stably receive driving force, it is desirable that engaging member 2173 has a portion with a thickness of 0.1 mm or more, more preferably 0.2 mm or more. In particular, it is desirable that the vicinity of the portion where driving force receiving portion 2173a is provided (first portion of engaging member 2173) has the above thickness.

[0675] Furthermore, in order for the engaging member 2173 to deform smoothly when the coupling member 2128 is coupled to and separated from the main body drive shaft 2210, it is preferable that the engaging member 2173 has a portion that is 0.7 mm or less, more preferably 0.5 mm or less. In particular, it is preferable that the thickness of the periphery of the base portion 2173b where the engaging member 2173 deforms (the second portion of the engaging member 2173) be within the above range.

[0676] The thickness of the engaging member 2173 does not need to be constant, and the thickness may be different between the portion that receives the driving force and the portion that deforms.

[0677] If the engaging member 2173 is configured to have a constant thickness, it is desirable that both the upper and lower limits of the preferred thickness described above be satisfied.

[0678] Example 20 The cartridge and electrophotographic image forming apparatus according to this embodiment will be described with reference to Figure 116. Elements corresponding to those in the previous embodiment will be given the same names, and explanations of similarities with the previous elements will be omitted. Regarding these, the explanation will focus on differences from the previous elements.

[0679] In Example 19, the driving force receiving portion 2173a was arranged as follows: That is, as shown in Fig. 114, if a straight line (the dashed line in Fig. 114) is drawn along the surface of the driving force receiving portion 2173a in a cross section perpendicular to the axis of the photosensitive drum 1, this straight line passes near the axis (center) of the photosensitive drum 1.

[0680] That is, the first portion where the driving force receiving portion 2173a is provided extends substantially along the radial direction of the flange member. In other words, the first portion of the sheet metal member 213 where the driving force receiving portion 2173a is provided extends in a direction substantially perpendicular to the circumference.

[0681] In contrast to this, in this embodiment, the radially outer side of the driving force receiving portion 2273a is disposed downstream in the rotation direction relative to the radially inner side, as shown in Figure 116. In other words, in the engaging member 2273 of this embodiment, the extending direction of the driving force receiving portion 2273a is inclined relative to the radial direction.

[0682] Furthermore, the drive transmission groove 2310a of the main body drive transmission shaft 2310 has a shape corresponding to the drive force receiving portion 2273a. The drive transmission groove 2310a is inclined with respect to the radial direction.

[0683] As a result, when a driving force F221 is applied to the driving force receiving portion 2273a from the main body drive shaft 2310, a reaction force F222 is generated in the driving force receiving portion 2273a. The reaction force F222 has a component F22h in a direction parallel to the driving force receiving portion 2273a and a component F22v in a direction perpendicular to the driving force receiving portion 2273a. Of these, component F22h serves to pull the driving force receiving portion 2273a inward.

[0684] This allows the second contact portion 2273d of the engaging member 2273 to more stably contact the second wall surface portion 2270h of the flange member 2270. As a result, the photosensitive drum 1 can be driven stably.

[0685] Example 21 The cartridge and the electrophotographic image forming apparatus will be described with reference to Figures 118, 119, and 120. Elements corresponding to those in the 19th embodiment are given the same names, and explanations of the same points as the elements described above may be omitted. The explanation will focus on the points that are diffe...

Claims

1. 1. A drum unit for use in a cartridge, comprising: A photosensitive drum; a coupling located at an end of the photosensitive drum and rotatable around an axis; and The coupling is a driving force receiving member having a protrusion configured to receive a driving force from the outside of the drum unit; a drive transmission member configured to transmit the drive force from the drive force receiving member to the photosensitive drum, the drive transmission member including a transmission portion configured to receive the drive force by contacting the protrusion; Equipped with the driving force receiving member is movable between a first position and a second position relative to the driving force transmission member, a tip end of the protrusion is located closer to the axis of the coupling when the driving force receiving member is in the first position than when the driving force receiving member is in the second position, When the driving force receiving member is in the first position, the tip of the protrusion is located closer to the axis of the coupling than the transmission portion.

2. 2. The drum unit according to claim 1, wherein the driving force receiving member has an extending portion extending in the direction of the axis of the coupling, and the protrusion protrudes from the extending portion.

3. the drive transmission member has a backup portion configured to contact the protrusion to prevent the protrusion from moving in the rotational direction of the coupling relative to the drive transmission member, 3. The drum unit according to claim 1, wherein when the driving force receiving member is in the first position, a tip of the protrusion is located closer to the axis of the coupling than the backup portion.

4. The drum unit according to claim 1 , wherein the coupling includes a plurality of the driving force receiving members.

5. The drum unit according to claim 1 , wherein the driving force receiving member includes a plurality of the protrusions.

6. 6. The drum unit according to claim 1, wherein the protrusion is configured to be elastically biased from the second position toward the first position.

7. the drive transmission member includes a cylindrical portion; The drum unit according to claim 1 , wherein the protrusion is located inside the cylindrical portion.

8. The drum unit according to claim 7 , wherein a part of the cylindrical portion is located inside the photosensitive drum, and a part of the cylindrical portion is located outside the photosensitive drum.

9. 9. The drum unit according to claim 1, wherein when the driving force receiving member is in the first position, the protrusion protrudes toward the axis of the coupling.

10. 10. The drum unit according to claim 1, wherein an open space is formed between the axis of the coupling and the protrusion when the driving force receiving member is in the first position.

11. The drum unit according to claim 1 , wherein at least a part of the protrusion is located inside the photosensitive drum.

12. 12. The drum unit according to claim 1, wherein the drive transmission member is fixed to the photosensitive drum.

13. A cartridge, a rotating body configured to carry a developer on its surface; a frame that rotatably supports the rotating body; a coupling configured to transmit a driving force toward a rotating body and rotatable about an axis; and The coupling is a driving force receiving member having a protrusion configured to receive the driving force from the outside of the cartridge; a drive transmission member configured to transmit the drive force from the drive force receiving member to the rotating body, the drive transmission member including a transmission portion configured to receive the drive force by contacting the protrusion; Equipped with the driving force receiving member is movable between a first position and a second position relative to the driving force transmission member, a tip end of the protrusion is located closer to the axis of the coupling when the driving force receiving member is in the first position than when the driving force receiving member is in the second position, When the driving force receiving member is in the first position, a tip of the protrusion is located closer to the axis of the coupling than the transmission portion.

14. 14. The cartridge according to claim 13, wherein the driving force receiving member has an extending portion extending in the axial direction of the coupling, and the protrusion protrudes from the extending portion.

15. the drive transmission member has a backup portion configured to contact the protrusion to prevent the protrusion from moving in the rotational direction of the coupling relative to the drive transmission member, 15. A cartridge according to claim 13, wherein when the driving force receiving member is in the first position, a tip of the protrusion is positioned closer to the axis of the coupling than the backup portion.

16. 16. A cartridge according to claim 13, wherein the coupling includes a plurality of the driving force receiving members.

17. 16. A cartridge according to claim 13, wherein the driving force receiving member includes a plurality of the protrusions.

18. 18. A cartridge according to any one of claims 13 to 17, wherein the protrusion is configured to be resiliently biased from the second position towards the first position.

19. the drive transmission member includes a cylindrical portion; 19. A cartridge according to claim 13, wherein the protrusion is located inside the cylindrical portion.

20. the cartridge further comprises a gear; 20. The cartridge according to claim 13, wherein the coupling is configured to transmit the driving force to the rotating body via the gear.

21. 21. The cartridge according to claim 13, wherein the rotating body comprises a developing roller.

22. the cartridge has a supply roller configured to supply developer to the developing roller; 22. The cartridge of claim 21, wherein the coupling is configured to transmit the driving force to the developer roller via the supply roller.

23. 21. The cartridge according to claim 13, wherein the rotating body comprises a photosensitive drum.

24. 24. A cartridge according to any one of claims 13 to 23, wherein when the driving force receiving member is in the first position, the protrusion protrudes toward the axis of the coupling.

25. 25. A cartridge according to claim 13, wherein an open space is formed between the axis of the coupling and the protrusion when the driving force receiving member is in the first position.

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