JP4604063B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to a drive transmission device in which a drive shaft and a driven shaft are arranged so as to be able to contact and separate on the same axis and transmit driving from the drive shaft to the driven shaft via a drive transmission means, and an image forming apparatus including the drive transmission device.

  In an image forming apparatus such as a copying machine, a developing device, a cleaner, or an injection charger has a consumable member such as a developer, a cleaning blade, or an injection agent. It is common to adopt a simple configuration. These units such as a developing device, a cleaner, and an injection charger are provided with a rotating body (driven body) such as a developing sleeve, a developer conveying screw, a waste toner conveying screw, and an injecting sleeve.

  As a method of driving the rotating body in the unit, a method of transmitting a driving force from the main body side to the unit side by a gear, a coupling (driving joint) or the like by arranging a driving source in the apparatus main body is general.

  By the way, in an image forming apparatus that employs a method in which a process cartridge is attached / detached from the front surface of the apparatus main body, the attaching / detaching direction of the process cartridge is parallel to the axis of the rotating body. In this case, a coupling (driving joint) that is simple in design and small in installation space is generally employed as the connecting means of the driving unit. Here, as a coupling (driving joint), a coupling member having a plurality of claw portions or uneven portions at opposite ends of a driving shaft and a driven shaft arranged on the same axis is known. .

  However, the conventional coupling (driving joint) has the following problems.

  That is, the drive shaft and the driven shaft are arranged on the same axis, but when the configuration in which these shafts are used as positioning members cannot be adopted, the axes of these shafts are slightly due to component tolerances. A gap occurs. If there is a deviation of this axis, vibration will be applied to the process cartridge which is the driven unit.

  That is, when there is a deviation in the axis, the contact of the claw portions as a plurality of drive transmission portions is not uniform, and thus the drive transmission force of each claw portion is unbalanced. When an imbalance occurs in the drive transmission force, a surplus force acts in a certain direction in a plane perpendicular to the axis, in addition to transmitting torque to the driven shaft. Since the direction of the extra force is not constant but changes while rotating, the vibration acts on the process cartridge in the rotation cycle. When vibration is applied to the process cartridge, for example, a change occurs in the development SD gap, causing problems such as image density unevenness.

  The present invention has been made in view of the above problems, and the object of the present invention is to prevent vibration of the driven unit even if there is an axial deviation between the driving shaft and the driven shaft. A drive transmission device and an image forming apparatus including the drive transmission device are provided.

In order to achieve the above object, according to the present invention, a rotatable image carrier and a rotating member having a rotation shaft for forming an image on the image carrier are integrated, and can be attached to and detached from the image forming apparatus. An image forming unit, an image carrier shaft provided in the image forming apparatus and fitted to the image carrier, a drive shaft provided in the image forming apparatus for applying a driving force to the rotating member, and the drive shaft In an image forming apparatus having a drive connecting member that transmits a driving force to the rotation shaft, the position of the image forming unit with respect to the image forming apparatus is determined by fitting the image carrier shaft to the image carrier, and the drive The connecting member is attached to one of the drive shaft and the rotating shaft with flexibility in the axial direction, the circumferential direction of the shaft, and the radial direction of the shaft, and the other shaft has flexibility in the radial direction and axial direction of the shaft. Engage with the cylindrical part of the drive connecting member Some of the leading end of the cylindrical portion and wherein the protruding toward the upstream side in the insertion direction of the other shaft. A rotatable image bearing member; a rotating member having a rotating shaft for forming an image on the image bearing member; and a rotating force attached to the rotating shaft from the driving shaft of the image forming apparatus to the rotating shaft. An image bearing member shaft provided in the image forming apparatus is engaged with the image bearing member, and the drive shaft and the driving coupling member are engaged to form an image. In a process cartridge that can be mounted on the forming apparatus, the position of the image forming unit with respect to the image forming apparatus is determined by fitting the image carrier shaft to the image carrier, and the drive shaft is in the radial direction and the axial direction of the shaft. The drive coupling member engages with the cylindrical portion of the drive coupling member with a degree of freedom, and the drive coupling member is attached with a degree of freedom in the axial direction of the rotating shaft, the circumferential direction of the shaft, and the radial direction of the shaft . Part of the tip is part of the drive shaft Characterized in that it projects toward the upstream side of the incoming direction.

  As is clear from the above description, according to the present invention, the drive transmission means can be inserted / removed / engaged in accordance with the contact / separation of the drive shaft and the driven shaft. Even if there is an axial deviation, it is possible to prevent the driven unit from being vibrated.

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

<Embodiment 1>
FIG. 13 shows a cross-section of a full-color copying machine as an image forming apparatus according to the present invention. This full-color copying machine is an apparatus that forms a full-color image by superposing four color toners of yellow, magenta, cyan, and black. .

  In FIG. 13, 10Y, 10M, 10C, and 10K are yellow, magenta, cyan, and black image forming units, respectively. FIG. 14 is an enlarged view of one station of the image forming unit.

  Thus, the recording paper stored in the cassette 1 reaches the registration roller 3 after being fed by the paper feeding unit 2, and is skewed and the like is corrected by the registration roller 3 to be transferred to the transfer belt 4 at an appropriate timing. It is sent out towards. During this time, latent images corresponding to the respective colors are formed on the photosensitive drums 11Y, 11M, 11C, and 11K by image information signals sent from a document reading device (not shown) or an output device (not shown) of a computer. .

  On the other hand, the recording paper fed from the registration roller 3 is electrostatically attracted onto the transfer belt 4 and is conveyed by the transfer belt 4 while passing under the color image forming units 10Y, 10M, 10C, and 10K.

  In each of the image forming units 10Y, 10M, 10C, and 10K, exposure LED heads 12Y, 12M, 12C, and 12K, and developing units 13Y, 13M, and 13C, around photosensitive drums 11Y, 11M, 11C, and 11K that are image carriers. 13K and injection chargers 14Y, 14M, 14C, and 14K are arranged, and toner images of the respective colors are formed on the surfaces of the photosensitive drums 11Y, 11M, 11C, and 11K by an electrophotographic process. The toner images of the respective colors are sequentially transferred onto the recording paper by the action of the transfer means 5Y, 5M, 5C, and 5K at the transfer portion where the transfer belt 4 and the photosensitive drums 11Y, 11M, 11C, and 11K are close to each other.

  The recording paper onto which the four color toner images have been transferred is peeled off from the transfer belt 4 by the curvature separation and conveyed to the fixing unit 6, and is heated and pressed by the fixing unit 6 to receive the fixing of the toner image. The sheet is discharged onto the paper tray 7 and the copying operation is completed.

  Next, the process cartridge 21 will be described with reference to FIGS. FIG. 15 is a plan sectional view showing the configuration of the process cartridge and its drive system.

  The process cartridge 21 includes a photosensitive drum 11, a developing device 13, and an injection charger 14, which are integrally supported via kit side plates 22 and 23 as shown in FIG. The process cartridge 21 is configured to be detachable in the front-rear direction with respect to the apparatus main body, and can be replaced integrally or partially replaced and maintained.

  The photosensitive drum 11 is not positioned on the kit side plates 22 and 23, but is positioned by being fitted to the drum shaft 51 when the photosensitive drum 11 is mounted on the apparatus main body. On the other hand, the developing device 13 and the injection charger 14 are fixed to the kit side plates 22 and 23. The bearing portions 24 and 25 of the kit side plates 22 and 23 are fitted to the drum shaft 51, and the pin 23a protruding from the kit side plate 23 is fitted to the short diameter portion of the long hole portion 52a of the main body side plate 52. As a result, the kit side plates 22 and 23, the developing device 13 and the injection charger 14 are positioned.

  The developing sleeve 13a of the developing device 13 and the injecting sleeve 14a of the injecting charger 14 are assembled to the kit side plates 22 and 23 with the distances between the bearing portions 24 and 25 adjusted in advance with high accuracy. As a result, the developing sleeve 13a and the injection sleeve 14a are positioned with high accuracy in the radial direction with respect to the drum shaft 51 when the process cartridge 21 is mounted on the apparatus main body. Since the photosensitive drum 11 is also positioned with respect to the drum shaft 51, the clearance (SD gap) between the developing sleeve 13a and the injection sleeve 14a and the surface of the photosensitive drum 11 is set with high accuracy.

  Incidentally, the drive shafts 81 and 91 shown in FIG. 15 are shafts for driving the developing sleeve 13a and the injection sleeve 14a, respectively, and these are arranged coaxially with respect to the developing sleeve 13a and the injection sleeve 14a, respectively. The drive shafts 81 and 91 are provided with electromagnetic clutches 83 and 93, respectively, which can rotate at a predetermined timing. In addition, couplings 61 and 71 are respectively attached to the tips of the developing sleeves 13a and the injection sleeve 14a, and are driven from the drive shafts 81 and 91 to the developing sleeve 13a and the injection sleeve 14a by the couplings 61 and 71, respectively. Power is transmitted. Thus, the developing sleeve 13a and the injection sleeve 14a are rotating members that rotate.

  Next, the configuration of the drive transmission unit will be described in detail.

  1 is a cross-sectional view of the developing sleeve and its drive shaft (cross-sectional view taken along line DD in FIG. 14), and FIG. 2 is a cross-sectional view taken along line AA in FIG. 1 (cross-sectional view taken along line EE in FIG. 14). is there. In this embodiment, the drive input unit of the developing unit 13 and the injection charger 14 have the same configuration, and therefore only the drive transmission unit in the developing unit 13 will be described below.

  The driving shaft 81 and the sleeve shaft 31 of the developing sleeve 13a are respectively provided with pins 82 and 32 projecting from the outer peripheral portion, and at positions corresponding to the pins 82 and 32 of the coupling 61 (driving connecting member). A groove 61a and a hole 61b are respectively formed. The driving force is transmitted by engaging the pin 82 with the groove 61a and the pin 32 with the hole 61b. The sleeve 61 side of the coupling 61 is a hole 61b, and the drive shaft 81 side is a groove 61a opened in the axial direction. The coupling 61 is attached to the sleeve shaft 31, and the drive shaft This is because 81 can be freely inserted and removed.

  The coupling 61 has cylindrical portions 61c and 61d, and the front end portions of the drive shaft 81 and the sleeve shaft 31 are inserted therein. Here, the outer diameter d1 of the drive shaft 81 is φ6 mm, whereas the inner diameter D1 of the cylindrical portion 61c of the coupling 61 is set to φ7 mm. Further, the outer diameter d2 of the sleeve shaft 31 is φ8 mm, whereas the inner diameter D2 of the cylindrical portion 61d of the coupling 61 is set to φ8.5 mm. Therefore, large radial play (backlash) is formed between the drive shaft 81 and the sleeve shaft 31 and the coupling 61. Incidentally, as the pins 82 and 32 inserted through the drive shaft 81 and the sleeve shaft 31, respectively, those having a diameter of 2 mm are used.

  Further, play (backlash) is formed in the axial direction between the pin 82 and the groove 61a and between the pin 32 and the hole 61b. The axial play (backlash) δz1 between the pin 82 of the drive shaft 81 and the groove 61a is 2 mm. On the other hand, the thrust width z2 of the pin 32 of the sleeve shaft 31 is 2 mm, whereas the thrust width Z2 of the hole 61b is 3 mm, so that there is play (backlash) between the pin 32 and the hole 61b. Is 0.5 mm on one side.

  As described above, the play (backlash) in the radial direction is provided between the drive shaft 81 and the sleeve shaft 31 and the coupling 61. Further, play (backlash) in the axial direction is provided between the pin 82 and the groove 61a of the drive shaft 81 and between the pin 32 and the hole 61b. With this configuration, the coupling 61 can swing with respect to the drive shaft 81 and the sleeve shaft 31.

  3 and 4 (cross-sectional view taken along line BB in FIG. 3) schematically show how the coupling 61 can swing freely. In FIG. 3, when the x axis is perpendicular to the plane of the paper, the y axis is the up and down direction, and the z axis is in the left and right direction, it can be seen that the sleeve shaft 31 can swing around the x axis with respect to the coupling 61. In FIG. 4, it can be seen that the sleeve shaft 31 is swingable about the y-axis. Since the x-axis and the y-axis are orthogonal to each other, it can be seen that the sleeve shaft 31 can swing freely with an intersection O2 between the pin 32 and the sleeve shaft 31 as a fulcrum. Similarly, it can be seen that the drive shaft 81 can swing freely with the intersection point O1 between the axes of the drive shaft 81 and the pin 82 as a fulcrum.

  FIG. 5 is a diagram showing a state in which the drive shaft 81 and the sleeve shaft 31 are displaced from each other. As described above, since the sleeve shaft 31 is not directly positioned with respect to the drive shaft 81, an axial line misalignment (core misalignment) is generated by an amount obtained by accumulating the component tolerances. The axial deviation e shown in FIG. 5 is 0.5 mm.

  Thus, in the present embodiment, since the drive shaft 81 and the sleeve shaft 31 are coupled by the swingable coupling 61, there is an axial deviation (core misalignment) between the drive shaft 81 and the sleeve shaft 31. Even in such a case, since the driving force is smoothly transmitted from the driving shaft 81 to the sleeve shaft 31 by the coupling 61, no vibration is generated in the process cartridge 21 which is a driven unit. The reason for this will be described below.

  If there is an axial deviation (center misalignment) between the drive shaft 81 and the sleeve shaft 31, the coupling 61 is inclined as shown in FIG. Here, the axis L of the coupling 61 intersects both the intersection O1 of each axis of the pin 82 and the drive shaft 81 and the intersection O2 of each axis of the pin 32 and the sleeve shaft 31.

  Thus, when the drive shaft 81 rotates, the coupling 61 can rotate while maintaining an inclined posture. This is because the coupling 61 and the drive shaft 81 are swingable in two axial directions as described with reference to FIGS. The relationship with the sleeve shaft 31 is also the same.

  In this configuration, the drive shaft 81 and the sleeve shaft 31 and the axis 61 of the coupling 61 are connected to each other at the portion where the drive is transmitted (the thrust position where the pin 82 and the groove 61a and the pin 32 and the hole 61b engage). Intersect. For this reason, the pin 82, the groove portion 61a, the pin 32, and the hole portion 61b, which are a plurality of drive transmission portions provided on the same peripheral surface, are in uniform contact, and the pin 82, the groove portion 61a, the pin 32, and the hole portion 61b The drive transmission forces of are equal in magnitude. In this way, since the balance of the drive transmission force is maintained, no extra force other than the transmission of torque is generated, and therefore the driven unit is not vibrated due to the action of the extra force as in the prior art. It is prevented.

  By the way, in this Embodiment, although the phase of the groove part 61a and the hole part 61b of the coupling 61 is set to 90 degree | times, the reason is demonstrated below.

  3 and 4, attention is paid to the relative movement of the sleeve shaft 31 and the coupling 61, for example. As shown in the figure, the sleeve shaft 31 is swingable about the x-axis with respect to the coupling 61 and is also swingable about the y-axis, but there is a mechanical difference between the two swing operations. There is. That is, the swinging motion of the sleeve shaft 31 shown in FIG. 3 involves relative movement between the pin 32 and the hole 61b, whereas the swinging motion shown in FIG. 4 does not involve these relative movements. The former sliding motion is an axial sliding motion, while the latter sliding motion is a rotational motion. For this reason, the former has a larger sliding resistance (friction resistance) than the latter.

  When the coupling 61 and the sleeve shaft 31 are rotated in a state where there is an axial deviation, the states shown in FIGS. 3 and 4 appear alternately, and therefore, a variation in sliding resistance (friction resistance) with time occurs.

  The configuration shown in FIGS. 6 and 7 (cross-sectional view taken along the line C-C in FIG. 6) is obtained by aligning the phases of the groove 61a and the hole 61b for comparison with the configuration shown in FIGS. In the state shown in FIG. 6, the sliding resistance (friction resistance) of the sleeve shaft 31 and the drive shaft 81 is both small, and in the state shown in FIG. 7, both sliding resistance (friction resistance) is large. In the configuration shown in FIG. 6 and FIG. 7, the time variation of the sliding resistance (friction resistance) due to the rotation is the same phase on the sleeve shaft 31 side and the drive shaft 81 side. This is about twice as large as the fluctuation range. Thus, if the fluctuation range of the sliding resistance (friction resistance) is large, it may cause fluctuations in the rotational load, and if there is a load fluctuation, the rotation unevenness of the driven shaft and vibration in the drive section upstream of the drive shaft will occur. This is not preferable because it is a cause of generation (in an image forming apparatus, there is a concern that density unevenness may occur due to rotation unevenness).

  On the other hand, in the configuration according to the present embodiment shown in FIGS. 3 and 4, since the phases of the groove 61a and the hole 61b are orthogonal, the temporal variation of the sliding resistance (friction resistance) during rotation is The phase is shifted by 90 degrees between the sleeve shaft 31 side and the drive shaft 81 side. For this reason, when one of the sliding resistances is large, the state in which the other sliding resistance is small is repeated alternately. Therefore, the sum of the two is small, and the fluctuation of the rotational load is suppressed.

  As described above, by setting the phase of the groove 61a and the hole 61b of the coupling 61 to 90 degrees, it is possible to suppress the occurrence of rotational load fluctuations and prevent problems such as uneven rotation. can get.

  Next, an engagement operation between the coupling 61 and the drive shaft 81 when the process cartridge 21 is inserted into the apparatus main body will be described.

  In the state of the coupling 61 before the process cartridge 21 is mounted, the tip portion hangs down due to gravity as shown in FIG. The phase between the pin 82 of the drive shaft 81 and the groove 61a of the coupling 61 is in an arbitrary state.

  FIG. 8 shows a state where the phase of the pin 82 and the groove 61a is 90 degrees. As shown in FIG. 8, in order to match the phases from the state in which the pin 82 of the drive shaft 81 and the groove 61a of the coupling 61 are out of phase, the coupling 61 has tapered surfaces 61e, 61f, 61g, 61h is provided. One of the drive shaft 81 and the sleeve shaft 31 is rotated by pushing the process cartridge 21 in a state where the tapered surfaces 61e, 61f, 61g, 61h and the pin 82 of the drive shaft 81 are in contact with each other. And the groove 61a are in phase with each other to complete the engagement.

  In this configuration, since the gear input electromagnetic clutch 83 (see FIG. 15) is used, the idling load of the drive shaft 81 is about 50 to 100 gf-cm. On the other hand, since the load of the developing sleeve 13a and the injection sleeve 14a is about 700 to 2000 gf-cm, the drive shaft 81 side with a light load rotates. Since the taper surfaces 61e, 61f, 61g, and 61h have a vertex at a position of 90 degrees with respect to the groove portion 61a, the rotation amount of this rotation operation is 90 degrees at the maximum.

  As shown in FIG. 8, since the tip of the coupling 61 hangs downward, if the heights of the apexes 61i and 61j of the tapered portion are set to be the same at the two locations, the pin 82 has an upper tapered surface 61e. , 61g, and the rotation operation of the rotary shaft 81 becomes impossible. In order to avoid this engaging operation failure, the heights of the apexes 61i and 61j of the tapered portions are shifted as shown in FIG. As a result, when the coupling 61 is inserted, first, one end of the pin 82 comes into contact with the tapered surface 61e, and the other end of the pin 82 overlaps the tapered surface 61h in a state where the rotational operation has advanced to some extent. Thus, the engagement failure is avoided.

  Next, collision avoidance between the tip of the coupling 61 and the front end surface of the drive shaft 81 will be described.

  As shown in FIG. 9, in the present embodiment, a step is provided inside the cylindrical portion 61 c of the coupling 61. A shape when no step is provided is indicated by a two-dot chain line. An intersection 61k ′ between the inner diameter D1 of the cylindrical portion 61c and the taper apex 61i is at a position lower than the uppermost position 81k of the front end surface 81a of the drive shaft 81. For this reason, the front end portion 61 i of the coupling 61 collides with the front end surface 81 a of the drive shaft 81 with the mounting operation of the process cartridge 21. In order to avoid this, a step is provided inside the cylinder 61c of the coupling 61 to increase the position of the tip 61k inside the cylinder portion 61c. Specifically, by setting the step to 1 mm, the height relationship with the tip 81k of the drive shaft 81 is reversed, and the engagement failure is avoided.

  In the present invention, axial play is provided between the pin 82 and the groove 61a and between the pin 32 and the hole 61b. However, the same effect can be obtained regardless of whether or not circumferential play is provided.

  As described above, in a configuration where there is no play in the circumferential direction, both the shaft and the coupling can perform relative swinging motion, thereby realizing a smooth rotational drive and preventing the occurrence of vibration. Can be removed. Even in a configuration where there is play in the circumferential direction, as a matter of course, the relative swinging motion of the shaft and the coupling is possible, and thus the same effect can be obtained.

  A specific shape and size of the configuration having play in the circumferential direction will be described with reference to FIG.

  As shown in FIG. 10, the groove 61 a that engages with the pin 82 of the drive shaft 81 has a U-shaped groove shape. The width B1 is set to 3 to 3.5 mm, for example, while the width b1 of the counterpart pin 82 is 2 mm, and sufficient play in the circumferential direction is provided between the pin 82 and the groove 61a. .

  11A and 11B show an example of the shape of the hole 61b that engages with the pin 32 of the sleeve shaft 31, and the hole 61b is formed in a circular or square shape. The width B2 of the hole 61b is set to 3 mm, for example, while the width b1 of the counterpart pin 32 is 2 mm, and sufficient play in the circumferential direction is provided between the pin 32 and the hole 61b. .

  By providing play in the circumferential direction, the sliding operation at the time of unit insertion / removal becomes smoother in the groove 61a on the drive shaft 81 side. Moreover, since the hole diameter is large in the hole 61b on the sleeve shaft 31 side, there is an effect that the assemblability of the pin 32 is improved.

  Next, a method for mounting pins on the shaft will be described.

  There are “press-fit” and “insert” in the pin mounting method. “Press-fit” is to press-fit a parallel pin or a spring pin into a hole provided on the shaft, and is suitable for the drive shaft 81 side in the configuration of the present embodiment. The sleeve shaft 31 side is not preferably press-fitted in consideration of removal of the coupling 61 and assembly.

  The “insertion” method will be described with reference to FIGS. FIG. 12B is a plan view of FIG.

  Whereas the diameter of the pin 32 is φ2 mm, the diameter of the hole 31p of the sleeve shaft 31 is set to be slightly larger, for example, φ2.1 mm. Then, after the coupling 61 is fitted into the sleeve shaft 31, the pin 32 is inserted into the hole 31 p of the sleeve shaft 31. Next, the pin stopper 66 is attached to the coupling 61, and the pin 32 is prevented from falling off by closing the hole 61 b of the coupling 61 with the pin stopper 66. The pin stopper 66 is locked by the patching claw 66a. By releasing the patching claw 66a, the pin stopper 66, the pin 32, and the coupling 61 can be sequentially removed.

  In the configuration described above, the coupling 61 is mounted on the sleeve shaft 31 side. However, even when the coupling 61 is mounted on the drive shaft 81 side, the same operation and effect can be obtained.

  In the above description, the process cartridge 21 includes the developing device 13, the injection charger 14, and the photosensitive drum 11. However, the configuration of the process cartridge to which the present invention is applicable is not limited to this. Absent. The present invention can be suitably applied to a process cartridge having a driven shaft.

  Next, a structure for fixing the drum cylinder 131 and the drum shaft 51 of the photosensitive drum 11 (11C, 11M, 11Y, 11K) will be described with reference to FIGS.

  FIG. 16 is an exploded perspective view showing a fixing structure of the drum cylinder and the drum shaft. FIG. 17 is a cross-sectional view showing a state where the drum cylinder and the drum shaft are fixed. FIG. 18 is a sectional view showing a state where the drum cylinder and the drum shaft in the same phase are separated. 19 is a cross-sectional view taken along the line HH of FIG. 18, FIG. 20 is a side view of the drum cylinder and the drum shaft, and FIG. 21 is a plan view of the drum cylinder and the drum shaft.

  In FIG. 16, reference numeral 131 denotes a drum cylinder, and a drum flange 132 is press-fitted into an end portion thereof. Reference numeral 51 denotes a drum shaft. Pins 134 are press-fitted into the drum shaft 51, and both ends of the pins 134 protrude from the outer peripheral surface of the drum shaft 51 by a predetermined amount.

  The drum flange 132 is formed with two groove portions 135 in which the pins 134 play together, and the terminal portion of the groove portion 135 constitutes a V-shaped taper portion 136 as shown in FIGS. . The taper portion 136 is pressed against the pin 134 of the drum shaft 51 by an urging means described later, whereby the drum flange 132 is constrained to the drum shaft 51 without play.

  Here, the biasing means of the drum cylinder 131 will be described.

  Two protrusions 137 project from the opposing inner peripheral surface of the drum flange 132, and the drum shaft 51 is formed with two slits 138 in which the protrusions 137 loosely engage with each other. .

  In FIG. 16, reference numeral 139 denotes a knob, and a screw portion 139a is formed at the tip of the knob. The screw portion 139a is screwed to a female screw 133a machined inside the drum shaft 51. A guide member 140 is rotatably supported on the knob 139. The outer diameter of the guide member 140 is set to be slightly smaller than the inner diameter of the drum shaft 51. The guide member 140 is provided with protrusions 140 a at two locations, and the protrusions 140 a engage with the slot 138 formed on the drum shaft 51. The outer diameter of the protrusion 140 a of the guide member 140 is set to a value at which the protrusion 140 a does not protrude from the outer peripheral surface of the drum shaft 51.

  When the direction of the projection 137 of the drum flange 132 and the direction of the slot 138 of the drum shaft 51 coincide with each other, the drum flange 132 is inserted into the drum shaft 51 and the V-groove tapered portion 136 is press-fitted into the drum shaft 51. It is inserted until it hits 134.

  Next, the guide member 140 is passed through the knob 139, and the screw portion 139 a of the knob 139 is fastened to the female screw 133 a of the drum shaft 51. At this time, the direction of the protrusion 140a of the guide member 140 and the direction of the slot 138 of the drum shaft 51 are matched in advance.

  Thus, the rotation direction of the guide member 140 is regulated by the slot 138 of the drum shaft 51, but the guide member 140 and the knob 139 are rotatable, so that the operation for fastening the knob 139 to the drum shaft 51 is hindered. Absent. When the knob 139 is fastened to the drum shaft 51, the guide member 140 sequentially moves to the back side of the drum shaft 51, and finally the protrusion 140a of the guide member 140 and the protrusion 137 of the drum flange 132 abut. . The drum flange 132 is pressed against the drum shaft 51 in the axial direction.

  Next, a mechanism for adjusting the phase of the drum flange 132 and the drum shaft 51 in the rotational direction will be described.

  As shown in FIGS. 18 and 19, the leading end portion of the drum flange 132 forms a lead cam-like tapered portion 141. When the drum flange 132 is inserted into the drum shaft 51, the pin 134 protruding from the drum shaft 51 contacts the cam-like taper portion 141 of the drum flange 132, so that the drum flange 132 rotates. When the phase of the rotation direction of the pin 134 of the drum shaft 51 and the groove 135 of the drum flange 132 coincide and the pin 134 starts to be guided to the groove 135, the protrusion 137 of the drum flange 132 and the slot 138 of the drum shaft 51 are still Not engaged. Since the phases of the drum flange 132 and the drum shaft 51 already coincide with each other, when the drum flange 132 is further pushed in this state, the taper portion 136 of the drum flange 132 and the pin 134 of the drum shaft 51 come into contact with each other.

  After that, as described above, the knob 139 passing through the guide member 140 is fastened to the female screw 133a of the drum shaft 51, whereby the fixing of the drum flange 132 and the drum shaft 51 is completed.

  Thus, in this embodiment, since the force for pressing the drum flange 132 against the drum shaft 51 is transmitted by the guide member 140 within the cross section of the drum shaft 51, the drum shaft 51 is moved outside the drum flange 132. A normal bearing equal to the outer diameter of the drum shaft 51 can be used as the bearing 114 a of the centering plate 114 for positioning, and the drum cylinder 131 and the drum shaft 51 can be attached and detached from the outside of the centering plate 114. .

<Embodiment 2>
Next, a second embodiment of the present invention will be described with reference to FIGS. FIG. 22 is a cross-sectional view showing the configuration of the drive transmission unit of the drive transmission apparatus according to the present embodiment. In FIG. 22, the same elements as those shown in FIG. The description about them is omitted.

  In the configuration according to the present embodiment, couplings 62 and 63 are attached to the drive shaft 81 and the sleeve shaft 31, respectively.

  The coupling 62 is provided with a groove portion 62a and a claw portion 62b as parts for passing the drive. The groove portion 62a is engaged with the pin 82 of the drive shaft 81, and the claw portion 62b is a coupling on the sleeve side 31. It engages with the claw part 63b of 63 and delivers the drive.

  The coupling 62 includes a cylindrical portion 62c, and is supported with play (backlash) in the radial direction with respect to the outer diameter d1 of the drive shaft 81. As for the dimensions, the outer diameter d1 of the drive shaft 81 is φ8 mm, whereas the inner diameter D1 of the coupling 62 is φ8.5 mm.

  The coupling 62 is stopped with play by the pin 82 and the E-shaped retaining ring 84 with respect to the drive shaft 81, and the axial play δz1 between the pin 82 and the groove 62a is set to 0.5 mm.

  Similar to the first embodiment, by providing play in the radial direction and the axial direction, the coupling 62 and the drive shaft 81 are relatively swung around the two axes of the x axis perpendicular to the paper surface and the y axis in the vertical direction. It becomes movable. That is, the coupling 62 and the drive shaft 81 can swing around the intersection O1 between the axis of the pin 82 and the axis of the drive shaft 81 as a fulcrum.

  In the present embodiment, the width b1 of the pin 82 and the width B1 of the groove 62a are set to 2 mm and 3 mm, respectively, and a play in the circumferential direction is provided between the two, assembling as described in the first embodiment. Increases sex.

  On the other hand, like the coupling 62 on the drive shaft 81 side, the coupling 63 on the sleeve shaft 31 side is also mounted on the sleeve shaft 31 with play in the radial direction and the axial direction between the pin 32 and the groove portion 63a. The outer diameter d2 of the sleeve shaft 31 is φ8 mm, whereas the inner diameter D2 of the cylindrical portion 63c of the coupling 63 is φ8.5 mm. Further, the axial play δz2 between the pin 32 and the groove 63a is set to 0.5 mm. As a result, similarly, the coupling 63 and the sleeve shaft 31 can swing around the intersection O2 between the axis of the pin 32 and the axis of the sleeve shaft 31 as a fulcrum.

  Thus, in the movement between the two couplings 62 and 63, the two couplings 62 and 63 are constrained and integrated by the engagement method of the couplings 62 and 63, and the two cups are not constrained. The axes of the rings 62 and 63 may move with a degree of freedom. The former case has the same motion configuration as that of the first embodiment (one coupling 61), and the latter case has a configuration in which the degree of freedom is increased by one.

  In any case, as in the first embodiment, the axis of the drive shaft 81 and the sleeve shaft 31 and the axis of the couplings 62 and 63 are the same under the condition that the drive shaft 81 and the sleeve shaft 31 are misaligned. It intersects at a site where the drive is transmitted (thrust position where the pin 32 and the groove 63a engage). For this reason, the drive transmission force of the several drive transmission part provided on the same surrounding surface becomes an equal magnitude | size. Accordingly, the balance of the drive transmission force is maintained, no extra force is generated except for transmitting torque, and the occurrence of vibration is prevented in advance.

  Next, the engaging operation of the couplings 62 and 63 accompanying the mounting of the process cartridge 21 will be described.

  The coupling 63 is configured to be slidable in the axial direction with respect to the sleeve shaft 31. The spring 33 is a compression spring, and biases the coupling 63 in the right direction when the coupling 63 moves to the left in FIG. In the normal position shown in FIG. 22, the spring 33 is in a free length state, and the spring 33 does not bias the coupling 63. Therefore, the play δz2 is not lost, and this play δz2 is ensured.

  FIG. 23 is a view in the direction of the arrow FF in FIG. 22, and two claw portions 63 b are formed on the end surface of the coupling 63 (FIG. 22 shows the coupling 63 in a cross section, Only one claw 63b is shown). The tip surface 63d of the claw portion 63b is a flat surface orthogonal to the axis, and the drive transmission surface 63e is a surface that exists in a plane passing through the axis.

  The reason why the front end surface 63d of the claw portion 63b is not sharpened with a flat surface is to avoid a poor engagement of the couplings 62 and 63 (a poor alignment of the claw portions 62b and 63b). That is, the correct arrangement of the claw portions 62b and 63b of the couplings 62 and 63 facing each other in the circumferential direction is correct, but if the tips of the claw portions 62b and 63b are sharp, they are alternated during engagement. It may not be. This occurs when the centers of the couplings 62 and 63 do not coincide with each other due to the axial deviation of the couplings 62 and 63 or the tip part hanging down.

  Although the engagement of the couplings 62 and 63 is avoided by making the claw portions 62b and 63b flat, there is a possibility that a frontal collision between the claw tip portion 63d and the claw tip portion 62d may occur. For this reason, one coupling 63 is configured to be retractable in the axial direction. The claw portions 62b and 63b are engaged with each other by the retracted coupling 63 being returned to the normal position by the action of the spring 33 when the drive shaft 81 rotates and enters a phase in which both engage. .

  The present invention can also be applied to a drive system in which relative rotation between the two axes is not recognized.

  In the first embodiment, the drive system in which the rotation operation is permitted has been described. However, even if the drive system in which the rotation operation is not permitted has one coupling, the member is configured to be slidable as described above. Can be implemented.

  By the way, this embodiment can obtain the effects described below by specifying the shape (phase) in the component.

  The phase relationship between the drive transmission surface 63e of the coupling 63 and the groove 63a is set to 45 degrees as shown in FIG. Further, the same parts are used for the couplings 62 and 63 so as to be shared.

  FIG. 24 is a view in the direction of the arrow FF in FIG. 22 and shows the coupling 63 and the sleeve shaft 31. As shown in FIG. 24, the pin 32 of the sleeve shaft 31 is positioned at an angle of 45 degrees counterclockwise with respect to the drive transmission surface 63e of the coupling 63.

  FIG. 25 is a view in the direction of the arrow GG in FIG. 22, and shows the two couplings 62 and 63 and the two pins 32 and 82 together. An arrow Q indicates the direction of rotation. The pin 82 of the drive shaft 81 is positioned at an angle of 45 degrees clockwise with respect to the drive transmission surfaces 63e, 62e of the two couplings 62, 63. Therefore, the phase of the pin 82 of the drive shaft 81 and the pin 32 of the sleeve shaft 31 is (45 degrees + 45 degrees) = 90 degrees (orthogonal).

  When the phases of the pin 32 and the pin 82 are 90 degrees (orthogonal), the mechanism described in the first embodiment suppresses the occurrence of rotational load fluctuations, thereby preventing the occurrence of problems such as rotational unevenness. The effect is obtained. Further, in the present embodiment, the sharing of parts and the above-described functional effects can be achieved at the same time.

It is a cross-sectional view (DD sectional view of FIG. 14) which shows the structure of the drive transmission part of the drive transmission apparatus which concerns on Embodiment 1 of this invention. It is the sectional view on the AA line of FIG. 1 (the EE sectional view of FIG. 14). It is a cross-sectional view which shows operation | movement of the drive transmission part of the drive transmission apparatus which concerns on Embodiment 1 of this invention. It is the BB sectional view taken on the line of FIG. It is sectional drawing which shows the state which the drive shaft and sleeve axis | shaft of the drive transmission apparatus which concern on Embodiment 1 of this invention have produced shaft center shift | offset | difference. It is a cross-sectional view for comparing the operation of the drive transmission unit of the drive transmission device according to the first embodiment of the present invention. It is CC sectional view taken on the line of FIG. It is explanatory drawing of the engagement operation | movement of the coupling and drive shaft of the drive transmission apparatus which concerns on Embodiment 1 of this invention. It is explanatory drawing of the engagement operation | movement of the coupling and drive shaft of the drive transmission apparatus which concerns on Embodiment 1 of this invention. It is a figure which shows another form of coupling of the drive transmission device which concerns on Embodiment 1 of this invention. It is a figure which shows another form of coupling of the drive transmission device which concerns on Embodiment 1 of this invention. It is a figure which shows the mounting method of the pin with respect to the axis | shaft of the drive transmission apparatus which concerns on Embodiment 1 of this invention. 1 is a cross-sectional view of an image forming apparatus (full-color copying machine) according to the present invention. FIG. 3 is a cross-sectional view of an image forming unit of the image forming apparatus according to the present invention. 2 is a cross-sectional plan view of an image forming unit and a drive system of the image forming apparatus according to the present invention. FIG. It is a disassembled perspective view which shows the fixing structure of a drum cylinder and a drum axis | shaft. It is sectional drawing which shows the state in which the drum cylinder and the drum axis | shaft are being fixed. It is sectional drawing which shows the state which the drum axis | shaft which has a drum cylinder and the same phase as this isolate | separated. It is the HH sectional view taken on the line of FIG. It is a side view of a drum cylinder and a drum shaft. It is a top view of a drum cylinder and a drum axis. It is a cross-sectional view which shows the structure of the drive transmission part of the drive transmission apparatus which concerns on Embodiment 2 of this invention. It is a figure of the arrow FF line direction of FIG. It is a figure of the arrow FF line direction of FIG. It is a figure of the arrow GG line direction of FIG.

Explanation of symbols

21 Process cartridge 31 Sleeve shaft (driven shaft)
32 pin (protrusion)
61 Coupling (drive transmission means)
61a Groove 61b Hole 62 Coupling (drive transmission means)
62a Groove 62b Claw 63 Coupling (drive transmission means)
63a Groove 63b Claw 81 Drive shaft 82 Pin (projection)

Claims (12)

A rotatable image bearing member and a rotating member having a rotation shaft for forming an image on the image bearing member are integrated, and an image forming unit that can be attached to and detached from the image forming device, and an image forming device. An image carrier shaft fitted to the image carrier, a drive shaft provided in an image forming apparatus for applying a driving force to the rotating member, and a drive connecting member for transmitting the driving force from the driving shaft to the rotating shaft In an image forming apparatus having
The position of the image forming unit with respect to the image forming apparatus is determined by fitting the image carrier shaft to the image carrier, and the drive connecting member has an axial direction and a shaft on one of the drive shaft and the rotation shaft. Are attached with a degree of freedom in the circumferential direction of the shaft and the radial direction of the shaft, and the other shaft engages with the cylindrical portion of the drive connecting member with a degree of freedom in the radial direction and the axial direction of the shaft. The image forming apparatus is characterized in that the portion protrudes toward the upstream side in the insertion direction of the other shaft . The image forming apparatus according to claim 1, wherein the drive connecting member is attached to the one shaft with a pin with each degree of freedom. The difference between the outer diameter of an inner diameter and said one shaft of cylindrical section one axis is inserted, the other axis is smaller than the difference between the outer diameter of the inner diameter and the other axis of the cylindrical portion to be inserted The image forming apparatus according to claim 2. The phase relationship between the position of the pin attached to the drive connecting member and the one shaft and the position of the pin when the pin attached to the other shaft is engaged with the drive connecting member is orthogonal. The image forming apparatus according to claim 1, wherein the relationship is a relationship.   The image forming apparatus according to claim 1, wherein the rotating member is a developing sleeve for forming a toner image.   5. The image forming apparatus according to claim 1, wherein the rotating member is an image carrier that is a sleeve of a charger. 6. A rotatable image carrier, a rotary member having a rotary shaft for forming an image on the image carrier, and a rotary member attached to the rotary shaft, and transmitting a driving force from the drive shaft of the image forming apparatus to the rotary shaft And an image forming apparatus configured to engage an image carrier shaft provided in the image forming apparatus with the image carrier and engage the drive shaft with the drive connecting member. In process cartridges that can be mounted on
The position of the image forming unit relative to the image forming apparatus is determined by fitting the image carrier shaft to the image carrier, and the drive shaft is engaged with the cylindrical portion of the drive connecting member with a degree of freedom in the radial direction and axial direction of the shaft. The drive connecting member is attached with a degree of freedom in the axial direction of the rotating shaft, the circumferential direction of the shaft, and the radial direction of the shaft, and a part of the tip of the cylindrical portion is in the insertion direction of the drive shaft. A process cartridge which protrudes toward the upstream side . 8. The process cartridge according to claim 7, wherein the drive connecting member is attached to the rotating shaft with pins with respective degrees of freedom. The difference between the inner diameter of the cylindrical portion into which the rotating shaft is inserted and the outer diameter of the rotating shaft is smaller than the difference between the inner diameter of the cylindrical portion into which the driving shaft is inserted and the outer diameter of the driving shaft. The process cartridge according to claim 8. The phase relationship between the position of the pin attached to the drive connecting member and the drive shaft and the position of the pin when the pin attached to the rotating shaft is engaged with the drive connecting member is orthogonal. 10. The process cartridge according to claim 7, wherein the process cartridge is characterized in that:   11. The process cartridge according to claim 7, wherein the rotating member is a developing sleeve for forming a toner image on an image carrier.   11. The process cartridge according to claim 7, wherein the rotating member is an image bearing member that is a sleeve of a charger. 11.

Images