JP2013083763A - Detachable unit and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve positional accuracy of the rotation center of a rotor while suppressing an increase in cost.SOLUTION: There is provided a detachable unit (U2) comprising: a bearing member (17) having a positioned member (14) positioned and supported by a unit body (11) attached to and detached from a body (U1) of an image forming apparatus, a rotor (PR) supported by the unit body (11), a contact part (34a) supported at an end part of the rotor (PR), a rotating shaft (1) supported by the body (U1) of the image forming apparatus and an outer ring (17a) fixedly supported to the positioned member (14); a holder which has a contacted part (22a) with which the contact part (34a) can come into contact and a biasing member (23) for biasing the contacted part (22a) to the contact part (34a) side, a holder (19) supported by the positioned member (14); and a holding part (16c) for holding a held part (34) of the rotor (PR) in a state before the unit body (U2) is mounted.

Description

  The present invention relates to a detachable unit and an image forming apparatus.

  In a conventional image forming apparatus, in order to cope with wear or failure over time, a configuration in which an internal component can be attached to and detached from the image forming apparatus main body as an attachable and detachable unit. Are known. As a technique for connecting a drive source provided on the main body side to a drive source provided in the detachable unit and being mounted, the techniques described in the following Patent Documents 1 and 2 are conventionally known.

  Japanese Patent Application Laid-Open No. 2000-162922 as Patent Document 1 discloses that when a process unit (2) having a photosensitive drum (222a) is attached to the copying machine main body (1), the rear side of the photosensitive drum (222a). The flange (4b) on the side is fitted and positioned on the guide member (61) at the rear of the rotary drive shaft (6) extending from the copier body (1), and the front flange (4a) of the photosensitive drum (222a) is positioned. 4a) describes a configuration in which positioning is performed by a lock member (16) screwed to the front end of the rotary drive shaft (6) passing through the flange (4a) and rotatably supported by the bearing (10c). ing.

In Japanese Patent Application Laid-Open No. 2001-117308 as Patent Document 2, in the photosensitive unit having the photosensitive drum (11), the pressure support portion (33) is axially disposed with respect to the front end portion of the photosensitive drum (11). The pressure support part (33) is urged forward by a spring (32) and the pressure support part (33) pushed by the spring (32) is supported by the ball bearing (25). A structure is described in which the photosensitive drum (11) is rotatably supported by the ball bearing (25) by contacting the inner ring from the rear side. Therefore, in the configuration described in Patent Document 2, the pressure support portion (33) is configured separately from the ball bearing (25), and the pressure support portion (33) is axially moved while the spring (32) is contracted. The photosensitive drum (11) is removable from the housing of the photosensitive unit.
In the configuration described in Patent Document 2, the front end of the drive shaft (41) penetrating the photosensitive drum (11) is screwed with the thumbscrew (34), and the thumbscrew (34) is the inner ring of the ball bearing (25). The rotation can be transmitted by contacting the front surface of the.

Japanese Unexamined Patent Publication No. 2000-162922 (“0038” to “0049”, FIGS. 2 and 3) JP 2001-117308 A (“0011” to “0021”, FIG. 2, FIG. 4, FIG. 5)

  This invention makes it a technical subject to improve the position accuracy of the rotation center of a rotary body, suppressing an increase in cost.

In order to solve the technical problem, the detachable unit of the invention according to claim 1 comprises:
A unit main body detachably supported on the main body of the image forming apparatus;
A positioned member supported in a state of being positioned on the unit body;
A rotating body supported by the unit body;
A contact portion provided on a held portion disposed at an axial end of the rotating body;
A rotating shaft that is supported by the main body of the image forming apparatus and that passes through the rotating body and transmits driving to the rotating body when the unit main body is mounted;
A bearing member having an outer ring fixedly supported by the member to be positioned, and an inner ring rotatably supported by the outer ring;
A contacted portion that is movably supported by the unit main body along the axial direction of the rotating shaft and that can be contacted by the contact portion, and a bias that biases the contacted portion toward the contact portion in the axial direction A holding tool supported by the positioned member;
A holding member for holding the held portion of the rotating body in a state before the unit main body is mounted on the main body of the image forming apparatus;
It is provided with.

The invention according to claim 2 is the detachable unit according to claim 1,
A positioned portion that is provided on the positioned member and in which the detachable unit is positioned with respect to the main body of the image forming apparatus;
The bearing member disposed at a position overlapping the positioned portion with respect to the axial direction of the rotation shaft;
It is provided with.

In order to solve the technical problem, an image forming apparatus according to claim 3 is provided.
A main body of an image forming apparatus, comprising: a unit housing portion in which the detachable unit is housed; a rotating shaft that is disposed in the unit housing portion and extends along a detaching direction of the detachable unit; and a positioning portion that positions the detachable unit. When,
A unit main body that is detachably supported by the main body of the image forming apparatus, and a positioning target that has a positioned portion that engages with a positioning member of the main body of the image forming apparatus, and is supported while being positioned by the unit main body. A member, a rotating body supported by the unit main body, a contact portion provided in a held portion disposed at an axial end of the rotating body, and a unit supported by the main body of the image forming apparatus and the unit A rotating shaft that passes through the rotating body and transmits drive to the rotating body when a main body is mounted; an outer ring that is fixedly supported by the positioned member; and an inner ring that is rotatably supported by the outer ring; A contact member that is movably supported by the unit main body along the axial direction of the rotating shaft and that can be contacted by the contact portion and the contacted portion on the contact portion side in the axial direction. With The rotating member in a state before the unit main body is mounted on the main body of the image forming apparatus. The detachable unit having a holding member for holding the held portion;
It is provided with.

According to the first and third aspects of the invention, it is possible to improve the positional accuracy of the rotation center of the rotating body while suppressing an increase in cost as compared with the case where the configuration of the present invention is not provided.
According to the second aspect of the present invention, it is possible to improve the positional accuracy of the rotation center of the rotating body as compared with the case where the bearing member is not disposed at a position overlapping the positioned portion.

FIG. 1 is a perspective view of the image forming apparatus according to the first exemplary embodiment. FIG. 2 is an explanatory diagram showing a state in which the opening / closing portion has moved to the open position in the image forming apparatus of FIG. FIG. 3 is a diagram illustrating the entire image forming apparatus according to the first exemplary embodiment. FIG. 4 is an enlarged view of a main part of the toner image forming apparatus portion of FIG. FIG. 5 is a partial cross-sectional view of the photoconductor portion of the image forming apparatus in a state where the process unit of Embodiment 1 is mounted. 6 is an explanatory view showing a state in which the process unit shown in FIG. 5 is detached from the image forming apparatus main body. FIG. 7 is an explanatory view showing a state in which the rotating body is removed from the process unit shown in FIG. FIG. 8 is an explanatory diagram of the conventional configuration and the configuration of the first embodiment, FIG. 8A is an explanatory diagram of the force that is applied during mounting in the conventional configuration, and FIG. 8B is a diagram of the force that is applied by the cleaning member in the conventional configuration. FIG. 8C is an explanatory diagram of a force acting at the time of mounting in the configuration of the first embodiment, and FIG. 8D is an explanatory diagram of a force acting by the cleaning member in the configuration of the first embodiment. FIG. 9 is a diagram for explaining the comparison between the conventional configuration and the configuration of the first embodiment. FIG. 9A is a diagram illustrating a state in which the front end plate is inclined in the configuration shown in FIG. 8A. FIG. It is explanatory drawing of the state which inclined. FIG. 10 is an explanatory diagram of the positioning mechanism of the second embodiment, and is an explanatory diagram corresponding to FIG. 5 of the first embodiment. FIG. 11 is an explanatory diagram of the positioning mechanism of the third embodiment, and is an explanatory diagram corresponding to FIG. 5 of the first embodiment. FIG. 12 is an explanatory diagram of the positioning mechanism of the fourth embodiment, and is an explanatory diagram corresponding to FIG. 5 of the first embodiment.

Next, specific examples of embodiments of the present invention (hereinafter referred to as examples) will be described with reference to the drawings, but the present invention is not limited to the following examples.
In order to facilitate understanding of the following description, in the drawings, the front-rear direction is the X-axis direction, the left-right direction is the Y-axis direction, the up-down direction is the Z-axis direction, and arrows X, -X, Y, -Y, The direction indicated by Z and -Z or the indicated side is defined as the front side, the rear side, the right side, the left side, the upper side, the lower side, or the front side, the rear side, the right side, the left side, the upper side, and the lower side, respectively.
In the figure, “•” in “○” means an arrow heading from the back of the page to the front, and “×” in “○” is the front of the page. It means an arrow pointing from the back to the back.
In the following description using the drawings, illustrations other than members necessary for the description are omitted as appropriate for easy understanding.

FIG. 1 is a perspective view of the image forming apparatus according to the first exemplary embodiment.
FIG. 2 is an explanatory diagram showing a state in which the opening / closing portion has moved to the open position in the image forming apparatus of FIG.
In FIG. 1, a printer U as an example of an image forming apparatus according to the first exemplary embodiment is an example of an image forming apparatus main body, and includes a printer main body U1 as an example of a mounted apparatus. A first discharge tray TRh, which is an example of a first medium discharge unit, a so-called face-down tray TRh is provided on the upper surface of the printer body U1. On the front end side in the medium discharge direction of the first discharge tray TRh, an operation unit UI for input operation by a user is provided at the front portion of the upper surface, and a display unit or the like is provided in the operation unit UI. Yes. A front panel Ua as an example of an opening / closing portion is disposed on the upper front surface of the printer U, and a lower end portion of the front panel Ua is rotatably supported by the printer U body by a rotation shaft extending in the left-right direction. In FIG. 2, the printer main body U1 is formed with a process unit housing portion U1a and a toner cartridge housing portion U1b as an example of a unit housing portion, and the front panel Ua is shown in FIG. 2 from the closed position shown in FIG. When moved to the open position, the toner cartridge TC as an example of the developer container and the process unit U2 as an example of the detachable body unit can be exchanged.

FIG. 3 is a diagram illustrating the entire image forming apparatus according to the first exemplary embodiment.
In FIG. 3, a host computer HC is electrically connected to the printer U as an example of an image information transmitting apparatus, and electrical signals such as image information and control signals transmitted from the host computer HC are controlled by the printer U. Is input to the controller C as an example of the unit. The controller C temporarily stores input image information, converts the image information into information for forming a latent image at a preset time, and a laser driving circuit DL as an example of a latent image forming circuit. Output to.
The laser drive circuit DL outputs a drive signal to the latent image forming device ROS according to the input information. The operation of the operation unit UI, laser drive circuit DL, power supply circuit E for applying a voltage to a developing roll Ga and a transfer roll Rt, which will be described later, is controlled by a controller C.

FIG. 4 is an enlarged view of a main part of the toner image forming apparatus portion of FIG.
3 and 4, a toner image forming apparatus U2 as an example of a visible image forming apparatus that forms a black toner image is disposed on the left side of the latent image forming apparatus ROS. A laser beam L as an example of latent image forming light emitted from the latent image forming device ROS is incident on the rotating photoconductor PR.
3 and 4, the toner image forming apparatus U2 according to the first exemplary embodiment is an example of a rotating body, and includes a photoconductor PR that rotates in the direction of an arrow about a rotation axis PRa as an example of an image holding body. Around the photoconductor PR, along the rotation direction of the photoconductor PR, a charging roll CR as an example of a charging member, a developing device G, and a photoconductor cleaner CL as an example of an image carrier cleaning device. And are arranged. Further, the toner image forming apparatus U2 is unitized, and is configured to be detachable from the printer main body U1 as the process unit 2. In FIG. 2, the process unit U2 is attached and detached with the front cover Ua supported on the front surface of the printer body U1 so as to be opened and closed.

3 and 4, the surface of the photoreceptor PR is charged by a charging roll CR to which a charging voltage is applied, and then exposed and scanned by a laser beam L of a latent image forming apparatus ROS at a latent image writing position Q1. As a result, an electrostatic latent image is formed. The surface of the photoconductor PR on which the electrostatic latent image is formed rotates and moves sequentially through the development area Q2 and the transfer area Q3.
The developing device G includes a developing container V that accommodates toner as an example of a developer. In the developing container V, a developing roll Ga as an example of a developer holder that is opposed to the photoconductor PR in the developing region Q2 and to which a developing voltage is applied is rotatably supported. In the developing container V, toner agitating members Gb and Gc for conveying the toner while being agitated to the developing roll Ga are rotatably supported. Accordingly, the toner held on the surface is transported to the developing area Q2 as the developing roll Ga rotates, and the electrostatic latent image on the photoconductor PR passing through the developing area Q2 becomes a toner image as an example of a visible image. Developed.

One end of a supply path of a cartridge toner supply device TH1 as an example of a developer supply device fixedly supported by the printer U is connected to the front end portion of the developing container V. The other end of the supply path of the cartridge toner supply device TH1 is connected to a discharge port TC3 of a toner cartridge TC as an example of a developer container.
In FIG. 3, the toner cartridge TC has a cartridge main body TC1 as an example of a container main body that accommodates toner therein, and a toner conveying member TC2 as an example of an in-container conveying member is rotatable in the cartridge main body TC1. It is supported by. Therefore, according to the consumption of toner in the developing device G, the toner conveying member TC2 is driven to rotate, and the toner in the cartridge body TC1 is conveyed to the discharge port TC3. The toner discharged from the discharge port TC3 is transported to the developing container V of the developing device G by a replenishing transport member (not shown) in the replenishment path of the cartridge toner replenishing device TH1.

The toner cartridge TC is configured to be detachable by being inserted into and removed from the printer U in the front-rear direction. As shown in FIG. 2, the toner cartridge TC is attached and detached with the front cover Ua supported to be openable and closable on the front surface of the printer body U1 opened.
The photoconductor PR, the charging roll CR, the electrostatic latent image forming device ROS, the developing device G, and the like constitute a toner image forming device U2 that forms a toner image on the photoconductor PR.

1 and 3, a plurality of paper feed trays TR <b> 1 to TR <b> 4 as an example of a medium storage unit are provided below the printer U. The plurality of paper feed trays TR1 to TR4 contain a recording sheet S as an example of a medium to be conveyed to the transfer area Q3.
In FIG. 3, rails RL <b> 1 and RL <b> 1 are disposed inside the lower portion of the printer U as examples of container guide members that movably support the left and right ends of the paper feed trays TR <b> 1 to TR <b> 4 that are put in and out. Accordingly, the paper feed trays TR1 to TR4 are supported by the pair of left and right rails RL1 and RL1 so as to be movable in the front-rear direction, and the paper feed trays TR1 to TR4 can enter and exit from the front surface of the printer U.

In FIG. 3, a paper feeding device K is disposed on the paper feeding side of each of the paper feeding trays TR1 to TR4. The sheet feeding device K includes a pick-up roll Rp as an example of a medium take-out member, and a separating roll Rs as an example of a separating member made up of a feed roll as an example of a medium transport member and a retard roll as an example of a medium separating member. Have
The recording sheets S taken out by the pickup roll Rp of the paper feeding device K are separated one by one by the separation roll Rs and fed to the main body conveyance path SH1. The fed sheet S is transported by a sheet transport roll Ra as an example of a plurality of transport members arranged in the main body transport path SH1. The sheet S conveyed by the sheet conveying roll Ra is conveyed to the transfer area Q3 by a registration roll Rr as an example of a timing adjusting member in accordance with the timing when the toner image on the surface of the photoreceptor PR moves to the transfer area Q3. .

Further, a manual feed tray TR0 as an example of a manual feed unit is mounted on the left side of the printer U. The sheet S fed from the manual feed tray TR0 passes through the manual feed transport path SH2 from the manual feed additional transport path SH5, and is transported by the sheet transport roll Ra in the main body transport path SH1, and is supplied to the registration roll Rr. Is transferred to the transfer area Q3.
In FIG. 3, a transfer roll Rt as an example of a transfer device to which a transfer voltage is applied is disposed in the transfer region Q3. The transfer roll Rt is in contact with the photoconductor PR at a preset pressure in the transfer region Q3, and transfers the toner image on the photoconductor PR to the sheet S passing through the transfer region Q3.

In FIG. 4, after the toner image on the surface of the photoconductor PR is transferred to the sheet S in the transfer region Q3, the photoconductor PR contacts the photoconductor PR as an example of a cleaning member of the photoconductor cleaner CL. Thus, the residual toner as an example of the residual developer attached to the surface is removed, collected, and cleaned. The residual toner removed by the cleaning blade CL1 is accommodated in a cleaner container CL2 as an example of a cleaning container. The developer in the cleaner container CL2 is transported forward by a recovery auger CL3 as an example of a recovery transport member, returned to the developer container V through a recovery path CL4 provided at the front end, and reused.
The photoconductor PR from which the residual toner adhering to the surface is collected by the photoconductor cleaner CL is charged again by the charging roll CR. In the first embodiment, the charging roll CR is provided with a temperature sensor SN1 that detects the temperature of the charging roll CR as an example of a temperature detection member.

The sheet S on which the unfixed toner image is transferred in the transfer area Q3 is conveyed to the fixing area Q4 of the fixing device F with the toner image being unfixed. The fixing device F includes a heating roll Fh as an example of a heating fixing member and a pressure roll Fp as an example of a pressure fixing member, and toner in a fixing region Q4 where the heating roll Fh and the pressure roll Fp are in contact with each other. The image is fixed by heating.
The toner image forming device U2, the transfer roll Rt, and the fixing device F constitute an image recording member U2 + Rt + F that records an image on the sheet S.
The sheet S on which the fixing toner image is formed is guided by a sheet guide as an example of a medium guide member and conveyed to a discharge roll R1 as an example of a discharge member. The sheet S is discharged from the sheet discharge port Ha, which is an example of a medium discharge port, to the first discharge tray TRh by the paper discharge roll R1.

Above the fixing device F in the printer U, a main body reversing path SH3 connected to the sheet discharge port Ha is provided. A sheet reversing device U3 as an example of a medium reversing device, which is an additional device, is mounted on the manual feed tray TR0. An optional inversion path SH4 as an example of an additional inversion path connected to the main body inversion path SH3 is formed in the sheet inversion device U3. Therefore, during duplex printing, the sheet S on which the toner image is fixed in the fixing area Q4 passes through the main body sheet reverse path SH3 and the optional reverse path SH4, is conveyed to the registration roll Rr, and is retransmitted to the transfer area Q3. Is done.
The main body inversion path SH3 and the option inversion path SH4 constitute an inversion path SH3 + SH4.

  Further, the sheet reversing device U3 is provided with an optional paper discharge tray TRh1, which is an example of an additional medium discharge portion that is discharged in a state where the image recording surface of the sheet S is the upper surface, so-called face-up tray TRh1. . An optional discharge path SH6 as an example of an additional discharge path is provided between the optional discharge tray TRh1 and the main body reversing path SH3, and the user designates discharge to the optional discharge tray TRh1. In this case, the sheet S passes through the option discharge path SH6 from the main body reversing path SH3 and is discharged to the option discharge tray TRh1.

(Explanation of photoconductor drive shaft and process unit)
FIG. 5 is a partial cross-sectional view of the photoconductor portion of the image forming apparatus in a state where the process unit of Embodiment 1 is mounted.
In FIG. 5, the printer main body U1 of the printer U according to the first embodiment supports a drive shaft 1 that extends along the front-rear direction as an example of an attaching / detaching direction in which the process unit U2 is attached / detached. . The drive shaft 1 is rotatably supported by a bearing B1 as an example of a bearing member whose rear end is supported by the printer main body U1, and the drive shaft 1 includes a motor as an example of a drive source (not shown). Drive is transmitted.

The drive shaft 1 is formed in a cylindrical shape extending in the front-rear direction, and a transmission pin 2 protruding outward in the radial direction is supported at the front end portion. Note that the length of the transmission pin 2 in the radial direction of the drive shaft 1 is set to be equal to or shorter than the inner diameter of a cylindrical rear contact sleeve 36 extending rearward from a photosensitive member flange 33 described later.
A cylindrical taper piece 3 is fixedly supported at the rear end portion of the drive shaft 1 as an example of a contact portion, and the outer surface of the front end portion of the taper piece 3 becomes smaller in diameter as it goes forward. A conical contact surface 3a is formed.

6 is an explanatory view showing a state in which the process unit shown in FIG. 5 is detached from the image forming apparatus main body.
FIG. 7 is an explanatory view showing a state in which the rotating body is removed from the process unit shown in FIG.
5 to 7, the process unit U2 includes a unit frame 11 as an example of a unit body. The unit frame 11 includes a disc-shaped frame front portion 12 disposed on the front side as an example of the main body front portion, and a disk-shaped frame rear portion 13 disposed on the rear side as an example of the rear portion of the main body. The front frame 12 and the rear frame 13 are formed with a front through-hole 12a and a rear through-hole 13a penetrating in the front-rear direction corresponding to the drive shaft 1.

Further, a plate-like bracket 14 extending in the vertical and horizontal directions is supported on the front surface of the frame front portion 12 as an example of a positioned member. A positioning hole 14a as an example of a positioned part is formed at the end of the bracket 14 of the first embodiment, and a positioning pin P1 as an example of a positioning part supported by the unit frame 11 passes through the positioning hole 14a. Thus, the bracket 14 is supported in a state where the bracket 14 is positioned with respect to the unit frame 11.
A positioning hole 15 as an example of a positioned portion is formed in the outer end portion of the bracket 14, and when the process unit U2 is attached to the printer main body U1, a positioning portion provided in the printer main body U1. The positioning pins UP1 as an example are positioned by engaging two sets of the positioning holes 15. FIG. 5 shows only one set.
Further, a hooking claw 14b as an example of a fixed part is rotatably supported by the bracket 14, and is hooked on a hooking part UK as an example of a receiving part formed on the printer main body U1, thereby allowing the process to be performed. The unit U2 is fixed to the printer body U1, and the fixing is released by the rotation of the hooking claws 14b.

A cylindrical front sleeve 16 is fixedly supported on the inner peripheral surface of the front through-hole 12a as an example of a first bearing support portion.
The front sleeve 16 has a cylindrical front sleeve body 16a as an example of a support body. At the front end of the front sleeve body 16a, there is provided a fixed portion 16b that is formed in a disk shape extending radially outward and is fixedly supported by the bracket 14. An annular, donut-shaped retainer stopper 16c extending inward in the radial direction is formed at the rear end of the front sleeve 16a as an example of a holding stop portion and an example of a holding member of a rotating body.

A front bearing 17 as an example of a bearing member is supported on the inner peripheral surface of the front sleeve 16. The front bearing 17 is configured by a conventionally known ball bearing, a so-called ball bearing. As an example of the outer ring, an annular outer race 17a disposed outward in the circumferential direction, and an example of the inner ring in the circumferential direction. An annular inner race 17b arranged inward, and as an example of a rolling element, a ball 17c arranged between the outer race 17a and the inner race 17b and relatively rotatably supporting the outer race 17a and the inner race 17b Have The front bearing 17 according to the first embodiment is set so that the inner diameter of the inner race 17 b corresponds to the outer diameter of the drive shaft 1 and overlaps with the positioning hole 14 a with respect to the axial direction of the drive shaft 1. ing.
The front end surface of the outer race 17a is prevented from coming forward by a front bearing stopper 18 supported on the front surface of the fixed portion 16b as an example of a bearing stop member. Note that for the assembly, the outer periphery of the bearing 17 and the inner periphery of the sleeve 16 are usually required to have a backlash of several tens of microns. However, due to the backlash, the positioning accuracy of the photoconductor PR deteriorates. Therefore, it is desirable that the bearing 17 is press-fitted into the inner peripheral surface of the sleeve 16.

A cylindrical retainer 19 is supported between the front bearing 17 and the retainer stopper 16c as an example of a holder. The retainer 19 according to the first embodiment includes a disc-shaped retainer front portion 21 as an example of a first holding portion, and a disc-shaped retainer rear portion 22 as an example of a second holding portion. Between the retainer front part 21 and the retainer rear part 22, a spring 23 is attached as an example of an urging member to urge the parts 21 and 22 in a direction to separate them from each other.
A contact convex portion 21 a that contacts the rear surface of the inner race 17 b of the front bearing 17 is formed as an example of a first holding contact portion on the inner peripheral portion of the front end of the retainer front portion 21.
The rear end surface of the retainer rear portion 22 has an outer peripheral portion that comes into contact with the front end surface of the retainer stopper 16c and is prevented from coming out backward, and an inner peripheral portion of the rear end surface has a flange as an example of a contacted portion. A contacted portion 22a is formed. Further, as an example of a misassembly prevention portion, a deviation prevention rib 22b and a misassembly prevention projection 22c of the spring 23 projecting toward the retainer front portion 21 are provided at the radial center portion of the front end surface of the retainer rear portion 22 of the first embodiment. Is formed. The retainer 19 does not need to be integrally formed, and may be aligned and assembled as described above when the independent parts are assembled in the state shown in FIG.

A rear sleeve 26, which is an example of a second bearing support member, is fixedly supported on the inner peripheral surface of the rear through-hole 13a. A rear bearing stopper 26 a that protrudes inward is formed on the inner peripheral surface of the rear sleeve 26 as an example of a bearing stop portion.
A rear bearing 27 as an example of a bearing member is supported on the front portion of the inner peripheral surface of the rear sleeve 26. The rear bearing 27 of the first embodiment is configured in the same manner as the front bearing 17, and includes an outer race 27a, an inner race 27b, and a ball 27c. The outer race 27a is fixedly supported on the inner peripheral surface of the rear sleeve 26, and is prevented from coming back backward by a bearing stopper 26a.

5 and 6, the photoconductor PR as an example of the rotating body of the first embodiment includes a cylindrical sleeve 31 as an example of the rotating body. Disc-shaped photoreceptor flanges 32 and 33 are supported at both front and rear ends of the sleeve 31 as an example of a shaft end member. A cylindrical front contact sleeve 34 that protrudes in the front-rear direction is formed at the center of the front photosensitive flange 32 as an example of a held portion and an example of a contact member. A retainer contact portion 34a that can contact the flange contact portion 22a is formed at the front end portion of the front contact sleeve 34 as an example of a contact portion. Further, a serration 34b as an example of a transmitted portion to which the drive pin 2 of the drive shaft 1 is engaged and the drive is transmitted is formed at the rear end portion of the front contact sleeve 34.
In the front contact sleeve 34 of the first embodiment, the inner diameter of the portion 34c corresponding to the inner periphery of the flange 32 is formed corresponding to the outer diameter of the drive shaft 1, and the inner diameter of the retainer contact portion 34a and the serration 34b portions. Is formed larger in diameter than the outer diameter of the drive shaft 1. Therefore, the small diameter portion 34c corresponding to the inner periphery of the flange 32 is close to the drive shaft 1, and the retainer contact portion 34a and the serration 34b are separated from the drive shaft 1.

A cylindrical rear contact sleeve 36 extending rearward is formed as an example of a contact member at the center of the rear photosensitive flange 33. The outer peripheral surface of the rear end portion of the rear contact sleeve 36 is supported on the inner peripheral surface of the inner race 27b of the rear bearing 27 so as to be rotatable and movable in the axial direction.
On the inner periphery of the rear end surface of the rear contact sleeve 36, a contacted portion 36a with which the taper piece 3 contacts is formed.

Therefore, in the photoconductor PR of Example 1, the retainer contact portion 34a of the front photoconductor flange 32 contacts the flange contact portion 22a, and the inner race 17b of the front bearing 17 rotates integrally by the biasing force of the spring 23. To do. In other words, the front end portion of the photoconductor PR is rotatably supported by the front bearing 17 via the retainer 19. Further, the rear photoreceptor flange 33 is rotatably supported by the rear bearing 27 via the rear contact sleeve 36.
In the first embodiment, the front photoreceptor flange 32 is supported so as to be movable in the axial direction by the approach and separation between the retainer front portion 21 and the retainer rear portion 22, and the rear contact sleeve of the rear photoreceptor flange 33. 36 is supported by the inner race 27b of the rear bearing 27 so as to be movable in the axial direction. Therefore, the photoconductor PR is supported so as to be movable in the front-rear direction with respect to the unit frame 11.

(Operation of Example 1)
In the printer U according to the first embodiment having the above-described configuration, when the image forming operation is started, the drive shaft 1 is rotated, the photosensitive member PR is rotated from the transmission pin 2 via the serration 34b, and a latent image is formed. Development, transfer, and fixing are performed, and an image is formed on the recording sheet S.
When a part of the process unit U2 wears or breaks with time as the printer U is used, the front panel Ua is opened and the process unit U2 is replaced.

5 and 6, the photosensitive member PR of the first embodiment has flanges 32 and 33 rotatably supported by front and rear bearings 17 and 27 with respect to the unit frame 11. The position of is determined.
Therefore, as shown in FIG. 5, in the state where the process unit U2 is mounted on the printer main body U1, the drive shaft 1 is inserted into the flanges 32 and 33, and the taper piece 3 moves the contacted portion 36a of the rear flange 33 forward. And the front contact sleeve 34 is pushed forward via the sleeve 31 to elastically deform the spring 23 of the retainer 19. Accordingly, the rear flange 33 is abutted against the taper piece 3 by being urged by the spring 23, and the position of the photoconductor PR in the front-rear direction is determined.

Here, in the conventional configurations as shown in Patent Documents 1 and 2, the front end of the shaft and the unit itself are fixed with screws, and a screwdriver step is required for attaching and detaching the unit, and the attaching and detaching work is troublesome. There's a problem. Further, in this conventional configuration, if the operator's screw tightening is incomplete, there may be a problem that the rotation center of the photosensitive member is shifted or the rotation is shaken.
In particular, in the configuration described in Patent Document 2, the pressure support portion (33), the spring (32), and the ball bearing (25) are configured separately, and when the photosensitive drum (11) is assembled, the spring ( 32) It is necessary to work while shrinking, the assembly work is troublesome, and there is a high possibility of damaging the photoconductor, so it is necessary to pay close attention to the work or to prepare a separate jig. There is a problem that is difficult to reduce.

On the other hand, in the first embodiment, the positioning mechanism 14 to 19 including the bracket 14, the front sleeve 16, the front bearing 17, the front bearing stopper 18, and the retainer 19 are integrally configured. ˜19 can be easily attached to and detached from the unit frame 11, and the manufacturing cost can be easily reduced. In addition, the assembling work is facilitated, and problems such as the surface of the photoconductor PR contacting other members at the time of assembling to be scratched or broken are easily reduced, and the cost for replacement when broken is also reduced.
In the positioning mechanisms 14 to 19 of the first embodiment, the printer main body U1 penetrating the photoconductor PR is engaged with the drive shaft 1 and the action of the hooking claw 14b positions and fixes the printer main body U2 and the process unit U2. Therefore, work such as screwing is unnecessary. Therefore, in Example 1, the attaching / detaching operation of the unit U2 is very easy as compared with the techniques described in Patent Documents 1 and 2.

FIG. 8 is an explanatory diagram of the conventional configuration and the configuration of the first embodiment, FIG. 8A is an explanatory diagram of the force that is applied during mounting in the conventional configuration, and FIG. 8B is a diagram of the force that is applied by the cleaning member in the conventional configuration. FIG. 8C is an explanatory diagram of a force acting at the time of mounting in the configuration of the first embodiment, and FIG. 8D is an explanatory diagram of a force acting by the cleaning member in the configuration of the first embodiment.
Instead of the techniques described in Patent Documents 1 and 2, a structure in which the detachable unit and the rotating shaft are connected without using screws or the like, and the photosensitive member 01 is rotatably supported as shown in FIGS. 8A and 8B. The outer ring 02a of the bearing 02 to be moved is supported so as to be movable in the axial direction, and the photoconductor 01 is pressed against the taper piece 06a of the drive shaft 06 by the retainer 04 that urges the bearing 02 rearward by the spring 03. A configuration is possible in which drive is transmitted while performing (for example, Japanese Patent Application No. 2010-252367).

  In the configuration shown in FIG. 8A, the axially movable bearing 02 is urged by a spring 03. When the unit 07 is mounted, the front end plate 07a of the unit 07 is fixed to the printer main body 08 by a hooking claw 07b or the like. When so-called locked, the bearing 02 receives an axial reaction force from the taper piece 06a to be positioned according to the law of action and reaction. Therefore, the front end plate 07a of the unit 07 attached to the housing 09 is tilted by receiving the force F1 that the housing 09 bends due to the elastic force of the spring 03 and the reaction force.

FIG. 9 is a diagram for explaining the comparison between the conventional configuration and the configuration of the first embodiment. FIG. 9A is a diagram illustrating a state in which the front end plate is inclined in the configuration shown in FIG. 8A. FIG. It is explanatory drawing of the state which inclined.
In FIG. 9, members other than the front end plate, brackets, and bearings necessary for explanation are not shown.
In FIG. 9, when the front end plate 07a is tilted, the sleeve 010 fixed to the front end plate 07a is tilted, and a deviation of the center position 02a corresponding to the tilt of the bearing 02 built in the sleeve 010 is generated. The photoreceptor 01 supported by the bearing 02 is displaced from the predetermined rotation center position 01a by the amount of the deviation of the center position 02a. When the inclination angle of the front end plate 07a is the same, the shift amount of the rotation center position 01a increases as the distance L01 from the front end plate 07a to the bearing 02 increases in the axial direction.
The photoconductor 01 must be positioned with high accuracy in the printer body 08 for image formation. In particular, the positional relationship with the developing roll is important, and there is a possibility that problems such as density unevenness occur in a printed image with a deviation of several tens of microns.

Further, as shown in FIG. 8B, when the cleaning blade 011 that contacts the photoconductor 01 with a preset pressure is disposed, the contact pressure of the cleaning blade 011 is perpendicular to the axial direction. Acts on direction. Therefore, when the central portion in the axial direction of the photoconductor 01 is pushed by the contact pressure, a bending moment M1 is generated at the axial end portion, and the bearing 02 is connected to the drive shaft 06 as in the case shown in FIG. 8A. There is a risk of tilting with respect to the rotation center 06b. Further, since the bearing 02 supports the sleeve portion 014 of the photoconductor flange 012 that extends farther forward than the support portion 013 of the photoconductor flange 012 with respect to the drive shaft 01, the deflection of the photoconductor flange 012 cannot be ignored.
Therefore, in the configuration shown in FIGS. 8A and 8B, measures such as improving the accuracy of each component and improving the rigidity so that the rotation center of the bearing 02 is not inclined with respect to the rotation center 06b of the drive shaft 06 can be taken. There is a problem that it becomes necessary and costs increase.
In particular, as shown in FIGS. 8A and 8B, in a configuration in which the position of the bearing 02 is shifted back and forth in the axial direction with respect to the front end plate 07a, when a force perpendicular to the axial direction acts on the bearing 02, There is also a problem that the front end plate 07a cannot receive and the deflection tends to increase.

On the other hand, in the first embodiment, as shown in FIG. 8C, the front bearing 17 is fixedly supported so as to be located in the cross section of the bracket 14 via the front sleeve 16. On the other hand, the distance L01 between the front bearing 17 and the bracket 14 is almost zero. Therefore, compared to the case shown in FIG. 8A, even if the frame 11 of the unit is bent by the reaction force of the spring 23 and the bracket 14 is inclined as shown in FIG. 9B, the amount of deviation of the center position 17d of the front bearing 17 Is small, is hardly affected, can reduce the deviation of the central axis, and can maintain and improve accuracy. Therefore, the interval between the photosensitive member PR and the developing roll Ga is easily maintained at a predetermined interval, the deterioration in image quality is reduced over a long period of time, and the photosensitive member PR can be damaged when the unit U2 is transported. Is reduced.
Moreover, in Example 1, the front bearing 17 is arrange | positioned in the position which overlaps with the bracket 14 with respect to an axial direction. Therefore, as shown in FIG. 8D, when the photoconductor PR is pressed by the contact pressure of the cleaning blade CL1 or the like, the small diameter portion 34c comes into contact with the drive shaft 1, but the drive shaft 1 has sufficient rigidity and the press The applied force acts on the front bearing 17 and the rear bearing 27 on which the drive shaft 1 is supported. Therefore, even if a force is applied to the front bearing 17 by the contact pressure of the cleaning blade CL1 or the like, the bracket 14 that is disposed at an overlapping position in the axial direction and extends in the direction in which the force acts can be received. Compared to the configuration shown in FIG. 8B, the variation in the position of the front bearing 17 is easily reduced, and the accuracy is easily maintained and improved.

Further, in the first embodiment, the drive shaft 1 supports the front end portion of the photoreceptor PR, penetrates to the front of the front bearing 17 and is supported by the front bearing 17, and the process unit U2 is mounted. In this state, the drive shaft 1 itself functions as a strength member of the attached process unit U2. Therefore, sufficient rigidity can be ensured as a whole even if the rigidity of the process unit U2 itself is not increased so much, so that the image quality can be easily improved and the change with time can be reduced.
In the first embodiment, the front sleeve 16 is provided with a retainer stopper 16c. In a state before the photosensitive member PR shown in FIG. 7 is attached, the retainer stopper 16c contacts the retainer rear portion 22 pushed by the spring 23 to prevent the retainer stopper 16c from coming off. In addition, the front end of the photoconductor PR is held with the front contact sleeve 34 penetrating in a state before the photoconductor PR shown in FIG. Therefore, even when the process unit U2 is operated in a state before the process unit U2 is attached to the printer main body U1, the retainer stopper 16c contacts the front contact sleeve 34 even if the front end portion of the photosensitive member PR is shaken. Thus, the shake of the photoconductor PR is reduced, and the damage to the photoconductor PR and the shift of the central axis are reduced.

FIG. 10 is an explanatory diagram of the positioning mechanism of the second embodiment, and is an explanatory diagram corresponding to FIG. 5 of the first embodiment.
Next, a second embodiment of the present invention will be described. In the description of the second embodiment, components corresponding to those of the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. To do. The second embodiment is different from the first embodiment in the following points, but is configured in the same manner as the first embodiment in other points.
In FIG. 10, the positioning mechanisms 14 to 19 of the second embodiment have a retainer rear portion 22 ′ different from the retainer rear portion 22 of the first embodiment, and the inner peripheral end portion of the retainer rear portion 22 ′ has a flange contact recessed forward. A portion 22a ′ is formed, and the deviation prevention rib 22b of the spring 23 of the first embodiment also serves as an offset shape corresponding to the thickness of the flange contact portion 22a ′. The flange contact portion 22a ′ is configured to be able to be accommodated in a state in which the retainer contact portion 34a of the front contact sleeve 34 is fitted.

(Operation of Example 2)
In the positioning mechanisms 14 to 19 of the second embodiment having the above-described configuration, the flange contact portion 22a ′ is formed in a concave shape into which the retainer contact portion 34a is fitted, and the front contact sleeve 34 is displaced from the retainer rear portion 22 ′. It is possible to hold the photosensitive member PR more stably even when it is not attached to the process unit U2, and it is possible to improve the operability of the process unit U2 and simplify the packaging material. And

FIG. 11 is an explanatory diagram of the positioning mechanism of the third embodiment, and is an explanatory diagram corresponding to FIG. 5 of the first embodiment.
Next, a description will be given of a third embodiment of the present invention. In the description of the third embodiment, components corresponding to the components of the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. To do. The third embodiment is different from the first embodiment in the following points, but is configured in the same manner as the first embodiment in other points.
In FIG. 11, the positioning mechanisms 14 to 19 of the third embodiment have a retainer rear portion 22 ″ different from the retainer rear portion 22 of the first embodiment, and the retainer rear portion 22 ″ of the third embodiment has a spring as in the second embodiment. The deviation prevention rib 22b of the flange 23 also serves as an offset shape corresponding to the thickness of the flange contact portion 22a ″. The inner peripheral end of the retainer rear portion 22 ″ of the third embodiment has an outer diameter at the front end of the retainer contact portion 34a. A flange contact portion 22a ″ configured by a through-hole having a corresponding inner diameter is formed. Therefore, in the positioning mechanisms 14 to 19 of the third embodiment, the retainer contact portion 34a of the front contact sleeve 34 is the first and second embodiments. The outer peripheral surface is supported in a state of extending to the front in the axial direction as compared with 2 and penetrating through the flange contact portion 22a ″. Further, 21b "extended in a sleeve shape from the retainer front portion 21" provided with a guide shape 21a "for smooth intrusion of the rotary shaft 1 at the entrance portion of the hole through which the rotary shaft 1 passes is press-fitted into the front bearing 17. ing.

(Operation of Example 3)
In the positioning mechanisms 14 to 19 of the third embodiment having the above-described configuration, the connection and positioning of the flange contact portion 22a ″ and the retainer contact portion 34a are performed by fitting as in the second embodiment. The PR front contact sleeve 34 serves as a guide, and the retainer rear portion 22 ″ does not contact the drive shaft 1 alone, improving the guiding effect of the rotary shaft 1 of the retainer front portion 21 ″, and mounting the process unit U2 to the printer body U1. However, when the retainer front portion 21 ″ is employed, depending on the component accuracy of the retainer 21 ″, the rotational accuracy of the photoconductor PR, that is, the so-called shake may deteriorate, and the retainer rear portion 22 ″. You may adopt only.

FIG. 12 is an explanatory diagram of the positioning mechanism of the fourth embodiment, and is an explanatory diagram corresponding to FIG. 5 of the first embodiment.
Next, the fourth embodiment of the present invention will be described. In the description of the fourth embodiment, the same reference numerals are given to the components corresponding to the components of the first embodiment, and the detailed description thereof will be omitted. To do. The fourth embodiment is different from the first embodiment in the following points, but is configured in the same manner as the first embodiment in other points.
In FIG. 12, the positioning mechanisms 14 to 19 of the fourth embodiment have the retainer front portion 21 of the first embodiment omitted, and the spring 23 ′ is not in the same cylindrical shape along the axial direction. The outer diameter is reduced by a conical spring. The spring 23 'of the fourth embodiment has an outer diameter at the front end corresponding to the inner race 17b of the front bearing 17, and is supported in contact with the rear end surface of the inner race 17b.

(Operation of Example 4)
In the positioning mechanisms 14 to 19 of Example 4 having the above-described configuration, the retainer front portion 21 is omitted, the number of parts is reduced, and the manufacturing cost is further reduced.

(Example of change)
As mentioned above, although the Example of this invention was explained in full detail, this invention is not limited to the said Example, A various change is made in the range of the summary of this invention described in the claim. Is possible. Modification examples (H01) to (H02) of the present invention are exemplified below.
(H01) In each of the above-described embodiments, the printer U is illustrated as an example of the image forming apparatus. However, the present invention is not limited to this. Further, although a monochromatic, so-called monochrome image forming apparatus is illustrated, the present invention is not limited to this, and the present invention can be applied to a multicolor, so-called color image forming apparatus.

(H02) In each of the above embodiments, the position of the front bearing 17 is described on the premise that the front bearing 17 is disposed at a position overlapping with the flat bracket 14 with respect to the axial direction. Although it is preferable from the point, it is not limited to this, and even if the bracket shape has a surface shifted in the front-rear direction, if the engagement position of the apparatus main body positioning portion and the bracket 14 overlaps the cross-sectional area of the bearing 17, It is also possible to exhibit the effects of the invention.

1 ... rotating shaft,
11 ... Unit body,
14: Positioned member,
14a: Positioned part,
17 ... Bearing member,
17a ... outer ring,
17b ... Inner ring,
19 ... retainer,
22a, 22a ', 22a "... contacted part,
23, 23 'biasing member,
34a ... contact part,
P1 ... positioning part,
PR ... Rotating body,
U: Image forming apparatus,
U1 ... main body of the image forming apparatus,
U1a: Unit housing,
U2: Detachable unit.

Claims (3)

A unit main body detachably supported on the main body of the image forming apparatus;
A positioned member supported in a state of being positioned on the unit body;
A rotating body supported by the unit body;
A contact portion provided on a held portion disposed at an axial end of the rotating body;
A rotating shaft that is supported by the main body of the image forming apparatus and that passes through the rotating body and transmits driving to the rotating body when the unit main body is mounted;
A bearing member having an outer ring fixedly supported by the member to be positioned, and an inner ring rotatably supported by the outer ring;
A contacted portion that is movably supported by the unit main body along the axial direction of the rotating shaft and that can be contacted by the contact portion, and a bias that biases the contacted portion toward the contact portion in the axial direction A holding tool supported by the positioned member;
A holding member for holding the held portion of the rotating body in a state before the unit main body is mounted on the main body of the image forming apparatus;
A detachable unit characterized by comprising: A positioned portion that is provided on the positioned member and in which the detachable unit is positioned with respect to the main body of the image forming apparatus;
The bearing member disposed at a position overlapping the positioned portion with respect to the axial direction of the rotation shaft;
The detachable unit according to claim 1, further comprising: A main body of an image forming apparatus, comprising: a unit housing portion in which the detachable unit is housed; a rotating shaft that is disposed in the unit housing portion and extends along a detaching direction of the detachable unit; and a positioning portion that positions the detachable unit. When,
A unit main body that is detachably supported by the main body of the image forming apparatus, and a positioning target that has a positioned portion that engages with a positioning member of the main body of the image forming apparatus, and is supported while being positioned by the unit main body. A member, a rotating body supported by the unit main body, a contact portion provided in a held portion disposed at an axial end of the rotating body, and a unit supported by the main body of the image forming apparatus and the unit A rotating shaft that passes through the rotating body and transmits drive to the rotating body when a main body is mounted; an outer ring that is fixedly supported by the positioned member; and an inner ring that is rotatably supported by the outer ring; A contact member that is movably supported by the unit main body along the axial direction of the rotating shaft and that can be contacted by the contact portion and the contacted portion on the contact portion side in the axial direction. With The rotating member in a state before the unit main body is mounted on the main body of the image forming apparatus. The detachable unit having a holding member for holding the held portion;
An image forming apparatus comprising:

Images