JP2006284923A - Sealing mechanism and developer replenishing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a simply constituted sealing mechanism dispensing with the control of pressing pressure, and also, which is improved in recycling properties. <P>SOLUTION: The sealing mechanism comprises; an elastic seal ring 40 which is fitted to a rotating shaft 29, and where the diameter of an insertion hole 43 formed in the thin ring main body part 41 to which the rotating shaft 29 is inserted is set smaller than the outside diameter of the rotating shaft 29, and also, a thick annular fitting part 42 is formed on the outer peripheral part; and a bearing 30 equipped with an annular fitting groove 33 which is formed concentric to the shaft hole 32 where the rotating shaft 29 is inserted, into which the annular fitting part 42 is fitted, and whose groove width is set smaller than the thickness of the annular fitting part 42. The seal ring 40 is fixed to the bearing 30 by fitting the annular fitting part 42 to the annular fitting groove 33, and the outer periphery of the rotating shaft 29 slides on the part where the insertion hole 43 is formed, with the rotation of the rotating shaft 29, then, the developer is prevented from passing through the insertion hole 43. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a sealing mechanism for preventing powder from entering between a rotating shaft supported between opposing side walls of a container in which powder is accommodated and a bearing supporting the rotating shaft. And a developer replenishing device having such a sealing mechanism.

  In image forming apparatuses such as copiers, printers, and facsimiles that employ an electrophotographic system, an electrostatic latent image is formed on a photoreceptor, and then the electrostatic latent image is developed into a toner image.

  A developing device for developing an electrostatic latent image into a toner image includes a developing tank that contains a so-called one-component developer made of only toner or a so-called two-component developer made of toner and carrier particles. In the developing tank, a developing roller that conveys the developer contained therein to the developing area and supplies it to the photoreceptor, a conveying roller that conveys the developer to the developing roller, and a stirring roller that agitates the developer Etc. are arranged.

  Further, the developing device includes a toner replenishing device for replenishing toner to the developing tank. The toner replenishing device transports the toner in the replenishing tank toward the toner discharging port, a replenishing tank in which the toner is stored, a toner discharging port communicating with the developing tank and the developing tank formed on the bottom wall of the supplying tank. The replenishment roller etc. which are replenished are included.

  Each of the rotating members such as the replenishing roller, the conveying roller, and the agitating roller has a rotation shaft that is rotatably supported between opposing side walls of the replenishing tank or the developing tank. For example, in the case of a replenishing roller, a porous material such as a sponge is wound around the rotating shaft.

  One end of the rotating shaft of each rotating member protrudes outward from one side wall through a through-hole formed in one side wall of a container constituting a replenishing tank or a developing tank, and an input gear is mounted on the protruding end. Thus, the driving force is transmitted.

  For example, in the case of a replenishing roller, the toner replenishing device is mounted at a required position of the developing device, so that the driving force can be transmitted to the rotation shaft of the replenishing roller. As the rotary shaft is driven to rotate, the spiral blade and the discharge blade are also rotated, and the toner present in the container is discharged from the toner discharge port into the developing tank located below.

  By the way, in each rotating member such as such a replenishment roller, leakage of powder such as toner from between the rotating shaft and a through hole formed in one side wall, toner or the like on a shaft supporting portion that supports the rotating shaft, etc. In order to prevent the occurrence of rotation failure due to the intrusion of the powder, a sealing mechanism is provided.

  As this sealing mechanism, for example, in Patent Document 1, a V-ring (seal member) is press-fitted into the vicinity of one side wall of the developing tank located in the developing tank on the rotation shaft, and the tip of the V-ring is elastically deformed. The rotary shaft is pressed against a bearing holder or the like that supports the rotary shaft, and a seal layer made of a member having a hardness lower than that of the V ring is provided at the press contact portion. A configuration is disclosed in which the intrusion of powder such as toner is prevented by sliding and rubbing the leading end to form a ring-shaped groove.

  In Patent Document 2, a seal ring member is mounted between a circular flange formed in the vicinity of one side wall of the developing tank located in the developing tank on the rotating shaft and the side wall of the developing tank, and development on the rotating shaft is performed. A locked groove is formed at one end located outside the tank, and an input gear is attached to one end of the rotating shaft, thereby providing an annular fitting portion of the input gear with the rotating shaft. Leakage of powder from between the rotary shaft and a through hole formed in one side wall by locking the locking projection in the locked groove and compressing (elastically deforming) the seal ring member in the axial direction. The structure which prevents this is disclosed.

In Patent Document 3, a non-woven ring made of a rubber elastic ring and a felt is integrally bonded by heat welding of a heat-meltable plastic adhesive film, and a bearing seal ring made of an elastic ring portion and a non-woven ring portion is provided. The ring is inserted into the stirring shaft base of the toner container, and the inner peripheral surface of the nonwoven fabric ring is in close contact with the peripheral surface of the rotating shaft, and the inner peripheral edge of the elastic ring is pushed out in the inserting direction of the rotating shaft. After mounting in a state where the dimensions are curled, the rotary shaft is inserted into the bearing hole, and the outer surface of the elastic ring portion of the seal ring is pressed against and fixed to the outer periphery of the bearing hole, so that the seal ring rotates when the rotary shaft rotates. First, the rotating shaft is frictionally rotated within the inner diameter hole of the seal ring, and the toner leakage from the friction rotating surface between the peripheral surface of the rotating shaft and the seal ring and the pressure contact surface around the outer periphery of the bearing hole is sealed. There has been disclosed.
JP 11-038758 A (published on February 12, 1999) JP 10-142936 A (published May 29, 1998) JP 2003-76145 A (published March 14, 2003)

  Certainly, in the above-described conventional configuration, the sealing performance is enhanced, the leakage of powder such as toner from between the rotation shaft and the through hole formed in one side wall, and the toner on the shaft support portion that supports the rotation shaft. It is possible to prevent the occurrence of rotation failure due to the intrusion of powder such as.

  However, in the above conventional configuration, it is necessary to manage the pressure for pressing the V ring and the pressure for compressing the seal ring member, and even if such pressure management is not necessary, the recyclability is poor. Have.

  In other words, in the configurations described in Patent Documents 1 and 2, the seal layer provided on the bearing holder has an elastic tip portion called a bellows by pressing the V ring or the seal ring member in the axial direction. It is a mechanism that creates a sealing function by pressing against a surface such as one side wall of a developing tank. Therefore, management of the pressing force is necessary.

  In Patent Document 1, in order to manage the pressure, it is necessary to appropriately set a separation distance between the V-ring press-fitted into the rotating shaft and the seal layer to which the tip of the V-ring is pressed. In Patent Document 2, it is necessary to appropriately set the separation distance between the circular flange and the side wall of the developing tank.

  On the other hand, in the configuration of Patent Document 3, since the axial pressing pressure is not used, such pressure management is not necessary. However, because a rubber seal ring and a nonwoven fabric ring are used as a bearing seal ring in which heat-meltable plastic adhesive film is integrally bonded by heat welding, the rubber elastic ring and the nonwoven fabric ring cannot be peeled off during recycling. is necessary. And since an adhesive film remains in a rubber elastic ring and / or a nonwoven fabric ring, the process etc. which remove an adhesive film are further needed, and it is inferior to recyclability.

  The present invention has been made in view of the above-described problems, has a simple structure that does not require management of pressing pressure, and is excellent in recyclability, and development provided with the same. The object is to provide an agent replenishing device.

  In order to solve the above-described problems, the sealing mechanism according to the present invention provides a powder between a rotary shaft supported between opposing side walls of a container in which powder is stored and a bearing that supports the rotary shaft. A sealing mechanism for preventing a body from entering, and a diameter of an insertion hole formed in a thin ring main body portion through which the rotation shaft is inserted and the rotation shaft is inserted is formed outside the rotation shaft. An elastic seal ring member that is set smaller than the diameter and has a thick annular fitting portion formed on the outer peripheral portion, a shaft hole through which the rotating shaft is inserted, and concentric with the shaft hole The annular fitting groove formed in the seal ring member is fitted, and the groove width of the annular fitting groove is larger than the thickness of the annular fitting part. A small bearing, and the seal ring member has the annular fitting portion described above. It is fixed to the bearing by being fitted in an annular fitting groove, and the outer periphery of the rotary shaft slides through the insertion hole forming portion in the seal ring member as the rotary shaft rotates. Yes.

  In the above configuration, the insertion hole forming portion in the thin ring main body portion of the seal ring member functions as a bellows, and the outer periphery of the rotating rotating shaft slides on the bellows, so that the inside of the seal ring member, that is, the bearing It is designed to prevent the powder from entering the side, and unlike the seal mechanism using the V-ring, it is not necessary to manage the axial pressure, and the configuration is simple.

  In addition, the seal ring member is fixed by fitting a thick annular fitting portion formed on the outer periphery of the ring main body portion into an annular fitting groove formed in the bearing. Since it is not a configuration to be used, it is excellent in recyclability because it is easy to disassemble at the time of recycling, and does not require a step of removing the adhesive.

  In the seal mechanism of the present invention, the groove width of the annular fitting groove of the bearing with respect to the thickness of the annular fitting portion of the seal ring member is caused by the rotation of the seal ring member accompanying the rotation of the rotary shaft. And the diameter of the insertion hole of the seal ring member when the tightening amount is given is set to be smaller than the diameter of the insertion hole of the seal ring member when the tightening amount is not given. It can also be configured.

  In the seal mechanism of the present invention, the seal ring member needs to be fixed to the bearing only by fitting the annular fitting portion of the seal ring member into the annular fitting groove provided in the bearing. Bearings against the diameter of the insertion hole of the seal ring member with respect to the outer diameter of the rotating shaft and the thickness of the annular fitting portion of the seal ring member so that the ring member does not rotate and the passage of the powder due to the eccentricity of the insertion hole does not occur By designing the groove width of the annular fitting groove, the sealing mechanism of the present invention can be easily realized.

  In the sealing mechanism of the present invention, the groove width of the annular fitting groove of the bearing with respect to the thickness of the annular fitting portion of the seal ring member is further increased when the rotary shaft is detached from the bearing. It can also be set as the structure set so that a ring member may not remove with a rotating shaft.

  With such a configuration, when the rotary shaft is detached from the bearing, such as during maintenance, the seal ring member does not come off together with the rotary shaft, and the maintenance performance is excellent.

  Further, in the sealing mechanism of the present invention, the annular fitting groove of the bearing further includes an annular standing portion erected on the inner periphery and the outer periphery, and the outer peripheral side from the annular standing portion on the inner periphery side. And the outer diameter of the roller having the rotating shaft is set to be larger than the outer diameter of the inner peripheral ring standing portion and smaller than the inner diameter of the outer peripheral ring standing portion. And the axial direction edge part of the said roller can also be set as the structure currently fitted by the inner side of the said cyclic | annular standing part of the said outer peripheral side.

  According to this, the insertion hole forming part which exhibits the sealing function in the seal ring member is shielded from the space part in the container by fitting the axial end of the roller inside the annular standing part on the outer peripheral side. As a result, the amount of powder pressed toward the seal ring member can be reduced, and the sealing performance can be improved.

  In order to solve the above problems, the developer replenishing device of the present invention includes a container containing a developer and a developer replenishing roller having a rotation shaft that is pivotally supported between opposing side walls of the container, A developer replenishing device for replenishing the developer in the container to the developer tank by the rotation of the developer replenishing roller, between a rotating shaft of the developer replenishing roller and a bearing that supports the rotating shaft. An insertion hole formed in a thin ring main body portion through which the rotary shaft is inserted and the seal mechanism is provided around the rotary shaft, and includes a seal mechanism for preventing powder from entering. And an elastic seal ring member having a thick annular fitting portion formed on the outer peripheral portion and a shaft hole through which the rotary shaft is inserted. The seal ring member is formed concentrically with the shaft hole. A bearing having an annular fitting groove into which the formed annular fitting portion is fitted, and the groove width of the annular fitting groove being set smaller than the wall thickness of the annular fitting portion. The seal ring member is fixed to the bearing by the annular fitting portion being fitted into the annular fitting groove of the bearing, and the outer periphery of the rotary shaft moves along the seal ring with the rotation of the rotary shaft. It is characterized by sliding through the insertion hole forming portion of the member.

  As already described, the seal mechanism of the present invention has a simple configuration that does not require management of the pressing pressure and is excellent in recyclability. By mounting as a sealing mechanism, it is possible to obtain a developer replenishing device that is simple in configuration and excellent in recyclability. Further, since the developer replenishing roller is intermittently driven only during the developer replenishing operation with respect to the developing roller and the stirring roller continuously driven during printing, such a simple sealing mechanism is also used. It is possible to withstand until the lifetime of the device body comes.

  As described above, in the sealing mechanism according to the present invention, the powder enters between the rotating shaft that is supported between the opposing side walls of the container in which the powder is stored and the bearing that supports the rotating shaft. This is a sealing mechanism for preventing this, and the diameter of the insertion hole formed in the thin ring main body portion through which the rotation shaft is inserted is larger than the outer diameter of the rotation shaft. The seal ring member is set to be small and has an elastic seal ring member with a thick annular fitting portion formed on the outer peripheral portion, and has a shaft hole through which the rotating shaft is inserted, and is formed concentrically with the shaft hole. The annular fitting groove formed in the seal ring member is fitted, and the groove width of the annular fitting groove is set smaller than the wall thickness of the annular fitting portion. The seal ring member has an annular fitting portion in which the annular fitting portion has an annular fitting. Is fixed to the bearing by being fitted into the groove, the outer periphery of the rotating shaft in accordance with rotation of the rotary shaft is characterized by sliding the insertion hole forming portion of the seal ring member.

  In the above configuration, unlike the seal mechanism using a V-ring, management of axial pressure is not necessary, and the configuration is simple. In addition, since the seal ring member is fixed without using an adhesive or the like, it is easy to disassemble at the time of recycling. ing.

  Therefore, there is an effect that it is possible to provide a sealing mechanism that has a simple configuration that does not require management of the pressing pressure and that is excellent in recyclability.

  As described above, the developer replenishing device of the present invention includes a container containing a developer and a developer replenishing roller having a rotation shaft that is pivotally supported between opposing side walls of the container. A developer replenishing device for replenishing the developer in the container to the developer tank by rotation of the replenishing roller, wherein powder is provided between a rotating shaft of the developer replenishing roller and a bearing supporting the rotating shaft. A sealing mechanism for preventing entry, and the sealing mechanism is mounted around the rotating shaft, and the diameter of the insertion hole formed in the thin ring body portion through which the rotating shaft is inserted is An elastic seal ring member which is set smaller than the outer diameter of the rotating shaft and has a thick annular fitting portion formed on the outer periphery thereof, and has a shaft hole through which the rotating shaft is inserted. Concentric with the hole, formed on the seal ring member A bearing having an annular fitting groove into which the annular fitting portion is fitted, and wherein the groove width of the annular fitting groove is set smaller than the thickness of the annular fitting portion. The ring member is fixed to the bearing by fitting the annular fitting portion into the annular fitting groove of the bearing, and the outer periphery of the rotating shaft is inserted into the seal ring member as the rotating shaft rotates. It is characterized by sliding in the hole forming part.

  As already described, the seal mechanism of the present invention has a simple configuration that does not require management of the pressing pressure and is excellent in recyclability. By mounting as a sealing mechanism, it is possible to provide a developer replenishing device that is simple in configuration and excellent in recyclability.

  An embodiment of the present invention will be described below with reference to FIGS.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In this embodiment, the seal mechanism according to the present invention is exemplified by a configuration adopted in a rotating member provided in a toner replenishing device (developer replenishing device) provided in the developing device of the image forming apparatus. explain.

  First, the operation of the entire image forming apparatus will be described with reference to the configuration diagram of FIG. Here, an analog image forming apparatus including an analog optical system is illustrated as the exposure optical system 2, but a digital image forming apparatus including a digital optical system including a CCD sensor may be used. Good. Further, as the developing device, a configuration in which a two-component developer composed of a carrier and toner is illustrated, but a one-component developer composed only of toner may be used.

  As shown in FIG. 2, in the image forming apparatus, a document placing table 1 is provided on the upper surface portion, and an exposure optical system 2 is disposed below the document placing table 1. The exposure optical system 2 includes a light source lamp 3 that scans a document (not shown) placed on the document placing table 1 while irradiating light, and a plurality of reflecting mirrors that guide reflected light from the document to the photosensitive member 4. 5 and the lens unit 6 arranged in the optical path of the reflected light.

  On the outer periphery of the photoreceptor 4, a charging charger 7 for charging the surface thereof to a predetermined potential, an interimage eraser (not shown), a developing device 8 for developing an electrostatic latent image formed on the surface of the photoreceptor 4, and a photosensitive member. A transfer charger 9 for transferring the toner image on the surface of the body 4 to a sheet (sheet), a cleaning device 10 for collecting residual toner on the surface of the photoconductor 4, a static eliminator (not shown), and the like are provided.

  A timing roller 11 for supplying paper at a predetermined timing, a transport roller 12, a paper feed cassette 13, and a paper feed roller 14 are provided on the paper input side with respect to the photoconductor 4, while on the paper output side with respect to the photoconductor 4. Is provided with a fixing device 15 for fixing the toner image transferred onto the paper to the paper.

  As shown in FIG. 3, the developing device 8 has a resin-molded developer tank 16 that constitutes a container for containing the developer. In the developer tank 16, the developer is transported and stirred. Agitating and conveying screws (rotating members) 18 and 19 for performing the above and a developing roller (rotating member) 17 for magnetically adsorbing and conveying the developer supplied by the agitating and conveying screw 18 are rotatably provided.

  As is well known, the developing roller 17 is configured to rotationally drive a cylindrical non-magnetic sleeve in the direction of the arrow so as to cover a magnet having a large number of magnetic poles provided on the peripheral surface. Therefore, the developer is attracted to the sleeve surface by the magnetic force of the magnet and is conveyed along the rotation direction of the sleeve. In the case of a one-component developer composed only of toner, there are magnetic and non-magnetic developers. In the non-magnetic case, the developing roller is replaced with a magnet roller on the surface. By using a roller provided with rubber or the like, it is adsorbed to the surface of the developing roller using frictional charging or the like and conveyed.

  The developing roller 17 is provided so that a part of the developing roller 17 is exposed from the opened opening of the developing tank 16, and faces the photosensitive member 4 that is rotated at the exposed portion. This opposing position is the development position, and the toner is attached to the electrostatic latent image by rubbing the developer conveyed by the rotation of the developing roller 17 against the electrostatic latent image formed on the surface of the photoreceptor 4. Is done. For example, frictionally charged toner is attracted by the electrostatic force of the electrostatic latent image and developed. Before the developer is transported to the developing position where it is rubbed against the photosensitive member 4, the excessive amount adsorbed by the developing roller 17 is removed by the doctor blade 20 so that the amount thereof is always constant. It has become so.

  On the other hand, as shown in FIG. 3, a developer supply opening 24 is formed in the upper wall portion of the developing tank 16, and a developer supply device 25 is fitted into the supply opening 24 from above. . The developer replenishing device 25 includes a container 26. If the developer is a two-component system, for example, a replenishment developer in which a carrier and toner are mixed at a predetermined ratio is stored in the container 26. Has been.

  A developer supply roller (rotating member) 22 that is driven and controlled by a control device (not shown) is provided at the bottom of the image agent supply device 25, that is, the bottom of the container 26. The developer supply roller 22 has a configuration in which, for example, the roller portion 23 wound around the rotation shaft 29 is made of a porous member such as a sponge. When the developer replenishing roller 22 is rotationally driven, the replenishment developer flows down from the developer replenishing device 25 by an amount corresponding to the driving time of the developer replenishing roller 22 and is supplied into the developing tank 16. The mixture is stirred and conveyed by the agitating and conveying screws 18 and 19.

  Hereinafter, a sealing mechanism that can prevent the above-described intrusion of the developer according to the present invention with a simple configuration that does not require the control of the pressing pressure and that is excellent in recyclability will be described.

  As described above, the sealing mechanism according to the present invention is applied to the developer supply roller 22 that is a rotating member provided in the developer supply device 25. A rotation shaft 29 extending to both ends of the developer supply roller 22 is pivotally supported between opposite side walls of the container 26. As shown in FIG. 1, one end of the rotary shaft 29 is pivotally supported by a bearing 30 provided on a side wall 26a of the container 26 and protrudes from the container 26. A gear (not shown) or the like is attached. Further, the other end portion of the rotating shaft 29 is also pivotally supported by a bearing (not shown) provided on a side wall (not shown) facing the side wall 26 a of the container 26.

  The rotary shaft 29 is provided with an annular seal ring (seal ring member) 40 so as to prevent the developer as a powder from entering between the rotary shaft 29 and the bearing 30. The seal ring 40 is fixed to the bearing 30, and the seal ring 40 and the bearing 30 prevent the developer from entering between the rotary shaft 29 and the bearing 30 as will be described later. The mechanism is configured.

  The seal ring 40 is made of, for example, an elastic material such as rubber or elastomer, and has a shallow lid shape whose outer shape viewed from the axial direction of the rotary shaft 29 is circular. Specifically, the seal ring 40 is formed on the thin ring main body 41, the thick annular fitting part 42 erected on the outer periphery of the ring main body 41, and the ring main body 41, and the rotation It consists of an insertion hole 43 through which the shaft 29 is inserted. The inner diameter of the insertion hole 43 is set to be smaller than the outer diameter of the rotary shaft 29, and the portion where the insertion hole 43 is formed in the ring main body 41 becomes a bellows. It comes in contact with pressure.

  The appropriate pressure referred to here is that the pressure is too weak so that the developer does not enter the seal ring 40 from between the insertion hole 43 and the rotary shaft 29 and the pressure is too strong. Thus, when the rotating shaft 29 rotates, the pressure does not prevent the rotating shaft 29 from sliding smoothly in the insertion hole 43. As a result, the developer can be prevented from entering the seal ring 40 from between the insertion hole 43 and the rotary shaft 29.

  As described above, such a seal ring 40 is fixed to the bearing 30 provided on the side wall 26 a on the inner side of the container 26. Specifically, an annular fitting portion 42 erected on the outer peripheral portion of the ring main body 41 is fixed by fitting into an annular fitting groove 33 formed in the bearing 30.

  The bearing 30 has a configuration in which a shaft hole 32 through which the rotary shaft 29 is inserted is formed in the main body 31, and is one surface of the main body 31, and is fixed to the side wall 26 a of the container 26. An annular fitting groove 33 is formed in the inwardly facing surface 31a. The groove width of the annular fitting groove 33 is set smaller than the thickness of the annular fitting portion 42 formed in the seal ring 40. Therefore, the annular fitting portion 42 of the seal ring 40 has an appropriate fitting pressure in a state where it is fitted in the annular fitting groove 33.

  The appropriate fitting pressure referred to here is that the pressure is too weak, the seal ring 40 does not rotate with the rotation of the rotating shaft 29, and the fitting pressure is too strong. A flaw that runs from the insertion hole 43 is generated in the ring main body 41, and a gap is formed between the insertion hole 43 and the rotary shaft 29, so that the developer can pass through. The pressure is such that the developer does not enter inside (a toner having a smaller diameter in the case of a two-component system).

  In other words, the groove width of the annular fitting groove 33 of the bearing 30 with respect to the thickness of the annular fitting portion 42 of the seal ring 40 does not cause the seal ring 40 to rotate with the rotation of the rotary shaft 29. In addition, the diameter of the insertion hole 43 in a state fitted to the bearing 30 (when the tightening amount is applied) is smaller than the diameter of the insertion hole 43 in a state where the bearing 30 is not fitted (when the tightening amount is not applied). It is set to become.

  Further, it is more desirable as a fitting pressure that the annular fitting portion 42 of the seal ring 40 has in the state fitted in the annular fitting groove 33, even if the developer supply roller 22 provided with the rotating shaft 29 is detached. The seal ring 40 together with the rotary shaft 29 has a fitting pressure that does not come off from the bearing 30.

  In detail, the annular fitting groove 33 is annular in shape when viewed from the axial direction of the rotary shaft 29, and is erected on the inner periphery and the outer periphery so as to be concentric with the shaft hole 32 in the surface 31a. The inner circumferential side annular standing portion 34 and the outer circumferential side annular standing portion 35 are configured.

  In the present embodiment, the outer diameter of the inner peripheral ring-shaped standing portion 34 is larger than the inner diameter of the annular fitting portion 42 in the seal ring 40, and the inner diameter of the outer peripheral-side annular standing portion 35 is annular in the seal ring 40. The outer diameter of the fitting portion 42 is set smaller. Therefore, the annular fitting portion 42 of the seal ring 40 is fastened to the inner circumferential side annular standing portion 34 with an appropriate pressure from the outer circumferential side while being fitted in the annular fitting groove 33, and the outer circumferential side annular standing portion is provided. The action of pushing up the portion 35 from the inner peripheral side with an appropriate pressure is performed, and an appropriate fitting pressure is obtained.

  According to such a configuration, as the developer supply roller 22 rotates, that is, the rotation shaft 29 rotates, the outer surface of the rotation shaft 29 slides on the bellows of the seal ring 40 that is tightened with an appropriate pressure. The developer is prevented from entering the seal ring 40 from between the insertion hole 43 and the rotary shaft 29, and consequently the developer is prevented from entering the rotary shaft 29 and the bearing 30. It will be.

  Further, in the present embodiment, as shown in FIG. 1, in the bearing 30, the outer circumferential side annular standing portion 35 is formed higher than the inner circumferential side annular standing portion 34, and the developing having the rotating shaft 29 is performed. The outer diameter of the agent replenishing roller 22, that is, the outer diameter of the roller portion 23 is set larger than the outer diameter of the inner peripheral side annular standing portion 34 and smaller than the inner diameter of the outer peripheral side annular standing portion 35. The axial direction end portion 23 a of the portion 23 is configured to be fitted inside the outer peripheral side annular standing portion 35.

  As a result, the insertion hole forming portion (bellow) of the ring main body portion 41 exhibiting a sealing function at the axial end portion 23a fitted inside the outer peripheral annular standing portion 35 is shielded from the space portion in the container 26. As a result, the amount of the developer pushed toward the seal ring 40 can be reduced, and the sealing performance can be further improved.

  As described above, the seal mechanism according to the present invention includes the seal ring 40 that is mounted around the rotating shaft 29 of the developer supply roller 22 and the bearing 30 that fixes the seal ring 40 by fitting. Therefore, as compared with a sealing mechanism using a V-ring, the configuration is simple because it is not necessary to manage axial pressure.

  Moreover, in the seal ring 40, a thick annular fitting portion 42 formed on the outer periphery of the ring main body portion 41 is fitted into an annular fitting groove 33 formed in the bearing 30 without using an adhesive or the like. In addition to being easy to disassemble at the time of recycling, there is no need for a step of removing the adhesive, etc., so that the recyclability is excellent.

  In particular, in the present embodiment, since the seal mechanism according to the present invention is applied to the developer supply roller 22 that is intermittently driven only during the developer supply operation, even a simple seal mechanism is in the middle. It is possible to endure until the lifetime of the main body of the apparatus comes without the need for parts replacement. Of course, the sealing mechanism according to the present invention can be applied to the lower developing roller 17 and the rotating members such as the agitating and conveying screws 18 and 19.

  Next, an embodiment of a seal mechanism composed of the seal ring 40 and the bearing 30 will be described with reference to FIGS.

  4A and 4B show design dimensions of the seal ring 40 and the bearing 30 constituting the seal mechanism in the present embodiment. The material of the seal ring 40 in this embodiment is chloroprene rubber (CR), and the material of the bearing 30 is polyacetal (POM). The material of the rotating shaft 29 is stainless steel.

  As shown in FIG. 4A, when the outer diameter of the rotation shaft 29 of the developer supply roller 22 is Φ6.0 mm (tolerance: +0, −0.012 mm), the shaft formed in the main body 31 of the bearing 30. The hole 32 has a diameter of Φ6.0 mm (tolerance: +0.01 to +0.05 mm), and is designed to ensure a clearance of +0.01 to 0.062 mm.

  On the other hand, as shown in FIG. 4B, in the seal ring 40, when the thickness of the ring main body portion 41 where the insertion hole 43 is formed is 0.5 mm, the size of the insertion hole 43 is the diameter. It is designed to have a diameter of 5.6 mm (tolerance: ± 0.2 mm). Since the thickness of the ring main body portion 41 in which the insertion hole 43 is formed is sufficiently thin as 0.5 mm, the bellows that is the insertion hole forming portion absorbs the difference in the outer diameter from the rotation shaft 29 and is appropriate. The pressure makes contact with the outer periphery of the rotary shaft 29.

  On the other hand, the height of the annular fitting portion 42 in the seal ring 40 is designed to be 2.5 mm including the thickness of the ring main body portion. The height of the outer circumferential side annular standing portion 35 and the inner circumferential side annular standing portion 34 on the bearing 30 side that is in contact with the outer circumferential surface or inner circumferential surface of the annular fitting portion 42 is determined by the height of the outer circumferential surface or inner circumferential surface. Designed to contact the entire surface.

  In such a design, if the outer diameter of the annular fitting portion 42 of the seal ring 40 is Φ13.0 mm (tolerance: +0.2 mm, −0), the inner diameter of the outer circumferential side annular standing portion 35 in the bearing 30 is − When the inner diameter of the annular fitting portion 42 of the seal ring 40 is Φ10.0 mm (tolerance: +0, −0.2 mm), the inner circumferential side annular shape of the bearing 30 is designed to fit 0.05 to −0.15 mm. The outer diameter of the upright portion 34 is designed to fit between +0 and 0.3 mm.

  By adopting such a design, the inner diameter of the outer circumferential annular standing portion 35 in the bearing 30 is 0.05 to 0.35 mm smaller than the outer diameter of the annular fitting portion 42 of the seal ring 40. (Tightening amount) Thus, the seal ring 40 can be fixed to the bearing 30 without the seal ring 40 being accompanied by the rotation of the rotating shaft 29 and without the seal ring 40 being wavy.

  FIG. 5 shows the difference between the inner diameter of the outer circumferential annular standing portion 35 of the bearing 30 and the outer diameter of the annular fitting portion 42 of the seal ring 40 in the seal mechanism comprising the seal ring 40 and the bearing 30 of this embodiment. The relationship between a certain tightening amount and the torque between the seal ring 40 and the bearing 30 (torque between the outer surface of the annular fitting portion of the seal ring 40 and the inner surface of the outer circumferential annular standing portion of the bearing 30). The results of the investigation are shown.

The accompanying rotation of the seal ring 40 occurs when the torque between the insertion hole 43 and the rotary shaft 29 when the developer supply roller 22 is started exceeds the torque between the seal ring 40 and the bearing 30. In the sealing mechanism of the present embodiment, the amount of biting of the insertion hole 43 with respect to the rotation shaft 29 is 0.59 mm, and the torque between the insertion hole 43 and the rotation shaft 29 when left in a high temperature and high humidity environment for 12 hours is 50 gf · cm (4.9 × 10 ⁻³ J).

Therefore, as shown in FIG. 5, the torque between the seal ring 40 and the bearing 30 can be increased by setting the tightening amount to 0.05 mm or more in both a low temperature and low humidity environment (LL environment) and a normal temperature and normal humidity environment (NN environment). 150 gf · cm (14.7 × 10 ⁻³ J) or more can be secured, and the rotation of the seal ring 40 can be avoided.

  Further, if the fitting pressure of the annular fitting portion 42 with respect to the annular fitting groove 33 becomes too strong, wrinkles and the like are likely to occur in the ring main body portion 41. Therefore, three samples A, B, and C selected at random are selected. Was used to measure the amount of eccentricity of the insertion hole 43 in the seal ring 40. The amount of eccentricity is represented by the difference between the maximum value and the minimum value of the inner diameter of the insertion hole 43.

  As a result of the measurement, as shown in FIG. 6, a maximum difference of 0.063 mm was obtained with a tightening amount of 0.35 mm, but by applying the tightening amount, any of the diameters when the tightening amount was 0 Also in the case, the diameter was reduced, and no increase in diameter was observed. As a result of confirming the influence with the toner having an average particle diameter of 6.7 μm, this difference is within an allowable range, and the upper limit of the tightening amount is set to 0.35 mm, thereby preventing the developer from slipping through the seal ring 40. it can.

  Further, in FIG. 7, in the seal mechanism composed of the seal ring 40 and the bearing 30 of the present embodiment, the inner diameter of the outer peripheral side annular standing portion 35 in the bearing 30 and the annular shape of the seal ring 40 are used using the above three samples. The result of having investigated the relationship between the tightening amount which is a difference with the outer diameter of the fitting part 42, and the extraction force which the seal ring 40 remove | deviates from the bearing 30 is shown.

In the seal mechanism of this embodiment, the amount of biting of the insertion hole 43 with respect to the rotation shaft 29 is 0.59 mm, and the removal force of the rotation shaft 29 in a state of being left for 12 hours in a high temperature and high humidity environment is 60 gf (5.8). X10 ⁻¹ N).

Therefore, as shown in FIG. 7, in any of the above three samples, the removal force at a tightening amount of 0.05 mm to 0.35 mm regardless of the low temperature and low humidity environment (LL environment) or the normal temperature and normal humidity environment (NN environment). Is in the range of 100 gf (9.8 × 10 ⁻¹ N) to 600 gf (5.88 N), and the seal ring 40 can be prevented from coming off together with the rotary shaft 29.

FIG. 2 is a cross-sectional view illustrating an embodiment of the present invention and enlarging one side wall portion of a container of a developer supply device. It is sectional drawing which shows one structural example of the image forming apparatus with which the developing device equipped with the said developer supply apparatus is mounted. It is sectional drawing which shows one structural example of the developing device provided with the said developer supply apparatus. (A) (b) is sectional drawing which shows the specific structure of one Example of a sealing mechanism. In the seal mechanism of the above-described embodiment, the relationship between the tightening amount, which is the difference between the inner diameter of the outer circumferential annular standing portion of the bearing and the outer diameter of the annular fitting portion of the seal ring, and the torque between the seal ring and the bearing It is a graph which shows. In the seal mechanism of the above embodiment, the relationship between the tightening amount, which is the difference between the inner diameter of the outer circumferential annular standing portion of the bearing and the outer diameter of the annular fitting portion of the seal ring, and the eccentric amount of the insertion hole of the seal ring. It is drawing which shows the result of having investigated. It is a graph which shows the relationship between the tightening amount which is the difference of the internal diameter of the outer peripheral side annular standing part of a bearing, and the outer diameter of the cyclic | annular fitting part of a seal ring, and seal removal force in the seal mechanism of the said Example.

Explanation of symbols

8 Developing Device 22 Developer Supply Roller 23 Roller 23a Axial End 25 Developer Supply Device 26 Container 26a Side Wall 29 Rotating Shaft 30 Bearing 33 Annular Fitting Groove 34 Outer Circumferential Ring Standing Portion 35 Inner Peripheral Ring Standing Portion 40 Seal ring (seal ring member)
42 annular fitting part 43 insertion hole

Claims (5)

A seal mechanism for preventing powder from entering between a rotating shaft supported between opposing side walls of a container in which powder is accommodated and a bearing supporting the rotating shaft,
The diameter of the insertion hole formed in the thin ring main body portion through which the rotation shaft is inserted is set smaller than the outer diameter of the rotation shaft, and the outer peripheral portion is thick. An elastic seal ring member having an annular fitting portion formed thereon;
The shaft has a shaft hole through which the rotating shaft is inserted, and has an annular fitting groove formed concentrically with the shaft hole, into which an annular fitting portion formed in the seal ring member is fitted, and A bearing in which the groove width of the annular fitting groove is set smaller than the thickness of the annular fitting portion,
The seal ring member is fixed to the bearing by fitting the annular fitting portion into the annular fitting groove of the bearing, and the outer periphery of the rotating shaft is rotated with the rotation of the rotating shaft. A sealing mechanism characterized by sliding through an insertion hole forming portion.   The width of the annular fitting groove of the bearing with respect to the thickness of the annular fitting portion of the seal ring member does not cause the seal ring member to rotate with the rotation of the rotating shaft, and provides a tightening amount. The diameter of the insertion hole of the seal ring member when the tightening amount is applied is set to be smaller than the diameter of the insertion hole of the seal ring member when not. The sealing mechanism as described.   The groove width of the annular fitting groove of the bearing relative to the thickness of the annular fitting portion of the seal ring member is such that the seal ring member does not come off together with the rotary shaft when the rotary shaft is detached from the bearing. The sealing mechanism according to claim 2, wherein the sealing mechanism is set as follows.   The annular fitting groove of the bearing is composed of an annular standing portion erected on the inner periphery and the outer periphery, the annular standing portion on the outer peripheral side is higher than the annular standing portion on the inner periphery side, and The outer diameter of the roller having the rotating shaft is set to be larger than the outer diameter of the annular standing portion on the inner circumferential side and smaller than the inner diameter of the annular standing portion on the outer circumferential side, and the axial end of the roller is the outer circumference The seal mechanism according to claim 1, wherein the seal mechanism is fitted inside the annular standing portion on the side. A developer container, and a developer replenishing roller having a rotation shaft supported between opposite side walls of the container, and the developer replenishing roller rotates the developer in the container. A developer replenishing device for replenishing
A seal mechanism for preventing powder from entering between the rotating shaft of the developer supply roller and a bearing that supports the rotating shaft;
The seal mechanism is mounted on the rotating shaft, and the diameter of the insertion hole formed in the thin ring main body portion through which the rotating shaft is inserted is set smaller than the outer diameter of the rotating shaft, and the outer periphery A seal ring member having elasticity with a thick annular fitting formed in the part and a shaft hole through which the rotating shaft is inserted, and formed concentrically with the shaft hole, formed on the seal ring member A bearing having an annular fitting groove into which the annular fitting portion is fitted, and a groove width of the annular fitting groove set smaller than a thickness of the annular fitting portion, The seal ring member is fixed to the bearing by fitting the annular fitting portion into the annular fitting groove of the bearing, and the outer periphery of the rotating shaft is rotated with the rotation of the rotating shaft. Developer replenishing device characterized in that it slides through an insertion hole forming portion

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