JP2021196566A - Bearing member, bearing mechanism, developing device, and image forming apparatus - Google Patents

Abstract

To provide a bearing member that can prevent an increase in temperature due to heat generated from a bearing part despite a device configuration having a rotation shaft with the high number of rotations.SOLUTION: A bearing member 120 is for receiving a shaft 101, and is provided with an inside bearing part 130, an outside bearing part 140 that rotatably holds the inside bearing part 130, a seal member 151 for sealing the space between the shaft 101 and the inside bearing part 130, and a seal member 152 for sealing the space between the inside bearing part 130 and the outside bearing part 140. The two seal members are arranged at positions where their rubbing parts are different in an axial direction.SELECTED DRAWING: Figure 1

Description

The present invention relates to a bearing member, a bearing mechanism, a developing device and an image forming device.

Conventionally, a bearing member for receiving a shaft is known. For example, Patent Document 1 describes the following developing apparatus provided with such a bearing member. In this developing apparatus, the rotating shaft of the stirring member that rotates in the apparatus main body and stirs the developer in the apparatus main body is rotatably supported by the bearing portion. A sealing member is provided on the device main body side of the bearing portion so as to penetrate the rotating shaft. A heat transfer member having high thermal conductivity is arranged so as to surround the vicinity of the bearing portion, and a heat dissipation member that dissipates heat transmitted from the heat transfer member is provided toward the outside of the main body of the apparatus. The heat generated in the bearing portion during driving is dissipated from the heat radiating member via the heat transfer member.

However, in a device configuration in which the rotation speed of the rotating shaft is high, there is a possibility that the temperature rise due to heat generation of the bearing portion cannot be sufficiently suppressed.

In order to solve the above-mentioned problems, the present invention is a bearing member for receiving a shaft, the inner bearing portion, the outer bearing portion that rotatably holds the inner bearing portion, the shaft, and the above. It is characterized by providing a sealing member for sealing between the inner bearing portions and a sealing member for sealing between the inner bearing portion and the outer bearing portion.

According to the present invention, it is possible to suppress a temperature rise due to heat generation of the bearing portion even in an apparatus configuration in which the rotation speed of the rotating shaft is high.

The schematic block diagram of an example of the bearing mechanism which concerns on embodiment. The schematic block diagram of another example of the bearing mechanism which concerns on embodiment. Schematic diagram of a printer which is an image forming apparatus. Schematic diagram of the image forming section of the printer. Explanatory drawing of the configuration example of the toner replenishment device of the printer. Explanatory drawing of another configuration example of a rotary bearing. Explanatory drawing of still another configuration example of a rotary bearing. Explanatory drawing of still another configuration example of a rotary bearing. A graph showing the measurement result of temperature rise.

An embodiment in which the present invention is applied to a bearing mechanism in a developing device of an image forming apparatus will be described. FIG. 1 is a schematic configuration diagram of an example of a bearing mechanism according to an embodiment. Each example of FIGS. 1 (a) and 1 (b) includes a bearing member 120 that receives a shaft 101 of a transport member 100 for transporting a developer or toner. The transport member 100 has a screw blade 102 on the shaft 101, and transports the developer or toner in the transport path forming member 103. The bearing member 120 includes a rotary bearing 130 as an inner bearing portion and a fixed bearing 140 as an outer bearing portion that rotatably holds the rotary bearing 130. It has a first sealing member 151 for sealing between the shaft 101 and the rotary bearing 130, and a second sealing member 152 for sealing between the rotary bearing 130 and the fixed bearing 140. The two sealing members 151 and 152 are arranged so that the rubbing portions are generated at different positions in the axial direction.

The rotary bearing 130 supports the shaft 101, the fixed bearing 140 supports the rotary bearing 130, and the shaft 101 and the rotary bearing 130, and the rotary bearing 130 and the fixed bearing 140 slide, respectively. Drive gears 160 and 161 are attached to the right ends of the shaft 101 and the rotary bearing 130 in the drawing, respectively. Drive is input to these drive gears 160 and 161 by meshing the gears. As shown in FIG. 1A, the shaft drive input gear 170 and the bearing drive input gear 171 can be meshed with each other to drive and input independently of each other. Instead of this, as shown in FIG. 1 (b), the gears of the respective diameter portions 173a and 173b of one stepped gear 173 may be meshed with the drive input gear for drive input. When the stepped gear 173 is used, it is expected that the assembling property and the parts cost will be reduced by reducing the number of parts. In any case, the shaft 101 and the rotary bearing 130 are driven to rotate in the same direction at different rotation speeds.

For example, if the rotation speed of the rotary bearing 130 is halved (example: 350 rpm) with respect to the target shaft rotation speed (example: 700 rpm), the relative rotation speed of the shaft 101 and the rotary bearing 130, and the rotary bearing 130 and the fixed bearing 140. Both become 350 rpm. By doing so, the heat generated by the sliding portion is dispersed in two places. Specifically, it is dispersed in the sliding portion between the shaft 101 and the rotary bearing 130 and the sliding portion between the rotary bearing 130 and the fixed bearing 140. As a result, it is possible to reduce the temperature rise around the bearing as compared with the case where the target rotation speed is locally set at one place without being dispersed. The relative rotation speed does not have to be half of the target shaft rotation speed. It can be set relatively freely depending on the design of the gear.

FIG. 2 shows one or more stages of bearings between the rotary bearing 130 and the fixed bearing 140, in which the relatively inner bearing portion is rotatably held and the relatively outer bearing portion is rotatably held. It is a structure to have. In the figure, an additional two-stage rotary bearing 130 (130b, 130c) is provided between the rotary bearing 130a that directly receives the shaft and the fixed bearing 140. This is a bearing and a bearing mechanism in which the relative rotation speed at each sliding portion is further reduced and heat generation at each portion is suppressed. By making the diameter of the bearing gear of each rotary bearing 130 larger than the diameter of the bearing gear held by the rotary bearing 130 and smaller than the diameter of the bearing gear held by the rotary bearing 130, the bearing can be rotated with respect to the rotation speed of the shaft. The relative rotation speed can be gradually reduced.

In the illustrated example, all gears are driven by the stepped gear 174. The tooth portions 174a to 174d of the stepped gear 174 mesh with the gear 160 of the shaft 101 and the drive gears (161a to 161c) of the rotary bearings 130 (130a to 130c). The second seal members 151a to 153c are seal members that seal between the rotary bearings 130.

3 to 5 show configuration examples of an image forming apparatus, a developing apparatus thereof, and a toner replenishing apparatus thereof. FIG. 3 is a schematic diagram showing a schematic configuration of a printer 1 which is an image forming apparatus. The printer 1 can detachably (replaceably) install four toner containers 32 (Y, M, C, K) corresponding to each color (yellow, magenta, cyan, black) on the upper part of the housing. An intermediate transfer unit 85 is provided below the toner container 32 (Y, M, C, K).

An image forming unit 46 (Y, M, C, K) corresponding to each color is provided side by side with the intermediate transfer belt 48 of the intermediate transfer unit 85 so as to face from below. Below the toner container 32 (Y, M, C, K), a toner replenishing device 60 (Y, M, C, K) is provided, respectively. The toner contained in the toner container 32 (Y, M, C, K) is stored in the image forming unit 46 (Y, M, C, K) by the toner replenishing device 60 (Y, M, C, K), respectively. It is supplied (supplied) into the developing apparatus 50 (Y, M, C, K) as the developing means.

The four toner containers 32 (Y, M, C, K) corresponding to each color, the image forming unit 46 (Y, M, C, K) and the toner replenishing device 60 (Y, M, C, K) are used. The configuration is the same except that the toner colors are different. In the following description and drawings, the subscripts "Y", "M", "C", and "K" indicating the color of the toner to be used will be omitted as appropriate.

FIG. 4 is a schematic diagram showing a schematic configuration of one of the four image forming units 46, 46Y. The image-creating unit 46 includes a photoconductor 41 as a latent image carrier, a charging unit 44 arranged around the photoconductor 41, a developing device 50, a cleaning unit 42, a static elimination unit, and the like. Then, an image forming process (charging step, exposure step, developing step, transfer step, cleaning step) is performed on the photoconductor 41 to form an image of each color on the photoconductor 41.

The photoconductor 41 is rotationally driven clockwise in FIG. 4 by a drive motor. The charging unit 44 uniformly charges the surface of the photoconductor 41 (charging step). After that, the surface of the photoconductor 41 reaches the irradiation position of the laser beam L emitted from the exposure apparatus 47. The exposure apparatus 47 forms an electrostatic latent image corresponding to each color by exposure scanning at this position (exposure step). After that, the surface of the photoconductor 41 reaches a position facing the developing device 50. The developing device 50 develops an electrostatic latent image at this position to form a toner image of each color (development step). After that, the surface of the photoconductor 41 is a primary transfer portion facing the primary transfer roller 49 with the intermediate transfer belt 48 interposed therebetween, and the toner image on the photoconductor 41 is transferred onto the intermediate transfer belt 48 (primary transfer step). A color image is formed on the intermediate transfer belt 48 by superimposing and transferring the toner image of each color formed on the photoconductor 41 of each color on the intermediate transfer belt 48.

A small amount of untransferred toner remains on the surface of the photoconductor 41 that has passed through the primary transfer portion. After that, the surface of the photoconductor 41 reaches a position facing the cleaning portion 42. At this position, the cleaning blade 42a mechanically recovers the untransferred toner remaining on the photoconductor 41 (cleaning step). Finally, the surface of the photoconductor 41 reaches a position facing the static elimination unit. Here, the static elimination unit removes the residual potential on the photoconductor 41.

The intermediate transfer unit 85 includes an intermediate transfer belt 48, four primary transfer rollers 49 (Y, M, C, K), a secondary transfer backup roller 82, a plurality of tension rollers, an intermediate transfer cleaning unit, and the like. The intermediate transfer belt 48 is stretched and supported by a plurality of tension rollers, and is endlessly moved in the counterclockwise direction in FIG. 3 by the rotational drive of the secondary transfer backup roller 82 among the roller members. The four primary transfer rollers 49 (Y, M, C, K) each sandwich the intermediate transfer belt 48 with the photoconductor 41 (Y, M, C, K) to form a primary transfer nip. ..

Then, a transfer bias opposite to the polarity of the toner is applied to the primary transfer roller 49 (Y, M, C, K). The intermediate transfer belt 48 travels in the direction of the arrow and sequentially passes through the primary transfer nips of the respective primary transfer rollers 49 (Y, M, C, K). In this way, the toner images of each color on the photoconductor 41 (Y, M, C, K) are superimposed on the intermediate transfer belt 48 and primary transfer is performed.

The intermediate transfer belt 48 on which the toner images of each color are superimposed and transferred reaches the secondary transfer portion facing the secondary transfer roller 89. In the secondary transfer unit, an intermediate transfer belt 48 is sandwiched between the secondary transfer backup roller 82 and the secondary transfer roller 89 to form a secondary transfer nip. The four-color toner image formed on the intermediate transfer belt 48 is transferred onto a recording medium P such as transfer paper conveyed to the position of the secondary transfer nip. At this time, untransferred toner that has not been transferred to the recording medium P remains on the intermediate transfer belt 48. After that, the intermediate transfer belt 48 reaches the position of the intermediate transfer cleaning unit, and the untransferred toner on the intermediate transfer belt 48 is collected. In this way, a series of transfer processes performed on the intermediate transfer belt 48 is completed.

The recording medium P conveyed to the position of the secondary transfer nip is conveyed from the paper feed unit 26 arranged below the main body of the apparatus via the paper feed rollers 26a, 27a, the resist roller pair 28, and the like. Is. Specifically, a plurality of recording media P are stacked and stored in the paper feed units 26 and 27. Then, the paper feed rollers 26a and 27a are rotationally driven in the counterclockwise direction in FIG. 3, and the top recording medium P is fed between the rollers of the resist roller vs. 28. The resist roller pair 28 that has stopped the rotation drive temporarily stops the recording medium P that has been conveyed to the resist roller pair 28 by the roller nip. Then, the resist roller pair 28 is rotationally driven in time with the color image on the intermediate transfer belt 48, and conveys the recording medium P toward the secondary transfer nip. In this way, the desired color image is transferred to the recording medium P.

The recording medium P on which the color image is transferred by the secondary transfer nip is conveyed to the fixing device 86. The fixing device 86 fixes the color image transferred to the surface on the recording medium P by the heat and pressure of the fixing belt and the pressure roller. After that, the fixing device 86 feeds the recording medium P between the rollers of the paper ejection roller vs. 29. The paper ejection roller pair 29 ejects the recording medium P out of the apparatus and sequentially stacks it on the stack portion 30. In this way, the printer 1 completes a series of image forming processes.

Next, the configuration and operation of the developing device 50 in the image forming unit will be described in more detail.
As shown in FIG. 4, the developing apparatus 50 includes a developing roller 51 facing the drum-shaped photoconductor 41, a doctor blade 52 facing the developing roller 51, a first developing agent accommodating portion 53, and a second developing agent accommodating portion 54. It is provided with two transport screws 55 arranged inside. Further, a toner concentration sensor 56 for detecting the toner concentration in the developer of the first developer accommodating unit 53 is provided. The developing roller 51 includes a magnet fixed inside, a sleeve that rotates around the magnet, and the like. The developer accommodating portion (53, 54) accommodates a two-component developer G composed of a carrier and a toner. The second developer accommodating portion 54 includes a toner supply port 57 formed above the second developer accommodating portion 54.

The sleeve of the developing roller 51 is rotationally driven in the arrow direction (counterclockwise direction) in FIG. Then, the developer G supported on the developing roller 51 by the magnetic field formed by the magnet moves on the developing roller 51 as the sleeve rotates. The developer G in the developing apparatus 50 is adjusted so that the ratio of toner (toner concentration) in the developing agent is within a predetermined range. The toner replenishment device 60 replenishes the toner stored in the toner container 32 into the second developer storage unit 54 via the toner replenishment port 57 according to the toner consumption in the developing device 50. The configuration and operation of the toner replenishing device will be described in detail later.

The toner replenished in the second developer accommodating portion 54 circulates in the two developer accommodating portions (53, 54) while being mixed and stirred together with the developer G by the two transfer screws 55. Then, the toner in the developer G is adsorbed on the carrier by triboelectric charging with the carrier, and is supported on the developing roller 51 together with the carrier by the magnetic force formed on the developing roller 51. The developer G supported on the developing roller 51 reaches the position of the doctor blade 52.

Then, the developer G on the developing roller 51 is conveyed to a position facing the photoconductor 41 (development region) after the amount of the developer is adjusted to an appropriate amount at this position. The latent image formed on the photoconductor 41 adsorbs toner by the electric field formed in the developing region. After that, the developer G remaining on the developing roller 51 reaches the upper part of the first developing agent accommodating portion 53 as the sleeve rotates, and is separated from the developing roller 51 at this position.

FIG. 5 is a schematic view showing a toner replenishing device 60 and a toner container 32 set in the toner replenishing device 60 by taking the one for Y as an example. The toner replenishment device 60 includes a transfer nozzle 611 as a transfer path forming member, a transfer screw 614, a toner drop transfer tube 64, a sub hopper 63 as a storage unit, a bottle side drive mechanism unit 91 as a developer replenishment mechanism, and a sub hopper side drive mechanism unit. It has 92, a supply pipe 61, a supply screw 62, and the like.

When the toner container 32 is inserted into the set cover 608 of the toner replenishing device 60 in the direction of arrow A in the figure and mounted, the toner replenishing device 60 is attached to the tip end side of the toner container 32 in conjunction with the mounting operation. The transfer nozzle 611 is inserted, and the inside of the toner container 32 and the inside of the transfer nozzle 611 communicate with each other.

The toner container 32 has a cylindrical shape, and includes a container tip cover 34 to be inserted into the set cover 608, a toner bottle 33 integrally formed with a container rotation gear 301, and the like. The container tip cover 34 rotatably holds the toner bottle 33 in a state of receiving the tip portion of the toner bottle 33 in the direction of the rotation axis. The container tip cover 34 includes an ID chip 700 as an information storage unit. The ID chip 700 records data such as the color, composition, characteristics including components of the contained toner, production lot number, and usage status. The set cover 608 is provided with an ID chip connector 701 for making an electrical connection with the ID chip 700. A barcode, QR code (registered trademark), or the like may be provided in place of the ID chip 700, and the set cover 608 may be provided with a reading means corresponding to these.

With the container tip cover 34 of the toner container 32 inserted into the set cover 608 of the toner replenishment device 60, the bottle-side drive mechanism unit 91 composed of a drive motor, a drive gear, etc. is the container rotation gear 301 of the toner container 32. The rotational driving force is transmitted to. As a result, the toner bottle 33 of the toner container 32 is rotationally driven in the direction of arrow B in the drawing while being held by the container tip cover 34. Along with this rotational drive, the spiral protrusion 302 formed spirally on the inner peripheral surface of the toner bottle 33 also rotates. By this rotation, the toner contained in the toner bottle 33 is conveyed from the rear end side to the tip side (from the left side to the right side in FIG. 5) of the bottle. Then, it is supplied into the transport nozzle 611 from the container tip cover 34.

A transfer screw 614 as a powder transfer member is arranged in the transfer nozzle 611, and rotates integrally with a transfer screw gear 605 fixed to an end portion in the longitudinal direction thereof. The bottle-side drive mechanism unit 91 rotationally drives the transfer screw 614 and conveys the toner in the transfer nozzle 611 by outputting the rotational drive force to the transfer screw gear 605.

A toner drop transfer pipe 64 is connected to the downstream end of the transfer nozzle 611 in the toner transfer direction from below in the direction of gravity. The toner conveyed in the transfer nozzle 611 by the transfer screw 614 is dropped from the transfer nozzle 611 into the toner drop transfer tube 64 and gravitationally drops into the sub hopper 63. As a result, toner is replenished in the sub hopper 63. The sub hopper 63 includes a toner amount detection sensor 111 that detects the amount of toner in the sub hopper 63. As the toner amount detection sensor 111, various types of sensors such as a piezoelectric type sensor and a light reflection type can be used.

A supply pipe 61 is connected to the lower part of the sub hopper 63. The sub hopper 63 includes two agitators 66 that are rotationally driven. The two agitators 66 are rotationally driven to transfer toner toward the supply pipe 61. The supply pipe 61 includes a supply screw 62 inside. The sub-hopper side drive mechanism unit 92 can independently transmit the rotational driving force to the two agitators 66 in the sub hopper 63 and the supply screw 62 in the supply pipe 61. By rotationally driving the two agitators 66, the toner in the sub hopper 63 is conveyed toward the replenishment pipe 61, and by rotationally driving the replenishment screw 62, the toner in the sub hopper 63 is replenished into the developing device 50. The sub-hopper side drive mechanism unit 92 can be driven independently of the bottle side drive mechanism unit 91.

Although the toner replenishing device 60 described above replenishes the toner from the toner container 32 to the developing device 50 via the sub hopper 63, the toner from the toner container 32 may be directly supplied to the developing device 50.

It can be applied to bearing mechanisms such as the transfer screw 55 in the developing device 50 of the printer 1, the transfer screw 614 in the toner replenishment device 60, the agitator 66, and the replenishment screw 62.

When applied to a bearing mechanism that supports the transport screw 55 in the developing apparatus 50, the rotary bearing 130 comes into contact with the developer G. FIG. 6 shows an example of the shape of the rotary bearing 130 suitable for such an application location. By providing the shape of the stirring member on the outer periphery of the rotary bearing 130, it is possible to suppress the retention of the developer and the increase in the agent pressure, and it is possible to prevent the developer from leaking from the bearing. FIG. 6A is provided with a paddle-shaped stirring member shape portion 133. FIG. 6B shows an example of the bearing mechanism of FIG. 1 using the rotary bearing 130. FIG. 6C shows an example in which the spiral stirring blade portion 134 is provided. The shape of the stirring member is not limited to these.

FIG. 7 shows another configuration example of the rotary bearing 130. FIG. 7A is a perspective view of a rotary bearing 130 in which the sliding portion with the shaft 101 and the first seal member 151 is made of metal, and FIG. 7B is an example of the bearing mechanism of FIG. 1 using the rotary bearing 130. show. The metal portion 135 is a hatched portion. As in the configuration of FIG. 2, when a plurality of rotary bearings 130 are provided, the same configuration can be adopted, and the metal portion 135 can be used as a portion for supporting the rotary bearing 130 located inside. Since metal has higher heat dissipation than resin, the temperature rise is reduced. As shown in FIGS. 7 (a) and 7 (b), instead of using metal for the portion supporting the shaft 101 and the fixed bearing 140, or in addition to this, as shown in FIGS. 7 (c) and 7 (d). In addition, the portion 136 supported by the fixed bearing 140 may be made of metal. It is preferable to bring the second seal member 152 into contact with this portion. It can also be used as the configuration of each rotary bearing 130 in the configuration of FIG. 2.

FIG. 8 shows still another configuration example of the rotary bearing 130. 8 (a) is a vertical cross-sectional view of the rotary bearing 130 alone, FIG. 8 (b) is a view seen from the right side of FIG. 8 (a), and FIG. 8 (c) is FIG. 1 using the rotary bearing 130. An example of the bearing mechanism is shown. In this rotary bearing 130, a cylindrical metal member 137 (part) is integrated by insert molding into a resin portion to which the first seal member 151 is attached. At least the portion that fits with the fixed bearing 140 (including the portion that comes into contact with the second seal member 152 that attaches to the fixed bearing 140) is composed of only a metal portion. As a result, it is possible to reduce the wall thickness while maintaining the strength as compared with the examples shown in FIGS. 7 (c) and 7 (d) in which the resin portion is present inside the metal portion. If there is no resin, the diameter of the metal part can be made smaller, the sliding speed [V∝metal part diameter] of the fixed bearing 140 and the rotary bearing 130 can be suppressed, and the heat generation [calorific value ∝V] here can be reduced.

A D-cut shape, an oval shape, or a plurality of D-cut shapes (hereinafter, D-cut shapes, etc.) are formed at the end 137a of the tubular metal member, and the D-cut shapes and the like are formed as shown in FIG. 8 (c). The driving force is transmitted to the rotary bearing 130 by fitting the drive gear 161. Since the rotary bearing 130 rotates only the bearing, the rotational load is small, and drive transmission is possible even with a D-cut shape or the like that does not penetrate the metal portion, but a D-cut shape or the like having a size that penetrates the metal shape may be used. In this case, it is preferable to provide a relief shape in the shaft-corresponding portion of the drive gear 161 so that the drive gear 161 fitted to the D-cut shape and the shaft 101 do not interfere with each other. The relief shape is preferably an arc shape having a diameter equal to or larger than the shaft diameter.

The rotary bearing 130 of FIG. 8 can also be used as the configuration of each rotary bearing 130 in the configuration of FIG. However, when the rotary bearing is used in multiple stages as shown in FIG. 2, in order to avoid sliding between the metals, as shown in the examples shown in FIGS. 7 (c) and 7 (d), the contact portion with the inner rotary bearing. A structure in which is a resin is preferable.

In the bearing and bearing mechanism of the embodiment described with reference to FIGS. 1, 2, 6, 7, and 8, the resin portion of the bearing slides by using a slidable resin such as polyacetal. The property is improved and heat generation is reduced. Further, by using a greaseless seal member, the risk of agglomerates of the developer G can be eliminated.

Further, the bearing and the bearing mechanism of the embodiment described with reference to FIGS. 1, 2, 6, 7, and 8 are not limited to the developing device 5Y, but convey the toner replenishing device that replenishes the toner to the developing device 5Y. By providing the member or other rotating shaft on the rotating shaft where the developer / toner in the image forming apparatus may come into contact, it is possible to prevent toner welding due to heat generation.

An example of measuring the temperature rise of the seal portion when the conventional bearing and the bearing of the embodiment of the present application shown in FIG. 1 are continuously driven at 1000 rpm for 1 hour is shown below. The conditions of the components are as shown in Table 1 below.

FIG. 9 shows the measurement of the temperature rise of the conventional seal member, the seal portion (rotary bearing seal portion) by the first seal member 151 of the rotary bearing 130 of the embodiment, and the seal portion (fixed bearing seal portion) by the second seal member 152. It is a graph which shows the result. It is a measurement result of the temperature rise before and after driving when it was driven at 1000 rpm for 1 hour. In this way, the temperature of the rotary bearing 130, which corresponds to the seal portion where the temperature has risen by 27 deg in the past, has been greatly reduced to 14 deg. Further, the seal of the fixed bearing 140 is 17 deg, which is considerably lower than that of the conventional seal 27 deg. The reason why the temperature of the fixed bearing 140 is higher than that of the rotary bearing 130 is that the diameter of the portion where the seal contacts is large, so that the sliding speed is high. (Sliding speed = rotation speed x sliding part diameter x π).

In order to further reduce the temperature rise of the fixed bearing 140, it is necessary to reduce the wall thickness of the contact portion of the rotary bearing 130 with the fixed bearing 140. For example, the thickness of the portion corresponding to the fixed bearing 140 of the rotary bearing 130 is 0. By making it with a thin metal columnar part of .3 mm, it becomes Φ6.6, which can be improved. Further, by using metal, the effect of dispersing the heat generated in the seal portion is added, and it is possible to obtain an effect more than simply reducing the diameter.

The above description is an example, and the present invention exerts a peculiar effect in each of the following aspects.
(Aspect 1)
The basic configuration of the bearing member according to the embodiment is for receiving a shaft. The bearing member according to the embodiment includes an inner bearing portion, an outer bearing portion that rotatably holds the inner bearing portion, a seal member for sealing between the shaft and the inner bearing portion, and the above-mentioned. A sealing member for sealing between the inner bearing portion and the outer bearing portion is provided. Therefore, even in an apparatus configuration in which the rotation speed of the rotating shaft is high, it is possible to suppress a temperature rise due to heat generation of the bearing portion. The bearing portion on the side closer to the center of the shaft that can be received is called "inside", and conversely, the bearing portion on the side farther from the center of the shaft than "inside" is called "outside".

(Aspect 2)
Further, in the bearing member according to the embodiment, the two seal members are arranged so that the rubbing portions are generated at different positions in the axial direction. Therefore, unlike the case where the positions are the same in the axial direction, it is possible to avoid that the heat generating portion {seal portion} is located close to each other and the heat generation is added up and the temperature rises.

(Aspect 3)
Further, in the bearing member according to the embodiment, the relatively inner bearing portion is rotatably held between the inner bearing portion and the outer bearing portion, and the bearing member is rotatable to the relatively outer bearing portion. It has one or more stages of bearings that are held in. Therefore, by providing a plurality of bearings that are rotatably held and held rotatably by themselves, the relative rotation speed at each sliding portion is further reduced, so that local heat generation can be suppressed.

(Aspect 4)
Further, in the bearing mechanism according to the embodiment, in the bearing member according to the third aspect, the one or more stages of the bearing portion rotatably held by the relatively outer bearing portion is a metal member having a cylindrical shape to be held. A resin member is provided inside the metal member. Therefore, the sliding is performed by the metal and the resin, and the heat generation due to the sliding can be suppressed as compared with the case where the metals are used with each other. For example, it is preferable that the portion in contact with the seal portion of the bearing to be held as shown in FIG. 7D is formed of a metal portion, and a resin portion or a coat layer having good slidability is provided inside the metal portion. This is to avoid sliding between metals. It is preferable to form the thickness of the resin thin so that the diameter does not become large, and for example, a thin resin portion is formed by using laser treatment, plasma treatment, or the like. Alternatively, nano-level dimples are formed on the inner wall of the metal part as a surface treatment and then injection molded. These make it possible to firmly integrate the metal and the resin even in a thin layer.

(Aspect 5)
Further, in the bearing mechanism according to the embodiment, the bearing member rotates integrally with the inner bearing portion, the outer bearing portion that rotatably holds the inner bearing portion, and the inner bearing portion. It has a gear, and the first gear has a smaller diameter than the second gear. Therefore, by making the diameter of the first gear attached to the shaft smaller than that of the second gear attached to the inner bearing, the rotation speed of the inner bearing becomes smaller, and the relative rotation speed can be made smaller.

(Aspect 6)
Further, in the bearing mechanism according to the embodiment, the bearing member rotatably holds a relatively inner bearing portion between the inner bearing portion and the outer bearing portion, and is relatively outer. It has one or more stages of bearings that are rotatably held in the bearings. Therefore, by providing a plurality of bearings that are rotatably held and held rotatably by themselves, the relative rotation speed at each sliding portion is further reduced, so that local heat generation can be suppressed.

(Aspect 7)
Further, in the bearing mechanism according to the embodiment, a gear that rotates integrally is provided in the bearing portion of one or more stages, and the gear that rotates integrally has a larger diameter than the gear of the bearing portion held by the provided bearing portion. The diameter is smaller than the gear of the bearing portion that holds the provided bearing portion. Therefore, by making the diameter of the gear of each bearing larger than the diameter of the gear of the bearing that holds the diameter and smaller than the diameter of the gear of the bearing that is held, the relative rotation speed of the bearing is gradually reduced with respect to the rotation speed of the shaft. can do.

(Aspect 8)
Further, in the bearing mechanism according to the embodiment, the first gear and one stepped gear for driving the gear of the bearing member are provided. Therefore, by using one stepped gear as the drive gear, the number of parts is reduced, so that assembly is easy and the cost of parts can be reduced.

(Aspect 9)
Further, in the bearing member according to the embodiment, a spiral blade shape is provided on the outer periphery of the inner bearing portion. Therefore, when there is an outer periphery of the bearing in the transport path of the developer and the developer comes into contact with the bearing, it is possible to suppress the retention of the developer and the increase in the pressure of the developer by providing a stirring shape, and it is possible to prevent the developer from leaking from the bearing. ..

(Aspect 10)
Further, in the bearing member according to the embodiment, the material of at least one bearing portion is a slidable resin. Therefore, the slidability is improved and heat generation can be reduced.

(Aspect 11)
Further, in the bearing member according to the embodiment, the material of the inner bearing portion is polyacetal resin. Therefore, it is a slidable resin that is commonly used and is easily available.

(Aspect 12)
Further, in the bearing member according to the embodiment, the portion of the bearing portion that slides with the bearing portion that holds the bearing portion is made of metal. Therefore, since metal has higher heat dissipation than resin, the temperature rise is reduced.

(Aspect 13)
Further, in the bearing member according to the embodiment, the sliding portion is formed of a thin columnar metal portion, and a seal member is provided on the surface of the metal portion to seal between the bearing portion and the bearing portion holding the bearing portion. It is the one that was brought into contact. Therefore, since metal has higher heat dissipation than resin, the temperature rise is reduced.

(Aspect 14)
Further, in the bearing member according to the embodiment, at least one of the two sealing members has a sliding layer made of a fluorine material. Therefore, the slidability is improved and heat generation can be reduced. Since the sealing member can be made greaseless, there is no risk of agglomerating due to grease.

(Aspect 15)
Further, the developing apparatus according to the embodiment includes the bearing member or bearing mechanism according to any one of aspects 1 to 14. Therefore, by using it as a developer transporting member, toner aggregation around the bearing can be prevented.

(Aspect 16)
Further, the developing apparatus according to the embodiment is a developing apparatus having the bearing member and the rotating member according to the thirteenth aspect, and a portion in which a part of the cylindrical shape is missing from the tip of the thin cylindrical metal portion. The rotating member is provided coaxially with the cylinder and has a rotational force transmitting portion that fits with the missing portion and transmits the rotational force. Therefore, toner aggregation around the bearing can be prevented.

(Aspect 17)
Further, the image forming apparatus according to the embodiment includes the bearing member or the bearing mechanism according to any one of aspects 1 to 14. Therefore, it is possible to prevent toner aggregation by providing it on a rotating shaft such as a developing device or a toner replenishing device where the developer / toner may come into contact with each other. The same applies to the bearings of other powder transport members.

1: Printer 5Y: Developer 26: Paper feed unit 26a: Paper feed roller 27: Paper feed unit 27a: Paper feed roller 28: Resist roller pair 29: Paper discharge roller pair 30: Discharge stack unit 32: Toner container 33: Toner bottle 34: Container tip cover 41: Photoreceptor 42: Cleaning part 42a: Cleaning blade 44: Charging part 46: Image-making part 47: Exposure device 48: Intermediate transfer belt 49: Primary transfer roller 50: Development device 51: Development roller 52: Doctor blade 53: First developer accommodating unit 54: Second developer accommodating unit 55: Conveying screw 56: Toner concentration sensor 57: Toner replenishment port 60: Toner replenishment device 61: Replenishment pipe 62: Replenishment screw 63: Sub hopper 64: Toner drop transfer tube 66: Agitator 82: Secondary transfer backup roller 85: Intermediate transfer unit 86: Fixing device 89: Secondary transfer roller 91: Bottle side drive mechanism unit 92: Subhopper side drive mechanism unit 100: Transfer member 101 : Shaft 102: Screw blade 103: Transport path forming member 111: Toner amount detection sensor 120: Bearing member 130: Rotary bearing 130a: Rotary bearing 133: Stirring member shape portion 134: Stirring blade portion 135: Metal portion 136: Supported Part 140: Fixed bearing 151: First seal member 152: Second seal member 160: Drive gear 161: Drive gear 170: Shaft drive input gear 171: Bearing drive input gear 173: Stepped gear 173a: Diameter part 173b: Diameter part 174: Stepped gear 174a: Tooth part 174b: Tooth part 174c: Tooth part 174d: Tooth part 301: Container rotary gear 302: Spiral protrusion 605: Conveying screw gear 608: Set cover 611: Conveying nozzle 614: Conveying screw 700: ID chip 701: ID chip connector G: developer L: laser beam P: recording medium

Japanese Unexamined Patent Publication No. 2014-228666

Claims (17)

A bearing member for receiving the shaft
With the inner bearing
The outer bearing portion that rotatably holds the inner bearing portion, and the outer bearing portion.
A sealing member for sealing between the shaft and the inner bearing portion, and
A bearing member provided with a sealing member for sealing between the inner bearing portion and the outer bearing portion. In the bearing member according to claim 1,
The two sealing members are bearing members, characterized in that the rubbing portions are arranged so as to occur at different positions in the axial direction. In the bearing member according to claim 1 or 2.
Between the inner bearing portion and the outer bearing portion, one or more stages of bearing portions that rotatably hold the relatively inner bearing portion and are rotatably held by the relatively outer bearing portion. A bearing member characterized by having. In the bearing member of claim 3,
The bearing portion having one or more stages rotatably held by the relatively outer bearing portion is characterized in that the held portion is a cylindrical metal member and a resin member is provided inside the metal member. Bearing member. A bearing mechanism having a shaft provided with a first gear and a bearing member.
The bearing member is
With the inner bearing
The outer bearing portion that rotatably holds the inner bearing portion, and the outer bearing portion.
It has a second gear that rotates integrally with the inner bearing portion.
The bearing mechanism is characterized in that the first gear has a smaller diameter than the second gear. The bearing mechanism according to claim 5, or the bearing mechanism according to claim 5, wherein the bearing member according to claim 1 or 2 is used as the bearing member.
The bearing member is one step in which a relatively inner bearing portion is rotatably held between the inner bearing portion and the outer bearing portion, and the bearing member is rotatably held by the relatively outer bearing portion. A bearing mechanism characterized by having the above bearing portions. In the bearing mechanism according to claim 6,
A gear that rotates integrally is provided in the bearing portion of one or more stages.
The integrally rotating gear has a larger diameter than the gear of the bearing portion held by the provided bearing portion, and has a smaller diameter than the gear of the bearing portion holding the provided bearing portion. mechanism. In the bearing mechanism according to any one of claims 5 to 7.
A bearing mechanism provided with one stepped gear for driving the first gear and the gear of the bearing member. In the bearing member according to any one of claims 1 to 3.
A bearing member characterized in that a spiral blade shape is provided on the outer periphery of the inner bearing portion. In the bearing member according to any one of claims 1 to 3 and 9.
A bearing member characterized in that the material of at least one bearing portion is a slidable resin. The bearing member according to any one of claims 1 to 3, 9, and 10.
A bearing member characterized in that the material of the inner bearing portion is polyacetal resin. The bearing member according to any one of claims 1 to 3 and 9 to 11.
A bearing member characterized in that a portion of the bearing portion that slides with the bearing portion that holds the bearing portion is made of metal. In the bearing member according to claim 12,
The bearing member is characterized in that the sliding portion is formed of a thin columnar metal portion, and a sealing member for sealing between the surface of the metal portion and the bearing portion holding the bearing portion is brought into contact with the surface of the metal portion. .. The bearing member according to any one of claims 1 to 3 and 9 to 13.
A bearing member characterized in that at least one of the two sealing members has a sliding layer made of a fluorine material. A developing device provided with the bearing member or bearing mechanism according to any one of claims 1 to 14. A developing apparatus having the bearing member and the rotating member according to claim 13.
The tip of the thin cylindrical metal portion has a portion in which a part of the cylindrical shape is missing.
The developing device is characterized in that the rotating member is provided coaxially with the cylinder and has a rotational force transmitting portion that fits with the missing portion and transmits the rotational force. An image forming apparatus comprising the bearing member or bearing mechanism according to any one of claims 1 to 14.

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