JP5850305B2 - Planetary gear drive transmission device and image forming apparatus - Google Patents

Description

  The present invention relates to a planetary gear drive transmission device that transmits a rotational drive force from a drive source to a rotational speed required by a drive target, and an image forming apparatus including the planetary gear drive transmission device.

  In image forming apparatuses such as electrophotographic copying machines, printers, facsimiles, and multifunction machines, an electrostatic latent image is formed on the surface of a photosensitive drum or the like that is a rotating cylindrical latent image carrier, and the electrostatic 2. Description of the Related Art Image forming apparatuses that perform development by attaching toner to a latent image are known. In such an image forming apparatus, the toner image obtained by development is primarily transferred onto an intermediate transfer belt or the like which is an endless belt body, and further transferred onto a surface of a sheet or the like as a recording material, Thereafter, the image is fixed and an image is formed on the surface of a recording paper or the like.

  Further, in such an image forming apparatus, many rotating bodies are used such as a photosensitive drum, a driving roller for driving a belt member such as an intermediate transfer belt and a transfer conveyance belt, and a conveyance roller for conveying a sheet or the like. Has been. In general, high precision is required for driving such a rotating body. Therefore, a mechanism for transmitting the rotational driving force from the driving source to the rotating body to be driven in a state where the rotational fluctuation is small is desired. In particular, when speed fluctuations occur in the surface moving speed of a photosensitive drum, an intermediate transfer belt, or the like, jitter and density unevenness occur on the output image.

  Specifically, if the speed fluctuation continues at a certain frequency on the photosensitive drum or the intermediate transfer belt, periodic density unevenness occurs in the entire image, which is visually observed as banding of a striped pattern. In addition, the speed fluctuation of the photosensitive drum may cause a sub-scanning position shift of the writing system exposure line or a sub-scanning position shift during the primary transfer of the toner image from the photosensitive drum to the intermediate transfer belt. To do. On the other hand, the speed fluctuation of the intermediate transfer belt causes a sub-scanning position shift between the primary transfer and the secondary transfer. Then, banding due to such speed fluctuations causes a significant reduction in image quality.

  In such a drive transmission device for a photosensitive drum or an intermediate transfer belt that requires high-precision driving, a reduction mechanism that can transmit a rotational driving force from a high-rotation driving source at a high reduction ratio in order to suppress speed fluctuations. Is often used. On the other hand, downsizing of an image forming apparatus has been demanded conventionally, and a planetary gear speed reduction mechanism and a traction method (friction transmission method) that can be downsized compared to a speed reduction mechanism using a large-diameter gear of a general external gear. An image forming apparatus using a planetary speed reduction mechanism is widely used.

  For example, Patent Document 1 describes an image forming apparatus using a traction type planetary deceleration mechanism as follows. In an image forming apparatus including a plurality of photosensitive drums and capable of forming a full-color image, a traction type planetary reduction mechanism is used as a drive transmission device that transmits a rotational driving force from a driving source to each photosensitive drum. An image forming apparatus. In this image forming apparatus, a photosensitive drum shaft is inserted into a planetary reduction mechanism while being rotatably supported by a ball bearing, and is configured integrally with an output shaft of the planetary reduction mechanism. By integrally configuring the photosensitive drum shaft and the output shaft of the planetary reduction mechanism, it is possible to eliminate errors in the coaxiality and straightness between the photosensitive drum shaft, which is the rotating shaft of the rotated body, and the output shaft of the carrier. . That is, it is possible to eliminate the cause of fluctuations in the rotational speed of the rotated body when the rotating shaft of the rotated body and the output shaft of the planetary reduction mechanism are provided separately.

  However, in the configuration using the traction type planetary reduction mechanism described in Patent Document 1, it is necessary to increase the accuracy of each part and the assembly accuracy to the micron order, and the manufacturing cost increases. It is not suitable for mass production. Furthermore, in order to drive a plurality of photosensitive drums, a motor or the like that is a driving source and a planetary speed reducer that is a drive transmission device are required for each photosensitive drum, and further downsizing is difficult and expensive. There was a problem that it would become a simple device. This problem is not limited to the configuration using a traction type planetary speed reduction mechanism in the drive transmission device as in Patent Document 1, and uses a low-cost planetary gear speed reduction mechanism as compared with a traction type planetary speed reduction mechanism. There was a similar problem with the configuration.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a planetary gear drive transmission device that is smaller and less expensive than a conventional configuration in which a driving source and a planetary gear mechanism are provided for each rotating body. It is to be.

In order to achieve the above object, according to a first aspect of the present invention, there is provided a planetary gear drive transmission device that transmits a rotational driving force of a driving source to a rotating body through a planetary gear mechanism. The first stage planetary gear mechanism to which the rotational driving force of the driving source is directly input, and the rotational driving force output from the output shaft of the first stage planetary gear mechanism. And a plurality of second-stage planetary gear mechanisms that transmit to corresponding rotating bodies, respectively, and two large and small external gears are provided on the output shaft of the first-stage planetary gear mechanism. The toothed gear transmits a rotational driving force output from the output shaft of the first stage planetary gear mechanism to a first rotating body provided coaxially with the output shaft of the first stage planetary gear mechanism. A first second stage sun gear serving as an input shaft of the second stage planetary gear mechanism. The large external gear is integrated and coaxial with the second second-stage sun gear serving as the input shaft of the second second-stage planetary gear mechanism corresponding to the second rotor adjacent to the first rotor. the first intermediate gear der is, the first two stages to transmit the rotational driving force output from the output shaft of the first-stage planetary gear mechanism meshes with the second intermediate gear is an external gear provided on the The component of the output shaft of the first planetary gear mechanism is different from the component of the output shaft of the second second-stage planetary gear mechanism .
In the present invention, the rotational driving force output from the output shaft of the first-stage planetary gear mechanism to which the rotational driving force of the driving source is directly input is supplied to the first-stage planetary gear via the first second-stage planetary gear mechanism. It can be transmitted to the first rotating body provided coaxially with the output shaft of the mechanism. Moreover, it can transmit to the 2nd rotary body adjacent to a 1st rotary body via the 2nd 2nd stage planetary gear mechanism corresponding to a 2nd rotary body. That is, the rotational driving force output from the output shaft of the first stage planetary gear mechanism to which the rotational driving force of one driving source is directly input is transmitted to the corresponding rotating body by the plurality of second stage planetary gear mechanisms. it can. Therefore, it is not necessary to provide a driving source and a planetary gear mechanism independently for each rotating body. Therefore, the number of drive sources can be reduced and the installation space for the planetary gear mechanism can be reduced as compared with the conventional configuration in which the drive source and the planetary gear mechanism are provided independently for each rotating body.

In the present invention, the number of drive sources can be reduced and the installation space for the planetary gear mechanism can be reduced as compared with the conventional configuration in which the drive source and the planetary gear mechanism are provided independently for each rotating body. it can.
Therefore, it is possible to provide a planetary gear drive transmission device that is small and low-cost as compared with a conventional configuration in which a driving source and a planetary gear mechanism are provided independently for each rotating body.

1 is a schematic configuration diagram of a copier according to an embodiment. 1 is an explanatory diagram of a planetary gear drive transmission device according to Embodiment 1. FIG. Explanatory drawing of the single drive part which drives independently the photosensitive drum corresponding to black. Cross-sectional explanatory drawing of the 1st step | paragraph carrier of the planetary gear reduction mechanism provided in the independent drive part. Cross-sectional explanatory drawing of the 2nd step | paragraph carrier of the planetary gear reduction mechanism provided in the independent drive part. The perspective explanatory drawing of the 1st step | paragraph carrier of the planetary gear reduction mechanism provided in the independent drive part. The perspective explanatory drawing of the 2nd step | paragraph carrier of the planetary gear reduction mechanism provided in the independent drive part. Explanatory drawing of the aspect of a connection with a photoconductor drum and a planetary gear drive transmission device. Explanatory drawing of the drive source shared part in the planetary gear drive transmission apparatus of Example 2. FIG. Explanatory drawing of the drive source shared part in the planetary gear drive transmission apparatus of Example 3. FIG.

  Hereinafter, an embodiment in which the present invention is applied to an electrophotographic color copying machine (hereinafter referred to as a copying machine 500) as an image forming apparatus will be described with reference to the drawings. First, an outline of the copier 500 of the present embodiment common to the respective examples will be described. Here, FIG. 1 is a schematic configuration diagram of the copying machine according to the present embodiment.

  In FIG. 1, reference numeral 100 denotes a copying machine main body, reference numeral 200 denotes a paper feed table on which the copying machine is placed, reference numeral 300 denotes a scanner mounted on the copying machine main body 100, and reference numeral 400 further denotes an automatic document transport mounted thereon. Device (ADF). This copier is a tandem type electrophotographic copier that employs an intermediate transfer (indirect transfer) system.

  In the center of the copying machine main body 100, an intermediate transfer belt 10 including a belt which is an intermediate transfer member serving as an image carrier is provided. The intermediate transfer belt 10 is stretched around a first support roller 14, a second support roller 15, and a third support roller 16 as three support rotating bodies, and rotates and moves in the clockwise direction in the figure. On the left side of the second support roller 15 in the figure, an intermediate transfer belt cleaning device 17 for removing residual toner remaining on the intermediate transfer belt 10 after image transfer is provided. Further, a belt portion stretched between the first support roller 14 and the second support roller 15 has a yellow (Y), magenta (M), cyan (C), black ( A tandem image forming unit 20 in which the four image forming units 18 of K) are arranged side by side is arranged oppositely. In the present embodiment, the third support roller 16 is a drive roller. An exposure device 21 as a latent image forming unit is provided above the tandem image forming unit 20.

  A secondary transfer device 22 as a second transfer unit is provided on the opposite side of the tandem image forming unit 20 with the intermediate transfer belt 10 interposed therebetween. In the secondary transfer device 22, a secondary transfer belt 24, which is a belt as a recording material conveying member, is stretched between a roller 23a and a roller 23b. The secondary transfer belt 24 is provided so as to be pressed against the third support roller 16 via the intermediate transfer belt 10. The secondary transfer device 22 transfers the toner image on the intermediate transfer belt 10 to a sheet as a recording material. A fixing device 25 for fixing the toner image transferred on the sheet is provided on the left side of the secondary transfer device 22 in the drawing. The fixing device 25 has a configuration in which a pressure roller 27 is pressed against a fixing belt 26 that is a belt member. The secondary transfer device 22 described above also has a sheet transport function for transporting the sheet after the toner image transfer to the fixing device 25. Of course, a transfer roller or a non-contact charger may be disposed as the secondary transfer device 22, and in such a case, it is difficult to provide this sheet conveying function together. In the present embodiment, a sheet reversing device for reversing the sheet so as to record an image on both sides of the sheet is provided below the secondary transfer device 22 and the fixing device 25 in parallel with the tandem image forming unit 20 described above. 28 is also provided.

  When making a copy using the copying machine 500, a document is set on the document table 30 of the automatic document feeder 400. Alternatively, the automatic document feeder 400 is opened, a document is set on the contact glass 32 of the scanner 300, and the automatic document feeder 400 is closed and pressed by it. Thereafter, when a start switch (not shown) is pressed, when the document is set on the automatic document feeder 400, the document is conveyed and moved onto the contact glass 32. On the other hand, when an original is set on the contact glass 32, the scanner 300 is immediately driven. Next, the first traveling body 33 and the second traveling body 34 travel. Then, the first traveling body 33 emits light from the light source and further reflects the reflected light from the document surface toward the second traveling body 34, and is reflected by the mirror of the first traveling body 34 and passes through the imaging lens 35. The document is placed in the reading sensor 36 and the original content is read.

  In parallel with this document reading, a third support roller 16 as a drive roller is rotationally driven by an intermediate transfer belt drive motor as a drive source (not shown). As a result, the intermediate transfer belt 10 moves in the clockwise direction in the drawing, and the first support roller 14 and the second support roller 15 rotate along with the movement. At the same time, the photosensitive drums 40Y, 40M, 40C, and 40K as the latent image carriers are rotated in the individual image forming units 18Y, 18M, 18C, and 18K, and the photosensitive drums 40Y, 40M, 40C, and 40K are rotated. On top of this, exposure and development are respectively performed using information for each color of yellow, magenta, cyan, and black to form a single color toner image (developed image). Then, the toner images on the photosensitive drums 40Y, 40M, 40C, and 40K are sequentially transferred onto the intermediate transfer belt 10 so as to overlap each other, thereby forming a composite color image on the intermediate transfer belt 10.

  In parallel with such image formation, one of the paper feed rollers 42 of the paper feed table 200 is selectively rotated, and the sheet is fed out from one of the paper feed cassettes 44 provided in the paper bank 43 in multiple stages. The sheets are separated one by one and placed in the paper feed path 46, transported by the transport roller 47, guided to the paper feed path in the copying machine main body 100, and abutted against the registration roller 49 and stopped. Alternatively, the manual feed roller 50 is rotated to feed out the sheets on the manual feed tray 51, separated one by one by the separation roller 52, put into the manual feed path 53, and abutted against the registration roller 49 and stopped. Then, the registration roller 49 is rotated in synchronization with the composite color image on the intermediate transfer belt 10, the sheet is fed between the intermediate transfer belt 10 and the secondary transfer device 22, and transferred by the secondary transfer device 22. A color image is transferred onto the sheet. The image-transferred sheet is conveyed by the secondary transfer belt 24 and sent to the fixing device 25. The fixing device 25 applies heat and pressure to fix the transferred image, and then the switching roller 55 is switched to the discharge roller 56. Are discharged and stacked on the discharge tray 57. Alternatively, it is switched by the switching claw 55 and put into the sheet reversing device 28, where it is reversed and guided again to the transfer position, an image is recorded also on the back side of the sheet, and then discharged onto the discharge tray 57 by the discharge roller 56. .

  The intermediate transfer belt 10 after the image transfer is removed by the intermediate transfer belt cleaning device 17 to remove residual toner remaining on the intermediate transfer belt 10 after the image transfer, so that the tandem image forming unit 20 can prepare for another image formation. Here, the registration roller 49 is generally used while being grounded, but it is also possible to apply a bias for removing paper dust from the sheet.

  This copier can be used to make a black and white copy. In that case, the intermediate transfer belt 10 is separated from the photosensitive drums 40Y, 40M, and 40C by means not shown. These photosensitive drums 40Y, 40M, and 40C are temporarily stopped from driving. Only the black photosensitive drum 40K is brought into contact with the intermediate transfer belt 10 to perform image formation and transfer.

  Next, a plurality of examples are given for the planetary gear drive transmission device 110 that decelerates and transmits the rotational driving force of the drive source to each of the photosensitive drums 40Y, 40M, 40C, and 40K, which is a characteristic part of the present embodiment. explain.

Example 1
First, description will be made with reference to the drawings from Example 1 which is a first example of the present embodiment. Here, FIG. 2 is an explanatory diagram of the planetary gear drive transmission device 110 of this embodiment, and FIG. 3 is an explanatory diagram of the single drive unit 111 that independently drives the photosensitive drum 40K corresponding to black. 4 is a cross-sectional explanatory view of the first carrier 124 of the first stage of the planetary gear speed reduction mechanism 120 provided in the single drive section 111, and FIG. 5 is a second stage of the planetary gear speed reduction mechanism 120 provided in the single drive section 111. FIG. 10 is a cross-sectional explanatory view of the second carrier 127 of FIG. 6 is a perspective explanatory view of the first carrier 124 of the first stage of the planetary gear speed reduction mechanism 120 provided in the single drive section 111, and FIG. 7 is a second stage of the planetary gear speed reduction mechanism 120 provided in the single drive section 111. It is a perspective explanatory view of the 2nd career 127 of. FIG. 8 is an explanatory diagram of a connection mode between the photosensitive drum 40K and the planetary gear reduction mechanism 120. FIG.

  As shown in FIG. 2, two photoconductor drive motors 105 and 106 are connected to the planetary gear drive transmission device 110 of this embodiment. Then, a single drive unit 111 that independently drives the photosensitive drum 40K to rotate by the photosensitive member drive motor 105, and a drive source shared unit that drives the other photosensitive drums 40Y, 40M, and 40C to rotate by the same photosensitive member drive motor 106. 112 is provided. In the single drive unit 111, the rotational driving force of the photoconductor drive motor 105 is transmitted to the photoconductor drum 40K used for monochrome image formation that is frequently used via the planetary gear speed reduction mechanism 120 having a 2KH type two-stage configuration. Further, as will be described in detail later, in the drive source sharing unit 112, planetary gears in which the rotational driving force of the photosensitive member driving motor 106 is provided in one for the first stage and three for the respective photosensitive bodies in the second stage. This is transmitted to the photosensitive drums 40Y, 40M, and 40C used for color image formation via the speed reduction mechanism.

  First, the single drive unit 111 will be described. As described above, in the single drive unit 111, the planetary gear speed reduction mechanism 120 that transmits the rotational driving force of the photosensitive member driving motor 105 to the photosensitive drum 40K has a 2KH type two-stage configuration. As shown in FIG. 3, a first sun gear 121 serving as an input shaft of the planetary gear reduction mechanism 120 is integrally formed on the motor output shaft 107 of the photosensitive member driving motor 105. The first planetary gear 123, which is the first stage planetary gear meshing with the first sun gear 121 and the internal gear 122 fixed to the motor bracket 130, is supported by the first carrier 124, which is the first stage carrier. The outer periphery of one sun gear 121 is revolved. In addition, the first planetary gear 123 has a plurality of three or more concentrically arranged for rotational balance and torque sharing. In the present embodiment, as shown in FIG. 4, the first planetary gears 123 are arranged at positions that are equally divided into three in the circumferential direction. The first planetary gear 123 rotates and revolves due to the engagement of the first sun gear 121 and the internal gear 122, and the first carrier 124 that supports the first planetary gear 123 rotates the first sun gear 121. In contrast, the vehicle rotates at a reduced speed to obtain the first stage reduction ratio.

  Next, a second sun gear 125, which is a second stage sun gear provided at the rotation center of the first carrier 124, serves as an input to the second stage reduction mechanism. Here, the first carrier 124 does not have a rotation support portion and performs floating rotation. In the second sun gear 125, a second planetary gear 126, which is a second-stage planetary gear meshing with the internal gear 122 formed integrally up to the second stage, is supported by a second carrier 127, which is a second-stage carrier. Thus, the outer periphery of the second sun gear 125 is revolved. In the present embodiment, as shown in FIG. 5, the number of second planetary gears 126 is such that the second planetary gears 126 are arranged at positions that are equally divided into four in the circumferential direction. The second carrier 127 corresponding to the final stage is provided with an output shaft 128, and a spline-like internal tooth shape is formed on the inner surface of the cylindrical shaft. On the other hand, the drum shaft 41K connected to the photosensitive drum 40K has a spline-shaped external tooth shape so as to mesh with the spline-shaped internal teeth on the inner surface of the cylindrical shaft of the output shaft 128, and is used as an input unit. A spline portion is provided.

  Here, one unit used in a general 2KH type planetary gear mechanism includes a sun gear, a planetary gear, a planetary carrier that supports the revolving motion of the planetary gear, and an internal tooth. It consists of four parts of the outer gear. Of the three elements that are the rotation of the sun gear, the revolution of the planetary gear (rotation of the carrier), and the rotation of the internal gear, one is fixed, one is input, and one is connected to the output. Depending on which one is assigned to input / output / fixed, multiple reduction ratios and rotation directions can be switched with one unit. The two-stage configuration of the 2KH type that is a target in this embodiment is classified as a compound planetary gear mechanism (two or more 2KH types), and there are two or more 2KH types, each of which is one element out of three elements. This is a mechanism that couples each other, fixes the remaining one by one, and uses the remaining two as an input shaft or output shaft. The type that fixes the internal gear is called a planetary type, and the rotation direction of the input shaft and the output shaft is the same direction with the sun gear as the input shaft and the carrier as the output shaft.

Regarding the reduction gear ratio, when the number of teeth of the sun gear is Za, the number of teeth of the planetary gear is Zb, and the number of teeth of the internal gear is Zc, the planetary type one-stage planetary gear mechanism is expressed by the following formula 1. . Here, the subscripts 1 and 2 in the formula mean the first and second stages.
Planetary type:
Reduction ratio = Za1 / (Za1 + Zc1) (Formula 1)
The type that fixes the carrier is called a star type, and the rotation direction of the input shaft and the output shaft is opposite to each other with the sun gear as the input shaft and the internal gear as the output shaft. The star type reduction ratio is expressed by the following formula 2.
Star type:
Reduction ratio = Za1 / Zc1 (Formula 2)
As described above, the planetary type has a larger reduction ratio.

The reduction gear ratio of the two-stage planetary gear mechanism is the product of the first reduction gear ratio and the second reduction gear ratio. In the two-stage planetary gear speed reduction mechanism 120 of the present embodiment shown in FIG. 3, since the first stage and the second stage are both planetary type, the reduction ratio is expressed by the following Equation 3.
Reduction ratio = Za1 / (Za1 + Zc1) × Za2 / (Za2 + Zc2) (Equation 3)

  The motor output shaft 107 of the photosensitive member driving motor 105 described above is supported by a motor fixing flange 132 via two bearings (not shown). By supporting the motor output shaft 107 of the photosensitive member driving motor 105, the outer rotor that is the rotor of the DC brushless motor is supported. On the motor fixing flange 132, a stator core (not shown) of the photosensitive member driving motor 105, a motor driving circuit board 131, and the like are also installed. Further, a first sun gear 121 is integrally formed on the motor output shaft 107 of the photosensitive member driving motor 105 by gear cutting. And in order to ensure the coaxial precision with the axis | shaft of the 1st sun gear 121 and the axis | shaft of the internal gear 122, the internal gear 122 and the motor fixing flange 132 are positioned by the fitting by an inlay. Further, the motor fixing flange 132 is positioned by fitting with the motor bracket 130 by an inlay.

  An end cap 129 is fixed to the end of the internal gear 122 opposite to the motor fixing flange 132. In the end cap 129, when the planetary gear speed reduction mechanism 120 is assembled to the motor bracket 130, the planetary gears, the carriers, and the output shaft 128 installed in the internal gear 122 are detached from the internal gear 122. It is used as a member for preventing this. The output shaft 128 provided on the end cap 129 and the second carrier 127 has a sufficient clearance so that the end cap 129 does not support the rotation of the second carrier 127 and the second carrier 127 performs floating rotation. It has become.

  The planetary type carrier shape of this embodiment will be described with reference to FIGS. In this embodiment, as shown in FIGS. 6 and 7, a carrier having both shafts is used. Generally, a radial load for rotating the carrier is generated on the carrier pin. For this reason, the carrier having a cantilever structure is likely to cause the carrier pin to be inclined, and the rotation transmission accuracy is deteriorated. On the other hand, the dual-support carrier structure has an advantage that the carrier pin is hardly inclined. In particular, when the carrier material is resin, high rigidity is remarkable by adopting a dual shaft support structure. In addition, molding the carrier with resin enables mass production at low cost by injection molding.

  First, the first carrier 124 that is the first stage carrier will be described in detail. As shown in FIG. 5, the first carrier 124 is configured to support both end portions of the first carrier pin 124d that supports the first planetary gear 123 by two side plates, a first carrier side plate 124a and a first carrier side plate 124b. It is. Three first planetary gears 123 are arranged on the first carrier 124, and the first carrier side plate 124a and the first carrier side plate 124b are fixed by three first carrier columns 124c. The revolution rotation of the first planetary gear 123 becomes the rotation of the entire first carrier 124, and the rotation is transmitted to the second sun gear 125 integrally formed on the same axis as the first carrier side plate 124 a. The second carrier 127, which is the second stage carrier, will be described in detail. As shown in FIG. 7, the second carrier 127 has the same configuration as the first carrier 124, but the number of the second planetary gear 126 and the second carrier struts 127c is four. Further, the output shaft 128 integrally formed on the same axis as the second carrier side plate 127a of the second carrier 127 has a spline-like internal tooth shape on the inner surface of the cylindrical shaft.

  Next, a configuration for detachably supporting the photosensitive drums of this embodiment will be described with reference to FIG. Here, the drum shafts 41Y, 41M, 41C, and 41K of the photosensitive drums 40Y, 40M, 40C, and 40K are rotationally driven by the second-stage output shafts 165M, 175Y, 175C, and the output shaft 128K having substantially the same configuration. Hereinafter, the photosensitive drum 40K and the planetary gear speed reduction mechanism 120 will be described. Although not explained, the present invention can also be applied to a driving roller of the intermediate transfer belt 10.

  First, the configuration of the photosensitive drum unit 140K will be described. A rear drum flange 143K and a front drum flange 142K are fixed to the end of the photosensitive drum 40K in the axial direction, and each drum flange is supported by the drum shaft 41K. The rear drum flange 143K is connected to the drum shaft 41K by a serration coupling, and when the drum shaft 41K rotates, the photosensitive drum 40K rotates in synchronization. The serration coupling has a male shape on the drum shaft 41K side, a female shape on the rear drum flange 143K side, and is tapered from the front side of the drum shaft 41K. In the unit case 141K that supports the photosensitive drum 40K, the photosensitive drum 40K, a charger 2K, a developing device 9K, a cleaning device 4K, a static elimination lamp, and the like (not shown) are accommodated. The rear side (right side in FIG. 8) of the unit case 141K is supported by a bearing fixed to the drum shaft 41K, and the rear drum flange 143K is also supported by the bearing, so that the photosensitive drum 40K and the unit case are supported. 141K is located. Further, on the front side (left side in FIG. 8), the boss portion of the front drum flange 142K is fitted with the unit case 141K and is rotatable. The drum shaft 41K is further provided with another bearing at a portion where the drum shaft 41K is fitted to the main body rear side plate 191, and is positioned with the main body rear side plate 191.

  The main body front side plate 190 is provided with a notch for attaching and detaching the photosensitive drum unit 140K, and a face plate 144K is fixed thereto. The front end of the drum shaft 41K is rotatably supported by the face plate 144K via a bearing. The photosensitive drum unit 140K can be attached and detached by removing the face plate 144K. When the photosensitive drum unit 140K is mounted, the photosensitive drum 40K is pressurized in the drum axial direction by the pressure spring 145K provided between the bearing fixed to the face plate 144K and the boss portion of the front drum flange 142K. Then, the rotational direction and the thrust direction are positioned by the tapered serration coupling portion. In the photosensitive drum unit 140K, the two positioning pins 146K provided on the rear side of the unit case 141K are fitted into the holes in the rear plate of the main body, and the position in the rotation direction is determined.

  Next, attachment of the planetary gear reduction mechanism 120 in the single drive unit 111 will be described. A motor bracket 130 is attached to the main body rear side plate 191 via a stud 133. A motor fixing flange 132 that supports the planetary gear speed reduction mechanism 120 is fixed to the motor bracket 130 and assembled. The planetary gear reduction mechanism 120 is positioned by fitting the internal gear 122 into a hole provided in the motor fixing flange 132. Further, the planetary gear speed reduction mechanism 120 may be attached so that the motor bracket 130 also serves as the motor fixing flange 132. As described above, the planetary gear speed reduction mechanism 120 is attached to the motor bracket 130, so that the output side of the internal gear 122 is free to be easily deformed. By mounting in this way, the planetary gear speed reduction mechanism 120 and the photoconductor drive motor 105 are independently arranged and rotated with respect to one photoconductor drum 40K.

  Here, as shown in FIG. 2, the planetary gear drive transmission device 110 of this embodiment has a four-tandem tandem configuration including the photosensitive drums 40Y, 40M, 40C, and 40K. As described with reference to FIG. 8, the photosensitive drum 40 </ b> K corresponding to black (K) has a planetary gear speed reduction mechanism 120 and a photosensitive member driving motor 105 arranged independently of the other colors and driven independently. Part 111 is configured. Black is frequently used as a single color. By stopping and using other colors, unnecessary rotation of other colors is eliminated, and the life of the photosensitive drums 40Y, 40M, and 40C of other colors is maintained long. Can do. Next, the configuration of the drive source sharing unit 112 that rotationally drives the photosensitive drums 40Y, 40M, and 40C of the other colors by the single photosensitive member driving motor 106 will be described.

  As shown in FIG. 2, in the driving source sharing unit 112 of this embodiment, the photosensitive member driving motor 106 is arranged on the same axis as the three photosensitive drums arranged in the middle, that is, the photosensitive drum 40M as the first rotating body. Provided. The photosensitive member driving motor 106 is fixed to the motor bracket 140 together with the first-stage internal gear 152 that is the internal gear of the first-stage planetary gear reduction mechanism 150 that is the first-stage planetary gear reduction mechanism 150 with a coaxial accuracy. Yes. The motor bracket 180 is supported and fixed to the driving side plate 184 via the stud 183. The driving side plate 184 is supported and fixed to the main body rear side plate 191 via a sudad 185. A first-stage sun gear 151 that is a first-stage sun gear directly geared to the motor output shaft 108 of the photoconductor drive motor 106 is connected to a first-stage carrier pin 154 that is a first-stage carrier. The first stage planetary gear 153 meshes with the fixed first stage internal gear 152 and meshes with the three first stage planetary gears 153 rotatably supported via 154d.

  When the input first stage sun gear 151 rotates, the first stage planetary gear 153 rotates along the first stage sun gear 151 and the first stage internal gear 152 while rotating. The revolution becomes the rotation of the first-stage carrier 154 supporting the first-stage planetary gear 153 and the first-stage output rotation. In the present embodiment, the first stage carrier 154 is configured integrally with the first intermediate gear 156M, and is a first stage planetary gear mechanism that is disposed coaxially with the first stage carrier 154. The second stage sun gear 161M, which is an input to the stage planetary gear mechanism 160M, is also configured integrally. The first intermediate gear 156M has a larger diameter than the first-stage internal gear 152, and a second-stage sun gear 161M is provided coaxially with a boss portion on the same axis. The first intermediate gear 156M is rotatably supported on the driving side plate 184 by a boss portion via a bearing. The bearing is a sliding bearing and is provided with a certain clearance from the boss portion.

  The second-stage sun gear 161M meshes with four second-stage planetary gears 163M disposed around the second-stage sun gear 161M. The second stage planetary gear 163M is rotatably supported by a fixed second stage carrier pin 164dM and rotates only by the rotation of the second stage sun gear 161M. The second-stage carrier pin 164dM is fixedly supported by the driving side plate 184. A second-stage internal gear 162M is disposed outside the four second-stage planetary gears 163M, and rotates in mesh with the second-stage planetary gear 163M. The second-stage internal gear 162M is provided with a second-stage output shaft 165M that is a second-stage output shaft that forms a spline joint portion on the same axis. In the present embodiment, a spline-like internal tooth shape is formed on the inner surface of the cylindrical shaft of the second-stage output shaft 165M. An external tooth shape provided on the drum shaft 41M of the photosensitive drum 40M is inserted into and meshed with this internal tooth shape, and the rotation of the second-stage internal gear 162M is driven and transmitted to the drum shaft 41M. Rotation drive. Here, the drum shaft 41M is rotatably supported by the main body rear side plate 191 via a ball bearing.

  Next, drive transmission to the photosensitive drums 40Y and 40C adjacent to the photosensitive drum 40M will be described. The first intermediate gear 156M is engaged with a second intermediate gear 157Y, which is a second intermediate gear, and a second intermediate gear 157C. Here, since the second second-stage planetary gear mechanisms 170Y and 170C, which are the second second-stage planetary gear mechanisms, have the same configuration, the second second-stage planetary gear mechanism 170Y will be described. The second intermediate gear 157Y has substantially the same configuration as the first intermediate gear 156M, and the first stage carrier pin is not provided and the number of teeth is different. The second intermediate gear 156Y is also coaxially provided with a second stage sun gear 171Y with one boss portion on the same axis. The second intermediate gear 157Y is rotatably supported on the driving side plate 184 by a boss portion via a bearing. The bearing is a sliding bearing and is provided with a certain clearance from the boss portion.

  The second-stage sun gear 171Y meshes with four second-stage planetary gears 173Y arranged around the second-stage sun gear 171Y. The second stage planetary gear 173Y is rotatably supported by a second stage carrier pin 174dY fixed to the second stage carrier 174Y, and meshes with the outer second stage internal gear 172Y. The rotation of the second intermediate gear 157Y transmitted from the first intermediate gear 156M, that is, the rotation of the second-stage sun gear 171Y rotates along with the rotation of the second-stage planetary gear 173Y, and the rotation is the second-stage carrier 174Y. Is output as a rotation of. A second-stage end cap 179Y is fitted into the second-stage internal gear 172Y fixed to the driving side plate 184, and a second-stage output that constitutes a spline joint provided coaxially with the second-stage carrier 174Y. The shaft 175Y is rotatably supported. Further, the second-stage output shaft 175Y and the second-stage end cap 179Y have a clearance fit. A spline-like internal tooth shape is formed on the inner surface of the cylindrical shaft of the second-stage output shaft 175Y provided integrally with the second-stage carrier 174Y. An external tooth shape provided on the drum shaft 41Y of the photoconductive drum 40Y is inserted into and meshed with this internal gear shape, and the rotation of the second-stage carrier 174Y is transmitted to the drum shaft 41Y to drive the photoconductive drum 40Y. To do. Here, the drum shaft 41Y is rotatably supported on the main body rear side plate 191 via a ball bearing.

  As described above, in the drive source sharing unit 112 of the planetary gear drive transmission device 110 of the present embodiment, the first-stage carrier 154 is used as the output shaft of the first-stage planetary gear reduction mechanism 150 connected to the photoconductor drive motor 106. Are provided with two large and small external gears. The small-side external gear is a second-stage sun gear 161M serving as an input shaft of the first second-stage planetary gear mechanism 160M, and the large-side external gear is a first intermediate gear 156M. The first intermediate gear 156M is integrated with the second-stage sun gears 171Y, 171C serving as the input shafts of the second second-stage planetary gear mechanisms 170Y, C respectively corresponding to the photosensitive drums 40Y, 40C adjacent to the photosensitive drum 40M. In addition, the rotational driving force output from the first stage planetary gear reduction mechanism 150 can be transmitted by meshing with the second intermediate gears 157Y, C provided on the same axis. That is, the rotational driving force output from the first stage planetary gear reduction mechanism 150 is converted into the second stage sun gear which is also the output shaft of the first stage planetary gear reduction mechanism 150 via the first second stage planetary gear reduction mechanism 160M. It can be transmitted to a photosensitive drum 40M provided coaxially with 161M. Further, it can be transmitted to the photosensitive drums 40Y and 40C adjacent to the photosensitive drum 40M via the second second stage planetary gear mechanisms 170Y and C corresponding to the photosensitive drums 40Y and 40C.

  That is, the rotational driving force output from the output shaft of the first stage planetary gear reduction mechanism 150 to which the rotational driving force of one photoconductor driving motor 106 is directly input is used as the first second stage planetary gear mechanism 160M and the first planetary gear mechanism 160M. Two second-stage planetary gear mechanisms 170Y and 170C can transmit to the corresponding photosensitive drums 40Y, 40M and 40C, respectively. Since transmission is possible in this manner, it is not necessary to provide a photosensitive member drive motor and a planetary gear reduction mechanism independently for each of the three photosensitive drums. Therefore, the number of photosensitive member drive motors can be reduced and the installation space for the planetary gear reduction mechanism can be reduced as compared with a conventional configuration in which a photosensitive member drive motor and a planetary gear reduction mechanism are provided independently for each photosensitive drum. Can do. Therefore, it is possible to provide a planetary gear drive transmission device 110 that is small and low in cost as compared with a conventional configuration in which a photosensitive member drive motor and a planetary gear reduction mechanism are provided independently for each photosensitive drum.

  Further, the rotation directions of the photosensitive drum 40M and the photosensitive drum 40Y are simplified by directly engaging the intermediate gears without using the idler gears, thereby reducing the number of components. If the gear reduction mechanism has the same configuration, the direction is reversed. Therefore, in this embodiment, the constituent elements of the second-stage output shaft 165M of the first second-stage planetary gear mechanism 160M provided coaxially with the photosensitive member drive motor 106, and the adjacent second-stage planetary gear. The components of the second-stage output shafts 175Y and 175C of the mechanisms 170Y and C are made different so as to align the rotation direction. Specifically, in the first second-stage planetary gear mechanism 160M, the second-stage output shaft 165M is provided integrally with the second-stage internal gear 162M, and the second second-stage planetary gear mechanism 170Y, C The second-stage output shafts 175Y and 175C are integrally provided on the second-stage carriers 174Y and 174C, respectively. In this way, the components of the second-stage output shaft 165M of the first second-stage planetary gear mechanism 160M and the components of the second-stage output shafts 175Y, C of the second second-stage planetary gear mechanism 170Y, C Therefore, the photosensitive drums 40Y, 40M, and 40C can be rotationally driven in the same direction with a simplified configuration with fewer components.

  In the present embodiment, the second-stage sun gear 161M and the first intermediate gear 156M, which are the output shafts of the first-stage planetary gear reduction mechanism 150, are the first-stage carrier 154 that the first-stage planetary gear reduction mechanism 150 rotates. It is connected to the. The second-stage output shaft 165M of the first second-stage planetary gear mechanism 160M is connected to the second-stage internal gear 162M that is rotated by the first second-stage planetary gear mechanism 160M. The second stage output shafts 175Y, C of the second second stage planetary gear mechanisms 170Y, C are connected to the second stage carriers 174Y, C rotating by the second second stage planetary gear mechanisms 170Y, C, respectively. Has been. In this way, by configuring the drive source sharing unit 112, the photosensitive drums 40Y, 40M, and 40C can be rotationally driven in the same direction with a simplified configuration with fewer components.

  In the present embodiment, the first second stage planetary gear mechanism 160M to which the rotational driving force is transmitted from the photosensitive member driving motor 106 via the first stage planetary gear reduction mechanism 150, and the second second stage planetary gear. The gear mechanisms 170 </ b> Y and 170 </ b> C are provided on one drive side plate 184. By providing on the driving side plate 184 in this way, it is necessary for the structure to hold the first second stage planetary gear mechanism 160M and the second second stage planetary gear mechanism 170Y, C compared to the structure to hold separately. In addition to reducing the number of members, the installation space can also be reduced. Therefore, it is possible to provide a planetary gear drive transmission device 110 that is smaller and less expensive.

Regarding the reduction ratio, when the number of teeth of the sun gear is Za, the number of teeth of the planetary gear is Zb, the number of teeth of the internal gear is Zc, and the intermediate gear is Zd, the reduction ratio of the photosensitive drum 40M is expressed by the following formula 4. It is represented by Here, the subscripts 1 and 2 in the formula mean the first and second stages.
Photosensitive drum 40M:
Reduction ratio = Za1 / (Za1 + Zc1) × Za2m / Zc2m (Formula 4)
Further, the reduction ratio of the photosensitive drum 40Y is expressed by the following formula 5.
Photosensitive drum 40Y:
Reduction ratio = Za1 / (Za1 + Zc1) × Za2y / (Za2y + Zc2y) × Zdm / Zdy (Equation 5)

  If the drum diameters of the photoconductor drum 40M and the photoconductor drum 40Y are the same, it is necessary to align the rotation speed. However, if the number of teeth of each planetary gear speed reduction mechanism of the photoconductor drum 40M and the photoconductor drum 40Y is the same, the reduction ratio is different, and therefore the rotation speed is also different. Therefore, in the present embodiment, the easiest way to align the reduction ratio is to adjust the reduction ratio by changing the number of teeth of each intermediate gear. In the configuration of the present embodiment, the number of teeth of the first intermediate gear 156M is greater than the number of teeth of the second intermediate gear 157Y.

  Thus, the reduction ratio from the photosensitive member drive motor 106 to the second stage output shaft 165M of the first second stage planetary gear mechanism 160M via the first stage planetary gear reduction mechanism 150, and the second two stage The speed reduction ratio up to the second stage output shaft 175Y of the first planetary gear mechanism 170Y can be easily aligned by changing the number of teeth of the second intermediate gear 157Y that meshes with the first intermediate gear 156M. it can. However, the present invention is not limited to such a configuration, and may be adjusted by changing the number of gear teeth constituting each planetary gear reduction mechanism.

(Example 2)
Next, Example 2 which is a second example of the present embodiment will be described with reference to the drawings. FIG. 9 is an explanatory diagram of the drive source sharing unit 112 in the planetary gear drive transmission device 110 of the present embodiment. Here, the first embodiment described above is different from the present embodiment only in the point relating to the configuration of the first stage planetary gear speed reduction mechanism 150 of the drive source sharing unit 112. Since other points relating to the configuration and operation are the same as those of the planetary gear drive transmission device 110 of the first embodiment described above, the same points will be omitted as appropriate. Further, with respect to the reference numerals of the constituent members, attention is paid to the functions thereof, and the same reference numerals as those in the first embodiment are used.

  As described above, the planetary gear drive transmission device 110 of the present embodiment is different from the first embodiment only in the configuration relating to the first stage planetary gear speed reduction mechanism 150 of the drive source sharing unit 112. Only the configuration of the source sharing unit 112 is shown. In the following description, only the drive source sharing unit 112 will be described. In this embodiment, as shown in FIG. 9, the fixing element of the first stage planetary gear reduction mechanism 150 provided coaxially with the photosensitive member driving motor 106 is replaced with the first stage internal gear 152 as in the first embodiment. In this example, the first-stage carrier 154 is used. The first stage carrier pin 154d is fixed to the motor bracket 180 and rotatably supports the first stage planetary gear 153. A rotatable first-stage internal gear 152 is disposed outside the first-stage planetary gear 153. The first-stage sun gear 151 geared to the motor output shaft 108 serving as the input shaft rotates, and the first-stage internal gear 152 rotates via the first-stage planetary gear 153.

  The first-stage internal gear 152 is integrally formed coaxially with the first intermediate gear 156M. Further, it meshes with a second stage sun gear 161M provided integrally on the same axis and a second stage planetary gear 163M disposed therearound. The second stage planetary gear 163M is rotatably supported by a second stage carrier pin 164dM fixed to the drive side plate 184. Further, a rotatable second-stage internal gear 162M is arranged outside the second-stage carrier pin 164dM, and the rotation of the second-stage sun gear 161M becomes the rotation of the second-stage internal gear 162M and the second-stage output. Output from shaft 165M. The configuration of drive transmission from the second-stage output shaft 165M to the photosensitive drum 40M of the first second-stage planetary gear mechanism 160M is the same as that of the first embodiment described with reference to FIG. The second second stage planetary gear mechanisms 170Y, C corresponding to the adjacent photosensitive drum 40Y and the photosensitive drum 40C, and the drive transmission configuration to each of the photosensitive drums 40Y, 40C are also described with reference to FIG. Since it is the same as that of Example 1, the description is abbreviate | omitted.

  The difference between the configuration of the first embodiment shown in FIG. 2 and the configuration of the present embodiment shown in FIG. 9 is that the component of the output shaft of the first stage planetary gear speed reduction mechanism 150 is the first stage carrier 154. The difference is whether it is a first-stage internal gear 152. Regarding the rotation direction, the output rotation direction of the first-stage planetary gear reduction mechanism 150 is different from the configuration of the first embodiment, but the first second-stage planetary gear mechanism 160M, which is the second-stage planetary gear mechanism, and the second The second stage planetary gear mechanisms 170Y, C have the same arrangement for aligning the rotation direction. Therefore, when the photosensitive drums 40Y, 40M, and 40C are rotated in the same direction as in the first embodiment, the rotation direction of the photosensitive member driving motor 106 may be rotated in the direction opposite to the rotation direction in the first embodiment.

  As described above, in this embodiment, the second stage sun gear 161M and the first intermediate gear 156M, which are the output shafts of the first stage planetary gear reduction mechanism 150, are included in the first stage in which the first stage planetary gear reduction mechanism 150 rotates. It is connected to the tooth gear 152. The second-stage output shaft 165M of the first second-stage planetary gear mechanism 160M is connected to the second-stage internal gear 162M that is rotated by the first second-stage planetary gear mechanism 160M. The second stage output shafts 175Y, C of the second second stage planetary gear mechanisms 170Y, C are connected to the second stage carriers 174Y, C rotating by the second second stage planetary gear mechanisms 170Y, C, respectively. Has been. In this way, by configuring the drive source sharing unit 112, the photosensitive drums 40Y, 40M, and 40C can be rotationally driven in the same direction with a simplified configuration with fewer components.

Further, regarding the reduction ratio, when the number of teeth of the sun gear is Za, the number of teeth of the planetary gear is Zb, the number of teeth of the internal gear is Zc, and the intermediate gear is Zd, the reduction ratio of the photosensitive drum 40M is as follows: It is expressed by Equation 6. Here, the subscripts 1 and 2 in the formula mean the first and second stages.
Photosensitive drum 40M:
Reduction ratio = Za1 / Zc1 × Za2m / Zc2m (Formula 6)
Further, the reduction ratio of the photosensitive drum 40Y is expressed by the following formula 7.
Photosensitive drum 40Y:
Reduction ratio = Za1 / Zc1 × Za2y / (Za2y + Zc2y) × Zdm / Zdy (Expression 7)

  Also in the present embodiment, the easiest way to align the reduction ratio is to adjust the reduction ratio by changing the number of teeth of each intermediate gear. In the configuration of the present embodiment, the number of teeth of the first intermediate gear 156M is greater than the number of teeth of the second intermediate gear 157Y. However, the present invention is not limited to such a configuration, and may be adjusted by changing the number of gear teeth constituting each planetary gear reduction mechanism.

(Example 3)
Next, Example 3 which is a third example of the present embodiment will be described with reference to the drawings. FIG. 10 is an explanatory diagram of the drive source sharing unit 112 in the planetary gear drive transmission device 110 of the present embodiment. Here, the first and second embodiments described above and the present embodiment differ only in the point relating to the configuration of the planetary gear speed reduction mechanism at each stage of the drive source sharing unit 112. Since other points relating to the configuration and operation are the same as those of the planetary gear drive transmission device 110 of the first and second embodiments, the same points will be omitted as appropriate. Further, with respect to the reference numerals of the constituent members, attention is paid to the function thereof, and the same reference numerals as those in the first and second embodiments are used.

  As described above, the planetary gear drive transmission device 110 of the present embodiment is different from the first and second embodiments only in the point relating to the planetary gear speed reduction mechanism of each stage of the drive source sharing unit 112. FIG. Only the configuration of the shared unit 112 is illustrated. In the following description, only the drive source sharing unit 112 will be described. In this embodiment, the first stage planetary gear reduction mechanism 150 provided coaxially with the photosensitive member driving motor 106 is a first stage internal gear 152 as in the first embodiment. The connection mode between the first stage planetary gear reduction mechanism 150 and the first intermediate gear 156M is the same as the mode described in FIG. 2 used in the description of the first embodiment except that the diameter of the first intermediate gear 156M is different. The description is omitted.

  First, the first second stage planetary gear mechanism 160M will be described. In the present embodiment, as shown in FIG. 10, the second-stage internal gear 162M is fixed to the drive side plate 184 while ensuring coaxial accuracy with the second-stage sun gear 161M. The coaxial accuracy of the fixed second-stage internal gear 162M and the second-stage sun gear 161M is a two-stage integrated with the first intermediate gear 156M in a bearing fitted in a hole provided in the drive side plate 184. The mesh sun gear 161M and the second-stage internal gear 162M are fitted and secured. The second stage sun gear 161M meshes with the second stage planetary gear 163M supported by the second stage carrier 164M, and the second stage planetary gear 163M also meshes with the second stage internal gear 162M. When the second-stage sun gear 161M rotates, the second-stage planetary gear 163M rotates and revolves around the second-stage sun gear 161M and the second-stage internal gear 162M, and the rotation rotates to the second-stage carrier 164M. Is output from the second-stage output shaft 165M. An inner tooth shape constituting the spline joint portion is formed on the inner surface of the cylindrical shaft of the second-stage output shaft 165M provided integrally with the second-stage carrier 164M, and the outer tooth shape provided on the drum shaft 41M is inserted. Then, the output of the first second stage planetary gear mechanism 160M is driven and transmitted to the drum shaft 41M, and the photosensitive drum 40M rotates.

  Next, the adjacent second stage planetary gear mechanisms 170Y and 170C will be described. Here, since the second second stage planetary gear mechanism 170Y and the second second stage planetary gear mechanism 170C have the same configuration, the second second stage planetary gear mechanism 170Y will be described below. The aspect of the second intermediate gear 157Y is the same as that used in the description of FIG. 2 used in the description of the first embodiment and the description of the second embodiment except for the diameter thereof, and the description thereof is omitted. Although the second stage planetary gear 173Y is arranged around the second stage sun gear 171Y, the second stage carrier pin 174dY that rotatably supports the second stage planetary gear 173Y is as in the first and second embodiments. The second stage carrier 174Y is not fixed to the driving side plate 184. A rotatable second-stage internal gear 172Y is arranged on the outside of the second-stage planetary gear 173Y. When the second-stage sun gear 171Y rotates, the rotation is transmitted to the second-stage internal gear 172Y that can rotate using the second-stage planetary gear 173Y as an idler gear. On the inner surface of the cylindrical shaft of the second-stage output shaft 175Y provided integrally with the second-stage internal gear 172Y, an internal tooth shape constituting the spline joint portion is formed, and the external tooth shape provided on the drum shaft 41Y. Is inserted, the output of the second second stage planetary gear mechanism 170Y is driven and transmitted to the drum shaft 41Y, and the photosensitive drum 40M rotates.

  The rotational direction of the photoconductive drum 40M and the photoconductive drum 40Y is such that the second stage output shaft 165M in the first second stage planetary gear mechanism 160M is a second stage carrier 164M, and the second second stage planetary gear. The components of the second-stage output shaft 175Y of the mechanism 170Y are aligned by using a second-stage internal gear 172Y.

  Thus, in the present embodiment, the second stage sun gear 161M and the first intermediate gear 156M, which are the output shafts of the first stage planetary gear reduction mechanism 150, are the first stage carrier that the first stage planetary gear reduction mechanism 150 rotates. 154. The second-stage output shaft 165M of the first second-stage planetary gear mechanism 160M is connected to the second-stage carrier 164M that is rotated by the first second-stage planetary gear mechanism 160M. The second stage output shafts 175Y, C of the second second stage planetary gear mechanisms 170Y, C are connected to the second stage internal gears 172Y, C rotated by the second second stage planetary gear mechanisms 170Y, C. Each is connected. In this way, by configuring the drive source sharing unit 112, the photosensitive drums 40Y, 40M, and 40C can be rotationally driven in the same direction with a simplified configuration with fewer components.

Further, regarding the reduction ratio, when the number of teeth of the sun gear is Za, the number of teeth of the planetary gear is Zb, the number of teeth of the internal gear is Zc, and the intermediate gear is Zd, the reduction ratio of the photosensitive drum 40M is as follows: It is expressed by Formula 8. Here, the subscripts 1 and 2 in the formula mean the first and second stages.
Photosensitive drum 40M:
Reduction ratio = Za1 / (Za1 + Zc1) × Za2m / (Za2m + Zc2m) (Equation 8)
Further, the reduction ratio of the photosensitive drum 40Y is expressed by the following formula 9.
Photosensitive drum 40Y:
Reduction ratio = Za1 / (Za1 + Zc1) × Za2y / Zc2y × Zdm / Zdy (Equation 9)

  Also in the present embodiment, the easiest way to align the reduction ratio is to adjust the reduction ratio by changing the number of teeth of each intermediate gear. In the configuration of the present embodiment, the number of teeth of the first intermediate gear 156M is smaller than the number of teeth of the second intermediate gear 157Y. However, the present invention is not limited to such a configuration, and may be adjusted by changing the number of teeth of the gears constituting the planetary gear mechanism.

  In the description of the copying machine 500 according to the present embodiment, the copying machine 500 provided with the four image forming units 18 of yellow (Y), magenta (M), cyan (C), and black (K) has been described as an example. However, the present invention is not limited to the image forming apparatus having such a configuration. For example, the present invention can be applied to an image forming apparatus including three image forming units of yellow (Y), magenta (M), and cyan (C). Further, the present invention can also be applied to an image forming apparatus having a two-color configuration that includes two image forming units of red (R) and black (K).

  Further, as in the copying machine 500 of this embodiment, each of the conventional photosensitive drums can be used by using any one of the planetary gear drive transmission devices 110 described in each example as a driving device for the plurality of photosensitive drums 40. Compared to the configuration in which the photosensitive member driving motor and the planetary gear speed reduction mechanism are independently provided, a small and low-cost image forming apparatus can be provided.

  Further, only the black photosensitive drum 40K, which is frequently used, is configured to be independently driven, and the planetary gear drive transmission device 110 described in each embodiment is used as a driving device for the photosensitive drums 40Y, 40M, and 40C of other colors. By using any of the configurations of the drive source sharing unit 112, the following effects can be obtained. Compared to a conventional configuration in which a photosensitive member driving motor and a planetary gear speed reduction mechanism are provided independently for each photosensitive drum, a small and low-cost image forming apparatus can be provided. In addition, when a monochrome image is formed, the photosensitive member driving motor 106 that rotates the photosensitive drums 40Y, 40M, and 40C of other colors can be stopped, and the unnecessary photosensitive drums 40Y, 40M, and 40C are rotationally driven. Can be avoided. Therefore, it is possible to provide an image forming apparatus that can save power and can also maintain the life of the photosensitive drums 40Y, 40M, and 40C and the components related to the rotational drive for a long time.

  Further, in the description of the present embodiment, the planetary gear drive transmission device 110 that decelerates the rotational driving force from the driving source used in the copying machine 500 and transmits it to each photosensitive drum 40 has been described. The present invention is not limited to the planetary gear drive transmission device having the configuration and the image forming apparatus including the planetary gear drive transmission device. For example, the present invention can be applied to a planetary gear drive transmission device that accelerates and transmits a rotational driving force from a driving source to a plurality of rotating bodies, and an image forming apparatus including the planetary gear drive transmission device.

What has been described above is merely an example, and the present invention has a specific effect for each of the following modes.
(Aspect A)
In a planetary gear drive transmission device such as a planetary gear drive transmission device 110 that transmits a rotational driving force of a drive source such as a photoconductor drive motor 106 to a rotary body such as a photosensitive drum via a planetary gear mechanism such as a planetary gear reduction mechanism. The first stage planetary gear reduction mechanism 150 is configured to transmit the rotational driving force from a single driving source to a plurality of rotating bodies such as the photosensitive drums 40Y, 40M, and 40C, and the rotational driving force of the driving source is directly input. Of the first stage planetary gear mechanism and the first second stage planetary gear mechanism 160M for transmitting the rotational driving force output from the output shaft of the first stage planetary gear mechanism to the corresponding rotating bodies, respectively. A plurality of second-stage planetary gear mechanisms such as second-stage planetary gear mechanisms 170Y and 170C, and two large and small external gears are provided on the output shaft of the first-stage planetary gear mechanism. The external gear of A rotational driving force output from the output shaft of the first stage planetary gear mechanism is transmitted to a first rotating body such as a photosensitive drum 40M provided coaxially with the output shaft of the first stage planetary gear mechanism. The second stage sun gear such as the second stage sun gear 161M that serves as the input shaft of the first second stage planetary gear mechanism such as the second stage planetary gear mechanism 160M. An input shaft of a second second-stage planetary gear mechanism such as second second-stage planetary gear mechanisms 170Y and C corresponding to a second rotary body such as the photosensitive drums 40Y and 40C adjacent to the first rotary body. And the second intermediate gear 157Y, C, etc., which is an external gear provided integrally and coaxially with the second second-stage sun gear such as the second-stage sun gear 171Y, C. A first transmission that transmits the rotational driving force output from the output shaft of the stage planetary gear mechanism. Is characterized in that the intermediate gear 156M, which is the first intermediate gear and the like.
According to this, as described in the first embodiment, the planetary gear drive transmission device 110 is smaller and less expensive than the conventional configuration in which the photosensitive member drive motor and the planetary gear speed reduction mechanism are provided independently for each photosensitive drum. And the like.
(Aspect B)
In (Aspect A), components of the output shaft such as the second stage output shaft 165M of the first second stage planetary gear mechanism such as the first second stage planetary gear mechanism 160M, and the second second stage The constituent elements of the output shaft such as the second-stage output shaft 175Y, C of the second second-stage planetary gear mechanism such as the planetary gear mechanism 170Y, C are different.
According to this, as described in the first embodiment, a rotating body such as the photosensitive drums 40Y, 40M, and 40C can be rotationally driven in the same direction with a simplified configuration with fewer components.
(Aspect C)
In (Aspect B), output shafts such as the second stage sun gear 161M and the first intermediate gear 156M of the first stage planetary gear mechanism such as the first stage planetary gear reduction mechanism 150 are connected to the first stage planetary gear mechanism. An output shaft such as a second stage output shaft 165M of the first second stage planetary gear mechanism such as a first second stage planetary gear mechanism 160M is connected to a carrier such as a rotating first stage carrier 154. The second second-stage planetary gear mechanism 170Y, C or the like is connected to an internal gear such as a second-stage internal gear 162M that rotates in the first second-stage planetary gear mechanism. The output shaft such as the second-stage output shaft 175Y, C in the gear mechanism is connected to a carrier such as the second-stage carrier 174Y, C rotating in the second second-stage planetary gear mechanism. Is.
According to this, as described in the first embodiment, a rotating body such as the photosensitive drums 40Y, 40M, and 40C can be rotationally driven in the same direction with a simplified configuration with fewer components.
(Aspect D)
In (Aspect B), output shafts such as the second stage sun gear 161M and the first intermediate gear 156M of the first stage planetary gear mechanism such as the first stage planetary gear reduction mechanism 150 are connected to the first stage planetary gear mechanism. Connected to an internal gear such as a rotating first-stage internal gear 152 and the like, the output of the second-stage output shaft 165M of the first second-stage planetary gear mechanism such as the first second-stage planetary gear mechanism 160M. The shaft is connected to an internal gear such as a rotating second-stage internal gear 162M of the first second-stage planetary gear mechanism, and the second second-stage planetary gear mechanism 170Y, C, etc. Output shafts such as second-stage output shafts 175Y and C in the second-stage planetary gear mechanism are connected to carriers such as second-stage carriers 174Y and C that rotate in the second second-stage planetary gear mechanism. It is characterized by.
According to this, as described in the second embodiment, a rotating body such as the photosensitive drums 40Y, 40M, and 40C can be rotationally driven in the same direction with a simplified configuration with fewer components.
(Aspect E)
In (Aspect B), output shafts such as the second stage sun gear 161M and the first intermediate gear 156M of the first stage planetary gear mechanism such as the first stage planetary gear reduction mechanism 150 are connected to the first stage planetary gear mechanism. An output shaft such as a second stage output shaft 165M of the first second stage planetary gear mechanism such as a first second stage planetary gear mechanism 160M is connected to a carrier such as a rotating first stage carrier 154. In the rotation of the first second stage planetary gear mechanism, the second second stage planetary gear mechanism such as the second second stage planetary gear mechanism 170Y, C is connected to a carrier such as the second stage carrier 164M. The output shaft such as the second-stage output shaft 175Y, C is connected to the internal gear such as the second-stage internal gear 172Y, C rotating in the second second-stage planetary gear mechanism. To do.
According to this, as described in the third embodiment, a rotating body such as the photosensitive drums 40Y, 40M, and 40C can be rotationally driven in the same direction with a simplified configuration with fewer components.
(Aspect F)
In any one of (Aspect A) to (Aspect E), the first two-stage planetary gear mechanism such as the first-stage planetary gear reduction mechanism 150 is supplied from the drive source such as the photoreceptor drive motor 106 to the first 2 A speed ratio such as a reduction ratio to the output shaft such as the second-stage output shaft 165M of the first second-stage planetary gear mechanism such as the second-stage planetary gear mechanism 160M, a second second-stage planetary gear mechanism 170Y, and the like. The second intermediate gear meshing with the first intermediate gear such as the first intermediate gear 156M with a speed ratio such as a reduction ratio to the output shaft such as the second-stage output shaft 175Y of the second second-stage planetary gear mechanism. The number of teeth of the second intermediate gear such as the gear 157Y is changed and aligned.
According to this, as described in the first embodiment, the first stage planetary gear mechanism 160M or the like such as the first second stage planetary gear mechanism 160M is passed from the drive source such as the photosensitive member drive motor 106 via the first stage planetary gear mechanism. A speed ratio such as a reduction ratio to the output shaft such as the second-stage output shaft 165M of the second-stage planetary gear mechanism, and 2 of the second second-stage planetary gear mechanism such as the second second-stage planetary gear mechanism 170Y. The gear ratio such as the reduction gear ratio to the output shaft such as the stage output shaft 175Y can be most easily aligned.
(Aspect G)
In any one of (Aspect A) to (Aspect F), the first second-stage planetary gear mechanism 160M and the second second-stage gear mechanism in which the rotational driving force is transmitted from one drive source such as the photosensitive member drive motor 106. A plurality of second-stage planetary gear mechanisms such as the planetary gear mechanisms 170Y and 170C are provided on one driving side plate such as the driving side plate 184.
According to this, as described in the first embodiment, it is possible to provide the planetary gear drive transmission device 110 that is smaller and lower in cost.
(Aspect H)
In an image forming apparatus such as a copying machine 500 including a plurality of photosensitive drums such as the photosensitive drums 40Y, 40M, 40C, and 40K, any one of (Aspect A) to (Aspect G) is included in the driving device of the photosensitive drum. The planetary gear drive transmission device such as the planetary gear drive transmission device 110 is used.
According to this, as described in the above embodiment, compared to the conventional configuration in which the photosensitive drum driving motor and the planetary gear speed reduction mechanism are provided independently for each photosensitive drum, the image formation of the copying machine 500 or the like that is small and low-cost is possible. Equipment can be provided.
(Aspect I)
In an image forming apparatus including a plurality of color photosensitive drums such as the photosensitive drums 40Y, 40M, 40C, and 40K, the configuration is such that only a frequently used black photosensitive drum such as the photosensitive drum 40K is driven independently. Planetary gears such as the drive source sharing unit 112 of the planetary gear drive transmission device 110 according to any one of (Aspects A) to (Aspect G). A drive transmission device is used.
According to this, as described in the above embodiment, compared to the conventional configuration in which the photosensitive drum driving motor and the planetary gear speed reduction mechanism are provided independently for each photosensitive drum, the image formation of the copying machine 500 or the like that is small and low-cost is possible. Equipment can be provided. In addition, it is possible to provide an image forming apparatus that can save power, and can maintain the life of the photosensitive drums such as the photosensitive drums 40Y, 40M, and 40C of other colors and the components related to the rotational driving thereof for a long time.

DESCRIPTION OF SYMBOLS 2 Charging device 4 Cleaning device 9 Developing device 10 Intermediate transfer belt 14 First support roller 15 Second support roller 16 Third support roller 17 Intermediate transfer belt cleaning device 18 Image forming unit 20 Tandem image forming unit 21 Exposure device 22 Secondary transfer Device 23a, b Roller 24 Secondary transfer belt 25 Fixing device 26 Fixing belt 27 Pressure roller 28 Sheet reversing device 30 Document table 32 Contact glass 33 First traveling member 34 Second traveling member 35 Imaging lens 36 Sensor 40 Photosensitive drum 41 Drum shaft 42 Paper feed roller 43 Paper bank 44 Paper feed cassette 45 Separation roller 46 Paper feed path 47 Transport roller 49 Registration roller 50 Paper feed roller 51 Tray 52 Separation roller 53 Paper feed path 55 Switching claw 56 Paper discharge roller 57 Paper discharge tray 100 Copy machine body 05, 106 Photoconductor drive motors 107, 108 Motor output shaft 110 Planetary gear drive transmission device 111 Single drive unit 112 Drive source sharing unit 120 Planetary gear speed reduction mechanism 121 First sun gear 122 Internal gear 123 First planetary gear 124 First Carrier 124a, b First carrier side plate 124c First carrier column 124d First carrier pin 125 Second sun gear 126 Second planetary gear 127 Second carrier 127a, b Second carrier side plate 127c Second carrier column 127d Second carrier pin 128 Output shaft 129 End cap 130 Motor bracket 132 Motor fixing flange 140 Photosensitive drum unit 141 Unit case 142 Front drum flange 143 Rear drum flange 144 Face plate 145 Pressure spring 146 Positioning pin 150 First stage planetary gear reduction mechanism 51 First stage sun gear 152 First stage internal gear 153 First stage planetary gear 154 First stage carrier 154d First stage carrier pin 156M First intermediate gear 157Y, C Second intermediate gear 160M First second stage planet Gear mechanism 161M Second stage sun gear 162M Second stage internal gear 163M Second stage planetary gear 164M Second stage carrier 164dM Second stage carrier pin 165M Second stage output shaft 169M Second stage end cap 170Y, C Second stage Second stage planetary gear mechanism 171Y Second stage sun gear 172Y, C Second stage internal gear 173Y Second stage planetary gear 174Y, C Second stage carrier 174dY Second stage carrier pin 175Y, C Second stage output shaft 179Y 2 Stage end cap 180 Motor bracket 183, 185 Stud 184 Drive side plate 190 Main body front plate 191 Main body rear plate 200 Paper table 300 Scanner 400 automatic document feeder 500 copier

Japanese Patent No. 4360162

Claims (11)

In the planetary gear drive transmission device that transmits the rotational driving force of the drive source to the rotating body via the planetary gear mechanism,
It is a configuration for transmitting rotational driving force from a single driving source to a plurality of rotating bodies,
A first stage planetary gear mechanism to which the rotational driving force of the driving source is directly input, and a plurality of 2 that transmit the rotational driving force output from the output shaft of the first stage planetary gear mechanism to the corresponding rotating bodies. A stage planetary gear mechanism,
The output shaft of the first stage planetary gear mechanism is provided with two large and small external gears,
The external gear on the smaller side transmits the rotational driving force output from the output shaft of the first stage planetary gear mechanism to the first rotating body provided coaxially with the output shaft of the first stage planetary gear mechanism. , A first second-stage sun gear serving as an input shaft of the first second-stage planetary gear mechanism,
The external gear on the larger side is integrated and coaxial with the second second-stage sun gear serving as the input shaft of the second second-stage planetary gear mechanism corresponding to the second rotary body adjacent to the first rotary body. the first intermediate gear der for transmitting the rotational driving force output from the output shaft of the provided the external gear at a second intermediate gear the first-stage planetary gear mechanism meshes with is,
Components of the output shaft of the first second stage planetary gear mechanism;
A planetary gear drive transmission device characterized in that a component of an output shaft of the second second stage planetary gear mechanism is different . In the planetary gear drive transmission device according to 請 Motomeko 1,
The output shaft of the first stage planetary gear mechanism is connected to the rotating carrier of the first stage planetary gear mechanism,
The output shaft of the first second stage planetary gear mechanism is connected to the rotating internal gear of the first second stage planetary gear mechanism,
An output shaft of the second second-stage planetary gear mechanism is connected to a rotating carrier of the second second-stage planetary gear mechanism. The planetary gear drive transmission device according to claim 1 ,
The output shaft of the first stage planetary gear mechanism is connected to the rotating internal gear of the first stage planetary gear mechanism,
The output shaft of the first second stage planetary gear mechanism is connected to the rotating internal gear of the first second stage planetary gear mechanism,
An output shaft of the second second-stage planetary gear mechanism is connected to a rotating carrier of the second second-stage planetary gear mechanism. The planetary gear drive transmission device according to claim 1 ,
The output shaft of the first stage planetary gear mechanism is connected to the rotating carrier of the first stage planetary gear mechanism,
The output shaft of the first second stage planetary gear mechanism is connected to the rotating carrier of the first second stage planetary gear mechanism,
An output shaft of the second second stage planetary gear mechanism is connected to the rotating internal gear of the second second stage planetary gear mechanism. In the planetary gear drive transmission device according to any one of claims 1 to 4 ,
A transmission ratio from the drive source to the output shaft of the first second-stage planetary gear mechanism via the first-stage planetary gear mechanism and a shift to the output shaft of the second second-stage planetary gear mechanism. Ratio
A planetary gear drive transmission device, wherein the number of teeth of the second intermediate gear meshing with the first intermediate gear is changed and aligned.   In the planetary gear drive transmission device that transmits the rotational driving force of the drive source to the rotating body via the planetary gear mechanism,
It is a configuration for transmitting rotational driving force from a single driving source to a plurality of rotating bodies,
A first stage planetary gear mechanism to which the rotational driving force of the driving source is directly input, and a plurality of 2 that transmit the rotational driving force output from the output shaft of the first stage planetary gear mechanism to the corresponding rotating bodies. A stage planetary gear mechanism,
The output shaft of the first stage planetary gear mechanism is provided with two large and small external gears,
The external gear on the smaller side transmits the rotational driving force output from the output shaft of the first stage planetary gear mechanism to the first rotating body provided coaxially with the output shaft of the first stage planetary gear mechanism. , A first second-stage sun gear serving as an input shaft of the first second-stage planetary gear mechanism,
The external gear on the larger side is integrated and coaxial with the second second-stage sun gear serving as the input shaft of the second second-stage planetary gear mechanism corresponding to the second rotary body adjacent to the first rotary body. A first intermediate gear that meshes with a second intermediate gear that is an external gear provided to transmit a rotational driving force output from the output shaft of the first stage planetary gear mechanism;
A transmission ratio from the drive source to the output shaft of the first second-stage planetary gear mechanism via the first-stage planetary gear mechanism and a shift to the output shaft of the second second-stage planetary gear mechanism. Ratio
A planetary gear drive transmission device, wherein the number of teeth of the second intermediate gear meshing with the first intermediate gear is changed and aligned. In the planetary gear drive transmission device according to any one of claims 1 to 6,
A planetary gear drive transmission device characterized in that a plurality of second-stage planetary gear mechanisms to which rotational driving force is transmitted from one drive source are provided on one drive side plate. In an image forming apparatus including a plurality of photosensitive drums,
An image forming apparatus using the planetary gear drive transmission device according to any one of claims 1 to 7 as a drive device for the photosensitive drum. In an image forming apparatus including a plurality of color photosensitive drums,
The planetary gear drive transmission device according to any one of claims 1 to 7 is used as a drive device for the photosensitive drums of other colors, in which only the frequently used black photosensitive drum is driven independently. An image forming apparatus.   In an image forming apparatus including a plurality of photosensitive drums,
In the photosensitive drum drive device,
A planetary gear drive transmission device that transmits a rotational driving force of a driving source to a rotating body via a planetary gear mechanism,
It is a configuration for transmitting rotational driving force from a single driving source to a plurality of rotating bodies,
A first stage planetary gear mechanism to which the rotational driving force of the driving source is directly input, and a plurality of 2 that transmit the rotational driving force output from the output shaft of the first stage planetary gear mechanism to the corresponding rotating bodies. A stage planetary gear mechanism,
The output shaft of the first stage planetary gear mechanism is provided with two large and small external gears,
The external gear on the smaller side transmits the rotational driving force output from the output shaft of the first stage planetary gear mechanism to the first rotating body provided coaxially with the output shaft of the first stage planetary gear mechanism. , A first second-stage sun gear serving as an input shaft of the first second-stage planetary gear mechanism,
The external gear on the larger side is integrated and coaxial with the second second-stage sun gear serving as the input shaft of the second second-stage planetary gear mechanism corresponding to the second rotary body adjacent to the first rotary body. A planetary gear drive transmission device that is a first intermediate gear that meshes with a second intermediate gear that is an external gear provided to transmit a rotational driving force output from an output shaft of the first stage planetary gear mechanism.
An image forming apparatus used.   In an image forming apparatus including a plurality of color photosensitive drums,
Only the black photosensitive drum that is frequently used is configured to be driven independently.
A planetary gear drive transmission device that transmits a rotational driving force of a driving source to a rotating body via a planetary gear mechanism,
It is a configuration for transmitting rotational driving force from a single driving source to a plurality of rotating bodies,
A first stage planetary gear mechanism to which the rotational driving force of the driving source is directly input, and a plurality of 2 that transmit the rotational driving force output from the output shaft of the first stage planetary gear mechanism to the corresponding rotating bodies. A stage planetary gear mechanism,
The output shaft of the first stage planetary gear mechanism is provided with two large and small external gears,
The external gear on the smaller side transmits the rotational driving force output from the output shaft of the first stage planetary gear mechanism to the first rotating body provided coaxially with the output shaft of the first stage planetary gear mechanism. , A first second-stage sun gear serving as an input shaft of the first second-stage planetary gear mechanism,
The external gear on the larger side is integrated and coaxial with the second second-stage sun gear serving as the input shaft of the second second-stage planetary gear mechanism corresponding to the second rotary body adjacent to the first rotary body. A planetary gear drive transmission device that is a first intermediate gear that meshes with a second intermediate gear that is an external gear provided to transmit a rotational driving force output from an output shaft of the first stage planetary gear mechanism.
An image forming apparatus used.

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