JP2015084020A - Drive transmission device and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a drive transmission device that includes an intermediate transmission member on a drive transmission path between a driving source and a rotating body, and can reduce the length of a device main body in the rotation center line direction of the rotating body.SOLUTION: A photoreceptor drive transmission device 70 is provided with a drum shaft 50 that transmits a rotation drive force to a photoreceptor drum 1, and an external tooth gear 83 that is press-fit into the drum shaft 50. The photoreceptor drive transmission device 70 is further provided with an internal tooth gear part 84 that engages with the external tooth gear 83, and an intermediate transmission member 85 that has the rotation center collinear with the rotation center of the tooth profile of an external tooth gear part 86, which is engaged with a tooth part 87 inside a rotating body that is formed in a rear-side flange member 53a of the photoreceptor drum 1. The internal tooth gear part 84 and external tooth gear part 86 are both provided inside the photoreceptor drum 1 with respect to an end on a driving source side of the outer periphery of the rear-side flange member 53a in the rotation center line direction of the photoreceptor drum 1.

Description

  The present invention relates to a drive transmission device that transmits a rotational driving force to a rotating body, and an image forming apparatus including the drive transmission device.

An electrophotographic image forming apparatus includes a rotating body such as a photoconductor and a developing roller, and rotates the rotating body to form an image. Such a rotating body is divided into a drive source side unit (hereinafter referred to as a drive unit) provided on the apparatus main body side and a unit (hereinafter referred to as a rotation) in order to improve workability during assembly to the apparatus main body or replacement. As part of a body unit). In this case, the drive transmission device that transmits the rotational driving force of the drive unit to the rotating body includes a drive coupling means such as a spline coupling that can connect and disconnect the output member of the drive unit and the input member of the rotating body unit. Is provided.
For example, Patent Document 1 describes a drive transmission device (drive device) including an intermediate transmission member as described below in a drive transmission path between a drive source and a rotating body as drive connection means using a gear. Has been.

The drive transmission device described in FIG. 2 and the like of Patent Document 1 is arranged on the drive source side from the center to the end on the drive source side in the rotation center line direction (hereinafter referred to as the center line direction) of the photosensitive drum which is a rotating body. A flange member formed with a cylindrical input portion projecting from is fixed. Inner teeth are formed on the inner periphery of the cylindrical input portion formed on the flange member, and constitute an input gear of the inner teeth.
On the other hand, a planetary gear mechanism in which the motor output shaft of the drive motor that is the drive source is a sun gear is provided on the drive source side, and the inner periphery of the cylindrical output unit that is provided integrally with the carrier of the final stage is provided Inner teeth are formed to form an output gear of the inner teeth.
As a drive connecting means using a gear, a tooth portion on the driving source side that meshes with the output gear and a tooth portion on the rotating body side that meshes with the input gear are formed so that the centers of the tooth shapes are on the same straight line. An intermediate transmission member.
With the above-described configuration, the first-stage meshing portion where the output gear and the tooth portion on the drive source side of the intermediate transmission member mesh, and the two-stage meshing portion of the intermediate transmission member on the rotating body side and the input gear. A coupling (hereinafter referred to as a two-stage coupling) having an eye meshing portion is formed.

In the drive transmission device of Patent Document 1, by providing the above-described two-stage coupling, it is possible to improve workability when assembling or replacing the device body.
However, in the drive transmission device described in Patent Document 1, a drive source in the direction of the center line rather than an end on the outermost drive source side in the radial direction of the photosensitive drum (hereinafter referred to as an outer drive source side end). On the side, all of the intermediate transmission member is located.
In each meshing portion of the intermediate transmission member, it is necessary to secure a minimum meshing width according to the rotational driving force transmitted from the driving source to the photosensitive drum, and therefore, it is necessary according to the rotational driving force to be transmitted. An intermediate transmission member that is longer than the sum of the minimum engagement widths is provided.
For these reasons, only the minimum necessary length of the intermediate transmission member in the center line direction is the portion of the outer periphery of the photosensitive drum excluding the portion where the output gear of the last stage carrier is formed from the drive source side end. It is necessary to secure a distance to the rotating body side end (hereinafter referred to as drive side end).

Due to the above demand, there is a problem that it is difficult to reduce the size of the apparatus main body (image forming apparatus) provided with the rotating body in the direction of the rotation center line of the rotating body such as the photosensitive drum.
The above problems are not limited to the drive transmission device having the planetary gear mechanism as the transmission mechanism on the drive source side, but in the configuration having the gear train as the transmission mechanism or the drive transmission device not having the transmission mechanism. Can occur as well.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an intermediate transmission member in a drive transmission path between a drive source and a rotating body, and to extend the length of the apparatus main body in the direction of the rotation center line of the rotating body. This is a drive transmission device that can shorten the length.

  In order to achieve the above object, according to a first aspect of the present invention, in a drive transmission device including an intermediate transmission member in a drive transmission path between a drive source and a rotating body, a rotational driving force is transmitted to the rotating body. A transmission shaft that is fixed to the transmission shaft, and the intermediate transmission member includes an intermediate internal tooth portion having an inner tooth formed on the same straight line and a center of the tooth profile. An intermediate external tooth portion on which teeth are formed, the intermediate internal tooth portion meshes with the shaft external tooth member, and the intermediate external tooth portion meshes with a rotary internal tooth portion of an internal tooth provided on the rotary body, In the rotation center line direction of the rotating body, at least one of the intermediate internal tooth portion and the intermediate external tooth portion is provided on the inner side of the rotating body than the end portion on the drive source side of the outer periphery of the rotating body. To do.

  The present invention can provide a drive transmission device that includes an intermediate transmission member in a drive transmission path between a drive source and a rotating body, and that can shorten the length of the apparatus main body in the rotation center line direction of the rotating body.

1 is an overall schematic diagram of a copier according to an embodiment. FIG. 3 is an explanatory diagram of a photosensitive member drive transmission device and a photosensitive drum according to the first exemplary embodiment. FIG. 3 is an explanatory diagram of a drive connecting portion and a photoconductor drum provided in the photoconductor drive transmission device according to the first embodiment. Explanatory drawing of the crowning process given to the external gear which is an intermediate | middle external tooth part of the external tooth of an intermediate transmission member. Explanatory drawing of the effect acquired by performing a crowning process to each tooth | gear part of an intermediate transmission member. Explanatory drawing of the metal mold | die in the case of shape | molding the intermediate | middle transmission member which has a tooth | gear part which gave the crowning process. FIG. 5 is an explanatory diagram of a photosensitive member drive transmission device and a photosensitive drum according to a second embodiment. FIG. 6 is an explanatory diagram of a drive connecting portion and a photosensitive drum provided in the photosensitive member drive transmission device according to the second embodiment.

Hereinafter, an embodiment in which the present invention is applied to an electrophotographic color copier as an image forming apparatus will be described with reference to the drawings.
First, an overall outline of the copying machine 500 of this embodiment will be described.
FIG. 1 is an overall schematic diagram of a copying machine 500 according to the present embodiment.
The copier 500 in the present embodiment is a so-called tandem image forming apparatus, and employs a dry two-component developing system using a dry two-component developer. The copying machine 500 includes a copying machine main body 100, a paper feed table 200 on which the copying machine main body 100 is placed, a scanner 300 mounted on the copying machine main body 100, and an automatic document feeder 400 mounted on the scanner 300. Yes.

  The copier 500 receives image data that is image information read from the scanner 300 or print data from an external device such as a personal computer to perform image forming processing. As shown in the figure, the copying machine main body 100 includes a photosensitive member which is a latent image carrier as four rotating bodies for each color of yellow (Y), magenta (M), cyan (C), and black (Bk). Body drums 1Y, 1M, 1C, and 1Bk are juxtaposed. These photosensitive drums 1Y, 1M, 1C, and 1Bk are arranged along the belt moving direction so as to contact the endless belt-shaped intermediate transfer belt 5 supported by a plurality of rotatable rollers including a driving roller. Is arranged.

  Further, around the photosensitive drums 1Y, 1M, 1C, and 1Bk, the following electrophotographic process members are arranged in the order of processes. Electrophotographic process members such as chargers 2Y, 2M, 2C, 2Bk, developing devices 9Y, 9M, 9C, 9Bk corresponding to each color, cleaning devices 4Y, 4M, 4C, 4Bk, static elimination lamps 3Y, 3M, 3C, 3Bk is there. An optical writing device 17 is provided above each photosensitive drum 1. In addition, primary transfer rollers 6Y, 6M, 6C, and 6Bk, which are primary transfer units, are disposed at positions facing each other through the intermediate transfer belt 5 of each photosensitive drum 1.

  The intermediate transfer belt 5 is stretched around stretching rollers 11, 12, 13 and a tension roller 14, and is driven to rotate by the rotation of the stretching roller 12, which is a driving roller that is rotationally driven by a drive source (not shown). . A belt cleaning device 19 is provided at a position facing the stretching roller 13 through the intermediate transfer belt 5, and removes residual toner remaining on the intermediate transfer belt 5 after the secondary transfer. The stretching roller 11 is a secondary transfer counter roller that faces the secondary transfer roller 7 that is a secondary transfer unit, and is connected to the secondary transfer roller 7 via the intermediate transfer belt 5. Forming part.

  On the downstream side of the secondary transfer nip portion in the transfer sheet conveyance direction, a transfer sheet conveyance belt 15 stretched around a pair of stretching rollers 16 is provided, and a transfer medium that is a recording medium on which a toner image is secondarily transferred. The paper is conveyed to the fixing device 18. The fixing device 18 includes a fixing roller pair 8, and heat and pressure are applied at the fixing nip portion to fix the unfixed toner image on the transfer paper.

Next, the copying operation of the copying machine 500 in this embodiment will be described.
When a full-color image is formed by the copying machine 500 according to the present embodiment, first, a document is set on the document table 401 of the automatic document feeder 400. Alternatively, the automatic document feeder 400 is opened, a document is set on the contact glass 301 of the scanner 300, and the automatic document feeder 400 is closed and pressed. Thereafter, when the user presses a start switch (not shown), when the document is set on the automatic document feeder 400, the document is conveyed onto the contact glass 301.

  Then, the scanner 300 is driven and the first traveling body 302 and the second traveling body 303 start traveling. Thereby, the light from the first traveling body 302 is reflected by the document on the contact glass 301, and the reflected light is reflected by the mirror of the second traveling body 303 and guided to the reading sensor 305 through the imaging lens 304. . In this way, the image information of the original is read.

When the user, who is a user, presses the start switch, a motor (not shown) is driven, and the stretching roller 12 as a driving roller is driven to rotate, so that the intermediate transfer belt 5 is driven to rotate.
At the same time, the photosensitive drum 1Y is uniformly charged by the charger 2Y while being driven to rotate in the direction of the arrow in the drawing by a photosensitive member driving device (not shown) described later. Thereafter, a light beam Ly from the optical writing device 17 is irradiated to form a Y electrostatic latent image on the photosensitive drum 1Y.
This Y electrostatic latent image is developed with Y toner in the developer by the developing device 9Y. During development, a predetermined developing bias is applied between the developing roller and the photosensitive drum 1Y, and the Y toner on the developing roller is electrostatically attracted to the Y electrostatic latent image portion on the photosensitive drum 1Y.

The Y toner image developed and formed in this way is conveyed to a primary transfer position where the photosensitive drum 1Y and the intermediate transfer belt 5 come into contact with the rotation of the photosensitive drum 1Y. At this primary transfer position, a predetermined bias voltage is applied to the back surface of the intermediate transfer belt 5 by the primary transfer roller 6Y. The Y toner image on the photosensitive drum 1Y is drawn toward the intermediate transfer belt 5 by the primary transfer electric field generated by the bias application, and is primarily transferred onto the intermediate transfer belt 5.
Thereafter, similarly, the M toner image, the C toner image, and the Bk toner image are also primarily transferred so as to sequentially overlap the Y toner image on the intermediate transfer belt 5.
The transfer residual toner remaining on each photosensitive drum 1 after the primary transfer is removed by each cleaning device 4.

When the user presses the start switch, the paper feed roller 202 of the paper feed table 200 corresponding to the transfer paper selected by the user rotates, and the transfer paper is sent out from one of the paper feed cassettes 201. The transferred transfer paper is separated into one sheet by the separation roller 203 and enters the paper feed path 204, and is transported to the paper feed path 101 in the copying machine main body 100 by the transport roller 205. The transfer paper conveyed in this way is stopped when it strikes the registration roller 102.
When using transfer paper that is not set in the paper feed cassette 201, the transfer paper set on the manual feed tray 105 is fed out by the paper feed roller 104 and separated into one sheet by the separation roller 108, and then the manual paper feed path. It is conveyed through 103. Then, it stops when it hits the registration roller 102.

The toner images with the four colors superimposed on the intermediate transfer belt 5 are conveyed to a secondary transfer position facing the secondary transfer roller 7 as the intermediate transfer belt 5 rotates. Further, the registration roller 102 starts to rotate in accordance with the timing at which the composite toner image formed on the intermediate transfer belt 5 as described above is conveyed to the secondary transfer position, and the transfer paper is moved to the secondary transfer position. Transport. At this secondary transfer position, a predetermined bias voltage is applied to the back surface of the transfer paper by the secondary transfer roller 7, and due to the secondary transfer electric field generated by the bias application and the contact pressure at the secondary transfer position, The toner image on the intermediate transfer belt 5 is secondarily transferred collectively onto the transfer paper.
The transfer residual toner remaining on the intermediate transfer belt 5 after the secondary transfer is removed by the belt cleaning device 19.

Thereafter, the transfer paper on which the toner image has been secondarily transferred is conveyed to the fixing device 18 by the transfer paper conveying belt 15 and subjected to fixing processing by the fixing roller pair 8 provided in the fixing device 18. The transfer sheet on which the fixing process has been performed is discharged and stacked in a discharge tray 107 provided outside the apparatus by a discharge roller pair 106.
In this embodiment, an example in which the present invention is applied to the copying machine 500 that is an image forming apparatus will be described. However, the present invention is not limited to such a configuration, and a printer, a facsimile apparatus, or a printing machine is not limited thereto. It can also be applied to multi-function machines that combine these functions.

Next, each photoconductor drive transmission device 70 that is a drive transmission device provided in each photoconductor drive device 10 that is a drive device that rotationally drives each photoconductor drum 1 provided in the copier 500 of the present embodiment, and The characteristics of each photosensitive drum 1 will be described with reference to a plurality of examples.
The photosensitive drums 1Y, 1M, 1C, and 1Bk are rotationally driven by the photosensitive member driving devices 10Y, 10M, 10C, and 10Bk having the same configuration, and the photosensitive member driving transmission devices 70Y and 70Y provided in the respective photosensitive member driving devices 10 are provided. 70M, 70C, and 70Bk have the same configuration. Therefore, in the following description, the symbols Y, M, C, and Bk are omitted unless it is necessary to specify the corresponding color.
In addition, even if the devices and components have different shapes and the like for each embodiment, the devices and components that perform the same function are given the same reference numerals unless otherwise distinguished, and the same designations are used. It explains using.

Example 1
Example 1 of the photoconductor drive transmission device 70 which is a drive transmission device provided in the photoconductor drive device 10 of this embodiment will be described with reference to the drawings.
FIG. 2 is an explanatory diagram of the photosensitive member drive transmission device 70 and the photosensitive drum 1 according to the present embodiment, and FIG. 3 illustrates a drive connecting unit 80 and a photosensitive member provided in the photosensitive member drive transmission device 70 according to the present embodiment. 2 is an explanatory diagram of a body drum 1. FIG. FIG. 4 is an explanatory diagram of the crowning process performed on the external gear 86, which is an intermediate external tooth part of the external teeth of the intermediate transmission member 85, and FIG. 5 shows the crowning process performed on each tooth part of the intermediate transmission member 85. It is explanatory drawing of the effect acquired. FIG. 6 is an explanatory view of the mold 90 when the intermediate transmission member 85 having each tooth portion subjected to the crowning process is formed.

  As described with reference to FIG. 1, the photoconductor drum 1 that is a rotating body is mounted on the copying machine main body 100. Then, as shown in FIG. 2, it is connected and attached to an output gear 67 installed on the copying machine main body 100 side via a connecting portion. The photosensitive drum 1 includes a cylindrical drum cylinder (photosensitive drum main body) 52, a rear side flange member 53a and a front side flange member 53b that are end fixing members. The front side flange member 53b and the rear side flange member 53a are fixed so as to be fitted into both end portions of the drum cylinder 52 of the photosensitive drum 1. Further, on the inner side of the photosensitive drum 1 of the rear flange member 53a, a coaxial is a coaxial regulating member that regulates the coaxiality between the drum shaft 50 as a transmission shaft and the rear side (drive source side) of the photosensitive drum 1. A regulating member 59 is provided.

  A drum shaft 50 (rotating shaft), which is a transmission shaft supported by bearings 51a, 51b, 51d provided on the photosensitive drum unit frame 54, passes through the center of the front flange member 53b and the rear flange member 53a. It is inserted. The drum shaft 50 has a metal whose outer diameter is reduced to about 10 [mm] on the drive source side, and more specifically, to an outer diameter of about 8 [mm] on the front side for fixing an external gear 83 which is a shaft outer tooth member described later. It is a shaft, and both the rear side and the front side, which are the drive side, have high axial rigidity and little deflection.

  The photosensitive drum unit frame 54 is a housing of the photosensitive drum unit that houses the photosensitive drum 1. When the photosensitive drum 1 is taken out from the image forming apparatus main body for replacement or the like, the whole photosensitive drum unit frame 54 is taken out. On the drive source side of the photosensitive drum 1, a rotating body tooth portion 87 (spline coupling output portion) with the drum shaft 50 as a rotation center is formed in the rear flange member 53a. The front side of the drum shaft 50 is positioned on the copying machine main body 100 by being supported by a bearing 51 d installed on an attachment face plate 61 a attached to the front side main body frame 61.

  Connection of the photosensitive drum unit frame 54 to the drum shaft 50 on the drive source side is performed as follows so that the photosensitive drum unit frame 54 does not rotate as the drum shaft 50 rotates. The outer peripheral portion of the disc-shaped drum unit positioning member 56 fixed to the bearing 51c fitted to the drum shaft 50 is fitted into the inner peripheral portion of the opening provided on the side plate on the drive source side of the photosensitive drum unit frame 54. .

  Next, the photosensitive member driving device 10 for driving the photosensitive drum 1 will be described. As shown in FIG. 2, the photosensitive member driving device 10 for driving the photosensitive drum 1 provided in the copying machine main body 100 includes a driving motor 20, a motor output shaft 21, a motor gear 68, an output gear 67, and a drum shaft 50. , And an external gear 83 (spline coupling input unit) and the like. The drive motor 20 is attached to the drive frame 63 of the copying machine main body 100. An external gear gear 68 is formed on the motor output shaft 21 of the drive motor 20 and meshes with an output gear 67 that is coaxially fixed to the drum shaft 50. The output gear 67 is attached to the drum shaft 50 and transmits the rotational driving force from the drive motor 20 to the drum shaft 50.

  The rear side of the drum shaft 50 is supported and positioned on the copier main body 100 side by a bearing 51 a attached to the drive frame 63 and a bearing 51 b attached to the rear side main body frame 62 of the copier main body 100. The front side of the drum shaft 50 is positioned on the copying machine main body 100 by being supported by a bearing 51 d provided on a mounting face plate 61 a attached to the front side main body frame 61. By supporting and positioning the drum shaft 50 in this manner, the drum shaft 50 having a small amount of bending as described above is unlikely to generate low-frequency vibration during image formation, and the periodic density unevenness of an image called banding. Can be suppressed.

Here, conventionally, as in this embodiment, the output rotation shaft is extended from the drive unit on the image forming apparatus main body side to the support position of the photosensitive drum, and the hollow photosensitive drum unit is used as the rotation shaft (drum shaft). A configuration for mounting is proposed. According to this, since the photosensitive drum unit is positioned on the rotation shaft, there is no axial deviation and high-accuracy drive transmission is possible.
However, the same problem as the shaft misalignment may occur depending on the accuracy of the parts used in the connecting means for connecting the photosensitive drum and the rotating shaft. For example, the eccentricity of the external gear formed on the flange provided on the photosensitive drum or the eccentricity of the external gear press-fitted into the rotating shaft may cause the displacement of the connecting portion in the same manner as the shaft misalignment. This becomes a cause of occurrence of rotation transmission error and axial reaction force, and causes deterioration of image quality.

Also, if the connecting means for connecting the photosensitive drum and the rotating shaft is fixedly connected by screw fastening or by a coupling with a small allowable error range, a large axial reaction force is generated on each shaft, and the photosensitive drum unit Deformation or large vibrations.
In addition to the photosensitive drum, the photosensitive unit may include a developing device including a developing roller, a charging device, a static eliminating device, and a cleaning device. In such a large photosensitive unit (process cartridge), the positioning accuracy at the time of mounting is lowered, and the shaft misalignment and the shaft deflection angle are likely to become larger.

Therefore, in the photoreceptor drive transmission device 70 of the present embodiment, a spline coupling (hereinafter referred to as a two-stage coupling) having a two-stage (two) meshing portion known as a connecting means having a wide allowable error range. In the drive transmission path between the drive motor 20 and the photosensitive drum 1.
Specifically, the two-stage coupling includes an intermediate transmission member 85 in which an intermediate inner tooth portion and an intermediate outer tooth portion are formed as follows. An internal gear portion 84 that is an intermediate internal gear portion is formed so as to mesh with an external gear 83 that is an externally toothed shaft member that is press-fitted into the drum shaft 50. Further, the external gear portion 86 which is an intermediate external tooth portion is formed so as to mesh with the rotating body tooth portion 87 provided on the inner periphery of the rear side flange member 53a. And the center of the tooth profile of the internal gear part 84 of the intermediate transmission member 85 and the external gear part 86 is formed so that it may be on the same straight line.

  In this embodiment, the drive source side end on the outer periphery of the photoconductive drum 1 in the direction of the rotation center line of the photoconductive drum 1 is the rear side flange member 53 a and the drive source side end on the outer periphery of the drum cylinder 52. This is the drive source side end of the outer periphery of the rear flange member 53a. The internal gear portion 84 and the intermediate external teeth of the internal teeth that are intermediate internal teeth of the intermediate transmission member 85 are located on the inner side of the photosensitive drum 1 than the end on the drive source side of the outer periphery of the rear flange member 53a. Both external gears 86 which are external teeth are provided.

By configuring the photosensitive member drive transmission device 70 as described above, the following effects can be obtained.
Unlike the conventional configuration in which all of the intermediate transmission member is located closer to the drive source side in the rotation center line direction of the rotating body than the end portion on the outer periphery of the rotating body, the internal gear portion 84 and the external gear portion 86 Both are provided on the inner side of the photosensitive drum 1 from the drive source side end of the outer periphery of the photosensitive drum 1. Therefore, the distance required from the drive source side end on the outer periphery of the photosensitive drum 1 in the direction of the rotation center line of the photosensitive drum 1 to provide the intermediate transmission member 85 is more reliable than the conventional configuration. Can be shortened. Therefore, the length of the copying machine main body 100 in the direction of the rotation center line of the photosensitive drum 1 can be made shorter than that of the conventional configuration.

Further, the internal gear portion 84 and the external gear portion 86 are formed in two cylindrical shape portions provided on the intermediate transmission member 85, respectively. The internal gear portion 84 is formed on the inner periphery of the small-diameter cylindrical portion having the smaller outer diameter, and the external gear portion 86 is formed on the outer periphery of the large-diameter cylindrical portion having the larger outer diameter. The internal gear portion 84 is provided on the inner side of the photosensitive drum 1 in the rotation center line direction of the photosensitive drum 1 than the external gear portion 86.
By configuring in this way, the internal gear portion 84 that meshes with the external gear 83 is surely disposed on the photosensitive drum 1 rather than on the drive source side end on the outer periphery of the photosensitive drum 1 (rear side flange member 53a). It can be provided inside the photosensitive drum 1 in the rotation center line direction.
Therefore, in order to provide the intermediate transmission member 85, the distance required from the drive source side end of the outer periphery of the photosensitive drum 1 in the direction of the rotation center line of the photosensitive drum 1 to the drive source side is more reliable than in the conventional configuration. It is possible to shorten the time.

Further, the drive source side end portion of the rotating body tooth portion 87 is on the drive source side of the outer periphery of the rear flange member 53a which is the drive source side end portion of the outer periphery of the photoconductive drum 1 in the rotation center line direction of the photoconductive drum 1. It is provided inside the photosensitive drum 1 from the end. The intermediate transmission member 85 has a reference circle diameter of external teeth of the external gear portion 86 larger than a reference circle diameter of internal teeth of the internal gear portion 84.
By configuring in this way, the following effects can be achieved.

  The drive source side end of the rotating body tooth portion 87 is provided on the inner side of the photoconductive drum 1 than the drive source side end of the outer periphery of the photoconductive drum 1 (rear side flange member 53a). For this reason, a part of the intermediate transmission member 85 can be reliably provided inside the photosensitive drum 1 in the rotation center line direction of the photosensitive drum 1 with respect to the driving source side end of the outer periphery of the photosensitive drum 1. The internal gear portion 84 is provided on the inner side of the photosensitive drum 1 in the rotation center line direction of the photosensitive drum 1 than the rotating internal tooth portion 87. For this reason, most of the intermediate transmission member 85 can be provided on the inner side of the photosensitive drum 1 in the direction of the rotation center line of the photosensitive drum 1 with respect to the driving source side end on the outer periphery of the photosensitive drum 1.

Further, the reference circle diameter of the external teeth of the external gear portion 86 is larger than the internal teeth of the internal gear portion 84. Thus, the meshing portion where the external gear 83 and the internal gear portion 84 mesh is more easily provided inside the photosensitive drum 1 than the meshing portion where the rotating body tooth portion 87 and the external gear portion 86 mesh. Can do.
Therefore, in order to provide the intermediate transmission member 85, the distance required from the drive source side end of the outer periphery of the photosensitive drum 1 in the direction of the rotation center line of the photosensitive drum 1 to the drive source side is significantly larger than that of the conventional configuration. And it becomes possible to shorten easily.

In the above-described embodiment, both the internal gear portion 84 and the external gear portion 86 are the drive source side end portions of the outer periphery of the rear flange member 53a, which is the drive source side end portion of the outer periphery of the photosensitive drum 1. In the above, the example provided inside the photosensitive drum 1 has been described. However, the present invention is not limited to such a configuration.
At least one of the internal gear portion 84 and the external gear portion 86 may be provided on the inner side of the photosensitive drum 1 with respect to the driving source side end of the outer periphery of the photosensitive drum 1. With this configuration, the intermediate transmission member 85 is different from the configuration in which all of the intermediate transmission member is positioned closer to the drive source side than the drive source side end of the outer periphery of the rotary body in the direction of the rotation center line of the rotary body. At least a part of which can be provided inside the photosensitive drum 1.

Therefore, the intermediate transmission member 85 is provided from the driving source side end portion of the outer periphery of the rear flange member 53a, which is the driving source side end portion of the outer periphery of the photosensitive drum 1 in the rotation center line direction of the photosensitive drum 1. The distance required on the side can be shortened compared to the conventional configuration.
Therefore, the following photoreceptor drive transmission device 70 can be provided.
The photosensitive member drive transmission device 70 includes an intermediate transmission member 85 in the drive transmission path between the drive motor 20 and the photosensitive drum 1, and can shorten the length of the copying machine main body 100 in the rotation center line direction of the photosensitive drum 1. is there.
In this embodiment, as described above, the driving source side end portion of the rotating body tooth portion 87 is located more in the direction of the rotation center line of the photosensitive drum 1 than the driving source side end portion on the outer periphery of the photosensitive drum 1. The inner side of the drum 1 or the outer periphery of the photosensitive drum 1 is provided at the same position as the driving source side end. By configuring in this manner, a part of the intermediate transmission member 85 is surely placed on the inner side of the photosensitive drum 1 in the rotation center line direction of the photosensitive drum 1 with respect to the driving source side end on the outer periphery of the photosensitive drum 1. Can be provided.

  Further, the two-stage coupling of the present embodiment is configured such that the internal gear portion 84 and the external gear portion 86 of the intermediate transmission member 85 are connected to the external gear 83 and the rotating internal gear portion 87 to be connected to each other with respect to the axial deviation and the axial deflection angle. It has the effect of absorbing errors and reducing rotation transmission errors. The effect of reducing this rotation transmission error is absorbed by the fact that the intermediate transmission member that connects the two shafts where the shaft misalignment or the shaft declination has occurred, as known in the past, swings (tilts). is there. Since the amount that can be absorbed, that is, the allowable amount is proportional to the inclination angle when the intermediate transmission member that can perform normal drive transmission swings, various methods have been proposed. For example, there is known a method of obtaining an inclination amount of an intermediate transmission member capable of normal drive transmission by providing an appropriate amount of back crushes for respective tooth shapes that mesh with each other. In the present embodiment, as will be described later, a crowning process is performed in which the thickness of the reference circular direction changes in the axial direction along the tooth trace direction to any of the meshed teeth, and meshes with a specified effective tooth surface. It is configured to further increase the allowable amount.

As described above, with the two-stage coupling, an appropriate amount of back crush is provided for each meshing tooth profile, or a crowning process is performed on the meshing tooth profile along the tooth trace direction without causing a rotation transmission error. A shaft misalignment and a shaft deflection angle can be allowed.
More specifically, since there are two meshing portions that allow shaft misalignment and shaft deflection, the external gear 83 and the internal gear portion 84, and the rotating internal gear portion 87 and the external gear portion 86. Even if there is a deviation or a shaft deflection angle, the intermediate transmission member 85 can be permitted by the inclination. Due to such a two-stage coupling, the intermediate transmission member 85 swings in accordance with the shaft misalignment or the shaft deflection angle, and the deviation between the rotation center axis of the external gear 83 and the rotation center axis of the tooth portion 87 in the rotating body. Absorbs. A rotational driving force can be transmitted between two parallel axes that are not on the same straight line without generating an axial reaction force and without changing the angular velocity.

Further, in the photosensitive member drive transmission device 70 of the present embodiment, the drum shaft 50 that is a transmission shaft passes through the photosensitive drum 1 that is a rotating member as described above, and a drum on the rear side of the photosensitive drum 1. A coaxial restriction member 59 that restricts the coaxiality between the shaft 50 and the photosensitive drum 1 is provided.
Specifically, a coaxial regulating member 59 in which a through hole through which the drum shaft 50 passes is formed on the inner side of the photosensitive drum 1 than the rear side flange member 53a fixed to the drum cylinder 52 of the photosensitive drum 1. Is provided. By providing in this way, the photoconductor drum 1, that is, the coaxiality between the drum cylinder 52 of the photoconductor drum 1 and the drum shaft 50 is regulated. Note that, on the front side of the photosensitive drum 1, a through-hole through which the drum shaft 50 passes is formed in the front-side flange member 53b, and the front-side flange member 53b itself performs the same function as the coaxial regulating member 59.

As described above, the coaxial regulating member 59 is provided near the drive source side of the photosensitive drum 1, and the front flange member 53 b that performs the same function is provided on the other end side, so that the photosensitive drum 1 and the drum shaft 50 are coaxial. The degree can be regulated. By regulating in this way, the coaxiality between the photosensitive drum 1 and the drum shaft 50 can be maintained with high accuracy.
Therefore, the intermediate transmission member 85 has a rotational center shift or deviation of the tooth form formed on the external gear 83 press-fitted (fixed) to the drum shaft 50 and the rotating body tooth portion 87 of the rear flange member 53a. Corners (misalignment) can be absorbed with high accuracy. And the rotation transmission error resulting from these can be reduced.
Also, the rigidity of each component member attached to the rotating body is such that the coaxiality between the rotating body and the transmission shaft provided at the end of the rotating body on the drive source side and the rotating shaft provided at the other end is separately regulated. In addition, the coaxiality between the photosensitive drum 1 and the drum shaft 50 can be maintained with high accuracy without increasing the processing accuracy.

Further, the photosensitive drum 1 of this embodiment is one of the units separated from the drive source side unit provided on the copier body 100 side in order to improve the workability at the time of assembly to the copier body 100 or replacement. Offered as a part. That is, the two-stage coupling provided in the photosensitive member drive transmission device 70 of the present embodiment is provided so as to be connected and disconnected.
In the photoreceptor drive transmission device 70 of the present embodiment, the photoreceptor drum 1 is detachably attached to the drum shaft 50.
As described above, by providing the photosensitive drum 1, the copying machine main body in the direction of the rotation center line of the photosensitive drum 1 is improved while improving the workability when the photosensitive member drive transmission device 70 is assembled or the photosensitive drum 1 is replaced. The length of 100 can be shortened.
Next, a configuration for improving the detachability of the photosensitive drum 1 of this embodiment with respect to the drum shaft 50 will be described.

As shown in FIG. 2, the intermediate transmission member 85 has a two-stage structure, and the photosensitive drum 1 has a rear flange member 53a which is an end fixing member fixed to the driving source side end. The rear flange member 53a has a rotating body tooth portion 87.
As described above, by providing the rotating body tooth portion 87 on the rear flange member 53a fixed to the driving source side end portion of the photosensitive drum 1, the photosensitive drum 1 can be assembled or replaced when the photosensitive drum 1 is replaced. Workability can be improved.

  The rear flange member 53 a includes a downstream retaining portion 89 that prevents the intermediate transmission member 85 from falling off downstream in the mounting direction of the photosensitive drum 1 with respect to the drum shaft 50. Have. Then, the external gear portion 86 is configured to be caught by the downstream retaining portion 89 provided at the driving side end portion of the rotating body tooth portion 87. That is, the external gear portion 86 of the intermediate transmission member 85 is prevented from being removed from the rotating body tooth portion 87. By configuring so that it does not come off in this way, it is possible to prevent the intermediate transmission member 85 from dropping off to the downstream side (rear side) in the mounting direction of the photosensitive drum 1 with respect to the drum shaft 50.

And the following effects can be show | played by preventing falling off to the downstream as mentioned above.
It is possible to prevent the intermediate transmission member 85 from falling off when the photosensitive member drive transmission device 70 is assembled or when the photosensitive drum 1 is replaced. Further, work when the photosensitive member drive transmission device 70 is assembled or the photosensitive drum 1 is replaced. Can increase the sex.

Further, in the mounting direction of the photosensitive drum 1 with respect to the drum shaft 50, the teeth at the upstream end (insertion side) tip of the external gear 83 are provided with a taper shape so that the tooth thickness and the tooth depth are reduced. . With such a configuration, the meshing connection with the internal gear portion 84 of the intermediate transmission member 85 is facilitated.
For example, the connection between the external gear 83 and the intermediate transmission member 85 is released, and the phases of the external gear 83 and the internal gear portion 84, and the rotating internal gear portion 87, the intermediate transmission member 85, and the external gear portion 86 are shifted. Even in the case of driving connection from the state, the connection can be made with the correct meshing phase as follows. Due to the change in the posture of the external gear 83 and the intermediate transmission member 85, the backlash between the external gear 83 and the internal gear portion 84, and the backlash between the external gear portion 86 and the rotating internal gear portion 87, the intermediate between the photosensitive drum 1 and the intermediate transmission member 85 is obtained. With a slight rotation of the transmission member 85, the connection can be established with the correct meshing phase.
Even when the attachment / detachment of the photosensitive drum 1 is repeated with respect to the drum shaft 50 that transmits the rotational driving force to the photosensitive drum 1, smooth attachment / detachment can be obtained.

  By transmitting with the correct meshing phase in this way, the intermediate transmission member 85 swings in a state where the internal gear portion 84 and the external gear portion 86 are connected to the external gear 83 and the rotating internal gear portion 87. By absorbing the shaft misalignment and the shaft deflection angle, there is no rotation transmission error, and highly accurate rotation transmission can be realized. In addition, it is possible to suppress the generation of an axial reaction force by connecting the drive unit and the photosensitive unit in a state where an axial deviation or an axial deviation occurs, and to form a highly accurate image. In addition, it is possible to prevent the photoreceptor unit from being unworn and the connecting portion from being damaged due to the contact between the external gear 83 and the internal gear portion 84 during connection from the non-connected state.

Next, the drum shaft 50, the external gear 83, the intermediate transmission member 85, the rotating body tooth portion 87, and the coaxial restriction member 59 will be described in more detail with reference to FIG. Here, FIG. 3 shows a cross section when the drum shaft 50, the external gear 83, the intermediate transmission member 85, the rotating body tooth portion 87, and the coaxial restriction member 59 are assembled.
The external gear 83 press-fitted (fixed) to the drum shaft 50 is formed of sintered metal. Further, in order to obtain the coaxiality between the photosensitive drum 1 and the drum shaft 50, the coaxial regulating member 59 bonded to the drum cylinder 52 of the photosensitive drum 1 and the drum shaft 50 are fitted.

Further, in order for the intermediate transmission member 85 to be inclined more smoothly due to misalignment, the coaxial restriction that contacts the small-diameter cylindrical portion where the internal gear portion 84 of the intermediate transmission member 85 is formed from the rotation center line direction of the photosensitive drum 1. The contact surface of the member 59 is formed in a flat shape without unevenness. Further, the contact surface of the downstream retaining portion 89 provided on the rear flange member 53a that comes into contact with the small diameter cylindrical portion where the external gear portion 86 of the intermediate transmission member 85 is formed from the rotation center line direction of the photosensitive drum 1 is also provided. It is formed in a flat shape without unevenness.
In this way, by making the contact surfaces of the coaxial regulating member 59 and the downstream retaining portion 89 in contact with the intermediate transmission member 85 into a flat surface without unevenness, even when they contact the intermediate transmission member 85 during drive transmission, Occurrence of fluctuations in the rotational speed of the photosensitive drum 1 can be suppressed.

Further, the distance between the contact surfaces of the coaxial regulating member 59 and the downstream retaining portion 89 is provided such that the intermediate transmission member 85 has the following gap in the direction of the rotation center line of the photosensitive drum 1. .
With the photosensitive drum 1 mounted on the drum shaft 50, the meshing of the internal gear portion 84 and the external gear 83 and the meshing of the external gear portion 86 and the rotating internal gear portion 87 are sufficient. It is a gap in the direction of the rotation center line of the photosensitive drum 1.
With this configuration, while maintaining the meshing at the meshing portion where the external gear 83 and the internal gear portion 84 mesh and the meshing portion where the rotating internal gear portion 87 and the external gear portion 86 mesh, The range in which the transmission member 85 can swing can be expanded. Therefore, it is possible to perform high-precision rotation with a wider range of absorption such as an axis deviation and further reduced rotation transmission error.

  As described above, the external gear 83 is a sintered metal, and even with the external gear 83 provided with external teeth having a small diameter, a sufficient rotational driving force can be transmitted and the photosensitive drum 1 can be repeatedly attached and detached. The intermediate transmission member 85 is strong enough not to be damaged by the impact. Further, as described above, the external gear 83 has a tapered portion on the upstream side in the mounting direction of the photosensitive drum 1 with respect to the drum shaft 50, and the internal teeth of the intermediate transmission member 85 are mounted when the photosensitive unit is mounted. The gear portion 84 and the external gear 83 are smoothly engaged with each other. The intermediate transmission member 85 has a two-step (two) cylindrical portion having a step, and is provided with two gear portions, an internal gear portion 84 and an external gear portion 86.

As shown in FIG. 4, the external gear portion 86 has a crowning shape in which the tooth profile is subjected to a crowning process along the tooth trace direction, and meshes with the rotating body tooth portion 87 at the center portion of the tooth width. It has become. Similarly, the internal gear portion 84 has a crowning shape in which the tooth profile is subjected to a crowning process along the tooth trace direction, and is meshed with the external gear 83 at the center portion of the tooth width.
On the other hand, since the external gear 83 is a sintered metal, it is a straight spur gear in which burrs and the like hardly occur on the tooth surface in terms of workability.
The reason why the intermediate transmission member 85 has the two-stage (two) cylindrical portions as described above is to form the above-described internal gear portion 84 into a crowning shape. The inner diameter of the small-diameter cylindrical portion is larger than the diameter of the root circle of the internal gear portion 84.
The formation of the intermediate transmission member 85 will be described in detail later with reference to FIG.

  In the present invention, as described above, each of the internal gear portion 84 and the external gear portion 86 of the intermediate transmission member 85 has a tooth profile in which the thickness in the reference circle direction changes in the axial direction along the tooth line direction. It is designed to be meshed with an effective tooth surface having a predetermined width. By having this crowning-shaped tooth profile in the gear portion, it is possible to allow the shaft deflection angle without generating a rotation transmission error between the external teeth and the internal teeth meshing with each other. The meshing portions that allow the shaft misalignment and the shaft deflection angle are the meshing portion where the external gear 83 and the internal gear portion 84 mesh with each other, and the meshing portion where the rotating internal gear portion 87 and the external gear portion 86 mesh with each other. There are places. Therefore, even if there is a shaft misalignment or a shaft declination, the intermediate transmission member 85 can be permitted by the inclination.

By the two-stage coupling as described above, the intermediate transmission member 85 swings according to the shaft misalignment or the shaft deflection angle, and the rotation center axis of the external gear 83 and the rotation center axis of the rotating body tooth portion 87 Absorb the deviation. A rotational driving force can be transmitted between two parallel axes that are not on the same straight line without generating an axial reaction force and without changing the angular velocity.
In addition, it is possible to increase an allowable amount for an attachment error of the rear flange member 53a with respect to the drum cylinder 52 of the photosensitive drum 1 and an external gear 83 with respect to the drum shaft 50, a processing error of these members, and the like. Therefore, it is possible to avoid an increase in cost in order to reduce these errors and the like, and it is possible to contribute to a reduction in manufacturing cost of the photosensitive member drive transmission device 70.

In addition, in order to obtain a desired amount of inclination of the intermediate transmission member 85, a method of obtaining the amount of inclination of the intermediate transmission member 85 capable of normal drive transmission by providing an appropriate amount of back crushes for the respective tooth shapes that mesh with each other is shown in FIG. The amount of inclination can be obtained only to the extent shown in a). On the other hand, as in the present embodiment, the internal gear portion 84 and the external gear portion 86 are each subjected to a crowning process along the tooth trace direction in a tooth profile whose thickness in the reference circle direction changes in the axial direction. And as shown in FIG.5 (b), the inclination amount of the intermediate | middle transmission member 85 can be enlarged rather than Fig.5 (a).
That is, it is possible to absorb a larger amount of deviation between the rotation center axis of the external gear 83 and the rotation center axis of the rotating body tooth portion 87.

  Further, the intermediate transmission member 85 has meshing portions at two locations on the internal gear portion 84 side and the external gear portion 86 side, but the meshing portion on the internal gear portion 84 side is disposed inside the photosensitive drum 1. Has been. Further, since the meshing portion on the other external gear portion 86 side is arranged on the driving side, the intermediate transmission member 85 is provided in the photosensitive drum 1, so that the rear side main body frame 62 and the rotating internal teeth are provided. The distance of the rear side flange member 53a which has the part 87 can be shortened.

Further, in order to prevent the intermediate transmission member 85 from being detached from the photosensitive drum 1 (the tooth portion 87 in the rotating body), a downstream retaining portion 89 is provided at the driving side end portion of the tooth portion 87 in the rotating body. The photosensitive drum 1 and the intermediate transmission member 85 can be managed as one component. For example, when the rotating body is the photosensitive drum 1 of the copying machine 500 as in this embodiment, the intermediate transmission member 85 can be managed and replaced together when the photosensitive drum 1 is replaced. Body units can be provided.
That is, in the photosensitive member drive transmission device 70 of the present embodiment, the intermediate transmission member 85 is held on the photosensitive drum 1 side when the photosensitive drum 1 is not attached to the drum shaft 50.

  By holding as described above, the rear flange member 53a, the coaxial restriction member 59, and the intermediate transmission member 85 are attached to the drum cylinder 52 of the photosensitive drum 1 before the photosensitive drum 1 is mounted on the drum shaft 50. Can be assembled. Further, the drum cylinder 52, the rear flange member 53a, the coaxial restriction member 59, and the intermediate transmission member 85 of the photosensitive drum 1 can be integrally attached to and detached from the drum shaft 50. Further, workability at the time of assembling the photosensitive member drive transmission device 70 or replacing the photosensitive drum 1 can be further improved.

If the downstream side retaining member 89 is provided in the rear flange member 53a at the driving end of the rotating body tooth portion 87 as described above, the intermediate transmission member 85 can be moved even when the photosensitive drum 1 is assembled. It cannot be inserted or removed from the downstream retaining portion 89 side.
Therefore, in the present embodiment, as described above, the coaxial restriction member 59 is provided on the photosensitive drum 1 as a separate member from the rear flange member 53a. By providing the coaxial regulating member 59 as a separate member in the photosensitive drum 1 in this way, the following effects can be achieved. Even in the configuration having the downstream retaining portion 89 in the rear flange member 53a, the intermediate transmission member 85 can be easily assembled between the downstream retaining portion 89 of the rear flange member 53a and the coaxial regulating member 59. Can do.

  Further, the tooth widths of the external gear 83 and the external gear portion 86 of the present embodiment are 5 [mm]. This is smaller than the tooth width 10 [mm] of the one-stage spline coupling used in the conventional image forming apparatus. The reason why the tooth width can be reduced in this way is that the rotation transmission characteristics tend to be improved by reducing the tooth width, that it can be made in a space-saving layout, and the spline joint has a design philosophy where all teeth mesh. Therefore, there is no problem in durability. Further, in this embodiment, the external gear portion 86 and the internal gear portion 84 having a tooth width of 5 [mm] are subjected to a crowning process, which is known as a structure in which a rotation transmission error is unlikely to occur. A two-stage coupling with high transfer characteristics can be obtained.

  In the above-described embodiment, an example in which the photosensitive drum 1 is a rotating body has been described. However, the photosensitive drum 1 can be used for a connecting portion of a developing roller or a cleaning roller in an image forming unit. The same applies to a stretching roller 12 that is a driving roller that rotationally drives the intermediate transfer belt 5 provided in the image forming apparatus, a fixing roller pair 8 that is provided in the fixing unit, and a secondary transfer roller 7 that is provided in the secondary transfer unit. It can also be used. In particular, when applied to at least one of the developing roller, the developing screw, the photosensitive drum 1, the secondary transfer roller 7, and the stretching roller 12 that is a driving roller for driving the intermediate transfer belt 5, the following is achieved. Can produce various effects. It is possible to reduce a rotation transmission error when a rotational driving force is transmitted to a rotating body related to the image forming process, and it is possible to form a high quality image.

Next, a manufacturing method for molding the intermediate transmission member 85 of the present embodiment by injection molding of a molten resin using a molding die will be described with reference to FIG.
As shown in FIG. 6, the mold 90 includes a fixed upper mold 91 and a movable lower mold 92, and is sandwiched between a gap portion of the upper mold 91 and a gap portion of the lower mold 92. A cavity 95 is formed. The cavity 95 is a gap formed mainly in a cylindrical shape, and the intermediate transmission member 85 that is a cylindrical plastic molded product is formed by injecting molten resin into the cavity 95 and cooling and solidifying. The upper mold 91 is formed with a flow path 93 through which molten resin is supplied and a plurality of pin gates 94 through which the molten resin supplied through the flow path 93 is injected into the cavity 95.

  The upper mold 91 and the lower mold 92 are each formed with a plurality of communication holes 97 that communicate with the cavity 95. These communication holes 97 are connected to a compressed gas supply source 98. The inner diameter of the communication hole 97, more specifically, the inner diameter of the portion of the communication hole 97 that opens to the cavity 95 is 0.001 to 0.5 [mm]. FIG. 5 shows an intermediate transmission member 85 which is a cylindrical plastic molded product formed by a mold 90.

  The cylindrical plastic molded product is composed of the next portion transferred by the cavity 95 of the mold 90. The intermediate transmission member 85 includes two cylindrical portions and an internal gear portion 84 transferred by a tooth shape formed on the inner peripheral side end of the cavity 95 that is the inner peripheral side of the small diameter cylindrical portion. And it is the external gear part 86 transcribe | transferred by the tooth part shape formed in the outer peripheral side edge part of the cavity 95 which is the outer peripheral side of a large diameter cylindrical part.

In this embodiment, in order to form the crowned internal gear portion 84 and the external gear portion 86, a mold 90 having parting lines (mold dividing surfaces) 96a and 96b shown in FIG. 6 is adopted. doing. Here, the crowning shape of the present embodiment is a crowning shape along the tooth trace direction to a tooth shape whose thickness in the reference circle direction changes in the axial direction.
4 described above is an enlarged view of the tooth portion of the external gear portion 86, and shows a crowning shape in which the tooth thickness at the center portion of the tooth width is maximum and the tooth thickness at both ends in the tooth width direction is minimum.

  In order to injection mold the crowning tooth profile as described above, it is necessary to perform mold division at the maximum tooth thickness portion. In other words, the intermediate transmission member 85 having the internal gear portion 84 and the external gear portion 86 is arranged at the center of the tooth width of the tooth profile for forming the parting lines 96a and 96b in the respective tooth profile portions when molding using a mold. There is a need to. By providing the parting lines 96a and 96b in this manner, the intermediate transmission member 85 can be formed by inexpensive injection molding or the like, regardless of the processing method that increases the cost of cutting or the like, and the manufacturing cost of the drive transmission device Can contribute to the reduction of

  Specifically, the mold dividing line 99 in FIG. 4 shows a parting line 96b that is a boundary between the upper mold 91 and the lower mold 92, and half the tooth profile in the tooth width direction of the external gear 86 is connected to the upper mold 91. Transfer molding is performed with each of the lower molds 92. Note that the mold division line of the internal gear portion 84 is 96a, which is a complicated mold division line for molding a crowned tooth profile at one location. For this reason, when the releasability of the cylindrical plastic molded product tends to be low, a slide core is employed for the transfer portion that molds the inside of the small diameter cylindrical portion of the intermediate transmission member 85 and half of the internal gear portion 84. May be.

  Further, as described above, the intermediate transmission member 85 has the two-stage (two) cylindrical portions because the above-described internal gear portion 84 is formed into a crowning shape. The inner diameter of the small-diameter cylindrical portion of the member 85 is larger than the diameter of the root circle of the internal gear portion 84. That is, the root diameter of the inner teeth formed in the internal gear portion 84 is sufficiently smaller than the inner diameter of the cylindrical portion of the intermediate transmission member 85 in which the internal teeth of the internal gear portion 84 are formed. With such a configuration, it is possible to provide a relief step when the mold 90 is used for production, and it is possible to obtain the intermediate transmission member 85 with high processing accuracy.

Next, the procedure at the time of injection molding using the mold 90 of the present embodiment will be described.
At the time of molding a cylindrical plastic molded product, which is performed using the above-described mold 90, the molten resin flows through the flow path 93 and is supplied, and this molten resin is injected from the pin gate 94 into the cavity 95. The molten resin injected into the cavity 95 spreads radially around each pin gate 94. For this reason, variations occur in the timing at which the molten resin injected into the cavity 95 reaches the outer peripheral side end and the inner peripheral side end of the cavity 95. And in the location where the arrival timing of the molten resin is late at the outer peripheral side end and the inner peripheral side end of the cavity 95, the filling amount of the molten resin becomes insufficient.

  The molten resin injected into the cavity 95 is cooled and solidified as time passes. When the resin pressure reaches a predetermined value during the cooling and solidification process, the compressed gas supply source 98 is driven. By driving the compressed gas supply source 98 in this way, it is formed into the cavity 95 from the communication hole 97 formed facing the side surface portion of the small diameter cylindrical portion, and opposed to the end surface portion of the large diameter cylindrical portion. The compressed gas is blown into the cavity 95 from the communicating hole 97. By blowing this compressed gas, a drawing recess is formed in the side surface portion of the small diameter cylindrical portion and the portion formed facing the communication hole 97 in the end surface portion of the large diameter cylindrical portion. By forming such a recess recess, an amount of molten resin corresponding to the volume of the formed recess recess is additionally filled at the outer peripheral end and inner peripheral end of the cavity 95. .

In addition, the position where this close recess is formed is the substantially central portion of two adjacent pin gates. And it is also a position corresponding to the location where the molten resin injected into the cavity 95 arrives at the outer peripheral side end or the inner peripheral side end of the cavity 95 and the molten resin filling amount is insufficient. Therefore, it will be in the state where the molten resin is additionally filled in a portion where the amount of the molten resin is insufficient. Thereby, the variation of the filling amount of the molten resin with which the outer peripheral side end part and inner peripheral side end part of the cavity 95 are filled can be corrected and made substantially uniform.
Therefore, it is possible to prevent occurrence of corrugated irregularities in the tooth shape of the internal gear portion 84 and the external gear portion 86 of the inner peripheral transfer portion of the two cylindrical portions, and to provide a gear portion (tooth profile) with high molding accuracy. The intermediate transmission member 85 which is a cylindrical plastic molded product can be obtained.

It should be noted that by adjusting the driving timing and output of the compressed gas supply source 98, the amount and timing of applying compressed gas can be adjusted as appropriate, thereby adjusting the formation region and depth of the recess recess. Can do. For this reason, the volume of the recess recess can be adjusted, and the amount of the molten resin that is additionally filled in the outer peripheral side end and the inner peripheral side end of the cavity 95 can be adjusted. By this adjustment, it is possible to more reliably prevent the occurrence of wavy irregularities in the internal gear portion 84 and the external gear portion 86 of the inner peripheral transfer portion of the two cylindrical portions, and a cylinder with higher tooth profile molding accuracy. An intermediate transmission member 85 that is a plastic molded product can be obtained.
Further, since the inner diameter of the communication hole 97 is as small as 0.001 to 0.5 [mm], the molten resin injected into the cavity 95 does not enter the communication hole 97 and the molten resin does not enter the communication hole 97. Generation of burrs caused by entering the inside is prevented.

(Example 2)
Example 2 of the photoconductor drive transmission device 70 which is a drive transmission device provided in the photoconductor drive device 10 of this embodiment will be described with reference to the drawings.
FIG. 7 is an explanatory diagram of the photosensitive member drive transmission device 70 and the photosensitive drum 1 according to the present embodiment. FIG. 8 is a drive connecting portion provided in the photosensitive member drive transmission device 70 according to the present embodiment, and the photosensitive member. 2 is an explanatory diagram of a drum 1. FIG.

The photosensitive member drive transmission device according to the first embodiment and the photosensitive member drive transmission device 70 according to the present embodiment are different in the following configuration.
The gear change mechanism provided in the drive unit uses a gear train in the first embodiment, whereas the planet gear reduction device 30 that is a planetary gear mechanism is used in the present embodiment. Is a point. Further, the intermediate transmission member 85 is held in the state where the photosensitive drum 1 as the rotating body is not attached to the drum shaft 50 as the transmission shaft, although it was on the photosensitive drum 1 side in the first embodiment. In contrast, in this embodiment, the drum shaft 50 is used.
Therefore, the configuration similar to that of the above-described first embodiment and the operations and effects thereof will be omitted as appropriate.

As shown in FIG. 7, in the photoreceptor drive transmission device 70 of this embodiment, as a speed change mechanism that decelerates the rotational driving force from the drive motor 20 that is a drive source and transmits it to the photoreceptor drum 1 that is a rotor. A planetary gear reduction device 30 is provided on the drive unit side.
Conventionally, when a large number of parts such as a planetary gear mechanism is used on the drive unit side as described above, the shaft reaction force generated by the connecting means affects the gear engagement state on the drive unit side. In some cases, however, the degradation of image quality tends to increase.
Hereinafter, regarding the photosensitive member drive transmission device 70 of the present embodiment, the configuration of the driving unit and the photosensitive member unit different from those of the first embodiment will be described.

  As shown in FIG. 7, the photoconductor driving device 10 of the present embodiment includes a drive motor 20, a planetary gear reduction device 30, a joint 41, a drum shaft 50, an external gear 83 (spline coupling input unit), and the like. Yes. The output shaft 40 of the planetary gear reduction device 30 is connected and fixed by a drum shaft 50 and a joint 41. A bearing 51b is press-fitted on the rear side of the drum shaft 50, and is supported and positioned on the rear side main body frame 62 of the copying machine main body 100 via the bearing 51b, and is fixed after the photosensitive drum 1 is mounted. The mounting surface plate 61a is supported by the bearing.

Next, the details of the internal structure of the planetary gear reduction device 30 will be described.
The planetary gear reduction device 30 of the present embodiment uses a 2K-H type two-stage planetary gear mechanism. In the configuration shown in FIG. 7, the number of stages is two, but it is also possible to further superimpose the number of stages with three stages and four stages according to the reduction ratio.
The first sun gear 31 of the planetary gear reduction device 30 is provided by directly cutting the motor output shaft 21 of the drive motor 20. The first stage first planetary gear 33 meshing with the first sun gear 31 and the internal gear 32 fixed to the internal gear fixing flange 22 is supported by the first carrier 34 of the first stage, and The outer periphery is revolved.

The first planetary gear 33 is concentrically arranged at three locations for rotational balance and torque sharing. Each first planetary gear 33 is supported by a first carrier pin 35 provided on the first carrier 34 and rotates.
The first planetary gear 33 rotates and revolves due to the engagement of the first sun gear 31 and the internal gear 32, and the first carrier 34 that supports the first planetary gear 33 rotates the first sun gear 31. The first reduction gear ratio is obtained.
Next, the second sun gear 36 provided at the rotation center of the first carrier 34 becomes an input of the second stage reduction mechanism. The first carrier 34 does not have a rotation support portion, and performs floating rotation. Similarly, the second stage second sun gear 36 is supported by a second stage second carrier 38 with a second stage second planetary gear 37 meshing with the internal gear 32 integrally formed up to the second stage. Thus, the outer periphery of the second sun gear 36 in the second stage is revolved.

  Each second planetary gear 37 rotates and revolves while being supported by a second carrier pin 39 provided on the second carrier 38. An output shaft 40 is provided at the center of rotation of the second carrier 38 in the second stage corresponding to the final stage, and is connected to the drum shaft 50 via a joint 41 on a hollow cylinder. Here, the output shaft 40 of the second carrier 38 is supported by a bearing 51 a press-fitted into an internal gear cap 42 positioned by the internal gear 32. Since the internal gear cap 42 is positioned by the inner circumference and the inlay of the internal gear 32, the output shaft 40 is configured to minimize the coaxiality with the central axis of the internal gear.

The joint 41 has a hollow cylindrical shape, and the drum shaft 50 and the output shaft 40 of the planetary gear reduction device 30 have the same diameter. The joint 41 is press-fitted into the drum shaft 50, the joint 41 has a slit 41a at the center, and the output shaft 40 is connected by a frictional force with the joint 41 pushed and bent by a fixing screw (not shown). It has a fixed configuration.
The motor output shaft 21 of the drive motor 20 described above is supported by an internal tooth fixing flange 22. The internal gear 32 is fixed to the internal gear fixing flange 22 with screws 43, and the internal gear fixing flange 22 fixes and holds the internal gear 32 and fixes and holds the drive motor 20.

The internal tooth fixing flange 22 is fixed to the drive frame 63 with screws. The drive frame 63 is supported and positioned by a stud 64 that is crimped to the rear side main body frame 62.
On the drive source side of the internal gear 32, a hollow cylindrical boss is provided on the central axis of the internal gear 32. The drive motor 20 is positioned by fitting a cylindrical inner periphery and a bearing provided on the motor output shaft 21 side with a spigot, and the hollow cylindrical outer periphery is positioned by a fitting with a hole of the internal tooth fixing flange 22 and a spigot. It is the composition which becomes.

With the above configuration, the central axis of the motor output shaft 21, the internal gear fixing flange 22, and the output shaft 40 of the planetary gear reduction device are all coaxially arranged with reference to the internal gear 32, and the parts The coaxiality due to dimensional variation can be minimized. As a result, all the central axes from the motor output shaft 21 to the drum shaft 50 can be coaxially arranged, and the coaxiality due to variations in component dimensions can be minimized.
In addition, the speed detection means 44 is provided on the same axis as the central axis of the internal gear 32, the motor output shaft 21, the internal gear fixing flange 22, and the output shaft 40 of the planetary gear reduction device 30.
In this embodiment, an encoder and a two-sensor configuration are used as the speed detection means 44. In this configuration, the number of sensors may be arbitrarily changed depending on the required control accuracy.

The photosensitive drum 1 as a rotating body is positioned on the drum shaft 50 via a rear flange member 53a and a front flange member 53b provided at both ends thereof. The rear flange member 53a is integrally formed with a rotating body tooth portion 87 of an internal tooth that is a rotating body tooth portion. The rear flange member 53a in which the rotating body tooth portion 87 is formed is integrally provided with a coaxial restriction member 59 which is a coaxial restriction member having a through hole through which the drum shaft 50 passes at the center of rotation. The through hole and the drum shaft 50 are positioned by the inlay.
Thus, by providing the coaxial regulating member 59 integrally with the rear flange member 53a, the function of maintaining the coaxiality between the photosensitive drum 1 and the drum shaft 50 and the rotational driving force are transmitted to the photosensitive drum 1. The number of members can be reduced by giving the function to one member. Accordingly, it is possible to reduce the manufacturing process of the photosensitive member drive transmission device 70 by reducing processing steps and work steps.

  The drum shaft 50 is press-fitted with an external gear 83 that is a shaft external gear member that transmits drive to the photosensitive drum 1. And the internal gear part 84 and the external gear 83 which are the intermediate internal gear parts of the intermediate transmission member 85, the external gear part 86 which is the intermediate external gear part of the intermediate transmission member 85, and the rear side flange member 53a. The photosensitive drum 1 is driven through each meshing portion of the tooth portion 87.

With the above configuration, the motor output shaft 21, the internal gear 32, the second carrier 38, the output shaft 40 of the planetary gear reduction device 30, the drum shaft 50, the central axis of the photosensitive drum 1, and the rotation center are all the same axis. It is arranged on the top so that the coaxiality can be minimized.
However, the shaft that is the rotational center deviation of the internal gear portion 84 of the intermediate transmission member 85 with respect to the external gear 83 and the rotating internal gear portion 87 with respect to the external gear portion 86 due to the following decrease in assembly accuracy and processing accuracy. Deviation and shaft deflection may occur. The precision of press-fitting the rear flange member 53a and the front flange member 53b into the drum cylinder 52, the molding accuracy of the rotating body tooth 87 integrated with the rear flange member 53a, the molding accuracy of the external gear 83, and the drum shaft 50 Press-fit accuracy.
However, in the photoreceptor drive transmission device 70 of the present embodiment, the above-described shaft misalignment and shaft deflection angle are absorbed by the swing of the intermediate transmission member 85 that constitutes the two-stage coupling, thereby realizing highly accurate rotation transmission. it can.
The photosensitive member drive transmission device 70 of this embodiment has a larger number of parts when removing the intermediate transmission member 85 than the first embodiment, but it is easy to disassemble, so that it can be easily assembled (when assembled). There is an advantage that it is excellent in workability.

Next, referring to FIG. 8, the drum shaft 50, the external gear 83, the intermediate transmission member 85, the upstream retaining member 71 that is the upstream retaining member, and the downstream retaining member that are characteristic portions of the present embodiment. The downstream retaining member 73 and the rear flange member 53a, which are members, will be described.
The intermediate transmission member 85 has meshing portions at two locations on the internal gear portion 84 side and the external gear portion 86 side, and the meshing portion where the external gear 83 and the internal gear portion 84 are meshed is the photosensitive drum 1. Arranged inside. The other meshing portion where the rotating internal gear portion 87 and the external gear portion 86 mesh with each other is disposed on the drive source side of the photosensitive drum 1. With these configurations, in the photoreceptor drive transmission device 70 of the present embodiment, the intermediate transmission member 85 is provided in the photoreceptor drum 1 as in the first embodiment, and the rear side main body frame 62 and the rotating body tooth portion 87 are provided. The distance of the rear side flange member 53a can be shortened.

  Further, in order to obtain the coaxiality between the photosensitive drum 1 and the drum shaft 50, a rear side flange member 53a integrally provided with a coaxial regulating member 59 having a through hole in which the drum shaft 50 is positioned by an inlay is provided as a photosensitive member. A drum cylinder 52 of the drum 1 is fixed. The through hole of the coaxial regulating member 59 and the drum shaft 50 are fitted, but the input meshing portion on the internal gear portion 84 side is in the photosensitive drum 1 to be coaxial with the rear flange member 53a. A single member can be provided with two functions of accuracy improvement and rotational drive transmission. In addition, since the tooth width of the rotating internal tooth portion 87 with which the external gear 83 meshes can be shortened to a necessary minimum amount, the gear accuracy can be easily obtained in the molding process.

  Further, in order to prevent the intermediate transmission member 85 from falling off the drum shaft 50, the upstream retaining member 71 is disposed upstream and downstream of the external gear 83 in the mounting direction of the photosensitive drum 1 with respect to the drum shaft 50. And a downstream retaining member 73. The upstream retaining member 71 is moved upstream by an upstream retaining member 72 provided on the drum shaft 50 closest to the upstream side, and the downstream retaining member 73 is provided on the drum shaft 50 closest to the downstream side. Further, the downstream side stop member 74 is restricted from moving downstream. With this configuration, it is possible to prevent the intermediate transmission member 85 from falling off when the photosensitive member drive transmission device 70 is assembled or when the photosensitive drum 1 is replaced, and when the photosensitive member drive transmission device 70 is assembled or the photosensitive member. The workability at the time of exchanging the drum 1 can be further improved.

Similarly to the first embodiment, the intermediate transmission member 85 has two cylindrical portions with different outer diameters, and the internal teeth of the internal gear portion 84 are formed on the inner periphery of the small-diameter cylindrical portion on the side having the smaller outer diameter. The external teeth of the external gear portion 86 are formed on the outer periphery of the large-diameter cylindrical portion that is formed and has a larger outer diameter.
Each retaining member is configured as follows to achieve its function. The outer peripheral diameter of the upstream retaining member 71 is larger than the root circle diameter of the internal gear portion 84, and the outer peripheral diameter of the downstream retaining member 73 is larger than the tooth tip circular diameter of the internal gear portion 84, and the smaller diameter side. It is smaller than the inner diameter of the tube portion. With this configuration, even in the configuration having the upstream retaining member 71 and the downstream retaining member 73, the downstream retaining member 73 can be disposed within the small diameter cylindrical portion of the intermediate transmission member 85, and the photosensitive drum 1. The length of the copying machine main body 100 in the rotation center line direction can be shortened.

  In addition, the upstream retaining member 71 and the downstream retaining member 73 are formed in a flat surface with no irregularities on the surface in contact with the intermediate transmission member 85. In this way, the contact surfaces of the retaining members that contact the intermediate transmission member 85 are made flat without any irregularities, so that the rotational speed of the photosensitive drum 1 can be achieved even when they contact the intermediate transmission member 85 during drive transmission. The occurrence of fluctuation can be suppressed.

By configuring as described above, the drum shaft 50 and the intermediate transmission member 85 can be managed as one component. Therefore, when the rotating body is the photosensitive drum 1 of the copying machine 500 as in this embodiment, the intermediate transmission member 85 is moved to the drum shaft 50 side when the photosensitive body drive transmission device 70 is assembled or when the photosensitive drum 1 is replaced. Retained.
For this reason, since the photosensitive drum 1 that is a drum component can be managed by a single photosensitive drum 1 as in the past, a photosensitive unit excellent in serviceability while maintaining misalignment absorption capability at the same transportation cost as before. Can be provided.
Further, before the photosensitive drum 1 is mounted on the drum shaft 50, the intermediate transmission member 85 is assembled to the drum shaft 50, or the intermediate transmission member 85 and the drum shaft 50 are integrally attached to and detached from the copying machine main body 100. Can do. Therefore, the workability at the time of assembling the photosensitive member drive transmission device 70 or replacing the photosensitive drum 1 can be further enhanced.

Similarly to the first embodiment, of the external teeth provided on the external gear portion 86 and the external gear 83 of the intermediate transmission member 85, external teeth that mesh when the photosensitive drum 1 is mounted on the drum shaft 50. Alternatively, a tapered shape can be provided on the upstream side in the mounting direction of the photosensitive drum 1 with respect to the drum shaft 50.
By providing the taper shape in this manner, smooth detachability can be obtained even when the detachment of the photosensitive drum 1 is repeated with respect to the drum shaft 50 that transmits the rotational driving force to the photosensitive drum 1.

In the above-described embodiment, the photosensitive drum 1 that is a rotating body is detachable from the drum shaft 50 that is a transmission shaft that penetrates the photosensitive drum 1, that is, the rotating body is attached to the apparatus main body such as the copying machine main body 100. An example in which the present invention is applied to a configuration that is detachably provided has been described. However, the present invention is not limited to such a configuration.
For example, the present invention can also be applied to a drive transmission device in which a rotating body is not attached to or detached from the apparatus main body after delivery to a user or business office. By applying the present invention to such a drive transmission device, it is possible to provide a drive transmission device in which the length in the direction of the center line can be made shorter than before. Also, when assembling the drive transmission device, by applying the present invention, it is possible to improve workability when assembling.

Further, although the example in which the present invention is applied to the configuration including the transmission shaft such as the drum shaft 50 that passes through the photosensitive drum 1 that is the rotating body has been described, the present invention is not limited to such a configuration. .
For example, the present invention can also be applied to a drive transmission device including a transmission shaft on the drive source side that is one end side of the rotating body and a rotating shaft that supports the other end side of the rotating body. By applying the present invention to such a drive transmission device, it is possible to provide a drive transmission device in which the length in the direction of the center line can be made shorter than before. Further, since the transmission shaft does not penetrate the rotating body, the workability at the time of assembling can be further improved by applying the present invention also when assembling the drive transmission device.
However, depending on the size, length, and rigidity of the rotating body, and the rigidity of the end fixing member such as the flange member and the coaxial regulating member, the degree of coaxiality between the rotating shaft and transmission shaft on the other end side and the rotating body It may be necessary to provide a separate configuration for maintaining the above.

Further, the present invention is applied to a configuration in which a coaxial regulating member 59 that is a coaxial regulating member that maintains the coaxiality between the photosensitive drum 1 that is a rotating body and the drum shaft 50 that is a transmission shaft is provided inside the photosensitive drum 1. However, the present invention is not limited to such a configuration.
For example, the present invention can also be applied to a drive transmission device including a coaxial regulating member that contacts at least one end of the rotating body from the inner or outer peripheral side of the rotating body or the flange member and rotatably supports the rotating body. Even if the present invention is applied to such a drive transmission device, it is possible to provide a drive transmission device in which the length in the center line direction can be made shorter than that of a conventional drive transmission device having the same configuration.
However, with the coaxial restriction member, the space in the direction perpendicular to the rotation center line direction for restricting the coaxiality between the rotary body and the rotary shaft from the inner peripheral side or the outer peripheral side of the rotary body or the flange member increases or rotates. It may be necessary to increase the machining accuracy of the shaft and the like, which may increase the cost.

Further, the rotational driving force of the drive motor 20 that is a dedicated drive source is applied to the photosensitive drum 1 that is a rotating body via a planetary gear speed reduction device 30 that is a planetary gear mechanism on the drive source side and a transmission mechanism that uses a gear train. An example in which the present invention is applied to a configuration for transmitting the above has been described. However, the present invention is not limited to such a configuration.
For example, the present invention can be applied to a drive transmission device that uses a direct drive drive source such as a motor capable of high-precision rotation and rotationally drives a rotating body without using a speed change mechanism.
However, since the direct drive motor capable of high-precision rotation is expensive and large in size, there is a risk of increasing the cost and the size of the drive source.
The present invention can also be applied to a drive transmission device that transmits a rotational driving force to another rotating body, and a drive transmission device that is drivingly connected using a gear train, a timing belt, or the like and does not include a dedicated drive source.

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 the drive transmission device such as the photosensitive member drive transmission device 70 having an intermediate transmission member such as the intermediate transmission member 85 in the drive transmission path between the drive source such as the drive motor 20 and the rotating body such as the photosensitive drum 1, A transmission shaft such as a drum shaft 50 that transmits a rotational driving force to the rotating body, and an external shaft tooth member such as an external gear 83 that is fixed to the transmission shaft. Both of the intermediate transmission members have a tooth profile center. An intermediate internal tooth portion such as an internal gear portion 84 formed with internal teeth and an intermediate external tooth portion such as an external gear portion 86 formed with external teeth, which are on the same straight line, A tooth part meshes with a rotating body tooth part such as the rotating tooth part 87 of the rotating tooth, and an intermediate external tooth part of the internal tooth provided on the rotating body. The rotating body such as the driving source side end of the outer periphery of the rear side flange member 53a The rotary body side than the driving source side end portion of the outer periphery, is characterized in that at least one of the said intermediate inner teeth portion intermediate outer teeth are provided.

According to this, as described in the first embodiment (or 2), the following effects can be obtained.
Unlike the conventional configuration in which the entire intermediate transmission member is located closer to the drive source side in the rotation center line direction of the rotating body than the end portion on the outer periphery of the rotating body, at least one of the intermediate inner tooth portion and the intermediate outer tooth portion However, it is provided inside the rotating body from the drive source side end of the outer periphery of the rotating body. For this reason, the distance required from the drive source side end of the outer periphery of the rotating body in the direction of the rotation center line of the rotating body to provide the intermediate transmission member can be shortened compared to the conventional configuration. Become. Therefore, the length of the apparatus main body such as the copying machine main body 100 in the rotation center line direction of the rotating body can be made shorter than that of the conventional configuration.
Therefore, it is possible to provide a drive transmission device that includes an intermediate transmission member in the drive transmission path between the drive source and the rotator, and that can shorten the length of the device body in the direction of the rotation center line of the rotator.

(Aspect B)
In (Aspect A), the intermediate internal gear portion such as the internal gear portion 84 is closer to the rotation center line direction of the rotating body such as the photosensitive drum 1 than the intermediate external gear portion such as the external gear portion 86. It is provided inside the rotating body.
According to this, as described in the first embodiment (or 2), the following effects can be obtained.
The intermediate internal gear portion that meshes with the shaft external gear member such as the external gear 83 is more reliably rotated than the drive source side end portion of the outer periphery of the rotary body such as the drive source side end portion of the outer periphery of the rear flange member 53a. Can be provided inside the rotating body in the direction of the rotation center line.
Therefore, in order to provide an intermediate transmission member such as the intermediate transmission member 85, the distance required from the drive source side end of the outer periphery of the rotating body in the direction of the rotation center line of the rotating body to the drive source side is larger than that of the conventional configuration. It becomes possible to shorten it reliably.

(Aspect C)
In (Aspect B), the driving source side end of the rotating body tooth portion such as the rotating body tooth portion 87 drives the outer periphery of the rear flange member 53a in the direction of the rotation center line of the rotating body such as the photosensitive drum 1. Provided at the same position as the drive source side end of the outer periphery of the rotating body, such as the source side end, on the inner side of the rotating body or at the outer periphery of the rotating body, the intermediate transmission member 85, etc. The intermediate transmission member has a reference circle diameter of the external teeth of the intermediate external tooth portion such as the external gear portion 86 larger than a reference circular diameter of the internal teeth of the intermediate internal gear portion such as the internal gear portion 84. It is a feature.

According to this, as described in the first embodiment (or 2), the following effects can be obtained.
The drive-source-side end of the rotating body tooth is provided at the same position as the drive-source-side end of the outer periphery of the rotating body or the outer periphery of the rotating body. For this reason, it is possible to reliably provide a part of the intermediate transmission member on the inner side of the rotating body in the direction of the rotation center line of the rotating body than the end on the drive source side of the outer periphery of the rotating body. Since the intermediate internal tooth portion is provided on the inner side of the rotating body in the rotation center line direction of the rotating body than the rotating body tooth portion, most of the intermediate transmission member is located on the rotating body on the outer side of the rotating body than on the driving source side end. It can be provided inside the rotating body in the rotation center line direction.

Moreover, the reference | standard circle diameter of the external tooth of an intermediate | middle external tooth part is larger than the internal tooth of an intermediate | middle internal tooth part. Thereby, it is possible to easily provide a meshing portion in which the externally toothed member such as the external gear 83 meshes with the intermediate internal gear portion on the inner side of the rotating body than the meshing portion in which the internal tooth portion of the rotating body meshes with the intermediate external gear portion. it can.
Therefore, in providing the intermediate transmission member, the distance required from the drive source side end of the outer periphery of the rotating body in the direction of the rotation center line of the rotating body to the drive source side can be greatly and easily compared to the conventional configuration. It can be shortened.

(Aspect D)
In any one of (Aspect A) to (Aspect C), a coaxial restriction member such as a coaxial restriction member 59 that restricts the degree of coaxiality between the rotating body such as the photosensitive drum 1 and the transmission shaft such as the drum shaft 50 is provided. It is provided in a rotating body, the transmission shaft penetrates the rotating body, and the rotating body is provided so as to be detachable from the transmission shaft.

According to this, as described in the first embodiment (or 2), the following effects can be obtained.
A coaxial regulating member is provided in the vicinity of the drive source side of the rotator, and an other end side fixed member such as a front flange member 53b that performs the same function is provided on the other end side so that the rotator and the transmission shaft are coaxial. The degree of rotation can be regulated, and the coaxiality between the rotating body and the transmission shaft can be maintained with high accuracy.
Therefore, the intermediate transmission member such as the intermediate transmission member 85 can accurately absorb the misalignment or misalignment of the rotation center of the tooth profile of the following members, and reduce the rotation transmission error caused by them. can do. It is formed in a rotating internal tooth portion such as a rotating internal tooth portion 87 provided on a shaft external tooth member such as an external gear 83 fixed to the transmission shaft and a driving source side end fixing member such as a rear flange member 53a. Misalignment of the rotation center of the tooth profile, declination, and the like.

Also, the rigidity of each component member attached to the rotating body is such that the coaxiality between the rotating body and the transmission shaft provided at the end of the rotating body on the drive source side and the rotating shaft provided at the other end is separately regulated. In addition, the coaxiality between the rotating body and the transmission shaft can be maintained with high accuracy without increasing the processing accuracy.
Further, by providing the rotating body so as to be detachable from the transmission shaft, the rotation center line of the rotating body can be improved while improving the workability at the time of assembling a drive transmission device such as the photosensitive member drive transmission device 70 or replacing the rotating body. The length of the apparatus main body such as the copying machine main body 100 in the direction can be shortened.

(Aspect E)
In (Aspect D), the rotating body such as the photosensitive drum 1 is fixed to the driving source side end, and the end of the rear flange member 53a and the like having the rotating body tooth portion such as the rotating body tooth portion 87 is provided. It is characterized by comprising a part fixing member.
According to this, as described in the first embodiment (or 2) described above, the rotating body tooth portion is provided on the end fixing member fixed to the driving source side end portion of the rotating body, whereby the rotating body is provided. The workability at the time of assembly and replacement of the rotating body can be improved.

(Aspect F)
In (Embodiment E), in a state where the rotating body such as the photosensitive drum 1 is not attached to the transmission shaft such as the drum shaft 50, the intermediate transmission member such as the intermediate transmission member 85 is held on the rotating body side. It is characterized by this.
According to this, as described in the first embodiment, the following effects can be obtained.
Prior to mounting the rotating body on the transmission shaft, the end fixing member such as the rear flange member 53a, the coaxial regulating member such as the coaxial regulating member 59, and the intermediate transmission member can be assembled to the rotating body. Further, the rotating body, the end fixing member, the coaxial regulating member, and the intermediate transmitting member can be integrally attached to and detached from the transmission shaft, and when the drive transmission device such as the photosensitive member drive transmission device 70 is assembled or the rotating body. The workability at the time of replacement can be further improved.

(Aspect G)
In (Aspect F), the end fixing member such as the rear flange member 53a is the transmission shaft such as the drum shaft 50 of the rotating body such as the photosensitive drum 1 where the intermediate transmission member such as the intermediate transmission member 85 is the intermediate transmission member. A downstream side retaining portion such as a downstream side retaining portion 89 that prevents falling off in the downstream direction in the mounting direction is provided downstream of the rotating body tooth portion such as the rotating body tooth portion 87. It is what.
According to this, as described in the first embodiment, it is possible to prevent the intermediate transmission member from dropping off when the drive transmission device such as the photosensitive member drive transmission device 70 is assembled or when the rotating body is replaced. Workability at the time of assembling the transmission device or replacing the rotating body can be improved.

(Aspect H)
In (Aspect G), the coaxial restriction member such as the coaxial restriction member 59 is provided in the rotating body such as the photosensitive drum 1 as a separate member from the end fixing member such as the rear flange member 53a. It is characterized by being.
According to this, as described in the first embodiment, the following effects can be obtained.
Even in a configuration in which the downstream retaining portion such as the downstream retaining portion 89 is provided in the end fixing member, the intermediate transmission member 85 or the like is provided between the downstream retaining portion of the end fixing member and the coaxial regulating member. The intermediate transmission member can be easily assembled.

(Aspect I)
In (Embodiment E), in a state where the rotating body such as the photosensitive drum 1 is not attached to the transmission shaft such as the drum shaft 50, the intermediate transmission member such as the intermediate transmission member 85 is held on the transmission shaft side. It is characterized by that.
According to this, as described in the second embodiment, the following effects can be obtained.
Before attaching the rotating body to the transmission shaft, the intermediate transmission member can be assembled to the transmission shaft, or the intermediate transmission member and the transmission shaft can be integrally attached to and detached from the apparatus main body such as the copying machine main body 100. Therefore, the workability when assembling a drive transmission device such as the photosensitive member drive transmission device 70 or replacing the rotating body can be further enhanced.

(Aspect J)
In (Aspect I), intermediate transmission members are provided on the upstream side and the downstream side of the shaft external gear member such as the external gear 83 in the mounting direction of the rotating body such as the photosensitive drum 1 with respect to the transmission shaft such as the drum shaft 50. An upstream retaining member such as an upstream retaining member 71 that prevents the intermediate transmission member such as 85 from falling off and a downstream retaining member such as a downstream retaining member 73 are provided. It is.
According to this, as described in the above-described second embodiment, it is possible to prevent the intermediate transmission member from falling off when the drive transmission device such as the photosensitive member drive transmission device 70 is assembled or when the rotating body is replaced. The workability at the time of assembling the device or replacing the rotating body can be further enhanced.

(Aspect K)
In (Aspect J), the intermediate transmission member such as the intermediate transmission member 85 has two cylindrical portions with different outer peripheral diameters, and an internal gear portion 84 and the like on the inner periphery of the small-diameter cylindrical portion on the side with the smaller outer peripheral diameter. The internal teeth of the intermediate internal tooth portion are formed, and the external teeth of the intermediate external tooth portion such as the external gear portion 86 are formed on the outer periphery of the large-diameter cylindrical portion on the side of the larger outer diameter. The upstream retaining member such as the retaining member 71 has an outer peripheral diameter larger than the diameter of the tip of the inner tooth of the intermediate inner tooth portion, and the downstream retaining member such as the downstream retaining member 73 is The outer peripheral diameter is smaller than the inner diameter of the small-diameter cylindrical portion, and larger than the diameter of the tip circle of the inner tooth of the intermediate inner tooth portion.
According to this, as described in the second embodiment, the following effects can be obtained.
Even in the configuration having the upstream retaining member and the downstream retaining member, the downstream retaining member can be disposed in the small-diameter cylindrical portion of the intermediate transmission member, and the copying machine in the direction of the rotation center line of the rotating body such as the photosensitive drum 1 The length of the apparatus main body such as the main body 100 can be shortened.

(Aspect L)
In any one of (Aspect I) to (Aspect K), the end fixing member such as the rear flange member 53a is integrally provided with the coaxial restriction member such as the coaxial restriction member 59. To do.
According to this, as described in the second embodiment, the function of maintaining the coaxiality between the rotating body such as the photosensitive drum 1 and the transmission shaft such as the drum shaft 50 and the rotational driving force are transmitted to the rotating body. The number of members can be reduced by giving one member the function to do this. Therefore, it is possible to reduce the manufacturing cost of the drive transmission device such as the photosensitive member drive transmission device 70 by reducing processing steps and work steps.

(Aspect M)
In any one of (Aspect A) to (Aspect L), the intermediate transmission member such as the intermediate transmission member 85 includes the intermediate external teeth such as the internal gear portion 84 and the external external gear portion 86. The tooth profile of the part is subjected to a crowning process along the tooth trace direction.
According to this, as described in the first embodiment (or 2), the following effects can be obtained.
Mounting errors such as an end fixing member such as a rear flange member 53a with respect to a rotating body such as the photosensitive drum 1, an external gear member such as an external gear 83 with respect to a transmission shaft such as the drum shaft 50, and the like. The tolerance for machining errors and the like can be increased. Therefore, it is possible to avoid an increase in cost in order to reduce these errors and the like, and it is possible to contribute to a reduction in manufacturing cost of a drive transmission device such as the photosensitive member drive transmission device 70.

(Aspect N)
In any one of (Aspect E) to (Aspect M), the intermediate external tooth portion such as the external gear portion 86 of the intermediate transmission member such as the intermediate transmission member 85 and the shaft external tooth member such as the external gear 83 are used. Out of the provided external teeth, the external teeth meshing when the rotating body such as the photosensitive drum 1 is mounted on the transmission shaft such as the drum shaft 50, the upstream side in the mounting direction of the rotating body with respect to the transmission shaft. Is provided with a taper shape.
According to this, as described in the first embodiment (or 2), smooth detachability is obtained even when the rotator is repeatedly attached to and detached from the transmission shaft that transmits the rotational driving force to the rotator. be able to.

(Aspect O)
In any one of (Aspect A) to (Aspect N), a member such as a coaxial regulating member 59 that contacts the intermediate transmission member such as the intermediate transmission member 85 from the rotation center line direction of the rotating body such as the photosensitive drum 1. The contact surface is formed in a flat shape.
According to this, as described in the first embodiment (or 2), the following effects can be obtained.
By making the contact surfaces of each retaining member that contacts the intermediate transmission member, the downstream retaining portion such as the downstream retaining portion 89, and the coaxial regulating member into a flat surface without irregularities, these can be transmitted intermediately during drive transmission. Even when it contacts with a member, generation | occurrence | production of the rotational speed fluctuation | variation of a rotary body can be suppressed.

(Aspect P)
In any one of (Aspect A) to (Aspect O), the shaft external gear member such as the external gear 83 is formed by sintering, and is press-fitted into the transmission shaft such as the drum shaft 50 and is fitted. It is characterized by being.
According to this, as described in the first embodiment (or 2), the following effects can be obtained.
Even an off-axis tooth member provided with a small-diameter external tooth can transmit a sufficient rotational driving force, and is also damaged by the impact of the intermediate transmission member 85 due to repeated attachment and detachment of a rotating body such as the photosensitive drum 1. It can be strong enough not to.

(Aspect Q)
In any one of (Aspect M) to (Aspect P), the intermediate transmission such as the intermediate transmission member 85 including the intermediate internal tooth portion such as the internal gear portion 84 and the intermediate external tooth portion such as the external gear portion 86. In the case where the member is molded using a mold, the parting line is at the center of the tooth width of the tooth profile to be molded in each tooth profile part.
According to this, as described in the first embodiment (or 2), the intermediate transmission member can be formed by inexpensive injection molding or the like, regardless of the processing method that requires high costs such as cutting. This can contribute to a reduction in the manufacturing cost of a drive transmission device such as the body drive transmission device 70.

(Aspect R)
In any one of (Aspect A) to (Aspect Q), the root diameter of the inner teeth formed in the intermediate internal teeth such as the internal gear portion 84 is the internal teeth of the intermediate internal teeth. The intermediate transmission member 85 or the like is sufficiently smaller than the inner diameter of the cylindrical portion of the intermediate transmission member.
According to this, as explained in the first embodiment (or 2), it is possible to provide a relief step when using a mold, and to obtain an intermediate transmission member with high processing accuracy. .

(Aspect S)
In any one of (Aspect A) to (Aspect R), the intermediate transmission member such as the intermediate transmission member 85 is in a state in which the rotating body such as the photosensitive drum 1 is mounted on the transmission shaft such as the drum shaft 50. A meshing portion in which the shaft external tooth member such as the external gear 83 and the intermediate internal gear portion such as the internal gear portion 84 mesh with each other, the rotating internal tooth portion such as the rotating internal tooth portion 87 and the external gear portion 86 and the like. The intermediate external tooth portion is provided so as to have a gap in the direction of the rotation center line of the rotating body sufficient to maintain the meshing portion that meshes with the intermediate external tooth portion.
According to this, as described in the first embodiment (or 2), the following effects can be obtained.
It is possible to widen the range in which the intermediate transmission member can swing while maintaining the engagement at the meshing portion where the shaft outer tooth member and the intermediate inner tooth portion mesh with each other and the meshing portion where the rotating body tooth portion and the intermediate outer tooth portion mesh with each other. Out. Therefore, it is possible to perform high-precision rotation with a wider range of absorption such as an axis deviation and further reduced rotation transmission error.

(Aspect T)
In an image forming apparatus such as a copying machine 500 that includes one or more drive transmission devices that transmit a rotational driving force to a rotating body such as the photosensitive drum 1, at least one of the one or more drive transmission devices. As the drive transmission device, a drive transmission device such as the photosensitive member drive transmission device 70 of any one of (Aspect A) to (Aspect S) is provided.
According to this, as described in the first embodiment (or 2), there is provided an image forming apparatus capable of producing the same effect as any one of the drive transmission devices of (Aspect A) to (Aspect S). it can.

(Aspect U)
In (Aspect T), the rotating body includes a developing roller, a developing screw, a photosensitive drum such as the photosensitive drum 1, a secondary transfer roller such as the secondary transfer roller 7, and an intermediate transfer belt such as the stretching roller 12. It is at least one of driving rollers to be driven.
According to this, as described in the first embodiment (or 2), it is possible to reduce the rotation transmission error when transmitting the rotational driving force to the rotating body related to the image forming process, and high-quality image formation is possible. It becomes.

DESCRIPTION OF SYMBOLS 1 Photosensitive drum 2 Charging device 3 Static elimination lamp 4 Cleaning apparatus 5 Intermediate transfer belt 6 Primary transfer roller 7 Secondary transfer roller 8 Fixing roller pair 9 Developing device 9 Developing device 10 Photoconductor driving device 11, 12, 13 Stretching roller 14 Tension roller 15 Transfer paper transport belt 16 Stretch roller pair (transfer paper transport belt)
DESCRIPTION OF SYMBOLS 17 Optical writing device 18 Fixing device 19 Belt cleaning device 20 Drive motor 21 Motor output shaft 22 Internal tooth fixed flange 30 Planetary gear reduction device 31 First sun gear 32 Internal gear 33 First planetary gear 34 First carrier 35 First Carrier pin 36 Second sun gear 37 Second planetary gear 38 Second carrier 39 Second carrier pin 40 Output shaft (planetary gear reduction device)
41 Joint 41a Slit 42 Internal gear cap 43 Screw 44 Speed detection means 50 Drum shaft 51a, b, c, d Bearing 52 Drum cylinder 53a Rear side flange member 53b Front side flange member 54 Photosensitive drum unit frame 56 Drum unit positioning member 59 Coaxial Restricting member 61 Front side body frame 61a Mounting face plate 62 Rear side body frame 63 Drive frame 64 Stud 67 Output gear 68 Motor gear 70 Photoconductor drive transmission device 71 Upstream retaining member 72 Upstream retaining member 73 Downstream retaining member 74 Downstream stop member 80 Drive connecting portion 83 External gear 84 Internal gear portion 85 Intermediate transmission member 86 External gear portion 87 Rotating body tooth portion 89 Downstream side stop portion 90 Mold 91 Upper die 92 Lower die 93 Channel 94 Pin gate 95 Cavity 96a, 96b Parting line 97 Communication hole 98 Compressed gas supply source 99 Die dividing line 100 Copier main body 101 Paper feed path 102 Registration roller 103 Manual paper feed path 104 Paper feed roller (manual feed)
105 Manual feed tray 106 Paper discharge roller pair 107 Paper output tray 108 Separation roller (manual feed)
200 paper feed table 201 paper feed cassette 202 paper feed roller 203 separation roller 204 paper feed path 205 transport roller 300 scanner 301 contact glass 302 first travel body 303 second travel body 304 imaging lens 305 reading sensor 400 automatic document feeder 401 Platen 500 Copier L Light beam

JP 2011-197298 A

Claims (13)

In the drive transmission device having an intermediate transmission member in the drive transmission path between the drive source and the rotating body,
A transmission shaft that transmits a rotational driving force to the rotating body, and a shaft outer tooth member that is fixed to the transmission shaft;
The intermediate transmission member has an intermediate internal tooth part formed with internal teeth and an intermediate external tooth part formed with external teeth, both of which have the same tooth center in the same straight line,
The intermediate internal tooth portion meshes with the outer shaft tooth member, and the intermediate external tooth portion meshes with a rotating internal tooth portion of an internal tooth provided on the rotating body,
In the rotation center line direction of the rotating body, at least one of the intermediate internal tooth portion and the intermediate external tooth portion is provided on the inner side of the rotating body than the end portion on the drive source side of the outer periphery of the rotating body. Drive transmission device. The drive transmission device according to claim 1,
The drive transmission device, wherein the intermediate internal tooth portion is provided inside the rotary body in the direction of the rotation center line of the rotary body than the intermediate external tooth portion. The drive transmission device according to claim 2, wherein
The drive source side end of the tooth in the rotating body is inside the rotating body or on the drive source side of the outer periphery of the rotating body in the direction of the rotation center line of the rotating body. Provided at the same position as the end,
The drive transmission device according to claim 1, wherein the intermediate transmission member has a reference circle diameter of external teeth of the intermediate external tooth portion larger than a reference circular diameter of internal teeth of the intermediate internal tooth portion. In the drive transmission device according to any one of claims 1 to 3,
A coaxial regulating member that regulates the coaxiality between the rotating body and the transmission shaft is provided on the rotating body,
The transmission shaft passes through the rotating body;
The drive transmission device, wherein the rotating body is detachably attached to the transmission shaft. The drive transmission device according to claim 4, wherein
The rotating body includes an end fixing member that is fixed to a driving source side end portion and has the rotating body tooth portion. The drive transmission device according to claim 5, wherein
In a state where the rotating body is not attached to the transmission shaft, the intermediate transmission member is held on the rotating body side. The drive transmission device according to claim 6, wherein
The end fixing member has a downstream retaining portion on the downstream side of the tooth part in the rotating body that prevents the intermediate transmission member from falling off in the downstream direction in the mounting direction of the rotating body with respect to the transmission shaft. A drive transmission device characterized by that. The drive transmission device according to claim 7, wherein
The coaxial transmission member is provided in the rotating body as a separate member from the end fixing member. The drive transmission device according to claim 5, wherein
In the state where the rotating body is not mounted on the transmission shaft, the intermediate transmission member is held on the transmission shaft side. The drive transmission device according to claim 9, wherein
An upstream retaining member for preventing the intermediate transmission member from falling off and a downstream retaining member on the upstream side and the downstream side of the shaft external tooth member in the mounting direction of the rotating body with respect to the transmission shaft; A drive transmission device characterized by the above. The drive transmission device according to claim 10, wherein
The intermediate transmission member has two cylindrical parts with different outer diameters, and the inner teeth of the intermediate inner tooth part are formed on the inner periphery of the small-diameter cylindrical part on the smaller outer diameter side, and the outer diameter is larger. The external teeth of the intermediate external tooth portion are formed on the outer periphery of the large diameter cylindrical portion,
The upstream retaining member has an outer peripheral diameter larger than a tip circle diameter of an inner tooth of the intermediate inner tooth portion,
The downstream transmission retaining member has an outer diameter smaller than an inner diameter of the small-diameter cylindrical portion and larger than a tip diameter of an inner tooth of an intermediate inner tooth portion. The drive transmission device according to any one of claims 9 to 11,
The drive transmission device, wherein the end fixing member is integrally provided with the coaxial restriction member. In an image forming apparatus including one or more drive transmission devices that transmit a rotational driving force to a rotating body,
An image forming apparatus comprising the drive transmission device according to claim 1 as at least one of the one or more drive transmission devices.