JP2013213549A - Driving force transmission device, driving device and imaging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a driving force transmission device which is equipped with a joint having an intermediate transmission member, and is capable of absorbing eccentricity, declination and axial displacement of rotary shafts between the driving side and the driven side, and reducing vibration due to looseness in fitting parts without degrading rotational rigidity.SOLUTION: A drive transmission device 115 includes a detachable coupling 130 including: a driving-side member 131 connected to an output shaft 123 of a drive motor 121; a driven-side member 132 connected to a drum driving shaft 91 of a photoreceptor drum 40; and an intermediate body 140 for transmitting rotational driving force between the driving-side member 131 and the driven-side member 132. The drive transmission device 115 has a brake mechanism 150 which presses a brake pad 152 provided at the front end of a brake arm 151 against the outer peripheral surface of a brake disc 142 provided around the intermediate body 140 of the coupling 130 so as to apply friction force therebetween.

Description

  The present invention relates to a driving force transmission device used in an image forming apparatus such as a facsimile, a printer, and a copying machine, a driving device including the driving force transmission device, and an image forming apparatus.

  Conventionally, a rotating body such as a latent image carrier that is rotated by a rotational driving force transmitted from a driving source or a developing body such as a developing roller that is a developer carrier is directly or in units of an apparatus main body or an operating position. There is known an image forming apparatus including a drive device that is detachably or movably provided with respect to the image forming apparatus. Such a driving device of an image forming apparatus includes a portion of a driving device on the side provided with a driving source that does not move when the rotated body or unit is removed or moved (hereinafter referred to as the driving side), and the rotated body or unit. In many cases, a portion that moves together (referred to as a driven side) is connected and released (separated) by a driving force transmission device such as a joint (hereinafter referred to as a coupling) that can be contacted and separated.

  As for the configuration of the coupling, an Oldham coupling, a spline type coupling, and the like are conventionally known. In any coupling, there is a case where a predetermined gap is provided between the key and the key groove to be fitted depending on the application, or a backlash (play) such as a predetermined back crush is provided on the tooth shape engaged with each other. By providing backlash in this way, even if there is a slight eccentricity, declination, or misalignment between the output shaft on the driving side and the input shaft on the driven side, This is because the rotational driving force can be transmitted by absorbing the shaft misalignment.

  For example, Patent Document 1 describes a configuration of a driving force transmission device provided with an Oldham coupling as follows. Even if the output shaft on the drive side or the input shaft on the driven side has eccentricity, declination, or shaft misalignment that cannot be absorbed by the gap between the key and key groove, the eccentricity, declination, shaft The driven side coupling is provided with a certain degree of freedom so as to absorb the deviation and transmit the smooth rotational driving force. Then, when the unit (developer) is moved so as to be disconnected from the driving side, the posture of the coupling on the driven side is regulated by providing an elastic member, and the coupling of the driven side at the time of releasing the coupling is restricted. This is to reduce the noise caused by it or to suppress poor connection (engagement failure) at the time of connection.

  Patent Document 2 describes the configuration of a driving force transmission device provided with a spline type coupling having the following intermediate transmission member (hereinafter referred to as an intermediate body). In this configuration, an impact absorbing mechanism made of an elastic member is provided in series between the output shaft and the coupling, or between the coupling and the input shaft. By using a coupling with an intermediate body, even if there is eccentricity, declination, or misalignment between the output shaft and input shaft, the eccentricity, declination, or misalignment is absorbed. The rotational driving force can be transmitted. Then, by providing an impact absorbing mechanism, impact vibration caused by back crushes provided on the respective tooth forms constituting the fitting portion between the spline on the driving side and driven side of the coupling and the intermediate body (hereinafter referred to as vibration) The transmission to the drive side (output shaft side) or the driven side (input shaft side) can be reduced.

  However, in the configuration described in Patent Document 1, since a predetermined gap is provided in the key and the key groove to be fitted, due to fluctuations in the rotational speed of the drive source and fluctuations in the rotational load of the rotated body, the key In the key groove fitting portion, there is a backlash in the rotational direction. Then, due to the play, the key and the key groove are contacted and separated repeatedly, and vibration is generated in the coupling, and this vibration is transmitted to the driving side and the driven side. When the vibration generated by the coupling is transmitted in this way, there is a high possibility that the rotation of the rotated body with high accuracy cannot be performed.

  On the other hand, in the configuration described in Patent Document 2, by providing the shock absorbing mechanism as described above, it is possible to reduce the transmission of the vibration generated in the fitting portion due to the back crash to the driving side or the driven side. However, the following problems may occur. In the first place, it is not a configuration that suppresses the occurrence of coupling vibration caused by the back crushing, so contact and separation are repeated at the meshing part that is the fitting part between the intermediate body and the driving side member and driven side member of the coupling. Vibration will occur. As a result, there is a high possibility that the vibration generated at the tooth meshing period or double period generated by providing the intermediate body cannot be sufficiently suppressed. Further, since an elastic member (silicone rubber) is provided in series between the coupling and the output shaft or input shaft as an impact absorbing mechanism, the rotational rigidity of the driving force transmission device is surely lower than the meshing rigidity of the coupling. It depends on the rigidity of the elastic member that can be considered. Since the rigidity of the elastic member is determined in this way, the rotational phase of the driven side relative to the driving side may be delayed, or an accurate equiangular speed operation may not be performed. There is a high possibility that it cannot be rotated.

The present invention has been made in view of the above problems, and an object thereof is to provide the following driving force transmission device.
It has a joint with an intermediate transmission member and absorbs eccentricity, declination, and axial misalignment of the rotating shaft between the driving side and the driven side, and is caused by play of the fitting portion without reducing rotational rigidity. This is a driving force transmission device capable of suppressing vibration.

In order to achieve the above object, the invention according to claim 1 is a drive-side member that is coaxially connected to a drive-side output shaft, and a driven-side member that is coaxially connected to a driven-side input shaft. A joint having an intermediate transmission member fitted to each of the driving side member and the driven side member in a substantially coaxial manner with a predetermined play, and the rotational driving force of the output shaft is input through the joint. The drive transmission device for transmitting to the shaft is characterized in that a rotational load applying mechanism is provided for applying a rotational load in at least one direction to the intermediate transmission member when the rotational driving force is transmitted.
According to the present invention, since the intermediate transmission member is fitted to the driving side member and the driven side member with predetermined play respectively, eccentricity, declination, and axial deviation occur between the output shaft and the input shaft. Even in this case, it is possible to transmit the rotational driving force that absorbs the eccentricity, the declination, and the axial deviation at the fitting portions of the driving side member and the driven side member and the intermediate transmission member. That is, it is possible to transmit a rotational driving force that absorbs a larger eccentricity, declination, and axial deviation than a joint that does not have an intermediate transmission body with a similar degree of play.
The rotational load applying mechanism causes a rotational load in one direction to act on the intermediate transmission member when transmitting the rotational driving force, or the intermediate transmission member is relative to at least one of the driving side member and the driven side member. When rotating, a rotational load can be applied to the intermediate transmission member. By causing the rotational load to act as described above, the intermediate transmission member, the driving side member, and the driven side member are caused by the play set in the fitting portion between the intermediate transmission member, the driving side member, and the driven side member. Occurrence of vibrations caused by repeated contact and separation of the fitting portion with each other can be suppressed.
Further, since the generation of vibration can be suppressed by applying a rotational load to the intermediate transmission member as described above, the rotational rigidity of the driving force transmission device is not reduced unlike the configuration of Patent Document 2.

The present invention can transmit rotational driving force that absorbs eccentricity, declination, and axial deviation. And generation | occurrence | production of the vibration which a fitting part repeats a contact and separation | spacing can be suppressed. Further, the rigidity of the fitting portion between the intermediate transmission member, the driving side member, and the driven side member is not reduced.
Therefore, it has a joint with an intermediate transmission member, absorbs eccentricity, declination, and misalignment of the rotating shafts on the driving side and driven side, and frees the mating portion without reducing rotational rigidity. It is possible to provide a driving force transmission device that can suppress the vibration caused.

1 is an explanatory diagram of an overall configuration of an image forming apparatus according to an embodiment. 1 is an explanatory diagram of a drum drive device according to Embodiment 1. FIG. Explanatory drawing of the rotational load provision mechanism provided in the coupling which concerns on Example 1. FIG. Explanatory drawing of the transmission model of the rotational driving force by the coupling which concerns on Example 1. FIG. FIG. 6 is an explanatory diagram of a drum driving device according to a second embodiment. FIG. 6 is an explanatory diagram of a drum driving device according to a third embodiment. FIG. 6 is an explanatory diagram of a drum driving device according to a fourth embodiment. FIG. 9 is an explanatory diagram of a drum driving device according to a fifth embodiment.

  A plurality of embodiments in which the present invention is applied to a rotation driving device for a photosensitive drum that is a latent image carrier of a color-compatible MFP (hereinafter, referred to as a multi-function device 500) that is an electrophotographic image forming apparatus. Examples will be described with reference to the drawings. FIG. 1 is an explanatory diagram of the overall configuration of the image forming apparatus according to the present embodiment.

  First, the configuration and operation of the multi-function device 500 of the present embodiment common to each example will be described. As shown in FIG. 1, the multi-function device 500 is mainly composed of the following. An image forming unit 100 that forms an image, a paper feed table 200 on which the image forming unit 100 is placed, a scanner 300 mounted on the image forming unit 100, and a document mounted on the scanner 300 This is an automatic transfer device (ADF) 400.

  The scanner 300 is placed on the contact glass 301 as the first traveling body 303 mounted with a light source for document illumination, a mirror, and the like and the second traveling body 304 mounted with a plurality of reflecting mirrors reciprocate. The scanned original is read and scanned. The scanning light sent out from the second traveling body 304 is condensed on the imaging surface of the reading sensor 306 installed behind the imaging lens 305, and then read as an image signal by the reading sensor 306.

  The image forming unit 100 is provided with photosensitive drums 40Y, 40M, 40C, and 40Bk corresponding to toners of yellow (Y), magenta (M), cyan (C), and black (Bk) as latent image carriers. It has been. Around the respective photosensitive drums 40, various units for performing an electrophotographic process such as a developing device 70, a charging device 85, and a photosensitive member cleaning device 86 are arranged, whereby an image forming unit 38 (Y, M, C, Bk) is arranged. ) Is formed. Each image forming unit 38 can be attached to and detached from the printer main body, so that consumable parts can be replaced at a time. Four image forming units 38 are provided in parallel to form the tandem image forming unit 20. Here, the configuration of each image forming unit 38 is different only in the color of the toner to be used, and the configuration and operation thereof are the same. Therefore, in the following description, symbols Y, M, C, and Bk are omitted as appropriate. I will explain.

  Each image forming unit 38 includes a photosensitive drum unit 90 (not shown). As will be described in detail later, a drum drive shaft 91 (not shown), which is an input shaft for the rotational driving force of the photosensitive drum 40 held by the drum holder 92 (not shown) of the photosensitive drum unit 90, is provided on one side of the drum holder 92. It is provided so that the front-end | tip may come out from the shaft hole provided in. A driven side member of a spline-type joint provided in a drive transmission device of a drum drive device 110 (not shown) is connected to the tip of the drum drive shaft 91, and an output shaft of a drive source when the photosensitive drum unit 90 is mounted. Connected to.

  In the developing device 70 of each image forming unit 38, the developer containing the four color toners is used. In the developing device 70, a developing roller 71 that is a developer carrying member carries and conveys the developer, and develops a latent image on the photoconductive drum 40 at a position facing the photoconductive drum 40.

  Above the tandem-type image forming unit 20, an exposure device 31 is provided that forms a latent image by exposing the photosensitive drum 40 with laser light or LED light based on image information.

  In addition, an intermediate transfer belt 15 that is an intermediate transfer member made of an endless belt member is disposed at a lower position facing the photosensitive drum 40 of the tandem type image forming unit 20. The intermediate transfer belt 15 is supported by a support roller 34, a support roller 35, and a secondary transfer backup roller 36. A primary transfer device 62 that transfers the toner images of the respective colors formed on the photosensitive drum 40 to the intermediate transfer belt 15 is disposed at a position adjacent to the photosensitive drum 40 via the intermediate transfer belt 15. .

  Below the intermediate transfer belt 15, a secondary transfer device 19 that collectively transfers a toner image formed on the surface of the intermediate transfer belt 15 to the sheet P conveyed from the paper feed cassette 44 of the paper feed table 200. Is arranged. The secondary transfer device 19 includes a secondary transfer roller 23 and a contact / separation mechanism (not shown) that supports the secondary transfer roller 23 so as to be able to contact and separate from the intermediate transfer belt 15. The secondary transfer device 19 presses the secondary transfer roller 23 against the secondary transfer backup roller 36 via the intermediate transfer belt 15 to transfer the toner image on the intermediate transfer belt 15 onto the sheet P.

  A belt cleaning unit 37 is provided to remove toner remaining on the surface of the intermediate transfer belt 15. The belt cleaning unit 37 causes a cleaning blade made of, for example, a fur brush or urethane rubber to contact the intermediate transfer belt 15 and scrapes off secondary transfer residual toner adhering to the intermediate transfer belt 15.

  A fixing device 60 is provided adjacent to the secondary transfer device 19, and the fixing device 60 fixes an image on the sheet P. The fixing device 60 mainly includes a heating roller 66 in which a heater as a heat source is incorporated, and a pressure roller 67 pressed against the heating roller 66.

  A reversing device 28 for reversing the sheet P is disposed below the secondary transfer device 19 and the fixing device 60. The reversing device 28 reverses the sheet P so as to record images on both sides of the sheet P.

  Next, the operation of the multi-function device 500 configured as described above as a copier will be described. The original document is set on the document table 30 of the automatic document feeder 400 shown in FIG. 1, or the automatic document feeder 400 is opened to set the document on the contact glass 301 of the scanner 300, and the automatic document feeder 400 is closed. . When a start switch (not shown) on the operation panel is pressed in this state, when the document is set on the automatic document feeder 400, the document is transported and moved onto the contact glass 301, and then the first traveling body. 303 and the second traveling body 304 are caused to travel. When the document is set on the contact glass 301, the scanner 300 is immediately driven to cause the first traveling body 303 and the second traveling body 304 to travel. The first traveling body 303 irradiates light from the light source and receives reflected light from the document surface. The reflected light is reflected toward the second traveling body 304, the reflected light is further reflected by the mirror of the second traveling body 304, is incident on the reading sensor 306 through the imaging lens 305, and the document content is read by the reading sensor 306. .

  Further, by pressing a start switch on the operation panel, a drive motor (not shown) is driven to rotate and drive the support roller 34 which is also a drive roller, and the other support roller 35 and the secondary transfer backup roller 36 are moved. Rotate following. By rotating in this way, the intermediate transfer belt 15 is rotated. At the same time, the photosensitive drum 40 is uniformly charged by the charging device 85 in each image forming unit 38. Then, an electrostatic latent image is formed on each charged photosensitive drum 40 by irradiating writing light from a laser, an LED, or the like from the exposure device 31 according to the content read by the scanner 300. Toner is supplied from the developing device 70 to the photosensitive drum 40 on which the electrostatic latent image is formed, and the electrostatic latent image is visualized. On each photosensitive drum 40, yellow (Y), magenta (M), A single color image of cyan (C) and black (Bk) is formed. A single color image is sequentially primary transferred by the primary transfer device 62 so as to overlap the intermediate transfer belt 15, and a composite color image is formed on the intermediate transfer belt 15. Residual toner is removed from the surface of the photosensitive drum 40 after the image transfer by the photosensitive member cleaning device 86, and the static electricity is removed by a static eliminator (not shown) to prepare for image formation again.

  By pressing the start switch on the operation panel, one of the paper feed rollers 42 of the paper feed table 200 is selected and rotated, and the sheet P is loaded from one of the paper feed cassettes 44 provided in the paper bank 43 in multiple stages. Pull out. The fed sheets P are separated one by one by the separation roller 45 and inserted into the paper feed path 46, transported by the transport roller pair 47 and guided to the paper feed path 48 in the image forming unit 100, and to the registration roller pair 49. Stop it by hitting it. Next, the registration roller pair 49 is rotated in synchronization with the composite color image on the intermediate transfer belt 15, and the sheet P is fed between the intermediate transfer belt 15 and the secondary transfer device 19 and transferred by the secondary transfer device 19. Then, the color image is transferred onto the sheet P.

  The sheet P carrying the unfixed toner image that has passed through the secondary transfer roller 23 is conveyed to the fixing device 60, and heat and pressure are applied by the fixing device 60 to fix the transferred image. The sheet P after image fixing is switched by the switching claw 55 and discharged by the discharge roller pair 56 and stacked on the paper discharge tray 57 or switched by the switching claw 55 and introduced into the reversing device 28. The sheet P introduced into the reversing device 28 is reversed and guided to the transfer position again, and an image is recorded on the back surface. Thereafter, the sheet P is discharged onto the discharge tray 57 by the discharge roller pair 56. At this time, residual toner remaining on the intermediate transfer belt 15 after image transfer is removed by the belt cleaning unit 37 to prepare for re-image formation by the tandem type image forming unit 20.

  Next, a coupling which is a spline type joint having an intermediate transmission member (hereinafter referred to as an intermediate body) provided in the drum driving device 110 which is a driving device of the photosensitive drum unit 90, which is a characteristic part of the present embodiment. A drive transmission device equipped with a plurality of embodiments will be described. Here, the configuration of the drum driving device 110 corresponding to each image forming unit 38 differs only in the color of the toner used in each corresponding image forming unit 38, and the configuration and operation are the same. Therefore, in the following description, the symbols Y, M, C, and Bk are omitted as appropriate.

Example 1
A first example of the drum driving device 110 according to the present embodiment will be described with reference to the drawings. FIG. 2 is an explanatory view of the drum driving device 110 according to the present embodiment, and FIG. 3 is an explanatory view of a rotational load applying mechanism provided in the coupling 130 according to the present embodiment, and is a cross-sectional view taken along aa ′ in FIG. Is shown. FIG. 4 is an explanatory diagram of a rotational driving force transmission model by the coupling 130 according to the present embodiment.

  As shown in FIG. 2, the drum driving device 110 of this embodiment mainly includes a drum driving shaft 91 that is an input shaft for the rotational driving force of the photosensitive drum 40, a driving unit 120, and a drum driving shaft 91 and a driving unit 120. The drive transmission device 115 is provided with a coupling 130 that connects an output shaft 123 that is an output shaft of a rotational driving force.

  The drum drive shaft 91 is fixed to a photoreceptor flange provided at both ends of the photoreceptor drum 40, and is rotatably held by a drum holder 92 of the photoreceptor drum unit 90 via a bearing 93. It is also a component. In addition, a driven side member 132 of the coupling 130 is coaxially fixed (connected) to an end portion on the driving side of the drum driving shaft 91 so that the intermediate member 140 of the coupling 130 can be contacted and separated. The photosensitive drum unit 90 is configured to be detachable from the apparatus main body. The drum holder 92 is configured to be attachable to and detachable from the apparatus main body. The drum holder 92 is attached by moving in the right direction in the figure and can be detached by moving in the left direction in the figure.

  The bottom of the drum holder 92 is provided with a lock hole that fits into the lock pin 94 of the lock mechanism provided on the apparatus main body side, and the drum holder 92 is fitted by fitting the lock pin 94 and the lock hole after the mounting. Restrict to the specified position. That is, the photosensitive drum unit 90 is regulated to a predetermined position by fitting the lock pin 94 and the lock hole after the mounting. Further, when the photosensitive drum unit 90 is removed, a release lever (not shown) provided on the apparatus main body side is operated to move the lock pin 94 downward to release the engagement with the lock hole. The drum unit 90 can be removed.

  The drive unit 120 includes a drive motor 121 and an end plate 122, and the end plate 122 is screwed and positioned on a side plate (not shown) of the apparatus main body. A drive side member 131 of the coupling 130 is coaxially fixed (connected) to the driven side end of the output shaft 123 of the drive motor 121.

  The coupling 130 includes a driving side member 131, an intermediate body 140, and a driven side member 132. The driving side member 131 and the driven side member 132 have internal teeth, and the intermediate body 140 has external teeth. It is a spline type joint formed. Then, at the meshing portion that is a fitting portion between the intermediate body 140, the driving side member 131, and the driven side member 132, the rotational driving force is transmitted by meshing each tooth. Further, as described above, the driven member 132 fixed to the drum driving shaft 91 and the intermediate body 140 are separated from each other, whereby the photosensitive drum unit 90 can be attached to and detached from the apparatus main body.

  As described above, in the configuration in which the coupling 130 having the intermediate body 140 is provided in the drive transmission device 115, errors such as eccentricity, declination, and misalignment are caused in the shaft centers of the drum drive shaft 91 and the output shaft 123 to be coupled. Even if this occurs, the error can be absorbed by the meshing portions of the intermediate body 140, the driving side member 131, and the driven side member 132, respectively. That is, it is possible to transmit a rotational driving force that absorbs a larger eccentricity, declination, and shaft misalignment than a joint that does not have an intermediate transmission body with the same degree of play. Absorption of such errors is absorbed by backlash provided at the meshing of teeth in spline coupling.

  However, due to the play (play) caused by this backlash, minute torque fluctuations at the time of rotation of the photosensitive drum 40 or the drive motor 121, which are driven bodies, and a resonance phenomenon in the resonance band of the drum drive device 110 occur. There is a case. For this reason, in the meshing part of the intermediate body 140 and the driving side member 131 and the driven side member 132, each member does not rotate under a load in one direction, but transmits the rotational driving force while repeating contact and separation. become. In the driven side member 132 that is the driven side, the intermediate body 140 meshes with both tooth surfaces of the driving side member 131 and the driven side member 132 in addition to the meshing of the teeth of the coupling 130. As a result, vibration is generated at the tooth meshing period or double period generated by providing the intermediate body 140.

  In order to suppress the above phenomenon, the inventors conducted intensive experiments and applied the rotational load generated by the frictional force to the intermediate body 140 of the coupling 130 to cause the backlash without reducing the rotational rigidity. A drive transmission device 115 capable of suppressing vibrations has been devised. In the drive transmission device 115 provided in the drum drive device 110 of the present embodiment, the following brake mechanism 150 is provided as a rotational load application mechanism that applies a rotational load to the intermediate body 140. As shown in FIG. 2, in order to apply a frictional force to the intermediate body 140, a brake disk 142 for applying a friction brake from the outside is formed in the intermediate body 140 at a position where the tooth profile does not mesh with the intermediate body 140. Concentric with the external teeth. Since the intermediate body 140 of the present embodiment is made of resin, the brake disk 142 can be easily formed by resin molding.

  A brake pad 152, which is a friction member of the brake mechanism 150 that is supported on the outer peripheral surface of the brake disk 142 and is set on the apparatus main body side and capable of setting a pressure applied to the outer peripheral surface of the brake disk 142, can be used to suppress the vibration. Press with a weak force. As shown in FIG. 3, the brake mechanism 150 includes a brake arm 151, a brake pad 152 affixed to a surface facing the brake disk 142 on one end side of the brake arm 151, and the brake arm 151 as an outer peripheral surface of the brake disk 142. And a brake holding mechanism 157 for pressing and holding the brake. The brake arm 151 is made of a rigid material such as metal. As described above, the brake pad 152 is attached to one end side, and the other end is held so as to be pressed against the outer peripheral surface of the brake disc 142 by the brake holding mechanism. .

The cross-sectional shape in the vicinity where the brake arm 151 contacts the outer peripheral surface of the brake disc 142 via the brake pad 152 is formed with a U-shaped detent 156 with the opening facing downward as shown in FIG. The brake pad 152 is sandwiched in the width direction. The detent 156 regulates the movement of the intermediate body 140 in the thrust direction, and thus an excessive load is caused by the end portion of the intermediate body 140 coming into direct contact with the driving side member 131 or the driven side member 132 due to a shifting phenomenon during operation. Torque generation can be prevented. Further, when the photosensitive drum unit 90 is attached to or detached from the apparatus main body, it is possible to provide a function for preventing the intermediate body 140 from falling off due to the action of the thrust force accompanying the attachment and detachment.
Also, as the brake pad 152 that presses against the outer peripheral surface of the brake disk 142 to ensure a frictional force, a polymer synthetic rubber such as NBR rubber, a cork sheet, or the like can be used.

  As shown in FIG. 3, the brake holding mechanism 157 can set a pressing force on the other end of the brake arm 151, and includes a holding member 153, a pressure spring 155, and a pressure spring 155 supported by the apparatus main body. The adjusting screw 154 is configured to adjust the applied pressure. On the substantially horizontal upper surface of the holding member 153, the other end of the brake arm 151 with the brake pad 152 affixed is supported so that it slightly floats, and is added to a hole (not shown) provided in the brake arm 151. The adjustment of the pressure is made possible by screwing in the adjustment screw 154 that pressurizes via the pressure spring 155.

With the configuration described above, the driving side member 131 fixed to the output shaft 123 serving as the rotation input shaft of the coupling 130 and the driven side fixed to the end portion of the drum driving shaft 91 serving as the rotation output shaft. A rotational driving force transmission model as shown in FIG. 4 can be formed between the member 132 and the member 132.
Specifically, a): tooth rigidity at each meshing portion of the coupling portion, a): brake function by the brake mechanism 150 that is a rotational load applying mechanism, c) by the viscosity of the brake pad 152 that is a friction member This is a rotational driving force transmission model having a damper function in parallel. By providing a) to c) in parallel as described above, vibration due to backlash can be suppressed and the rigidity of the teeth at each meshing portion of the coupling portion can be secured to drive the drum on the driven side. The driving torque necessary for rotationally driving the shaft 91 can be transmitted without causing a rotational phase delay.

By not causing the rotational phase delay in this way, even if there is a rotational fluctuation of one rotation fluctuation (up to several tens of hertz) of the output shaft 123, by the variable control of the motor rotation speed of the drive motor 121, An operation of stabilizing the rotational driving of the photosensitive drum 40 as the rotated body is possible.
The damper function of c) can be obtained at the same time depending on the selection of the material of the brake pad 152 on which the brake function of b) is applied. For example, it is effective to select a polymer synthetic rubber such as NBR rubber having a large tan δ value.
The configuration of Patent Document 2 described in the above prior art is a model in which an elastic member is arranged in series with the coupling, and the transmission rigidity is determined by this elastic member. Therefore, the transmission shown in FIG. It was adopted based on a completely different concept from the model.

  As described above, the brake mechanism 150 according to the present embodiment has a simple configuration. A): rigidity of teeth at each meshing portion of the coupling portion, a): brake function by the brake mechanism 150 that is a rotational load applying mechanism, c) ): It is possible to acquire in parallel the damper function due to the viscosity of the brake pad 152 which is a friction member.

  Further, by using the coupling 130 as a joint having the intermediate body 140 as described above, the eccentricity and declination between the output shaft 123 on the driving side and the drum driving shaft 91 which is the input shaft on the driven side can be achieved. Even when an axial deviation occurs, it is possible to transmit a rotational driving force that absorbs eccentricity, declination, and axial deviation. Then, when the meshing portion between the intermediate body 140 and the driving side member 131 or the driven side member 132 is about to be separated by the rotational load applying mechanism, a one-way rotational load due to frictional force is applied to the intermediate body 140. Can do. By causing the rotational load to act in this way, the intermediate body 140, the driving side member 131, and the driven side are caused by the backlash set in the meshing portion between the intermediate body 140 and the driving side member 131 and the driven side member 132. Generation of vibration caused by repeated contact and separation of the meshing portion with the member 132 can be suppressed, and smooth and stable rotational driving force can be transmitted without vibration.

In addition, since the generation of vibration is suppressed by applying a one-way rotational load generated by the brake mechanism 150, the intermediate body 140, the driving side member 131, and the driven side member are different from the configuration of Patent Document 2. The rigidity at the meshing portion with 132 is not reduced.
Further, by selecting a polymer synthetic rubber such as NBR rubber having a large tan δ value as a material of the brake pad 152 used for the brake mechanism 150 which is a rotational load applying mechanism, a viscous damper function for damping vibration by viscosity is provided. In addition, vibration in a high frequency band can be suppressed.

  Therefore, the coupling 130 having the intermediate body 140 is provided, and the eccentricity, declination, and axial deviation of the rotating shaft are absorbed between the driving-side output shaft 123 and the driven-side input shaft drum drive shaft 91. In addition, it is possible to provide a driving force transmission device that can suppress vibration due to play (play) of the meshing portion without reducing rotational rigidity.

Further, by using the coupling 130 as a spline type joint, it is possible to increase the rotational torque that can be transmitted and rotate the photosensitive drum 40 and the intermediate transfer belt 15 that have a relatively large rotational load in the multi-function device 500. The present invention can also be applied to rotational driving of the support roller 34 that is a driving roller to be driven.
Further, a detent 156 is formed on the brake arm 151 of the brake mechanism 150 to restrict the movement of the intermediate body 140 in the thrust direction, so that the photosensitive drum unit 90 can be attached and detached when it is attached to and detached from the apparatus main body. A function of preventing the intermediate body 140 from dropping off due to the action of the accompanying thrust force can be provided. Accordingly, when the photosensitive drum unit 90 is mounted again after being removed, the coupling 130 can be correctly connected, and the transmission function of the rotational driving force of the coupling 130 can be normally functioned. Further, in the present embodiment, the configuration in which the detent 156 is formed on the brake arm 151 of the brake mechanism 150 has been described. However, the configuration may be such that the detent 156 is provided independently and supported by the apparatus main body.

(Example 2)
A second example of the drum driving device 110 according to the present embodiment will be described with reference to the drawings. The present embodiment differs from the first embodiment only in the point relating to the configuration of the rotational load applying mechanism. Therefore, the same configurations / operations, operations / effects, and the like as those of the first embodiment will be omitted as appropriate. Moreover, the same code | symbol is attached | subjected and demonstrated to the same structural member. 5A and 5B are explanatory views of the drum driving device 110 according to the present embodiment, in which FIG. 5A is a cross-sectional explanatory view parallel to the output shaft 123 of the drive motor 121, and FIG. 5B is a cross-sectional view taken along line bb ′ of FIG. It is explanatory drawing of the connection of the compression coil spring 162 and the friction member 163 in FIG.

  In the drum driving device 110 of this embodiment, the following spring-type rotational load applying mechanism 160 is provided as the rotational load applying mechanism provided in the drive transmission device 115. A hollow portion having a circular hollow cross section is formed on the intermediate body 140 so as to be coaxial with the rotation axis, and the spring-type rotational load applying mechanism 160 is projected onto a plane perpendicular to the rotation axis of the intermediate body 140. In this case, it was provided so as to be in the region of the hollow portion formed in the intermediate 140. That is, it was provided so as to be included in the coupling 130. The frictional force that generates the rotational load applied to the intermediate body 140 by the spring-type rotational load applying mechanism 160 causes the friction member 163, which is the friction member included in the spring-type rotational load applying mechanism 160, the drive side member 131, and the target member. The drive-side member 132 is configured to be generated by contact with an inner wall portion (hereinafter referred to as an opposed inner wall portion) facing the axial end portion of the intermediate body 140. The spring-type rotational load applying mechanism 160 includes a compression coil spring 162 that is an elastic member as a pressurizing member that pressurizes the friction member 163 toward the opposing inner wall portions of the driving side member 131 and the driven side member 132. Yes. A rotational load generated by the frictional force generated between the friction member 163 and each opposing inner wall portion by the compression coil spring 162 is applied to the intermediate body 140 via the compression coil spring 162.

  By configuring the drive transmission device 115 in this way, the rotation axis center is centered on the intermediate body 140 that rotates relative to the driving side member 131 and the driven side member 132 by the spring-type rotational load applying mechanism 160. A rotational load can be applied even when rotating in any direction.

Further, the position where the frictional force is applied (generated) can be brought closer to the axial center of the intermediate body 140 as compared with the configuration in which the rotational load applying mechanism is provided outside the intermediate body 140. Furthermore, the pressing force that generates the frictional force is applied in parallel with the axis of the intermediate body 140 so that the intermediate body 140 does not receive the force caused by the pressing force in the direction perpendicular to the axis. it can. Therefore, compared to the configuration in which the rotational load applying mechanism is provided outside the intermediate body 140, the position where the frictional force is applied is brought closer to the axial center of the intermediate body 140, and even when the frictional force fluctuates, In the direction perpendicular to the axial center, and the generation of local force acting on the meshing portion can be reduced to suppress the rotational variation of the intermediate body 140. it can.
In addition, when the spring-type rotational load applying mechanism 160 is projected onto a surface perpendicular to the rotation axis of the intermediate body 140, the spring-type rotational load applying mechanism 160 is provided so as to be within the region of the hollow portion formed in the intermediate body 140. Compared with the configuration in which the rotational load applying mechanism is provided outside 140, the drive transmission device 115 can be reduced in size by the components provided on the apparatus main body side.

  More specifically, the spring-type rotational load applying mechanism 160 of this embodiment includes a compression coil spring 162 disposed inside a hollow intermediate body 140 as shown in FIG. 5A and both ends of the compression coil spring 162. The friction member 163 is fixed to each coil end, and the protrusion 161 is formed on the inner peripheral surface of the intermediate body 140. The intermediate body 140 of the present embodiment is molded with resin, and both end portions of the intermediate body 140 are twisted while twisting the compression coil springs 162 to a plurality of protrusions 161 formed at substantially the center of the inner peripheral surface in the rotation axis direction. The compression coil spring 162 is set so as to protrude evenly. By setting in this way, the compression coil spring 162 is fixed without being disengaged from the inside of the intermediate body 140, and when compressed, the same spring force (repulsive force) is generated symmetrically with respect to the projection 161. To do.

  In addition, friction members 163 are fixed to the linear portions of the coil ends at both ends of the compression coil spring 162, respectively. As shown in FIG. 5B, the friction members 163 are fixed by fitting the linear portions of the coil ends of the compression coil springs 162 into linear grooves provided on the friction members 163 and fixing them. The friction member 163 is made of a material such as urethane rubber or chloroprene rubber, and a necessary friction coefficient can be set by molding the material to an appropriate hardness. A curvature is provided at a portion of the friction member 163 that is in contact with the opposed inner wall portion, and the bias at the contact portion of the pressure applied by the compression coil spring 162 is reduced. By suppressing the bias in this way, it is possible to suppress the occurrence of irregular torque fluctuations when the teeth of the coupling 130, which is a spline-type joint, are engaged. The friction member 163 is fixed to the compression coil spring 162 at both ends of the compression coil spring 162.

  Further, a drop-off prevention ring 143 for preventing the intermediate body 140 from dropping off from the drive side member 131 side is provided on the outer peripheral surface of the center of the intermediate body 140 in the axial center direction. In 156, the movement of the intermediate body 140 in the thrust direction is restricted. By restricting the movement in this way, it is possible to acquire the function of preventing the intermediate body 140 from dropping out as in the first embodiment. In addition, when the photosensitive drum unit 90 is mounted again after being removed, the coupling 130 can be correctly connected, and the transmission function of the rotational driving force of the coupling 130 can be normally functioned.

  When the driven side member 132 is connected to the driving side member 131 holding the intermediate body 140 as described above as the photosensitive drum unit 90 is attached to the apparatus main body, the following is a spring type in the coupling 130 as follows. The rotational load application mechanism 160 operates. The intermediate body 140 of the spline type coupling 130 and the teeth of the driving side member 131 and the driven side member 132 are engaged with each other. At the same time as the meshing, the friction member 163 of the spring-type rotational load applying mechanism 160 is pressed and brought into contact with the opposed inner walls of the driving side member 131 and the driven side member 132 by the pressing force of the compression coil spring 162.

  By applying pressure as described above, each tooth is in contact with and separated from the driving side member 131 and the driven side member 132 so that the teeth come into contact with and separate from each other at the meshing portion of the driving side member 131 and the driven side member 132 and the intermediate body 140. Thus, a rotational load can be applied by applying a frictional force in a direction to suppress the rotation of the intermediate body 140 that is about to rotate. Due to this rotational load, the intermediate body 140 is held without rattling in the rotational direction, and it is possible to continue the transmission of the rotational driving force without vibration during the rotation.

  In addition, the frictional force that generates the rotational load applied to the intermediate body 140 as described above is preferably applied in the vicinity of the rotational axis of the intermediate body 140. That is, in the configuration in which the friction force is applied to the outside of the intermediate body 140, that is, at a position away from the shaft center in the circumferential direction, if the friction force fluctuates, the moment acting in the direction perpendicular to the shaft center is also caused by the friction force. A large fluctuation occurs, and a local force acts on the meshing portion (gear surface) due to this moment variation, and the force acting on the meshing portion increases or decreases to increase the rotational variation. Therefore, the moment caused by the fluctuation of the frictional force is caused by applying a pressing force parallel to the axial center to both ends of the intermediate body 140 or the vicinity of the axial center of one end to cause a frictional force in the vicinity of the axial center. It was decided to suppress the meshing fluctuation by reducing the fluctuation of the mesh.

  In the spring-type rotational load applying mechanism 160 according to the present embodiment, the pressing force parallel to the axis of the intermediate body 140 by the compression coil spring 162 is applied to the vicinity of the end of the rotation axis of the rotating intermediate body 140 as described above. A frictional force is applied to the intermediate 140 by acting on the friction member 163 disposed. By applying the frictional force in this way, the pressing force that generates the frictional force acts in parallel with the axis of the intermediate body 140, and the intermediate body 140 is caused by the pressing force in the direction perpendicular to the axis. You can avoid receiving the power. Therefore, it is possible to suppress the force exceeding the transmission of the rotational driving force by the coupling 130 from acting on the meshing portion.

  Further, the application of the frictional force to the intermediate body 140 by the spring-type rotational load applying mechanism 160 is based on a combination of the elastic force of the compression coil spring 162 that is an elastic member and the friction member 163 disposed near the end of the intermediate body 140. Has been done. Therefore, a frictional force can be obtained and applied to the intermediate body 140 by a composite configuration by contact between the opposing inner wall portion different from the fitting portion of the driving side member 131 and the driven side member 132 and the friction member 163, and driving. This can contribute to downsizing of the transmission device 115.

(Example 3)
A third example of the drum driving device 110 of the present embodiment will be described with reference to the drawings. In the present embodiment and the second embodiment, only the point relating to the configuration in which the friction member 163 is pressed against the opposed inner wall portions of the driving-side member 131 and the driven-side member 132 of the coupling 130 by the rotational load applying mechanism provided in the intermediate body 140. Is different. Therefore, the same configurations / operations, operations / effects, and the like as those of the second embodiment will be omitted as appropriate. Moreover, the same code | symbol is attached | subjected and demonstrated to the same structural member. FIG. 6 is an explanatory diagram of the drum driving device 110 according to the present embodiment.

  In the second embodiment described above, the spring-type rotational load applying mechanism 160 using the compression coil spring 162 that is an elastic member as a pressurizing member that pressurizes the friction member 163 against the opposing inner wall portions of the driving side member 131 and the driven side member 132. explained. On the other hand, the rotational load application mechanism of the present embodiment is a rubber-type rotational load application mechanism 166 provided in a hollow interior in which a low-hardness rubber 164 as an elastic member is formed in the intermediate body 140 as a pressure member.

  As shown in FIG. 6, a substantially cylindrical low-hardness rubber 164 that is long and longer than the length in the axial direction of the intermediate body 140 is disposed in the hollow inside of the intermediate body 140, so that the intermediate body 140 has a substantially center in the axial direction. Bonded to the inner peripheral surface of And it is comprised so that the protrusion amount from the intermediate body 140 of the both ends of the low hardness rubber | gum 164 after adhesion | attachment may become substantially equal. Further, a friction member 163 is provided on the surface of the low hardness rubber 164 facing the opposing inner wall portions of the driving side member 131 and the driven side member 132.

  Further, when the intermediate body 140 provided with the low-hardness rubber 166 is set on the coupling 130, the length of the low-hardness rubber 166 is shortened so that the low-hardness rubber 166 is elastically deformed and shortened in the axial direction of the intermediate body 140. Is set. By setting in this way, when the intermediate body 140 provided with the low hardness rubber 166 is set on the coupling 130, the elastic force corresponding to the elastic deformation of the low hardness rubber 166 is applied to the friction member 163 as a pressing force. Can do. Then, the friction member 163 is pressed toward the opposed inner wall portions of the driving side member 131 and the driven side member 132 to apply a frictional force, and tries to rotate relative to the driving side member 131 and the driven side member 132. A rotational load can be applied to the intermediate 140.

  By configuring the rubber-type rotational load applying mechanism 166 in this way, the friction member 163 is pressurized toward the opposed inner wall portions of the driving side member 131 and the driven side member 132 to apply a frictional force to the intermediate body 140. Can do. Therefore, the same effect as the spring-type rotational load applying mechanism 160 of the second embodiment described above can be obtained.

In the description of the rubber-type rotational load applying mechanism 166 of the present embodiment, an example in which the low-hardness rubber 166 that is an elastic member is used as the pressure member has been described. However, the present invention is limited to such a configuration. Instead, for example, foamable rubber or the like may be used.
In addition, the configuration in which the pressure member made of the low-hardness rubber 166 and the friction member 163 are separately provided and bonded has been described. However, the present invention is not limited to such a configuration. A low-hardness polymer synthetic rubber or the like integrally formed with the friction member may be used. Thus, when forming integrally, a desired friction coefficient is ensured by the kind of material to be used.

Example 4
A fourth example of the drum driving device 110 according to the present embodiment will be described with reference to the drawings. In the present embodiment and Embodiments 2 and 3, the friction member 163 is pressed against the opposed inner wall portions of the driving side member 131 and the driven side member 132 of the coupling 130 by the rotational load applying mechanism provided in the intermediate body 140. Only the point is different. Therefore, the same configuration / operation, operation / effect, and the like as those in the second and third embodiments will be omitted as appropriate. Moreover, the same code | symbol is attached | subjected and demonstrated to the same structural member. FIG. 7 is an explanatory diagram of the drum driving device 110 according to the present embodiment.

  In the second embodiment, the spring-type rotational load applying mechanism 160 using the compression coil spring 162 that is an elastic member as the pressure member, and in the third embodiment, the rubber using the low-hardness rubber 164 that is the elastic member as the pressure member. The rotary load applying mechanism 166 has been described. On the other hand, the rotational load applying mechanism of the present embodiment is configured such that the pair of the first magnetic body 172 and the second magnetic body 173 made of permanent magnets as the pressure member is opposed to the opposing inner wall portion of the driving side member 131 and the driven side member 132. The first magnetic body 172 and the intermediate body 140 are magnetic force type rotational load applying mechanisms 170 provided with second magnetic bodies 173 at both ends of the hollow interior.

  As shown in FIG. 7, the second magnetic body 173 is bonded to both ends of the intermediate body 140 in the axial direction in the axial direction so as to have the south pole on the left side and the north pole on the right side. In addition, the first magnetic body 172 is bonded to the inner walls of the driving side member 131 and the driven side member 132 so as to be the south pole on the left side and the north pole on the right side in the drawing. And the friction sheet 171 which is a friction member is adhere | attached on the surface facing each opposing inner wall part of the magnetic body 173 provided in the intermediate body 140. FIG.

  By constructing the magnetic rotational load applying mechanism 170 in this way, the friction sheet 171 is sandwiched between the pair of the first magnetic body 172 and the second magnetic body 173 that are attracted and attracted to each other by the magnetic force, and the attracting force due to the magnetic force is applied. Use as pressure to ensure friction. Therefore, the same effects as those of the spring-type rotational load applying mechanism 160 of the second embodiment and the rubber-type rotational load applying mechanism 166 of the third embodiment can be obtained.

(Example 5)
A fifth example of the drum driving device 110 of the present embodiment will be described with reference to the drawings. This embodiment differs from Embodiments 1 to 4 only in the point relating to the configuration of the rotational load applying mechanism. Therefore, the same configurations / operations, operations / effects, and the like as those of the first to fourth embodiments will be omitted as appropriate. Moreover, the same code | symbol is attached | subjected and demonstrated to the same structural member. FIG. 8 is an explanatory diagram of the drum driving device 110 according to the present embodiment.

  In the drum driving device 110 of the present embodiment, the following shaft peripheral surface rotational load applying mechanism 180 is provided as a rotational load applying mechanism provided in the drive transmission device 115. As shown in FIG. 8, the axial circumferential surface type rotational load applying mechanism 180 is mainly composed of a donut-like elastic member 181 that is an elastic member that is fixed to the approximate center in the axial direction inside the hollow formed in the intermediate body 140. It is comprised from the cylindrical shaft 182 provided coaxially with the rotating shaft of the drive side member 131 inserted in the hole of the cylindrical elastic member 181.

  Further, in order to restrict the movement of the intermediate body 140 in the thrust direction (to prevent the intermediate body 140 from being removed), a stopper 184 is provided that is connected to the tip of the shaft 182 that penetrates the hole of the donut-like elastic member 181. Teflon (registered trademark) that reduces the frictional force is provided between the stopper 184 and the side surface of the donut-like elastic member 181 so that the frictional force is not generated due to the contact between the side surfaces of the stopper 184 and the donut-like elastic member 181. ) A spacer 183 made of a sheet is interposed. The stopper 184 is provided with a male screw, and the tip of the shaft 182 is provided with a female screw. After inserting the shaft 182 into the hole of the donut-like elastic member 181 and penetrating the tip, the stopper 184 is provided. A male screw provided at 184 is screwed in and fixed.

As described above, the donut-like elastic member 181 is provided with a hole having a predetermined diameter coaxial with the axis of the intermediate body 140. Moreover, the fixing method of the donut-like elastic member 181 to the inner peripheral surface of the hollow body formed in the intermediate body 140 in the center in the axial direction may be either shrink fit by molding or adhesion.
Further, the drive-side member 131 is inserted into the hole of the donut-like elastic member 181 fixed as described above and penetrates from the opposing inner wall portion of the drive-side member 131 to a cylindrical shaft coaxial with the rotation axis. 182 is provided. The shaft 182 is set with a slight plus tolerance with respect to the hole diameter of the donut-like elastic member 181, and is configured such that the hole of the donut-like elastic member 181 is widened by being inserted into the hole of the donut-like elastic member 181. Yes.

When the hole of the donut-like elastic member 181 is widened, the hole of the donut-like elastic member 181 and the surrounding portion of the donut-like elastic member 181 are elastically deformed. Due to the elastic deformation of the donut-like elastic member 181, a pressing force is applied to press the inner peripheral surface of the hole of the donut-like elastic member 181 toward the outer peripheral surface of the shaft 182. By this applied pressure, a frictional force acting in a direction to suppress relative rotation acts between the inner peripheral surface of the hole of the donut-like elastic member 181 and the outer peripheral surface of the shaft 182 when relative rotation occurs. Then, a rotational load is applied to the intermediate 140 via the donut-like elastic member 181 fixed to the inner peripheral surface.
Then, the friction force applied to the intermediate body 140 by the axial circumferential surface type rotational load applying mechanism 180 is arranged in the vicinity of the shaft center of the intermediate body 140 and the outer peripheral surface of the shaft 182 of the drive side member 131 and the donut-like elasticity. The inner peripheral surface of the hole of the member 181 is used. For this reason, the variation in the moment due to the variation in the applied frictional force can be made smaller than the configuration in which the frictional force is applied outside the intermediate body 140 as in the configuration described in the first embodiment.

  Thus, by applying a frictional force to the intermediate body 140, substantially the same effects as those of the second to fourth embodiments can be obtained. In addition, a stable frictional force can be applied to the intermediate body 140, and vibration due to looseness of the meshing portion (fitting portion) can be further suppressed. In addition, there is a merit that the meshing portions at both ends of the intermediate body 140 can mesh with the driving side member 131 and the driven side member 132 with a substantially uniform force.

  Further, the rotational load applied to the intermediate body 140 by the spring-type rotational load applying mechanism 160 is a rotational load when the intermediate body 140 rotates relative to at least one of the driving side member 131 and the driven side member 131. It is. Therefore, the spring-type rotational load applying mechanism 160 causes the intermediate body 140 that rotates relative to at least one of the driving side member 131 and the driven side member 132 to rotate in any direction around the rotation axis. Even at times, a rotational load can be applied.

In the above-described embodiment, an example in which the present invention is applied to a drive transmission device having a spline-type joint having an intermediate transmission member has been described. However, the present invention is not limited to such a configuration. Absent. For example, the present invention can also be applied to a drive transmission device having an Oldham coupling having an intermediate transmission member and having a predetermined gap in a key to be fitted and a key groove.
Further, the configuration in which the driving side member is directly connected to the output shaft of the driving source and the driven side member is directly connected to the input shaft of the rotated body has been described, but the present invention is not limited to such a configuration. Absent. For example, the present invention can also be applied to a configuration in which an output shaft of a drive source and an input shaft of a rotated body are connected via other constituent members such as one or a plurality of transmissions. Also applicable to a configuration in which the drive side member is formed integrally with the drive side output shaft, the component of the transmission, and the driven side member is formed integrally with the component of the driven body of the driven side. It is.

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)
A driving side member such as a driving side member 131 connected coaxially to an output shaft such as a driving side output shaft 123 and a driven side member 132 connected coaxially to an input shaft such as a driven drum driving shaft 91. A coupling 130 having a driven side member such as an intermediate transmission member such as an intermediate body 140 fitted to the driving side member and the driven side member approximately coaxially with a play such as a predetermined play. In a drive transmission device such as the drive transmission device 115 that transmits the rotational driving force of the output shaft to the input shaft via the joint, at least one of the intermediate transmission member is transmitted when the rotational driving force is transmitted. A rotational load applying mechanism such as a brake mechanism 150 for applying a rotational load in the direction is provided.
According to this, as described in the first embodiment, the coupling 130 such as the coupling 130 having the intermediate transmission member such as the intermediate body 140 is provided, and the output shaft such as the driving side output shaft 123 and the driven side are provided. Absorbs the eccentricity, declination, and axial misalignment of the rotating shaft with the input shaft such as the drum driving shaft 91, and causes play in the engaging portion such as the meshing portion without lowering the rotational rigidity. Thus, it is possible to provide a driving force transmission device such as the drive transmission device 115 that can suppress the generated vibration.

(Aspect B)
In (Aspect A), the joint such as the coupling 130 is rotated by a driving force applied to a fitting portion such as a meshing portion of the driven member such as the driven member 131 and the driven member such as the driven member 132. And a spline type joint having outer teeth or inner teeth for transmitting a rotational driving force to the fitting portion of the intermediate transmission member.
According to this, as described in the first embodiment, the transmittable rotational torque can be increased, and the latent image of the photosensitive drum 40 or the like having a relatively large rotational load in the image forming apparatus such as the multi-function device 500 can be obtained. The present invention can also be applied to rotation driving of a driving roller such as a support roller 34 that rotates and drives an image carrier and an intermediate transfer member such as the intermediate transfer belt 15.

(Aspect C)
In (Aspect A) or (Aspect B), the rotational load imparted to the intermediate transmission member such as the intermediate body 140 by the rotational load imparting mechanism such as the brake mechanism 150 is applied to the driving side member such as the driving side member 131 and It is generated by a frictional force between at least one of the driven side members such as the driving side member 132 or the intermediate transmission member and a friction member such as the driving side member 131 included in the rotational load applying mechanism. is there.
According to this, as described in the first embodiment (1 to 5), with a rotational load applying mechanism having a simple configuration such as the brake mechanism 150, the rigidity of the teeth and the rotational load at each meshing portion of the coupling portion. It is possible to acquire in parallel the brake function by the brake mechanism 150 that is the applying mechanism and the damper function by the viscosity of the brake pad 152 that is the friction member.

(Aspect D)
In any one of (Aspect A) to (Aspect C), the rotational load applied to the intermediate transmission member such as the intermediate body 140 by the rotational load applying mechanism such as the spring-type rotational load applying mechanism 160 is the drive side member 131 or the like. It is a rotational load when the intermediate transmission member rotates relative to at least one of the driven side members such as the driven side member and the driven side member 132.
According to this, as described in the second embodiment (2 to 5), the drive side member such as the drive side member 131 and the driven side member 132 are provided by the rotational load applying mechanism such as the spring type rotational load applying mechanism 160. The intermediate transmission member such as the intermediate body 140 that rotates relative to at least one of the driven side members such as the rotation member can be subjected to a rotational load even when rotating in any direction around the rotation axis. .

(Aspect E)
In (Aspect D), the intermediate transmission member such as the intermediate body 140 is formed with a hollow portion having a circular hollow cross section that is open at least on one end side, coaxially with the rotation axis thereof, and is rotated by a spring. The rotational load applying mechanism such as the load applying mechanism 160 is provided so as to be in a region of the hollow portion formed in the intermediate transmission member when projected onto a plane perpendicular to the rotation axis of the intermediate transmission member. The rotational load applied to the intermediate transmission member by the rotational load applying mechanism is at least one of the driving side member such as the driving side member 131 and the driven side member such as the driven side member 132 and the friction member 163. It is generated by a frictional force with the friction member.
According to this, as described in the second embodiment (2 to 5), the rotation load applying mechanism is an intermediate portion caused by the fluctuation of the frictional force as compared with the configuration in which the rotation load applying mechanism is provided outside the intermediate transmission member such as the intermediate body 140. It is possible to reduce the fluctuation of the moment about the axis of the transmission member. Therefore, it is possible to reduce the generation of local force acting on the fitting portion such as the meshing portion and stably apply the rotational load generated by the frictional force to the intermediate transmission member. Variations can be suppressed.
Further, by providing a rotational load application mechanism such as the spring-type rotational load application mechanism 160 in the hollow formed in the intermediate transmission member, compared to the configuration provided outside the intermediate transmission member, the component members provided on the apparatus main body side, A driving force transmission device such as the drive transmission device 115 can be downsized.

(Aspect F)
In (Aspect D) or (Aspect E), the frictional force that causes the rotational load applied to the intermediate transmission member such as the intermediate body 140 by the rotational load applying mechanism such as the spring-type rotational load applying mechanism 160 is rotated. At least one of the friction member such as the friction member 163 disposed in the vicinity of the end of the rotation axis of the intermediate transmission member, and the driven side member such as the driven side member 132 and the driven side member 132. It is characterized by the frictional force.
According to this, as described in the second embodiment (2 to 4), the frictional force that causes the rotational load applied to the intermediate transmission member such as the intermediate body 140 is applied to the driving side and the driven side of the intermediate transmission member. In the vicinity of at least one of the ends. That is, a compression coil spring 162 that generates a frictional force between at least one of the driving side member such as the driving side member 131 and a driven side member such as the driven side member 132 and a friction member such as the friction member 163. By applying the pressure applied by the elastic member in parallel with the axis of the intermediate transmission member, the intermediate transmission member can be prevented from receiving a force due to the pressure in a direction perpendicular to the axis. Therefore, an effect similar to that of (Embodiment E) can be achieved.

(Aspect G)
In (Aspect F), the frictional force that causes the rotational load applied to the intermediate transmission member such as the intermediate body 140 by the rotational load applying mechanism such as the spring-type rotational load applying mechanism 160 is the driving force of the drive side member 131 or the like. It is generated by pressurizing a friction member such as the friction member 163 by the elastic force or magnetic force of the elastic member such as the compression coil spring 162 to at least one of the driven side member such as the side member and the driven side member 132. To do.
According to this, as described in the second embodiment (2 to 4), the opposing inner wall is different from the fitting portion of the driving side member such as the driving side member 131 and the driven side member such as the driven side member 132. A rotational load can be applied to the intermediate transmission member such as the intermediate body 140 by obtaining a frictional force by a composite configuration by contact between the portion such as the friction member and the friction member such as the friction member 163, and driving of the drive transmission device 115 and the like. It is possible to reduce the size of the transmission device.

(Aspect H)
In (Embodiment E), when the rotational load is applied to the intermediate transmission member such as the intermediate body 140 by the rotational load applying mechanism such as the axial circumferential surface rotational load applying mechanism 180, the rotational axis of the intermediate transmission member rotates. In the vicinity of the center in the longitudinal direction.
According to this, as described in the fifth embodiment, a stable frictional force can be generated and a rotational load can be applied to the intermediate transmission member such as the intermediate body 140, and the backlash of the fitting portion such as the meshing portion can be reduced. The vibration caused by the can be more stably suppressed. Further, there is a merit that the fitting portions at both ends of the intermediate transmission member can be engaged with the driving side member such as the driving side member 131 and the driven side member such as the driven side member 132 with a substantially uniform force. .

(Aspect I)
In any one of (Aspect A) to (Aspect H), a driven member such as a driven photosensitive drum 40 connected to the input shaft such as the drum driving shaft 91 or a photosensitive member including the driven member. In order to prevent the intermediate transmission member such as the intermediate body 140 from falling off due to the attaching / detaching operation of the unit such as the drum unit 90, a fall prevention mechanism such as a detent 156 for regulating the position of the intermediate transmission member is provided. It is a feature.
According to this, as described in the first embodiment (1 to 5), the detent 156 is formed on the brake arm 151 of the rotational load applying mechanism such as the brake mechanism 150, and the intermediate transmission member such as the intermediate body 140 is formed. By restricting the movement in the thrust direction, it has a function of preventing the intermediate transmission member from dropping due to the action of the thrust force accompanying the attachment / detachment when the unit such as the photosensitive drum unit 90 is attached / detached to / from the apparatus main body. be able to. Accordingly, when the unit is mounted again after being removed, the coupling such as the coupling 130 can be correctly connected, and the transmission function of the rotational driving force of the coupling can be normally functioned.

(Aspect J)
In a drive device such as a drum drive device 110, which includes a drive source such as the drive motor 121 and a drive transmission device that transmits the rotational drive force output from the drive source directly or at a speed to the rotated body. As the transmission device, a drive transmission device such as the drive transmission device 115 of any one of (Aspect A) to (Aspect I) is provided.
According to this, as described in each of the above embodiments, it is possible to provide a driving device such as the drum driving device 110 that can achieve the same effects as any of (Aspect A) to (Aspect I).

(Aspect K)
In an image forming apparatus such as a multi-function device 500 including a rotated body such as the photosensitive drum 40 and a driving device that rotationally drives the rotated body, the drum driving device 110 according to (Aspect J) or the like is used as the driving device. It is characterized by comprising the above drive device.
According to this, as described in the present embodiment, it is possible to provide an image forming apparatus such as the multi-function device 500 that can achieve the same effects as (Aspect J).

DESCRIPTION OF SYMBOLS 15 Intermediate transfer belt 19 Secondary transfer apparatus 20 Tandem type image forming part 23 Secondary transfer roller 28 Reversing apparatus 30 Document base 31 Exposure apparatus 34, 35 Support roller 36 Secondary transfer backup roller 37 Belt cleaning unit 38 Image forming unit 40 Photosensitive Body drum 42 paper feed roller 43 paper bank 44 paper feed cassette 45 separation roller 46 paper feed path 47 transport roller pair 48 paper feed path 49 registration roller pair 55 switching claw 56 discharge roller pair 57 paper discharge tray 60 fixing device 62 primary transfer Device 66 Heating roller 67 Pressure roller 70 Developing device 71 Developing roller 85 Charging device 86 Photoconductor cleaning device 90 Photoconductor drum unit 91 Drum drive shaft 92 Drum holder 94 Lock pin 100 Image forming unit 110 Drum drive device 115 Drive Reaching device 120 Drive unit 121 Drive motor 122 End plate 123 Output shaft 130 Coupling 131 Drive side member 132 Driven side member 140 Intermediate body 142 Brake disk 143 Fallout prevention ring 150 Brake mechanism 151 Brake arm 152 Brake pad 153 Holding member 154 Adjustment Screw 156 Detent 157 Brake holding mechanism 160 Spring-type rotational load applying mechanism 161 Protrusion 162 Compression coil spring 163 Friction member 164 Low-hardness rubber 166 Rubber-type rotational load-applying mechanism 166 Low-hardness rubber 170 Magnetic-type rotational load applying mechanism 171 Friction sheet 172 First magnetic body 173 Second magnetic body 180 Shaft circumferential surface type rotational load applying mechanism 181 Donut-shaped elastic member 182 Shaft 183 Spacer 184 Stopper 200 Paper feed table 300 Scanner 301 Contact Glass 303 First Traveling Body 304 Second Traveling Body 305 Imaging Lens 306 Reading Sensor 400 Automatic Document Conveying Device 500 Multifunction Machine P Sheet

JP-A-11-338211 JP 2002-340005 A

Claims (11)

A driving side member connected coaxially to the output shaft on the driving side, a driven side member connected coaxially to the input shaft on the driven side, and a predetermined play on each of the driving side member and the driven side member. A drive transmission device comprising a joint having an intermediate transmission member fitted substantially coaxially, and transmitting the rotational driving force of the output shaft to the input shaft via the joint;
A drive transmission device comprising a rotational load applying mechanism for applying a rotational load in at least one direction to the intermediate transmission member when transmitting rotational driving force. The drive transmission device according to claim 1,
The joint has internal teeth or external teeth that transmit a rotational driving force to the fitting portion of the driving side member and the driven side member, and an outer portion that transmits the rotational driving force to the fitting portion of the intermediate transmission member. A drive transmission device characterized by being a spline type joint having teeth or internal teeth. The drive transmission device according to claim 1 or 2,
The rotational load imparted to the intermediate transmission member by the rotational load imparting mechanism is a friction between at least one of the driving side member and the driven side member, or the intermediate transmission member, and a friction member included in the rotational load imparting mechanism. A drive transmission device generated by force. In the drive transmission device according to any one of claims 1 to 3,
The rotational load imparted to the intermediate transmission member by the rotational load imparting mechanism is a rotational load when the intermediate transmission member rotates relative to at least one of the driving side member and the driven side member. A drive transmission device characterized by that. The drive transmission device according to claim 4, wherein
In the intermediate transmission member, a hollow portion having a circular hollow cross section that is open at least at one end side is formed coaxially with the rotation axis.
The rotational load applying mechanism is provided so as to be in a region of the hollow portion formed in the intermediate transmission member when projected onto a plane perpendicular to the rotation axis of the intermediate transmission member,
The drive transmission device according to claim 1, wherein the rotational load applied to the intermediate transmission member by the rotational load application mechanism is generated by a frictional force between at least one of the driving side member and the driven side member and the friction member. In the drive transmission device according to claim 4 or 5,
The frictional force that causes the rotational load applied by the rotational load applying mechanism to the intermediate transmission member is
A drive transmission device characterized by a frictional force between the friction member disposed in the vicinity of an end portion of a rotation axis of the rotating intermediate transmission member and at least one of the driving side member and the driven side member. The drive transmission device according to claim 6, wherein
The frictional force that causes the rotational load applied by the rotational load applying mechanism to the intermediate transmission member is
The drive transmission device is generated by pressurizing a friction member by an elastic force or a magnetic force of an elastic member to at least one of the driving side member and the driven side member. The drive transmission device according to claim 5, wherein
Giving a rotational load to the intermediate transmission member by the rotational load imparting mechanism,
The drive transmission device, which is performed in the vicinity of the center in the longitudinal direction of the rotational axis of the rotating intermediate transmission member. In the drive transmission device according to any one of claims 1 to 8,
A dropout that regulates the position of the intermediate transmission member so that the intermediate transmission member does not fall off due to the attachment / detachment operation of the driven-side driven body connected to the input shaft or the unit having the driven body. A drive transmission device comprising a prevention mechanism. In a drive device comprising: a drive source; and a drive transmission device that transmits the rotational drive force output by the drive source directly or at a variable speed to the rotated body.
A drive apparatus comprising the drive transmission apparatus according to any one of claims 1 to 9 as the drive transmission apparatus. In an image forming apparatus comprising a rotated body and a drive device that rotationally drives the rotated body,
An image forming apparatus comprising the drive device according to claim 10 as the drive device.

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