JP2018194174A - Drive transmission device and image formation device - Google Patents

Abstract

To provide a drive transmission device which can achieve reduction of weight and noise of the device, inhibit cost increase of the device, inhibit occurrence of abnormal noise between an internal gear and a support shaft, and inhibit wear between the internal gear and the support shaft, and to provide an image formation device.SOLUTION: A drive device transmits driving force of a development motor 52 to a rotating body such as a development roller through an internal gear such as a development internal gear 55. The internal gear is made of resin and rotatably supported by a support shaft such as a development drive pin 55a. A grease holding part that is a grease holding groove 155a for holding grease is provided adjacent to a slide portion S between the support shaft and the internal gear. The grease held by the grease holding part is supplied to the slide portion S between the support shaft and the internal gear.SELECTED DRAWING: Figure 12

Description

  The present invention relates to a drive transmission device and an image forming apparatus.

  In an image forming apparatus in a copying machine, a printer, a facsimile machine, or a complex machine thereof, many driving units are provided for an image forming operation, and are used for operations of a photoconductor and a transfer belt.

  Patent Document 1 describes a drive device in which a gear meshing with a motor gear of a drive motor is an internal gear. According to Patent Document 1, the gear meshing with the motor gear of the drive motor is an internal gear, whereby the meshing rate can be increased, vibration can be suppressed, and noise can be blocked by the internal gear. It is described.

  An object of the present invention is to provide a drive transmission device and an image forming apparatus that can suppress the generation of abnormal noise between a rotating body and a support shaft, and can suppress wear of the rotating body and a support shaft.

  In order to achieve the above object, a first aspect of the present invention is a drive transmission device having a rotating body having a motion transmitting portion and a support shaft that supports the rotating body, wherein the support shaft is in the axial direction. Support shaft side sliding portions are provided near both ends, and the rotating body has a support shaft insertion hole for inserting the support shaft, and faces the support shaft side sliding portion of the support shaft insertion hole. And the diameter of the support shaft insertion hole gradually increases from the vicinity of the rotation body side sliding portion toward the center in the axial direction of the support insertion hole. It is characterized by this.

  According to this invention, generation | occurrence | production of the noise of a rotary body and a support shaft can be suppressed, and abrasion of an internal gear and a support shaft can be suppressed.

1 is a diagram illustrating an outline of an image forming apparatus. (A) is a perspective view of a process cartridge, (b) is sectional drawing of a process cartridge. The perspective view of a drive device. The perspective view which shows the inside of a drive device. The schematic sectional drawing of a drive device. The motor side front view of a drive device. The perspective view which shows the state which removed the photoconductor gear and the photoconductor drive shaft. The schematic block diagram of a reinforcement board. The perspective view which shows the state which removed from the state shown in FIG. 7 the resin plate further provided with the reinforcement board, the image development idler gear, and the image development drive side coupling. Explanatory drawing explaining the sliding location with the development drive pin of a resin molding product provided with a development internal gear and a development driven gear. The perspective view of the development drive pin which has a grease holding | maintenance part. The principal part expanded sectional view of the periphery of the development drive pin of a drive device. The figure explaining the grease supply to a sliding location. The figure which shows the 1st modification of a development drive pin. The principal part expanded sectional view of the drive device using the development drive of the 1st modification. The perspective view which shows the developing drive pin of a 2nd modification. The figure explaining the position of the grease holding | maintenance part in the development drive pin of a 2nd modification.

FIG. 1 is a diagram showing an outline of an image forming apparatus according to an embodiment of the present invention.
An image reading apparatus 200 is attached to the upper part of the apparatus main body 100 of the copying machine as an image forming apparatus.

A process cartridge 1 is provided inside the apparatus main body 100.
FIG. 2A is a perspective view of the process cartridge, and FIG. 2B is a cross-sectional view of the process cartridge.
As shown in FIG. 2B, the process cartridge 1 includes a photosensitive member 10 that is a latent image carrier, a charging device 11 that is disposed around the photosensitive member 10 and that acts on the photosensitive member 10, and a developing device. 12 and a cleaning device 14. The process cartridge 1 is detachably attached to the apparatus main body 100. Since the photosensitive member 10, the charging device 11, the developing device 12, and the cleaning device 14 are unitized as the process cartridge 1, replacement and maintenance work is facilitated. Further, it is possible to maintain the positional accuracy between the members with high accuracy, and to improve the quality of the formed image.

  The charging device 11 serving as a charging unit applies a charging bias to apply a charge to the surface of the photoconductor 10 to uniformly charge the photoconductor 10, and an adhering material such as toner attached to the surface of the charging roller 11a. And a removing roller 11b to be removed.

  The developing device 12 as developing means has a first agent storage chamber V1 in which a first conveying screw 12b as developer conveying means is disposed. Further, it also has a second agent storage chamber V2 in which a second conveying screw 12c as a developer conveying means, a developing roller 12a as a developer carrying member, a doctor blade 12d as a developer regulating member, and the like are disposed. .

  In these two agent storage chambers V1 and V2, a developer which is a two-component developer including a magnetic carrier and a negatively chargeable toner is included. The first transport screw 12b is rotationally driven by a driving unit (not shown) to transport the developer in the first agent storage chamber V1 to the front side in the drawing. Then, the developer transported to the front side end portion of the first agent storage chamber V1 in the drawing by the first transport screw 12b enters the second agent storage chamber V2.

  The second transport screw 12c in the second agent storage chamber V2 is rotationally driven by a driving unit (not shown) to transport the developer to the back side in the drawing. In this manner, the developing roller 12a is disposed in a posture parallel to the second conveying screw 12c above the second conveying screw 12c that conveys the developer. The developing roller 12a includes a magnet roller fixedly disposed in a developing sleeve made of a non-magnetic sleeve that is rotationally driven.

  Part of the developer conveyed by the second conveying screw 12c is pumped up to the surface of the developing roller 12a by the magnetic force generated by a magnet roller (not shown) in the developing roller 12a. Then, after the layer thickness is regulated by a doctor blade 12d arranged so as to maintain a predetermined gap from the surface of the developing roller 12a, the layer thickness is regulated and conveyed to a developing region facing the photoconductor 10, and on the photoconductor 10 Toner is attached to the electrostatic latent image. By this adhesion, a toner image is formed on the photoreceptor 10. The developer that has consumed toner by development is returned to the second conveying screw 12c as the surface of the developing roller 12a moves. Then, the developer transported to the end of the second agent storage chamber V2 by the second transport screw 12c returns to the first agent storage chamber V1. In this way, the developer is circulated and conveyed in the developing device.

  Further, the developing device 12 includes a toner concentration sensor that detects the toner concentration of the developer in the first agent storage chamber V1. The toner concentration sensor measures the toner concentration of the developer from the magnetic permeability of the developer. When the toner concentration is low, the magnetic carrier is concentrated, so that the magnetic permeability is increased. When the value measured by the toner density sensor 124 exceeds the target value (threshold value), toner is supplied from the toner bottle 20 shown in FIG. 1, and the toner density is controlled to a constant density. The target value is determined based on the detection result obtained by detecting the toner adhesion amount of the toner pattern formed on the photoconductor 10 with an optical sensor (not shown).

  By such an operation, control is performed so that the reference pattern density on the photosensitive member is kept constant. However, when the toner in the toner bottle 20 runs out, the density reduction cannot be suppressed. In such a situation, the detection result of the toner pattern by the optical sensor is not improved despite the operation of supplying the toner from the toner bottle 20 for a predetermined period. Therefore, if the detection result of the toner pattern by the optical sensor is not improved despite the operation of replenishing the toner from the toner bottle 20, it is determined by means (not shown) that the toner has run out (toner end). (Or presumptive judgment).

  In addition, after the toner end is determined, the toner bottle 20 is replaced, and when the toner end recovery for supplying the toner in the replaced toner bottle 20 to the developing device 12 is performed, the following operation is performed. That is, the developing roller 12a and the conveying screws 12b and 12c are rotated in order to satisfactorily mix the replenished toner and the developer. At this time, in order to prevent the developer on the developing roller 12a from sliding unevenly, the photosensitive member 10 is also driven to rotate.

  The cleaning device 14 serving as a cleaning unit includes a cleaning blade 14 a that contacts the surface of the photoconductor 10 and scrapes off transfer residual toner attached to the photoconductor 10. In addition, a toner collection coil 14b is provided that conveys the collected toner collected in the collection unit W and collected by the cleaning blade 14a. The recovered toner transported by the toner recovery coil 14b is transported to the developing device 12 or the waste toner bottle 41 by a toner transport device (not shown).

  A transfer device 17 as a transfer unit shown in FIG. 1 includes a transfer roller 16, and the transfer roller 16 is pressed against and brought into contact with the peripheral surface of the photoconductor 10. Further, a thermal fixing device 24 as a fixing unit is provided above the transfer device 17. The thermal fixing device 24 includes a heating roller 25 and a pressure roller 26. Further, the apparatus main body 100 is provided with a laser writing device 21 as latent image forming means. The laser writing device 21 includes a laser light source, a scanning rotary polygon mirror, a polygon motor, an fθ lens, and the like. Further, the apparatus main body is provided with a plurality of sheet cassettes 22 for storing sheets S such as transfer paper and OHP film.

  When copying using the apparatus configured as described above, the user presses a start switch (not shown). Then, first, the contents of the original set on the image reading apparatus 200 are read. At the same time, the photoconductor 10 is rotated by a photoconductor drive motor (not shown), and the surface of the photoconductor 10 is uniformly charged by the charging device 11 using the charging roller 11a. Next, a writing process is executed using the laser writing device 21 by irradiating laser light according to the content of the original read by the image reading device 200. Then, after forming an electrostatic latent image on the surface of the photoconductor 10, toner is attached using the developing device 12 to visualize (develop) the electrostatic latent image.

  At the same time as the user presses the start switch, the selected sheet S is sent out by the calling roller 27 from the multistage sheet cassette 22. Next, the sheet is separated one by one by the supply roller 28 and the separation roller 29 and sent to the supply path R1. The sheet S sent to the supply path R <b> 1 is conveyed by the sheet conveyance roller 30 and is abutted against the registration roller 23 and stopped. The transfer roller 16 is sent to a transfer nip formed in contact with the photoconductor 10 in accordance with the rotation timing of the toner image that is visualized on the photoconductor 10.

  The toner image on the photoreceptor 10 is transferred to the sheet S fed to the transfer nip by the transfer device 17. The residual toner on the photoconductor 10 after the image transfer is removed and cleaned by the cleaning device 14, and the residual potential on the photoconductor 10 from which the residual toner has been removed is removed by a static elimination device (not shown). In preparation for the next image formation starting from the charging device 11.

  On the other hand, the sheet S after the image has been transferred is guided to the heat fixing device 24, passed between the heating roller 25 and the pressure roller 26, and conveyed to these rollers while applying heat and pressure to the toner. The image is fixed. Thereafter, the sheet S on which the image has been fixed is discharged onto the discharge stack unit 32 by the discharge roller 31 and stacked.

Next, features of the present embodiment will be described.
3 is a perspective view of the driving device 50 for driving the photosensitive member 10 and the developing roller, FIG. 4 is a perspective view showing the inside of the driving device 50, and FIG. 5 is a schematic sectional view of the driving device 50. It is.
The driving device 50 includes a photosensitive member motor 51, a developing motor 52, and a holding unit 60 that holds a drive transmission member such as a gear for transmitting the driving force of these motors.
The holding part 60 includes a resin housing 61, a metal bracket 62 as a first member, and a metal damping plate 63 as a second member.

  As shown in FIGS. 4 and 5, the photoconductor gear 53, the development internal gear 55, the development driven gear 56, and the development idler gear 57 are accommodated in the resin housing 61. Further, a member for driving and transmitting waste toner that has fallen into the waste toner bottle to a waste toner conveyance screw (not shown) for conveying the waste toner bottle 41 to the back side of the waste toner bottle 41 is also housed. Specifically, a conveyance drive gear 71, a conveyance drive pulley 72, a conveyance timing belt 73, a conveyance driven pulley 74, and a conveyance idler gear 75 are accommodated.

  The photoconductor gear 53 is fixed to a metal photoconductor drive shaft 53 a that is rotatably supported by the holding portion 60, and meshes with the motor gear 51 a of the photoconductor motor 51. One end of the photosensitive member driving shaft 53a passes through the bracket 62 and the damping plate 63 and is rotatably supported by the bracket 62, and the photosensitive member driving side coupling 54 is attached to the other end. The resin housing 61 is rotatably supported. The photoconductor driving side coupling 54 is connected to a photoconductor driven side coupling (not shown) fixed to the end of the rotating shaft of the photoconductor 10.

  The development internal gear 55 is rotatably supported by a metal development drive pin 55 a fixed to the resin housing 61, and meshes with the motor gear 52 a of the development motor 52. The development internal gear 55 and the development driven gear 56 disposed coaxially with the development internal gear 55 are integrally molded products of resin, and the development idler gear 57 is engaged with the development driven gear 56. The tip of the development drive pin 55 a is fitted to the bracket 62, and the tip is positioned on the bracket 62.

  A developing drive side coupling 58 is provided at the center of the developing idler gear 57. The developing drive side coupling 58 penetrates through the resin housing 61 and is rotatably supported by the resin housing 61. The development drive side coupling 58 is connected to a development driven side coupling (not shown) fixed to the end of the rotation shaft of the development roller 12a. The development idler gear 57 and the development drive side coupling 58 are integrally molded products of resin.

  Further, a conveyance drive gear 71 is also engaged with the motor gear 51 a of the photoconductor motor 51. A conveyance timing belt serving as a drive belt is formed by a conveyance drive pulley 72 integrally formed with the conveyance drive gear 71 by integral molding of resin and a conveyance driven pulley 74 integrally molded with the conveyance idler gear 75 by integral molding of resin. 73 is stretched. Further, instead of the conveyance timing belt 73, a conveyance V belt may be used, and the driving force may be transmitted by frictional force with each pulley.

  An integrally molded resin product having the transport drive gear 71 and the transport drive pulley 72 is rotatably supported by a metal transport drive pin 72 a fixed to the resin housing 61 at one end. The tip of the transport drive pin 72 a is fitted to the bracket 62, and the tip is positioned on the bracket 62. An integrally molded resin product having the transport idler gear 75 and the transport driven pulley 74 is rotatably supported by a metal transport driven pin 74 a fixed to the resin housing 61. The tip of the conveyance follower pin 74 a is fitted to the bracket 62, and the tip is positioned on the bracket 62.

  A part of the transport idler gear 75 is exposed from the side opening 61a of the resin housing 61 as shown in FIG. As shown in FIG. 5, a screw driving gear 76 fixed to one end of a screw shaft 77 a of the waste toner conveying screw meshes with the conveying idler gear 75 from the side opening 61 a.

  As shown in FIG. 3, one end of a ground plate 65 connected to the ground is screwed to the bracket 62 with a screw 83. One end of the ground electrode plate 64 is fixed to one end of the photosensitive member drive shaft 53 a penetrating from the bracket 62, and the other end of the ground electrode plate 64 is screwed to the bracket 62 with a screw 82. As a result, the photoconductor 10 is grounded via the photoconductor drive shaft 53a, the ground electrode plate 64, the bracket 62, and the ground plate 65.

FIG. 6 is a front view of the driving device 50 on the motor side.
As shown in FIG. 6, the damping plate 63 and the bracket 62 are overlapped with each other, and five edges of the damping plate 63 are fixed to the resin housing 61 via the bracket 62 with screws 81a to 81e. Yes. As a result, the bracket 62 and the vibration damping plate 63 are partially coupled at the five edge portions 81 a to 81 e of the vibration damping plate 63. The photosensitive motor 51 and the developing motor 52 are screwed to the bracket 62 with the vibration damping plate 63 interposed therebetween.

  The holding unit 60 of the driving device 50 holds a plurality of drive transmission members such as the photoconductor gear 53 and the development internal gear 55 and a large number of vibration members such as the photoconductor motor 51 and the development motor 52. There is a possibility that noise is generated by the vibration of these vibration members. The vibrations of the photoconductor motor 51 and the development motor 52 propagate to the vibration damping plate 63 that contacts them, and the vibration damping plate 63 is vibrated by the vibrations of the photoconductor motor 51 and the development motor 52. On the other hand, vibrations generated by a plurality of drive transmission members such as the photoconductor gear 53 and the development internal gear 55 are the photoconductor drive shaft 53a that contacts the bracket 62, the development drive pin 55a, the conveyance drive pin 72a, the conveyance follower pin 74a, and the like. It propagates to the bracket 62 via. Thereby, the bracket 62 vibrates.

  The bracket 62 and the damping plate 63 are overlapped and partially coupled at the five edges 81a to 81e of the damping plate 63 as shown in FIG. Therefore, the damping plate 63 and the bracket 62 do not vibrate together and vibrate individually. Specifically, the vibration damping plate 63 vibrates due to vibrations of the photoconductor motor 51 and the developing motor 52, and the bracket 62 vibrates due to vibrations of various drive transmission members such as gears housed in the resin housing 61. is there. And the vibration of the damping plate 63 and the bracket 62 interferes with each other at the part where the damping plate 63 and the bracket 62 are partially coupled (the five edges 81a to 81e of the damping plate 63). At this time, by adjusting the rigidity of the damping plate 63 and the bracket 62, the coupling location, and the like so as to produce a phase difference in which the vibration of the damping plate 63 and the vibration of the bracket 62 cancel each other at the coupling location. Vibration between the vibration plate 63 and the bracket 62 is reduced.

FIG. 7 is a perspective view showing a state in which the photoconductor gear 53 and the photoconductor drive shaft 53a are removed.
As shown in FIG. 7, a reinforcing plate 90 that is a reinforcing member that reinforces the resin housing 61 is screwed to the resin housing 61.

FIG. 8 is a schematic configuration diagram of the reinforcing plate 90.
As shown in FIG. 8, a development support shaft 91 that rotatably supports a resin molded product having a development idler gear 57 and a development drive side coupling 58 is fixed to the reinforcing plate 90. Further, the reinforcing plate 90 is provided with screw through holes 90a, 90b, 90c through which screws pass. Also, a long reference hole 92a and a round main reference hole 92b are provided. As shown in FIG. 7, the secondary reference hole 92 a and the main reference hole 92 b are fitted into the positioning protrusions 611 provided in the resin housing 61, whereby the reinforcing plate 90 is positioned in the resin housing 61.

As shown in FIG. 8B, the developing support shaft 91 is provided at the center of gravity of a polygon (triangular in the present embodiment) formed by connecting the fixing locations of the resin housing of the reinforcing plate 90.
By providing at this position, the force applied to the developing support shaft 91 can be evenly distributed to the three fixed locations, and the reinforcement plate 90 can be prevented from being twisted.

FIG. 9 is a perspective view showing a state in which the reinforcing plate 90 and the resin molded product including the development idler gear 57 and the development driving side coupling 58 are removed from the resin housing 61 from the state shown in FIG.
As shown in FIG. 9, the resin housing 61 stores a first storage recess 61 b in which the photosensitive member driving side coupling 54 is stored, a second storage recess 61 c in which the development idler gear 57 is stored, and a development driven gear 56. It has a third storage recess 61d. These storage recesses are connected, and a substantially central portion of the resin housing 61 is greatly recessed in the vertical direction in the figure. This greatly recessed portion is less rigid, and the resin housing 61 is easily deformed by the compressive force from the left and right directions in the figure. For this reason, as shown in FIG. 7, the reinforcing plate 90 is fixed to the resin housing 61 and reinforced in such a manner as to bridge between the large recesses in which the three storage recesses 61d are continuous. Thereby, the reinforcing plate 90 is stretched against the compressive force from the left-right direction in the drawing, and deformation of the resin housing 61 can be suppressed. Thereby, the resin housing can be made difficult to vibrate, and the vibration of the driving device 50 can be suppressed.

  In the present embodiment, the gear that meshes with the motor gear 52 a of the developing motor 52 is the developing internal gear 55. By using the internal gear, the meshing ratio with the motor gear 52a can be increased, and the occurrence of uneven rotation, noise and vibration can be suppressed.

  In the driving device of the present embodiment, each gear is formed of a resin having high lubricity such as POM (polyacetal) having excellent sliding characteristics. However, when the developing internal gear 55 is formed of a resin having high lubricity, Sufficient strength cannot be obtained. This is because the internal gear forms teeth on the inner peripheral surface of the cylinder, and is structurally less rigid than the external gear that forms teeth on the outer peripheral surface of the column. Moreover, since an external gear is inserted in the internal gear, it cannot be reinforced by providing a rib or the like inside. For this reason, the rigidity is inevitably lowered, and sufficient strength cannot be obtained.

  For this reason, in this embodiment, a resin molded product including the development internal gear 55 and the development driven gear 56 is formed of a highly rigid resin. However, the rigidity of the resin and the lubrication (sliding) property are in a trade-off relationship. When a resin molded product including the development internal gear 55 and the development driven gear 56 is formed of a highly rigid resin, the development drive pin 55a. And the slidability decreases. As a result, abnormal noise may occur between the resin molded product including the development internal gear 55 and the development driven gear 56 and the development drive pin 55a during drive transmission. Further, there is a risk that the development drive pin 55a of the resin molded product is worn out at an early stage.

  For this reason, in the present embodiment, a grease holding portion that holds grease is provided on the development drive pin 55a, and the grease held in the grease holding portion is a resin molded product including the development internal gear 55 and the development driven gear 56. It was made to supply to the sliding part with the development drive pin 55a. Hereinafter, it demonstrates concretely using drawing.

FIG. 10 is an explanatory view for explaining the sliding portion S with the development drive pin 55a of the resin molded product 550 having the development internal gear 55 and the development driven gear 56. FIG.
As shown in FIG. 10, the sliding portion S of the resin molded product 550 with the development drive pin 55a is near the end of the pin insertion hole 550a into which the development drive pin 55a of the resin molded product 550 is inserted. This is because the vicinity of the end of the pin insertion hole 550a can be accurately molded by the mold structure, but the center of the pin insertion hole 550a is inevitably caused by the mold structure, and the pin insertion hole 550a This is because the central portion of the is larger than the prescribed inner diameter. As a result, only the vicinity of the end portion of the pin insertion hole 550a to be molded with high precision comes into contact with and slides on the development drive pin 55a.

FIG. 11 is a perspective view of the development drive pin 55a having a grease holding portion, and FIG. 12 is an enlarged cross-sectional view of the main part around the development drive pin 55a of the drive device 50.
As shown in FIG. 11, the development driving pin 55a is formed with a grease holding groove 155a which is an annular grease holding portion adjacent to the sliding portion S1 with the pin insertion hole 550a in the axial direction. Further, the developing drive pin 55a includes a fitting portion 155b fitted to the resin housing 61 and a flange portion 155c that abuts against the surface of the resin housing 61 when the fitting portion 155b is fitted to the resin housing 61. Have.

FIG. 13 is a diagram for explaining grease supply to the sliding portion S. FIG.
As shown in FIG. 13, the diameter of the pin insertion hole 550a is widened as it goes to the center due to sink marks at the time of molding. For this reason, the gap between the developing drive pin 55a and the pin insertion hole 550a becomes narrower toward the sliding portion S. Therefore, the grease held in the grease holding groove 155a flows to the sliding portion S having a narrower gap due to the capillary phenomenon, and the grease is supplied to the sliding portion S. In this way, the grease in the grease holding groove 155a is supplied to the sliding portion S, whereby the sliding portion S is lubricated, and the friction between the developing drive pin 55a and the resin molded product 550 at the sliding portion is reduced. The Thereby, at the time of drive transmission, abnormal noise can be generated at the sliding portion S or wear of the sliding portion of the pin insertion hole 550a can be suppressed.

  Further, grease may be applied to the edge of the pin insertion hole 550a. As shown in FIG. 12, the edge on the developing roller side of the pin insertion hole 550a is in contact with the flange 155c of the development drive pin 55a, and slides with the flange 155c when driving is transmitted. In addition, the resin molded product 550 may move to the developing motor side. As shown in FIG. 12, the pin insertion hole 550 a protrudes toward the developing motor side with respect to the developing internal gear 55. For this reason, when the resin molded product 550 moves to the developing motor side, the end of the pin insertion hole 550a on the developing motor side comes into contact with the bracket 62, and slides with the bracket 62 when driving is transmitted. For this reason, slidability with the flange part 155c and the bracket 62 can be improved by applying grease to the edge of the pin insertion hole 550a.

FIG. 14 is a diagram showing a first modification of the development drive pin, and FIG. 15 is an enlarged cross-sectional view of a main part of the drive device 50 using the development drive pin 55a-1 of the first modification.
As shown in FIG. 14, the development drive pin 55a-1 of the first modification is recessed except for the sliding portion S1 with the pin insertion hole 550a, and the pins other than the sliding portion S1 with the pin insertion hole 550a. A portion facing the inner peripheral surface of the insertion hole 550a is a grease holding portion 155a-1.

  By adopting such a configuration, it is possible to hold more grease than when the grease holding portion 155a-1 is formed in an annular groove shape adjacent to the sliding portion S, and the sliding portion S can be maintained over time. Grease can be supplied. Thereby, the sliding location S can be lubricated with grease over time, and generation of abnormal noise and wear of the sliding location of the pin insertion hole 550a can be suppressed over time.

FIG. 16 is a perspective view showing the development drive pin 55a-2 of the second modification.
The development driving pin 55a-2 of the second modified example has a groove shape in which the grease holding portion 155a-2 is cut out in the axial direction.
In the second modification, when the development driving pin is molded from resin, it is preferable that the grease holding portion can be formed most easily in terms of the mold configuration.

FIG. 17 is a diagram illustrating the position of the grease holding unit 155a-2 in the development driving pin 55a-2 according to the second modification.
As shown in FIG. 17, in this second modification, it is preferable that the grease holding portion 155a-2 is disposed on the side where the motor gear 52a of the developing motor and the developing internal gear 55 are engaged with each other. More specifically, it is preferable that the grease holding portion 155a-2 be disposed on a line segment connecting the axial center O1 of the development driving pin 55a-2 and the meshing location K.
The pressure angle θ, which is the direction in which the teeth of the motor gear 52a of the developing motor transmit force to the teeth of the developing internal gear 55, is about 20 °. As a result, as shown in FIG. 17, the normal direction component f of the force transmitted from the teeth of the motor gear 52a to the teeth of the developing internal gear 55 is the direction in which the teeth of the developing internal gear 55 are separated from the teeth of the motor gear 52a. . As a result, the development internal gear 55 is pushed in the direction of the arrow f in the figure, and the motor gear 52a and the development internal gear 55 mesh with each other in the sliding portion S between the development drive pin 55a-2 and the pin insertion hole 550a. The contact pressure of the region M opposite to the side increases. At this time, when the grease holding portion 155a-2 is in the region M opposite to the side where the motor gear 52a and the developing internal gear 55 are engaged, the circumferential end of the grease holding portion 155a-2 causes the pin insertion hole 550a to There is a risk that the inner peripheral surface will be cut.

  On the other hand, as shown in FIG. 17, the grease holding portion 155a-2 is provided on the side where the motor gear 52a and the developing internal gear 55 of the developing motor mesh with each other, so that the inner peripheral surface of the pin insertion hole 550a is the grease holding portion 155a. -2 can be prevented from strongly hitting the circumferential end of -2. Thereby, it can suppress that the internal peripheral surface of the pin insertion hole 550a is shaved by the circumferential direction edge part of the grease holding | maintenance part 155a-2.

  In the above description, the grease holding portion is provided on the development drive pin 55a. However, the grease holding portion may be provided on the inner peripheral surface of the pin insertion hole 550a.

What has been described above is an example, and the present invention has a specific effect for each of the following aspects.
(Aspect 1)
In the drive transmission device that transmits the driving force of the driving source such as the developing motor 52 to the rotating body such as the developing roller 12a via the internal gear such as the developing internal gear 55, the internal gear is made of resin, and the developing driving pin 55a. A grease holding portion that holds the grease at a portion facing the internal gear of the support shaft and / or a portion facing the support shaft of the internal gear is provided.
The present applicant is developing a drive transmission device in which the internal gear is formed of resin, the support shaft is fixed to the frame in a non-rotatable manner, and the internal gear is rotatably supported directly on the support shaft without a bearing. By using the internal gear as a resin, it is possible to reduce the weight, the noise, and the friction compared to the metal gear.
Moreover, the internal gear in which teeth are formed on the inner peripheral surface of the cylinder is less rigid than the external gear in which teeth are formed on the outer peripheral surface of the column. For this reason, in the drive transmission device under development, the internal gear is formed of a resin having higher rigidity than the external gear.
However, the rigidity and the lubricity are in a trade-off relationship, and when the internal gear is formed of a highly rigid resin, the frictional force between the support shaft and the internal gear increases and the slidability decreases. As a result, there are problems such as abnormal noise generated when the internal gear slides on the support shaft, and wear of the internal gear and the support shaft.
For this reason, it can be considered that the internal gear is rotatably supported on the support shaft via the bearing. However, in this case, a bearing is required, and the number of parts increases and a new problem of increasing the cost of the apparatus occurs as compared with the case where the internal gear is directly supported on the support shaft in a freely rotatable manner.
It is also conceivable to fix the internal gear to the support shaft in a non-rotatable manner and to support the support shaft rotatably on the frame of the drive device without using a bearing. Since the frame of the drive device supports many members such as a drive motor and a drive transmission component, for example, it contains a glass fiber or the like, and it is necessary to increase the rigidity further than the internal gear. As described above, the frame has higher rigidity than the internal gear, so the lubricity is worse than that of the internal gear, and the slidability between the frame and the support shaft is that between the internal gear and the support shaft with increased rigidity. It is worse than For this reason, it is not possible to employ a configuration in which the internal gear is fixed to the support shaft so as not to rotate, and the support shaft is supported rotatably on the frame of the drive device without a bearing. Further, when the support shaft is rotatably supported on the frame of the drive device via a bearing, a bearing is required, which causes a problem that the cost of the device is increased.
According to (Aspect 1), when the internal gear is made of resin, it is possible to reduce the weight, noise, and wear of the drive transmission device as compared with the case where it is made of metal. In addition, by supporting the internal gear rotatably on the support shaft without using a bearing, the number of parts can be reduced, and the cost of the apparatus can be suppressed. Further, by rotatably supporting the internal gear on the support shaft, the internal gear can be rotated more favorably than when the support shaft on which the internal gear is fixed so as not to rotate is directly fixed to the frame of the apparatus.
Furthermore, by providing a grease holding portion that holds grease at a portion facing the internal gear of the support shaft and / or a portion facing the support shaft of the internal gear, the grease held by the grease holding portion is supported by the internal gear. The frictional force between the internal gear and the support shaft can be reduced by being supplied to the sliding portion with the shaft. Thereby, generation | occurrence | production of the noise when an internal gear slides with a support shaft can be suppressed. Moreover, wear of the internal gear and the support shaft can be suppressed.

(Aspect 2)
In (Aspect 1), a plurality of grease holding portions were provided.
According to this, the grease can be supplied from the plurality of grease holding portions to the sliding portion S between the internal gear such as the development internal gear 55 and the support shaft such as the development drive pin 55a.

(Aspect 3)
In (Aspect 1) or (Aspect 2), the grease holding portion is adjacent to the sliding portion between the support shaft such as the development drive pin 55 a and the internal gear such as the development internal gear 55.
According to this, as explained in the embodiment, the grease held in the grease holding portion can be satisfactorily supplied to the sliding portion.

(Aspect 4)
In any one of (Aspect 1) to (Aspect 3), the grease holding portion is a groove cut out along the circumferential direction.
According to this, the grease can be held in the groove cut out in the circumferential direction.

(Aspect 5)
In any one of (Aspect 1) to (Aspect 3), the grease holding portion is a groove cut out along the axial direction.
According to this, grease can be hold | maintained at the groove | channel notched along the axial direction. When the support shaft is resin, the grease holding portion can be formed with a simple mold structure.

(Aspect 6)
In (Aspect 5), when viewed from the axial direction, the grease holding portion is provided on the side where the internal gear such as the developing internal gear 55 and the external gear such as the motor gear 52a meshing with the internal gear are engaged.
According to this, as described with reference to FIG. 17, it is possible to prevent the portion facing the support shaft of the developing internal gear 55 from being scraped at the circumferential end of the groove cut out along the axial direction. can do.

(Aspect 7)
In any one of (Aspect 1) to (Aspect 6), one or a plurality of drive transmission members (this embodiment) for transmitting the drive from the internal gear such as the developing internal gear 55 and the rotating gear such as the developing roller 12a from the internal gear. In the embodiment, a housing such as a resin housing 61 that houses a development driven gear 56, a development idler gear 57, and the like is provided, and the housing portion that houses one or more drive transmission members of the housing is concave and has a concave shape. A reinforcing member such as a reinforcing plate 90 that is fixed to the housing so as to straddle the housing portion and reinforces the housing is provided.
According to this, as described in the embodiment, the rigidity of the housing such as the resin housing 61 can be increased, and deformation of the housing can be suppressed.

(Aspect 8)
In (Aspect 7), the reinforcing member such as the reinforcing plate 90 includes a drive transmission member support shaft such as a development support shaft 91 that rotatably supports a drive transmission member such as the development idler gear 57, and a housing such as the resin housing 61. The drive transmission member support shaft is provided at the position of the center of gravity of the polygon connecting the fixed portions.
According to this, as described with reference to FIG. 8B, the force applied to the drive transmission member support shaft such as the development support shaft 91 can be evenly distributed to the plurality of fixed portions, and the reinforcing plate 90 It is possible to suppress the twisting of the reinforcing member such as.

(Aspect 9)
The image forming apparatus includes the drive transmission device according to any one of (Aspect 1) to (Aspect 8).
According to this, it is possible to provide an image forming apparatus in which the apparatus can be reduced in weight and noise, and the cost of the apparatus can be suppressed.

10: Photoconductor 12a: Development roller 41: Waste toner bottle 50: Drive device 51: Photoconductor motor 51a: Motor gear 52: Development motor 52a: Motor gear 53: Photoconductor gear 53a: Photoconductor drive shaft 54: Photoconductor drive side cup Ring 55: Development internal gears 55a, 55a-1, 55a-2: Development drive pin 56: Development driven gear 57: Development idler gear 58: Development drive side coupling 60: Holding portion 61: Resin housing 61b: First storage recess 61c : Second storage recess 61d: third storage recess 62: bracket 71: transport drive gear 72: transport drive pulley 72a: transport drive pin 73: transport timing belt 74: transport driven pulley 74a: transport driven pin 75: Transport idler gear 76: screw drive gear 77a: screw shaft 90: reinforcing plates 90a, 90b, 90 : Screw through hole 91: development support shaft 92a: sub reference hole 92b: primary reference holes 155a, 155a-1,155a-2: grease holding portion (grease holding groove)
550: Resin molded product 550a: Pin insertion hole S: Sliding part S1: Sliding part with the developing drive pin insertion hole

Japanese Patent Laid-Open No. 11-311302

Claims (8)

In a drive transmission device having a rotator provided with a drive transmission unit, and a support shaft that supports the rotator,
The support shaft has a support shaft side sliding portion in the vicinity of both end portions in the axial direction,
The rotating body has a support shaft insertion hole into which the support shaft is inserted, and has a rotating body side sliding portion at a position facing the support shaft side sliding portion of the support shaft insertion hole,
The drive transmission device according to claim 1, wherein the diameter of the support shaft insertion hole gradually increases from the vicinity of the rotating body side sliding portion toward the vicinity of the center in the axial direction of the support insertion hole. In a drive transmission device having a rotator provided with a drive transmission unit, and a support shaft that supports the rotator,
The rotating body has a support shaft insertion hole for inserting the support shaft, and includes an inner peripheral cylindrical portion that constitutes the support shaft insertion hole, and an outer peripheral cylindrical portion that constitutes the drive transmission portion,
A connecting portion for connecting the outer peripheral cylindrical portion and the inner peripheral cylindrical portion in the radial direction of the rotating body;
The diameter of the support shaft insertion hole gradually increases from the vicinity of the axial end portion of the support shaft insertion hole toward the junction of the connecting portion and the inner peripheral cylindrical portion. apparatus. The drive transmission device according to claim 2, wherein
The drive transmission device, wherein the connecting portion is formed integrally with the inner peripheral cylindrical portion and the outer peripheral cylindrical portion. The drive transmission device according to claim 2 or 3,
The drive transmission device according to claim 1, wherein the connecting portion is coupled to the inner peripheral cylindrical portion in the vicinity of the center of the axial length of the inner peripheral cylindrical portion. The drive transmission device according to any one of claims 1 to 4,
The drive transmission device according to claim 1, wherein the support shaft includes an annular protrusion that abuts against an end portion of the support shaft insertion hole. The drive transmission device according to any one of claims 1 to 5,
The rotating body is a two-stage gear, and the diameter of one gear is smaller than the diameter of the other gear. The drive transmission device according to claim 6, wherein
The other transmission gear of the rotating body includes an external tooth.   An image forming apparatus comprising the drive transmission device according to claim 1.

Images