Clutch device and image forming apparatus

Abstract

To provide a clutch device and an image forming device capable of effectively preventing vibration of a planetary gear, by restraining abrasion of either or both of the planetary gear and a support shaft.SOLUTION: The clutch device 200 includes the input gear 210 having the input gear portion 211 and the sun gear portion 212, the carrier 220 having the plurality of planetary gears 222 to 222 and the locked portion 221, the output gear 230 having the internal tooth portion 231 and the external tooth portion 232, and the locking device 300 having the locking portion 310, transmits the rotational force F to the output gear 230 in a state where the locking portion 310 is at the locking position, and does not transmit the rotational force F to the output gear 230 in a state where the locking portion 310 is at the locked position. The outer peripheral surface of each of the support shafts 223 to 223 is provided with a cutout portion 223a for forming a lubricant holding space SP, which is a space for holding the lubricant, between the outer peripheral surface and each of the planetary gears 222 to 222.SELECTED DRAWING: Figure 11

Description

[Technical Field]

[0001] The present disclosure relates to a clutch device and an image forming apparatus such as a copier, a multifunction device, a printer, and a facsimile machine. [Background technology]

[0002] A clutch device has been known in the art that transmits the rotational force of the input gear to the output gear in an engaged state where the engaged portion of the carrier is engaged with the engaging portion of the locking device, and that releases the transmission of the rotational force of the input gear to the output gear in an unlocked state where the engaged state of the engaged portion of the carrier with the locking portion of the locking device is released (see, for example, Patent Document 1).

[0003] 18 and 19 are exploded perspective views of an example of a conventional clutch device 200X as viewed from the carrier 220X side and the input gear 210 side, respectively.

[0004] As shown in FIGS. 18 and 19, the conventional clutch device 200X includes an input gear 210, a carrier 220X, and an output gear 230.

[0005] The input gear 210 has an input gear portion 211 and a sun gear portion 212. The input gear portion 211 receives a rotational force F from a rotation drive portion (not shown) and rotates around a first rotation axis α1. The sun gear portion 212 has a smaller diameter than the input gear portion 211 and rotates together with the input gear portion 211 around the first rotation axis α1.

[0006] The carrier 220X is a rotating body that can rotate around a first rotation axis α1, and has a plurality of (three in this example) planetary gears 222-222, a plurality of support shafts 223X-223X, and one or a plurality of (six in this example) locked portions 221-221. The locked portions 221-221 are portions for stopping the rotation of the carrier 220X around the first rotation axis α1, and are formed as wall portions that extend along both the rotation axis direction W of the carrier 220X and the radial direction E centered on the first rotation axis α1.

[0007] The planetary gears 222-222 mesh with the sun gear portion 212. The plurality of support shafts 223X-223X support the plurality of planetary gears 222-222 so as to be rotatable about second rotation axes α2 that extend along the first rotation axis α1.

[0008] The output gear 230 has an internal tooth portion 231 and an external tooth portion 232. The internal tooth portion 231 meshes with the plurality of planetary gears 222 on the inner side in the radial direction E centered on the first rotation axis α1. The external tooth portion 232 transmits a rotational force F on the outer side in the radial direction E.

[0009] The locking device 300 (electromagnetic solenoid unit) has a locking portion 310 (carrier arm) that can move between a locking position where it is locked to the locked portion 221 to rotate / stop the carrier 220X, and a non-locking position where it is not locked to the locked portion 221.

[0010] The clutch device 200X transmits the rotational force F to the output gear 230 when the locking portion 310 is in the locking position, and does not transmit the rotational force F to the output gear 230 when the locking portion 310 is in the non-locked position. [Prior art documents] [Patent documents]

[0011] [Patent Document 1] Patent Publication No. 2021-85889 Summary of the Invention [Problem to be solved by the invention]

[0012] In such a conventional clutch device 200X, loads are likely to be applied to the planetary gears 222-222 and the support shafts 223X-223X, and in this case, one or both of the planetary gears 222-222 and the support shafts 223X-223X may wear. As a result, when the planetary gears 222-222 rotate around the second rotation axis α2, the rotation center of the planetary gears 222-222 is shifted, causing the planetary gears 222-222 to vibrate, which is an inconvenience. This is particularly noticeable when the planetary gears 222-222 and the support shafts 223X-223X are made of resin.

[0013] Therefore, the present disclosure aims to provide a clutch device and an image forming apparatus that can suppress wear of either or both of the planetary gear and the support shaft, thereby effectively preventing vibration of the planetary gear. [Means for solving the problem]

[0014] In order to solve the above-mentioned problems, the clutch device according to the present disclosure includes an input gear having an input gear portion that receives a rotational force from a rotary drive portion and rotates about a first rotation axis, and a sun gear portion that has an outer diameter smaller than that of the input gear portion and rotates about the first rotation axis together with the input gear portion; a carrier that is a rotating body rotatable about the first rotation axis, the carrier having a plurality of planet gears that mesh with the sun gear portion, a plurality of support shafts that support each of the plurality of planet gears rotatably about a second rotation axis along the first rotation axis, and a locked portion for stopping the rotation about the first rotation axis; a clutch device comprising: an output gear that is a rotatable gear and has internal teeth that mesh with the plurality of planetary gears and external teeth that transmit the rotational force; and a locking device having a locking portion that is movable between a locking position where it is locked to the locked portion and a non-locking position where it is not locked to the locked portion, wherein the clutch device transmits the rotational force to the output gear when the locking portion is in the locking position and does not transmit the rotational force to the output gear when the locking portion is in the non-locked position, and wherein an outer peripheral surface of the support shaft is provided with a notch for forming a lubricant retaining space that retains a lubricant between the support shaft and the planetary gear. [Effects of the Invention]

[0015] According to the present disclosure, wear of either or both of the planetary gear and the support shaft can be suppressed, thereby making it possible to effectively prevent vibration of the planetary gear. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a cross-sectional view showing a schematic configuration of an image forming apparatus including a clutch device according to an embodiment of the present invention. [Figure 2] 2 is a cross-sectional view showing an image forming section, a primary transfer belt device, and a secondary transfer device in the image forming apparatus shown in FIG. 1. [Figure 3] FIG. 2 is a perspective view of a gear train portion on the front side of a drive device that drives an image forming unit and a primary transfer belt device, as viewed from the front side. [Figure 4] 4 is a perspective view showing a gear train portion on the front side of the drive device shown in FIG. 3 together with one developing device. [Figure 5] 10 is a front view showing a state in which the clutch device is turned on in the rear-side gear train portion of the drive device with the front-side gear train removed. FIG. [Figure 6] 10 is a front view showing a state in which the clutch device is disengaged in the rear gear train portion of the drive device with the front gear train removed. FIG. [Figure 7] FIG. 6 is a perspective view showing a clutch device portion of the drive unit shown in FIG. 5. [Figure 8] FIG. 7 is a perspective view showing a clutch device portion of the drive unit shown in FIG. 6. [Figure 9] 2 is an exploded perspective view showing an input gear, a carrier, and an output gear in an example of a clutch device according to the present embodiment. FIG. [Figure 10] FIG. 10 is an exploded perspective view showing a state in which the output gear is attached to the input gear in FIG. 9. [Figure 11] 3 is an exploded perspective view showing a state in which some planetary gears are removed from support shafts in the carrier of the clutch device according to the first embodiment. FIG. [Figure 12] 3 is a front view showing a state in which some planetary gears are removed from support shafts in the carrier of the clutch device according to the first embodiment. FIG. [Figure 13] 10 is a cross-sectional view showing how the lubricant held in the lubricant holding space by the notch is pushed out into the gap between the carrier and the planetary gear and the gap between the output gear and the planetary gear. FIG. [Figure 14] FIG. 10 is an enlarged rear view showing an example of a cutout provided in a support shaft in a clutch device according to a second embodiment, at a position away from the center of the second rotation axis in an orthogonal direction perpendicular to the radial direction along an imaginary line connecting the second rotation axis and the first rotation axis. [Figure 15] FIG. 10 is an enlarged rear view showing an example of a cutout provided in a support shaft of a clutch device according to a second embodiment, at a position radially spaced from the center of the second rotation axis along an imaginary line connecting the second rotation axis and the first rotation axis. [Figure 16]FIG. 11 is an exploded perspective view showing a state in which some planetary gears are removed from support shafts in a carrier of a clutch device according to a third embodiment. [Figure 17] FIG. 11 is a front view showing a state in which some planetary gears are removed from support shafts in the carrier of the clutch device according to the third embodiment. [Figure 18] FIG. 10 is an exploded perspective view of an example of a conventional clutch device, as viewed from the carrier side. [Figure 19] FIG. 1 is an exploded perspective view of an example of a conventional clutch device, as viewed from the input gear side. DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the following description, the same components are denoted by the same reference numerals. The names and functions of the components are also the same. Therefore, detailed descriptions thereof will not be repeated.

[0018] [Image forming apparatus] 1 is a cross-sectional view showing a schematic configuration of an image forming apparatus 100 according to the present embodiment. In the figure, the width direction is designated as X, the left side as X1, the right side as X2, the direction perpendicular to the width direction X as the depth direction Y, the front side as Y1, the back side as Y2, and the up-down direction perpendicular to the width direction X and the depth direction Y as Z, in the following description.

[0019] The image forming apparatus 100 is a multifunction machine having a copy function, a scanner function, a facsimile function, and a printer function, and transmits to the outside an image of an original G read by the image reading device 102. The image forming apparatus 100 also forms an image of the original G read by the image reading device 102 or an image received from the outside on a sheet P such as paper in color or monochrome.

[0020] The image reading device 102 includes a document placing table 130a (document setting table) on which a document G is placed, and an image reading unit 130 that reads the document G placed on the document placing table 130a. The image reading unit 130 moves a scanning optical system 130c in the scanning direction, thereby reading the image of the document G placed on the document placing table 130a with a document reading unit 130b and creating image data.

[0021] The image reading device 102 further includes a document feeder 160. The document feeder 160 is supported above the image reading unit 130 so as to be openable and closable relative to the image reading unit 130. The document feeder 160 transports one or more documents G one by one to the image reading position 130d. The documents G transported to the image reading position 130d are read by the document reading unit 130b via the scanning optical system 130c stopped at the image reading position 130d, and image data is generated. As described above, the image reading unit 130 scans the scanning optical system 130c to read the documents G placed on the document placing table 130a with the document reading unit 130b, or reads the documents G transported by the document feeder 160 with the document reading unit 130b, and generates image data.

[0022] The image forming apparatus main body 101 includes an optical scanning device 1, developing devices 2y, 2m, 2c, and 2k, photosensitive drums 3y, 3m, 3c, and 3k, drum cleaning devices 4y, 4m, 4c, and 4k, chargers 5y, 5m, 5c, and 5k, a primary transfer belt device 70, a secondary transfer device 11, a fixing device 12, a sheet transport path S, a paper feed cassette 18, and a sheet discharge tray 141 (141a, 141b).

[0023] The image forming apparatus 100 primarily transfers a toner image formed using toners of multiple colors onto a belt 71 (a primary transfer belt in this example), and then secondarily transfers the toner image primarily transferred onto the belt 71 onto a sheet P.

[0024] In this embodiment, image data corresponding to a color image using yellow (Y), magenta (M), and cyan (C), or a monochrome image using a single color (e.g., black (K)) is handled. In the following description, yellow, magenta, cyan, and black will be simply referred to as Y, M, C, and K, respectively.

[0025] The image forming section 50 of the image forming apparatus 100 is provided with developing devices 2y, 2m, 2c, and 2k, photosensitive drums 3y, 3m, 3c, and 3k, drum cleaning devices 4y, 4m, 4c, and 4k, and chargers 5y, 5m, 5c, and 5k for forming four types of toner images, which correspond to Y, M, C, and K, respectively, and form four image stations Py, Pm, Pc, and Pk.

[0026] The chargers 5y, 5m, 5c, and 5k uniformly charge the surfaces of the photosensitive drums 3y, 3m, 3c, and 3k to a predetermined potential. The optical scanning device 1 exposes the surfaces of the photosensitive drums 3y, 3m, 3c, and 3k, which have been charged to a predetermined potential, to form electrostatic latent images. The developing devices 2y, 2m, 2c, and 2k develop the electrostatic latent images on the surfaces of the photosensitive drums 3y, 3m, 3c, and 3k with toner of each color to form toner images on the surfaces of the photosensitive drums 3y, 3m, 3c, and 3k. To this end, the developing devices 2y, 2m, 2c, and 2k include developing rollers 21y, 21m, 21c, and 21k that supply toner of each color to the surfaces of the photosensitive drums 3y, 3m, 3c, and 3k. The drum cleaning devices 4y, 4m, 4c, and 4k remove and collect residual toner remaining on the surfaces of the photosensitive drums 3y, 3m, 3c, and 3k after the primary transfer described below. Through the series of operations described above, toner images of each color are formed on the surfaces of the photosensitive drums 3y, 3m, 3c, and 3k.

[0027] The primary transfer belt device 70 includes a belt 71, primary transfer rollers 6y, 6m, 6c, and 6k, a plurality of belt tension rollers 72-72 (tension rollers including a drive roller 721, a driven roller 722, and a tension roller 723), and a belt cleaning device 9. The belt 71 is stretched over the plurality of belt tension rollers 72-72, and when a drive roller 721, one of the belt tension rollers 72-72, is driven to rotate by a drive device 400 (described later), the belt 71 rotates in a predetermined rotation direction R. At this time, the driven roller 722 and the tension roller 723 rotate following the rotation of the belt 71. The primary transfer rollers 6y, 6m, 6c, and 6k are provided inside the belt 71 to bring the belt 71 into contact with the surfaces of the corresponding photosensitive drums 3y, 3m, 3c, and 3k. The toner images of the respective colors formed on the surfaces of the photosensitive drums 3y, 3m, 3c, and 3k are primarily transferred onto the belt 71 by primary transfer rollers 6y, 6m, 6c, and 6k.

[0028] The secondary transfer device 11 has a secondary transfer roller 11a. The secondary transfer device 11 forms a transfer nip portion TN (transfer nip area) between the secondary transfer roller 11a and the belt 71, and conveys a sheet P conveyed through a sheet conveying path S by sandwiching it in the transfer nip portion TN. When the sheet P passes through the transfer nip portion TN, the toner image on the surface of the belt 71 is secondarily transferred onto the sheet P, and the sheet P is conveyed to the fixing device 12. The belt cleaning device 9 removes and collects waste toner that has not been transferred to the sheet P and remains on the surface of the belt 71.

[0029] The fixing device 12 includes a fixing roller 31 and a pressure roller 32 that rotate while sandwiching the sheet P. The fixing device 12 sandwiches the sheet P, onto which the toner image has been transferred, between the fixing roller 31 and the pressure roller 32, and applies heat and pressure to fix the toner image to the sheet P.

[0030] The paper feed cassette 18, which stores sheets P used for image formation, is provided below the optical scanning device 1. The sheet P is drawn out of the paper feed cassette 18 by a pickup roller 16 and conveyed to a sheet conveying path S. The sheet P conveyed to the sheet conveying path S passes through a secondary transfer device 11 and a fixing device 12, is conveyed to discharge rollers 17 (17a, 17b), and is discharged to a sheet discharge tray 141 (141a, 141b) in a discharge section 140. The sheet conveying path S is provided with a conveying roller 13, a registration roller 14, and discharge rollers 17 (17a, 17b). In this example, the discharge roller 17 is two discharge rollers 17a, 17b provided above and below, and the sheet discharge tray 141 is two sheet discharge trays 141a, 141b provided corresponding to the two discharge rollers 17a, 17b, respectively. The conveying rollers 13 promote the conveyance of the sheet P. The registration rollers 14 temporarily stop the sheet P and align the leading edge of the sheet P. The registration rollers 14 then transport the stopped sheet P in accordance with the timing of the toner image on the belt 71. The toner image on the belt 71 is secondarily transferred onto the sheet P at the transfer nip portion TN between the belt 71 and the secondary transfer roller 11a.

[0031] Although FIG. 1 shows one sheet feed cassette 18, the present invention is not limited to this, and a configuration may be provided in which a plurality of sheet feed cassettes 18 are provided, each of which may hold a different type of sheet P.

[0032] Furthermore, when forming an image on the back side of the sheet P in addition to the front side, the image forming apparatus 100 conveys the sheet P in the reverse direction from the upper discharge rollers 17b to the sheet inversion path Sr. The image forming apparatus 100 inverts the sheet P conveyed in the reverse direction and guides it again to the registration rollers 14. Furthermore, the image forming apparatus 100 forms an image on the back side of the sheet P guided to the registration rollers 14 in the same manner as on the front side, and conveys the sheet P to the sheet discharge tray 141 (141a, 141b).

[0033] FIG. 2 is a cross-sectional view showing the image forming unit 50, primary transfer belt device 70, and secondary transfer device 11 in the image forming apparatus 100 shown in FIG. 1. FIG. 3 is a perspective view of the front-side gear train (410, 420, 430) of the drive device 400 that drives the image forming unit 50 and primary transfer belt device 70, as viewed from the front side. FIG. 4 is a perspective view of the front-side gear train (410, 420, 430) of the drive device 400 shown in FIG. 3, along with one developing device 2y. FIGS. 5 and 6 are front views showing the rear-side gear train (440, 450) of the drive device 400 with the front-side gear train (410, 420, 430) removed, with the clutch device 200 in the on and off states, respectively. Additionally, FIGS. 7 and 8 are perspective views showing a portion of the drive device 400 and the clutch device 200 shown in FIGS. 5 and 6, respectively.

[0034] When forming a color image, the image forming apparatus 100 drives and rotates the belt 71, the photosensitive drums 3y, 3m, 3c, 3k, and the developing rollers 21y, 21m, 21c, 21k (an example of a developer carrier) of the developing devices 2y, 2m, 2c, 2k, and when forming a monochrome image, the image forming apparatus 100 drives and rotates the belt 71, the photosensitive drums 3y, 3m, 3c, 3k, and the developing roller 21k of the developing device 2k, but stops the rotation of the developing rollers 21y, 21m, 21c of the developing devices 2y, 2m, 2c.

[0035] Next, a detailed description will be given of a driving device 400 that drives and rotates the belt 71, the photosensitive drums 3y, 3m, 3c, and 3k, and the developing rollers 21y, 21m, 21c, and 21k of the developing devices 2y, 2m, 2c, and 2k.

[0036] The drive device 400 includes a rotation drive unit 401 (drive motor), a first gear train 410 (see FIG. 3), a second gear train 420 (see FIG. 3), a third gear train 430 (see FIG. 3), a fourth gear train 440 (see FIG. 5), and a fifth gear train 450 (see FIG. 5). The rotation drive unit 401 and the first gear train 410 to the fifth gear train 450 are supported by a main body frame FL and a sub-frame FL1 (see FIGS. 3 and 4) of the image forming apparatus main body 101. The sub-frame FL1 is attached to the main body frame FL. Here, the coupling gears 2ay, 2am, 2ac, and 2ak of the yellow, magenta, cyan, and black developing devices 2y, 2m, 2c, and 2k, the fourth intermediate gear 414 and the fifth intermediate gear 415 of the first gear train 410, and the fourth intermediate gear 424 and the fifth intermediate gear 425 of the second gear train 420 are supported by the sub-frame FL1. Note that Figures 5 and 6 show the first gear train 410 to the third gear train 430 and the sub-frame FL1 removed from the main frame FL.

[0037] 3 and 4, the first gear train 410 includes a first intermediate gear 411 to a fifth intermediate gear 415, and transmits a rotational force F from a rotation shaft 401a of the rotation drive unit 401 to a first photoconductor gear 3ay and a second photoconductor gear 3am, which rotate the two photoconductor drums 3y and 3m. The first intermediate gear 411 transmits the rotational force F from the rotation shaft 401a of the rotation drive unit 401 to a second intermediate gear 412. The second intermediate gear 412 transmits the rotational force F from the first intermediate gear 411 to a third intermediate gear 413. The third intermediate gear 413 transmits the rotational force F from the second intermediate gear 412 to a fourth intermediate gear 414 and a fifth intermediate gear 415, respectively. The fourth intermediate gear 414 and the fifth intermediate gear 415 transmit the rotational force F from the third intermediate gear 413 to the first photosensitive member gear 3ay and the second photosensitive member gear 3am, respectively. In this embodiment, the first photosensitive member gear 3ay is formed on the same axis as the fourth intermediate gear 414, and the second photosensitive member gear 3am is formed on the same axis as the fifth intermediate gear 415.

[0038] The second gear train 420 includes a first intermediate gear 421 to a fifth intermediate gear 425, and transmits a rotational force F from the rotation shaft 401a of the rotation drive unit 401 to a third photoconductor gear 3ac and a fourth photoconductor gear 3ak, which rotate the two photoconductor drums 3c and 3k. The first intermediate gear 421 transmits the rotational force F from the rotation shaft 401a of the rotation drive unit 401 to a second intermediate gear 422. The second intermediate gear 422 transmits the rotational force F from the first intermediate gear 421 to a third intermediate gear 423. The third intermediate gear 423 transmits the rotational force F from the second intermediate gear 422 to a fourth intermediate gear 424 and a fifth intermediate gear 425, respectively. The fourth intermediate gear 424 and the fifth intermediate gear 425 transmit the rotational force F from the third intermediate gear 423 to the third photosensitive member gear 3ac and the fourth photosensitive member gear 3ak, respectively. In this embodiment, the third photosensitive member gear 3ac is formed on the same axis as the fourth intermediate gear 424, and the fourth photosensitive member gear 3ak is formed on the same axis as the fifth intermediate gear 425.

[0039] The third gear train 430 includes a first intermediate gear 431 to a third intermediate gear 433, and transmits the rotational force F from the second intermediate gear 422 of the second gear train 420 to a roller gear 721a that rotates the drive roller 721. The first intermediate gear 431 transmits the rotational force F from the second intermediate gear 422 of the second gear train 420 to the second intermediate gear 432. The second intermediate gear 432 transmits the rotational force F from the first intermediate gear 431 to the third intermediate gear 433. The third intermediate gear 433 transmits the rotational force F from the second intermediate gear 432 to the roller gear 721a that rotates the drive roller 721. In this embodiment, the roller gear 721a is formed on the same axis as the third intermediate gear 433.

[0040] As shown in FIGS. 5 to 8 , the fourth gear train 440 includes a first intermediate gear 441 to a fifth intermediate gear 445, and transmits the rotational force F from the rotation shaft 401a of the rotation drive unit 401 to a coupling gear 2ak, which transmits the rotational force F to the black developing device 2k. The first intermediate gear 441 transmits the rotational force F from the rotation shaft 401a of the rotation drive unit 401 to a second intermediate gear 442. The second intermediate gear 442 transmits the rotational force F from the first intermediate gear 441 to a third intermediate gear 443. The third intermediate gear 443 transmits the rotational force F from the second intermediate gear 442 to a fourth intermediate gear 444. The fourth intermediate gear 444 transmits the rotational force F from the third intermediate gear 443 to a fifth intermediate gear 445. The fifth intermediate gear 445 transmits the rotational force F from the fourth intermediate gear 444 to a coupling gear 2ak that transmits the rotational force F to the black developing device 2k. In this embodiment, the coupling gear 2ak and the fifth intermediate gear 445 are formed on the same axis.

[0041] The fifth gear train 450 includes a first intermediate gear 451, a clutch device 200, and second intermediate gears 452 to 455, and transmits a rotational force F from the first intermediate gear 441 of the fourth gear train 440 to coupling gears 2ac, 2am, and 2ay, which transmit the rotational force F to the cyan, magenta, and yellow developing devices 2c, 2m, and 2y, respectively, via the clutch device 200. The first intermediate gear 451 transmits the rotational force F from the first intermediate gear 441 of the fourth gear train 440 to an input gear portion 211 of an input gear 210 in the clutch device 200. An external tooth portion 232 (output gear portion) of an output gear 230 in the clutch device 200 transmits the rotational force F to the second intermediate gear 452 and the third intermediate gear 453, respectively. The second intermediate gear 452 and the third intermediate gear 453 transmit the rotational force to coupling gears 2ac and 2am, which transmit the rotational force to the cyan and magenta developing devices 2c and 2m, respectively. The fourth intermediate gear 454 transmits the rotational force F from the third intermediate gear 453 to a fifth intermediate gear 455. The fifth intermediate gear 455 transmits the rotational force F from the fourth intermediate gear 454 to a coupling gear 2ay, which transmits the rotational force F to the yellow developing device 2y. In this embodiment, the coupling gear 2ac is formed on the same axis as the second intermediate gear 452, the coupling gear 2am is formed on the same axis as the third intermediate gear 453, and the coupling gear 2ay is formed on the same axis as the fifth intermediate gear 455.

[0042] As will be described in detail later, in the drive device 400 described above, when the rotational drive unit 401 is rotated while the clutch device 200 is not operating (OFF state = non-operating state), the clutch device 200 does not transmit the rotational force F from the rotational drive unit 401 to the coupling gears 2ay, 2am, and 2ac, so the developing rollers 21y, 21m, and 21c of the developing devices 2y, 2m, and 2c, which develop with color toner, are stopped. Meanwhile, the belt 71, the photosensitive drums 3y, 3m, 3c, and 3k, and the developing roller 21k of the monochrome developing device 2k are rotated by the rotational force F of the rotational drive unit 401, so that the electrostatic latent image formed on the surface of the photosensitive drum 3k can be developed by the developing roller 21k to form a monochrome image. At this time, the developing rollers 21y, 21m, and 21c are stopped and do not rotate, which prevents the corresponding color toner from being worn down by their rotation. From this state, when the clutch device 200 is switched to an activated state (ON state = activated state) or when the rotation drive unit 401 is rotated with the clutch device 200 activated, the clutch device 200 transmits the rotational force F from the rotation drive unit 401 to the coupling gears 2ay, 2am, and 2ac, causing the developing rollers 21y, 21m, and 21c of the color toner developing devices 2y, 2m, and 2c to rotate. Here, the belt 71, the photosensitive drums 3y, 3m, 3c, and 3k, and the developing roller 21k of the monochrome developing device 2k are rotated by receiving the rotational force F from the rotation drive unit 401, so that the electrostatic latent images formed on the surfaces of the photosensitive drums 3y, 3m, 3c, and 3k can be developed by the developing rollers 21y, 21m, 21c, and 21k to form a color image.

[0043] (About this embodiment) Fig. 9 is an exploded perspective view showing an input gear 210, a carrier 220, and an output gear 230 in an example of a clutch device 200 according to the present embodiment. Fig. 10 is an exploded perspective view showing a state in which the output gear 230 is attached to the input gear 210 in Fig. 9.

[0044] (First embodiment) 11 and 12 are an exploded perspective view and a front view, respectively, showing a state in which some of the planetary gears 222, 222 are removed from the support shafts 223, 223 in the carrier 220 of the clutch device 200 according to the first embodiment. Also, Fig. 13 is a cross-sectional view showing a state in which the lubricant N held in the lubricant holding space SP by the cutout portion 223a is pushed out into the gap M21 between the carrier 220 and the planetary gears 222, 222 and the gap M22 between the output gear 230 and the planetary gears 222, 222.

[0045] The clutch device 200 of this embodiment is similar to the clutch device 200X shown in Figures 19 and 20, except that a cutout portion 223a is provided in the support shaft 223 and lubricant N is held in the lubricant holding space SP formed by the cutout portion 223a.

[0046] As shown in FIGS. 9 to 12, the clutch device 200 according to this embodiment includes an input gear 210, a carrier 220, and an output gear 230.

[0047] The input gear 210 has an input gear portion 211 and a sun gear portion 212. The input gear portion 211 receives a rotational force F from the rotation drive portion 401 and rotates about the first rotation axis α1. The sun gear portion 212 has a smaller outer diameter than the input gear portion 211 and rotates together with the input gear portion 211 about the first rotation axis α1. Specifically, the input gear 210 is provided with the input gear portion 211 integrally on the outer peripheral surface of a disk-shaped input gear main body 213 centered on the first rotation axis α1. The input gear 210 is also provided with the sun gear portion 212 integrally on the side of the input gear main body 213 facing the carrier 220 and the output gear 230. A circular through-hole 210a centered on the first rotation axis α1 is formed in the input gear main body 213 and the sun gear portion 212. Here, "hole" means a hole that penetrates through the input gear main body 213. The rotary shaft 201 is inserted through the through-hole portion 210a.

[0048] The carrier 220 is a rotating body that can rotate around a first rotation axis α1 and has a plurality of (three in this example) planetary gears 222, a plurality of support shafts 223, and one or a plurality of (six in this example) locked portions 221. The locked portions 221 are portions for stopping the rotation of the carrier 220 around the first rotation axis α1 and are wall portions that extend along both the rotation axis direction W of the carrier 220 and the radial direction E about the first rotation axis α1. More specifically, the carrier 220 has support shafts 223 that are erected integrally with the carrier 220, centered on the first rotation axis α1, on a side surface of a disc-shaped carrier body 224 that faces the input gear 210 and the output gear 230. In addition, a protrusion 225 having a plurality of mountain-shaped portions 225a that are high in the radial direction E is integrally formed on a side surface opposite to the support shafts 223. The downstream wall portions of the angled portions 225a-225a in the rotation direction D of the carrier 220 constitute the locked portion 221. A circular through-hole portion 220a centered on the first rotation axis α1 is formed in the carrier body 224 and the protruding portion 225. The rotation shaft 201 is inserted through the through-hole portion 220a.

[0049] The planetary gears 222-222 mesh with the sun gear portion 212. The plurality of support shafts 223-223 support the plurality of planetary gears 222-222 so that they can rotate freely around second rotation axes α2 that extend along the first rotation axis α1. More specifically, the planetary gears 222-222 are formed with circular through-holes 222a that are centered on the second rotation axis α2. The support shafts 223 are inserted into the through-holes 220a.

[0050] The output gear 230 is a gear that can rotate around the first rotation axis α1 and has an internal tooth portion (meshing gear portion) 231 and an external tooth portion 232 (output gear portion). The internal tooth portion 231 meshes with the plurality of planetary gears 222-222 on the inner side in the radial direction E centered on the first rotation axis α1. The external tooth portion 232 transmits a rotational force F on the outer side in the radial direction E. More specifically, the output gear 230 has the internal tooth portion 231 and the external tooth portion 232 integrally provided on a side surface of a disc-shaped output gear main body 233, on the carrier 220 side, centered on the first rotation axis α1. A circular through-hole 230a is formed in the output gear main body 233 and is centered on the first rotation axis α1. The sun gear portion 212 is inserted through the through-hole 230a.

[0051] 7 and 8, the locking device 300 has a locking portion 310 that is movable between a locking position where it is locked by the locked portion 221 of the carrier 220 and a non-locking position where it is not locked by the locked portion 221. In detail, the locking device 300 includes a solenoid body 301 that is an electromagnetic solenoid, a carrier arm (an example of the locking portion 310), and a biasing member 320 (a coil spring).

[0052] The solenoid body 301 is fixed to the body frame FL. The solenoid body 301 has a plunger 301a, and attracts the plunger 301a when turned on (when the solenoid body 301 is in an operating state and power is supplied to it = power supplied), and releases the attraction of the plunger 301a when turned off (when the solenoid body 301 is not in an operating state and power is not supplied to it = power not supplied). The carrier arm (310) is provided on the body frame FL so as to be swingable about a first swing axis β1 along the first rotation axis α1, and includes an arm portion 311 and an action portion 312. By swinging about the first swing axis β1, the arm portion 311 moves between an engagement position where it engages the locked portion 221 of the carrier 220 and an unlocked position where it is not engaged with the locked portion 221 of the carrier 220. The action portion 312 is provided on the plunger 301a so as to be swingable about a second swing axis β2 along the first rotation axis α1 on the opposite side of the arm portion 311 with the first swing axis β1 in between. The biasing member 320 biases the plunger 301a in the direction opposite to the suction side.

[0053] As a result, when the locking device 300 is turned on (power is supplied), it attracts the plunger 301a against the biasing force of the biasing member 320, causing the arm portion 311 to swing about the first swing axis β1 and lock the locked portion 221 of the carrier 220. In other words, it is possible to move the arm portion 311 of the carrier arm (310) to the locking position and stop the rotation of the carrier 220 about the first rotation axis α1. Furthermore, when the locking device 300 is turned off (power is not supplied), it releases the attraction of the plunger 301a, causing the arm portion 311 to swing about the first swing axis β1 due to the biasing force of the biasing member 320 and release the lock of the locked portion 221 of the carrier 220. In other words, it is possible to move the arm portion 311 of the carrier arm (310) to the unlocking position and release the stopped state of the rotation of the carrier 220 about the first rotation axis α1.

[0054] When the clutch device 200 is in an engaged state where the engaged portion 221 of the carrier 220 is engaged with the engaging portion 310 (carrier arm) of the locking device 300, i.e., when the locking portion 310 is in the engaged position, the clutch device 200 transmits the rotational force F of the input gear 210 to the output gear 230, and when it is in an unlocked state where the engaged state of the engaged portion 221 of the carrier 220 with the locking portion 310 of the locking device 300 is released, i.e., when the locking portion 310 is in the unlocked position, the clutch device 200 does not transmit the rotational force F of the input gear 210 to the output gear 230.

[0055] When the locking device 300 is off (when no power is supplied) and the rotational drive unit 401 is rotating, the rotational load that the coupling gears 2ac, 2am, and 2ay of the developing devices 2y, 2m, and 2c receive from the developing devices 2y, 2m, and 2c, respectively, acts on the output gear 230, so that the output gear 230 is stationary and the carrier 220 rotates by receiving the rotational force F from the rotational drive unit 401.

[0056] 11 to 13, the support shafts 223-223 are provided on their outer circumferential surfaces with one or more (two in this example) notches 223a, 223a for forming a lubricant holding space SP, which is a space for holding a lubricant N (see FIG. 13), between the support shafts 223-223 and the planetary gears 222-222. Note that the lubricant N is not shown in FIGS. 11 and 12.

[0057] Here, the lubricant N may be, for example, a semi-solid or solid lubricant, so-called grease, in which a thickener and / or additives are added to a base oil made from a mineral oil or synthetic oil.

[0058] According to this embodiment, the lubricant N is held in the lubricant holding space SP between the planetary gears 222 and the cutouts 223a provided on the outer circumferential surface of the support shafts 223, so that the sliding contact area between the support shafts 223 and the planetary gears 222 can be reduced only by the cutouts 223a, thereby suppressing wear of either or both of the planetary gears 222 and the support shafts 223. Moreover, the lubricant N can be stored in the lubricant holding space SP. As a result, by the planetary gears 222-222 rotating about the second rotation axis α2, the lubricant N in the lubricant retention space SP can be pushed out into the gaps M1 between the support shafts 223-223 and the planetary gears 222-222, the gaps M21 between the carrier 220 and the planetary gears 222-222, and the gaps M22 between the output gear 230 and the planetary gears 222-222. This allows the lubricant N to be distributed throughout the gaps M1, M21, and M22 for a long period of time.

[0059] Therefore, even if a load is applied to the planetary gears 222-222 and the support shafts 223-223, wear of either or both of the planetary gears 222-222 and the support shafts 223-223 can be suppressed, and deviation of the rotation center of the planetary gears 222-222 when the planetary gears 222-222 rotate about the second rotation axis α2 can be suppressed. Therefore, vibration of the planetary gears 222-222 can be effectively prevented. This is particularly effective when the planetary gears 222-222 and the support shafts 223-223 are made of resin. Resin materials that can be used for the planetary gears 222-222 and the support shafts 223-223 (in this example, the entire carrier 220) include, for example, polyacetal (POM), polyamide (PA), polycarbonate (PC), polyether ether ketone (PEEK), polyphenylene sulfide (PPS), liquid crystal polymer (LCP), and polyamide imide (PAI).

[0060] Furthermore, this is even more effective when the rotational force F is output toward the developing devices 2y, 2m, and 2c, which have a heavy load, because a corresponding load is applied to the planetary gears 222-222 and the support shafts 223-223. Furthermore, since the lubricant N can be stored in the lubricant retention space SP, even if wear progresses on either or both of the planetary gears 222-222 and the support shafts 223-223, a corresponding amount of lubricant N can be supplied from the lubricant retention space SP to each of the gaps M1, M21, and M22.

[0061] (Second embodiment) Figure 14 is an enlarged rear view showing an example of cutouts 223a, 223a provided in the support shafts 223-223 of the clutch device 200 according to the second embodiment, at a position away from the center of the second rotation axis α2 in an orthogonal direction L perpendicular to the radial direction E along the imaginary straight line γ (see also Figure 12) connecting the second rotation axis α2 and the first rotation axis α1.

[0062] Figure 15 is an enlarged rear view showing an example of the cutouts 223a, 223a provided in the support shafts 223-223 of the clutch device 200 according to the second embodiment, at a position spaced apart in the radial direction E from the center of the second rotation axis α2 along the imaginary straight line γ (see also Figure 12) connecting the second rotation axis α2 and the first rotation axis α1.

[0063] As shown in Figure 14, the cutout portion 223a is formed on the outer peripheral surface of at least one of the two sides of the support shaft 223 that are spaced apart from the center of the second rotation axis α2 in an orthogonal direction L that is perpendicular to the radial direction E along a line connecting the second rotation axis α2 and the first rotation axis α1.

[0064] Here, the distance da (see Figure 14) of the gap M1a (M1), which is the gap between the cutout portions 223a, 223a in the perpendicular direction L and the through hole portion 222a of the planetary gear 222, is larger than the distance db of the gap M1b (M1), which is the gap between the through hole portion 222a of the planetary gear 222 and the support shaft 223, in the radial direction E.

[0065] When the rotational force F from the input gear 210 is transmitted to the planetary gears 222, a load is applied to the planetary gears 222 in the radial direction E when the planetary gears 222 are rotationally driven.

[0066] 15, when the notch 223a is formed on the outer peripheral surface on at least one side (particularly both sides) of both sides in the radial direction E from the center of the second rotation axis α2, the distance db of the gap M1a between the through-hole 222a of the planetary gear 222, which is the gap in the radial direction E, becomes larger by the amount of the notch 223a than the distance db of the gap in the radial direction E in FIG. 14. Therefore, the rotation center of the planetary gears 222 is easily shifted due to the load in the radial direction E that acts when the rotational force F from the input gear 210 is transmitted to the planetary gears 222 to rotate them, and the planetary gears 222 to vibrate accordingly.

[0067] In this regard, in the present embodiment, the notch 223a is formed on at least one of both sides in the orthogonal direction L (both sides in this example) (see FIG. 14).

[0068] This makes it less likely that the rotation center of the planetary gears 222-222 will shift than when the cutout portion 223a is formed on at least one side (particularly both sides) of both sides in the radial direction E (see Figure 15), and therefore it is possible to suppress vibration of the planetary gears 222-222.

[0069] Here, when the notch 223a is formed on one side of the support shaft 223-223, an example of such a support shaft is a D-shaped shaft having an arc-shaped portion 223a1 formed in a circular arc shape in cross section and a linear portion 223a2 formed in a straight line shape in cross section. In this case, the linear portion 223a2 constitutes the notch 223a. When the notch 223a is formed on both sides of the support shaft 223-223, an example of such a support shaft is an I-shaped shaft having a pair of arc-shaped portions 223a1, 223a1 formed in an arc shape in two opposing positions in cross section and a pair of linear portions 223a2, 223a2 formed in a straight line shape in cross section. In this case, the pair of linear portions 223a2, 223a2 constitute the notch 223a, 223a.

[0070] Specifically, the rotating shaft 201 provided on the carrier 220 has arc-shaped portions 223a1 and 223a1 at meshing locations where force is generated by meshing of the planetary gears 222 and at opposing locations facing the meshing locations, respectively, and has linear portions 223a2 and 223a (notched portions 223a and 223a) at two locations excluding the meshing locations and the opposing locations. In this example, the linear portions 223a2 and 223a (notched portions 223a and 223a) are aligned along the radial direction E.

[0071] (Third embodiment) 16 and 17 are an exploded perspective view and a front view, respectively, showing a state in which some planetary gears 222, 222 are removed from support shafts 223, 223 in a carrier 220 of a clutch device 200 according to the third embodiment.

[0072] In this embodiment, the support shafts 223-223 are provided with lubricant holding portions 223b that communicate with the lubricant holding space SP and hold the lubricant N.

[0073] In this configuration, the lubricant N is held in the lubricant holding portion 223b, so that the lubricant N can be distributed over a long period of time in the gap M1 between the support shafts 223-223 and the planetary gears 222-222, the gap M21 between the carrier 220 and the planetary gears 222-222, and the gap M22 between the output gear 230 and the planetary gears 222-222.

[0074] More specifically, the lubricant holding portion 223b is a recess formed in the top portion 223c of the support shaft 223-223.

[0075] In this embodiment, the lubricant retaining portion 223b has a storage portion 223b1 that stores the lubricant N, and a communication portion 223b2 that communicates between the storage portion 223b1 and the lubricant retaining space SP.

[0076] In this configuration, the lubricant N is stored in the storage portion 223b1, and the lubricant N stored in the storage portion 223b1 can be supplied from the storage portion 223b1 to the lubricant holding space SP via the communication portion 223b2.

[0077] Specifically, the storage portion 223b1 is a deep hole with a bottom in the rotational axis direction W of the carrier 220, and the communication portion 223b2 is a groove that communicates between the hole (storage portion 223b1) and the lubricant retaining space SP. Here, "hole" means a "hole" with a bottom.

[0078] In this example, the hole portion (223b1) is a circular recess centered on the second rotation axis α2 in a cross-sectional view, and the groove portion (223b2) is a slit portion along the orthogonal direction L perpendicular to the radial direction E. Note that the storage portion 223b1 is not limited to a bottomed hole portion, but may be a through-hole portion that penetrates in the rotation axis direction W, and the communication portion 223b2 is not limited to a slit portion, but may be a through-hole portion that penetrates in the orthogonal direction L.

[0079] The present disclosure is not limited to the above-described embodiments, but can be implemented in various other forms. Therefore, the embodiments are merely examples in all respects and should not be interpreted as being limiting. The scope of the present disclosure is defined by the claims and is not bound by the text of the specification. Furthermore, all modifications and variations within the equivalent scope of the claims are within the scope of the present disclosure. [Explanation of symbols]

[0080] 100 Image forming device 101 Image forming apparatus main body 200 Clutch device 201 Rotation axis 210 Input gear 211 Input gear section 212 Sun Gear Section 213 Input gear body 21y developing roller 21m developing roller 21c Developing roller 21k developing roller 220 Career 221 Locked part 222 Planetary Gear 223 Spindle 223a Notch 223b Lubricant retaining section 223b1 Storage 223b2 Communication part 230 output gear 231 Internal teeth 232 External teeth 2c developing device 2m developing device 2y developing device 2k developing device 300 Locking device 310 Locking part 400 Drive Unit 401 Rotation drive unit D Rotation direction E Radial direction F rotational force L perpendicular direction M1 gap M1a gap M1b gap M21 gap M22 gap N Lubricant SP Lubricant retention space W Rotation axis direction X Width direction Y depth direction Z vertical direction da distance db distance α1 First rotation axis α2 Second rotation axis β1 First swing axis β2 Second swing axis γ Imaginary line

Claims

1. an input gear including an input gear portion that receives a rotational force from a rotation drive portion and rotates about a first rotation axis, and a sun gear portion that has an outer diameter smaller than that of the input gear portion and rotates about the first rotation axis together with the input gear portion; a carrier that is a rotating body rotatable around the first rotation axis, the carrier having a plurality of planetary gears that mesh with the sun gear portion, a plurality of support shafts that support the plurality of planetary gears so that they can rotate freely around second rotation axes that extend along the first rotation axis, and a locked portion that stops the rotation around the first rotation axis; an output gear that is rotatable about the first rotation axis and has an internal tooth portion that meshes with the plurality of planetary gears and an external tooth portion that transmits the rotational force; a locking device having a locking portion that is movable between a locking position where it is locked to the locked portion and a non-locking position where it is not locked to the locked portion; Equipped with a clutch device that transmits the rotational force to the output gear when the locking portion is in a locking position, and does not transmit the rotational force to the output gear when the locking portion is in a non-locked position, A clutch device according to claim 1, wherein a notch is provided on the outer peripheral surface of the support shaft to form a lubricant retention space between the support shaft and the planetary gear, the lubricant retention space being a space for retaining lubricant.

2. 2. The clutch device according to claim 1, the notch is formed on the outer peripheral surface of at least one of both sides spaced from the center of the second rotation axis in an orthogonal direction perpendicular to a radial direction along an imaginary line connecting the second rotation axis and the first rotation axis.

3. 3. The clutch device according to claim 2, The clutch device according to claim 1, wherein the notch is formed on the outer peripheral surface on both sides in the orthogonal direction.

4. 2. The clutch device according to claim 1, A clutch device according to claim 1, wherein the support shaft is provided with a lubricant retaining portion that communicates with the lubricant retaining space and retains the lubricant.

5. 5. The clutch device according to claim 4, The clutch device according to claim 1, wherein the lubricant retaining portion has a storage portion that stores the lubricant, and a communication portion that communicates the storage portion with the lubricant retaining space.

6. 2. The clutch device according to claim 1, 10. A clutch device according to claim 9, wherein the planetary gear and the support shaft are made of resin.

7. An image forming apparatus comprising the clutch device according to any one of claims 1 to 5.

Images