Drive device and image forming apparatus

Abstract

To provide a driving device that, when the driving device is divided into a plurality of units, can prevent displacement of the other unit with respect to a frame of one unit.SOLUTION: A driving device is included in a device having a conveying unit that conveys a recording material, and has: (i) a body frame; (ii) a first unit including a first rotating member, and a first frame that is fixed to the body frame and has a first support part supporting the first rotating member; (iii) a second unit including a second rotating member, and a second frame that is fixed to the body frame and has a second support part supporting the second rotating member; (iv) a transmission part that transmits a driving force received from the first rotating member to the second rotating member; and (v) a third frame that is fixed to the first frame and the second frame.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a drive device provided in an apparatus having a conveying section that conveys a recording material, and to an image forming apparatus provided with the drive device. [Background technology]

[0002] As an apparatus having a conveying section for conveying a recording material, a recording material conveying apparatus and an image forming apparatus for forming an image on the recording material are known. The conveying apparatus and the image forming apparatus are provided with a drive device for driving various components.

[0003] Patent Document 1 discloses a configuration in which the drive unit (drive device) of an image forming device is divided into multiple units, and the driving force of a motor is transmitted from one unit to another. Each unit has a frame that supports a gear via a shaft, and each frame is attached independently to a side plate of the device body. The gears of each unit directly mesh with each other, transmitting the driving force from one unit to another. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-131906 Summary of the Invention [Problem to be solved by the invention]

[0005] When a drive unit is divided into multiple units, gaps form between the frames of one unit and the other units, reducing the rigidity of the drive unit as a whole. As a result, for example, the frame of one unit may be more likely to displace relative to the frame of the other unit due to the load associated with drive transmission.

[0006] An object of the present invention is to provide a drive device that, when divided into a plurality of units, can suppress displacement of one unit relative to the frame of the other unit. [Means for solving the problem]

[0007] One of the inventions of the present application is as follows.

[0008] A drive device provided in an apparatus having a conveying unit that conveys a recording material, The body frame and a first unit including a first rotating member rotatable around a first axis and a first frame fixed to the main body frame and having a first support portion that supports the first rotating member; a second unit including a second rotating member rotatable around a second axis and a second frame fixed to the main body frame and having a second support portion that supports the second rotating member; a transmission unit configured to transmit a driving force received from the first rotating member to the second rotating member; a third frame fixed to the first frame and the second frame; A driving device comprising: [Effects of the Invention]

[0009] As described above, according to the present invention, it is possible to provide a drive device that can increase the rigidity of the drive device as a whole when the drive device is divided into a plurality of units. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is an overall view of an image forming apparatus. [Figure 2] FIG. 10 is a perspective view of a drive device according to a comparative example. [Figure 3] 1A is a perspective view of the drive device according to the first embodiment, and FIG. 1B is an exploded perspective view of the drive device according to the first embodiment. [Figure 4]FIG. 2 is a cross-sectional view of the drive device according to the first embodiment. [Figure 5] FIG. 10 is a perspective view of a drive device according to a second embodiment. [Figure 6] 10(a) and 10(b) are cross-sectional views of a drive device according to a second embodiment of the present invention; [Figure 7] FIG. 10 is a perspective view of a drive device according to a third embodiment. [Figure 8] FIG. 10 is a cross-sectional view of a drive device according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Preferred embodiments of the present invention will be described in detail below with reference to the drawings. However, the dimensions, materials, shapes, and relative positions of the components described in the following embodiments may be changed as appropriate depending on the configuration of the device to which the present invention is applied and various conditions. Therefore, unless otherwise specified, the scope of the present invention is not intended to be limited to these. [Example]

[0012] <Image forming device> The overall configuration of the image forming apparatus A and the image forming operation on the recording material P will be described with reference to Fig. 1. Fig. 1 is an overall view of the image forming apparatus A according to this embodiment.

[0013] In this embodiment, the image forming apparatus A is a laser beam printer that uses an electrophotographic process to form a monochrome image on a recording material P. The image forming apparatus A includes a conveying unit that feeds the recording material P and an image forming unit that forms a toner image on the recording material P.

[0014] The conveying section is provided with a feed tray 1 having a sheet stacking table on which recording materials P are stacked. The topmost recording material P is picked up by a feed roller 3, and the recording material P is conveyed by a conveying roller 4 and a driven roller 5 toward a registration roller 6 and an opposing roller 7. After skew of the recording material P is corrected by the registration roller 6, the recording material P is conveyed to the image forming section.

[0015] As part of the image forming unit, a process cartridge 8 that is removably mounted in the apparatus main body A1 of the image forming apparatus A is provided. The process cartridge 8 has a photosensitive drum 9 as an image carrier. The photosensitive drum 9 is a drum-shaped electrophotographic photosensitive member. The process cartridge 8 also has a charging roller 10 as a charging member that uniformly charges the surface of the photosensitive drum 9, and a developing sleeve (developing roller) 11 as a developer carrier that develops the electrostatic latent image formed on the surface of the photosensitive drum 9. The process cartridge 8 also has a cleaner 12 as a cleaning member that removes and collects residual toner remaining on the surface of the photosensitive drum 9.

[0016] The photosensitive drum 9 is driven to rotate at a predetermined peripheral speed in the clockwise direction in FIG. 1. The charging roller 10 uniformly charges the surface of the rotating photosensitive drum 9 with a predetermined polarity and potential. The apparatus main body A1 has a laser scanner unit 13 as an exposure means (exposure device). The laser scanner unit 13 emits laser light L corresponding to image information, exposing the surface of the rotating photosensitive drum 9. As a result, an electrostatic latent image corresponding to the image information is formed on the surface of the photosensitive drum 9. The developing sleeve 11 carries toner as a developer. The electrostatic latent image is developed into a toner image by the toner supplied from the developing sleeve 11.

[0017] The apparatus main body A1 has a transfer roller 2 as a transfer means (transfer member). The toner image is transferred from the photosensitive drum 9 to a recording material P by the transfer roller 2 in a nip formed by the photosensitive drum 9 and the transfer roller 2.

[0018] The apparatus main body A1 has a fixing device 14. The recording material P onto which the toner image has been transferred from the photosensitive drum 9 is conveyed to the fixing device 14. The fixing device 14 heats and pressurizes the toner image on the recording material P, fixing it to the recording material P. Thereafter, the recording material P is discharged onto a discharge tray 17 provided at the top of the apparatus main body A1 by discharge rollers 15, 16, etc.

[0019] In this embodiment, the feed roller 3, the transport roller 4, the driven roller 5, the registration roller 6, the opposing roller 7, the photosensitive drum 9, the transfer roller 2, the fixing device 14, and the discharge rollers 15 and 16 function as a transport unit that transports the recording material P. The process cartridge 8, the laser scanner unit 13, and the transfer roller 2 function as an image forming unit that forms an image on the recording material P. In other words, the image forming apparatus A in this embodiment is an apparatus that has a transport unit that transports the recording material P. In other words, the image forming apparatus A functions as a transport device that transports the recording material P.

[0020] In order to perform the image forming operation on the recording material P described above, the apparatus main body A1 of the image forming apparatus A is provided with a motor M as a drive source and a control section C that controls the motor M.

[0021] <Driving device of comparative example> The configuration of a drive device D0 according to a comparative example will be described using Fig. 2. Fig. 2 is a perspective view of the drive device D0 according to the comparative example. The device main body A1 of the image forming device A has a main body frame 99. As shown in Fig. 2, the drive device D0 according to the comparative example has the main body frame 99, an input drive unit 100, and an output drive unit 110.

[0022] The drive unit is divided into two drive units, an input drive unit 100 and an output drive unit 110, and fixed to a main body frame 99. The driving force of a motor M is input to the input drive unit 100 via a motor pinion 101. The driving force input to the input drive unit 100 is transmitted to the output drive unit 110 via interface gears 105 and 115.

[0023] 2, the input drive unit 100 has a drive frame 104, an interface gear 105, and a plurality of idler gears 102 for transmitting the drive force received from the motor pinion 101 to the interface gear 105. The drive frame 104 is formed from a metal plate. The drive frame 104 has a metal support shaft 103 as a support portion for supporting the idler gear 102 and the interface gear 105.

[0024] The output drive unit 110 has a drive frame 114, an interface gear 115, and multiple idler gears 112. The drive frame 114 is formed from sheet metal (metal plate). The drive frame 114 has a metal support shaft 113 as a support portion that supports the interface gear 115 and the idler gear 112. The interface gear 115 meshes with the interface gear 105 of the input drive unit 100, and drive is transmitted from the interface gear 105. In addition, an output portion (not shown) that drives the above-mentioned conveyance portion and process cartridge 8 is connected to the downstream side of the idler gear 112.

[0025] To prevent deformation of the drive frames 104, 114 when they receive a drive reaction force associated with drive transmission, it is preferable that the drive frames 104, 114 have high rigidity. The drive frames 104, 114 are formed by bending a metal plate, and fixing portions for fixing to the main body frame 99 are provided on the side walls of the drive frames 104, 114. By integrating the drive frames 104, 114 and the main body frame 99 at these fixing portions, the rigidity of the drive frames 104, 114 is increased.

[0026] However, in a configuration in which the interface gears 105, 115 directly mesh with each other, openings 104a, 114a are required in the drive frames 104, 114 to expose the interface gears 105, 115. As a result, the rigidity of the drive frames 104, 114 is reduced compared to a configuration in which side walls are disposed at positions corresponding to the openings 104a, 114a. Furthermore, it is not possible to dispose fixing parts to the main frame 99 at positions corresponding to the openings 104a, 114a. Therefore, it is difficult to integrate the drive frames 104, 114 with the main frame 99 and increase the rigidity of the drive frames 104, 114 at the positions of the openings 104a, 114a.

[0027] In the comparative example, the drive device D0 has a configuration in which the interface gears 105, 115 are always in mesh, but even if either of the interface gears 105, 115 is a pendulum gear or the like, the openings 104a, 114a are still required. Therefore, even if either of the interface gears 105, 115 is a pendulum gear or the like, the same problem arises regarding the rigidity of the drive frames 104, 114.

[0028] (Description of the configuration of the drive coupling portion of this embodiment) Next, the driving device D1 according to this embodiment will be described with reference to Figures 3(a), 3(b), and 4. The image forming apparatus A includes the driving device D1.

[0029] Fig. 3(a) is a perspective view of the driving device D1 according to this embodiment. Fig. 3(b) is an exploded perspective view of the driving device D1 according to this embodiment. Fig. 4 is a cross-sectional view of the driving device D1 according to this embodiment. Fig. 4 is a cross-sectional view taken along line AA in Fig. 3(a).

[0030] 3(a) and 3(b), the drive device D1 according to this embodiment has a main body frame 99, a first drive unit (first unit) 200, a second drive unit (second unit) 210, and a third drive unit (third unit) 220. The first drive unit 200 and the second drive unit 210 are each fixed to the main body frame 99 with screws SC, and the third drive unit 220 is fixed to the outside of the first frame (first drive frame) 201 and the second frame (second drive frame) 211 with screws SC.

[0031] As shown in Figures 3(a) and 3(b), the first drive unit 200 has a first frame 201 formed from sheet metal (metal plate), a pinion gear 202, an idler gear 203, an input side gear (first rotating member) 205, and a square shaft 206 press-fitted into the input side gear 205.

[0032] A driving force is transmitted from a motor M to the pinion gear 202. The driving force is transmitted from the pinion gear 202 to an input gear 205 via an idler gear 203. The input gear 205 is rotatable around a first axis A1.

[0033] The first frame 201 is fixed to the main body frame 99 and has a first support wall 201b extending in a direction intersecting (orthogonal in this embodiment) the first axis A1, and first side walls 201c1, 201c2, 201c3, and 201c4 extending in the direction of the first axis A1. The first support wall 201b is parallel to the main body frame 99, and a metal support shaft 204 serving as a support portion for the idler gear 203 is crimped to the first support wall 201b. Furthermore, a hole 201a serving as a first support portion for supporting the input gear 205 is formed in the first support wall 201b. The pinion gear 202, the idler gear 203, and the input gear 205 are located between the first support wall 201b and the main body frame 99 in the direction of the first axis A1.

[0034] The first side walls 201c1, 201c2, 201c3, and 201c4 extend in a direction intersecting (orthogonal in this embodiment) the direction in which the first support wall 201b extends. 201c1 faces 201c2, and 201c3 faces 201c4. 201c3 and 201c4 are provided with first fixed portions that are fixed to the main body frame 99 with screws SC. The first fixed portions extend in a direction intersecting (orthogonal in this embodiment) 201c3 and 201c4. The extension direction of 201c1 and 201c2 intersects with the extension direction of 201c3 and 201c4.

[0035] The space formed between the first support wall 201b and the main body frame 99 is referred to as the first space. The first side walls 201c1, 201c2, 201c3, and 201c4 are arranged to surround the first space. The pinion gear 202, the idler gear 203, and the input side gear 205 are housed in the first space. In this embodiment, the entire input side gear 205 is housed in the first space, but a portion of the input side gear 205 may be located outside the first space. In other words, the first frame 201 covers the input side gear 205 so that at least a portion of the input side gear 205 is housed in the first space. When viewed along the first axis A1, the first support wall 201b and the input side gear 205 at least partially overlap.

[0036] The first frame 201 can also be said to have a box shape formed by the first side walls 201c1, 201c2, 201c3, and 201c4 and the first support wall 201b. The pinion gear 202, the idler gear 203, and the input gear 205 are housed in a recess defined by the first side walls 201c1, 201c2, 201c3, and 201c4 and the first support wall 201b. The portion of the first frame 201 facing this recess or the first space can be referred to as the inside of the first frame 201. The portion of the first frame 201 opposite the recess or the first space can be referred to as the outside of the first frame 201.

[0037] Furthermore, the first drive unit 200 may receive the driving force from the motor M from a member outside the first space.

[0038] 3(a) and 3(b), the second drive unit 210 has a second frame 211 formed from sheet metal (metal plate), an output gear (second rotating member) 212, and an idler gear 213. An output portion (not shown) that drives a driven portion (conveyance portion or process cartridge 8) is connected to the downstream side of the idler gear 213. The driven portion can be said to be a transmitted portion to which drive is transmitted from the idler gear 213.

[0039] The driving force of the motor M is transmitted to the output gear 212 via the input gear 205 and idler gears 222 and 223, which will be described later. The driving force is transmitted from the output gear 212 to the output section via the idler gear 213. The output gear 212 is rotatable around the second axis A2. In this embodiment, the first axis A1 and the second axis A2 are parallel to each other.

[0040] The second frame 211 is fixed to the main frame 99 and has a second support wall 211b extending in a direction intersecting (orthogonal in this embodiment) the second axis A2, and second side walls 211c1, 211c2, 211c3, and 211c4 extending in the direction of the second axis A2. The second frame 211 is fixed at a position separated from the first frame 201, and a gap is formed between the second frame 211 and the first frame 201. The second support wall 211b is parallel to the main frame 99, and a metal support shaft 214 serving as a support portion for the idler gear 213 is crimped to the second support wall 211b. Furthermore, a hole 211a serving as a second support portion for supporting the output gear 212 is formed in the second support wall 211b. In the direction of the second axis A2, the output gear 212 and the idler gear 213 are located between the second support wall 211b and the main frame 99.

[0041] The second side walls 211c1, 211c2, 211c3, and 211c4 extend in a direction intersecting (orthogonal in this embodiment) the direction in which the second support wall 211b extends. 211c1 faces 211c2, and 211c3 faces 211c4. 211c3 and 211c4 are provided with second fixed portions that are fixed to the main body frame 99 with screws SC. The second fixed portions extend in a direction intersecting (orthogonal in this embodiment) 211c3 and 211c4. The extension direction of 211c1 and 211c2 intersects the extension direction of 211c3 and 211c4.

[0042] The space formed between the second support wall 211b and the main body frame 99 is referred to as the second space. The second side walls 211c1, 211c2, 211c3, and 211c4 are arranged to surround the second space. The output gear 212 and the idler gear 213 are housed in the second space. In this embodiment, the entire output gear 212 is housed in the second space, but a portion of the output gear 212 may be located outside the second space. In other words, the second frame 211 covers the output gear 212 so that at least a portion of the output gear 212 is housed in the second space. When viewed along the second axis A2, the second support wall 211b and the output gear 212 at least partially overlap.

[0043] The second frame 211 can also be said to have a box shape formed by the second side walls 211c1, 211c2, 211c3, and 211c4 and the second support wall 211b. The output gear 212 and the idler gear 213 are housed in a recess defined by the second side walls 211c1, 211c2, 211c3, and 211c4 and the second support wall 211b. The portion of the second frame 211 facing this recess or the second space can be referred to as the inside of the second frame 211. The portion of the second frame 211 opposite the recess or the second space can be referred to as the outside of the second frame 211.

[0044] The third drive unit 220 has a third frame (third drive frame) 221 formed from sheet metal (metal plate), an idler gear (first transmission part, first transmission gear) 222, and an idler gear (second transmission part, second transmission gear) 223. The idler gear 222 is driven by the input side gear 205, and the idler gear 223 is driven by the idler gear 222 to drive the output side gear 212. The idler gear 222 and the idler gear 223 function as transmission parts configured to transmit the driving force received from the input side gear 205 to the output side gear 212.

[0045] The idler gear 222 has a hole that engages with the square shaft 206. The idler gear 222 is disposed coaxially with the input gear 205 of the first drive unit 200 and is rotatable about the first axis A1. The square shaft 206 causes the input gear 205 and the idler gear 222 to rotate together. The input gear 205 is adjacent to the idler gear 222. In other words, of the gears of the first drive unit 200, the input gear 205 is the gear closest to the idler gear 222.

[0046] The idler gear 223 is disposed coaxially with the output gear 212 of the second drive unit 210 and is rotatable around the second axis A2. The rotary shaft tip 212a of the output gear 212 has a D-cut shape, and the rotary shaft tip 212a is fitted into a D-cut hole opened in the idler gear 223. As a result, the idler gear 223 and the output gear 212 rotate integrally.

[0047] In this embodiment, the idler gear 223 is directly meshed with the idler gear 222, but an intermediate transmission member such as a belt or gear may be interposed between the idler gear 223 and the idler gear 222.

[0048] The third frame 221 is fixed to the first support wall 201b of the first frame 201 and the second support wall 211b of the second frame 211. The third frame 221 has a third support wall 221b extending in a direction intersecting (orthogonal to) the first axis A1, and third side walls 221c1, 221c2, 221c3, and 221c4 extending in the direction of the first axis A1. The third support wall 221b is parallel to the main body frame 99, and is provided with a hole 221a1 serving as a support portion (third support portion) for the idler gear 222 and a hole 221a2 serving as a support portion (third support portion) for the idler gear 223.

[0049] The third side walls 221c1, 221c2, 221c3, and 221c4 extend in a direction intersecting (orthogonal in this embodiment) the direction in which the third support wall 221b extends. 221c1 faces 221c2, and 221c3 faces 221c4. 221c3 and 221c4 are provided with third fixed portions that are fixed to the first frame 201 and the second frame 211 with screws SC. The third fixed portions extend in a direction intersecting (orthogonal in this embodiment) 221c3 and 221c4. The extension direction of 221c1 and 221c2 intersects the extension direction of 221c3 and 221c4.

[0050] The spaces formed between the third support wall 221b and the first frame 201 and between the third support wall 221b and the second frame 211 are referred to as third spaces. The third side walls 221c1, 221c2, 221c3, and 221c4 are arranged to surround the third space. The idler gears 222 and 223 are housed in the third space. In this embodiment, the idler gears 222 and 223 are entirely housed in the third space, but portions of the idler gears 222 and 223 may be outside the third space. In other words, the third frame 221 covers the idler gears 222 and 223 so that at least portions of the idler gears 222 and 223 are housed in the third space. When viewed along the first axis A1, the third support wall 221b and the idler gears 222 and 223 at least partially overlap each other.

[0051] The third frame 221 can also be said to have a box shape formed by the third side walls 221c1, 221c2, 221c3, and 221c4 and the third support wall 221b. Idler gears 222 and 223 are housed in a recess defined by the third side walls 221c1, 221c2, 221c3, and 221c4 and the third support wall 221b. The portion of the third frame 221 facing this recess or the third space can be referred to as the inside of the third frame 221. The portion of the third frame 221 opposite the recess or the third space can be referred to as the outside of the third frame 221.

[0052] In this embodiment, the idler gear 222 as part of the transmission unit is located on the opposite side of the first space from the first frame 201 in the direction of the first axis A1. The idler gear 223 as part of the transmission unit is located on the opposite side of the second space from the second frame 211 in the direction of the second axis A2. Furthermore, the idler gear 222 as part of the transmission unit is disposed between the first support wall 201b and the third support wall 221b in the direction of the first axis A1. The idler gear 224 as part of the transmission unit is disposed between the second support wall 211b and the third support wall 221b in the direction of the second axis A2 that is parallel to the direction of the first axis A1.

[0053] As described above, in this embodiment, the third drive unit 220 is disposed between the first drive unit 200 and the second drive unit 210, and drive is transmitted from the first drive unit 200 to the second drive unit 210 via the third drive unit 220.

[0054] Next, the configurations of the first drive unit 200, the second drive unit 210, and the third drive unit 220 will be described in more detail with reference to FIG.

[0055] The input gear 205 of the first drive unit 200 is rotatably supported by a hole 201a in the first frame 201 and a hole 99a in the main body frame 99. The holes 201a and 99a are formed by burring. A hole is formed inside the input gear 205, into which a square shaft 206 is press-fitted. The square shaft 206 is inserted into a hole in the idler gear 222. The square shaft 206 is a connecting member that connects the input gear 205 and the idler gear 222 so that the input gear 205 and the idler gear 222 rotate integrally. The driving force transmitted to the input gear 205 is transmitted to the third drive unit 220 by the square shaft 206.

[0056] The output gear 212 of the second drive unit 210 is rotatably supported by a hole 211a in the second frame 211 and a hole 99b in the main frame 99. The holes 211a and 99b are formed by burring. The tip 212a of the rotary shaft of the output gear 212 has a D-cut shape and is inserted into a D-cut hole in the idler gear 223 of the third drive unit 220.

[0057] That is, the drive device D1 of this embodiment has a two-layer structure in which the third drive unit 220, which serves as a drive coupling portion, is positioned offset in the direction of the first axis A1 or the second axis A2 relative to the first drive unit 200 and the second drive unit 210. Drive transmission from the first drive unit 200 to the third drive unit 220 and from the third drive unit 220 to the second drive unit 210 is performed in the direction of the first axis A1 and the direction of the second axis A2. Therefore, it is not necessary to provide openings 104a, 114a as shown in FIG. 2 in the first drive unit 200 and the second drive unit 210. This allows the first frame 201 and the second frame 211 to have a box shape, thereby increasing the rigidity of the first frame 201 and the second frame 211.

[0058] Furthermore, by fastening the third frame 221 of the third drive unit 220 to the first frame 201 and the second frame 211 with screws SC, the three drive units are integrated, increasing the overall rigidity. Therefore, displacement of the second frame 211 relative to the first frame 201 is suppressed, and the distance between the first axis A1 and the second axis A2 is kept constant.

[0059] 4, the first side wall (wall portion) 201c1 of the first frame 201 is disposed between the input side gear 205 and the output side gear 212. More specifically, the first side wall 201c1 is disposed between the input side gear 205 and the output side gear 212 in the direction perpendicular to the first axis A1, and faces the gear surface of the input side gear 205. It can also be said that the first side wall 201c1 is disposed between the first space and the second space.

[0060] The second side wall (wall portion) 211c1 of the second frame 211 is disposed between the input side gear 205 and the output side gear 212. More specifically, the second side wall 211c1 is disposed between the input side gear 205 and the output side gear 212 in the direction perpendicular to the second axis A2, and faces the gear surface of the output side gear 212. It can also be said that the second side wall 211c1 is disposed between the first space and the second space.

[0061] Furthermore, it is preferable that at least one of the first side walls 201c1, 201c2, 201c3, and 201c4 engage with the main body frame 99. In this embodiment, the tips of the first side walls 201c1, 201c2, and 201c3 form engaging portions that engage with the main body frame 99. The first side wall 201c4 may also have an engaging portion. The engaging portions of the first side walls 201c1, 201c2, and 201c3 also serve to position the first frame 201 relative to the main body frame 99.

[0062] Similarly, it is preferable that at least one of the second side walls 211c1, 211c2, 211c3, and 211c4 engage with the main body frame 99. In this embodiment, the tips of the second side walls 211c1, 211c2, and 211c3 form engaging portions that engage with the main body frame 99. The second side wall 211c4 may also have an engaging portion. The engaging portions of the second side walls 211c1, 211c2, and 211c3 also serve to position the second frame 211 relative to the main body frame 99. The second side wall 211c1, together with the first side wall 201c1, engages with one hole (engaged portion) of the main body frame 99.

[0063] It is preferable that at least one of the third side walls 221c1, 221c2, 221c3, and 221c4 engage with the first frame 201 or the second frame 211. In this embodiment, the tips of the third side walls 221c1 and 221c4 are engaging portions that engage with the second support wall 211b of the second frame 211. The tip of the third side wall 221c3 is an engaging portion that engages with the first support wall 201b of the first frame 201. Note that the third side wall 221c2 may also have an engaging portion. The engaging portion of the third side wall 221c3 also serves to position the third frame 221 relative to the first frame 201. The engaging portions of the third side walls 221c1 and 221c4 also serve to position the third frame 221 relative to the second frame 211.

[0064] Furthermore, the bent portion for forming the third side wall portion 221c1 of the third frame 221 and the third side wall portion 221c1 extend so as to overlap the first frame 201, the second frame 211, and the gap between the first frame 201 and the second frame 211. As a result, the first frame 201, the second frame 211, and the third frame 221 are firmly connected, and displacement of each frame relative to the other frames is suppressed.

[0065] Either the first side wall 201c1 or the second side wall 211c1 may be omitted. In other words, it is sufficient that at least one of the first frame 201 and the second frame 211 has a wall portion disposed between the input side gear 205 and the output side gear 212.

[0066] When the input side gear 205 and the output side gear 212 directly mesh with each other, it is not possible to arrange the first side wall 201c1 or the second side wall 211c1 at the position where the input side gear 205 and the output side gear 212 mesh with each other. However, according to the configuration of this embodiment, it is not necessary to directly mesh the input side gear 205 and the output side gear 212. Therefore, the degree of freedom in design for arranging the first side wall 201c1 and the second side wall 211c1 is improved.

[0067] Furthermore, by connecting the first frame 201 and the second frame 211 with the third frame 221, it is possible to improve the rigidity of the first frame 201, the second frame 211, and the third frame 221. Furthermore, by fixing the third frame 221 to the first support wall 201b and the second support wall 211b, it is possible to prevent the first support wall 201b and the second support wall 211b from shifting from one another.

[0068] Furthermore, since each of the first frame 201, the second frame 211, and the third frame 221 has a box shape, the rigidity of each frame is also increased. [Example]

[0069] Next, a driving device D2 of an image forming apparatus A according to a second embodiment will be described with reference to Figures 5 and 6. The same parts as those in the first embodiment will be given the same reference numerals and the description thereof will be omitted.

[0070] Fig. 5 is a perspective view of the drive device D2 according to this embodiment. The upper right portion of Fig. 5 is an enlarged view of a portion of the drive device D2. The drive device D2 according to this embodiment differs from the drive device D1 according to the first embodiment in the configurations of the second drive unit and the third drive unit.

[0071] As shown in Figure 5, the drive device D2 has a first drive unit 200 and a second drive unit 310 each fixed to the main frame 99 with screws SC, and a third drive unit 320 fixed to the outside of the first frame 201 and the second frame 311 with screws SC.

[0072] The first drive unit 200 has the same configuration as that shown in the first embodiment, and therefore a description thereof will be omitted.

[0073] 5, the second drive unit 310 has a second frame (second drive frame) 311 formed from sheet metal (metal plate), an output gear (second rotating member) 312, and an idler gear 313. An output portion (not shown) that drives a driven portion (a conveying portion or a process cartridge 8) is connected to the downstream side of the idler gear 313.

[0074] The driving force of the motor M is transmitted to the output gear 312 via the input gear 205 and idler gears 322, 323, and 324, which will be described later. The driving force is transmitted from the output gear 312 to the output section via the idler gear 313. The output gear 312 is rotatable around the second axis A2. In this embodiment, the first axis A1 and the second axis A2 are parallel to each other.

[0075] The second frame 311 is fixed to the main frame 99, and has second support walls 311b1 and 311b2 extending in a direction intersecting (orthogonal in this embodiment) the direction of the second axis A2, and second side walls 311c1, 311c2, 311c3, and 311c4 extending in the direction of the second axis A2. The second frame 311 is fixed at a position separated from the first frame 201, and a gap is formed between the second frame 311 and the first frame 201. The second support walls 311b1 and 311b2 are parallel to the main frame 99, and a metal support shaft 315 serving as a support portion for the idler gear 313 and a resin support shaft 314 serving as a support portion for the output side gear 312 are fixed to the second support wall 311b2. The output gear 312 and the idler gear 313 are located between the second support wall 311b2 and the main body frame 99 in the direction of the second axis A2.

[0076] The second side walls 311c1, 311c2, 311c3, and 311c4 extend in a direction intersecting (orthogonal in this embodiment) the direction in which the second support walls 311b1 and 311b2 extend. 311c1 faces 311c2, and 311c3 faces 311c4. 311c3 and 311c4 are provided with second fixed portions that are fixed to the main body frame 99 with screws SC. The second fixed portions extend in a direction intersecting (orthogonal in this embodiment) 311c3 and 311c4. The extension direction of 311c1 and 311c2 intersects the extension direction of 311c3 and 311c4.

[0077] The space formed between the second support walls 311b1, 311b2 and the main body frame 99 is referred to as the second space. The second side walls 311c1, 311c2, 311c3, and 311c4 are arranged to surround the second space. The output gear 312 and the idler gear 313 are housed in the second space. In this embodiment, a gear portion, which is a part of the output gear 312, is exposed to the outside of the second space through an opening 311d provided in the second frame 311. In other words, the second frame 311 covers the output gear 312 so that at least a portion of the output gear 312 is housed in the second space. When viewed along the second axis A2, the second support wall 311b2 and the output gear 312 at least partially overlap each other.

[0078] The second frame 311 can also be said to have a box shape formed by the second side walls 311c1, 311c2, 311c3, and 311c4 and the second support walls 311b1 and 311b2. The output gear 312 and the idler gear 313 are housed in a recess defined by the second side walls 311c1, 311c2, 311c3, and 311c4 and the second support walls 311b1 and 311b2. The portion of the second frame 311 facing the recess or the second space can be referred to as the inside of the second frame 311. The portion of the second frame 311 opposite the recess or the second space can be referred to as the outside of the second frame 311.

[0079] The third drive unit 320 has a third frame (third drive frame) 321 formed from sheet metal (metal plate), an idler gear (first transmission portion, first transmission gear) 322, an idler gear 323 (intermediate portion, intermediate gear), and an idler gear (second transmission portion, second transmission gear) 324. The idler gear 322 is driven by the input side gear 205, and the idler gear 324 is driven by the idler gear 322 via the idler gear 323, and drives the output side gear 312. The idler gear 322, the idler gear 323, and the idler gear 324 function as transmission portions configured to transmit the driving force received from the input side gear 205 to the output side gear 312.

[0080] The idler gear 322 has a hole that engages with the square shaft 206. The idler gear 322 is disposed coaxially with the input gear 205 of the first drive unit 200 and is rotatable about the first axis A1. The square shaft 206 causes the input gear 205 and the idler gear 322 to rotate together. The input gear 205 is adjacent to the idler gear 322. In other words, of the gears of the first drive unit 200, the input gear 205 is the gear closest to the idler gear 322.

[0081] The idler gear 324 is rotatable around a third axis A3. The third axis A3 is located at a position spaced apart from the second axis A2. In this embodiment, the third axis A3 and the second axis A2 are parallel to each other. The output gear 312 directly meshes with the idler gear 324.

[0082] In this embodiment, the drive is transmitted from the idler gear 322 to the idler gear 324 via the idler gear 323. However, instead of the idler gear 323, the drive may be transmitted from the idler gear 322 to the idler gear 324 via an intermediate transmission member other than a gear, such as a belt.

[0083] The third frame 321 is fixed to the first support wall 201b of the first frame 201 and the second support wall 311b2 of the second frame 311. The third frame 321 has a third support wall 321b extending in a direction intersecting (orthogonal to) the first axis A1, and third side walls 321c1, 321c2, 321c3, 321c4, and 321c5 extending in the direction of the first axis A1. The third support wall 321b is parallel to the main body frame 99, and is provided with a hole 321a1 serving as a support portion (third support portion) for the idler gear 322, a hole 321a2 serving as a support portion (third support portion) for the idler gear 323, and a hole 321a3 serving as a support portion for the idler gear 324.

[0084] The third side walls 321c1, 321c2, 321c3, 321c4, and 321c5 extend in a direction intersecting (orthogonal in this embodiment) the direction in which the third support wall 321b extends. 321c1 faces 321c2, and 321c3 faces 321c4. 321c3 and 321c5 are provided with third fixed portions that are fixed to the first frame 201 and the second frame 311 with screws SC. The third fixed portions extend in a direction intersecting (orthogonal in this embodiment) 321c3 and 321c5. The extension direction of 321c1, 321c2, and 321c5 intersects the extension direction of 321c3 and 321c4.

[0085] The spaces formed between the third support wall 321b and the first frame 201 and between the third support wall 321b and the second frame 311 are referred to as third spaces. The third side walls 321c1, 321c2, 321c3, 321c4, and 321c5 are arranged to surround the third space. The idler gears 322, 323, and 324 are housed in the third space. In this embodiment, the idler gears 322, 323, and 324 are entirely housed in the third space, but portions of the idler gears 322, 323, and 324 may be outside the third space. In other words, the third frame 321 covers the idler gears 322, 323, and 324 so that at least portions of the idler gears 322, 323, and 324 are housed in the third space. When viewed along the first axis A1, the third support wall 321b and the idler gear 322, the idler gear 323, and the idler gear 324 at least partially overlap with each other.

[0086] Third frame 321 can also be said to have a box shape formed by third side walls 321c1, 321c2, 321c3, 321c4, and 321c5 and third support wall 321b. Idler gears 322, 323, and 324 are housed in a recess defined by third side walls 321c1, 321c2, 321c3, 321c4, and 321c4 and third support wall 321b. The portion of third frame 321 facing this recess or the third space can be referred to as the inside of third frame 321. The portion of third frame 321 opposite this recess or the third space can be referred to as the outside of third frame 321.

[0087] In this embodiment, the idler gear 322 as part of the transmission unit is located on the opposite side of the first space from the first frame 201 in the direction of the first axis A1. The idler gear 324 as part of the transmission unit is located on the opposite side of the second space from the second frame 311 in the direction of the second axis A2. Furthermore, the idler gear 322 as part of the transmission unit is disposed between the first support wall 201b and the third support wall 321b in the direction of the second axis A2 that is parallel to the direction of the first axis A1. The idler gear 324 as part of the transmission unit is disposed between the second support wall 311b and the third support wall 321b in the direction of the second axis A2 that is parallel to the direction of the first axis A1.

[0088] As described above, in this embodiment as well, the third drive unit 320 is disposed between the first drive unit 200 and the second drive unit 310, and the drive is transmitted from the first drive unit 200 to the second drive unit 310 via the third drive unit 320. Therefore, the same effects as in the first embodiment can be obtained.

[0089] Next, the detailed configurations of the first drive unit 200, the second drive unit 310, and the third drive unit 320 will be described using Figures 6(a) and 6(b), and the drive transmission from the first drive unit 200 to the second drive unit 310 will be described. Figures 6(a) and 6(b) are cross-sectional views of the drive device D2 according to this embodiment. Figure 6(a) is a cross-sectional view taken along line BB in Figure 5, and Figure 6(b) is a cross-sectional view taken along line CC in Figure 5.

[0090] 6(a), the square shaft 206 is inserted into a hole in the idler gear 322. The square shaft 206 is a connecting member that connects the input gear 205 and the idler gear 322 so that the input gear 205 and the idler gear 322 rotate integrally. The driving force transmitted to the input gear 205 is transmitted to the third drive unit 320 by the square shaft 206.

[0091] 6(b), the output side gear 312 of the second drive unit 310 meshes with the idler gear 324 of the third drive unit 320. The position where the output side gear 312 meshes with the idler gear 324 and the position where the output side gear 312 meshes with the idler gear 313 are shifted in the direction of the second axis A2.

[0092] The driving device D2 of this embodiment has a two-layer structure in which the third driving unit 320, which is the driving connection portion, is disposed at a position offset in the direction of the first axis A1 or the second axis A2 relative to the first driving unit 200 and the second driving unit 310. Therefore, the first frame 201 and the second frame 311 can have a box shape, and the rigidity of the first frame 201 and the second frame 311 can be increased.

[0093] Furthermore, by fastening the third frame 321 of the third drive unit 320 to the first frame 201 and the second frame 311 with screws SC, the three drive units are integrated, increasing the overall rigidity. This suppresses displacement of the second frame 311 relative to the first frame 201.

[0094] 6(a), the first side wall (wall portion) 201c1 of the first frame 201 is disposed between the input side gear 205 and the output side gear 312. More specifically, the first side wall 201c1 is disposed between the input side gear 205 and the output side gear 312 in the direction perpendicular to the first axis A1, and faces the gear surface of the input side gear 205. It can also be said that the first side wall 201c1 is disposed between the first space and the second space.

[0095] The second side wall (wall portion) 311c1 of the second frame 311 is disposed between the input side gear 205 and the output side gear 312. More specifically, the second side wall 311c1 is disposed between the input side gear 205 and the output side gear 312 in the direction perpendicular to the second line A2, and faces the gear surface of the output side gear 312. It can also be said that the second side wall 311c1 is disposed between the first space and the second space.

[0096] Furthermore, similarly to the first embodiment, it is preferable that at least one of the second side walls 311c1, 311c2, 311c3, and 311c4 engage with the main body frame 99. The second side wall 311c1 is engaged with the same hole (engaged portion) as the first side wall 201c1.

[0097] Similarly, it is preferable that at least one of the third side walls 321c1, 321c2, 321c3, 321c4, 321c5 engage with the first frame 201 or the second frame 311.

[0098] Furthermore, third side wall 321c1 of third frame 321 and the bent portion for forming third side wall portion 321c1 extend so as to overlap first frame 201, second frame 311, and the gap between first frame 201 and second frame 311. As a result, first frame 201, second frame 311, and third frame 321 are firmly connected to each other.

[0099] Either the first side wall 201c1 or the second side wall 311c1 may be omitted. In other words, it is sufficient that at least one of the first frame 201 and the second frame 311 has a wall portion disposed between the input side gear 205 and the output side gear 312.

[0100] According to the configuration of this embodiment, there is no need to directly mesh the input side gear 205 and the output side gear 312. Therefore, the design freedom for arranging the first side wall 201c1 and the second side wall 311c1 is improved. Furthermore, by connecting the first frame 201 and the second frame 311 with the third frame 321, the rigidity of the first frame 201, the second frame 311, and the third frame 321 can be improved. Furthermore, by fixing the third frame 321 to the first support wall 201b and the second support wall 311b, it is possible to prevent the first support wall 201b and the second support walls 311b1 and 311b2 from shifting relative to each other.

[0101] Furthermore, in this embodiment, the second drive unit 310 and the third drive unit 320 transmit drive force by meshing gears with each other, which increases the degree of freedom in designing the gear layout compared to the configuration of the first embodiment.

[0102] In this embodiment, the drive is transmitted between the first drive unit 200 and the third drive unit 320 via the square shaft 206, and between the second drive unit 310 and the third drive unit 320 by meshing gears. However, the present invention is not limited to this. For example, the drive may be transmitted between the first drive unit 200 and the third drive unit 320 by meshing gears, and between the second drive unit 310 and the third drive unit 320 by meshing gears. [Example]

[0103] Next, a driving device D3 of an image forming apparatus A according to a third embodiment will be described with reference to Figures 7 and 8. The same parts as those in the first and second embodiments will be given the same reference numerals and description thereof will be omitted.

[0104] Fig. 7 is a perspective view of the driving device D3 according to this embodiment. Fig. 8 is a cross-sectional view of the driving device D3 according to this embodiment. Fig. 8 is a cross-sectional view taken along line DD of Fig. 7.

[0105] The drive device D3 according to this embodiment differs from the drive device D2 according to the second embodiment in the configuration of a part of the third drive unit and the second drive unit.

[0106] As shown in Figure 7, the drive units are a first drive unit 200 and a second drive unit 410, which are each fixed to the main frame 99 with screws SC, and a third drive unit 420, which is fixed to the outside of the first frame 201 and the second frame 411 with screws SC.

[0107] The first drive unit 200 has the same configuration as that shown in the first and second embodiments, and therefore a description thereof will be omitted.

[0108] The second drive unit 410 has a second frame (second drive frame) 411 formed from sheet metal (metal plate), a drive shaft (second rotating member) 412 made of metal, and a drive coupling (output portion) 413.

[0109] The third drive unit 420 has a third frame 321 and idler gears 322, 323, and 424. The third frame 321 and the idler gears 322 and 323 are the same as those provided in the third drive unit 320 shown in the second embodiment.

[0110] The driving force of the motor M is transmitted to the drive shaft 412 via the input gear 205, the idler gear 322, the idler gear 323, and the idler gear 424. The drive shaft 412 is rotatable around the second axis A2. In this embodiment, the first axis A1 and the second axis A2 are parallel to each other.

[0111] The second frame 411 is fixed to the main frame 99 and has a second support wall 411b extending in a direction intersecting (orthogonal in this embodiment) the second axis A2, and second side walls 411c1, 411c2, 411c3, and 411c4 extending in the direction of the second axis A2. The second frame 411 is fixed at a position separated from the first frame 201, and a gap is formed between the second frame 411 and the first frame 201. The second support wall 411b is parallel to the main frame 99, and a support portion for the drive shaft 412 is formed on the second support wall 411b. A portion of the drive shaft 412 is located between the second support wall 411b and the main frame 99 in the direction of the second axis A2.

[0112] The second side walls 411c1, 411c2, 411c3, and 411c4 extend in a direction intersecting (orthogonal in this embodiment) the direction in which the second support wall 411b extends. 411c1 faces 411c2, and 411c3 faces 411c4. 411c3 and 411c4 are provided with second fixed portions that are fixed to the main body frame 99 with screws SC. The second fixed portions extend in a direction intersecting (orthogonal in this embodiment) 411c3 and 411c4. The extension direction of 411c1 and 411c2 intersects the extension direction of 411c3 and 411c4.

[0113] The space formed between the second support wall 411b and the main body frame 99 is called the second space. The second side walls 411c1, 411c2, 411c3, and 411c4 are arranged to surround the second space. The drive shaft 412 is housed in the second space. The second frame 411 covers the drive shaft 412 so that at least a portion of the drive shaft 412 is housed in the second space.

[0114] The second frame 411 can also be said to have a box shape formed by the second side walls 411c1, 411c2, 411c3, and 411c4 and the second support wall 411b. The drive shaft 412 is housed in a recess defined by the second side walls 411c1, 411c2, 411c3, and 411c4 and the second support wall 411b. The portion of the second frame 411 facing this recess or the second space can be referred to as the inside of the second frame 411. The portion of the second frame 411 opposite the recess or the second space can be referred to as the outside of the second frame 411.

[0115] The third drive unit 420 has a third frame 321, an idler gear 322, an idler gear 323, and an idler gear (second transmission part, second transmission gear) 424. The idler gear 424 is driven by the idler gear 322 via the idler gear 323, and drives the drive shaft 412. The idler gear 322, the idler gear 323, and the idler gear 424 function as a transmission part configured to transmit the driving force received from the input side gear 205 to the drive shaft 412.

[0116] The idler gear 424 is rotatable around the second axis A2. While the idler gear 324 in the second embodiment meshed with the output gear 312, the idler gear 424 is connected to the drive shaft 412. Furthermore, while the third frame 321 was fixed to the second support wall 311b1 of the second frame 311 in the second embodiment, in the present embodiment, the third frame 321 is fixed to the second support wall 411b of the second frame 411. Except for these points, the configuration of the third drive unit 320 in the second embodiment is the same as that of the third drive unit 420 in the present embodiment.

[0117] The second side wall (wall portion) 411c1 of the second frame 411 is disposed between the input side gear 205 and the drive shaft 412. More specifically, the second side wall 411c1 is disposed between the input side gear 205 and the drive shaft 412 in the direction perpendicular to the second line A2, and faces the drive shaft 412. It can also be said that the second side wall 411c1 is disposed between the first space and the second space.

[0118] Furthermore, similarly to the first embodiment, it is preferable that at least one of the second side walls 411c1, 411c2, 411c3, and 411c4 engage with the main body frame 99. The second side wall 411c1 is engaged with the same hole (engaged portion) as the first side wall 201c1.

[0119] Either the first side wall 201c1 or the second side wall 411c1 may be omitted. In other words, it is sufficient that at least one of the first frame 201 and the second frame 411 has a wall portion disposed between the input gear 205 and the drive shaft 412.

[0120] The idler gear 424 of the third drive unit 420 has a D-cut hole, and the drive shaft 412 also has a D-cut shape and an end that engages with the hole in the idler gear 424. The drive shaft 412 and a drive coupling 413 are also engaged with each other. As a result, the idler gear 424, drive shaft 412, and drive coupling 413 rotate integrally. The drive coupling 413 engages with a coupling 8a provided on the process cartridge 8 arranged inside the main body frame 99, thereby supplying drive force to the process cartridge 8.

[0121] With the above configuration, in addition to the effects already described in the first and second embodiments, in this embodiment, the drive transmitted to the third drive unit 420 is transmitted to the driven part via the drive shaft 412, without passing through an idler gear. Therefore, there is no need to provide a gear train inside the second drive unit 410, which reduces the number of parts and makes it possible to miniaturize the second frame 411. As a result, the space left in the second drive unit 410 can be used effectively, for example, by providing a duct for air flow in the space freed up inside the second drive unit 410.

[0122] The driving devices D1, D2, and D3 can also be attached to the image forming apparatus A and used as a conveying device for conveying the recording material P. [Explanation of symbols]

[0123] A Image forming device 99 Main frame 200 First drive unit 201 1st Frame 210, 310, 410 Second drive unit 211, 311, 411 2nd frame 220, 320, 420 3rd drive unit 221, 321 3rd frame

Claims

1. A drive device provided in an apparatus having a conveying unit that conveys a recording material, The body frame and a first unit including a first rotating member rotatable about a first axis and a first frame fixed to the main body frame and having a first support portion that supports the first rotating member; a second unit including a second rotation member rotatable about a second axis and a second frame fixed to the main body frame and having a second support portion that supports the second rotation member; a transmission unit configured to transmit a driving force received from the first rotating member to the second rotating member; a third frame fixed to the first frame and the second frame; A driving device comprising:

2. the first frame covers the first rotary member so that at least a portion of the first rotary member is housed in a first space formed between the first frame and the main frame; 2. The drive device according to claim 1, wherein the second frame covers the second rotating member so that at least a portion of the second rotating member is housed in a second space formed between the second frame and the main frame.

3. The drive device according to claim 2 , wherein the transmission portion is positioned on an opposite side of the first space with respect to the first frame in the direction of the first axis.

4. The drive device according to claim 1 , wherein the third frame covers the transmission portion.

5. 5. The drive device according to claim 1, wherein the transmission portion is disposed between the first frame and the third frame, and between the second frame and the third frame, in the direction of the first axis.

6. 6. The drive device according to claim 1, wherein at least one of the first frame and the second frame includes a wall portion positioned between the first rotating member and the second rotating member.

7. 7. The drive device according to claim 6, wherein the wall portion has an engaging portion that engages with the main body frame.

8. 8. The drive device according to claim 1, wherein the transmission unit includes a first transmission unit driven by the first rotating member and a second transmission unit driven by the first transmission unit.

9. The drive device according to claim 8, wherein the first transmission part is rotatable about a first axis.

10. 10. The drive device according to claim 8, wherein the second transmission part is rotatable around the second axis.

11. 10. The drive device according to claim 8, wherein the second transmission part is rotatable about a third axis, and the third axis is located at a position spaced apart from the second axis.

12. 12. The drive device according to claim 1, wherein the third frame is formed of a metal plate.

13. The drive device according to claim 1 , wherein the third frame has a third support portion that supports the transmission portion.

14. A drive device according to any one of claims 1 to 13; a transmitted portion to which the driving force is transmitted from the second rotating member; An image forming apparatus comprising:

Images