Sheet conveying device and image forming device

Abstract

To provide a sheet conveying device and an image forming device that can reliably release static electricity accumulated in a first roller and can suppress a first bearing from being damaged when impact is applied on the first roller.SOLUTION: A sheet conveying device 2 includes: a first roller 41; a second roller 42; a first bearing 110 that is made of a conductive resin and supports a first end part 41S1 of a rotating shaft 41S; a second bearing 120 that is made of a material more tenacious than the first bearing 110 and supports the first end 41S1; energizing means 49R that is made of a conductive material and energizes the first bearing 110 in a direction in which the first roller 41 presses the second roller 42; and a frame 90 that supports the second bearing 120 movably in a second direction DF1. The second bearing 120 receives force F1 that moves the rotating shaft 41S in a first direction. The frame 90 restricts the movement of the second bearing 120 receiving the force F1 in the first direction.SELECTED DRAWING: Figure 8

Description

Technical Field

[0001] The present invention relates to a sheet conveying device and an image forming apparatus.

Background Art

[0002] Patent Document 1 discloses an example of a conventional sheet conveying device. This sheet conveying device includes a registration roller pair composed of two rollers.

[0003] As shown in FIGS. 10 to 13 of Patent Document 1, two bearings are attached to a first support portion that supports one end of the rotation shaft of each roller, and a stopper is attached to a stopper attachment portion of the first support portion. The stopper is formed of a conductive resin and serves to prevent detachment from the bearing located above. That is, the stopper is a bearing that indirectly supports one end of the rotation shaft.

[0004] This sheet conveying device is configured to release the static electricity accumulated in the registration roller pair to the ground via the stopper.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, in a conventional sheet conveying device provided with a bearing formed of a conductive resin, such as the sheet conveying device disclosed in Patent Document 1 above, the toughness of the bearing tends to be low. For this reason, when the user carries the sheet conveying device and accidentally drops it, etc., an impact acts on the rotation shaft of the roller, and when the rotation shaft moves suddenly, the bearing is likely to be damaged.

[0007] The present invention has been made in view of the above-described conventional situation, and an object thereof is to provide a sheet conveying device and an image forming apparatus that can reliably release the static electricity accumulated on the first roller and can suppress damage to the first bearing when an impact acts on the first roller.

Means for Solving the Problems

[0008] The sheet conveying device of the present invention includes a first roller having a rotating shaft extending in a first direction and conveying a sheet, a second roller facing the first roller in a second direction orthogonal to the first direction and conveying a sheet, a first bearing formed of a conductive resin and supporting a first end portion on one side of the rotating shaft, a second bearing formed of a material having higher toughness than the first bearing and supporting the first end portion, biasing means formed of a conductive material and biasing the first bearing in a direction in which the first roller presses the second roller, a frame that supports the second bearing movably in the second direction, and the second bearing receives a force that causes the rotating shaft to move in the first direction, the frame is characterized by restricting the movement of the second bearing in the first direction when the rotating shaft receives a force to move in the first direction.

[0009] In the sheet conveying device of the present invention, the first bearing biased by the biasing means in a direction in which the first roller presses the second roller exhibits a function of transmitting the biasing force of the biasing means to the rotating shaft. For this reason, since the first bearing easily adheres to the rotating shaft, the static electricity accumulated on the first roller can be reliably released to the ground via the conductive first bearing and the biasing means from the rotating shaft.

[0010] The second bearing, which is movably supported in the second direction by the frame, aligns the direction in which the first bearing and the rotating shaft move along the second direction, and also aligns the direction of the biasing force of the biasing means along the second direction. When the rotating shaft receives a force to move in the first direction, the second bearing is restricted from moving in the first direction by the frame, and accordingly, the movement of the rotating shaft in the first direction is also restricted.

[0011] With such a division of roles between the first bearing and the second bearing, this sheet conveying device can reduce the functions that the first bearing should perform and simplify the first bearing.

[0012] When the user accidentally drops the sheet conveying device when carrying it, or when an impact acts on the rotating shaft of the first roller and the rotating shaft moves suddenly, the second bearing receives the force for the rotating shaft to move in the first direction and is restricted from moving in the first direction by the frame. As a result, this sheet conveying device can receive the impact transmitted from the rotating shaft by the second bearing formed of a material with higher toughness than the first bearing and the frame, so as to suppress or make zero the impact acting on the first bearing which is likely to have low toughness due to being formed of a conductive resin.

[0013] Therefore, the sheet conveying device of the present invention can reliably release the static electricity accumulated on the first roller, and can suppress the damage of the first bearing when an impact acts on the first roller.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Embodiments for Carrying Out the Invention

[0015] Hereinafter, embodiments embodying the present invention will be described with reference to the drawings.

[0016] (Example) As shown in FIG. 1, the sheet conveyance device 2 of the embodiment is an example of a specific aspect of the sheet conveyance device of the present invention. The image forming apparatus 1 of the embodiment is an example of a specific aspect of the image forming apparatus of the present invention and includes the sheet conveyance device 2. The image forming apparatus 1 is a color printer that forms an image on a sheet by an electrophotographic method.

[0017] <Schematic Configuration of Image Forming Apparatus> The image forming apparatus 1 includes an apparatus main body 9 that is a substantially box-shaped body, an image forming unit 3, a sheet tray 9C, a feeding unit 20, and a discharge roller pair 29 that are housed in the apparatus main body 9. The sheet conveyance device 2 constitutes a part of the feeding unit 20.

[0018] The sheet tray 9C is located below the image forming unit 3. The sheet tray 9C stores the sheets SH before the image is formed in a stacked state. The sheets SH are paper, OHP sheets, etc.

[0019] A discharge tray 9T is formed on the upper surface of the apparatus main body 9. The discharge tray 9T supports the sheet SH after the image formation.

[0020] The apparatus main body 9 has an opening 9H and a front cover 9F. The opening 9H opens in the upper part of the front surface of the apparatus main body 9. The front cover 9F has its lower end side as a swing center axis and closes the opening 9H in an upright state. The front cover 9F swings so that the upper end moves forward and downward as shown by the two-dot chain line in FIG. 1 and protrudes substantially horizontally forward to open the opening 9H.

[0021] The width direction of the image forming apparatus 1 is a direction orthogonal to the front-rear direction and the vertical direction. The side that comes to the right when facing the opening 9H and the front cover 9F of the apparatus main body 9, that is, the back side of the paper surface in FIG. 1, is taken as one side in the width direction. The front-rear direction, the vertical direction, and the width direction shown in each figure after FIG. 2 are displayed corresponding to FIG. 1. The width direction of the image forming apparatus 1 is an example of the "first direction" of the present invention.

[0022] As shown in FIG. 1, the feeding unit 20 is located in front of the image forming unit 3. The feeding unit 20 has a feeding roller 21, a separating roller 22, a separating pad 22A, a pair of conveying rollers 23, and a sheet conveying device 2 arranged along a feeding path P1. Although the specific configuration of the sheet conveying device 2 will be described in detail later, the sheet conveying device 2 includes a registration roller pair 24.

[0023] The feeding path P1 is a path that advances forward and upward from the front end of the sheet tray 9C, then makes a U-turn, and advances backward substantially horizontally to pass through the image forming unit 3.

[0024] The feeding roller 21 sends out the sheet SH accommodated in the sheet tray 9C to the feeding path P1. The separating roller 22 and the separating pad 22A separate the sheets SH sent out by the feeding roller 21 one by one when they are stacked.

[0025] The pair of conveying rollers 23 nip the sheet SH separated one by one by the separating roller 22 and the separating pad 22A and convey it toward the registration roller pair 24.

[0026] The registration roller pair 24 is located at the top of the U-turn portion in the feeding path P1. The registration roller pair 24 has a first roller 41 and a second roller 42. The first roller 41 rotates while sandwiching the sheet SH with the second roller 42.

[0027] The first roller 41 and the second roller 42 are in a stopped state and abut against the leading edge of the sheet SH conveyed toward the first roller 41 and the second roller 42. After a lapse of a predetermined time, they start rotating and convey the sheet SH toward the image forming unit 3. Thereby, skewing of the sheet SH is suppressed.

[0028] Note that the control of the start of rotation of the first roller 41 and the second roller 42 is performed based on the timing when a sheet sensor (not shown) located between the pair of conveying rollers 23 and the registration roller pair 24 in the feeding path P1 detects the leading edge of the sheet SH.

[0029] In this way, the sheet SH fed toward the image forming unit 3 by the feeding unit 20 passes through the image forming unit 3 in a portion of the feeding path P1 that extends substantially horizontally.

[0030] The image forming unit 3 is a direct transfer type color electrophotographic system. The image forming unit 3 includes a drawer 80, a transfer belt 6, a scanner unit 8, and a fixing unit 7.

[0031] Since the drawer 80 has a well-known configuration, its illustration is simplified. It is a frame-like body formed by combining a pair of side walls that are located on the front side and the back side of the paper surface of FIG. 1 and extend in the front-rear direction, and a plurality of connecting members that extend in the width direction and connect both side walls.

[0032] The apparatus main body 9 houses the drawer 80. The position of the drawer 80 shown by the solid line in FIG. 1 is the mounting position mounted on the apparatus main body 9 and is the position for the image forming unit 3 to execute an image forming operation.

[0033] The drawer 80 has four photosensitive drums 5 corresponding to four colors of toner: black, yellow, magenta, and cyan. The drawer 80 rotatably supports each photosensitive drum 5 around an axis extending in the width direction. Each photosensitive drum 5 is arranged in series in the front-rear direction along a portion of the feeding path P1 that extends substantially horizontally.

[0034] The drawer 80 detachably holds four toner cartridges 3C. Each toner cartridge 3C corresponds one-to-one to each photosensitive drum 5 and is arranged in series in the front-rear direction along a portion of the feeding path P1 that extends substantially horizontally. Each toner cartridge 3C houses toner of a corresponding color.

[0035] Each toner cartridge 3C includes a developing roller 3E, a charger 3F, and a toner storage portion 3G, and they are located around each photosensitive drum 5.

[0036] The apparatus main body 9 supports the drawer 80 so as to be movable forward from the mounting position by a guide rail (not shown).

[0037] Drawer 80 is movable between the mounting position shown by the solid line in FIG. 1 and the drawn-out position shown by the two-dot chain line in FIG. 1 in a state where the front cover 9F swings to the position shown by the two-dot chain line in FIG. 1 to open the opening 9H.

[0038] The drawn-out position of the drawer 80 is a position where the drawer 80 is drawn forward from the mounting position. When the drawer 80 is in the drawn-out position and removed from the apparatus main body 9, maintenance operations such as removing the sheet SH clogged in the middle of the feeding path P1 and replacing consumables can be carried out. Although not shown, each toner cartridge 3C can be replaced in a state where the drawer 80 is in the drawn-out position and not removed from the apparatus main body 9. The position of the drawer 80 shown in FIG. 2 is also the drawn-out position.

[0039] As shown in FIG. 1, the transfer belt 6 is positioned below each photosensitive drum 5 with respect to a portion extending substantially horizontally in the feeding path P1. The transfer belt 6 circulates while sandwiching the conveyed sheet SH together with each photosensitive drum 5.

[0040] The scanner unit 8 is positioned above each photosensitive drum 5 and each toner cartridge 3C. The scanner unit 8 has a laser light source, a polygon mirror, an fθ lens, a reflecting mirror, and the like. The scanner unit 8 irradiates each photosensitive drum 5 with a laser beam from above.

[0041] In the drawer 80, the surface of each photosensitive drum 5 is uniformly positively charged by the charger 3F as it rotates, and then exposed by the high-speed scanning of the laser beam irradiated from the scanner unit 8. Thereby, an electrostatic latent image corresponding to the image to be formed on the sheet SH is formed on the surface of each photosensitive drum 5.

[0042] Next, the developing roller 3E supplies the toner stored in the toner storage section 3G to the surface of each photosensitive drum 5 corresponding to the electrostatic latent image, forming a toner image. Then, the first roller 41 and the second roller 42 convey the sheet SH toward each photosensitive drum 5. When the sheet SH passes between each photosensitive drum 5 and the transfer belt 6, the surface facing up of the sheet SH faces each photosensitive drum 5. The toner image carried on the surface of each photosensitive drum 5 is transferred to the surface facing up of the sheet SH.

[0043] The fixing device 7 is located behind the drawer 80. The fixing device 7 heats and presses the sheet SH while conveying it with the heating roller 7A and the pressure roller 7B, thermally fixing the toner image on the sheet SH.

[0044] The discharge roller pair 29 is disposed at the downstream end of the discharge path P2. The discharge path P2 guides the sheet SH that has passed through the fixing device 7 upward and U-turns it so that the surface on which the image is formed faces downward and discharges it to the discharge tray 9T. The discharge roller pair 29 nips the sheet SH conveyed along the discharge path P2 and discharges it to the discharge tray 9T.

[0045] <Specific Configuration of the Sheet Conveying Device> The sheet conveying device 2 includes the first roller 41 shown in FIGS. 2 to 10, the second roller 42 shown in FIGS. 2 and 3, the frame 90 shown in FIGS. 2 to 6, 9, and 10, and the chute sheet metal 98 shown in FIGS. 2, 5, and 6.

[0046] The sheet conveying device 2 also includes the first bearing 110 and the second bearing 120 shown in FIGS. 2 to 4 and 6 to 9, and the third bearing 130 shown in FIGS. 2 to 5, 7, 8, and 10.

[0047] Furthermore, the sheet conveying device 2 includes a compression coil spring 49L shown in FIGS. 3, 7, 8, and 10, and a compression coil spring 49R shown in FIGS. 3 and 6 to 9. The compression coil springs 49L and 49R are identical components and are formed of a metallic wire material which is a conductive material. The compression coil spring 49R located on one side in the width direction is an example of the "biasing means" of the present invention.

[0048] <First roller> As shown in FIGS. 7 and 9, the first roller 41 has a rotating shaft 41S and a roller body 41A. The rotating shaft 41S is a metallic cylinder extending in the width direction. The roller body 41A is a cylindrical body fixed to the rotating shaft 41S.

[0049] One first end portion 41S1 of the rotating shaft 41S protrudes in one direction in the width direction from the roller body 41A. The rotating shaft 41S has a C-shaped retaining ring 41C1. The C-shaped retaining ring 41C1 is located in the vicinity of the roller body 41A at the first end portion 41S1 of the rotating shaft 41S and is fitted in a groove recessed in one circumference. The C-shaped retaining ring 41C1 protrudes outward in the radial direction from the rotating shaft 41S. The C-shaped retaining ring 41C1 is an example of the "protruding portion" of the present invention. The support configuration of the first end portion 41S1 of the rotating shaft 41S will be described later.

[0050] As shown in FIG. 10, the other second end portion 41S2 of the rotating shaft 41S protrudes in the other direction in the width direction from the roller body 41A. The rotating shaft 41S has a C-shaped retaining ring 41C2. The C-shaped retaining ring 41C2 is located in the vicinity of the roller body 41A at the second end portion 41S2 of the rotating shaft 41S and is fitted in a groove recessed in one circumference. The C-shaped retaining ring 41C2 protrudes outward in the radial direction from the rotating shaft 41S. The support configuration of the second end portion 41S2 of the rotating shaft 41S will be described later.

[0051] The portion of the second end 41S2 of the rotating shaft 41S, which is located on the other side in the width direction from the C-shaped retaining ring 41C2, is fitted into the coupling 52. The coupling 52 has a cylindrical outer peripheral surface 52A and a connecting portion 52J located on the other side in the width direction from the outer peripheral surface 52A. One end in the width direction of the joint shaft 55 is connected to the connecting portion 52J.

[0052] As shown in FIG. 3, the other end in the width direction of the joint shaft 55 is connected to a connecting portion 50J integrally formed with the drive gear 50. The driving force of a drive motor (not shown) is transmitted to the rotating shaft 41S via the connecting portion 50J of the drive gear 50, the joint shaft 55, and the coupling 52, causing the first roller 41 to rotate.

[0053] <The second roller and the second roller bearing> As shown in FIG. 2, the drawer 80 has second roller bearings 82L and 82R. The second roller bearing 82R is located at one corner on the front side and the lower side of the drawer 80 in the width direction. The second roller bearing 82L is located at the other corner on the front side and the lower side of the drawer 80 in the width direction.

[0054] Although the drawer 80 is not shown in FIG. 3, the positions of the second roller bearings 82L and 82R shown in FIG. 3 correspond to the drawer 80 in the mounting position.

[0055] As shown in FIGS. 2 and 3, the second roller 42 has a second roller rotating shaft 42S and a second roller main body 42A. The second roller rotating shaft 42S is a metal cylinder extending in the width direction. The second roller main body 42A is a cylindrical body fixed to the second roller rotating shaft 42S with both ends in the width direction of the second roller rotating shaft 42S exposed.

[0056] The second roller 42 is rotatably supported by the drawer 80 by the second roller bearings 82L and 82R supporting both ends in the width direction of the second roller rotating shaft 42S.

[0057] A transmission gear 56 is fixed to a portion of the second roller rotating shaft 42S that protrudes to the other side in the width direction from the second roller bearing 82L. As shown in FIG. 3, with the drawer 80 in the mounted position, the transmission gear 56 meshes with the drive gear 50, and the second roller 42 faces the first roller 41 from above at a position shifted forward with respect to the first roller 41.

[0058] The direction in which the second roller 42 faces the first roller 41 is a facing direction DF1 that is orthogonal to the width direction and is inclined with respect to the vertical direction. The facing direction DF1 is an example of the "second direction" of the present invention.

[0059] When the driving force of a driving motor (not shown) is transmitted to the second roller rotating shaft 42S via the drive gear 50 and the transmission gear 56, the second roller 42 rotates in synchronization with the first roller 41.

[0060] As shown in FIG. 2, the second roller 42 moves forward and away from the first roller 41 as the drawer 80 moves from the mounted position to the pulled-out position.

[0061] As shown in FIG. 3, the second roller bearings 82L and 82R have a holding portion 88 and a releasing portion 89.

[0062] The holding portion 88 is formed in a portion of the second roller bearings 82L and 82R that is located below and behind the second roller rotating shaft 42S, and is a groove that is concave upward and slightly forward so as to approach the first roller rotating shaft 41S. The holding portion 88 is concave along the facing direction DF1.

[0063] The releasing portion 89 is connected to the rearward and downward end of the holding portion 88, and is an inclined surface that faces downward, extends rearward and downward.

[0064] <Frame and chute sheet metal> As shown in FIG. 4, the frame 90 is a resin molded product that forms part of a plurality of internal frames provided in the apparatus main body 9, and extends in the width direction. One end of the frame 90 in the width direction is connected to a side frame (not shown) located on one side surface side of the apparatus main body 9 in the width direction. The other end of the frame 90 in the width direction is connected to another side frame (not shown) located on the other side surface side of the apparatus main body 9 in the width direction.

[0065] As shown in FIGS. 2, 5, and 6, below the frame 90, a feed frame 96 is located. The feed frame 96 is also a resin molded product that forms part of a plurality of internal frames provided in the apparatus main body 9, and extends in the width direction.

[0066] As shown in FIG. 6, the feed frame 96 is fastened to the frame 90 and rotatably supports one roller of the pair of conveying rollers 23. Also, as shown in FIG. 2, the feed frame 96 rotatably supports the separating roller 22.

[0067] As shown in FIGS. 2, 5, and 6, the chute sheet metal 98 is formed of a metal sheet material, is located in front of the frame 90, and extends in the width direction. Plate-like pieces are formed at one end edge and the other end edge of the chute sheet metal 98 in the width direction, and these plate-like pieces are fastened to one end and the other end of the frame 90 in the width direction. The chute sheet metal 98 extends vertically upward from its lower end edge and then curves backward. The upper end edge of the chute sheet metal 98 is located near the upper end of the roller body 41A.

[0068] The chute sheet metal 98 guides the sheet SH conveyed by the pair of conveying rollers 23 toward the first roller 41 and the second roller 42.

[0069] <Rails, spring pedestals, and guide convex portions of the frame> As shown in FIG. 4, the frame 90 has rails 93L, 93R. The rails 93L, 93R are located outside the roller body 41A of the first roller 41 in the width direction.

[0070] As shown in FIGS. 4 and 6, the rail 93R located on one side in the width direction extends upward and slightly forward along the opposing direction DF1 from a position below the first end portion 41S1 of the rotating shaft 41S. The upper end of the rail 93R is located in front of the first end portion 41S1 of the rotating shaft 41S.

[0071] As shown in FIG. 5, the rail 93L located on the other side in the width direction has substantially the same shape as the rail 93R located on one side in the width direction but is offset. The rail 93L extends upward and slightly forward along the opposing direction DF1 from a position below the second end portion 41S2 of the rotating shaft 41S. The upper end of the rail 93L is located in front of the second end portion 41S2 of the rotating shaft 41S.

[0072] As shown in FIG. 3, the frame 90 has spring pedestals 95L and 95R. The spring pedestals 95L and 95R are located outside the roller body 41A of the first roller 41 in the width direction.

[0073] As shown in FIGS. 3 and 6, the spring pedestal 95R located on one side in the width direction is located behind the rail 93R. The spring pedestal 95R locks the lower end of the compression coil spring 49R. As shown in FIG. 9, a guide convex portion 94R is formed on the side surface of the spring pedestal 95R facing one side in the width direction so as to protrude in one side in the width direction.

[0074] As shown in FIG. 3, the spring pedestal 95L located on the other side in the width direction has substantially the same shape as the spring pedestal 95R located on one side in the width direction but is offset. The spring pedestal 95L is located behind the rail 93L. The spring pedestal 95L locks the lower end of the compression coil spring 49L. As shown in FIGS. 5 and 10, a guide convex portion 94L is formed on the side surface of the spring pedestal 95L facing the other side in the width direction so as to protrude in the other side in the width direction.

[0075] <The First Bearing and the Second Bearing> As shown in FIGS. 7 and 8, the first bearing 110 is a member having a first bearing body 111, a locking portion 119 and an intermediate portion 116 integrally formed with the first bearing body 111.

[0076] The first bearing 110 is formed of a conductive resin. In this embodiment, the first bearing 110 is formed of a thermoplastic resin containing a conductive filler such as carbon black and metal powder. The conductive resin tends to have a lower toughness compared to the thermoplastic resin before the conductive filler is mixed in. Note that toughness represents the stickiness of a material. In other words, it represents the property of being difficult to be broken against an external force. Since the toughness of the conductive resin is lower than that of the polyacetal resin (POM) described later, it becomes brittle and is easily damaged by an external force.

[0077] The first bearing body 111 has a cylindrical shape with an inner diameter slightly larger than the outer diameter of the first end portion 41S1 of the rotating shaft 41S. The locking portion 119 is located below the first bearing body 111. The intermediate portion 116 connects the first bearing body 111 and the locking portion 119.

[0078] As shown in FIGS. 6 and 9, the first bearing body 111 inserts the first end portion 41S1 of the rotating shaft 41S. The locking portion 119 locks the upper end of the compression coil spring 49R. The upper end of the compression coil spring 49R is an example of "one end of the biasing means" of the present invention. A cavity is formed in the intermediate portion 116, and the cavity penetrates the intermediate portion 116 in the width direction.

[0079] As shown in FIGS. 7 and 8, the first bearing body 111 has a fitting recess 115. The fitting recess 115 is recessed from the upper portion of the end face located on one side in the width direction of the first bearing body 111 toward the other side in the width direction.

[0080] The second bearing 120 is a member having a second bearing body 121, a regulated portion 123, a plate-like piece 128 and an intermediate portion 126 integrally formed with the second bearing body 121.

[0081] The second bearing 120 is formed of a non-conductive resin, which is a material with higher toughness than the first bearing 110. In this embodiment, the second bearing 120 is formed of polyoxymethylene resin (POM) that does not contain a conductive filler. Polyoxymethylene resin (POM) is an engineering plastic excellent in sliding characteristics, toughness, and fatigue characteristics.

[0082] The second bearing body 121 has a cylindrical shape with an inner diameter slightly larger than the outer diameter of the first end portion 41S1 of the rotating shaft 41S. The second bearing body 121 has a fitting convex portion 125. The fitting convex portion 125 protrudes from the upper portion of the end face located on the other side in the width direction of the second bearing body 121 toward the other side in the width direction. The fitting convex portion 125 protrudes so as to bite into the fitting concave portion 115 of the first bearing body 111 in the width direction.

[0083] The restricted portion 123 is located on the other side and in front of the second bearing body 121 in the width direction, and is also located slightly below the second bearing body 121. The restricted portion 123 has a substantially "C" shape when viewed along the facing direction DF1 and is open forward. The front end portion located on one side in the width direction of the restricted portion 123 is bent toward the other side in the width direction.

[0084] The intermediate portion 126 connects the second bearing body 121 and the restricted portion 123. As shown in FIG. 7, the intermediate portion 126 has an engaging protrusion 126A. The engaging protrusion 126A protrudes in a cantilever shape toward the other side in the width direction, and the tip thereof has a key claw shape.

[0085] The plate-like piece 128 is connected to the end portion located below and on one side in the width direction of the intermediate portion 126 and protrudes downward. The plate-like piece 128 has a long hole 128H that is long in the facing direction DF1.

[0086] As shown in FIG. 9, the second bearing body 121 is located on one side in the width direction relative to the first bearing body 111 of the first bearing 110 and inserts the first end portion 41S1 of the rotating shaft 41S. In other words, the first bearing body 111 of the first bearing 110 is located between the second bearing body 121 of the second bearing 120 and the C-shaped retaining ring 41C1 in the width direction.

[0087] The fitting recess 115 fits with the fitting projection 125 of the second bearing body 121 to restrict relative rotation around the rotating shaft 41S between the first bearing body 111 and the second bearing body 121.

[0088] As shown in FIG. 6, the engaging projection 126A passes through the cavity of the intermediate portion 116 of the first bearing body 111. As shown in FIG. 3, the engaging projection 126A engages the key claw at the tip with the other end face in the width direction of the intermediate portion 116, thereby maintaining the state where the first bearing body 111 and the second bearing body 121 are in contact in the width direction.

[0089] As shown in FIG. 4, the restricted portion 123 holds the rail 93R of the frame 90. The restricted portion 123 is restricted by the rail 93R from moving in the width direction and from moving in a direction orthogonal to the width direction and the opposing direction DF1.

[0090] As shown in FIG. 9, the plate-like piece 128 is adjacent to the spring pedestal 95R from one side in the width direction, and the guide projection 94R is inserted through the long hole 128H.

[0091] In this way, the frame 90 supports the second bearing 120 so as to be movable in the opposing direction DF1 by the rail 93R and the guide projection 94R.

[0092] The first bearing 110 and the second bearing 120 support the first end portion 41S1 of the rotating shaft 41S. When the second bearing 120 moves in the opposing direction DF1, the first bearing 110 and the first end portion 41S1 also move in the opposing direction DF1 together with the second bearing 120.

[0093] The compression coil spring 49R biases the first bearing 110 in the direction in which the first roller 41 presses the second roller 42, that is, in the direction along the opposing direction DF1.

[0094] As shown in FIG. 3, the holding portion 88 of the second roller bearing 82R holds the second bearing body 121 of the second bearing 120 so as to be movable in the opposing direction DF1 in a state where the drawer 80 is in the mounted position.

[0095] When the drawer 80 starts to move from the mounted position to the pulled-out position, the release portion 89 of the second roller bearing 82R presses the second bearing body 121 of the second bearing 120 downward to release the pressing of the first roller 41 against the second roller 42.

[0096] As shown in FIG. 9, let the range in which the compression coil spring 49R exists in the width direction be A1. Let the range in which the first bearing 110 exists in the width direction be A2. Let the range in which the restricted portion 123 of the second bearing 120 exists in the width direction be A3. The range A2 includes the entire range A1, and the range A3 includes the entire ranges A1 and A2. That is, in the width direction, the first bearing 110 and the restricted portion 123 of the second bearing 120 are in the same position.

[0097] <Third bearing> As shown in FIGS. 7 and 8, the third bearing 130 is a member having a third bearing body 131, a locking portion 139, a restricted portion 133, and a plate-like piece 138 that are integrally formed with the third bearing body 131.

[0098] The third bearing 130 is formed of a non-conductive resin, which is a material having higher toughness than the first bearing 110. In this embodiment, the third bearing 130 is formed of polyacetal resin (POM) that does not contain a conductive filler, similar to the second bearing 120.

[0099] As shown in FIG. 10, the third bearing body 131 has a cylindrical shape with an inner diameter slightly larger than the outer diameter of the outer peripheral surface 52A of the coupling 52 into which the second end portion 41S2 of the rotating shaft 41S is fitted. The locking portion 139 is located below the third bearing body 131 and is connected to the third bearing body 131.

[0100] As shown in FIG. 8, the regulated portion 133 is located in front of and slightly below the third bearing body 131 and is connected to the third bearing body 131. The regulated portion 133 has a substantially "C" shape when viewed along the facing direction DF1 and is open forward. The front end portion located on the other side in the width direction of the regulated portion 133 is bent toward one side in the width direction.

[0101] As shown in FIGS. 8 and 10, the plate-like piece 138 is connected to an end portion located below and on the other side in the width direction of the locking portion 139 and protrudes downward. The plate-like piece 138 has a long hole 138H that is long in the facing direction DF1.

[0102] As shown in FIG. 10, the third bearing body 131 inserts the second end portion 41S2 with the coupling 52 interposed therebetween and the second end portion 41S2 of the rotating shaft 41S. The locking portion 139 locks the upper end of the compression coil spring 49L.

[0103] As shown in FIG. 5, the regulated portion 133 holds the rail 93L of the frame 90. The regulated portion 133 is regulated by the rail 93L from moving in the width direction and from moving in a direction orthogonal to the width direction and the facing direction DF1.

[0104] As shown in FIG. 10, the plate-like piece 138 is adjacent to the spring pedestal 95L from the other side in the width direction, and the guide convex portion 94L is inserted through the long hole 138H.

[0105] In this way, the frame 90 supports the third bearing 130 so as to be movable in the facing direction DF1 by the rail 93L and the guide convex portion 94L.

[0106] The third bearing 130 supports the second end portion 41S2 of the rotating shaft 41S. When the third bearing 130 moves in the facing direction DF1, the second end portion 41S2 also moves in the facing direction DF1 together with the third bearing 130.

[0107] The compression coil spring 49L biases the third bearing 130 in the direction in which the first roller 41 presses the second roller 42, that is, along the facing direction DF1.

[0108] As shown in FIG. 3, the holding portion 88 of the second roller bearing 82L holds the third bearing body 131 of the third bearing 130 so as to be movable in the facing direction DF1 in a state where the drawer 80 is in the mounting position.

[0109] When the drawer 80 starts to move from the mounting position to the pulling-out position, the releasing portion 89 of the second roller bearing 82L presses the third bearing body 131 of the third bearing 130 downward to release the pressing of the first roller 41 against the second roller 42.

[0110] <Actions of the first bearing and the second bearing when the rotating shaft receives a force to move in the width direction> When the user carries the image forming apparatus 1 including the sheet conveying apparatus 2 and accidentally drops it or the like, an impact may act on the rotating shaft 41S of the first roller 41, and the rotating shaft 41S may move suddenly.

[0111] In this case, as shown in FIG. 9, when the rotating shaft 41S moves in one direction in the width direction, the force F1 causing the rotating shaft 41S to move in the width direction is transmitted to the first bearing 110 when the C-shaped retaining ring 41C1 moves in one direction in the width direction and abuts against the first bearing body 111 of the first bearing 110. Then, the second bearing 120 receives the force F1 causing the rotating shaft 41S to move in the width direction via the second bearing body 121 that abuts against the first bearing body 111 of the first bearing 110 in the width direction.

[0112] That is, when the rotating shaft 41S moves in one direction in the width direction, the second bearing 120 receives the force F1 causing the rotating shaft 41S to move in the width direction with the first bearing 110 interposed therebetween.

[0113] The rail 93R of the frame 90 restricts the movement in the width direction of the second bearing 120 that has received the force F1 causing the rotation shaft 41S to move in the width direction via the restricted portion 123. As a result, the frame 90 receives the force F1 causing the rotation shaft 41S to move in the width direction via the rail 93R. Since the frame 90 is a large resin molded product, it can suitably support the force F1.

[0114] <Action of the third bearing when the rotation shaft receives a force to move in the width direction> As shown in FIG. 10, when an impact acts on the rotation shaft 41S of the first roller 41 and the rotation shaft 41S moves suddenly, when the rotation shaft 41S moves to the other side in the width direction, a force FR1 opposite to the force F1 received by the second bearing 120 from the rotation shaft 41S acts on the rotation shaft 41S, and the C-shaped retaining ring 41C2 moves to the other side in the width direction and abuts against the third bearing body 131 of the third bearing 130.

[0115] That is, the third bearing 130 directly receives the force FR1 opposite to the force F1 received by the second bearing 120 from the rotation shaft 41S.

[0116] The rail 93L of the frame 90 restricts the movement in the width direction of the third bearing 130 that has received the force FR1 opposite to the force F1 via the restricted portion 133. As a result, the frame 90 receives the force FR1 opposite to the force F1 via the rail 93L. Since the frame 90 is a large resin molded product, it can suitably support the force FR1.

[0117] <Configuration for discharging static electricity accumulated in the first roller and the chute sheet metal> As shown in FIG. 6, the sheet conveying device 2 further includes a frame sheet metal 99 and ground connection members 97, 97S.

[0118] The frame sheet metal 99 is a reinforcing member having a substantially "L" - shaped cross - section formed of a metal sheet material and extends in the width direction. Although not shown, one end of the frame sheet metal 99 in the width direction is connected to a side frame located on one side surface in the width direction of the apparatus main body 9. The other end of the frame sheet metal 99 in the width direction is connected to another side frame located on the other side surface in the width direction of the apparatus main body 9. The frame sheet metal 99 is connected to the ground E1.

[0119] The ground connection member 97 is a member formed of a metal wire and bent at a plurality of locations. The ground connection member 97S is a compression coil spring formed of a metal wire. The rear end of the ground connection member 97S is in contact with the frame sheet metal 99. The rear end of the ground connection member 97 is in contact with the front end of the ground connection member 97S.

[0120] The ground connection member 97 has a first portion 97A, a second portion 97B, and a third portion 97C. As shown in FIGS. 4 and 6, the first portion 97A includes the front end of the ground connection member 97 and protrudes forward and downward from the front surface of the frame 90. As shown in FIG. 6, the first portion 97A is in contact with the chute sheet metal 98. The second portion 97B is connected to the first portion 97A and extends rearward, passing through the frame 90. The third portion 97C is connected to the second portion 97B and extends rearward and upward, contacting the lower end of the compression coil spring 49R.

[0121] In this way, by the ground connection members 97, 97S contacting the frame sheet metal 99, the compression coil spring 49R, and the chute sheet metal 98, the static electricity accumulated on the first roller 41 and the chute sheet metal 98 by contacting the seat SH can be discharged to the ground E1.

[0122] <Function and effect> In the sheet conveying device 2 of the embodiment, as shown in FIG. 6, the first bearing 110 biased in the direction in which the first roller 41 presses the second roller 42 by the compression coil spring 49R, that is, in the direction along the opposing direction DF1, exhibits the function of transmitting the biasing force of the compression coil spring 49R to the rotating shaft 41S. Therefore, since the first bearing 110 easily adheres to the rotating shaft 41S, the static electricity accumulated on the first roller 41 can be reliably discharged from the rotating shaft 41S to the ground E1 via the conductive first bearing 110, the compression coil spring 49R, the ground connection members 97, 97S, and the frame sheet metal 99.

[0123] As shown in FIGS. 4 and 9, the second bearing 120 movably supported in the opposing direction DF1 by the rail 93R and the guide convex portion 94R of the frame 90 causes the first bearing 110 and the rotating shaft 41S to move in the direction along the opposing direction DF1, and also causes the direction of the biasing force of the compression coil spring 49R to be along the opposing direction DF1.

[0124] Then, as shown in FIG. 9, when the rotating shaft 41S moves in one direction in the width direction, the force F1 causing the rotating shaft 41S to move in the width direction is transmitted to the first bearing 110 when the C-shaped retaining ring 41C1 moves in one direction in the width direction and abuts against the first bearing body 111 of the first bearing 110. Then, the second bearing 120 receives the force F1 causing the rotating shaft 41S to move in the width direction via the second bearing body 121 that abuts against the first bearing body 111 of the first bearing 110 in the width direction.

[0125] The rail 93R of the frame 90 restricts the movement of the second bearing 120 in the width direction that has received the force F1 causing the rotating shaft 41S to move in the width direction via the restricted portion 123. Accordingly, the movement of the rotating shaft 41S in one direction in the width direction is also restricted.

[0126] By such role sharing between the first bearing 110 and the second bearing 120, the sheet conveying device 2 can reduce the functions that the first bearing 110 should exhibit, and the first bearing 110 can be simplified.

[0127] When the user accidentally drops the image forming apparatus 1 when carrying it, and an impact acts on the rotation shaft 41S of the first roller 41 and the rotation shaft 41S moves suddenly, the second bearing 120 receives the force F1 that causes the rotation shaft 41S to move in the width direction with the first bearing 110 interposed therebetween, and the movement in the width direction is restricted by the rail 93R of the frame 90.

[0128] As a result, this sheet conveyance device 2 can receive the impact transmitted from the rotation shaft 41S by the second bearing 120 formed of a material having higher toughness than the first bearing 110 and the frame 90, so that the impact acting on the first bearing 110, which is likely to have low toughness due to being formed of a conductive resin, can be suppressed or made zero.

[0129] Therefore, the sheet conveyance device 2 of the embodiment can reliably release the static electricity accumulated in the first roller 41, and can suppress the breakage of the first bearing 110 when an impact acts on the first roller 41.

[0130] Also, in the sheet conveyance device 2, as shown in FIG. 10, the third bearing 130 that supports the second end portion 41S2 of the rotation shaft 41S is formed of a material having higher toughness than the first bearing 110. The third bearing 130 receives a force FR1 that is opposite to the force F1 received by the second bearing 120 from the rotation shaft 41S. The rail 93L of the frame 90 restricts the movement in the width direction of the third bearing 130 that has received the opposite force FR1. With this configuration, when an impact acts on the rotation shaft 41S of the first roller 41 and the rotation shaft 41S moves suddenly, the third bearing 130 that receives a force FR1 opposite to the force F1 received by the second bearing 120 from the rotation shaft 41S can receive the impact transmitted from the rotation shaft 41S.

[0131] Furthermore, in the sheet conveying device 2, as shown in FIG. 4, the second bearing 120 has a regulated portion 123 whose movement in the width direction is regulated by the rail 93R of the frame 90. And, as shown in FIG. 9, the range A2 where the first bearing 110 exists in the width direction includes the entire range A1 where the compression coil spring 49R exists in the width direction. The range A3 where the regulated portion 123 of the second bearing 120 exists in the width direction includes the entire ranges A1 and A2. That is, in the width direction, the first bearing 110 and the regulated portion 123 of the second bearing 120 are at the same position. When the biasing force of the compression coil spring 49R is transmitted to the first bearing 110 and then from the first bearing 110 to the rotating shaft 41S, since the second bearing 120 is movably supported in the opposing direction DF1 by the rail 93R of the frame 90, the biasing force of the compression coil spring 49R is along the opposing direction DF1. Also, since the second bearing 120 that receives the force F1 causing the rotating shaft 41S to move in the width direction is regulated in its movement in the width direction by the rail 93R of the frame 90, the movement of the rotating shaft 41S in the width direction is also regulated. Here, in the width direction, since the first bearing 110 and the regulated portion 123 of the second bearing 120 are at the same position, it becomes difficult for the direction of the biasing force of the compression coil spring 49R to be inclined with respect to the opposing direction DF1. Therefore, the compression coil spring 49R can efficiently bias the rotating shaft 41S to move in the opposing direction DF1. As a result, this sheet conveying device 2 can reliably transmit the biasing force of the compression coil spring 49R to the rotating shaft 41S of the first roller 41 with high certainty.

[0132] Also, in the sheet conveying device 2, as shown in FIG. 9, the first bearing body 111 of the first bearing 110 is positioned between the second bearing body 121 of the second bearing 120 and the C-shaped retaining ring 41C1 in the width direction. When the rotating shaft 41S moves in one direction in the width direction, the C-shaped retaining ring 41C1 abuts against the first bearing body 111 of the first bearing 110. The second bearing 120 receives the force F1 causing the rotating shaft 41S to move in the width direction via the first bearing body 111 of the first bearing 110 that abuts against the C-shaped retaining ring 41C1 and the second bearing body 121 that abuts in the width direction. With such a simple configuration, the second bearing 120 can receive the force F1 causing the rotating shaft 41S to move in the width direction.

[0133] Further, in the sheet conveying device 2, as shown in FIGS. 7 and 9, when the fitting recess 115 of the first bearing body 111 fits with the fitting projection 125 of the second bearing body 121, relative rotation around the rotation axis 41S between the first bearing body 111 and the second bearing body 121 is restricted. With this configuration, the frame 90 can reliably restrict the displacement of the locking portion 119 of the first bearing 110 around the rotation axis 41S via the rail 93R, the restricted portion 123 of the second bearing 120 and the second bearing body 121, and the first bearing body 111 of the first bearing 110. As a result, the first bearing 110 can reliably exhibit the function of transmitting the biasing force of the compression coil spring 49R to the rotation axis 41S in the facing direction DF1.

[0134] Also, in the sheet conveying device 2, as shown in FIG. 6, the ground connection members 97, 97S are in contact with the frame sheet metal 99 and the compression coil spring 49R. With this configuration, the degree of freedom in arranging the ground path from the compression coil spring 49R to the frame sheet metal 99 can be improved.

[0135] Furthermore, in the sheet conveying device 2, the ground connection member 97 has a first portion 97A that abuts against the chute sheet metal 98 and a second portion 97B that penetrates the frame 90. With this configuration, it is possible to suppress an increase in the length of the ground path from the chute sheet metal 98 to the compression coil spring 49R as compared with a configuration in which the ground connection member 97 bypasses the frame 90 without having the second portion 97B.

[0136] Also, in the sheet conveying device 2, the second bearing 120 is formed of a non-conductive resin. With this configuration, it is possible to easily make the toughness of the second bearing 120 higher than the toughness of the first bearing 110.

[0137] Furthermore, in the image forming apparatus 1 of the embodiment, as shown in FIG. 3, the drawer 80 includes a holding portion 88 that holds the second bearing body 121 of the second bearing 120 movably in the facing direction DF1 in a state where the drawer 80 is in the mounted position, and a releasing portion 89 that presses the second bearing body 121 of the second bearing 120 to release the pressing of the first roller 41 against the second roller 42 when the drawer 80 starts to move from the mounted position to the pulled-out position. With this configuration, the second bearing body 121 of the second bearing 120 formed of a material having higher toughness than the first bearing 110 is held by the holding portion 88 of the drawer 80 or pushed by the releasing portion 89. As a result, the image forming apparatus 1 can achieve an improvement in durability as compared with a configuration in which the drawer 80 holds or pushes the first bearing 110, which is likely to have low toughness due to being formed of a conductive resin, by the holding portion 88.

[0138] As described above, the present invention has been described with reference to the embodiments. However, the present invention is not limited to the above embodiments, and it goes without saying that the present invention can be appropriately modified and applied without departing from the gist thereof.

[0139] (Modification Example 1) As shown in FIG. 11, in the sheet conveyance device of Modification Example 1, instead of fitting the C-shaped retaining ring 41C1 to the first end portion 41S1 of the sheet conveyance device 2 of the embodiment, a flange 41F is integrally formed on the first end portion 41S1. The flange 41F is located between the roller body 41A and the first bearing body 111 and protrudes radially outward from the first end portion 41S1. The flange 41F is an example of the "protruding portion" of the present invention.

[0140] Also, in this sheet conveyance device, the first end portion 41S1 according to the embodiment is extended to protrude in one direction in the width direction from the second bearing body 121, and the C-shaped retaining ring 41C3 is fitted to the protruding portion. The C-shaped retaining ring 41C3 is an example of the "protruding portion" of the present invention. Note that the C-shaped retaining ring 41C2 that fits to the second end portion 41S2 according to the embodiment may be left as it is or may be omitted.

[0141] Other configurations of Modification 1 are the same as those of the embodiment. Therefore, the same reference numerals are given to the same configurations as those of the embodiment, and the description thereof is omitted or simplified.

[0142] When the rotation shaft 41S moves to one side in the width direction, the force F21 for the rotation shaft 41S to move in the width direction is transmitted to the first bearing 110 by the flange 41F moving to one side in the width direction and contacting the first bearing body 111 of the first bearing 110. Then, the second bearing 120 receives the force F21 for the rotation shaft 41S to move in the width direction via the second bearing body 121 that contacts the first bearing body 111 of the first bearing 110 in the width direction.

[0143] When the rotation shaft 41S moves to the other side in the width direction, the force F22 for the rotation shaft 41S to move in the width direction is opposite to the force F21. The force F22 for the rotation shaft 41S to move in the width direction is transmitted to the second bearing 120 by the C-shaped retaining ring 41C3 moving to the other side in the width direction and contacting the second bearing body 121 of the second bearing 120. That is, the second bearing 120 directly receives the force F22 for the rotation shaft 41S to move in the width direction.

[0144] The sheet conveying device of Modification 1 having such a configuration can also achieve the same operational effects as the sheet conveying device 2 of the embodiment.

[0145] (Modification 2) As shown in FIG. 12, in the sheet conveying device of Modification 2, the C-shaped retaining ring 41C1 that fits onto the first end portion 41S1 of the sheet conveying device 2 of the embodiment is eliminated. Then, the first end portion 41S1 is extended to protrude to one side in the width direction from the second bearing body 121, and the C-shaped retaining ring 41C3 is fitted onto the protruding portion. The C-shaped retaining ring 41C3 is an example of the "protruding portion" of the present invention.

[0146] Also, in this sheet conveying device, the coupling 52 is eliminated from the second end portion 41S2 according to the embodiment, and the third bearing body 131 of the third bearing 130 is changed to directly support the second end portion 41S2.

[0147] Furthermore, in this sheet conveying device, the transmission gear 55G is fixed to the second end portion 41S2, and the driving force of a driving motor (not shown) is changed to be transmitted to the rotating shaft 41S via the transmission gear 55G.

[0148] Also, in this sheet conveying device, a C-shaped retaining ring 41C4 is fitted at a position between the third bearing body 131 and the transmission gear 55G at the second end portion 41S2.

[0149] Other configurations of the second modification are the same as those of the embodiment. Therefore, the same reference numerals are given to the same configurations as those of the embodiment, and the description thereof is omitted or simplified.

[0150] When the rotating shaft 41S moves toward the other side in the width direction, the force F31 for the rotating shaft 41S to move in the width direction is transmitted to the second bearing 120 by the C-shaped retaining ring 41C3 moving toward the other side in the width direction and contacting the second bearing body 121 of the second bearing 120. That is, the second bearing 120 directly receives the force F31 for the rotating shaft 41S to move in the width direction.

[0151] When the rotating shaft 41S moves toward one side in the width direction, a force FR31 opposite to the force F31 received by the second bearing 120 from the rotating shaft 41S acts on the rotating shaft 41S, and the C-shaped retaining ring 41C4 moves toward one side in the width direction and contacts the third bearing body 131 of the third bearing 130. That is, the third bearing 130 directly receives the force FR31 opposite to the force F31 received by the second bearing 120 from the rotating shaft 41S.

[0152] The sheet conveying device of the second modification having such a configuration can also achieve the same operational effects as the sheet conveying device 2 of the embodiment.

[0153] In the embodiment, the sheet conveying device of the present invention is embodied as the sheet conveying device 2 provided in the image forming apparatus 1, but the present invention is not limited to this configuration. For example, the configuration of the present invention may be applied to an image reading device, or may be applied to a multifunction machine having an image reading device above the image forming apparatus.

[0154] In the embodiment, the second bearing body 121 has a fitting convex portion 125 and the first bearing body 111 has a fitting concave portion 115, but the present invention is not limited to this configuration. For example, a configuration in which the first bearing body has a fitting convex portion and the second bearing body has a fitting concave portion is also included in the present invention.

[0155] In the embodiment, the first portion 97A and the second portion 97B of the ground connection member 97 are continuous, but the present invention is not limited to this configuration. For example, with respect to the ground connection member 97, the first portion 97A and the second portion 97B may be divided. In this case, the first portion 97A may be changed to a coil shape.

Explanation of Reference Numerals

[0156] 1... Image forming apparatus, 2... Sheet conveying apparatus, 41S... Rotating shaft SH... Sheet, 41... First roller, DF1... Second direction (opposing direction) 42... Second roller, 41S1... First end portion of the rotating shaft 110... First bearing, 120... Second bearing 49R... Biasing means (compression coil spring), 90... Frame F1, F21, F22, F31... Forces for the rotating shaft to move in the first direction (width direction) 41S2... Second end portion of the rotating shaft, 130... Third bearing FR1, FR31... Forces opposite to the forces received by the second bearing from the rotating shaft 123... Restricted portion 41C1, 41C3, 41F1... Protrusions (41C1, 41C3... C-shaped retaining rings, 41F1... Flange) 111... First bearing body, 119... Locking portion, 121... Second bearing body 125... Fitting convex portion, 115... Fitting concave portion, E1... Ground 99... Frame sheet metal, 97, 97S... Ground connection member 98... Shoot sheet metal, 97B... First portion of the ground connection member 97A... Second portion of the ground connection member, 3... Image forming portion 9... Apparatus main body, 80... Drawer, 88... Holding portion, 89... Release portion

Claims

1. A first roller having a rotating shaft extending in a first direction and configured to convey a sheet, a second roller facing the first roller in a second direction orthogonal to the first direction and configured to convey a sheet, a first bearing formed of a conductive resin and supporting a first end portion on one side of the rotating shaft, a second bearing formed of a material having higher toughness than the first bearing and supporting the first end portion, biasing means formed of a conductive material and biasing the first bearing in a direction in which the first roller presses the second roller, a frame supporting the second bearing so as to be movable in the second direction, comprising, the second bearing is configured to receive a force for moving the rotating shaft in the first direction, the frame is configured to restrict movement of the second bearing in the first direction when the rotating shaft receives a force for moving in the first direction. A sheet conveying device characterized by this.

2. further comprising a third bearing formed of a material having higher toughness than the first bearing and supporting a second end portion on the other side of the rotating shaft, the third bearing is configured to receive a force in a direction opposite to the force received by the second bearing from the rotating shaft, the frame is configured to restrict movement of the third bearing in the first direction when the third bearing receives the force in the opposite direction. The sheet conveying device according to claim 1.

3. the second bearing has a restricted portion whose movement in the first direction is restricted by the frame, in the first direction, the first bearing and the restricted portion of the second bearing are in the same position. The sheet conveying device according to claim 1 or 2.

4. the rotating shaft has a protruding portion protruding radially outward from the rotating shaft, the first bearing is positioned between the second bearing and the protruding portion in the first direction, when the rotating shaft moves in the first direction, the protruding portion abuts against the first bearing, the second bearing is configured to receive a force for moving the rotating shaft in the first direction by abutting against the first bearing that abuts against the protruding portion and abutting in the first direction. The sheet conveying device according to claim 1 or 2.

5. the first bearing has a first bearing body into which the first end portion of the rotating shaft is inserted, and a locking portion integrally formed with the first bearing body and configured to lock one end of the biasing means, the second bearing has a second bearing body into which the first end portion of the rotating shaft is inserted, and a restricted portion integrally formed with the second bearing body and configured to have its movement in the first direction restricted by the frame. One of the first bearing body and the second bearing body has a fitting convex portion that protrudes so as to bite into the other of the first bearing body and the second bearing body in the first direction. The other of the first bearing body and the second bearing body has a fitting concave portion that fits with the fitting convex portion to restrict relative rotation around the rotation axis between the first bearing body and the second bearing body. The sheet conveying device according to claim 1 or 2.

6. The biasing means is a compression coil spring formed of a metal wire. A frame sheet metal formed of a metal plate material and connected to the ground. At least one ground connection member formed of a metal wire and contacting the frame sheet metal and the compression coil spring. The sheet conveying device according to claim 1 or 2, further comprising.

7. Further comprising a chute sheet metal formed of a metal plate material and guiding the sheet toward the first roller and the second roller. The ground connection member has a first portion that contacts the chute sheet metal and a second portion that penetrates the frame. The sheet conveying device according to claim 6.

8. The second bearing is formed of a non-conductive resin. The sheet conveying device according to claim 1 or 2.

9. The sheet conveying device according to claim 1 or 2. An image forming unit that forms an image on the sheet. A device body that houses the sheet conveying device and the image forming unit. An image forming apparatus comprising: The image forming unit has a drawer that is movable between a mounting position mounted on the device body and a pulled-out position pulled out from the mounting position. The second roller is rotatably supported by the drawer, and the drawer moves to the pulled-out position to be separated from the first roller. The drawer has a holding portion that holds the second bearing movably in the second direction in a state where the drawer is in the mounting position, and when the drawer starts to move from the mounting position to the pulled-out position, the second bearing is pushed to release the pressing of the first roller against the second roller. An image forming apparatus characterized by having a releasing portion.

Images