Sheet conveying device and image forming apparatus

Abstract

The invention discloses a sheet conveying device and an image forming apparatus. The sheet conveying device includes a frame; a transfer roller unit including a rotatable rotating shaft, a roller contacting the sheet, and a bearing electrically conductive and rotatably supporting the rotating shaft; and a bearing block which fixes the transfer roller unit to the frame by being attached to the bearing. In a sheet conveying device, a bearing seat includes a first member made of a non-conductive resin and a second member made of a conductive resin, and the second member contacts a bearing and a frame.

Description

Technical Field

[0001] This disclosure relates to technologies related to sheet conveying apparatus for conveying sheets, and to technologies related to image forming apparatus for forming images on sheets. Background Technology

[0002] Static electricity is generated at the conveyor rollers of the sheet conveying device due to friction caused by the rotation of, for example, the conveyor rollers. Since the generated static electricity can cause, for example, machine malfunctions or image defects, it is necessary to ground the conveyor rollers to eliminate the static electricity. In Japanese Patent Application Publication No. 2003-95463, the conveyor rollers are grounded by making a conductive bearing contact with a grounded metal. Summary of the Invention

[0003] When attaching a conveyor roller with bearings to a frame, bearing housings made of non-conductive resin are sometimes used. In this case, since the conveyor roller cannot be grounded, machine malfunctions or image defects caused by static electricity may occur. Therefore, this disclosure aims to provide a sheet conveying device and an image forming apparatus that enables the conveyor roller to be reliably grounded to the frame.

[0004] According to one aspect of this disclosure, a sheet conveying device is provided, comprising a frame; a conveying roller unit including a rotatable rotating shaft, a roller that contacts the sheet, and a conductive bearing that rotatably supports the rotating shaft; and a bearing housing that secures the conveying roller unit to the frame by attachment to the bearing. In the sheet conveying device, the bearing housing includes a first member made of non-conductive resin and a second member made of conductive resin, the second member contacting the bearing and the frame.

[0005] The features of this disclosure will become apparent from the following description of embodiments with reference to the accompanying drawings. The following description of embodiments is by way of example. Attached Figure Description

[0006] Figure 1 It is a cross-sectional view of an image forming system.

[0007] Figure 2 This is a perspective view of the transmission unit.

[0008] Figure 3 This is a cross-sectional view of the transmission unit.

[0009] Figure 4 This is a perspective view of a conveyor roller structure.

[0010] Figure 5 This is a schematic diagram of a bearing housing.

[0011] Figure 6A This is a sectional view of the bearing housing.

[0012] Figure 6B This is an enlarged view of the bearing housing.

[0013] Figure 6C This is an enlarged view of the bearing housing.

[0014] Figure 7 This is a perspective view of the upper conveyor unit.

[0015] Figure 8 This is an installation diagram for a conveyor roller.

[0016] Figure 9A The image shows the state before a bearing housing is attached.

[0017] Figure 9B The state after the bearing housing is attached is shown.

[0018] Figure 10A This is a schematic diagram of a support plate with a bearing housing attached.

[0019] Figure 10B The image shows the bearing housing inserted into the support plate.

[0020] Figure 10C The image shows the bearing housing after it has been attached to the support plate. Detailed Implementation

[0021] The present embodiment is described below with reference to the accompanying drawings. It should be noted that since the embodiments described below are preferred embodiments of this disclosure, various technically preferred limitations are added; however, the scope of this disclosure should not be unreasonably limited by the following description. Not all structural features described in this embodiment are essential structural requirements of this disclosure.

[0022] First Embodiment

[0023] Image forming equipment

[0024] In this embodiment, the application of the image forming system in the inkjet recording system 1 is described. Figure 1 This is a schematic diagram illustrating an example of the schematic structure of an inkjet recording system 1. The inkjet recording system 1 is a sheet-fedinkjet recording system that uses two liquids (a reaction liquid and ink) to produce a recording material that forms an ink image on a sheet.

[0025] The inkjet recording system 1 of this embodiment is a combination of an image forming apparatus and multiple sheet conveying devices. Here, devices that are self-supporting due to a chassis (such as casters or adjusters) and are independent of the housing are defined as modules and described.

[0026] The inkjet recording system 1 includes a sheet feed module 1000, a printing module 2000, a drying module 3000, a fixing module 4000, a cooling module 5000, a reversal module 6000, and an ejection stacking module 7000. Paper-cut sheets supplied from the sheet feed module 1000 are conveyed along a transport path, processed by each module, and ejected to the ejection stacking module 7000, which serves as a sheet ejection device.

[0027] As an example of a sheet feeding device, the sheet feeding module 1000 includes repositories 1100a, 1100b, and 1100c for storing sheets. Repositories 1100a, 1100b, and 1100c are configured to be pulled towards the front of the device. At each repository 1100a, 1100b, and 1100c, a sheet is fed one sheet at a time by a separating belt and conveyor rollers (not shown), and the sheet is conveyed to the printing module 2000. It should be noted that although there are three repositories, namely repositories 1100a, 1100b, and 1100c, the number of repositories is not limited to this; it can be one, two, four, or more.

[0028] The printing module 2000 includes an image pre-formation registration and correction unit (not shown), a printing belt unit 2200, and a recording unit 2300. The sheet material conveyed from the sheet feed module 1000 has its tilt and position corrected by the image pre-formation registration and correction unit and is then conveyed to the printing belt unit 2200. The recording unit 2300 is positioned facing the printing belt unit 2200, with the conveying path between them. The recording unit 2300 is a sheet processing unit that performs a recording operation (printing) on ​​the sheet material from above via recording heads. The recording heads are arranged side-by-side along the conveying direction. In this embodiment, a total of five linear recording heads corresponding to four colors—Y (yellow), M (magenta), C (cyan), and Bk (black)—and a reaction liquid are provided. It should be noted that the number of colors and the number of recording heads are not limited to five.

[0029] For inkjet methods, methods using heating elements, piezoelectric elements, electrostatic elements, or MEMS elements can be employed. Ink of the appropriate color is supplied from an ink tank (not shown) to the recording head via corresponding ink tubes. The sheet printed at recording unit 2300 is conveyed by suction from printhead unit 2200, ensuring a gap between the sheet and the recording head. The sheet printed at recording unit 2300 is such that any displacement or color density of the image formed on the sheet is detected by an in-lines scanner (not shown) positioned downstream of recording unit 2300 along the conveying direction. The detection results are used to correct the printed image. In this embodiment, recording unit 2300 is an example of an image forming unit.

[0030] The drying module 3000 includes a decoupling unit 3200, a drying belt unit 3300, and a warm air blowing unit 3400. The drying module 3000 reduces the liquid content in the ink applied to the sheet at the recording unit 2300 of the printing module 2000 and improves the fixing properties between the sheet and the ink. The sheet printed at the recording unit 2300 of the printing module 2000 is conveyed to the decoupling unit 3200 located in the drying module 3000. In the decoupling unit 3200, the sheet can be conveyed due to belt friction and air pressure from above, and sheet displacement on the printing belt unit 2200, which forms the ink image, is prevented by gently holding the sheet on the belt and conveying it. The drying belt unit 3300 is located below the conveyed sheet, and the warm air blowing unit 3400 is located above the conveyed sheet. The drying belt unit 3300 and the warm air blowing unit 3400 are positioned facing each other, with the belt positioned between them.

[0031] The sheet conveyed from the decoupling unit 3200 is conveyed by the drying belt unit 3300 via suction, while simultaneously receiving warm air from the warm air blowing unit 3400, causing the ink to be applied to the surface for drying. It should be noted that, in addition to the method of applying warm air, the drying method can also be a combination of irradiating the sheet surface with electromagnetic waves (such as ultraviolet or infrared rays) and a method of conductive heat transfer through contact with a heating element.

[0032] The fixing module 4000 includes a fixing belt unit 4100. The fixing belt unit 4100 includes an upper belt unit and a lower belt unit, and ink is fixed onto the sheet by passing the sheet between the heated upper belt unit and the lower belt unit.

[0033] The cooling module 5000 includes multiple cooling units 5001 and cools the hot sheet conveyed from the fixing module 4000. Each cooling unit 5001 draws outside air into a cooling chamber via a fan, increasing the pressure within the cooling chamber and causing air blown from nozzles on the conveying guide to impact the sheet, thereby cooling the sheet. The cooling units 5001 are positioned above and below the conveying path and cool both surfaces of the sheet.

[0034] The cooling module 5000 includes a conveyor path switching unit 5200, which can switch between sheet conveyor paths based on when the sheet is conveyed to the reversal module 6000 and when the sheet is conveyed to the duplex conveyor path used in duplex printing. When duplex printing is to be performed, the sheet is conveyed to the conveyor path below the cooling module 5000. In this case, the sheet is further conveyed from the cooling module 5000 along the duplex conveyor path of the fixing module 4000, drying module 3000, printing module 2000, and sheet feed module 1000. The sheet is then conveyed again to the image forming pre-registration correction unit, printing belt unit 2200, and recording unit 2300 of the printing module 2000, and printed again by the recording unit 2300. It should be noted that a first reversal unit 4200 is provided in the duplex conveyor unit of the fixing module 4000 to reverse the front and rear surfaces of the sheet.

[0035] The reversing module 6000 includes a second reversing unit 6400, which can reverse the front and rear surfaces of the conveying sheet and freely change the orientation of the front and rear surfaces of the discharged sheet.

[0036] The discharge stacking module 7000 includes a top tray 7200 and stacking units 7500, and aligns and stacks the sheets conveyed from the reversing module 6000.

[0037] The controller 10 includes a CPU, RAM, and ROM, and controls each part of the inkjet recording system 1. To operate each electrical component with desired timing and required control quantities based on information stored in the ROM or detection signals input from each sensor, the CPU outputs output signals to each electrical component. The ROM and RAM each store information data required to control each part; the CPU reads information data stored in the ROM and writes it into the RAM. It should be noted that in this embodiment, the controller 10 can control an external computer connected to the inkjet recording system 1.

[0038] Structure of the transmission unit

[0039] Figure 2 This is a perspective view showing the structure of the transmission unit 100. Figure 3 This is a cross-sectional view of the conveying unit 100 in a direction perpendicular to the sheet conveying direction when viewed from the upstream side of the sheet conveying direction.

[0040] like Figure 1 As shown, the conveying unit 100 is disposed in the double-sided conveying path below the fixing module 4000. However, since conveying rollers 200 are used at various positions of the conveying sheet in the image forming system, the conveying unit 100 is described as an example.

[0041] The conveying unit 100 includes an upper conveying unit 101 and a lower conveying unit 102, wherein the upper conveying unit 101 includes a conveying roller 200 and the lower conveying unit 102 includes a plurality of driven rollers 300. The conveying roller 200 and the driven rollers 300 form a conveying roller pair, and the sheet is clamped and conveyed by the conveying roller 200 and the driven rollers 300.

[0042] When any sheet being conveyed becomes clogged, the conveying unit 100 can open the sheet conveying path to allow the user to remove the clogged sheet. The lower conveying unit 102 is fixed to the frame of the device body, and the upper conveying unit 101 can rotate upwards relative to the lower conveying unit 102 about a rotation axis on the rear side of the device. It should be noted that in this embodiment, when the conveying unit 100 is attached to the device body, the front side is the side where the user stands to perform the clog removal operation, and the rear side is the side opposite to the side where the user stands to perform the clog removal operation.

[0043] When the upper transmission unit 101 is in the closed state, it is locked by a latch located on the front side, thus preventing it from being opened. Therefore, as... Figure 3 As shown, the conveyor roller 200 and the driven roller 300 are in contact with each other. The driven roller 300 is pushed in, and as a result, the conveyor springs 301, each located on one side of a corresponding driven roller, are compressed, generating a clamping pressure at the conveyor roller 200. In this embodiment, since the conveyor roller 200 is located at the upper conveyor unit 101 and the driven roller 300 is located at the lower conveyor unit 102, a clamping pressure F is applied upward from the driven roller 300 toward the conveyor roller 200.

[0044] It should be noted that although in this embodiment the conveyor roller 200 is disposed on the upper side and the driven roller 300 is disposed on the lower side, this disclosure is not limited thereto. The driven roller 300 may be disposed on the upper side and the conveyor roller 200 may be disposed on the lower side.

[0045] Figure 4 This is a perspective view of a conveyor roller 200. The conveyor roller 200 includes a roller shaft 201, a roller 202, and conductive bearings 203. Conductive bearings 203 are respectively disposed at one of the two ends of the roller shaft 201, and the roller 202 is disposed between the bearings 203 disposed at both ends of the roller shaft 201. The two conductive bearings 203 are bearings that rotatably support the roller shaft 201. The roller 202 and the conductive bearings 203 are press-fitted onto the roller shaft 201. By press-fitting the conductive bearings 203 onto the roller shaft 201, there is no slippage between the roller shaft 201 and the conductive bearings 203, thus suppressing roller shaft scratching due to reduced durability of the roller shaft 201. In other words, by press-fitting the conductive bearings 203 onto the roller shaft 201, a product with high durability can be provided. It should be noted that in this embodiment, the conductive bearings 203 are all examples of bearings.

[0046] Bearing housing structure

[0047] Static electricity is generated at the conveyor rollers of the sheet conveying device due to friction caused by, for example, the rotation of the conveyor rollers. Since the generated static electricity can cause, for example, machine malfunctions or image defects, it is necessary to ground the conveyor rollers to eliminate the static electricity.

[0048] like Figure 4 As shown, when the conductive bearing 203 is press-fitted onto the roller 201 and the integrated conveyor roller 200 is attached to the frame of the conveying unit, it is necessary to adjust the movement of the thrust position of the conveyor roller 200, i.e., the axial position of the conveyor roller. Therefore, a conductive bearing 203 is held in place by a bearing housing, which is fixed to the frame. If a bearing housing made only of general non-conductive resin is used as the bearing housing, grounding cannot be achieved from the side of the conveyor roller 200 mounted on the bearing housing. Therefore, in this embodiment, the bearing housing 400 includes two types of components: a first component 401 made of non-conductive resin and a second component 402 made of conductive resin.

[0049] Figure 5 Figure 6 is a schematic diagram of a bearing housing 400. Figure 7 is a detailed view of the bearing housing 400. Specifically, Figure 6A This is a sectional view of bearing housing 400. Figure 6B and Figure 6C These are magnified views of the bearing housing 400 viewed from different angles. The bearing housing 400 holds one of the conductive bearings 203 of the conveyor roller 200 and adjusts the position of the conveyor roller 200 in the thrust direction (axially upward).

[0050] The bearing housing 400 includes two components: a first component 401 made of ordinary resin and a second component 402 made of conductive resin, which are formed by double molding. It should be noted that the ordinary resin is a non-conductive resin with high resistance, through which current is unlikely to flow. In other words, the bearing housing 400 includes a first component made of non-conductive resin and a second component made of conductive resin. It should be noted that in this embodiment, the conductive resin preferably has a resistance of 100 kΩ or lower. In this embodiment, the bearing housing 400 is configured such that each second component 402 is disposed as a portion of the first component 401, which serves as a base. In other words, the bearing housing 400 is configured such that the proportion of the first component 401 is greater than the proportion of each second component 402. Specifically, the ratio of the surface area of ​​the first component 401 to the surface area of ​​the bearing housing 400 is greater than the ratio of the surface area of ​​each second component 402 to the surface area of ​​the bearing housing 400. This disclosure is not limited thereto; therefore, the ratio of the volume of the first component 401 to the volume of the bearing housing 400 may be greater than the ratio of the volume of each second component 402 to the volume of the bearing housing 400.

[0051] Since conductive resins are generally more fragile than ordinary resins, the overall durability may be reduced if the bearing housing 400 is made solely of conductive resin, or the snap-fit ​​members 403 that hold the corresponding conductive bearing 203, as described below, may be damaged. When considering the possibility of damage to the snap-fit ​​members 403 made of conductive resin, increasing the length of the arms of the snap-fit ​​members 403 can lead to problems such as increased component size or reduced holding force for holding the conductive bearing 203. Therefore, preferably, each snap-fit ​​member 403 that deforms elastically is made of ordinary resin. This reduces the risk of damage to the snap-fit ​​members 403. Because the bearing housing 400 of this embodiment includes a first member 401 made of ordinary resin and each second member 402 made of conductive resin, the bearing housing 400 exhibits excellent durability and conductivity.

[0052] The first component 401 includes a cylindrical portion 408 that faces the circumferential surface of the conductive bearing 203 when the bearing housing 400 is mounted on the conductive bearing 203. The first component 401 also includes a flange 406 projecting radially outward along the conductive bearing 203 and an internal adjusting portion 409 projecting radially inward along the conductive bearing 203. The first component 401 further includes a snap-fit ​​element 403 for retaining the conductive bearing 203, a thrust position adjusting portion 404 for preventing the bearing housing 400 itself from being removed, a rotation adjusting portion 405 for adjusting the rotation of the bearing housing 400, and a handle 407. Each thrust position adjusting portion 404 projects radially outward relative to the cylindrical portion 408. The rotation adjusting portion 405 is provided on the handle 407 and projects in the thrust direction (axially) when the conductive bearing 203 is mounted. Because the snap-fit ​​element 403 retains the conductive bearing 203, the bearing housing 400 can be easily attached and removed. Therefore, the conveyor roller 200 can be easily replaced when a random failure occurs or when periodic replacement is required.

[0053] Each second component 402 is disposed on the cylindrical portion 408 of the bearing housing 400 that holds the conductive bearing 203. For the second component 402 to conduct electricity with the conductive bearing 203 held by the snap-fit ​​engagement 403, each second component 402 needs to be in reliable contact with the conductive bearing 203. Therefore, in this embodiment, the inner diameter of each second component 402 is smaller than the inner diameter of the first component 401. For each second component 402 to reliably contact and conduct electricity with the frame supporting the bearing housing 400, the outer diameter of each second component 402 is larger than the outer diameter of the first component 401.

[0054] It should be noted that the inner and outer diameters of the first component 401 correspond to the inner and outer diameters of the cylindrical portion 408 of the first component.

[0055] Specifically, when mounted on the conductive bearing 203, the distance from the rotation center O of the conductive bearing 203 to the inner diameter portion 402a of each second component 402 is less than the distance from the rotation center O to the inner diameter portion 401a of the first component 401. When mounted on the conductive bearing 203, the distance from the rotation center O of the conductive bearing 203 to the outer diameter portion 402b of each second component 402 is greater than the distance from the rotation center O to the outer diameter portion 401b of the first component 401. In other words, the inner diameter portion 402a of each second component 402 is configured to reliably contact the conductive bearing 203, and the outer diameter portion 402b is configured to reliably contact the grounded frame.

[0056] It should be noted that when the conductive bearing 203 is mounted on the frame, the inner diameter portion 402a and the outer diameter portion 402b of each second component are disposed between the conductive bearing 203 and the frame in the radial direction of the conductive bearing 203. When the bearing housing 400 and the conductive bearing 203 are mounted on the frame, the inner diameter portion 401a and the outer diameter portion 401b of the first component 401 are disposed between the conductive bearing 203 and the frame in the radial direction of the conductive bearing 203.

[0057] In this embodiment, four second members 402 are disposed on the circumference of the bearing housing 400. Since the conveyor roller 200 is used for the positioning of various units conveying sheet material in the image forming apparatus, the angle at which the bearing housing 400 is mounted on the frame depends on various reasons, such as location or space design or the arrangement of other components. Therefore, even if the bearing housing 400 is disposed at any angle, the roller pressure F is applied to each second member 402, and the four second members 402 are disposed on the circumference of the bearing housing 400 to reliably achieve conductivity. In this embodiment, two second members 402 are respectively disposed between two snap-fit ​​members 403 in the circumferential direction of the bearing housing 400. In other words, when the bearing housing 400 is already mounted on the conductive bearing 203, the second members 402 are symmetrically disposed with respect to the rotation center O of the conductive bearing 203 and the straight line of the snap-fit ​​members 403.

[0058] Conductivity is achieved if each second member 402 is positioned at the location where the roll pressure F is applied by the conveyor roller 200. Therefore, one or more second members 402 are positioned on the semi-circular side that receives the roll pressure when the conveyor roller 200 conveys the sheet. That is, preferably, when viewed from the direction of the rotation axis of the conveyor roller 200, the rotation center of each second member 402 relative to the roller shaft 201 is located on the side opposite to the clamping portion of the conveyor roller 200. In this embodiment, since the conveyor roller 200 applies the roll pressure F from below, at least one or more second members 402 need to be provided on the semi-circular side above the bearing housing 400 when the bearing housing 400 is installed. However, the arrangement, number, or size of the second members 402 can be suitably determined.

[0059] Upper conveyor structure

[0060] Figure 7 This is a perspective view of the upper conveying unit 101. The upper conveying unit 101 supporting the conveying roller 200 includes a front support plate 501, a rear support plate 502, a support plate 503 extending between the front support plate 501 and the rear support plate 502, the conveying roller 200, and a bearing housing 400. It should be noted that the front support plate 501, the rear support plate 502, and the support plate 503 are all examples of frames formed of metal plates and in contact with a grounded structure. In other words, the frame is grounded. In this embodiment, the rear support plate 502 is an example of a side plate.

[0061] The conductive bearing 203 on the front side of the conveyor roller 200 is supported by the front support plate 501.

[0062] The conductive bearing 203 on the back of the conveyor roller 200 is supported by the rear support plate 502 via the bearing housing 400. Due to the rotation of the conductive bearings 203 on both sides, the conveyor roller 200 can rotate freely.

[0063] It should be noted that in this embodiment, although the bearing housing 400 is mounted on the conductive bearing 203 on the rear side of the conveyor roller 200, the bearing housing 400 is not mounted on the conductive bearing 203 on the front side of the conveyor roller 200. In other words, although the bearing housing 400 is mounted on the conductive bearing 203 located at one end of the conveyor roller 200, the bearing housing 400 is not mounted on the conductive bearing 203 located at the other end of the conveyor roller 200. Since the conductive bearings 203 on the front side are in contact with the front support plate 501 due to the clamping pressure F from the driven roller 300, they are grounded without the bearing housing 400. That is, in this embodiment, the conveyor roller 200 is grounded in two locations, namely, on the rear side and the front side. Specifically, the conductive bearings 203 on the front side are grounded by the front support plate 501 due to the clamping pressure, and the conductive bearings 203 on the rear side are grounded by the rear support plate 502 through the second member 402 made of conductive resin of the bearing housing 400. In this way, by setting the bearing housing 400 only on one end of the conveyor roller 200, the number of components can be reduced.

[0064] However, the bearing housing 400 may not be mounted on the conductive bearing 203 on the rear side of the conveyor roller 200, but instead may be mounted on the conductive bearing 203 on the front side of the conveyor roller 200. Alternatively, the bearing housing 400 may be mounted on both the conductive bearing 203 on the front side and the conductive bearing 203 on the rear side of the conveyor roller 200. However, as described below, in order to adjust the axial thrust position of the conveyor roller 200, it is necessary to mount the bearing housing 400 on at least one side of the conveyor roller 200.

[0065] Figure 8 Figure 9 is an explanatory diagram of attaching a conveyor roller 200 to the upper conveyor unit 101. Figures 10 and 10 are explanatory diagrams of attaching a bearing housing 400, respectively. Figure 9A The image shows the state of the bearing housing 400 before it is attached to a conductive bearing 203. Figure 9B The state of the bearing housing 400 after it is attached to the conductive bearing 203 is shown.

[0066] Figure 10A The conveyor roller attachment portion 504 of the rear support plate 502 is shown. Figure 10B A bearing housing 400 is shown inserted into a conveyor roller attachment 504. Figure 10C The attached bearing housing 400 is shown.

[0067] Figure 8 The upper conveying unit 101 is shown as viewed from the rear. The front support plate 501 has an opening 505. The rear support plate 502 includes a conveyor roller attachment portion 504, which is an opening portion. It should be noted that after the conveyor roller 200 is attached to the frame, when viewed from the sheet conveying direction, the conductive bearing 203 on the front side of the conveyor roller 200 is configured to overlap with the front support plate 501.

[0068] After the conveyor roller 200 is attached to the frame, when viewed from the sheet conveying direction, the conductive bearing 203 and bearing housing 400 on the back of the conveyor roller 200 are arranged to overlap with the rear support plate 502. However, since the bearing housing 400 is also provided at the conveyor roller attachment portion 504 in addition to the conductive bearing 203, the size of the conveyor roller attachment portion 504 is larger than the size of the opening portion 505.

[0069] like Figure 8 As shown, when installing the conveyor roller 200, the conveyor roller 200 is placed on the conveyor roller attachment portion 504 of the front support plate 501 and the rear support plate 502, and the bearing seat 400 is attached to the conductive bearing 203 on the rear side. Figure 8 (The arrow in the figure). At this time, as shown in FIG9, the bearing housing 400 is fixed to the conductive bearing 203 from the rear side, and the conductive bearing 203 is held by the snap-fit ​​engagement 403 of the bearing housing 400. In this embodiment, since the snap-fit ​​engagement 403 of the bearing housing 400 holds the conductive bearing 203, tools such as actuators are not required, and the conductive bearing 203 can be easily attached to and removed from the bearing housing 400. It should be noted that in this embodiment, the conductive bearing 203 is a flangeless conductive bearing. When the bearing housing 400 is attached to the conductive bearing 203, the internal adjustment part 409 contacts the side surface of the conductive bearing 203. Therefore, the conductive bearing 203 is held without penetrating the bearing housing 400. Figure 5 ).

[0070] Figure 10 shows the conveyor roller attachment 504 as viewed from the rear side of the upper conveyor unit 101. Figure 8 (The arrow in the image). Figure 10A As shown, the conveyor roller attachment portion 504 includes a circular portion 504a, an open portion 504b, and a positioning portion 504c, wherein the cylindrical portion 408 of the bearing housing 400 is inserted into the circular portion 504a, the thrust position adjustment portion 404 is inserted into the open portion 504b, and the rotation adjustment portion 405 is inserted into the positioning portion 504c. Figure 10B As shown, after the bearing housing 400 is attached to the conductive bearing 203, the thrust position adjustment part 404 of the bearing housing 400 is aligned with the position of the opening part 504b to insert the bearing housing 400 into the rear support plate 50. Thereafter, as... Figure 10CAs shown, the rotating bearing housing 400 is rotated, and the rotation adjustment part 405 is fixed to the positioning part 504c. Therefore, since the thrust position adjustment part 404 and the rotation adjustment part 405 are held in place by the rear support plate 502, and the bearing housing 400 no longer detaches from the rear support plate 502, the axial thrust position of the conveyor roller 200 is determined. It should be noted that the rotation adjustment part 405 is located at the center of the annular handle 407, extends from the flange 406, and can be easily inserted into the rear support plate 502 by the user. When the conveyor roller 200 needs to be replaced or removed, it can be easily replaced by performing the above operations in reverse order.

[0071] It should be noted that the flange 406 of the bearing housing 400 protrudes in the radial direction of the bearing housing 400, and the outer diameter of the flange 406 is larger than the outer diameter of the circular portion 504a of the conveyor roller attachment portion 504. It should also be noted that the shape of each thrust position adjustment portion 404 of the bearing housing 400 is smaller than the shape of each opening portion 504b of the conveyor roller attachment portion 504. In this embodiment, the circular portion 504a is an example of a first opening portion, and each opening portion 504b is an example of a second opening portion. It should be noted that after positioning the thrust position of the bearing housing 400 ( Figure 10C Each thrust position adjustment part 404 is located inside the rear support plate 502, and the flange 406 is located outside the rear support plate 502. In other words, the axial position of the conveyor roller 200 is adjusted by inserting the rear support plate 502 between the thrust position adjustment part 404 and the flange 406 of the bearing seat 400. In this embodiment, each thrust position adjustment part 404 is an example of a first protrusion, and the flange 406 is an example of a second protrusion.

[0072] Due to the aforementioned structure, the conveyor roller 200 can be reliably and stably grounded to the front support plate 501 and the rear support plate 502 via the conductive bearing 203 and the bearing housing 400. It should be noted that the front support plate 501 and the rear support plate 502 are grounded. Therefore, a conveyor roller structure can be provided that suppresses malfunctions caused by static electricity generated by the rotational friction of the conveyor roller 200, and exhibits excellent durability and maintainability.

[0073] It should be noted that although the above embodiments have described the application of the image forming system to the inkjet recording system 1 using the inkjet recording method, the image forming system is not limited thereto and can be applied to the image forming system using the electrophotographic method.

[0074] According to this disclosure, a sheet conveying device and an image forming apparatus may be provided, which are capable of reliably grounding the conveying rollers to a frame.

[0075] While this disclosure has been described with reference to embodiments, it should be understood that this disclosure is not limited to the disclosed embodiments. The scope of the following claims should be given the broadest interpretation to cover all such modifications and equivalent structures and functions.

Claims

1. A sheet conveying device, the sheet conveying device comprising: frame; The conveyor roller unit includes a rotatable rotating shaft, a roller that contacts the sheet, and a conductive bearing that rotatably supports the rotating shaft. as well as A bearing housing, which secures the conveyor roller unit to the frame by attaching it to the bearing. The bearing housing includes a first component made of non-conductive resin and a second component made of conductive resin, and The second component contacts the bearing and the frame.

2. The sheet conveying device according to claim 1, in, At the location where the bearing is arranged axially. The distance from the bearing's rotation center to the inner diameter of the second component that contacts the bearing's outer diameter is less than the distance from the bearing's rotation center to the inner diameter of the cylindrical portion of the first component. The distance from the rotation center of the bearing to the outer diameter portion of the second component that contacts the frame is greater than the distance from the rotation center of the bearing to the outer diameter portion of the cylindrical portion of the first component.

3. The sheet conveying device according to claim 1, in, The ratio of the surface area of ​​the first component to the surface area of ​​the bearing housing is greater than the ratio of the surface area of ​​the second component to the surface area of ​​the bearing housing.

4. The sheet conveying device according to claim 1, in, The contact area between the first component of the bearing housing and the bearing is greater than the contact area between the second component of the bearing housing and the bearing.

5. The sheet conveying device according to claim 1, further comprising: The driven roller unit is positioned facing the conveyor roller unit and together with the conveyor roller unit forms a clamping part. The driven roller unit is pushed toward the conveyor roller unit by a spring.

6. The sheet conveying device according to claim 5, in, When viewed from the direction of the rotation axis of the conveyor roller unit, the rotation center of the second component relative to the rotation axis is located on the side opposite to the clamping part.

7. The sheet conveying device according to claim 6, in, The bearing housing includes a plurality of the second components.

8. The sheet conveying device according to claim 1, in, The conveyor roller unit includes two bearings, which are respectively disposed at both ends of the rotating shaft. The bearing at one end of the rotating shaft has a bearing housing mounted thereon, and The bearing at one end of the rotating shaft does not have a bearing housing mounted on it.

9. The sheet conveying device according to claim 1, in, The bearing housing includes a snap-fit ​​component for retaining the bearing, and The first component includes the snap-fit ​​part.

10. The sheet conveying device according to claim 1, in, The bearing housing includes a first protrusion and a second protrusion projecting radially outwards, and the first protrusion and the second protrusion are disposed at different positions axially. The position of the conveyor roller unit in the axial direction is adjusted by inserting the frame between the first protrusion and the second protrusion in the axial direction.

11. The sheet conveying device according to claim 10, in, The bearing housing includes a rotation adjustment part for adjusting the rotation of the bearing housing, and The rotation adjustment part can be fixed at a position reached by rotating from the position where the first protrusion has been inserted into the opening of the frame.

12. The sheet conveying device according to claim 1, in, The bearing is press-fitted onto the rotating shaft.

13. An image forming apparatus, the image forming apparatus comprising: The sheet conveying device according to claim 1; as well as An image forming unit that forms an image on a sheet.

14. A bearing housing, the bearing housing comprising: The first component is made of non-conductive resin, and the second component is made of conductive resin. The bearing housing is configured to secure the conveyor roller unit to the frame. The conveyor roller unit includes a rotatable rotating shaft and a conductive bearing that rotatably supports the rotating shaft. The second component is configured to contact the bearing and the frame.

Images