JP7438798B2 - Sheet conveyance device, image forming device - Google Patents

Description

The present invention relates to a sheet conveying device that conveys sheets, and an image forming apparatus equipped with the same.

Conventionally, some image forming apparatuses such as printers that form images on sheets are equipped with a sheet conveying device that conveys irregularly shaped sheets such as postcards and long papers, and special sheets such as OHP films and envelopes into the inside of the apparatus body. . In such a sheet conveying device, the sheet is conveyed by sandwiching the sheet between a pair of rotating rollers and sequentially passing the sheet. Further, as a drive mechanism for rotating the roller pair, a configuration is used in which the drive of a motor is transmitted by a timing belt to a pulley to which the shaft of the roller pair is fixed to convey the sheet. As such a drive mechanism, Patent Document 1 provides a shape in which a housing integrated with a one-way clutch can be placed inside the pulley, and a shape in which a timing belt can be slidably connected to the outer peripheral surface of the pulley, and the drive mechanism is provided with a shape that allows a housing integrated with a one-way clutch to be placed inside the pulley, and a shape that allows a timing belt to be slidably connected to the outer peripheral surface of the pulley. A configuration for conveying sheets is disclosed.

Japanese Patent Application Publication No. 6-107346

In Patent Document 1, it is necessary to mold a dedicated pulley that can hold the one-way clutch and the housing inside the pulley, which causes high costs. Here, in order to realize low cost, a configuration will be considered in which the pulley and the one-way clutch are connected using a member for connecting the one-way clutch to the pulley. In this case, since the one-way clutch is attached to the flange-shaped portion of the pulley, there is a problem that the thickness of the drive mechanism in the axial direction increases by the flange-shaped portion.

The present invention has been made to solve the above problems, and an object of the present invention is to achieve both cost reduction and space saving when conveying sheets using a pulley equipped with a one-way clutch. do.

In order to solve the above problems, one aspect of the present invention provides a sheet conveyance device and an image forming apparatus including the same, which includes a shaft, a rotating body rotatable around the shaft, and a nip portion for conveying the sheet. an opposing member formed together with the rotary body, a sheet conveying means configured to rotate the rotary body in a first direction and convey the sheet held between the nip portions, a rotational drive means, and the rotational drive means. a belt that rotates by a rotational drive of a belt; a hole into which the shaft can be inserted; a circumferential surface over which the belt is stretched; and regulating the axial position of the shaft of the belt stretched over the circumferential surface. a pulley that rotates as the belt rotates, the pulley having a first flange portion provided in one axial direction and an engaged portion opening toward the other axial direction; The rotation of the pulley is transmitted to the shaft to rotate the rotary body in the first direction, and the rotational drive speed of the rotary body in the first direction is higher than the rotational drive speed of the rotary drive means in the first direction. a one-way clutch that allows rotation of the rotating body at a high rotational speed; a housing portion that accommodates the one-way clutch at a position different from the pulley in the axial direction; and a housing portion that is engageable with the engaged portion. The belt includes an engaging portion and a second flange portion that can regulate the position of the belt that is stretched over the circumferential surface in the axial direction in a state where the engaging portion and the engaged portion are engaged. and a connecting member that connects the pulley and the one-way clutch.

According to the present invention, when conveying a sheet using a pulley provided with a one-way clutch, it is possible to achieve both cost reduction and space saving.

1 is a schematic configuration diagram of an image forming apparatus according to a first embodiment of the present disclosure. 1 is a schematic perspective view of a sheet conveying device according to a first embodiment. 3A and 3B are diagrams (A, B) showing the configuration of the housing of Example 1. FIG. FIG. 3(C) is a diagram showing the configuration of a pulley in Example 1. Figures (A, B) showing the configuration when the pulley and housing of Example 1 are connected. The figure which illustrated the pulley when a one-way clutch is not attached.

Hereinafter, exemplary embodiments for carrying out the present invention will be described with reference to the drawings.

<Example 1>
FIG. 1 is a schematic cross-sectional view of an image forming apparatus 100 that includes a manual sheet feeding section 40 according to a first embodiment and also functions as a sheet conveying device. The image forming apparatus 100 is an intermediate transfer tandem type printer in which image forming units PY, PM, PC, and PK are arranged side by side with respect to an intermediate transfer belt 506. Note that this embodiment can also be applied to a printer having a configuration other than an electrophotographic method, such as an inkjet method, or a printer that performs monochrome printing.

<Image formation process>
A series of image forming processes for forming an image on a sheet in the image forming apparatus 100 will be described together with the configuration of each part of the image forming apparatus 100. Image forming units PY, PM, PC, and PK serving as image forming means in this embodiment are electrophotographic units having photoreceptors 1Y, 1M, 1C, and 1K, respectively. Further, the image forming units PY, PM, PC, and PK form yellow (Y), magenta (M), cyan (C), and black (K) toner images, respectively. The image forming units PY, PM, PC, and PK have a common configuration except that the toner colors used in the development process are different. Therefore, in this embodiment, the configuration of the image forming section and the series of image forming processes will be explained using the image forming section PY as an example, and the explanation of the image forming sections PM, PC, and PK will be omitted. The image forming unit PY includes a photoreceptor 1Y, an exposure device 511, a developing device 510, a primary transfer device 507, and a photoreceptor cleaner 509. The photoreceptor 1Y rotates in the direction of arrow A in FIG. 1 with its surface uniformly charged by charging means in advance. Light is irradiated onto the charged photoreceptor 1Y from the exposure device 511 based on a signal of image information sent from an external device connected to the image forming apparatus 100, and the light passes through the diffraction means 512 and the like. An electrostatic latent image is formed on the surface of the photoreceptor 1Y. Toner development is performed by the developing device 510 on the electrostatic latent image formed on the surface of the photoreceptor 1Y, and a toner image is formed on the surface of the photoreceptor 1Y. Thereafter, a predetermined pressing force and transfer bias are applied to the toner image on the surface of the photoreceptor 1Y by the primary transfer device 507, and the toner image is transferred onto the intermediate transfer belt 506. Thereafter, the transfer residual toner remaining on the photoreceptor 1Y is collected by the photoreceptor cleaner 509 and prepared for the next image formation. In the image forming units PM, PC, and PK, toner images of each color are formed similarly to the image forming unit PY, and the toner images are transferred onto the intermediate transfer belt 506.

<Sheet feeding from sheet cassette>
The image forming apparatus 100 includes a sheet feeding section 51 that can be inserted and removed from the main body of the image forming apparatus 100, a sheet cassette 52 that stores sheets S in the sheet feeding section 51, and a sheet cassette 52 that feeds the sheets S stored in the sheet cassette 52. It has an air feeding head section 53 for feeding the air. The sheet cassette 52 stores sheets S of a standard size, such as A4 size, for example. The sheets stored in the sheet cassette 52 are attracted to the conveyor belt and fed by a suction fan (not shown) of the air feeding head section 53 in accordance with the image forming timing. The sheet S separated into single sheets and sent out by the air feeding head section 53 is transported inside the main body of the image forming apparatus 100 by the transport section 54. The sheet S passes through the conveyance section 50 and undergoes skew correction in the skew correction section 55 . Further, the registration roller pair 7 performs so-called timing correction to convey the sheet S in accordance with the toner image on the intermediate transfer belt 506. Specifically, first, the registration roller pair 7 transports the sheet S while the transport speed is temporarily increased. Then, when the leading edge of the sheet S passes the detection position of the sheet detection sensor 8 and the leading edge of the sheet S is detected by the sheet detection sensor 8, the registration roller pair 7 decelerates the conveyance speed of the sheet S and conveys the sheet S. do. In this way, in the conveyance section from the registration roller pair 7 to the secondary transfer section, the conveyance speed of the sheet S is controlled to be accelerated or decelerated in accordance with the toner image on the intermediate transfer belt 506, and timing correction is performed. Further, when the sheet S is being conveyed by the registration roller pair 7, acceleration/deceleration control of the drive motor is performed so as to synchronize the conveyance speed of the sheet S by the other conveyance roller pairs that sandwich the sheet S. The sheet S held between the registration roller pair 7 is conveyed to a transfer nip portion 66P formed by a secondary transfer inner roller 503 and a secondary transfer outer roller 56, which is a secondary transfer portion, and toner is applied to the sheet S. The image is transferred. The sheet S onto which the toner image has been transferred is transported by a pre-fixing sheet transport device 57 to a fixing device 58, where a predetermined pressing force and a heating effect by a heater or the like are applied, so that the toner is melted and fixed. As a result, the toner is fixed on the sheet S. The sheet S with the toner fixed thereon is discharged onto the discharge tray 500 by the branching conveyance device 59 . Furthermore, when images need to be formed on both sides of the sheet S, the sheet S is reversed by the reversing conveyance device 501 and conveyed toward the double-sided conveyance device 502 . The sheet S conveyed to the double-sided conveyance device 502 is conveyed again toward the transfer nip portion 66P, and an image is formed on the back side in the same way as the image formation on the front side.

<Sheet feeding from the manual feeding section>
Next, the configuration of the manual sheet feeding section 40 will be described with reference to FIGS. 1 and 2. FIG. 2 is a schematic perspective view of the manual sheet feeding section 40. The manual sheet feeding section 40 includes a manual feeding tray 41 , a pair of feeding rollers 42 , a pair of first conveying rollers 46 , and a drive motor 78 . The manual feed tray 41 as a sheet support unit of this embodiment has a support surface that supports the sheet S, and is configured such that the support surface can be opened and closed with respect to the main body of the image forming apparatus 100. The feeding roller pair 42 is arranged so as to be able to contact the feeding roller 42a, which is disposed upstream of the first feeding roller pair 46 in the feeding direction of the sheet S, and is arranged so as to be able to contact the feeding roller 42a. and a separation roller 42b that is rotatable following the rotation. The feeding roller pair 42 is capable of feeding the sheet S using a frictional separation method, and feeds the sheet S supported by the manual feed tray 41 in accordance with the image forming timing of the image forming apparatus 100. Specifically, the feeding roller pair 42 picks up the sheet S supported on the manual feed tray 41 with the feeding roller 42a, separates the picked up sheets S one by one with the separating roller 42b, and transfers the sheets S to the first feeding roller pair 46. to be sent to.

At the timing when the leading edge of the sheet S is nipped in the nip portion N of the first pair of conveying rollers 46, the feeding roller pair 42 is freed by cutting off the drive transmission of the driving means (not shown) that rotates the feeding roller pair 42. It becomes possible to rotate. Note that the driving means (not shown) for the pair of feeding rollers 42 includes, for example, a partially toothed gear that rotates when a solenoid is turned on after the driving motor 78 starts rotating, and the drive is transmitted to the feeding roller 42a. configuration can be used. In such a configuration, the partially toothed gear cuts off the drive from the drive motor 78 after one rotation, so that the sheets S supported on the manual tray 41 are separated and fed one by one by the feeding roller pair 42. I can do it.

The sheet S fed by the feeding roller pair 42 is delivered to the first conveying roller pair 46. The first conveying roller pair 46 as a sheet conveying means in this embodiment includes a conveying roller 46a as a rotating body in this embodiment, and a driven roller 46b that rotates following the rotation of the conveying roller 46a. The conveyance roller 46a forms a nip portion N with the driven roller 46b as an opposing member in this embodiment, rotates with the sheet S sandwiched in the nip portion N, and directs the sheet S toward the internal conveyance roller pair 60. transport.

Next, a configuration for rotating the first conveying roller pair 46 will be described. A timing belt 74, which is a belt in this embodiment, is stretched around the circumferential surface of a pulley 78a of a drive motor 78, which is a rotational drive means in this embodiment. The timing belt 74 spans the circumferential surface of the pulley 78a and the circumferential surface 72b of the pulley 72. When the timing belt 74 rotates due to the rotational drive of the drive motor 78, the rotation of the timing belt 74 causes the pulley 72 to rotate. It also rotates. Furthermore, in this embodiment, as shown in FIG. 2, a tensioner 73 is disposed between the drive motor 78 and the pulley 72 on the rotational trajectory of the timing belt 74. A tensioner 73 serving as a tension applying mechanism in this embodiment applies tension to a timing belt 74. Further, in this embodiment, a housing 75 is attached to the pulley 72 in which a one-way clutch 77 that transmits the rotation of the pulley 72 in the direction of arrow RT in FIG. 2 to the shaft 71 is housed. Since the conveyance roller 46a is rotatable around the shaft 71, when the rotation of the pulley 72 in the direction of arrow RT in FIG. 2 is transmitted to the shaft 71 by the one-way clutch 77, the rotation of the shaft 71 causes Rotate in the direction of arrow RT. The driven roller 46b rotates as the transport roller 46a rotates, and the sheet S sandwiched in the nip portion N is disposed downstream of the transport roller pair 46 in the transport direction FD. 61. The arrow RT direction in FIG. 2 is an example of the first direction in this embodiment, and the first direction in this embodiment is when the sheet S is transported from upstream to downstream in the transport direction FD. This is the rotation direction of the conveyance roller 46a.

Then, the sheet S transported by the first transport roller pair 46 is sequentially delivered to the internal transport roller pair 60 and 61 inside the main body of the image forming apparatus 100, and is transported to the transport section 50. The sheet S that has passed through the conveyance section 50 is conveyed to the skew correction section 55, and the skew correction section 55 performs skew correction. The sheet S that has passed through the skew correction section 55 is subjected to timing correction by the registration roller pair 7, and is conveyed to the transfer nip section 66P, where the toner image is transferred onto the sheet S. The operations after the toner transfer are the same as those when the sheet S is fed from the sheet feeding section 51, so a redundant explanation will be omitted. Note that the conveying roller pair 46 is the first sheet conveying means in this embodiment. In addition, roller pairs downstream of the conveyance roller pair 46 in the conveyance direction FD of the sheet S, such as the internal conveyance roller pair 60 and 61, the registration roller pair 7, the conveyance section 50, and the skew correction section 55 in this embodiment This is an example of a second sheet conveying means.

Here, the relationship between the behavior of the first conveying roller pair 46 and the one-way clutch 77 when a long sheet is fed from the manual sheet feeding section 40 will be described. Note that the long sheet refers to a sheet whose length in the conveyance direction FD is longer than the sheet that can be stored in the sheet cassette 52. When a long sheet is fed from the manual sheet feeding section 40, before the rear end of the long sheet passes through the nip portion N of the first conveying roller pair 46, the leading end of the long sheet passes through the registration roller. It can reach 7 vs. In this embodiment, the one-way clutch 77 transmits the rotation of the pulley 72 to the shaft 71 to rotate the conveyance roller 46a. As a result, the one-way clutch 77 allows the conveyance roller 46a to rotate in a state where the rotational speed of the conveyance roller 46a is higher than the rotational speed of the drive motor 78. In other words, even if the rotation speed of the drive motor 78 is faster than the rotation speed of the first transport roller pair 46, the pulley 72 rotates in the opposite direction of the arrow RT direction in FIG. 2 due to the action of the one-way clutch 77. Never. As a result, even if the rotational speed of the first conveyance roller pair 46 becomes faster than the rotational drive speed of the drive motor 78, the rotation of the conveyance roller 46a is not hindered. A situation in which the rotational speed of the first conveying roller pair 46 becomes faster than the rotational driving speed of the drive motor 78 is when the long sheet is held between the first conveying roller pair 46 and the registration roller pair 7, and the registration roller A case can be considered in which the rotational speed of pair 7 is increased. As described above, in this embodiment, even if the rotational speed of the registration roller pair 7 becomes faster than the rotational speed of the first conveyance roller pair 46, the first conveyance roller pair 46 can be rotated. This makes it possible to transport long sheets to. Therefore, when timing correction is performed by the registration roller pair 7 while the rear end of the long sheet is held between the conveyance rollers 46a, vibration of the timing belt 74 can be suppressed, and the timing belt 74 can be prevented from falling off from the pulley 72. can be suppressed.

By the way, in a configuration in which a pulley and a one-way clutch are used as a drive mechanism to rotate a pair of rollers to convey a sheet, a radial load is applied to the pulley due to the tension of the timing belt, which affects the operation of the one-way clutch. Sometimes. On the other hand, there is one in which a one-way clutch is disposed inside a pulley that is provided to the shaft via a bearing, thereby reducing the influence of the radial load on the one-way clutch, thereby making it possible to convey the sheet. In this case, while it is possible to reduce the radial load on the one-way clutch, it is necessary to provide the pulley with a shape for arranging the one-way clutch. As a result, a special pulley must be molded according to the shape of the one-way clutch, resulting in increased costs.

Further, a configuration in which the pulley and the one-way clutch are connected using a member that connects the one-way clutch to the pulley as a drive mechanism for rotating the roller pair will be considered. When power from a motor is transmitted to a pulley by a belt, the pulley rotates as a result of the rotation of the belt that spans the circumferential surface of the pulley. Therefore, the pulley is provided with a flange-shaped portion for the purpose of preventing the belt from falling off in the axial direction. However, when connecting the one-way clutch to the pulley, it is necessary to attach a member for connecting the one-way clutch to the flange-shaped portion of the pulley and connect the one-way clutch to the attached member. In such a configuration, the thickness of the pulley and one-way clutch in the axial direction increases by the thickness of the flange-shaped portion of the pulley, and it is necessary to secure a wide clearance for disposing the drive mechanism inside the image forming apparatus 100. There is.

On the other hand, in the present embodiment, the position of the timing belt 74 that spans the pulley 72 in the axial direction AX can be regulated by the housing 75 as a connecting member that connects the pulley 72 and the one-way clutch 77. Note that the axial direction AX is a direction along the axis of the shaft 71 (for example, a direction parallel to the axis of the shaft 71). Next, the shape of the housing 75 that connects the pulley 72 and the one-way clutch 77 of this embodiment and the state of connection between the pulley 72 and the one-way clutch 77 will be described. FIG. 3 is a diagram illustrating a state before the pulley 72 and one-way clutch 77 are connected, and FIG. 3(A) is a side perspective view of the housing 75 in a state in which the one-way clutch 77 is housed. FIG. 3(B) is a side perspective view of the housing 75 in which the one-way clutch 77 is housed. FIG. 3(C) is a top perspective view of the pulley 72 with the shaft 71 inserted. FIG. 4 is a diagram illustrating the connected state of the pulley 72 and the one-way clutch 77, and FIG. 4(A) is a perspective view showing the pulley 72 and the one-way clutch 77 in the connected state. FIG. 4(B) is a sectional view showing the pulley 72 and one-way clutch 77 in a connected state.

As shown in FIG. 3A, when viewed in the direction from a to a' in the axial direction AX, the housing 75 is provided with an accommodating portion 75a that accommodates the one-way clutch 77 and a flange shape 75b. ing. Further, as shown in FIG. 3B, when viewed from a′ to a in the axial direction AX, the housing 75 has a side opposite to the housing portion 75a via the flange shape 75b in the axial direction AX. An engaging portion 75c is provided. That is, the housing 75 is provided with a housing portion 75a on one side in the axial direction AX (for example, the a side in the axial direction AX) and an engaging portion 75c on the other side (for example, on the a′ side in the axial direction AX). . The accommodating portion 75a is capable of accommodating the one-way clutch 77 and is formed in a shape capable of engaging with the outer race of the one-way clutch 77. The flange shape 75b serving as the second flange portion of this embodiment is formed to have an insertion portion 75d in the center into which the shaft 71 (see FIG. 4(B)) can be inserted. As shown in FIG. 3(C), the pulley 72 has a hole 72a into which the shaft 71 can be inserted, a circumferential surface 72b over which the timing belt 74 (see FIG. 2) is passed, and a flange as a first flange. It has a shape 72c and an engaged portion 72d that can be engaged with the engaging portion 75c. As shown in FIG. 3C, when viewed from a to a' in the axial direction AX, the pulley 72 is provided with a flange shape 72c on one side in the axial direction AX. The engaged portion 72d is located on a side surface of the pulley 72 (e.g., on the axial It opens toward the side surface on the a side in the direction AX). Further, the engaged portion 72d extends radially from the hole 72a in the radial direction of the circumferential surface 72b and opens, for example, as shown in FIG. 3(C), and is recessed from the opening in the direction along the axial direction AX. These are oval-shaped kerf grooves 72d1 and 72d2. That is, the pulley 72 is provided with a flange shape 72c on one side in the axial direction AX, and an engaged portion 72d that is open toward the other side in the axial direction AX.

Further, the engaging portion 75c is, for example, as shown in FIG. 3(B), protrusions 75c1 and 75c2 protruding from the flange shape 75b, and protruding in the direction from a to a' in the axial direction AX. The protrusion 75c1 has a shape that can be fitted into the cut groove 72d1, and the protrusion 75c2 can fit into the cut groove 72d2. As the protrusion 75c1 and the cut groove 72d1 and the protrusion 75c2 and the cut groove 72d2 fit together from a to a' in the axial direction AX, the one-way clutch 77 causes the pulley 72 to rotate toward the shaft 71. Transmission becomes possible. That is, the direction in which the engaging portion 75c is inserted into the engaged portion 72d of the pulley 72 is the direction along the axial direction AX, for example, the direction from a to a′ in the axial direction AX in FIG. 4(A). It is. When the protrusion 75c1 and the cut groove 72d1 and the protrusion 75c2 and the cut groove 72d2 are respectively fitted, the one-way clutch 77 causes the conveyance in a state where the rotational speed of the conveyance roller 46a is higher than the rotational drive speed of the drive motor 78. Rotation of the roller 46a is allowed.

Note that the shape of the engaging portion 75c shown in FIG. 3(B) and the shape of the engaged portion 72d shown in FIG. 3(C) are shapes other than those shown in FIG. 3(B) and FIG. 3(C). You can also use it as For example, as another example, three or more grooves extending radially from the hole 72a in the radial direction of the circumferential surface 72b may be provided as the engaged portion 72d. In this case, the shape of the engaging portion 75c is such that it can fit into three or more grooves extending radially from the hole 72a in the radial direction of the circumferential surface 72b. Further, as another example of the shape of the engaged portion 72d, it may have a shape extending radially from the hole 72a in the radial direction of the circumferential surface 72b (for example, recesses 72d3 and 72d4 shown in FIG. 3(C)). . In this case, it is preferable that the engaging portion 75c has a shape that can fit into the recesses 72d3 and 72d4.

When the engaging portion 75c of the housing 75 in which the one-way clutch 77 is housed is engaged with the engaged portion 72d of the pulley 72, the pulley 72 and the one-way clutch 77 are engaged with the housing 75, as shown in FIG. 4(A). It becomes connected by . At this time, the position of the timing belt 74 in the axial direction AX of the shaft 71 can be regulated by the flange shape 72c and the flange shape 75b. Specifically, as shown in FIG. 4(A), when the engaging portion 75c and the engaged portion 72d are engaged, the position of the timing belt 74 extending over the circumferential surface 72b in the axial direction AX is can be controlled by the flange shape 72c and the flange shape 75b. Further, as shown in FIG. 4(B), in a state where the pulley 72 and the one-way clutch 77 are connected by the housing 75, the one-way clutch 77 is arranged at a different position from the pulley 72 in the axial direction AX. This is due to the shape of the accommodating part 75a. For example, as shown in FIG. The shape is such that a one-way clutch 77 can be accommodated therein. When the housing portion 75a has this shape, the one-way clutch 77 can be housed at a position different from the pulley 72 in the axial direction AX. In this way, when the one-way clutch 77 and the pulley 72 are connected using the housing 75, the load in the radial direction due to the rotation of the timing belt 74 is applied to the pulley 72 and the shaft 71. Further, by connecting the one-way clutch 77 and the pulley 72 using the housing 75, it is possible to reduce the load on the one-way clutch 77 in the radial direction.

Further, in this embodiment, when the one-way clutch 77 and the pulley 72 are connected using the housing 75, the position of the timing belt 74 in the axial direction AX of the shaft 71 can be regulated by the flange shape 72c and the flange shape 75b. There is. Thereby, there is no need to provide a flange shape at the end of the pulley 72 opposite to the flange shape 72c in the axial direction AX of the shaft 71. Therefore, the thickness in the axial direction AX can be reduced, and the space for arranging the one-way clutch 77 and pulley 72 inside the main body of the image forming apparatus 100 can be saved. Further, since the position of the timing belt 74 in the axial direction AX of the shaft 71 is restricted by the flange shape 72c and the flange shape 75b, it is possible to suppress the timing belt 74 from falling off from the pulley 72 in the axial direction AX.

Further, as described above, the tensioner 73 is arranged on the rotational orbit of the timing belt 74. In addition to applying tension to the timing belt 74, the tensioner 73 is provided with a flange shape that can regulate the position of the timing belt 74 in the axial direction AX of the shaft 71 (see FIG. 2). Thereby, the position of the timing belt 74 in the axial direction AX of the shaft 71 is regulated by the tensioner 73, and the effect of suppressing the timing belt 74 from falling off from the pulley 72 in the axial direction AX can be enhanced.

Note that the grooves 72d1 and 72d2 of the pulley 72 of this embodiment have a shape that allows a shaft 71' provided with pins 79, 79 to fit therein. As shown in FIG. 5, the shaft 71' is provided with holes (not shown) for mounting pins 79, 79 thereon. The pins 79, 79 may have other shapes, for example, such that the pins 79, 79 extend from the shaft 71' in a direction intersecting the axial direction AX and the side surface of the pulley 72. By fitting the grooves 72d1 and 72d2 with the pins 79 and 79, it is possible to transmit the rotation of the shaft 71' to the pulley 72 and rotate the pulley 72 regardless of the presence or absence of the one-way clutch 77. Become. In other words, the pulley 72 has a configuration in which the pulley 72 is rotated by the rotation of the shaft 71' with members such as pins 79, 79 that transmit the rotation of the shaft 71' to the pulley 72 fitted in the grooves 72d1 and 72d2. It can also be used for

Further, the outer diameter of the flange shape 75b of the housing 75 was set to be approximately the same outer diameter as the outer diameter of the flange shape 72c of the pulley 72. By doing this, even if the number of teeth on the circumferential surface 72b of the pulley 72 is reduced, the position of the timing belt 74 in the axial direction AX can be regulated by the flange shape 75b of the housing 75. Note that in FIGS. 2 to 5, the teeth on the surface of the circumferential surface 72b are omitted. Further, the outer diameter of the flange shape 75b of the housing 75 is made larger than the outer diameter of the flange shape 72c of the pulley 72, so that the circumferential surface 72b of the pulley 72 can regulate the position of the timing belt 74 using the housing 75. It is possible to increase the number of types of teeth. Note that, as the timing belt 74, a cogged belt corresponding to the number of teeth on the circumferential surface 72b of the pulley 72, a smooth belt that slides on the circumferential surface 72b without teeth, or the like can be used.

As described above, in this embodiment, the one-way clutch 77 can be connected to the pulleys 72 having different numbers of teeth using the housing 75, and there is no need to mold a special pulley having a shape to accommodate the one-way clutch. The pulley 72 may also be configured to rotate the pulley 72 by the rotation of the shaft 71' with members such as pins 79, 79 that transmit the rotation of the shaft 71' to the pulley 72 fitted in the grooves 72d1, 72d2. Since it can be repurposed, it is possible to realize cost reduction. Furthermore, in this embodiment, the position of the timing belt 74 in the axial direction AX of the shaft 71 can be regulated by the housing 75, and there is no need to provide a flange shape at the end of the pulley 72 opposite to the flange shape 72c. Therefore, the thickness in the axial direction AX can be reduced, and the space for arranging the one-way clutch 77 and pulley 72 inside the main body of the image forming apparatus 100 can be saved.

7 Registration roller pair (second sheet conveyance means) /41 Manual feed tray (sheet support section) /42a Feeding roller /42b Separation roller /46 Conveyance roller pair (sheet conveyance means, first sheet conveyance means) /46a Conveyance roller (Rotating body) / 46b Driven roller (opposed member) / 50, 54 Conveying section (second sheet conveying means) / 55 Skew correction section (second sheet conveying means) / 60, 61 Internal conveying roller pair (second sheet conveying means) / 60, 61 Transfer means)/71 Shaft/72 Pulley/72a Hole/72b Circumferential surface/72c Flange shape (first flange)/72d Engaged portion/72d1, 72d2 Cut groove/72d3, 72d4 Recess (engaged portion) )/73 Tensioner (tension applying mechanism)/74 Timing belt (belt)/75 Housing (connecting member)/75a Accommodating part/75b Flange shape (second flange part)/75c Engaging part/75c1, 75c2 Projection/77 One-way Clutch / 78 Drive motor (rotation drive means) / 79 Pin / 100 Image forming device (sheet conveying device) / PY, PM, PC, PK Image forming section (image forming means) / AX Axial direction / FD Conveying direction / N Nip Part/S Sheet

Claims (7)

a shaft, a rotating body rotatable about the shaft, and an opposing member that together with the rotating body forms a nip portion for conveying a sheet, and the rotating body is rotated in a first direction to transport the sheet to the nip portion. a sheet conveyance means for conveying the sheet sandwiched between the two;
a rotational drive means;
a belt that rotates due to the rotational drive of the rotational drive means;
a hole into which the shaft can be inserted, a circumferential surface over which the belt is stretched, and a position in the axial direction of the shaft of the belt stretched over the circumferential surface can be regulated, and one of the shafts in the axial direction; a pulley that rotates as the belt rotates;
The rotation of the pulley is transmitted to the shaft to rotate the rotary body in the first direction, and the rotational drive speed of the rotary body in the first direction is higher than the rotational drive speed of the rotary drive means in the first direction. a one-way clutch that allows the rotating body to rotate at a high rotational speed;
an accommodating part that accommodates the one-way clutch at a position different from the pulley in the axial direction; an engaging part that can engage the engaged part; and the engaging part and the engaged part are engaged. a second flange portion capable of regulating the position in the axial direction of the belt that is stretched over the circumferential surface in a state in which the belt is stretched around the circumferential surface, and a connecting member that connects the pulley and the one-way clutch;
A sheet conveying device characterized by: The engaged portion is a groove extending radially from the hole in the radial direction of the circumferential surface,
The engaging portion is a protrusion that can fit into the cut groove.
The sheet conveying device according to claim 1, characterized in that: The kerf has a shape in which a member attached to the shaft and capable of transmitting rotation of the shaft to the pulley can fit therein;
The one-way clutch transmits the rotation of the pulley to the shaft by fitting the cut groove and the protrusion to make the rotary body rotatable in the first direction, and the rotation drive means Allowing the rotation of the rotating body in a state where the rotational speed of the rotating body in the first direction is higher than the rotational driving speed of the rotating body in the first direction.
The sheet conveying device according to claim 2, characterized in that: a tension applying mechanism disposed between the driving means and the pulley in the rotation orbit of the belt and applying tension to the belt;
The sheet conveying device according to any one of claims 1 to 3. The sheet conveying means is a first sheet conveying means,
a second sheet conveying means disposed downstream of the first sheet conveying means in the sheet conveying direction;
The one-way clutch allows the rotating body to rotate in a state where the sheet conveying speed by the second sheet conveying means is higher than the sheet conveying speed by the first sheet conveying means.
The sheet conveying device according to any one of claims 1 to 4. a seat support portion on which the seat is supported;
a feeding roller disposed upstream of the first sheet conveying means in the sheet conveying direction and capable of feeding the sheet supported by the sheet supporting section;
a separation roller disposed so as to be in contact with the feeding roller and rotatable following rotation of the feeding roller;
The first sheet conveying means conveys the sheet fed by the feeding roller toward the second sheet conveying means.
The sheet conveying device according to claim 5, characterized in that: A sheet conveying device according to any one of claims 1 to 6,
an image forming unit that forms an image on a sheet conveyed by the sheet conveyance device;
An image forming apparatus characterized by:

Images