JP7056076B2 - Rotational transmission structure, transfer device, image forming device and transmission member - Google Patents

Description

The present invention relates to a rotation transmission structure, a transfer device, an image forming device, and a transmission member.

Patent Document 1 discloses a gear device in which a convex portion of a rotating shaft is hooked in a concave portion of a reinforcing member attached to a gear.

Japanese Unexamined Patent Publication No. 2016-53392

There is a rotation transmission structure in which the first axis is rotationally driven, power is supplied to the second axis, the rotation of the first axis is transmitted to the second axis, and insulation is performed between the first axis and the second axis. Here, when a resin transmission member is used as the transmission member for transmitting the rotation of the first axis to the second axis, insulation can be ensured, but the rotation direction of the transmission member is higher than that of the metal transmission member. Rigidity against force is reduced.

The present invention comprises a configuration in which the first axis is rotationally driven, power is supplied to the second axis, the rotation of the first axis is transmitted to the second axis, and insulation is performed between the first axis and the second axis. The purpose is to increase the rigidity of the transmission member with respect to the force in the rotational direction, as compared with the configuration in which the input portion and the output portion of the force in the rotational direction are arranged so as to be offset in the axial direction.

The rotation transmission structure according to the first aspect is located apart from the rotation-driven first axis, the second axis to be fed, and the axis of the first axis, and rotates integrally with the first axis. The first engaging portion, the second engaging portion that is located away from the axis of the second axis and rotates integrally with the second axis, and the first engaging portion and the second engaging portion that are made of resin and are made of resin. It has a transmission portion sandwiched between the engaging portion and the rotation direction, and has a transmission member that transmits the rotation of the first axis to the second axis.

The transmission portion of the rotation transmission structure according to the second aspect includes a portion of the transmission member arranged at least outside the center from the axial center to the outer peripheral surface of the transmission member in the radial direction.

In the rotation transmission structure according to the third aspect, when the transmission unit is viewed from the axial direction of rotation, the first width in the rotation direction in the radial outer portion of the transmission unit is the diameter of the transmission unit. It is wider than the second width in the rotation direction in the inner portion in the direction.

The transmission member of the rotation transmission structure according to the fourth aspect is arranged on one side in the rotation direction with respect to the transmission portion, is recessed from one side in the axial direction of rotation to the other side, and the first engagement portion. A first recess into which the second engaging portion is inserted, a second recess arranged on the other side in the rotational direction with respect to the transmission portion, a recess from the other side in the axial direction toward one side, and a shaft into which the second engaging portion is inserted. A recess in the direction, the first shaft or the second shaft is attached, the first concave portion or the attached portion connected to the second concave portion is formed, and the first engaging portion has a diameter from the first shaft. It extends outward in the direction or the second engaging portion extends radially outward from the second axis.

A recessed portion is formed inside the transmission portion of the rotation transmission structure according to the fifth aspect in the radial direction, which is recessed on the side away from the first engaging portion or the second engaging portion in the rotational direction. There is.

In the transmission member of the rotation transmission structure according to the sixth aspect, a blocking portion is formed which is arranged between the first axis and the second axis and cuts off the conduction from the second axis to the first axis. Has been done.

In the rotation transmission structure according to the seventh aspect, the second engaging portion extends radially outward from the second axis, and the radial second from the rotation center of the transmission member to the tip of the second engaging portion. One length is set to be equal to or greater than the second radial length from the center of rotation to the outer end of the first engaging portion.

The first engaging portion of the rotation transmission structure according to the eighth aspect is made of metal.

The transfer device according to the ninth aspect includes the rotation transmission structure according to any one of the first to eighth aspects, a drive source for rotating the first axis, a power supply for supplying power to the second axis, and the like. A holding member wound around the second shaft and holding the developer and a developing agent of the holding member provided on the side opposite to the second shaft side with respect to the holding member and having a potential difference with the second shaft. It has a transfer member to be transferred to a recording medium.

The image forming apparatus according to the tenth aspect includes the transfer apparatus according to the ninth aspect, a developing agent image forming portion for forming a developing agent image by using a developing agent on the holding member, and a developing agent transferred to a recording medium. It has a fixing portion for fixing to a recording medium.

The transmission member according to the eleventh aspect transmits a rotational force from a first engaging portion that rotates integrally with a rotation-driven first shaft to a second engaging portion that rotates integrally with a second shaft to be fed. It is a transmission member, is made of resin, and has a transmission portion that is sandwiched between the first engagement portion and the second engagement portion in the rotational direction.

According to the rotation transmission structure of the first aspect, the first axis is rotationally driven, power is supplied to the second axis, the rotation of the first axis is transmitted to the second axis, and insulation is performed between the first axis and the second axis. In this configuration, the rigidity of the transmission member with respect to the rotational force can be increased as compared with the configuration in which the input portion and the output portion of the force in the rotational direction of the transmission member are arranged so as to be displaced in the axial direction.

According to the rotation transmission structure of the second aspect, the transmission unit is arranged to transmit torque in order to transmit torque, as compared with the configuration in which the transmission unit is arranged only inside the center from the axial center to the outer peripheral surface of the transmission member in the radial direction. The acting force can be reduced.

According to the rotation transmission structure of the third aspect, the deformation of the radial outer portion of the transmission portion can be suppressed as compared with the configuration in which the first width is narrower than the second width.

According to the rotation transmission structure of the fourth aspect, the rigidity of the first engaging portion or the second engaging portion with respect to the force in the rotational direction is increased as compared with the configuration in which the attached portion is not connected to the first concave portion or the second concave portion. Can be enhanced.

According to the rotational transmission structure of the fifth aspect, it is possible to eliminate the transmission of the rotational force at a portion where the transmission of the rotational force is unnecessary.

According to the rotation transmission structure of the sixth aspect, the conduction from the second axis to the first axis is suppressed as compared with the configuration in which the first axis or the second axis in the attached portion is exposed toward the other side. Can be done.

According to the rotation transmission structure of the seventh aspect, it is possible to prevent the range in which the rotational force is transmitted from being narrowed in the radial direction as compared with the configuration in which the first length is shorter than the second length.

According to the rotation transmission structure of the eighth aspect, the rigidity of the transmission member with respect to the force in the rotation direction can be increased as compared with the structure in which the first engaging portion is made of resin.

According to the transfer device of the ninth aspect, the transfer position shift of the developer to the recording medium is suppressed as compared with the configuration which does not have the rotation transmission structure according to any one of the first to the eighth aspects. can do.

According to the image forming apparatus of the tenth aspect, image defects can be suppressed as compared with the configuration which does not have the transfer apparatus according to the ninth aspect.

According to the transmission member of the eleventh aspect, the first axis is rotationally driven, power is supplied to the second axis, the rotation of the first axis is transmitted to the second axis, and insulation is performed between the first axis and the second axis. In the configuration, the rigidity of the transmission member with respect to the rotational force can be increased as compared with the configuration in which the input portion and the output portion of the rotational force of the transmission member are arranged so as to be displaced in the axial direction.

It is explanatory drawing which shows the image forming apparatus which concerns on this embodiment. It is a partially enlarged perspective view of the transfer apparatus which concerns on this embodiment. It is sectional drawing of the rotation transmission structure which concerns on this embodiment. It is a side view of the rotation transmission structure which concerns on this embodiment. (A) is a perspective view of the coupling member according to the present embodiment as viewed from the mounting side, and (B) is a perspective view of the coupling member according to the present embodiment as viewed from the non-mounting side. It is explanatory drawing which saw the coupling member which concerns on this embodiment from the axial direction. (A) It is a perspective view which shows the shaft part and the engagement pin of the drive roll which concerns on this embodiment, and (B) is the cross-sectional view which shows the shaft part and the engagement pin of the drive roll which concerns on this embodiment. It is explanatory drawing which looked at the transmission member which concerns on this embodiment from the axial direction. (A) is a perspective view of the transmission member according to the present embodiment as viewed from the mounting side, and (B) is a perspective view of the transmission member according to the present embodiment as viewed from the non-mounting side. It is sectional drawing in the direction orthogonal to the axial direction of the transmission member which concerns on this embodiment. It is explanatory drawing which enlarged a part of the transmission member which concerns on this embodiment. It is sectional drawing which shows the connection state of the coupling member and the transmission member which concerns on this embodiment.

An example of the rotation transmission structure, the transfer device, the image forming device, and the transmission member according to the present embodiment will be described.

〔overall structure〕
FIG. 1 shows the image forming apparatus 10 of the present embodiment. In the following description, the direction indicated by the arrow Y is the device height direction, and the direction indicated by the arrow X is the device width direction. Further, the direction (indicated by Z) orthogonal to each of the device height direction and the device width direction is defined as the device depth direction. Then, the image forming apparatus 10 is viewed from the front, and the apparatus height direction, the apparatus width direction, and the apparatus depth direction are described as Y direction, X direction, and Z direction. When it is necessary to distinguish between one side and the other side in the X direction, the Y direction, and the Z direction, the upper side is the Y side, the lower side is the −Y side, and the right side is the X side when the image forming apparatus 10 is viewed from the front. , The left side is described as -X side, the back side is described as Z side, and the front side is described as -Z side.

The image forming apparatus 10 has an apparatus main body 12 formed in a box shape. A mounted portion 14 to which the transfer device 30 described later is mounted in the Z direction is provided in the device main body 12. The mounted portion 14 has a plate portion 14A and a plate portion 14B extending in the Z direction with the Y direction as the thickness direction. By mounting the support member 32 described later of the transfer device 30 on the plate portion 14A and the plate portion 14B, the transfer device 30 is mounted on the mounted portion 14.

Further, an opening 16 opened in the Z direction is formed on the side wall on the −Z side of the apparatus main body 12. A hinge portion (not shown) that is rotatable about the X direction is provided at the −Y side end portion of the opening portion 16. The −Y side end of the cover member 18 is attached to the movable portion of the hinge portion. The cover member 18 is movable around the hinge portion in an arc shape between a closing position for closing the opening 16 and an opening position for opening the opening 16. The cover member 18 is arranged so as to cover the −Z side of the transfer device 30 in a state where the transfer device 30 described later is mounted on the mounted portion 14.

The image forming apparatus 10 includes a conveying unit 22, an image forming unit 24, a transfer device 30, a fixing unit 26, and a control unit 28. Further, in the image forming apparatus 10, the toner image G is formed on the paper P as an example of the recording medium. The details of the transfer device 30 will be described later.

<Transport section>
The transport unit 22 is composed of a plurality of rolls including the alignment roll pair 23, and transports the sheet P of the sheet along the transport path A. As an example, the transport path A extends from the lower portion of the apparatus main body 12 on the −Y side to the upper portion on the Y side along the Y direction.

<Image forming part>
The image forming unit 24 is an example of a developer image forming unit, and has a plurality of image forming units 25. The plurality of image forming units 25 form a toner image G by using the toner T on the intermediate transfer belt 48 described later. Toner T is an example of a developer. The toner image G is an example of an image and a developer image. As an example, the plurality of image forming units 25 are configured to perform each step of charging, exposure, and development, which are known electrophotographic methods.

<Fixing part>
As an example, the fixing portion 26 has a fixing roll 26A heated by the halogen heater 26B and a pressure roll 26C that presses the paper P together with the fixing roll 26A. Then, the fixing unit 26 fixes the toner T (toner image G) transferred to the paper P by the transfer device 30 to the paper P by heating and pressurizing the toner T (toner image G).

<Control unit>
The control unit 28 is configured as a computer, and includes a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), and the like (not shown). The control unit 28 performs power supply from the power supply unit 56, which will be described later, to each part of the image forming apparatus 10, a paper P conveying operation by the conveying unit 22, an image forming operation by the image forming unit 24, an operation of the driving unit 54, which will be described later, and the like. Control.

[Main part composition]
Next, the transfer device 30 will be described.

As an example, the transfer device 30 includes a support member 32, a drive roll 74, a support roll 42, a tension roll 44, a plurality of primary transfer rolls 46, an intermediate transfer belt 48, a secondary transfer roll 52, and the like. It has a drive unit 54, a power supply unit 56, and a rotation transmission structure 70. The secondary transfer roll 52, the drive unit 54, and the power supply unit 56 are provided on the device main body 12 (see FIG. 1) side. Members other than the secondary transfer roll 52, the drive unit 54, and the power supply unit 56 can be integrally detached and attached to the apparatus main body 12.

As shown in FIG. 2, the support member 32 has, as an example, a first support member 33 and a second support member 34. The first support member 33 is configured to include a side plate along the XY plane and is arranged on the Z side. The second support member 34 is configured to include a side plate along the XY plane and is arranged on the −Z side. The first support member 33 and the second support member 34 are connected in the Z direction using a connecting member (not shown). Further, the first support member 33 and the second support member 34 rotatably support the drive roll 74, the support roll 42, the tension roll 44, and the plurality of primary transfer rolls 46 (all of which are seen in FIG. 1). The details of the drive roll 74 will be described later.

The support roll 42 shown in FIG. 1 is rotatable with the Z direction as the axial direction. The tension roll 44 is rotatable about the Z direction as an axial direction. Further, the tension roll 44 is adapted to apply tension to the intermediate transfer belt 48, which will be described later. The plurality of primary transfer rolls 46 are fed from the power supply unit 56 to primary transfer the toner image G to the intermediate transfer belt 48.

The intermediate transfer belt 48 is an example of a holding member, and is composed of an endless rubber belt. Further, the intermediate transfer belt 48 is wound around the drive roll 74, the support roll 42, and the tension roll 44, and can be rotated around by the rotation of the drive roll 74. Further, the toner image G is primarily transferred from the image forming unit 24 described above to the intermediate transfer belt 48. Then, the intermediate transfer belt 48 holds the primary transferred toner image G on the outer peripheral surface.

The secondary transfer roll 52 is an example of a transfer member, and is provided so as to be rotatable on the −X side with respect to the transport path A with the Z direction as the axial direction. Specifically, the secondary transfer roll 52 is provided on the side opposite to the drive roll 74 side with respect to the intermediate transfer belt 48. Further, the secondary transfer roll 52 transfers the toner image G (toner T) of the intermediate transfer belt 48 to the paper P (secondary transfer) by the potential difference from the fed drive roll 74.

(Drive part)
The drive unit 54 shown in FIG. 2 is an example of a drive source, and the presence / absence of drive is controlled by the control unit 28 (see FIG. 1). Further, the drive unit 54 has, for example, a motor 62 having a pinion 63, a transmission gear 64, and a drive gear 65. When the motor 62 is driven, the rotation of the pinion 63 is transmitted to the drive gear 65 via the transmission gear 64. The drive gear 65 is attached to a shaft member 72, which will be described later. That is, the drive unit 54 rotates the shaft member 72.

(Power supply unit)
The power supply unit 56 shown in FIG. 1 is an example of a power supply, and the presence / absence of power supply is controlled by the control unit 28. Further, the power supply unit 56 is electrically connected to a terminal member 66 (see FIG. 4) composed of a leaf spring. As shown in FIG. 4, the terminal member 66 is in contact with the outer peripheral surface of the shaft portion 77 of the drive roll 74. The power supply unit 56 (see FIG. 1) supplies power to the shaft portion 77 (drive roll 74) via the terminal member 66.

<Rotation transmission structure>
Next, the rotation transmission structure 70 will be described.

The rotation transmission structure 70 shown in FIG. 3 includes, as an example, a shaft member 72 as an example of the first shaft, a drive roll 74 as an example of the second shaft, and a coupling member 78 having a first engaging portion 76. , A engaging pin 82 having a second engaging portion 81 (see FIG. 7B), and a transmission member 84.

<Shaft member>
The shaft member 72 shown in FIG. 3 is made of stainless steel (metal) as an example, and is formed in a columnar shape with the Z direction as the axial direction. Further, the shaft member 72 is rotatably supported by brackets and bearings (not shown) provided on the main body 12 of the apparatus (see FIG. 1). The drive gear 65 described above is attached to the central portion of the shaft member 72 in the Z direction. On the −Z side of the shaft member 72 with respect to the drive gear 65, a groove portion 72A that is recessed in the radial direction along the circumferential direction is formed. A C ring 86 is fitted in the groove portion 72A.

A receiving member 88 is provided on the −Z side of the shaft member 72 with respect to the C ring 86. The receiving member 88 is a member formed in a U shape having a cross section along the Z direction opening toward the −Z side. The receiving member 88 is formed with a through hole 88A penetrating in the Z direction. A shaft member 72 is inserted into the through hole 88A. Further, a guide portion 72C formed of a long hole long in the Z direction is formed at the tip portion 72B of the shaft member 72 on the X side of the receiving member 88. The guide portion 72C guides the coupling member 78 in the Z direction by coming into contact with the pin member 93 described later. The shaft member 72 is grounded via a terminal member (not shown).

Here, a coil spring 89 is provided between the receiving member 88 and the coupling member 78 in a compressed state. Specifically, the receiving member 88 is restricted from moving on the Z side by coming into contact with the C ring 86. The coil spring 89 is sandwiched between the receiving member 88 and the coupling member 78 so as to be compressed in the Z direction. That is, the coupling member 78 is pressed toward the −Z side (transmission member 84 side) by the pressing force from the coil spring 89.

<Drive roll>
As an example, the drive roll 74 shown in FIG. 3 has a columnar main body portion 75 extending in the Z direction as an axial direction, and a shaft portion 77 extending outward from both ends of the main body portion 75 (only one end in the drawing). Have. The shaft portion 77 is rotatably supported by a bearing 39 provided on the support member 32 with the Z direction as the rotation axis direction. A through hole 77A penetrating in a direction (diameter direction) orthogonal to the axial direction is formed at the tip of the shaft portion 77. An engagement pin 82, which will be described later, is fixed to the through hole 77A by press fitting.

As shown in FIG. 1, the drive roll 74 is mounted on the apparatus main body 12 of the transfer device 30, at a location adjacent to the transport path A and on the X side with respect to the transport path, with the Z direction as the axial direction. It is said to be rotatable. The drive roll 74 is rotationally driven by transmitting a rotational force from the drive unit 54. Further, as shown in FIG. 4, power is supplied to the shaft portion 77 of the drive roll 74 from the power supply unit 56 (see FIG. 1) via the terminal member 66.

<Coupling member>
As shown in FIG. 5B, the coupling member 78 is, for example, a metal member formed by sintering iron powder, and has a mounting portion 92, a flange portion 94, and a first. It has an engaging portion 76.

(Mounting part)
The mounting portion 92 is formed in a cylindrical shape with the Z direction as the axial direction. The size of the inner diameter of the mounting portion 92 is such that the shaft member 72 (see FIG. 3) can be inserted. Further, two through holes 92A penetrating in a direction intersecting the Z direction (diametrical direction of the mounting portion 92) are formed in a part of the circumferential direction of the mounting portion 92. A columnar pin member 93 (see FIG. 3) is inserted into the through hole 92A with the shaft member 72 inserted into the mounting portion 92. Both ends of the pin member 93 are fixed to the mounting portion 92 using screws (not shown). As shown in FIG. 3, the pin member 93 is inserted into the guide portion 72C described above, and is guided in the Z direction by the guide portion 72C. As a result, the coupling member 78 can move relative to the shaft member 72 in the Z direction.

(Flange part)
The flange portion 94 shown in FIG. 5B is a plate-shaped portion protruding outward in the radial direction from the outer peripheral surface of the Z-side end portion of the mounting portion 92. Further, the flange portion 94 is formed in an annular shape when viewed from the Z direction.

(1st engaging part)
As an example, the first engaging portion 76 shown in FIG. 5A includes a first protrusion 102 and a second protrusion 104 extending from the Z-side end faces of the mounting portion 92 and the flange portion 94 toward the Z side along the Z direction. Have. Both the first protrusion 102 and the second protrusion 104 have a length of L3 in the Z direction.

As shown in FIG. 6, the first protrusion 102 and the second protrusion 104 are located apart from the axial center of the shaft member 72 (indicated by the point C1) to the outside of the mounting portion 92 in the radial direction. Further, the first protrusion 102 and the second protrusion 104 are rotated integrally with the shaft member 72 in a state where the mounting portion 92 (see FIG. 5A) is mounted on the shaft member 72. The first protrusion 102 and the second protrusion 104 are arranged so as to be point-symmetrical with respect to the point C1 when viewed from the Z direction. Let L2 be the second length in the radial direction from the point C1 to the outer end of the first engaging portion 76.

The first protrusion 102 has a side surface 102A, a side surface 102B, an inner peripheral surface 102C, an outer peripheral surface 102D, and an end surface 102E. When the first protrusion 102 is viewed from the Z direction, the side surface 102A and the side surface 102B are each indicated by a line segment along the radial direction. The side surface 102A is a surface arranged on the upstream side of the first engaging portion 76 in the rotation direction (indicated by an arrow R) and orthogonal to the rotation direction. The side surface 102B is a surface arranged on the downstream side in the rotation direction of the first engaging portion 76 and orthogonal to the rotation direction. The inner peripheral surface 102C connects the inner end of the side surface 102A and the inner end of the side surface 102B when viewed from the Z direction, and has an arc shape (arc shape centered on the point C1) that is convex outward in the radial direction. It is formed.

The outer peripheral surface 102D is formed in an arc shape that connects the outer end of the side surface 102A and the outer end of the side surface 102B when viewed from the Z direction and is convex outward in the radial direction. The end surface 102E is a surface of the first protrusion 102 on the side opposite to the flange portion 94 side in the Z direction. As an example, the first protrusion 102 has a size corresponding to approximately 1/6 (central angle of arc 60 °) in the circumferential direction of the flange portion 94 when viewed from the Z direction.

The second protrusion 104 has a side surface 104A, a side surface 104B, an inner peripheral surface 104C, an outer peripheral surface 104D, and an end surface 104E. The side surface 104A, the side surface 104B, the inner peripheral surface 104C, the outer peripheral surface 104D, and the end surface 104E are arranged so as to be point-symmetrical with the side surface 102A, the side surface 102B, the inner peripheral surface 102C, the outer peripheral surface 102D, and the end surface 102E with respect to the point C1. Has been done. R-shaped chamfered portions (hereinafter referred to as R portions) are formed at both ends in the radial direction on the side surface 102A, the side surface 102B, the side surface 104A, and the side surface 104B, respectively. The radial lengths of the side surface 102A, the side surface 102B, the side surface 104A, and the side surface 104B excluding the R portion are aligned to L4 (<L2), respectively.

<engagement pin>
The engagement pin 82 shown in FIG. 7A is formed in a columnar shape as an example. Further, the engaging pin 82 is press-fitted into the through hole 77A of the shaft portion 77 so that both ends in the axial direction are exposed to the outside with respect to the shaft portion 77.

As shown in FIG. 7B, the engaging pin 82 has a central portion 82A in the axial direction press-fitted into the through hole 77A. As an example, the axial length of the central portion 82A is set to be about 1/3 of the total length of the engaging pin 82 in the axial direction. Further, the diameter of the engaging pin 82 is d1. As an example, the length of the diameter d1 is shorter than the above-mentioned length L3 (see FIG. 5A). The portion of the engaging pin 82 excluding the central portion 82A and exposed to the outside from the outer peripheral surface of the shaft portion 77 is referred to as a second engaging portion 85.

The second engaging portion 85 extends radially outward from the shaft portion 77. In other words, the second engaging portion 85 is exposed to the shaft portion 77 with substantially the same length on one side and the other side in the axial direction of the engaging pin 82. Further, the second engaging portion 85 is located apart from the axial center of the shaft portion 77 (indicated by the point C2) on the outer side in the radial direction. Further, the second engaging portion 85 is rotated integrally with the shaft portion 77 (drive roll 74). The radial length from the point C2 to the tip of the second engaging portion 85 is defined as the first length L1. The first length L1 is set to be equal to or larger than the above-mentioned second length L2 (see FIG. 6). In the present embodiment, as an example, the first length L1 is longer than the second length L2. Further, the first length L1 is shorter than the radial length L5 from the point C2 to the inner peripheral surface 124B (see FIG. 10) described later.

<Transmission member>
The transmission member 84 shown in FIG. 8 is, for example, a resin member made of polyphenylene sulfide (PPS) resin. Further, the transmission member 84 is formed in a columnar shape with the Z direction as the axial direction, and is arranged on the front side 84A (see FIG. 9B) having a circular outer shape arranged on the −Z side and on the Z side. It has a rear surface 84B having a circular outer shape and an outer peripheral surface 84C. The length of the transmission member 84 in the Z direction is shorter than the length corresponding to the diameters of the front surface 84A and the rear surface 84B. Further, the transmission member 84 has an insulating property. In the present embodiment, having an insulating property means that the volume resistivity at 20 ° C. is 1 × 10 ¹⁴ Ω · cm or more. The center of rotation of the transmission member 84 overlaps with the point C2.

As an example, the transmission member 84 includes a mounted portion 112, a transmission portion 114, 116, a first recess 118, 122, a second recess 124, 126, a partition wall portion 128, 132, and a blocking portion 134. It is formed. It should be noted that each part of the transmission member 84 will be described as being in an arrangement state in which the transmission member 84 is assembled to the transfer device 30 (see FIG. 1) with the Z direction as the axial direction. Further, the rotation direction of the transmission member 84 is the same as the rotation direction of the drive roll 74 (see FIG. 1), and when the −Z side is viewed from the Z side in the Z direction, as an example, in the counterclockwise direction. It is supposed to rotate. Hereinafter, this rotation direction is referred to as an R direction.

(Attached part)
As shown in FIG. 9B, the attached portion 112 is a portion (hole wall) recessed from the central portion including the center of the front surface 84A toward the Z side in the Z direction. A tapered surface is formed on the opening edge on the −Z side of the mounted portion 112. Further, the attached portion 112 has a circular shape when viewed from the Z direction. The radius of the attached portion 112 is set to be smaller than 1/2 of the radius of the transmission member 84. The Z-side end of the shaft portion 77 (see FIG. 3) is fitted into the mounted portion 112. That is, the drive roll 74 (see FIG. 3) is attached to the attached portion 112.

(Transmission part)
The transmission unit 114 and the transmission unit 116 shown in FIG. 10 extend radially outward from the outer peripheral portion of the attached portion 112 when viewed from the Z direction. The transmission portion 114 is a portion that comes into contact with the side surface 102B (see FIG. 5A) of the first protrusion 102 in the R direction. The transmission portion 116 is a portion that comes into contact with the side surface 104B (see FIG. 5A) of the second projection 104 in the R direction. The transmission unit 114 and the transmission unit 116 are formed so as to be point-symmetrical with respect to the point C2 as an example. Therefore, the transmission unit 114 will be described, and the description of the transmission unit 116 will be omitted.

The transmission unit 114 is a portion of the transmission member 84 that is arranged at least outside the center (the position is indicated by the point D) from the point C2 (axis center) in the radial direction to the outer peripheral surface 84C of the transmission member 84. Includes. As an example, the transmission unit 114 extends not only to the outside of the point D but also to the inside of the point D. Further, when the transmission unit 114 is viewed from the Z direction (axial direction of rotation), the first width W1 in the R direction in the radial outer portion of the transmission unit 114 is R in the radial inner portion of the transmission unit 114. Wider than the second width W2 in the direction. In other words, the transmission portion 114 is formed in a fan shape in which the outer side in the radial direction is wider than the inner side in the cross-sectional shape when viewed from the Z direction. Further, the transmission portion 114 has a similar cross-sectional shape and extends in the Z direction.

In the transmission unit 114, the surface located on the upstream side in the R direction is referred to as the upstream surface 114A, and the surface located on the downstream side is referred to as the downstream surface 114B. As an example, the upstream surface 114A is a plane orthogonal to the R direction. Further, the upstream surface 114A constitutes a part of the wall surface of the first recess 118. As described above, the side surface 102B of the first protrusion 102 (see FIG. 5A) comes into contact with the upstream surface 114A. The downstream surface 114B is a surface with a step in which a recessed portion 136, which will be described later, is formed.

(1st recess)
The first recesses 118 and 122 shown in FIG. 9A are arranged on one side (upstream side) in the R direction with respect to the transmission portions 114 and 116, and are arranged from one side (Z side) in the Z direction to the other side (−Z side). ), Which is the part where the first engaging portion 76 (see FIG. 6) enters.

Specifically, the first recess 118 is a portion recessed from the outer side in the radial direction toward the −Z side in the Z direction from the central portion of the rear surface 84B. A tapered surface is formed on the Z-side opening edge of the first recess 118. Further, the first recess 118 has an arc shape centered on the point C2 (see FIG. 10) when viewed from the Z direction. In other words, the first recess 118 is a recess extending along the R direction. The first protrusion 102 (see FIG. 6) is inserted into the first recess 118 so as to be relatively movable in the R direction with respect to the first recess 118. The spread angle (central angle) of the first recess 118 when viewed from the Z direction is, as an example, about 120 °.

The first recess 122 is a portion recessed from the outer side in the radial direction toward the −Z side in the Z direction from the central portion of the rear surface 84B. A tapered surface is formed on the Z-side opening edge of the first recess 122. A second protrusion 104 (see FIG. 6) is inserted into the first recess 122 so as to be relatively movable in the R direction with respect to the first recess 122. As an example, the first recess 122 is formed so as to be point-symmetrical with the first recess 118 with the point C2 as the center when viewed from the Z direction. Therefore, a detailed description of the first recess 122 will be omitted.

(Second recess)
The second recesses 124 and 126 shown in FIG. 10 are arranged on the other side (downstream side) in the R direction with respect to the transmission portions 114 and 116. Further, as shown in FIG. 9B, the second recesses 124 and 126 are recessed from the other side (−Z side) in the Z direction toward one side (Z side), and the second engaging portion 85 (FIG. 9). 7 (B)) is the part to enter.

Specifically, the second recess 124 and the second recess 126 are portions recessed from the outer side in the radial direction toward the Z side in the Z direction with respect to the central portion of the front surface 84A. A tapered surface is formed on the opening edge of the second recess 124 and the second recess 126 on the −Z side. Further, the second recess 124 and the second recess 126 have a linear shape extending from the central portion of the front surface 84A to one side and the other side in the radial direction when viewed from the Z direction.

In other words, the second recess 124 and the second recess 126 and the attached portion 112 are linearly connected in the radial direction of the transmission member 84. A second engaging portion 85 (see FIG. 7B) is fitted into the second recess 124 and the second recess 126. Here, as shown in FIG. 10, as an example, the second recess 124 is formed so as to be point-symmetrical with the second recess 126 about the point C2 when viewed from the Z direction. Therefore, the second recess 124 will be described below, and the detailed description of the second recess 126 will be omitted.

The second recess 124 has the above-mentioned downstream surface 114B, the facing surface 124A, and the inner peripheral surface 124B when viewed from the Z direction. The facing surface 124A is arranged on the downstream side in the R direction with respect to the downstream surface 114B, extends outward in the radial direction from the attached portion 112, and faces the downstream surface 114B in the R direction. The inner peripheral surface 124B is a surface that connects the radial outer end of the downstream surface 114B and the radial outer end of the facing surface 124A in the R direction.

A recess 136 is formed inside the downstream surface 114B (transmission portion 114) in the radial direction. The recessed portion 136 is recessed on the side that widens the second recessed 124 in the R direction. In other words, the recessed portion 136 is recessed on the side away from the second engaging portion 85 (see FIG. 7B) in the R direction.

Further, a recessed portion 138 is formed in a portion of the facing surface 124A that is inside in the radial direction and that faces the recessed portion 136 in the R direction. The recessed portion 138 is recessed on the side where the second recessed 124 is widened in the R direction. Here, when the second engaging portion 85 (see FIG. 7B) is fitted into the second recess 124, the second engaging portion 85 comes into contact with the downstream surface 114B and the facing surface 124A, but the second engaging portion 85 2 The engaging portion 85 and the recessed portion 136 and the recessed portion 138 are prevented from coming into contact with each other.

(Partition wall)
The partition wall portion 128 shown in FIG. 10 is a wall portion extending linearly along the radial direction from the mounted portion 112 when viewed from the Z direction. Further, the partition wall portion 128 partitions the second recess 124 and the first recess 122 in the R direction. The partition wall portion 132 is a wall portion extending linearly in the radial direction from the mounted portion 112 when viewed from the Z direction. Further, the partition wall portion 132 partitions the second recess 126 and the first recess 118 in the R direction.

(Blocking part)
As shown in FIG. 9A, the blocking portion 134 is formed in a disk shape integrally with the transmission member 84 at the central portion of the rear surface 84B, and is formed in the mounted portion 112 (see FIG. 9B). The shaft portion 77 (see FIG. 3) of the positioned drive roll 74 is covered from the Z side. That is, as an example, the blocking portion 134 is made of a resin member having the same insulating properties as the transmitting member 84. Further, as shown in FIG. 3, the cutoff portion 134 is arranged between the shaft member 72 and the drive roll 74 in the Z direction. As a result, the cutoff unit 134 cuts off the conduction from the power-fed drive roll 74 to the grounded shaft member 72 together with the transmission member 84.

Here, as shown in FIG. 12, in the transmission member 84, in the state where the second engagement portion 85 is attached, the first engagement portion 76 comes into contact with the transmission unit 114 and the transmission unit 116, whereby the transmission unit The 114 and the transmission portion 116 are sandwiched between the first engaging portion 76 and the second engaging portion 85 in the R direction. As a result, the rotation of the shaft member 72 (see FIG. 3) is transmitted to the shaft portion 77 of the drive roll 74 (see FIG. 3) via the transmission member 84.

<Arrangement of each part>
The arrangement relationship of each part in the transmission part 114 and the peripheral part of the transmission part 114 will be specifically described with reference to FIG. FIG. 11 schematically shows a state in which the transmission portion 114 of the transmission member 84 and the peripheral portions of the transmission portion 114 are viewed from the Z direction. The first projection 102 and the engaging pin 82 are in contact with the transmission portion 114.

In FIG. 11, the end point located on the innermost side in the radial direction on the upstream surface 114A is referred to as a point a, and the end point located on the outermost side is referred to as a point d. Further, the innermost end point in the radial direction on the side surface 102B in contact with the upstream surface 114A is referred to as a point b, and the outermost end point is referred to as a point c. The points a, b, c, and d are arranged in this order on a straight line (not shown) from the inside to the outside in the radial direction.

On the other hand, on the downstream surface 114B, the end point located on the outermost side in the radial direction is referred to as a point e, and the end point located on the innermost side is referred to as a point k. Further, on the downstream surface 114B, the outermost end point along the radial direction of the portion where the downstream surface 114B and the engaging pin 82 come into contact is defined as a point f, and the innermost end point is defined as a point g. Further, the end point located on the outermost side in the radial direction of the bottom surface of the recessed portion 136 along the radial direction is defined as the point h. The points e, f, g, h, and k are arranged in this order from the outside to the inside along the radial direction when viewed from the R direction. In the present embodiment, an outline connecting points a, b, c, d, e, f, g, h, and k is included, and a region inside the outline (indicated by diagonal lines). ) Corresponds to the transmission unit 114.

The arc ak connecting the points a and k along the R direction is represented by the virtual line K1. Further, the arc de connecting the point d and the point e along the R direction is represented by the virtual line K6. The line segment gh represents a step (as an example, an inclined surface) between the downstream surface 114B and the bottom surface of the recessed portion 136. This inclined surface is inclined so that the upstream side in the R direction is closer to the point C2 than the downstream side.

Further, the line passing through the point b and along the R direction is the virtual line K2, the line passing through the point g and along the R direction is the virtual line K3, the line passing through the point c and along the R direction is the virtual line K4, and the point f. The line along the street R direction is referred to as a virtual line K5. The virtual lines K1, K2, K3, K4, K5, and K6 are arranged in this order from the inside to the outside in the radial direction of the transmission member 84.

Here, the length of the line segment CD corresponds to the above-mentioned length L4 (see FIG. 6). The radial length L6 from the point C2 to the virtual line K4 is shorter than the above-mentioned length L2. The radial length L7 from the point C2 to the virtual line K5 is shorter than the above-mentioned length L1 and longer than the length L2.

[Action]
Next, the operation of this embodiment will be described.

In the rotation transmission structure 70 shown in FIG. 3, since the transmission member 84 is made of an insulating resin, it is insulated between the shaft member 72 and the drive roll 74. As shown in FIG. 12, the first engaging portion 76, the transmitting portion 114, and the second engaging portion 85 are arranged in the R direction (at substantially the same position in the Z direction). Therefore, the transmission unit 114 is in a compressed state, and it becomes difficult for a twisting force due to torque transmission to act on the transmission unit 114. As a result, in the rotation transmission structure 70, the rigidity of the transmission member 84 with respect to the force in the R direction is higher than that in the configuration in which the input portion and the output portion of the force in the R direction of the transmission member 84 are arranged so as to be offset in the Z direction. Become.

Further, in the rotation transmission structure 70, the transmission portion 114 includes a portion at least outside the center from the axial center (point C2) in the radial direction to the outer peripheral surface 84C. Therefore, as compared with the configuration in which the transmission portion 114 is arranged only inside the center from the axial center to the outer peripheral surface 84C in the radial direction, the distance from the axial center to the point of action of the force is longer, so that the torque is increased. The force acting on the transmission unit 114 for transmission becomes smaller.

Further, in the rotation transmission structure 70, the first width W1 (see FIG. 10) of the radial outer portion of the transmission portion 114 is wider than the second width W2 (see FIG. 10) of the radial inner portion. That is, since the outer portion in the radial direction is thicker than the inner portion, the deformation of the outer portion in the radial direction of the transmission portion 114 is suppressed as compared with the configuration in which the first width W1 is the same as the second width W2.

In addition, in the rotation transmission structure 70, since the attached portion 112 is connected to the second recess 124 and the second recess 126, the second engaging portion 85 is integrated with the shaft portion 77. As a result, the rigidity of the second engaging portion 85 with respect to the force in the R direction is increased as compared with the configuration in which the attached portion 112 is not connected to the second recess 124 and the second recess 126.

Further, in the rotation transmission structure 70, a recessed portion 136 is formed inside the transmission portion 114 in the radial direction. In the recessed portion 136, since a gap is formed between the transmission member 84 and the second engaging portion 85, the rotational force is not transmitted from the first engaging portion 76 to the second engaging portion 85. Further, the recessed portion 136 is not a portion on which a rotational force acts in the R direction from the first engaging portion 76. That is, in the rotation transmission structure 70, the transmission of the rotational force is eliminated at the portion where the transmission of the rotational force is unnecessary.

Further, in the rotation transmission structure 70, a blocking portion 134 (see FIG. 3) having an insulating property is formed between the shaft member 72 and the shaft portion 77. Therefore, the conduction from the drive roll 74 (shaft portion 77) to the shaft member 72 is suppressed as compared with the configuration in which the shaft portion 77 in the mounted portion 112 is exposed toward the other side (shaft member 72). ..

In addition, in the rotation transmission structure 70, the first length L1 in the radial direction from the center of rotation (point C2) to the tip of the second engaging portion 85 (see FIG. 7B) is the first engagement from the point C2. It is longer than the second radial length L2 (see FIG. 6) to the outer end of the joint portion 76. Therefore, as compared with the configuration in which the first length L1 is shorter than the second length L2, it is suppressed that the range in which the rotational force is transmitted to the second engaging portion 85 is narrowed in the radial direction.

Further, in the rotation transmission structure 70, since the first engaging portion 76 is made of metal, the rigidity of the transmission member 84 with respect to the force in the R direction is higher than that of the configuration in which the first engaging portion 76 is made of resin.

In the transfer device 30 shown in FIG. 2, since the rotation transmission structure 70 suppresses the decrease in rigidity of the transmission member 84 with respect to the force in the rotation direction, the drive roll 74 (see FIG. 1) is rotated in accordance with the rotation of the shaft member 72. It is rotated. As a result, the transfer position shift of the toner T to the paper P is suppressed as compared with the configuration without the rotation transmission structure 70.

In the image forming apparatus 10 shown in FIG. 1, since the transfer position shift of the toner T to the paper P by the transfer apparatus 30 is suppressed, an image defect (for example, a toner image) is suppressed as compared with a configuration without the transfer apparatus 30. G deviation) is suppressed.

The present invention is not limited to the above embodiment.

The number of the transmission units 114 and 116 is not limited to two, and may be one or three or more. Further, the transmission units 114 and 116 may be arranged only inside the center of the transmission member 84 from the axial center to the outer peripheral surface 84C in the radial direction. Further, the first width W1 of the transmission portions 114 and 116 may be the same as or narrower than the second width W2.

The shaft member 72 may be attached to the attached portion 112 and may be connected to the first recesses 118 and 122. In this configuration, the first engaging portion 76 may extend radially outward from the shaft member 72.

The transmission member 84 may not have a recessed portion 136 formed therein. Further, the transmission member 84 may not have the blocking portion 134 formed. Further, in the transmission member 84, the first length L1 from the center of rotation to the tip of the second engaging portion 85 is the same as or the second length L2 from the center of rotation to the outer end of the first engaging portion 76. It may be shorter than the second length L2. Further, the transmission member 84 is not limited to the PPS resin, and may be another resin, for example, may be composed of an acrylonitrile-butadiene-styrene copolymer (ABS) resin.

The first engaging portion 76 is not limited to the sintered body, and may be formed by cutting or the like. Further, the first engaging portion 76 may be a sulfur composite free-cutting steel (SUM) surface-treated. Further, the first engaging portion 76 may be made of resin. The number of the first recesses 118, 122 and the second recesses 124, 126 is not limited to two, and may be one or three or more.

The second engaging portion 85 is not limited to the one in which one engaging pin 82 is press-fitted into the through hole 77A of the shaft portion 77, and the second engaging portion 85 is formed with recesses on one side and the other side in the radial direction of the shaft portion 77. One pin may be fixed to each of the two recesses. Further, the second engaging portion 85 may be integrally molded with the shaft portion 77. Further, the second engaging portion 85 may be formed so as to have an arc shape (fan shape) when viewed from the Z direction, and the transmission portion may have a plate shape along the radial direction when viewed from the Z direction. ..

The transmission portions 114, 116, the first recesses 118, 122, and the second recesses 124, 126 are not limited to those having a symmetrical arrangement (shape) with respect to the axis, and may be asymmetrical. The first axis and the second axis may be those that rotate in only one direction or those that rotate in both directions. The shaft member 72 and the drive roll 74 may be rotated in the direction opposite to the R direction for the purpose of removing paper dust and the like from the intermediate transfer belt 48. That is, the partition walls 128 and 132 may be used as the transmission unit.

The rotation transmission structure 70 is not limited to the transfer device 30. For example, the rotation transmission structure 70 may be used for coupling the shaft portion of the developing roll for developing the latent image of the photoconductor with the toner T and the rotating shaft for rotating the developing roll. Further, the rotation transmission structure 70 may be used for coupling the shaft portion of the cleaning roll that cleans the outer peripheral surface of the photoconductor and the rotation shaft that rotates the cleaning roll.

10 Image forming device 24 Image forming part (an example of developing agent image forming part)
26 Fixing part 30 Transfer device 48 Intermediate transfer belt (an example of holding member)
52 Secondary transfer roll (an example of transfer member)
54 Drive unit (example of drive source)
56 Power supply unit (example of power supply)
70 Rotation transmission structure 72 Shaft member (an example of the first shaft)
74 Drive roll (an example of the second axis)
76 1st engaging part 84 Transmission member 84C Outer peripheral surface 85 2nd engaging part 112 Attached part 114 Transmission part 116 Transmission part 118 1st concave part 122 1st concave part 124 2nd concave part 126 2nd concave part 134 Blocking part 136 C1 Axial Center C2 Axial Center G Toner Image (Example of Developer Image)
L1 1st length L2 2nd length T toner (example of developer)
W1 1st width W2 2nd width

Claims (11)

The first axis that is driven to rotate,
The second axis to be powered and
A first engaging portion located outside the first axis in the radial direction and rotating integrally with the first axis,
A second engaging portion located outside the second axis in the radial direction and rotating integrally with the second axis,
The first engaging portion and the second engaging portion have a transmission portion sandwiched between the first axis and the second axis in the circumferential direction, and the rotation of the first axis is transferred to the second axis. The resin transmission member and the transmission member
Rotation transmission structure with . The transmission member is formed in a columnar shape, and the transmission portion is arranged at least outside the center position of the axial center of the transmission member and the outer peripheral surface of the transmission member in the transmission member. The rotation transmission structure according to claim 1, which includes a portion. When the transmission portion is viewed from the axial direction of rotation, the first width in the circumferential direction in the radial outer portion of the transmission portion is the circumferential first width in the radial inner portion of the transmission portion. 2. The rotation transmission structure according to claim 1 or 2, which is wider than two widths. The transmission member is
A first recess formed on one side of the circumferential direction with respect to the transmission portion, recessed from one side in the axial direction of rotation toward the other side, and into which the first engaging portion enters.
A second recess formed on the other side in the circumferential direction with respect to the transmission portion, recessed from the other side in the axial direction toward one side, and into which the second engaging portion enters.
An attached portion that is recessed in the axial direction, the first shaft is attached and connected to the first recess, or the second shaft is attached and connected to the second recess .
The rotation transmission structure according to any one of claims 1 to 3. Claims 1 to 4 are formed with a recessed portion formed on the inner side of the transmission portion in the radial direction so as to be recessed on the side away from the first engaging portion or the second engaging portion in the circumferential direction . The rotation transmission structure according to any one of the following items . Claim 1 to claim 1, wherein the transmission member is formed with a blocking portion which is arranged between the first axis and the second axis and cuts off conduction from the second axis to the first axis. 5. The rotation transmission structure according to any one of 5. The first radial length from the center of rotation of the transmission member to the tip of the second engaging portion is the second radial length from the center of rotation to the outer end of the first engaging portion. The rotation transmission structure according to any one of claims 1 to 6 as described above. The rotation transmission structure according to any one of claims 1 to 7, wherein the first engaging portion is made of metal. The rotation transmission structure according to any one of claims 1 to 8.
The drive source that rotates the first axis and
The power supply that supplies power to the second axis and
A holding member that is wound around the second shaft and holds the developer, and
A transfer member provided on the side opposite to the second axis side with respect to the holding member and transferring the developer of the holding member to a recording medium by a potential difference from the second axis.
Transfer device with. The transfer device according to claim 9,
A developer image forming portion that forms a developer image by using a developer on the holding member, and a developer image forming portion.
A fixing unit that fixes the developer transferred to the recording medium to the recording medium,
Image forming apparatus having. It is located on the radial outside of the first shaft that is rotationally driven, and is located on the radial outside of the second shaft that is fed from the first engaging portion that rotates integrally with the first shaft. A resin transmission member that transmits a rotational force to a second engaging portion that rotates integrally with the shaft .
A transmission member having a transmission portion sandwiched between the first engagement portion and the second engagement portion in the circumferential direction of the first axis and the second axis.

Images