JP2008002671A - Rotary drive force coupling device and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotary drive force coupling device capable of preventing the seizure or damage of a meshing tooth by a simple structure, safe, and stable in a rotation property, and capable of forming a recording image of high quality at a low cost even if a deflection angle is generated in a connection part of a driving shaft, and an image forming device equipped with the rotary drive force coupling device. <P>SOLUTION: The rotary drive force coupling device is provided with a drive side coupling part 2 on the driving shaft 1 side for transmitting a rotation drive force, a driven side coupling part 5 on the rotating shaft 4 side of a driven body 3 detachably connected to the drive side connecting part 2, a protruding meshing tooth 6 formed on an outer peripheral surface meshed with a recessed part 60 formed on an inner peripheral surface transmitting the rotation drive force from the drive side coupling part 2 to the driven side coupling part 5, and the tilt surface 8 of a polygonal part 7 formed in the longitudinal direction of the meshing tooth 6. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a rotational driving force coupling device and an image forming apparatus including the rotational driving force coupling device. Specifically, a rotational driving force coupling device that transmits a rotational driving force on the apparatus main body side to a rotating shaft of a driven body that can be attached to and detached from the apparatus main body, and a recording image that includes the rotational driving force coupling device are formed on a recording medium. The present invention relates to an image forming apparatus such as a copying machine, a facsimile machine, a printer, or a complex machine of these.

FIG. 16 is a configuration diagram of an image forming apparatus 1000 including a conventional rotational driving force coupling device 1005.
In FIG. 16, yellow (Y), magenta (M), cyan (C), and black (Bk) photosensitive drums 1110 (Y, M, C, Bk) are driven in tandem to superimpose toner images. 1 shows a general drive train of an image forming apparatus 1000 such as a color printer or a color copier that forms a recorded image.
In such a rotational driving force transmission device 1005 in the image forming apparatus 1000, gears are used for the rotating bodies 1001 (Y, M, C, Bk) corresponding to the respective colors, and the driving gears 1003 (Y, M, C, Bk) are used. And the phase of the gears of the rotating bodies 1001 (Y, M, C, Bk) of the respective colors are adjusted to improve the alignment accuracy of the toner image.

FIG. 17 is a configuration diagram of a driving unit that rotationally drives the photosensitive drum 1110 in the image forming apparatus 1000 with the conventional rotational driving force coupling device 1005.
As shown in FIG. 17, in the image forming apparatus 1000, the photosensitive drum 1110 is driven by a rotation gear 1003, in which a rotation driving force is transmitted by a driving gear 1003 attached to a driving motor 1002. Rotates the drive shaft 1004, and the drive shaft 1004 rotates the photosensitive drum 1110 by rotating the photosensitive drum shaft 1006 via a rotational driving force coupling device 1005 such as a joint. The drive shaft 1004 is supported by a bearing 1007 and positioned and fixed by appropriate means.

FIG. 18 is an exploded cross-sectional view of a conventional rotational driving force coupling device 1005.
FIG. 19 is a side view showing a state in which the pitch circles 1008 of the driving side coupling 1050 and the photosensitive drum shaft side coupling 1051 of the conventional rotational driving force coupling device 1005 are engaged with each other.
FIG. 20 is a graph showing the phase and amplitude characteristics in which rotation unevenness occurs in the photosensitive drum 1110 due to the external load of the image forming apparatus 1000 including the conventional rotational driving force coupling device 1005.
As shown in FIGS. 18 and 19, a driving side coupling 1050 and a photosensitive drum shaft side coupling are coupled to a coupling portion of a rotational driving force coupling device 1005 which is a joint portion of the driving shaft 1004 and the photosensitive drum shaft 1006. Although the engagement of the pitch circles 1008 of 1051 is used, the drive shaft 1004 and the photosensitive drum shaft 1006 in the coupling portion of the driving side coupling 1050 and the photosensitive drum shaft side coupling 1051 of the rotational driving force coupling device 1005 are used. If the axial centers of the photosensitive drums do not coincide with each other, the photosensitive drum 1110 generates rotation unevenness, and the amplitude of each color of black (Bk), yellow (Y), magenta (M), and cyan (C) as shown in the example shown in FIG. The phase changes, the toner image alignment accuracy decreases, and the image quality deteriorates.

FIG. 21 is a cross-sectional view showing a meshed state in which a conventional rotational driving force coupling device 1005 has a declination and the shaft core is displaced.
Further, as shown in FIG. 21, the rotational driving force coupling device 1005 is engaged when the rotational driving force coupling device 1005, which is a joint portion between the driving shaft 1004 and the photosensitive drum shaft 1006, is deviated and the shaft core is displaced. There is also a risk of injury due to galling of the meshing teeth of the coupling portions of the driving side coupling 1050 and the photosensitive drum shaft side coupling 1051.

  Therefore, a detection pattern is formed on the end surface of the drive roller, and a sensor is disposed below the detection pattern. A roller gear is fixed to the roller shaft of the drive roller, and is driven to rotate by a drive motor through the drive gear and coupling. The driving roller diameter is different from the photosensitive drum interval, so that one or more rotations of the driving gear coincide with the interval of the photosensitive drum. Measure the peripheral speed of the drive roller, feed back the signal shifted in phase by 180 ° to the drive motor, rotate it, and move the transfer belt transport belt with the travel speed of the transport belt driven by the drive roller as the ideal speed A device that prevents color misregistration in a tandem type image forming apparatus having a driving roller diameter different from the photosensitive drum interval is known (see Patent Document 1).

  A connecting member is provided on the drive member so as to be movable in the axial direction, and the amount of axial movement of the connecting member is restricted by the axial restricting member, and movement in the rotational direction is restricted by the rotating direction restricting member. Further, an urging means for urging the connecting member so as to abut against the axial restriction member is provided. Furthermore, driven member restricting means for restricting movement of the driven member in the direction of the driving member and positioning for aligning the axis of the driven member with the axis of the driving member are provided. The connecting member is brought into contact with the axial restricting member by the rotation operation of the driving member, and a pressing means for bringing the driven member into contact with at least one of the driving member or the axial restricting member is provided for high-precision rotation. There has also been proposed a drive coupling device having good transmissibility and good operability during attachment / detachment (see Patent Document 2).

  Further, in Patent Document 3, a coupling is also used for rotationally driving a developing roller in an image forming apparatus including a developing device that performs multicolor development. The drive gear swings concentrically with the rotating body, and rotates through the gear and the belt by the driving force of the drive motor. When the rotary gear rotates in the clockwise direction and the drive gear reaches a predetermined position before the position F, the coupling is connected by the cam, and the rotation of the drive gear rotates before reaching the position D where the developing roller contacts the photosensitive member. When the drive gear is at position F, the developing roller is at the developing position D, the rotary is stopped, and development is performed. When the developing roller is separated from the photosensitive member and the driving gear is in the position C by the re-rotation of the rotary, the coupling is released and the rotation of the developing roller is stopped. Accordingly, it has also been proposed that the developing roller is always in contact with and separated from the photosensitive member in a rotating state.

  Furthermore, in order to prevent damage to the coupling of the driven body and damage to the device body, it has a driven side coupling that is connected to the drive side coupling provided on the device body, and is detachable from the device body And both couplings have a plurality of recesses and projections extending in the axial direction and adjacent to each other in the circumferential direction, and the driven cup is provided on the driven body. A protective cover for protecting the ring is provided. The tip of the convex portion in the driven side coupling has a pyramid shape or a conical shape. The protective cover is a cylindrical cover provided on the outer peripheral portion of the driven side coupling, and it has also been proposed that the front end surface thereof is located outward in the axial direction from the front end of the driven side coupling ( (See Patent Document 4).

The cylindrical body is expanded in the outer diameter direction based on the diameter expansion action by the elasticity of the first insertion member and the second insertion member when inserted into the cylindrical body from the end of the cylindrical body. The bearing member fitted to the outer peripheral surface is fastened. The third insertion member is inserted into the first insertion member, and the fourth insertion member is inserted into the second insertion member to improve the deflection accuracy of the cylindrical body such as the electrophotographic photosensitive member. A method and structure for fixing a cylindrical bearing member has also been proposed (see Patent Document 5).
Further, in an electrophotographic color image forming apparatus provided with an image carrier driving device, a projection of a joint member is fitted to the inner end of the image carrier driving shaft, and the image carrier is coupled so as to be able to transmit rotation. It is also known that the image carrier and the image carrier drive shaft are arranged in a straight line (see Patent Document 6).

A photosensitive drum unit of a detachable process cartridge used in an image forming apparatus, a coupling provided on a shaft protruding from one end of the photosensitive drum unit, and a coupling transmits a rotational force from a driving shaft of the image forming apparatus to the photosensitive drum. The coupling has a shape that is uniquely coupled to the main body drive shaft, and the coupling can be coupled in any rotation direction with respect to the protruding shaft of the photosensitive drum, There has also been proposed a process cartridge, a photosensitive drum, and an image forming apparatus which are mounted on the photosensitive drum so as to be in a fixed phase with respect to the minimum peak position, and reduce color misregistration due to rotation unevenness due to drum surface fluctuations ( (See Patent Document 7).
However, at the time of meshing where the shaft axis is displaced due to a declination at the joint of the drive shaft, the meshing teeth can be damaged by galling, and there is a risk of injury, as well as the rotational characteristics change and the rotational drive is unstable. Therefore, there is a problem that the structure is complicated and the cost is high, and the quality of the recorded image formed is lowered.
JP-A-11-184185 Japanese Patent Application Laid-Open No. 2001-100476 JP 2001-134094 A JP 2001-228661 A JP 2001-248656 A JP 2004-109671 A JP 2005-91793 A

In a conventional rotational driving force coupling device and an image forming apparatus equipped with the rotational driving force coupling device, when the engagement is caused by a deviation angle at the joint portion of the drive shaft and the shaft core is displaced, the meshing teeth are galling and damaged. In addition to the risk of injury, there has been a problem in that the rotational characteristics are changed, the rotational drive is unstable, the structure is complicated, the cost is high, and the quality of the recorded image is reduced.
Therefore, an object of the present invention is to solve such problems. In other words, even if a declination occurs at the joint of the drive shaft, it is possible to prevent the occurrence of galling or damage of the meshing teeth, etc. with a simple configuration, and it is safe and stable in rotational characteristics, and can produce high quality recorded images at low cost. It is an object of the present invention to provide a rotational driving force coupling device to be formed and an image forming apparatus including the rotational driving force coupling device.

In order to achieve the above object, the present invention as set forth in claim 1 is directed to a rotational driving force coupling device for transmitting a rotational driving force on the apparatus main body side to a rotating shaft of a driven body detachably attached to the apparatus main body. A driving-side connecting portion on the driving shaft side for transmitting force, a driven-side connecting portion on the rotating shaft side of the driven body detachably connected to the driving-side connecting portion, and the driven-side connecting portion from the driving-side connecting portion A convex meshing tooth formed on the outer peripheral surface that meshes with the concave shaped portion formed on the inner peripheral surface that transmits the rotational driving force, and an inclined surface of the polygonal shaped portion formed in the longitudinal direction of the meshing tooth. It is characterized by.
According to a second aspect of the present invention, in the rotational driving force coupling device according to the first aspect, the driven body includes an image carrier.
According to a third aspect of the present invention, in the rotational driving force coupling device according to the first or second aspect, the meshing teeth are provided in the driving side coupling portion.
According to a fourth aspect of the present invention, in the rotational driving force coupling device according to the first or second aspect, the meshing teeth are provided in the driven side coupling portion.

According to a fifth aspect of the present invention, in the rotational driving force coupling device according to any one of the first to fourth aspects, a plurality of the meshing teeth are provided in the driving side coupling portion or the driven side coupling portion. A sheet is provided.
According to a sixth aspect of the present invention, in the rotational driving force coupling device according to any one of the first to fifth aspects, the polygonal portion of the meshing teeth has a triangular shape.
According to a seventh aspect of the present invention, in the rotational driving force coupling device according to any one of the first to fifth aspects, the polygonal portion of the meshing teeth has a quadrangular shape.
The present invention described in claim 8 is characterized in that, in the rotational driving force coupling device according to any one of claims 1 to 5, the polygonal portion of the meshing teeth is circular.

According to a ninth aspect of the present invention, in the rotational driving force coupling device according to any one of the first to fifth aspects, the polygonal portion of the meshing tooth has an involute shape.
According to a tenth aspect of the present invention, in the rotational driving force coupling device according to any one of the first to ninth aspects, the inclined surface is formed on the front end side in the longitudinal direction of the polygonal portion of the meshing tooth. It is characterized by being.
The present invention according to claim 11 is the rotational driving force coupling device according to any one of claims 1 to 10, wherein the inclined surface is on the rear end side in the longitudinal direction of the polygonal portion of the meshing tooth. It is formed.
According to a twelfth aspect of the present invention, in the rotational driving force coupling device according to any one of the first to eleventh aspects, a plurality of the inclined surfaces are formed to face the polygonal portion of the meshing teeth. It is characterized by being.

According to a thirteenth aspect of the present invention, in the rotational driving force coupling device according to any one of the first to twelfth aspects, the inclined surface angle of the inclined surface is 1 with respect to the longitudinal direction of the meshing teeth. It is characterized by being 3 to 3 degrees.
According to a fourteenth aspect of the present invention, in the rotational driving force coupling device according to any one of the first to thirteenth aspects, the inclined surfaces of the inclined surfaces facing each other with respect to the longitudinal direction of the meshing teeth are opposed to each other. The angle is more than twice the angle of the inclined surface.
According to a fifteenth aspect of the present invention, in the rotational driving force coupling device according to any one of the first to fourteenth aspects, the inclined surface has a curvature surface at an end.
According to a sixteenth aspect of the present invention, in the rotational driving force coupling device according to any one of the first to fifteenth aspects, the driving-side coupling portion and the driven-side coupling portion are rotated by an uneven shape of a tip portion. A rotation center alignment shape portion for aligning the center position is provided.

According to a seventeenth aspect of the present invention, in the rotational driving force coupling device according to the sixteenth aspect, the rotation center alignment shape portion has a concave conical shape and a convex conical shape. And
The present invention according to claim 18 is the rotational driving force coupling device according to claim 17, wherein the conical apex angle of the conical shape on the concave shape side is larger than the conical apex angle of the conical shape on the convex shape side. It is characterized by.
According to a nineteenth aspect of the present invention, in the rotational driving force coupling device of the seventeenth or eighteenth aspect, the conical shape on the concave shape side is on the driving side connecting portion side, and the conical shape on the convex shape side is on the side. It is formed on the driven side connecting portion side.

According to a twentieth aspect of the present invention, in the rotational driving force coupling device according to the seventeenth or eighteenth aspect, the conical shape on the concave shape side is on the driven side coupling portion side, and the conical shape on the convex shape side is on the side. It is formed on the drive side connecting portion side.
According to a twenty-first aspect of the present invention, in the rotational driving force coupling device according to any one of the seventeenth to twentieth aspects, the concave shape side conical shape and the convex shape side of the rotation center alignment shape portion The conical shape is characterized in that it is integrally formed at the tip of the driving side connecting portion or the driven side connecting portion.
According to a twenty-second aspect of the present invention, in the rotational driving force coupling device according to the seventeenth or eighteenth aspect, the conical shape on the concave shape side and the conical shape on the convex shape side of the rotation center alignment shape portion are: It is formed at the tip of the drive shaft or the tip of the rotary shaft.
According to a twenty-third aspect of the present invention, in the rotational driving force coupling device according to the seventeenth or eighteenth aspect, which of the conical shape on the concave shape side and the conical shape on the convex shape side of the rotation center alignment shape portion is selected. One of them is provided with the driving side connecting portion or the driven side connecting portion in an integral shape, and the other is provided at the tip of the drive shaft or the tip of the rotating shaft.

According to a twenty-fourth aspect of the present invention, in the rotational driving force coupling device according to any one of the seventeenth to twenty-third aspects, the depth of the conical shape on the concave shape side is a height of the conical shape on the convex shape side. It is characterized by being smaller.
According to a twenty-fifth aspect of the present invention, in the rotational driving force coupling device according to any one of the seventeenth to twenty-fourth aspects, the conical shape of the convex shape side from the conical apex angle of the conical shape of the concave shape side. The difference between the cone apex angles is larger than the inclined surface facing angle of the inclined surfaces facing each other with respect to the longitudinal direction of the meshing teeth.
According to a twenty-sixth aspect of the present invention, there is provided an image forming apparatus for forming a recorded image on a recording medium, an image forming unit for forming a recorded image on the recording medium, and any one of the first to twenty-fifth aspects. The rotational driving force coupling device described above is provided.

  According to the present invention, even if a declination occurs in the joint portion of the drive shaft, it is possible to prevent the occurrence of galling or damage of the meshing teeth etc. with a simple configuration, and it is safe and stable in the rotational characteristics and high quality at a low cost. The rotational driving force coupling device for forming the recorded image and the image forming apparatus including the rotational driving force coupling device can be provided.

Embodiments of the present invention will be described below in detail with reference to the drawings.
FIG. 1 is a perspective view showing a configuration of a rotational driving force coupling device 10 of the present embodiment.
FIG. 2 is a side view showing a normal meshing state of the meshing teeth 6 of the rotational driving force coupling device 10 of the present embodiment.
FIG. 3 is a configuration diagram of the polygonal portion 7 when the meshing teeth 6 of the rotational driving force coupling device 10 of the present embodiment are viewed from the direction of the arrow A in the section XX in FIG.
FIG. 4 is a side view showing a meshing state in which a declination is generated in the meshing teeth 6 of the rotational driving force coupling device 10 of the present embodiment and the axis is displaced.

  In FIG. 1, a rotational driving force coupling device 10 that transmits a rotational driving force on the apparatus main body side to a rotating shaft of a driven body that can be attached to and detached from the apparatus main body includes a driving side coupling portion on the driving shaft 1 side that transmits the rotational driving force. 2, a driven side connecting portion 5 on the rotating shaft 4 side of the image bearing member 110 of the photosensitive drum which is a driven body 3 detachably connected to the driving side connecting portion 2, and a driven side connecting portion from the driving side connecting portion 2. A convex meshing tooth 6 formed on the outer peripheral surface meshing with the concave shaped portion 60 formed on the inner peripheral surface for transmitting the rotational driving force to the part 5 and a plane of the polygonal shaped part 7 formed in the longitudinal direction of the meshing tooth 6 or An inclined surface 8 made of a curved surface is provided.

The meshing tooth 6 and the concave shaped portion 60 are meshed at two or more locations, and in the drawing, by meshing four, the driving-side connecting portion 2 and the rotating shaft 4 on the driving shaft 1 side without increasing the width of the meshing teeth 6. By engaging the driven side connecting portion 5 on the side, the rotational driving force can be more reliably transmitted to the driven body 3 side.
The drive shaft 1 and the rotary shaft 4 are both cut with metal, which is desirable for further improving accuracy.
Although the meshing teeth 6 are provided in the driven side connecting portion 5 as shown in the figure, they may be provided in the driving side connecting portion 2 although not shown.
Further, the rotational driving force coupling device 10 rotates the position of the center of rotation by the conical shape 90 on the concave shape side and the conical shape 91 on the convex shape side formed at the distal end portions of the driving side coupling portion 2 and the driven side coupling portion 5. A center alignment shape portion 9 is provided.

2, the rotational driving force coupling device 10 is a side view of the rotating shaft 4 side showing a normal meshing state between the meshing tooth 6 and the concave portion 60, and the meshing tooth 6 is shown in FIG. Four are provided.
In the rotational driving force coupling device 10, the meshing of the gears is not limited by the concept that the pitch circles mesh with each other, and if the meshing teeth 6 and the concave portion 60 are in contact with each other and the torque is transmitted, the rotation is possible. The rotational driving force can be transmitted in a state where the eccentricity of the shaft 4 is small.

FIG. 3 is a schematic diagram when the hexagonal shape of the meshing teeth 6 is viewed from directly above when the polygonal portion 7 is observed from the direction of the arrow A of the XX cross section in FIG. 2.
The polygonal portion 7 is not limited to a hexagonal shape, and a triangular shape, a quadrangular shape, a pentagonal shape, a heptagonal shape, an octagonal shape, a nine-sided shape, a decagonal shape,..., And a circular shape and an involute shape are also used. However, even-numbered squares are excellent in terms of balance.
The inclined surface 8 which consists of a plane or a curved surface is provided with two or more facing the polygonal part 7 in the front end side and the rear end side of the polygonal part 7 of the meshing tooth 6 in the longitudinal direction.
At this time, the inclined surface angle θ1 of the inclined surface 8 of the polygonal portion 7 is set to 1 to 3 degrees with respect to the longitudinal direction of the meshing tooth 6 in the direction of the arrow B shown in the drawing, so that the drive side on the drive shaft 1 side Even if a declination occurs in the meshing between the coupling portion 2 and the driven-side coupling portion 5 on the rotating shaft 4 side, the assembling property is improved. And smooth rotation characteristics can be obtained.

The inclined surface facing angle θ2 of the inclined surfaces 8 facing each other with respect to the longitudinal direction of the meshing tooth 6 in the direction of the arrow B shown in the drawing is at least twice as large as the inclined surface angle θ1, so that the thickness Y of the meshing tooth 6 is increased. And the strength can be secured and the optimum shape related to the meshing part can be obtained.
In the rotational driving force coupling device 10, depending on the material and thickness of the driving shaft 1, the rotating shaft 4, the meshing teeth 6, etc., the driving side coupling portion 2 on the driving shaft 1 side and the driven side coupling on the rotating shaft 4 side. When rotating with the torque 7N with which the meshing tooth 6 meshes with the concave shaped part 60 of the part 5, the rotation is transmitted with the eccentricity of the rotating shaft 4 being small when the meshing tooth 6 is meshed with the thickness Y = 3 mm or more. Was made.
Furthermore, these inclined surfaces 8 are provided with a curvature surface 80 at the end, thereby preventing the occurrence of damage or the like and further safety.

  As shown in FIG. 4, in the rotational driving force coupling device 10, a concave meshing with the meshing tooth 6 with respect to the wall thickness Y of the meshing tooth 6 even when the meshing tooth 6 has a declination and the shaft center is shifted. The groove width Z of the shape portion 60 is such that the thickness Y of the meshing teeth 6 is smaller than the groove width Z of the concave shape portion 60, and a clearance is generated in the gap of the concave shape portion 60 that meshes with the meshing teeth 6.

FIG. 5 is a configuration diagram of the triangular shape 70 of the polygonal portion 7 when the meshing teeth 6 of the rotational driving force coupling device 10 of the present embodiment are viewed from the direction of the arrow A in the section XX in FIG.
In FIG. 5, when the polygonal portion 7 is observed from the direction of the arrow A of the XX cross section in FIG. 2, a schematic view when the triangular shape 70 of the meshing tooth 6 that is easy to mold at low cost is viewed from directly above. FIG. The inclined surface 8 made of a plane or curved surface that is easy to mold at a low cost of the triangular shape 70 is formed into a triangular shape 70 on the front end side and the rear end side in the longitudinal direction of the triangular shape 70 of the meshing tooth 6 in the illustrated arrow B direction. A plurality are provided facing each other.
By setting the inclined surface angle θ1 of the illustrated inclined surface 8 of the triangular shape 70 to 1 to 3 degrees with respect to the longitudinal direction of the meshing tooth 6 in the illustrated arrow B direction, the drive side connecting portion on the drive shaft 1 side. 2 and the driven side connecting portion 5 on the rotating shaft 4 side, even if a declination occurs, the assemblability is improved and the engagement teeth 6 are not normally galvanized, and an appropriate fitting clearance is always secured. Smooth rotation characteristics can be obtained.

By making the inclined surface facing angle θ2 of the inclined surfaces 8 facing each other with respect to the longitudinal direction of the meshing teeth 6 in the direction of the arrow B shown in the figure, the thickness Y of the meshing teeth 6 is set to at least twice the inclined surface angle θ1. And strength can be secured.
Further, the inclined surface 8 of the triangular shape 70 is provided with a curvature surface 80 at the end portion, thereby preventing the occurrence of damage and the like and further safety.
Therefore, even if a declination occurs at the joint portion of the drive shaft 1, the simple configuration of the triangular shape 70 prevents the meshing teeth 6 from being galled or damaged, and is safe and stable in rotational characteristics. A costly rotational driving force coupling device 10 can be provided.

FIG. 6 is a configuration diagram of a quadrangular shape 71 of the polygonal portion 7 when the meshing teeth 6 of the rotational driving force coupling device 10 of the present embodiment are viewed from the direction of the arrow A in the section XX in FIG.
6, when the polygonal portion 7 is observed from the direction of the arrow A of the XX cross section in FIG. 2, a schematic view when the rectangular shape 71 of the meshing tooth 6 that is easy to mold at low cost is viewed from directly above. FIG. The inclined surface 8 made of a flat surface or a curved surface, which is easy to mold at a low cost, is formed into a rectangular shape 71 on the front end side and the rear end side in the longitudinal direction of the quadrilateral shape 71 of the meshing tooth 6 in the illustrated arrow B direction. A plurality are provided facing each other.
By setting the inclined surface angle θ1 of the illustrated inclined surface 8 of the quadrangular shape 71 to 1 to 3 degrees with respect to the longitudinal direction of the meshing tooth 6 in the direction of the arrow B shown in the drawing, the drive side connecting portion on the drive shaft 1 side 2 and the driven side connecting portion 5 on the rotating shaft 4 side, even if a declination occurs, the assemblability is improved and the engagement teeth 6 are not normally galvanized, and an appropriate fitting clearance is always secured. Smooth rotation characteristics can be obtained.

By making the inclined surface facing angle θ2 of the inclined surfaces 8 facing each other with respect to the longitudinal direction of the meshing teeth 6 in the direction of the arrow B shown in the figure, the thickness Y of the meshing teeth 6 is set to at least twice the inclined surface angle θ1. And strength can be secured.
Further, the inclined surface 8 of the quadrangular shape 71 is provided with a curvature surface 80 at the end portion, thereby preventing the occurrence of damage and the like and further safety.
Therefore, even if a declination occurs at the joint portion of the drive shaft 1, the simple configuration of the rectangular shape 71 prevents the meshing teeth 6 from galling, damage, etc., and it is safe and stable in rotational characteristics. A costly rotational driving force coupling device 10 can be provided.

FIG. 7 is a diagram of a circular shape 72 made up of a number of angular shapes of polygonal portions 7 when the meshing teeth 6 of the rotational driving force coupling device 10 of the present embodiment are viewed from the direction of the arrow A in the section XX in FIG. It is a block diagram.
In FIG. 7, when the polygonal portion 7 is observed from the direction of the arrow A of the XX cross section in FIG. 2, the circular shape 72 made up of a number of square shapes that are easy to mold at a low cost of the meshing teeth 6 is true. It is a schematic diagram when seen from above. The inclined surface 8 made of a flat surface or curved surface, which is easy to mold at a low cost, of the circular shape 72 made up of many square shapes, is the front end side and the rear end in the longitudinal direction of the circular shape 72 of the meshing tooth 6 in the direction indicated by the arrow B A plurality is provided on the side facing the circular shape 72.
By setting the inclined surface angle θ1 of the illustrated inclined surface 8 of the circular shape 72 to 1 to 3 degrees with respect to the longitudinal direction of the meshing tooth 6 in the illustrated arrow B direction, the drive side connecting portion on the drive shaft 1 side is set. 2 and the driven-side connecting portion 5 on the rotating shaft 4 side, even if a declination occurs, the assemblability is improved and the engagement teeth 6 are not normally galling, and an appropriate fitting clearance is always secured. Smooth rotation characteristics can be obtained.

By making the inclined surface facing angle θ2 of the inclined surfaces 8 facing each other with respect to the longitudinal direction of the meshing teeth 6 in the direction of the arrow B shown in the figure, the thickness Y of the meshing teeth 6 is set to at least twice the inclined surface angle θ1. And strength can be secured.
Furthermore, the inclined surface 8 of the circular shape 72 is provided with a curvature surface 80 at the end portion, thereby preventing the occurrence of damage and the like and further safety.
Therefore, even if a declination occurs at the joint portion of the drive shaft 1, the simple structure comprising the circular shape 72 prevents the meshing teeth 6 from being galled or damaged, and is safe and stable in rotation characteristics. A costly rotational driving force coupling device 10 can be provided.

FIG. 8 is a configuration diagram of the involute shape 73 of the polygonal portion 7 when the meshing teeth 6 of the rotational driving force coupling device 10 of the present embodiment are viewed from the direction of the arrow A in the XX cross section in FIG.
In FIG. 8, when the involute shape 73 that is easy to mold at low cost of the meshing tooth 6 is viewed from directly above when the polygonal portion 7 is observed from the direction of the arrow A of the XX cross section in FIG. 2. FIG. The inclined surface 8 formed of a flat surface or a curved surface of the involute shape 73 which is easy to mold at low cost is provided on the front end side and the rear end side in the longitudinal direction of the involute shape 73 of the meshing tooth 6 in the illustrated arrow B direction. A plurality is provided opposite to the volute shape 73.
By setting the inclined surface angle θ1 of the illustrated inclined surface 8 of the involute shape 73 to 1 to 3 degrees with respect to the longitudinal direction of the meshing tooth 6 in the illustrated arrow B direction, the drive side on the drive shaft 1 side is set. Even if a declination occurs in the meshing between the coupling part 2 and the driven-side coupling part 5 on the rotating shaft 4 side, the assemblability is improved and the meshing teeth 6 are not normally galvanized, and an appropriate fitting gap is always provided. And smooth rotation characteristics can be obtained.

By making the inclined surface facing angle θ2 of the inclined surfaces 8 facing each other with respect to the longitudinal direction of the meshing teeth 6 in the direction of the arrow B shown in the figure, the thickness Y of the meshing teeth 6 is set to at least twice the inclined surface angle θ1. And strength can be secured.
Further, the inclined surface 8 of the involute shape 73 is provided with a curvature surface 80 at the end portion, thereby preventing the occurrence of damage and the like and further safety.
Therefore, even if a declination occurs at the joint portion of the drive shaft 1, the simple configuration comprising the involute shape 73 prevents the biting or damage of the meshing teeth 6, which is safe and stable in rotation characteristics. Furthermore, the low cost rotational driving force coupling device 10 can be provided.

FIG. 9 is a cross-sectional view of the rotational center alignment shape portion 9 of the rotational driving force coupling device 10 of the present embodiment.
In FIG. 9, the rotation center alignment by the concavo-convex shape of the rotation center alignment shape portion 9 in the rotational driving force coupling device 10 is integrally formed at the distal end portions of the drive side connection portion 2 and the driven side connection portion 5. The conical shape 90 of the concave shape side and the conical shape 91 of the convex shape side are configured such that the conical vertex angle θ3 of the conical shape 90 of the concave shape side is larger than the conical vertex angle θ4 of the conical shape 91 of the convex shape side (θ3 > Θ4) The depth C of the conical shape 90 on the concave shape side is smaller than the height D of the conical shape 91 on the convex shape side and shallower (C <D), so that the drive shaft 1 and the rotary shaft 4 are joined. The amplitude at the time of meshing due to the mutual misalignment of the shaft center at the portion can be reduced, and the drive side connecting portion 2 on the drive shaft 1 side and the driven side connecting portion 5 on the rotating shaft 4 side can be easily attached and detached, Conical shape facilitates processing of the shape, and conical shape on the concave side 90 and convex side of the conical 91 apexes reliably contact of allowing rotation center aligned together well the axis accuracy.

The difference (θ3-θ4) between the cone apex angle θ3 of the conical shape 90 on the concave side and the cone apex angle θ4 of the conical shape 91 on the convex shape side is the inclined surfaces 8 facing each other with respect to the longitudinal direction of the meshing teeth 6. By setting the angle to be larger than the inclined surface facing angle θ 2, an optimum shape is obtained in which the meshing portion of the meshing tooth 6 has a margin.
Furthermore, the conical shape 90 on the concave shape side and the conical shape 91 on the convex shape side of the rotation center alignment shape portion 9 are integrally formed with the driving side connecting portion 2 and the driven side connecting portion 5, so that the driving shaft 1 and The rotary shaft 4 can be short, and it is possible to provide the rotational driving force coupling device 10 that can reduce cost and improve assemblability because it can be easily manufactured by a mold.

FIG. 10 shows the conical shape 90 on the concave side constituting the rotational center alignment shape portion 9 of the rotational driving force coupling device 10 of the present embodiment as the tip of the drive shaft 1 and the conical shape 91 on the convex side as the rotational axis. 4 is a cross-sectional view formed to remain at the tip of 4. FIG.
In FIG. 10, the rotation center alignment shape portion 9 in the rotational driving force coupling device 10 has a conical shape on the convex shape side at the tip of the drive shaft 1 that fits the conical shape 90 on the concave shape side to the drive side coupling portion 2. 91 is provided at the tip of the rotating shaft 4 that is fitted to the driven side connecting portion 5.
Therefore, the rotational driving force coupling device 10 that improves the accuracy and durability of the fitting portion can be provided.

FIG. 11 shows that the conical shape 90 on the concave shape side constituting the rotational center alignment shape portion 9 of the rotational driving force coupling device 10 of the present embodiment is on the rotating shaft 4 side, and the conical shape 91 on the convex shape side is the driving shaft 1. It is sectional drawing formed leaving behind.
In FIG. 11, the rotational center alignment shape portion 9 in the rotational driving force coupling device 10 has a conical shape on the convex shape side at the tip of the rotating shaft 4 that fits the concave shape conical shape 90 to the driven side coupling portion 5. 91 is provided at the tip of the drive shaft 1 which is fitted to the drive side connecting portion 2.
Therefore, the rotational driving force coupling device 10 that improves the accuracy and durability of the fitting portion can be provided.

FIG. 12 shows that the conical shape 90 on the concave shape side constituting the rotational center alignment shape portion 9 of the rotational driving force coupling device 10 of the present embodiment is driven in the drive side connecting portion 2 and the conical shape 91 on the convex shape side is driven. FIG. 6 is a cross-sectional view formed by leaving the tip of the side connecting portion 5.
In FIG. 12, the rotational center alignment shape portion 9 in the rotational driving force coupling device 10 rotates the conical shape 90 on the convex shape side into the conical shape 90 on the concave shape side, and the conical shape 91 on the convex shape side. An integrated shape is provided at the tip of the driven side connecting portion 5 on the shaft 4 side.
Therefore, the conical shape 90 on the concave shape side and the conical shape 91 on the convex shape side of the rotation center alignment shape portion 9 are integrally formed with the drive side connecting portion 2 and the driven side connecting portion 5. It is possible to provide the rotational driving force coupling device 10 that can reduce the cost and assemblability, improve the accuracy of the fitting portion, and improve the durability because the rotating shaft 4 may be short and can be easily manufactured by a mold. .

FIG. 13 shows a concave conical shape 90 constituting the rotational center alignment shape portion 9 of the rotational driving force coupling device 10 of the present embodiment, and a convex conical shape 91 on the distal end of the driven side coupling portion 5. FIG. 4 is a cross-sectional view formed in the drive side connecting portion 2 while remaining.
In FIG. 13, the rotational center alignment shape portion 9 in the rotational driving force coupling device 10 has a conical shape 90 on the concave side at the tip of the driven side coupling portion 5 on the rotating shaft 4 side, and a conical shape 91 on the convex shape side. Are integrally formed in the drive side connecting portion 2 on the drive shaft 1 side.
Therefore, the conical shape 90 on the concave shape side and the conical shape 91 on the convex shape side of the rotation center alignment shape portion 9 are integrally formed with the drive side connecting portion 2 and the driven side connecting portion 5. It is possible to provide the rotational driving force coupling device 10 that can reduce the cost and assemblability, improve the accuracy of the fitting portion, and improve the durability because the rotating shaft 4 may be short and can be easily manufactured by a mold. .

Note that either the conical shape 90 on the concave shape side or the conical shape 91 on the convex shape side of the rotation center alignment shape portion 9 is the drive side connecting portion 2 or the driven side connecting portion as shown in FIG. It is provided in an integral shape with the part 5 and the other side is provided at the tip of the drive shaft 1 or the tip of the rotary shaft 4 as shown in FIG. 10 or FIG. It is possible to provide the rotational driving force coupling device 10 that can select a combination in an advantageous shape each time.
Accordingly, it is possible to provide a rotational driving force coupling device 10 that forms a high-quality recorded image at a low cost by preventing the occurrence of galling or damage of the meshing teeth 6 and the like with a simple configuration, being safe and having stable rotational characteristics. I can do it.

FIG. 14 is a configuration diagram of the image forming apparatus 100 including the rotational driving force coupling device 10 of the present embodiment.
FIG. 15 is a graph showing the phase and amplitude characteristics of each color in the image forming apparatus 100 including the rotational driving force coupling device 10 of the present embodiment.
14, the image forming apparatus 100 that forms a recorded image on a recording medium rotates the image forming unit 101 that forms a recorded image on a recording sheet of the recording medium P, and the image carrier 110. Thru | or the said rotational driving force connection apparatus 10 as described in any one of 25.
The image forming apparatus 100 sequentially writes and forms different images on a plurality of image carriers 110 and then transfers the images onto a recording sheet of a recording medium P to be discharged on the upper part of an image forming unit 101 that forms a color recording image. A paper tray 102 is mounted, and the image forming unit 101 is held above the recording medium feeding unit 103.

The image forming unit 101 tandemly drives a photosensitive drum 110 (Y, M, C, Bk) as an image carrier 110 of each color of yellow (Y), magenta (M), cyan (C), and black (Bk). Then, the recorded images are formed by superimposing the toner images.
It has an intermediate transfer belt 112 as an intermediate transfer body, and a photosensitive drum 110 (Y) as an image carrier 110 and a photosensitive drum 110 (M) along the direction of the arrow (E) shown in the movement direction. The image forming stations including the photosensitive drum 110 (C) and the photosensitive drum 110 (Bk) are arranged in parallel. In each image forming station having the photosensitive drums 110 (Y), 110 (M), 110 (C), and 110 (Bk), yellow (Y), magenta (M), cyan (C), and black (Bk) toners are used. Each image is formed.

The image forming station that forms a yellow (Y) toner image will be described as a representative example. The photosensitive drum 110 (Y) that is rotationally driven through the rotational driving force coupling device 10 by the rotational driving force of a driving motor (not shown). Around the charging roller 113 (Y) for uniformly charging the surface of the photosensitive drum 110 (Y), writing means 114 (Y) for writing different images (images for each color separation), writing means 114 A developing unit 115 (Y) having a developing roller that attaches a charged toner to the electrostatic latent image formed by (Y) and visualizes it, and a photosensitive drum 110 (provided inside the intermediate transfer belt 112). Y) A primary transfer roller 116 (Y) for primarily transferring the toner image on the intermediate transfer belt 112, and scraping off the toner remaining on the photosensitive drum 110 (Y) after the transfer. The cleaning unit 117 (Y) are arranged.
Since the other image forming stations have the same configuration, they are distinguished by adding European characters for each color, and description thereof is omitted.

  In the image forming apparatus 100, the photosensitive drums 110 (Y, M, C, and Bk) are uniformly charged by the charging rollers 113 (Y, M, C, and Bk), and then the writing unit 114 (Y, M, and C). , Bk), an image for each color separation is written to form an electrostatic latent image, and the latent image is developed by a developing unit 115 (Y, M, C, Bk) that holds toner of each color. The toner images of the respective colors are sequentially superposed on the intermediate transfer belt 112 by the primary transfer rollers 116 (Y, M, C, Bk) and are primarily transferred, and the toner image on the intermediate transfer belt 112 is secondarily transferred by the secondary transfer roller 118. The subsequent recording medium (P) is conveyed to the fixing device 119, and the toner image is fixed on the recording medium (P) to form a color recording image or a multicolor recording image. The paper discharge roller 121 Is housed is discharged to.

As shown in FIG. 15, in the image forming apparatus 100 including the rotational driving force coupling device 10, the phase and amplitude fluctuations of each color yellow (Y), magenta (M), cyan (C), and black (Bk) are reduced, and the toner is reduced. Image alignment accuracy is improved.
Therefore, even if a declination occurs at the joint of the drive shaft, it is possible to prevent the occurrence of galling or damage of the meshing teeth etc. with a simple structure, and it is safe and stable in the rotation characteristics, and can produce high quality recorded images at low cost. An image forming apparatus 100 including the rotational driving force coupling device 10 to be formed can be provided.

It is a perspective view which shows the structure of the rotational driving force connection apparatus of this embodiment. It is a side view which shows the normal meshing state of the meshing tooth of the rotational driving force coupling device of this embodiment. It is a block diagram of the polygonal part which looked at the meshing tooth of the rotational driving force coupling device of this embodiment from the arrow A direction of the XX cross section in FIG. It is a side view which shows the meshing state which the declination produced in the meshing tooth of the rotational driving force coupling device of this embodiment, and the shaft center shifted | deviated. It is the figure which looked at the meshing tooth | gear of the rotational driving force coupling device of this embodiment from the arrow A direction of the XX cross section. It is the figure which looked at the meshing tooth | gear of the rotational driving force coupling device of this embodiment from the arrow A direction of the XX cross section. It is the figure which looked at the meshing tooth | gear of the rotational driving force coupling device of this embodiment from the arrow A direction of the XX cross section. It is the figure which looked at the meshing tooth | gear of the rotational driving force coupling device of this embodiment from the arrow A direction of the XX cross section. It is sectional drawing of the rotation center alignment shape part of the rotational driving force connection apparatus of this embodiment. FIG. 6 is a cross-sectional view of a concave conical shape that forms the rotational center alignment shape portion of the rotational driving force coupling device of the present embodiment, with the convex cone side remaining on the distal end of the rotational shaft. is there. It is sectional drawing which shows the structure of the rotation center alignment shape part of the rotational driving force connection apparatus of this embodiment. It is sectional drawing which shows the structure of the rotation center alignment shape part of the rotational driving force connection apparatus of this embodiment. It is sectional drawing which shows the structure of the rotation center alignment shape part of the rotational driving force connection apparatus of this embodiment. It is a block diagram of an image forming apparatus provided with the rotational driving force coupling device of this embodiment. FIG. 6 is a graph showing the phase and amplitude characteristics of each color in an image forming apparatus including the rotational driving force coupling device of the present embodiment. It is a block diagram of an image forming apparatus provided with the conventional rotational driving force connection apparatus. It is a block diagram of rotationally driving a photosensitive drum in an image forming apparatus with a conventional rotational driving force coupling device. It is a disassembled sectional view of the conventional rotational driving force coupling device. It is a side view which shows the meshing state of the pitch circles of the drive side coupling and the photosensitive drum shaft side coupling of the conventional rotational driving force coupling device. FIG. 10 is a graph showing characteristics of phase and amplitude at which rotation unevenness occurs on a photosensitive drum due to an external load of an image forming apparatus including a conventional rotational driving force coupling device. It is sectional drawing which shows the meshing state which a declination produced in the conventional rotational drive force coupling device, and the shaft center shifted | deviated.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Drive shaft, 2 Drive side connection part, 3 Driven body, 4 Rotating shaft, 5 Driven side connection part, 6 Engagement tooth, 7 Polygon-shaped part, 8 Inclined surface, 9 Rotation center alignment shape part, 10 Rotation drive Force coupling device, 60 concave shape portion, 70 triangular shape, 71 square shape, 72 circular shape, 73 involute shape, 80 curvature surface, 90 concave shape side conical shape, 91 convex shape side conical shape, 100 image forming device, DESCRIPTION OF SYMBOLS 101 Image forming unit, 102 Paper discharge tray, 103 Recording medium feeding unit, 110 Image carrier, 110 (Y, M, C, Bk) Photosensitive drum, 112 Intermediate transfer belt, 113 (Y, M, C, Bk) Charging roller, 114 (Y, M, C, Bk) Writing means, 115 (Y, M, C, Bk) Development unit, 116 (Y, M, C, Bk) Primary transfer roller, 117 ( Y, M, C, Bk) Cleaning unit, 118 Secondary transfer roller, 119 Fixing device, 120 Conveying path, 121 Paper discharge roller, 1000 Image forming device, 1001 (Y, M, C, Bk) Rotating body, 1002 Drive Motor, 1003 (Y, M, C, Bk) Drive gear, 1004 Drive shaft, 1005 Rotation drive force coupling device, 1006 Photoconductor drum shaft, 1007 Bearing, 1008 Pitch circle, 1050 Drive side coupling, 1051 Photoconductor drum shaft Side coupling, 1110 (Y, M, C, Bk) Photosensitive drum

Claims (26)

  In a rotational driving force coupling device that transmits a rotational driving force on the apparatus main body to a rotating shaft of a driven body that can be attached to and detached from the apparatus main body, a driving side coupling portion on the driving shaft that transmits the rotational driving force, and the driving side coupling A driven-side connecting portion on the rotating shaft side of a driven body that is detachably connected to the portion, and a concave-shaped portion formed on an inner peripheral surface that transmits rotational driving force from the driving-side connecting portion to the driven-side connecting portion. A rotational driving force coupling device comprising a convex meshing tooth formed on an outer peripheral surface and an inclined surface of a polygonal portion formed in a longitudinal direction of the meshing tooth.   The rotational driving force coupling device according to claim 1, wherein the driven body includes an image carrier.   The rotational driving force coupling device according to claim 1, wherein the meshing teeth are provided in the driving side coupling portion.   The rotational driving force coupling device according to claim 1, wherein the meshing teeth are provided in the driven side coupling portion.   The rotational driving force coupling device according to any one of claims 1 to 4, wherein the meshing teeth include a plurality of teeth on the driving side coupling portion or the driven side coupling portion. Power coupling device.   The rotational driving force coupling device according to any one of claims 1 to 5, wherein the polygonal portion of the meshing teeth has a triangular shape.   The rotational driving force coupling device according to any one of claims 1 to 5, wherein the polygonal portion of the meshing teeth has a quadrangular shape.   The rotational driving force coupling device according to any one of claims 1 to 5, wherein the polygonal portion of the meshing teeth is circular.   The rotational driving force coupling device according to any one of claims 1 to 5, wherein the polygonal portion of the meshing tooth has an involute shape.   The rotational driving force coupling device according to any one of claims 1 to 9, wherein the inclined surface is formed on a front end side in a longitudinal direction of a polygonal portion of the meshing teeth. Power coupling device.   The rotation driving force coupling device according to any one of claims 1 to 10, wherein the inclined surface is formed on a rear end side in a longitudinal direction of a polygonal portion of the meshing teeth. Driving force coupling device.   The rotational driving force coupling device according to any one of claims 1 to 11, wherein a plurality of the inclined surfaces are formed to face a polygonal portion of the meshing teeth. apparatus.   The rotational driving force coupling device according to any one of claims 1 to 12, wherein an inclined surface angle of the inclined surface is 1 to 3 degrees with respect to a longitudinal direction of the meshing teeth. Rotational driving force coupling device.   14. The rotational driving force coupling device according to claim 1, wherein an inclined surface facing angle of the inclined surfaces facing each other with respect to the longitudinal direction of the meshing teeth is twice or more of the inclined surface angle. There is provided a rotational driving force coupling device.   The rotational driving force coupling device according to claim 1, wherein the inclined surface has a curvature surface at an end.   The rotational driving force coupling device according to any one of claims 1 to 15, wherein the driving-side coupling portion and the driven-side coupling portion have a rotational center alignment shape that aligns a rotational center position by an uneven shape of a tip portion. A rotational driving force coupling device comprising a portion.   17. The rotational driving force coupling device according to claim 16, wherein the rotation center alignment shape portion has a concave conical shape and a convex conical shape.   18. The rotational driving force coupling device according to claim 17, wherein a conical apex angle of the conical shape on the concave shape side is larger than a conical apex angle of the conical shape on the convex shape side.   The rotational driving force coupling device according to claim 17 or 18, wherein the conical shape on the concave shape side is formed on the driving side coupling portion side, and the conical shape on the convex shape side is formed on the driven side coupling portion side. A rotational driving force coupling device.   The rotational driving force coupling device according to claim 17 or 18, wherein the conical shape on the concave shape side is formed on the driven side coupling portion side, and the conical shape on the convex shape side is formed on the driving side coupling portion side. A rotational driving force coupling device.   The rotational driving force coupling device according to any one of claims 17 to 20, wherein the conical shape on the concave shape side and the conical shape on the convex shape side of the rotational center alignment shape portion are the drive side coupling portion. Alternatively, the rotational driving force coupling device is formed integrally with the distal end portion of the driven side coupling portion.   The rotational driving force coupling device according to claim 17 or 18, wherein the conical shape on the concave shape side and the conical shape on the convex shape side of the rotational center alignment shape portion are the tip of the drive shaft or the rotational shaft. A rotational driving force coupling device formed at the tip.   19. The rotational driving force coupling device according to claim 17, wherein either the conical shape on the concave shape side or the conical shape on the convex shape side of the rotational center alignment shape portion is the driving side coupling portion or the A rotational driving force coupling device comprising a driven side coupling portion in an integral shape, the other of which is provided at the tip of the drive shaft or the tip of the rotary shaft.   24. The rotational driving force coupling device according to claim 17, wherein a depth of the conical shape on the concave shape side is smaller than a height of the conical shape on the convex shape side. Connecting device.   The rotational driving force coupling device according to any one of claims 17 to 24, wherein a difference between a conical apex angle of the conical shape on the concave shape side and a conical apex angle of the conical shape on the convex shape side is the meshing. A rotational driving force coupling device characterized in that it is larger than an inclined surface facing angle of inclined surfaces facing each other with respect to the longitudinal direction of the teeth.   An image forming apparatus for forming a recorded image on a recording medium, comprising: an image forming unit for forming a recorded image on a recording medium; and the rotational driving force coupling device according to any one of claims 1 to 25. An image forming apparatus.

Images