JP4632412B2 - Drive device for image forming apparatus. - Google Patents

Description

  The present invention relates to a drive device for an image forming apparatus, and more particularly, to a drive device for an image forming apparatus for driving a drive unit disposed inside an image forming apparatus body.

As shown in FIGS. 1 to 5, a conventional driving device of an image forming apparatus includes a driving device case 101, a driving unit 102, a driving force transmission mechanism 103, and a connecting member 104. .
The drive device case 101 includes a case main body 101a and a support portion 101b. The case body 101a is integrally formed with first and second gear bearings 101c and 101d that support first and second idle gear shafts 113a and 123a, which will be described later, in a non-rotatable manner. The first and second gear bearings 101c and 101d are formed so as to protrude inward of the case main body 101a. The support portion 101b is attached to the case main body 101a by a screw member such as a bolt or a screw. The support portion 101b is formed in a U shape. Through holes 101e are formed in the plate-like portions of the support portion 101b facing each other.

The drive means 102 is, for example, a drive motor 102, and is fixed to the case main body 101a by a screw member such as a bolt or a screw. The drive motor 102 includes a drive gear 102b which is rotatably mounted on the rotary shaft 102a and the rotating shaft 102a that outputs a rotational driving force.
The driving force transmission mechanism 103 includes a first idle gear portion 113 and a second idle gear portion 123. The first idle gear unit 113 includes a first idle gear shaft 113a and a first idle gear 113b. The first idle gear shaft 113a is non-rotatably mounted on the first gear bearing 101c of the case body 101a. The first idle gear 113b is rotatably mounted on the first idle gear shaft 113a and meshes with the drive gear 102b. The second idle gear unit 123 includes a second idle gear shaft 123a and a second idle gear 123b. The second idle gear shaft 123a is non-rotatably mounted on the second gear bearing 101d of the case body 101a. The second idle gear 123b is rotatably mounted on the second idle gear shaft 123a and meshes with the first idle gear 113b.

  The connecting member 104 has a connecting shaft 104a and a connecting shaft gear 104b. The connecting shaft 104a has a connecting portion 104c that can be connected to the drive portion at one end. The connection part 104c has the groove part 204 formed in the concave shape. The connecting portion 104c is formed in a cylindrical shape, and the groove portion 204 is provided on the inner peripheral portion of the connecting portion 104c. The groove part 204 has a pair of opposed wall parts 204a and a bottom part 204b provided between the pair of wall parts 204a. The wall portion 204a includes a surface 204c that is formed perpendicular to the rotation axis of the connecting shaft 104a at a predetermined distance from the bottom portion 204b. That is, a step is generated between the surface 204c and the bottom portion 204b. The connecting shaft 104a is inserted through the through hole 101e of the support portion 101b of the case main body 101a, and is rotatably supported by the support portion 101b. The connecting shaft 104a is formed with a hook-like portion 104d at the other end to prevent the connecting shaft 104a from coming out of the through hole 101e. The connecting shaft gear 104 b is non-rotatably mounted on the connecting shaft 104 a and meshes with the second idle gear 123 b of the driving force transmission mechanism 103.

Here, the first and second idle gears 113b and 123b are two-stage gears having different gear diameters. The gear diameter of the connecting shaft gear 104b is larger than the smaller gear diameter of the second idle gear 123b. The first and second idle gears 113b and 123b and the connecting shaft gear 104b mesh with each other, whereby the rotation is reduced.
The connecting portion 104c of the connecting member 104 is connected to a drive unit such as a toner supply device. Here, the connecting portion 104c of the connecting member 104 is connected to a toner transport member 105 that is rotatably mounted on the toner storage container of the toner supply device and transports the toner stored in the toner storage container. The toner conveying member 105 has a coupled portion 105a, and the coupled portion 105a is formed in a rectangular plate shape. The coupled portion 105a can be fitted into the groove portion 204 of the coupling portion 104c. For example, when the connecting portion 104c is connected to the connected portion 105a of the toner conveying member 105, if the surface 204c of the wall portion 204a of the connecting portion 104c comes into contact with the distal end portion of the connected portion 105a, the connecting shaft 104a rotates. Thus, the connected portion 105a is fitted into the groove portion 204 of the connecting portion 104c.

  In such a driving device, first, the rotational driving force is transmitted from the driving gear 102b of the driving motor 102 to the first idle gear 113b. Then, the rotational driving force is transmitted from the first idle gear 113b to the second idle gear 123b. Next, a rotational driving force is transmitted from the second idle gear 123b to the connecting shaft gear 104b, and the connecting shaft 104a is rotated by this rotational driving force. Then, a rotational driving force is transmitted from the connecting portion 104c of the connecting shaft 104a to the driving portion, and the driving portion is driven by this rotational driving force. In this way, the rotation is gradually decelerated by the first and second idle gears 113b and 123b and the connecting shaft gear 104b, and the rotational driving force from the drive motor 102 is transmitted to the drive unit.

Although different from the above configuration, JP-A-8-30061 is cited as a patent document having a configuration in which the rotational driving force from the drive motor is transmitted to the drive unit via the first and second idle gears. Can do.
JP-A-8-30061

  In the conventional image forming apparatus drive device, the first idle gear portion 113 and the second idle gear portion 113 are connected between the drive motor 102 and the connecting member 104 in order to reduce and transmit the rotation from the drive motor 102 to the drive portion. An idle gear portion 123 is disposed in the case main body 101a. In order to arrange the first and second idle gear portions 113 and 123 in the case main body 101a of the drive device case, the first and second idle gear portions 113 and 123 are arranged in the case main body 101a. It is necessary to ensure a space for the case main body 101a. In order to attach the first and second idle gear portions 113 and 123 to the case main body 101a, it is necessary to form the first and second gear bearings 101c and 101d on the case main body 101a. Thus, a space for arranging the first and second idle gear portions 113 and 123 in the case main body 101a is secured in the case main body 101a, and the first and second gear bearings 101c and 101d are provided in the case main body 101a. There is a problem that the drive device becomes large due to the formation.

Further, in the conventional driving device of the image forming apparatus, the support portion 101b of the driving device case 101 and the driving motor 102 are mounted on the case main body 101a by screw members such as bolts and screws. That is, when assembling the drive device, an assembly operator needs to work to screw the screw member into the case main body 101a in a state where the support portion 101b or the drive motor 102 and the case main body 101a are positioned with respect to each other. For this reason, there is a problem that it is difficult for an assembling worker to assemble the support portion 101b and the drive motor 102 to the case main body 101a.

  Further, in the conventional driving device of the image forming apparatus, the retaining portion 104d is provided to prevent the connecting shaft 104a from coming out of the through hole 101e of the support portion 101b. A hook 104 is formed on the other end of the connecting shaft 104 a of the member 104. Although it is considered that the connecting shaft 104a does not come out of the through hole 101e of the support portion 101b by engaging the retaining portion 104d formed in a bowl shape in the vicinity of the through hole 101e, When vibration or impact is transmitted to the connecting shaft 104a during conveyance or driving of the driving device, the retaining portion 104d engaged in the vicinity of the through hole 101e is disengaged depending on the situation, and the connecting shaft 104a is disengaged. Has a problem that it comes out of the through hole 101e.

  Further, in the conventional image forming apparatus driving device, when the connecting portion 104c is connected to the connected portion 105a, the surface 204c of the wall portion 204a of the connecting portion 104c comes into contact with the distal end portion of the connected portion 105a. When the shaft 104a rotates, the coupled portion 105a is fitted and engaged with the groove portion 204 of the coupling portion 104c. For this reason, when the to-be-connected part 105a meshes with the groove part 204 of the coupling part 104c, there is a problem that a meshing sound, that is, a collision sound is generated due to a step between the surface 204c and the bottom part 204b.

An object of the present invention is to make it difficult for a connecting member of a drive device to come out of a case for a drive device.
Another object of the present invention is to make it difficult to generate a collision sound that may occur when the connecting member of the drive device and the drive unit are connected.

The invention according to claim 1 is a drive device for an image forming apparatus for driving a drive unit disposed inside the image forming apparatus main body.
A case for a driving device mounted on the driving unit and having a support unit integrally formed;
A drive means mounted on the drive device case and having a rotation shaft that outputs a rotation drive force and a drive gear that is non-rotatably mounted on the rotation shaft;
A connecting shaft having a connecting portion rotatably attached to the support portion of the case for the driving device and connectable to the driving portion; a first gear rotatably attached to the connecting shaft and meshing with the driving gear; A coupling member having a second gear that is non-rotatably mounted on the coupling shaft coaxially with the first gear;
A driving force transmission mechanism for transmitting a rotational driving force from the first gear to the second gear;
In the drive device of the image forming apparatus comprising:
The support portion of the case for the driving device has a through hole for inserting the connecting shaft and a protrusion formed integrally with the support portion in the vicinity of the through hole.
The connecting shaft of the connecting member has a retaining portion formed on the connecting shaft for preventing the connecting shaft from coming out of the through hole, and the retaining portion is fitted to the protrusion. A possible recess is formed.

The invention according to claim 2 is the invention according to claim 1, wherein the connecting portion of the connecting shaft has a groove formed in a concave shape.
The groove portion has a pair of opposed wall portions and a bottom portion provided between the pair of wall portions,
The wall portion includes a curved surface formed in a spiral shape in the rotation direction of the connecting shaft so that a step difference between the wall portion and the bottom portion increases as the distance from the bottom portion increases.
The drive unit includes a coupled portion that can be fitted into the groove along the curved surface when the coupling shaft rotates .

According to a third aspect of the present invention, in the second aspect of the present invention, the curved surface is formed such that a step difference between the curved surface and the bottom increases as the distance from the rotation axis of the connecting shaft increases. .

According to a fourth aspect of the present invention, in the first or second aspect of the present invention, the curved surface is smoothly connected to the bottom portion.

According to the present invention, since the concave portion of the retaining portion formed on the coupling shaft of the coupling member is fitted to the protrusion formed on the support portion of the drive device case, the image forming apparatus can be transported or driven. Even if vibration or impact is transmitted to the connecting shaft during driving of the device, the connecting member of the driving device can be regulated so as not to come out of the case for the driving device. Further, since the wall portion of the groove portion of the connecting portion includes a spiral curved surface, even when the connecting member is connected to the driving portion at the connecting portion, the wall portion of the groove portion may contact the connected portion of the driving portion. When the connecting shaft rotates, the connected portion can gradually move to the bottom portion of the groove portion along the curved surface, and it is possible to make it difficult to generate a collision sound that may occur when the connecting member and the driving portion are connected.

  FIG. 6 is a schematic sectional view of an image forming apparatus, that is, a tandem type color printer according to an embodiment of the present invention. The color printer includes an image forming unit 2 (2M, 2Y, 2C, 2B) for each color for forming a color image, a toner supply device 3 (3M, 3Y, 3C, 3B) for each color, and a transport for transporting paper. The paper is fed to the belt 4, the first to fourth transfer rollers 5M, 5Y, 5C, and 5B for transferring the toner images of the respective colors onto the conveyed paper, and the image forming units 2M, 2Y, 2C, and 2B. It has a paper feed mechanism 6, a fixing unit 7 for fixing the toner image transferred onto the paper, and a discharge unit 8. The image forming unit 2, the toner supply device 3, the conveying belt 4, the transfer rollers 5M, 5Y, 5C, and 5B, the paper feeding mechanism 6, and the fixing unit 7 are disposed inside the printer main body 1 of the color printer. Has been. The discharge unit 8 is provided on the upper part of the printer main body 1 of the color printer.

  The image forming units 2M, 2Y, 2C, and 2B form magenta, yellow, cyan, and black toner images, respectively, and are sequentially arranged in the horizontal direction along the conveyance belt 4 from the upstream side in the conveyance direction of the paper. Has been placed. Each of these image forming units 2M, 2Y, 2C, 2B has a photosensitive drum 10 having a photosensitive layer made of amorphous silicon or the like as an image carrier, and a charger 11 is provided around each photosensitive drum 10. The exposure device 12, the developing device 13, and the cleaning device 14 are arranged in this order.

  The conveying belt 4 is circulated and driven between a driving roller 20 and a driven roller 21. The transport belt 4 sucks and transports the paper transported from the paper feed mechanism 6 through the paper feed transport path 22 in a substantially horizontal direction. The first to fourth transfer rollers 5M, 5Y, 5C, and 5B are disposed so as to face the photosensitive drums 10 of the image forming units 2M, 2Y, 2C, and 2B via the transport belt 4. Each of the first to fourth transfer rollers 5M, 5Y, 5C, and 5B is movable between an upper transfer position and a lower release position by a solenoid 23. Here, when the first to fourth transfer rollers 5M, 5Y, 5C, and 5B are moved upward and arranged at the transfer position, the sheet on the conveyance belt 4 comes into contact with the photosensitive drum 10. On the other hand, when the first to fourth transfer rollers 5M, 5Y, 5C, and 5B are moved downward and disposed at the release position, the sheet on the conveyor belt 4 and the photosensitive drum 10 are separated from each other.

  The paper feed conveyance path 22 is composed of a guide member serving as a conveyance guide and a plurality of roller pairs. On the most downstream side of the paper feed conveyance path 22, toner image formation and paper conveyance are performed. A registration roller pair 25 for synchronization is provided. A suction roller 26 is provided between the registration roller pair 25 and the first transfer roller 5M. In this example, the suction roller 26 is disposed above the driven roller 21 on which the conveyance belt 4 is hung, so as to face the driven roller 21. At this position, the suction roller 26 applies a bias voltage for suction to the leading end portion or the entire surface of the paper so that the paper is attracted to the transport belt 4.

  The fixing unit 7 includes a heating roller having a heater therein and a pressure roller pressed against the heating roller. A paper discharge conveyance path 27 is provided between the fixing unit 7 and the discharge unit 8. As with the paper feed transport path 22, the paper discharge transport path 27 includes a guide member and a plurality of roller pairs. The discharge unit 8 is formed on the upper surface of the apparatus, and the sheet that has passed through the fixing unit 7 is conveyed upward via the sheet discharge conveyance path 27 and discharged to the upper surface of the apparatus.

  The toner supply device 3 (an example of a drive unit) is for supplying toner to the developing device 13, and is disposed on the developing device 13. The toner supply device 3 supplies a toner storage container (not shown) for storing toner, a plurality of toner stirring members (not shown) for stirring the toner in the toner storage container, and the stirred toner to the toner supply It has a toner conveying member 105 (see FIG. 5) for conveying it to the mouth. A connecting portion 53e of a connecting member 53, which will be described later, is connected to such a toner supply device 3. Here, the connecting portion 53e of the connecting member 53 is connected to the toner conveying member 105 of the toner container. The toner conveying member 105 has a coupled portion 105a, and the coupled portion 105a is formed in a rectangular column shape. The toner conveying member 105 is rotationally driven by the driving device 50, and the toner agitating member rotates in conjunction with the rotation of the toner conveying member 105.

As shown in FIGS. 7 to 10, the drive device 50 includes a drive device case 51, drive means 52, a connecting member 53, and a drive force transmission mechanism 54.
The drive device case 51 is attached to the toner supply device 3 by a screw member such as a bolt or a screw. The drive device case 51 is made of synthetic resin. As shown in FIGS. 7 to 9, the drive device case 51 includes a case body 60, a first support portion (an example of a support portion) 61, a second support portion 62, and a third support portion 63. is doing. The first to third support portions 61, 62, 63 are integrally formed with the case body 60.

  The first support portion 61 is a portion provided to attach a connecting member 53 described later to the drive device case 51. The 1st support part 61 is formed in plate shape so that it may mutually oppose. The first support portion 61 is formed with a through hole 61a capable of rotatably supporting a substantially central portion and the other end portion of a connecting shaft 53a of the connecting member 53 described later. The first support portion 61 that supports the other end portion of the connecting shaft 53a of the connecting member 53 is formed with a cylindrical protruding portion 61b that protrudes outward from the outer peripheral portion of the through hole 61a. The protrusion 61b has the same inner diameter as that of the through hole 61a. An annular protrusion 61c is formed at the tip of the protrusion 61b.

The second support portion 62 is a portion provided to attach a driving means 52 described later, for example, a cylindrical drive motor 52 to the drive device case 51. The second support portion 62 is formed with slits 62a into which engagement portions 52d formed on both end surfaces in the rotation axis direction of the drive motor 52 described later can be fitted.
The third support portion 63 is a portion provided for mounting a connecting gear portion 74 of the driving force transmission mechanism 54 described later to the drive device case 51. The third support portion 63 is provided with slits 63a into which both end portions of a rotation shaft of a connection gear portion 74 described later can be fitted.

  The drive means 52 is, for example, a drive motor 52 as shown in FIGS. 7, 9, and 10, and the drive motor 52 is attached to the drive device case 51. Here, the drive motor 52 is fitted and attached to the drive device case 51. The drive motor 52 has a cylindrical motor body 52a, a rotating shaft 52b, and a drive gear 52c. The motor main body 52a is a driving source and generates a rotational driving force. The motor main body 52a is formed with engaging portions 52d on both end surfaces in the direction of the rotation shaft 52b. The motor main body 52 a is supported by the second support portion 62 by fitting these engaging portions 52 d into slits 62 a formed in the second support portion 62 of the drive device case 51. The rotating shaft 52b is rotatably provided on the motor main body 52a, and outputs the rotational driving force generated by the motor main body 52a. The drive gear 52c is a worm gear and is non-rotatably attached to the rotating shaft 52b.

  As shown in FIGS. 10 and 11, the connecting member 53 has a connecting shaft 53a, a first gear 53b, a second gear 53c, and an urging means 53d. The connecting shaft 53 a is rotatably mounted on the first support portion 61 of the drive device case 51. Specifically, the connecting shaft 53a is inserted into the through hole 61a and the protruding portion 61b of the first support portion 61 formed in a plate shape so as to face each other, and is rotatable in the through hole 61a and the protruding portion 61b. (See FIGS. 7 and 8). A connecting portion 53e is formed at one end of the connecting shaft 53a, and this connecting portion 53e can be connected to a toner conveying member 105 (see FIG. 5) of the toner supply device 3.

  The connection part 53e has the groove part 153 formed in the concave shape. The connecting portion 53e is formed in a cylindrical shape, and the groove portion 153 is provided on the inner peripheral portion of the connecting portion 53e. The groove portion 153 has a pair of opposed wall portions 153a and a bottom portion 153b provided between the pair of wall portions 153a. The wall portion 153a includes a curved surface 153c. The curved surface 153c is formed in a spiral shape in the rotation direction of the connecting shaft 53a (the arrow direction in FIG. 11) so that a step between the curved surface 153c and the bottom portion 153b increases as the distance from the bottom portion 153b increases. That is, the curved surface 153c is formed in a spiral shape in the rotational direction of the connecting shaft 53a so that the distance between one point on the curved surface 153b and the surface of the bottom 153b increases as the distance from the bottom 153b increases. Further, the curved surface 153c is formed such that a step between the bottom portion 153b, that is, a distance from the bottom portion 153b increases as the distance from the rotation axis of the connecting shaft 53a increases. That is, the curved surface 153c is formed in a spiral shape in the rotational direction of the connecting shaft 53a so that the distance between one point on the curved surface 153b and the surface of the bottom portion 153b increases as the distance from the rotating shaft of the connecting shaft 53a increases. . Furthermore, the curved surface 153c is smoothly connected to the bottom 153b. The groove portion 153 of the connecting portion 53e can be fitted to the connected portion 105a of the toner conveying member 105. Specifically, the coupled portion 105 a can be fitted into the groove portion 153 along the curved surface 153 c when the coupling member 53 rotates.

  A retaining portion 73 is formed on the connecting shaft 53a. Specifically, the retaining portion 73 is formed integrally with the other end portion of the connecting shaft 53a. The retaining portion 73 is for preventing the connecting shaft 53a from coming out of the through hole 61a. The retaining portion 73 includes a pair of rod-shaped portions 73a extending from the coupling shaft 53a outward in the axial direction of the coupling shaft 53a, and a hook-shaped portion 73b integrally formed at the distal ends of the pair of rod-shaped portions 73a. Yes. A recess 73 c that can be fitted to the protrusion 61 c formed on the protrusion 61 b of the first support 61 is formed in the flange 73 b.

  The first and second gears 53b and 53c are disposed between a first support portion 61 that supports a substantially central portion of the connection shaft 53a and a first support portion 61 that supports the other end portion of the connection shaft 53a. (See FIG. 7). The first gear 53b is a reduction gear for reducing the rotation. The first gear 53b is a two-stage gear having a different gear diameter. The first gear 53 b is rotatably attached to the connecting shaft 53 a and meshes with the drive gear 52 c of the drive motor 52. Specifically, the gear having the larger gear diameter in the first gear 53b meshes with the drive gear 52c. The second gear 53c is coaxially connected to the first gear 53b and is non-rotatably attached to the connecting shaft 53a. The biasing means 53d is, for example, a coil spring 53d, and the coil spring 53d is disposed on the outer periphery of the connecting shaft 53a between the connecting portion 53e and the first support portion 61 that supports the substantially central portion of the connecting shaft 53a. (See FIG. 8).

  As shown in FIGS. 9 and 10, the driving force transmission mechanism 54 is for transmitting a rotational driving force from the first gear 53b to the second gear 53c. The driving force transmission mechanism 54 includes a connecting gear portion 74. The connecting gear portion 74 is fitted and attached to the drive device case 51. The connection gear part 74 has a rotating shaft 74a and a connection gear 74b. The rotating shaft 74 a of the connecting gear portion 74 is supported by fitting both end portions into a slit 63 a provided in the third support portion 63 of the drive device case 51 so as not to rotate. The connecting gear 74b is rotatably mounted on the rotating shaft 74a. The connection gear 74b is a reduction gear for reducing the rotation. The connecting gear 74b is a two-stage gear with different gear diameters. The connecting gear 74b meshes with the first gear 53b and the second gear 53c, and transmits the rotational driving force from the first gear 53b to the second gear 53c. Specifically, the gear having the larger gear diameter in the coupling gear 74b is engaged with the gear having the smaller gear diameter in the first gear 53b. Further, the smaller gear diameter of the connecting gear 74b meshes with the second gear 53c. Here, the smaller gear diameter of the connecting gear 74b is smaller than the gear diameter of the second gear 53c.

  A method for assembling the drive device 50 as described above will be described below. First, the connecting shaft 53a is inserted into the through hole 61a of the first support portion 61 of the drive device case 51 in a state where one end of the coil spring 53d is in contact with the connecting portion 53e side of the connecting shaft 53a. At this time, the first and second gears 53b and 53c are mounted on the connecting shaft 53a between the first support portions 61 facing each other. Then, when the other end portion of the connecting shaft 53a is inserted into the protruding portion 61b of the first support portion 61, the hooked portion 73b of the retaining portion 73 of the connecting shaft 53a is engaged with the distal end portion of the protruding portion 61b. . At this time, the recessed part 73c formed in the hook-shaped part 73b is fitted to the protruding part 61c formed in the protruding part 61b. Next, the both ends of the rotating shaft 74 a of the connection gear portion 74 are fitted into the slits 63 a provided in the third support portion 63 of the drive device case 51, so that the connection gear portion 74 is connected to the drive device case 51. It is attached to the second support part 62. At this time, the gear having the larger gear diameter in the connecting gear 74b is engaged with the gear having the smaller gear diameter in the first gear 53b. At the same time, the gear having the smaller gear diameter in the connecting gear 74b is engaged with the second gear 53c. Finally, the drive motor 52 is supported by the second support portion 62 by fitting the engagement portion 52 d of the drive motor 52 into the slit 62 a formed in the second support portion 62 of the drive device case 51. At this time, the drive gear 52c of the drive motor 52 is meshed with the gear having the larger gear diameter in the first gear 53b.

  Next, a method for connecting the driving device 50 and the toner supply device 3 as described above will be described below. The driving device 50 and the toner supply device 3 are connected by connecting the connecting member 53 of the driving device 50 to the toner conveying member 105 of the toner supply device 3. Specifically, the connecting member 53 is connected to the toner conveying member 105 by fitting the groove 153 of the connecting portion 53 e of the connecting member 53 into the connected portion 105 a of the toner conveying member 105. More specifically, when the connecting member 53 is brought close to the toner conveying member 105 on the same axis, the bottom portion 153b of the groove 153 of the connecting member 53 and the connected portion 105a of the toner conveying member 105 are in the longitudinal direction of each other. When the arrangement is such that the (longitudinal direction perpendicular to the axial direction) is parallel, the groove 153 is directly fitted into the coupled portion 105a. On the other hand, when the bottom portion 153b of the groove portion 153 of the connecting member 53 and the connected portion 105a of the toner conveying member 105 are arranged so that their longitudinal directions (longitudinal directions orthogonal to the axial direction) are not parallel to each other. First, both end portions of the coupled portion 105a come into contact with the curved surface 153c of the groove portion 153. Next, as the connecting member 53 rotates, both end portions of the connected portion 105a follow the curved surface 153c, and the axially leading end portion of the connected portion 105a approaches toward the bottom portion 153b of the groove portion 153. That is, the interval between the axial front end portion of the coupled portion 105a and the bottom portion 153b of the groove portion 153 gradually decreases. And when the axial direction front-end | tip part of the to-be-connected part 105a contact | abuts to the bottom part 153b of the groove part 153, the groove part 153 is fitted by the to-be-connected part 105a. The axial direction used here is the axial direction of the connecting shaft 53a.

  Finally, the operation of the driving device 50 will be described below. When the drive gear 52c is rotated by the drive motor 52, the first gear 53b rotates around the connection shaft 53a, and the connection gear 74b rotates around the rotation shaft 74a in conjunction with the rotation of the first gear 53b. The second gear 53c rotates together with the connecting shaft 53a in conjunction with the rotation of 74b. Then, the rotational driving force is transmitted to the toner conveying member 105 of the toner supply device 3 from the connecting portion 53e formed at one end of the connecting shaft 53a. In the drive device 50 that operates in this way, when the coupling gear 74b rotates in conjunction with the rotation of the first gear 53b, the gear having the smaller gear diameter in the first gear 53b and the gear diameter in the coupling gear 74b are large. Since the other gear is engaged, the rotation of the connecting gear 74b is decelerated. When the second gear 53c rotates in conjunction with the rotation of the connecting gear 74b, the gear having the smaller gear diameter in the connecting gear 74b and the second gear 53c having a larger gear diameter are engaged with each other. The rotation of the second gear 53c is decelerated. Thus, the rotation from the drive motor 52 is decelerated when transmitted from the first gear 53b to the connecting gear 74b and when transmitted from the connecting gear 74b to the second gear 53c, and the rotation of the connecting shaft 53a is reduced. The rotation is transmitted from the connecting portion 53e to the toner conveying member 105 while being decelerated.

  In this embodiment, since the first and second gears 53b and 53c are mounted on the connecting shaft 53a of the connecting member 53, a space for arranging the first gear 53b in the drive device case 51 is provided. In the drive device case 51, and it is not necessary to form a bearing for mounting the first gear 53b in the drive device case 51 in the drive device case 51, so that the drive device 50 can be reduced in size. Can do. In addition, since the support portion of the drive device case 51 is integrally formed with the drive device case 51, when the assembly operator assembles the drive device 50, the assembly operator attaches the support portion to the drive device case 51. The work of positioning and the work of screwing the screw member for mounting the support portion on the drive device case 51 into the drive device case 51 are unnecessary, and the assembly workability of the drive device 50 can be improved. Further, since the recess 73c of the retaining portion 73 formed on the connecting shaft 53a of the connecting member 53 is fitted to the projection 61c formed on the support portion of the drive device case 51, the image forming apparatus is transported. Even when vibration or impact is transmitted to the connecting shaft 53 a during driving of the driving device 50, the connecting member 53 of the driving device 50 can be regulated so as not to come out of the driving device case 51. Further, since the wall portion 153a of the groove portion 153 of the connecting portion 53e includes a spiral curved surface 153c, when the connecting member 53 is connected to the toner conveying member 105 at the connecting portion 53e, the wall portion 153a of the groove portion 153 is conveyed with toner. Even if it contacts the connected portion 105a of the member 105, the connected portion 105a can gradually move to the bottom portion 153b of the groove portion 153 along the curved surface 153c when the connecting shaft 53a rotates. It is possible to make it difficult to generate a collision sound that may occur at the time of connection with the conveying member 105.

[Other Embodiments]
(A) In the above embodiment, an example in which the image forming apparatus is a color printer has been described. However, the present invention can also be applied to an image forming apparatus such as a copying machine, a printer, or a facsimile.
(B) In the above-described embodiment, an example in which the driving force transmission mechanism 54 includes the coupling gear portion 74 having the rotation shaft 74a and the coupling gear 74b has been described. However, the configuration of the driving force transmission mechanism 54 is described in the above embodiment. The configuration is not limited, and any configuration may be used as long as the rotational driving force can be transmitted from the first gear 53b to the second gear 53c. For example, the driving force transmission mechanism may be composed of a third gear and a connecting gear portion 74. In this case, at least one third gear is disposed coaxially with the first and second gears 53c between the first gear 53b and the second gear 53c, and is rotatably mounted on the connecting shaft 53a. The connection gear part 74 has a rotating shaft and a plurality of connection gears 74b. The rotation shaft is attached to the drive device case 51 so as not to rotate. The plurality of connection gears 74b are rotatably mounted on the rotation shaft. When the driving force transmission mechanism is configured as described above, the plurality of connecting gears 74b can transmit the rotational driving force from the first gear 53b to the second gear 53c via the third gear. Moreover, the same effect as the effect shown in said embodiment can be acquired.

  (C) In the above-described embodiment, an example in which the annular protrusion 61c is formed at the tip of the protrusion 61b has been described. However, the formation position of the protrusion 61c is not limited to the above-described embodiment, and the retainer Any method may be used as long as the concave portion 73c of the portion 73 can be fitted to the protruding portion 61c. For example, the first support portion 61 that supports the other end portion of the connecting shaft 53 a of the connecting member 53 is formed on the side of the retaining portion 73 of the connecting shaft 53 a of the connecting member 53. Then, an annular protrusion 61 c that surrounds the through hole 61 a is formed on the plate-like portion of the first support portion 61. In this way, the recess 73c of the retaining portion 73 is fitted to the protrusion 61c without forming the protrusion 61b on the first support 61 that supports the other end of the connecting shaft 53a of the connecting member 53. be able to.

The perspective view which looked at the conventional drive device from the lower side. The figure which shows the meshing state of the drive means of a conventional drive device, a connection member, and a drive force transmission mechanism. The figure which shows the connection member with which the support part of the conventional drive device was mounted | worn. The expansion perspective view of the connection part of the connection member of the conventional drive device. The expansion perspective view of the drive part which can connect the connecting part of the connecting member of the conventional drive device. 1 is a schematic cross-sectional configuration diagram of a color printer in which this embodiment is adopted. The perspective view of the drive device seen from the retaining part upper side of a connection member. The perspective view of the drive device seen from the connection part side of the connection member. The perspective view of the drive device seen from the retaining part lower part of a connection member. The figure which shows the meshing state of a drive means, a connection member, and a driving force transmission mechanism. The expansion perspective view of the connection part of a connection member.

Explanation of symbols

1 Printer body (image forming device body)
3 Toner supply device (drive unit)
50 drive device 51 drive device case 52 drive motor (drive means)
52a Motor body 52b Rotating shaft of driving motor (Rotating shaft of driving means)
52c driving gear 53 connecting member 53a connecting shaft 53b first gear 53c second gear 53e connecting portion 54 driving force transmission mechanism 61 first support portion (support portion)
61a Through-hole 61c Protruding part 73 Retaining part 73a Bar-like part 73b Hook-like part 73c Recessed part 74 Connecting gear part 74a Rotating shaft of connecting gear part 74b Connecting gear 105 Toner conveying member 105a Connected part 153 Groove part 153a Wall part 153c Curved part 153c

Claims (4)

A drive device for an image forming apparatus for driving a drive unit disposed inside an image forming apparatus main body,
A case for a driving device mounted on the driving unit and having a support unit integrally formed;
A drive means mounted on the drive device case and having a rotation shaft that outputs a rotation drive force and a drive gear that is non-rotatably mounted on the rotation shaft;
A connecting shaft having a connecting portion rotatably attached to the support portion of the case for the driving device and connectable to the driving portion; a first gear rotatably attached to the connecting shaft and meshing with the driving gear; A coupling member having a second gear that is non-rotatably mounted on the coupling shaft coaxially with the first gear;
A driving force transmission mechanism for transmitting a rotational driving force from the first gear to the second gear;
In the drive device of the image forming apparatus comprising :
The support portion of the case for the driving device has a through hole for inserting the connecting shaft and a protrusion formed integrally with the support portion in the vicinity of the through hole.
The connecting shaft of the connecting member has a retaining portion formed on the connecting shaft for preventing the connecting shaft from coming out of the through hole, and the retaining portion is fitted to the protrusion. A drive device for an image forming apparatus, wherein a possible recess is formed. The connecting portion of the connecting shaft has a groove formed in a concave shape,
The groove portion has a pair of opposed wall portions and a bottom portion provided between the pair of wall portions,
The wall portion includes a curved surface formed in a spiral shape in the rotation direction of the connecting shaft so that a step difference between the wall portion and the bottom portion increases as the distance from the bottom portion increases.
The driving unit, the driving device of an image forming apparatus according to claim 1, characterized in that it has a the connected portion which can be fitted into the groove along the curved surface upon rotation of the connecting shaft. 3. The drive device for an image forming apparatus according to claim 2 , wherein the curved surface is formed such that a step difference between the curved surface and the bottom increases as the distance from the rotation axis of the connecting shaft increases. The curved surface, the driving device of an image forming apparatus of claim 2, wherein that it is smoothly connected to the bottom portion.

Images