JP2007139084A - Coupling device and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coupling device wherein a second coupling and a first coupling can be connected to each other even when misalignment occurs and the axial center of the first coupling and the axial center of the second coupling can be aligned to each other when connecting the first coupling and the second coupling to each other, and to provide an image forming device. <P>SOLUTION: A plurality of driving pawls 52b which are integrally formed on a driving side base 52a of a driving side coupling 52 each have a spherical tip portion with a point-like tip, which is thus prevented from crossing a tip portion of a driven pawl 51b arranged on the inner peripheral face of a cylindrical driven side base 51a of a driven side coupling 51 when misalignment occurs in connection. The size and the tolerance of each of an outer diameter ψE1 of the driving pawl 52b and an inner diameter ψD1 of the driven side base 51a are set such that the driven side coupling 51 and the driving side coupling 52 are fitted to each other. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a coupling device having a first coupling and a second coupling that is detachably connected in the axial direction of the first coupling, and an image forming apparatus including the coupling device. .

  Conventionally, a coupling device is used in an image forming apparatus including a copying machine, a printer, a facsimile, and the like, and other various machines and devices (for example, see Patent Document 1). FIG. 25 is a plan view showing an example of a conventional coupling device. A coupling device 500A shown in FIG. 25 includes a driving side coupling 502A and a driven side coupling 501A. The drive side coupling 502A has a plurality of drive claws 504A (only one drive claw is shown in the figure) arranged on the front end surface of the drive side base portion 503A and integrally formed with the drive side base portion 503A. ing. The driven side coupling 502A also has a plurality of driven claws 507A that are disposed on the distal end surface of the driven side base 506A and are integrally formed with the driven side base 506A. As shown in FIG. 25, when the drive side coupling 502A and the driven side coupling 501A are connected to each other, the drive claws 504A and the driven claws 507A are alternately positioned, and the drive claws 504A and the driven claws 507A are located. Are engaged with each other. The drive side coupling 502A is connected to the drive shaft 508A, and the drive side coupling 502A rotates when the drive shaft 508A is rotationally driven by a drive source (not shown). As a result, the driving claw 504A and the driven claw 507A come into pressure contact with each other, the rotation of the driving side coupling 502A is transmitted to the driven side coupling 501A, and the driven shaft 509A fixed to the driven side coupling 501A rotates. A rotating element (not shown) of the driven unit 510A is driven to rotate.

  The driven side coupling 501A is detachably connected to the driving side coupling 502A in the direction of the axis Z1 of the driving side coupling 502A, and the driven side coupling 501A moves in the direction of arrow A together with the driven unit 510A. By doing so, the driven side coupling 501A can be detached from the driving side coupling 502A. By pushing the driven side coupling 501A together with the driven unit 510A in the arrow B direction, the driven side coupling 501A and the driving side coupling 502A can be connected.

  The drive side coupling 502A is attached to the drive shaft 508A so as to be movable in a predetermined stroke in the axial direction thereof, and is a compression spring between a spring receiver 511A fixed to the drive shaft 508A and the drive side coupling 502A. 512A is arranged.

  When the driven side coupling 501A is pushed in the direction of the arrow B, when the top surface 513A of the driven claw 507A and the top surface 514A of the driving claw 504A come into contact with each other, the driving side coupling 502A becomes the driven side coupling. 501A is pressed. Then, the drive side coupling 502A moves in the arrow B direction with respect to the drive shaft 508A, and the compression spring 512A is compressed and deformed. When the driving side coupling 502A rotates in this state, the driving claw 504A rotates with respect to the driven claw 507A, and the driving side coupling 502A moves in the arrow A direction by the pressurizing action of the compression spring 512A. As a result, each driving claw 504A enters between each driven claw 507A, and each driving claw 504A and each driven claw 507A are alternately positioned in the circumferential direction of the coupling device 500A. In this way, each driving claw 504A and each driven claw 507A mesh with each other, and the rotation of the driving side coupling 502A can be transmitted to the driven side coupling 501A.

  As described above, when the driven side coupling 501A and the driving side coupling 502A are connected, even if the top surface 513A of the driven claw 507A and the top surface 514A of the driving claw 504A abut, the driving side coupling 502A By rotation, the driven claw 507A and the driving claw 504A can be engaged with each other.

  However, in the coupling device 500A, even if the top surface 513A of the driven claw 507A and the top surface 514A of the driving claw 504A abut against each other, the driven claw 507A and the driving claw 504A are compressed. The spring 512A is required. For this reason, there was a problem that the number of parts of coupling device 500A will increase. In addition, a large space is required for disposing the compression spring 512A, and there is a problem that the entire coupling device 500A including the spring 512A is enlarged.

In the patent document 2, the present applicant has proposed a coupling device that solves the above problem. FIG. 26 shows a coupling device 500B described in Patent Document 2. FIG. 27 is a perspective view of a coupling device 500B described in Patent Document 2. FIG. As shown in FIG. 26, the coupling device 500B described in Patent Document 2 includes a driving side coupling 502B as a second coupling and a driven side coupling 505B as a first coupling. The drive side coupling 502B has a columnar drive side base 503B fixed to the drive shaft 508B, and a plurality of drive claws 504B arranged on the outer peripheral surface of the drive side coupling. The driven side coupling 505B has a cylindrical driven side base portion 506B fixed to the driven shaft 509B, and a plurality of driven claws 507B arranged on the inner peripheral surface of the driven side base portion 506B. As shown in FIG. 27, an inclined surface 536B is formed at the tip of each drive claw 504B, and the tip 538B of each drive claw 504B is linear extending from the drive side base 504B on the normal line. In addition, an inclined surface 536B that is inclined in the same direction with each drive claw 504B facing is formed at the tip of each driven claw 507B. It has a linear shape that extends.
When the driven claw 507B and the driving claw 504B are in contact with each other when the driven coupling 505B is coupled to the driving side coupling 502B, the inclined surface 535B of the driven claw 507B contacts the inclined surface 536B of the driving claw 504B. When the inclined surface 535B of the driven claw 507B and the inclined surface 536B of the driving claw 504B come into contact with each other, the force for pushing the driven side coupling 505B in the axial direction is dispersed in the rotational direction and the axial direction. Thus, when the driven side coupling 505B is pushed in the axial direction in a state where the inclined surface 535B of the driven claw 507B and the inclined surface 536B of the driving claw 504B are in contact with each other, the inclined surface 535B of the driven claw 507B is inclined. At least one of the driven side coupling 505B and the driving side side coupling 502B rotates while the sliding surface 536B of the driving claw 504B slides on each other. As a result, each driven claw 507B enters between each drive claw 504B, and the drive claw 504B and the driven claw 507B mesh with each other.

  In the coupling device 500B described in Patent Document 2, the driven claw 507B and the driving claw 504B come into contact with each other when the driven side coupling 505B is connected to the driving side coupling 502B without providing the compression spring 512A or the like. However, the driven claw 507B and the driving claw 504B can be engaged with each other. As a result, an increase in the number of parts and an increase in the size of the coupling device can be suppressed.

JP 2002-31153 A JP 2005-76873 A

  FIG. 28 is a diagram showing a state where the driven unit 510B including the driven side coupling 505B of the coupling device 500B of Patent Document 2 is attached to the back plate 516B of the device. As shown in FIG. 28, a hole 517B into which the shaft 511B of the driven unit 510B is inserted is provided in the back side plate 516B. When the driven unit 510B is mounted on the apparatus main body, the driven unit is moved in the axial direction, the shaft 511B is inserted into the hole 517B, the driven unit 510B is positioned, and the driven side coupling 505B and The drive side coupling 502B is connected. When the driven unit 510B is positioned and then the driven side coupling 505B and the driving side coupling 502B are connected, the axis of the driving side coupling 502B and the axis of the driving side coupling 505B are displaced at the time of connection. May end up. This is because the driven unit 510B is preliminarily positioned, so that an axial misalignment occurs due to accumulation of dimensional tolerances such as component accuracy and holes 517B and deflection due to the rigidity of the unit.

  FIG. 29 is a view of the driven side coupling 505B seen from the direction E shown in FIG. 26, and the phantom line of the two-point cutting line in the drawing indicates the driving side coupling 502B. As shown in FIG. 29, when the axial centers of the driving side coupling 502B and the driven side coupling 507B are the same, the linear tip 538B of the driving claw 504B and the linear tip 540B of the driven claw 507B are: It is parallel. As shown in FIG. 29, when the linear tip 538B of the drive claw 504B and the linear tip 540B of the driven claw 507B are parallel to each other, the linear tip 538B of the drive claw 504B is connected to the driven claw 507B. The driven side coupling 505B can be well connected to the driving side coupling 502B without hitting the linear tip 540B. However, as shown in FIG. 30, when the axial centers of the drive side coupling 502B and the driven side coupling 505B are shifted, the linear tip 538B of the drive claw 504B is shown as indicated by X in the figure. And the linear tip 540B of the driven claw 507B cross each other. This is because both the tip of the drive claw and the tip of the driven claw are linear, and if the axial center is shifted, the angle between the tip 538B (line) of the drive claw 504B and the tip 540B (line) of the driven claw 507B is Therefore, the tip 538B of the driving claw 504B and the tip 540B of the driven claw 507B cross each other. In this way, when the driven side coupling 504B is connected to the driving side coupling 502B in a state where the axis of the driving side coupling 502B and the driven side coupling 505B are displaced, the linear tip of the driven claw 507B is obtained. 540B hits the linear tip 538B of the drive claw 504B, and the driven side coupling 505B cannot be moved to the drive side coupling side. As a result, there is a problem that the driven side coupling 505B and the driving side coupling 502B cannot be connected. Further, if the forcible follower side coupling 505B and the driving side coupling 502B are connected with the claws abutted against each other, the tips of the claws or the driven unit 510B may be deformed or damaged. There was a problem.

  In order to solve the above problem, the present applicant has proposed the following coupling device in Japanese Patent Application No. 2005-200143. That is, the coupling device has a hemispherical or conical tip at least one of the driven claw of the driven side coupling and the driving claw of the driving side coupling. As a result, at least one tip of the driven claw of the driven side coupling and the driving claw of the driving side coupling becomes a point, and when connecting the driving side coupling and the driven side coupling, the driving side coupling and the driven side cup Even if the axial center of the ring is displaced, the tip of the driving claw and the tip of the driven claw do not intersect. As a result, when connecting the driving side coupling and the driven side coupling, it is possible to prevent the driving side coupling and the driven side coupling from becoming unable to be connected due to the tip of the driving claw hitting the tip of the driven claw. Can do.

  However, in the coupling device proposed in Japanese Patent Application No. 2005-200143, the driving side coupling and the driven side coupling are connected even when the axis of the driving side coupling and the axis of the driven side coupling are displaced. Will be. If the drive-side coupling and the driven-side coupling are connected with the drive-side coupling and the driven-side coupling being misaligned, the shaft is used to transmit the drive to the driven unit. Rotation unevenness occurs every rotation due to deviation. When the driven unit is a photoconductor, if such rotation unevenness occurs, the driven unit vibrates due to the rotation unevenness and abnormal noise is generated, or when the driven unit is a photoconductor, abnormal images such as banding are displayed. There was a problem that caused it.

  The present invention has been made in view of the above problems, and an object of the present invention is to connect the second coupling and the first coupling even when the axial center is shifted, and to connect the first coupling. A coupling device and an image forming apparatus capable of aligning the axis of the first coupling and the axis of the second coupling at the time of connection between the first coupling and the second coupling.

In order to achieve the above object, a first aspect of the present invention is a cylindrical first base portion attached to an end portion of a first rotating shaft, and a plurality of first claws disposed on an inner peripheral surface of the first base portion. A second coupling having a columnar second base attached to the shaft end of the second rotating shaft and a plurality of second claws disposed on the outer peripheral surface of the second base. The second coupling is detachably connected to the first coupling in the axial direction of the second coupling, and when the first coupling and the second coupling are connected, In the coupling device in which the second base is inserted into the first base so that the first claws and the second claws are alternately positioned and the first claws and the second claws mesh with each other. , The tip of at least one of the first claw and the second claw as a point, the first coupling and the second coupling The first coupling and the second coupling are configured to be fitted so that the axial center of the first coupling and the axial center of the first coupling are aligned when connected to the ring. To do.
The invention of claim 2 is the coupling device of claim 1, wherein when the first coupling and the second coupling are connected, the first coupling is It is characterized by being relatively movable in the direction in which the axes meet.
According to a third aspect of the present invention, there is provided the coupling device according to the first or second aspect, wherein the inner peripheral surface of the first base and the outer peripheral surface of each of the second claws are fitted to each other. And the second coupling are fitted.
According to a fourth aspect of the present invention, in the coupling device of the third aspect, the inner peripheral surface of the first base portion is tapered so that the inner diameter decreases toward the first rotating shaft side. It is.
The invention of claim 5 is characterized in that, in the coupling device of claim 3 or 4, the outer peripheral surface of each of the second claws is tapered so that the outer diameter increases toward the second rotating shaft. It is what.
According to a sixth aspect of the present invention, there is provided the coupling device according to the first or second aspect, wherein the outer peripheral surface of the second base and the inner peripheral surface of the first claws are fitted to each other, whereby the first coupling is performed. And the second coupling are fitted.
The invention of claim 7 is the coupling device of claim 6, wherein the outer peripheral surface of the second base portion is tapered so that the outer diameter increases toward the second rotating shaft. It is.
The invention according to claim 8 is the coupling device according to claim 6 or 7, wherein the inner peripheral surface of each of the first claws is tapered so that the inner diameter decreases toward the first rotating shaft. It is what.
The invention of claim 9 is characterized in that the coupling device according to any one of claims 1 to 8 is provided.

According to invention of Claims 1 thru | or 9, when connecting the 2nd coupling and the 1st coupling by making the tip of at least one of the 1st claw and the 2nd claw into a point, the 1st coupling Even if the axial center of the second coupling is shifted, the tips of both claws do not intersect the tips of the first and second claws unlike the linear coupling device. As a result, when the second coupling and the first coupling are connected, it is possible to prevent the second coupling and the first coupling from being unable to be connected because the tip of the second claw hits the tip of the first claw. can do.
In addition, a cylindrical second base is inserted into the first base so that the first claw and the second claw mesh with each other in the cylindrical first base, and the first coupling and the second coupling are Since the first coupling and the second coupling are fitted so that the axial centers of the first coupling and the second coupling are aligned when connected, the following effects can be obtained. That is, it is possible to suppress rotation unevenness for each rotation due to axial misalignment, and to suppress abnormal noise caused by vibration of the driven unit caused by rotation unevenness.

Hereinafter, an embodiment in which the present invention is applied to an electrophotographic tandem color laser printer (hereinafter simply referred to as a printer) as an image forming apparatus will be described.
[Overall Configuration] FIG. 1 is a schematic configuration diagram of a laser printer according to the first embodiment. This laser printer includes four sets of process units 1Y, M, C, and K for forming images of each color of yellow (Y), magenta (M), cyan (C), and black (K). Needless to say, Y, M, C, and K appended to the numerals of the respective symbols indicate members for yellow, magenta, cyan, and black (the same applies hereinafter). In addition to the process units 1Y, 1M, 1C, and 1K, an optical writing unit 10, a transfer unit 11, a registration roller pair 19, three paper feed cassettes 20, a fixing unit 21, and the like are disposed.

[Optical Writing Unit] The optical writing unit 10 includes four optical writers. Each optical writer includes a light source, a polygon mirror, an f-θ lens, a reflection mirror, and the like, and irradiates a laser beam on the surface of a photoconductor described later based on image data.

[Process Unit] FIG. 2 is an enlarged view showing a schematic configuration of the process unit 1Y for yellow among the process units 1Y, 1M, 1C, and 1K. Since the other process units 1M, 1C, and 1K have the same configuration, their descriptions are omitted. In FIG. 2, the process unit 1Y includes a drum-shaped photoreceptor 2Y, a charger 30Y, a developing device 40Y, a drum cleaning device 48Y, and the like.

  The charger 30Y uniformly charges the drum surface by sliding a charging roller to which an AC voltage is applied against the photoreceptor 2Y. The surface of the photoreceptor 2Y subjected to the charging process is irradiated with the laser beam modulated and deflected by the optical writing unit 10 while being scanned. Then, an electrostatic latent image is formed on the drum surface. The formed electrostatic latent image is developed by the developing device 40Y to become a Y toner image.

  The developing device 40Y has a developing roller 42Y disposed so as to be partially exposed from the opening of the casing. Further, it also includes a first transport screw 43Y, a second transport screw 44Y, a developing doctor 45Y, a toner concentration sensor (hereinafter referred to as T sensor) 46Y, and the like.

  A two-component developer containing a magnetic carrier and negatively chargeable Y toner is accommodated in the casing. The two-component developer is frictionally charged while being agitated and conveyed by the first conveying screw 43Y and the second conveying screw 44Y, and then carried on the surface of the developing roller 42Y. Then, after the layer thickness is regulated by the developing doctor 45Y, the layer is conveyed to a developing region facing the photoreceptor 2Y, where Y toner is attached to the electrostatic latent image on the photoreceptor 2Y. This adhesion forms a Y toner image on the photoreceptor 2Y. The two-component developer that has consumed Y toner by development is returned to the casing as the developing roller 42Y rotates.

  A partition wall 47Y is provided between the first transport screw 43Y and the second transport screw 44Y. The partition wall 47Y separates the first supply unit that accommodates the developing roller 42Y, the first conveyance screw 43Y, and the like and the second supply unit that accommodates the second conveyance screw 44Y in the casing. The first conveying screw 43Y is rotationally driven by a driving unit (not shown), and supplies the two-component developer in the first supply unit to the developing roller 42Y while conveying the two-component developer from the front side to the back side in the drawing. The two-component developer conveyed to the vicinity of the end of the first supply unit by the first conveyance screw 43Y enters the second supply unit through an opening (not shown) provided in the partition wall 47Y. In the second supply section, the second transport screw 44Y is driven to rotate by a driving means (not shown), and transports the two-component developer sent from the first supply section in the direction opposite to that of the first transport screw 43Y. . The two-component developer transported to the vicinity of the end of the second supply unit by the second transport screw 44Y returns to the first supply unit through the other opening (not shown) provided in the partition wall 47Y. .

  The T sensor 46Y including a magnetic permeability sensor is provided on the bottom wall near the center of the second supply unit, and outputs a voltage having a value corresponding to the magnetic permeability of the two-component developer passing therethrough. Since the magnetic permeability of the two-component developer has a certain degree of correlation with the toner density, the T sensor 66Y outputs a voltage having a value corresponding to the Y toner density. This output voltage value is sent to a control unit (not shown). This control unit includes a RAM, in which Y Vtref, which is a target value of the output voltage from the T sensor 46Y, is stored. In addition, data of M Vtref, C Vtref, and K Vtref, which are target values of output voltage from a T sensor (not shown) mounted in another developing device, is also stored. The Y Vtref is used for driving control of a Y toner conveying device (not shown). Specifically, the control unit drives and controls a Y toner conveying device (not shown) so that the value of the output voltage from the T sensor 46Y approaches the V Vref for Y to replenish Y toner in the second supply unit 49Y. Let By this replenishment, the Y toner concentration of the two-component developer in the developing device 40Y is maintained within a predetermined range. Similar toner replenishment control is performed for the developing devices of other process units.

  The Y toner image formed on the Y photoconductor 2Y is transferred onto a transfer sheet that is transported to a paper transport belt described later. The surface of the photoreceptor 2Y after the transfer is neutralized by a static eliminator (not shown) after the transfer residual toner is cleaned by the drum cleaning device 48Y. Then, it is uniformly charged by the charger 30Y and prepared for the next image formation. The same applies to other process units. As shown in FIG. 3, each of the process units 1Y, 1M, 1C, and 1K is detachable from the printer body, and is replaced when the service life is reached.

[Transfer Unit] In FIG. 1 described above, the transfer unit 11 includes a paper transport belt 12, a drive roller 13, a stretching roller 14, four transfer bias rollers 17Y, M, C, and K. . The paper conveying belt 12 is endlessly moved counterclockwise in the figure by a driving roller 13 that is rotated by a driving system (not shown) while being tensioned by the driving roller 13 and the stretching rollers 14 and 15. A transfer bias is applied to each of the four transfer bias rollers 17Y, 17M, 17C, and 17K from a power source (not shown). Then, the paper conveying belt 12 is pressed from the back surface thereof toward the photoreceptors 2Y, 2M, 2C, and 2K to form transfer nips. At each transfer nip, a transfer electric field is formed between the photoconductor and the transfer bias roller due to the influence of the transfer bias. The above-mentioned Y toner image formed on the Y photoconductor 2Y is transferred onto the transfer paper P that is transported onto the paper transport belt 12 due to the influence of the transfer electric field and nip pressure. On the Y toner image, the M, C, and K toner images formed on the photoreceptors 2M, 2C, and 2K are sequentially superimposed and transferred. By such superposition transfer, a full-color toner image combined with the white color of the paper is formed on the transfer paper P transported on the paper transport belt 12.

[Paper Feed Cassettes] Below the transfer unit 11, three paper feed cassettes 20 for accommodating a plurality of transfer papers P in a stacked manner are arranged in multiple stages, and each cassette is the top transfer paper. A paper feed roller is pressed against P. When the paper feed roller is driven to rotate at a predetermined timing, the uppermost transfer paper P is fed to the paper transport path.

[Registration Roller Pair] The transfer paper P fed from the paper feed cassette 20 to the paper conveyance path is sandwiched between the rollers of the registration roller pair 19. The registration roller pair 19 sends out the transfer paper P sandwiched between the rollers at a timing at which toner images can be superimposed at each transfer nip. As a result, the toner image is superimposed and transferred onto the transfer paper P at each transfer nip. The transfer paper P on which the full color image is formed is sent to the fixing unit 21.

[Fixing Unit] The fixing unit 21 forms a fixing nip by a heating roller 21a having a heat source such as a halogen lamp inside and a pressure roller 21b pressed against the heating roller 21a. The full color image is fixed on the surface of the transfer paper P while being sandwiched in the fixing nip. The transfer paper P that has passed through the fixing unit 21 is discharged out of the apparatus through a pair of paper discharge rollers (not shown).

  In the present embodiment, as shown in FIG. 4, the fixing unit 21 and the transfer unit 11 can be pulled out from the apparatus main body by a pull-out mechanism in the apparatus main body. The fixing unit 21 or the transfer unit 11 is pulled out from the apparatus main body, and is detached from the apparatus main body.

Next, a characteristic configuration of the laser printer will be described.
FIG. 5 is a cross-sectional view showing a drive connecting portion of the fixing unit 21 as a driven unit. The fixing unit 21 shown in FIG. 5 includes a case 22, a fixing roller 21a disposed inside the case 22, and a pressure roller 21b (not shown). The pressure roller 21b is in pressure contact with the fixing roller 21a. Then, it is rotationally driven in conjunction with the fixing roller 21a. A roller gear 24 is fixed to the shaft 23 of the fixing roller 21, and a coupling gear 25 fixed to a driven shaft 26 rotatably supported on the side surface of the case 22 is engaged with the roller gear 24. A driven side coupling 51, which is a second coupling of the coupling device 50, is fixed concentrically to the tip of the driven shaft 26. Further, one end of the shaft 23 of the fixing roller 21 is rotatably supported by a face plate 28 that is detachably attached to the front side plate 27 of the printer body, and the other end is rotatable in a hole 29 a of the back side plate 29. It is supported.

The drive device 60 as a drive unit is fixed to the back side plate 29 of the image forming apparatus main body, and includes a support plate 61, a drive motor 62 as a drive source, a transmission mechanism 63, and a drive shaft 64. . The drive motor 62 is fixed to the support plate 61. The transmission mechanism 63 includes a transmission gear 63a, a drive pulley 63c, a driven pulley 63d, and a timing belt 63e. The transmission gear 63 a is fixed to a rotary shaft 63 b that is rotatably supported by the support plate 61 and the back plate 29, and meshes with an output gear 62 a that extends from the drive motor 62. A driving pulley 63c is fixed to the rotating shaft 63b, and the timing belt 63e is stretched between the driving pulley 63c and the driven pulley 63d. The driven pulley 63d is fixed to a drive shaft 64 that is rotatably supported by the support plate 61 and the back plate 29. The rotation of the drive motor 62 is transmitted to the drive shaft 64 through the output gear 62a, the transmission gear 63a, the rotating shaft 63b, the driving pulley 63c, the timing belt 63e, and the driven pulley 63d.
A driving side coupling 52 as a first coupling is concentrically fixed to the fixing roller side end of the driving shaft 64.

  As shown in FIG. 5, when the fixing unit 21 is mounted on the printer body, the driving side coupling 52 is inserted into the driven side coupling 51, and the driving side coupling 52, the driven side coupling 51, Are engaged in the rotational direction. Thereby, the rotation of the drive shaft 64 is transmitted to the driven shaft 26 via the coupling device 50, and the fixing roller 21a is rotationally driven. The rotation is transmitted to the pressure roller 21b via a transmission (not shown), and the pressure roller 21b rotates.

  The driven side coupling 51 provided at the tip of the driven shaft 26 of the fixing unit 21 and the driving side coupling 52 provided at the fixing roller side end of the driving shaft 64 of the driving device 60 provided in the apparatus main body. As shown in FIG. 6, the fixing unit 21 is connected when pulled into the apparatus main body.

Next, the coupling apparatus 50 of Example 1 is demonstrated. FIG. 7 is a plan view showing the first embodiment coupling device 50 when the driven side coupling 51 is separated from the driving side coupling 52.
The drive side coupling 52 is arranged on a drive side base 52a, which is a second base portion formed in a columnar shape, and an outer peripheral surface 52f of the drive side base 52a, and a plurality of second portions formed integrally with the drive side base 52a. It has a driving claw 52b which is a claw. As shown in FIG. 8, three driving claws 52b are provided, and are arranged at respective positions obtained by dividing the entire circumference of the driving base 52a into three equal parts. The tip of the driving claw 52b is hemispherical, and the tip 52c of the driving claw is a dot. The tip 52c of one drive claw 52b among the plurality of drive claws 52b of the drive side coupling 52 is arranged closer to the tip 52d of the drive side base 52a than the tips 52c of the other drive claws 52b. ing.

  The driven side coupling 51 includes a driven side base 51a as a first base formed in a cylindrical shape with one open, and a plurality of driven claws as a plurality of first claws arranged on the inner peripheral surface 51f of the driven side base 51a. 51b, and the driven claw 51b is formed integrally with the driven side base 51a. As shown in FIG. 9, the three driven claws 51b are provided, and are arranged at respective positions obtained by dividing the entire circumference of the driven side base 51a into three equal parts. An inclined surface 51c is formed at the tip of the driven claw 51b. The front ends 51d of the plurality of driven claws 51b are linear extending in the axial center. Further, the tips 51d of the plurality of driven claws 51b occupy the same position in the axial direction of the driven side coupling 51, and in the illustrated example, the positions of all the tips 51d are the positions of the tips 51e of the driven side base 51a. It matches.

  Further, the inner diameter φD1 of the inner peripheral surface 51f of the driven side base 51a of the driven side coupling 51 and the outermost diameter φE1 of the outer peripheral surface 52g of the driving claw 52b of the driving side coupling 52 are the same as the driven side coupling 51 and the drive. The dimensions and tolerances are set so that the side coupling fits.

  As shown in FIG. 5, when the driven side coupling 51 and the driving side coupling 52 are connected, one of the cylindrical driving side bases 52a enters the inside of the cylindrical driven side base 51a and is driven. The claw 52b and the driven claw 51b mesh with each other. At this time, the driven side coupling 51 and the driving side coupling 52 are fitted together so that the axis of the driving coupling and the driven coupling are aligned.

  Next, the connection between the driven coupling ring 51 and the drive side coupling 52 will be described. In order to connect the driven side coupling 51 to the driving side coupling 52, the fixing device 21 is slid to the rear side of the device, and the driven side coupling 51 is moved in the direction of the arrow B shown in FIG. 7 with respect to the driving side coupling 52. Move to. At this time, when the inclined surface 51c of the driven claw 51b contacts the front end 52c of the drive claw 52b, first, the front end 52c of the drive claw 52b protruding from the other drive claw toward the front end 52d side of the drive side base 52a; Only the inclined surface 51c of any one driven claw 51b contacts. Thus, since only the tip 52c of one drive claw 52b and the inclined surface 51c of one driven claw 51b are first in contact with each other, the force that pushes the driven side coupling 51 toward the drive shaft side is the protruding drive claw 52b. Concentrate on the tip 52c. Accordingly, at least one of the driving side coupling 52 and the driven side coupling 51 rotates with a small pushing force, and the tip 52c of the driving claw 52b relatively moves on the inclined surface 51c of the driven claw 51b while being driven. Guided between the claws 51b. If the driven side coupling 51 is connected to the driving side coupling 52, if the tips 52c of the plurality of driving claws 52b and the inclined surfaces 51c of the plurality of driven claws 51b are in contact with each other at the same time, a plurality of pushing forces are applied. Dispersed in the drive claw 52b. Therefore, if the driven coupling 51 is not pushed in strongly, at least one of the driving side coupling and the driven side coupling does not rotate, and the tip 52c of the driving claw 52b relatively moves on the inclined surface 51c of the driven claw 51b. I can't. As a result, it becomes difficult to connect the driven side coupling ring 51 and the driving side coupling 52. In the coupling device of this embodiment, when connecting, one driving claw 52b and one driven claw abut, so when connecting, the plurality of driving claws 52b and the plurality of driven claws 51b abut simultaneously. Compared with the coupling device, the driven side coupling ring 51 and the driving side coupling 52 can be easily connected.

  Further, since the tip of the driving claw 52b is hemispherical and the tip 52c is pointed, the tip 52c of the driving claw 52b makes point contact with the inclined surface 51c of the driven claw 51b. As a result, the friction with the inclined surface 51c of the driven claw 51b is reduced, and the driven side coupling 51 can be connected to the driving side coupling 52 with a smaller pushing force.

  Further, when the driving side coupling 52 and the driven side coupling 51 are connected, when the tip 52c of the driving claw 52b contacts the inclined surface 51c of the driven claw 51b, the driving side coupling 51 and the driven side cup Either one of the rings 52 rotates. When the drive side coupling 52 rotates, a rotational load is generated by the inertial force of the timing belt 63e and the gears 62a and 63a. For this reason, in order to rotate the drive side coupling 52, it is necessary to push in the driven side coupling 51 strongly. In addition, when the driven coupling 51 rotates during connection, a rotational load is generated by the inertial force of the fixing roller 21a and the like. Therefore, even when the driven side coupling 51 rotates, the driven side coupling 51 does not rotate unless the driven side coupling 51 is pushed firmly into the apparatus back side during the connection.

  For this reason, as shown in FIG. 5, the electromagnetic clutch 65 is provided between the drive shaft 64 and the driven pulley 63d. When the driving force of the drive motor 62 is transmitted to the fixing roller 21a, the electromagnetic clutch 65 is turned on to connect the drive shaft 64 and the driven pulley 63d. On the other hand, when the driven side coupling 51 and the driving side coupling 52 are connected, the electromagnetic clutch 65 is turned OFF so that the driving shaft 64 can freely rotate with respect to the driven pulley 63d. Thereby, when the driven side coupling 51 and the driving side coupling 52 are connected, the rotational load applied to the driving side coupling 52 becomes only the inertial force of the drive shaft 64, and the rotational load is reduced as compared with the above. Can do. As a result, the driving side coupling 51 can be rotated and the driven side coupling 51 can be connected to the driving side coupling 52 without having to push the driven side coupling 51 into the back side of the apparatus. .

  Further, if a one-way clutch is provided between the drive shaft 64 and the driven pulley 63d instead of the electromagnetic clutch 65, the rotational load on the drive side coupling 52 can be similarly reduced. In this case, the rotation direction of the drive shaft 64 when the drive side coupling 52 and the driven side coupling 51 are connected, and the rotation direction of the drive shaft 64 when the driving force of the drive motor is transmitted to the fixing roller 21a. Keep it different. Specifically, the rotation direction of the drive side coupling 52 when connecting and the rotation direction when transmitting the driving force are made different depending on the inclination direction of the inclined surface 51c of the driven claw 51b. The drive shaft 64 can freely rotate with respect to the driven pulley 63d in the direction in which the drive shaft 64 rotates during connection, and the driven pulley 63d in the direction in which the drive shaft 64 rotates during driving. And the drive shaft 64 are set so that the one-way clutch is rotated. As a result, when the driven side coupling 51 and the driving side coupling 52 are coupled, the rotational load on the driving side coupling 52 is reduced, and the driving side coupling 51 can be driven without being pushed deeply into the back of the apparatus. The side coupling 52 can be rotated to connect the driven side coupling 51 to the driving side coupling 52.

  Further, the shaft center of the driven side coupling 51 and the shaft center of the driving side coupling 52 may be shifted at the time of connection. In the present embodiment, since the dimensional relationship is such that the inner peripheral surface 51f of the driven side base 51a and the outer peripheral surface 52g of the drive claw 52b of the drive side coupling 52 are fitted, this axial center is shifted. When the driven side coupling 51 and the driving side coupling 52 are coupled in this state, the driving claw 52b may come into contact with the distal end portion 51e of the driven side base 51a. However, in the present embodiment, the tip portion of the drive claw 52b is hemispherical. Further, since the coupling between the apparatus main body and the fixed fixing unit is performed by the coupling, the fixing unit is not positioned at the coupling coupling, and the driven coupling has the axis of the driving coupling. It is relatively movable in the direction that fits. Therefore, when the driving claw 52b is in contact with the tip 51e of the driven base 51a and the driven coupling is further pushed into the driving coupling, the tip 51e of the driven base 51a is moved to the tip of the driving claw 52b. The driven coupling relatively moves so that the shaft center of the drive coupling and the shaft center of the driven coupling are guided by the spherical surface portion. As a result, the driving side base 52a is inserted into the driven side base 51a, and the inner peripheral surface 51f of the driven side base 51a and the outer peripheral surface 52g of the driving claw 52b of the driving side coupling 52 are fitted. As a result, the fixing unit 22 is positioned with respect to the apparatus main body.

In this way, the inner peripheral surface 51f of the driven base 51a and the outer peripheral surface 52g of the drive claw 52b of the drive side coupling 52 are fitted so that the axes are aligned with each other at the time of connection. The side coupling 51 is fitted in a state where the axis is aligned. Thereby, the shaft center of the drive coupling and the shaft center of the driven coupling do not shift after the connection. Therefore, the rotational driving force is not transmitted to the fixing roller 21 in a state where the axis of the drive coupling and the axis of the driven coupling are displaced, and the rotation unevenness occurs every rotation of the fixing roller 21. Can be suppressed.
Further, since the driving side coupling and the driven side coupling are fitted together at the time of connection, the fixing unit can only move in the axial direction with respect to the apparatus main body after the connection. Therefore, the fixing unit can be positioned with respect to the apparatus main body by connecting the driving side coupling and the driven side coupling. As a result, there is no need to provide a positioning pin for positioning with the apparatus main body in the fixing unit, the number of parts of the fixing unit can be reduced, and the cost can be reduced.

  The tip 51e of the driven base 51a may be an inclined surface that is inclined from the outside to the inside from the drive shaft 64 side to the driven shaft 23 side. By using the tip 51e as an inclined surface, this inclined surface can also be used as a guide for aligning the axial centers of the drive side coupling and the driven side coupling by the connecting operation. As a result, the driven side coupling is moved in the direction in which the axis is aligned without having to push the driven side coupling strongly into the driving side coupling side, compared to the case where the tip 51e of the driven side base 51a is not an inclined surface. Can be made. As a result, the drive side coupling 52 and the driven side coupling 51 can be easily connected.

  In the present embodiment, the tip of the driving claw 52b is hemispherical, and the tip 52c is dotted. For this reason, even if the drive side coupling 52 and the driven side coupling 51 are connected in a state where there is an axial misalignment, the tip 52c of the drive claw 52b is guided to the inclined surface 51c of the driven claw 51b and driven. The side coupling 51 can be connected to the drive side coupling 52. This is due to the following reason. That is, since the tip end portion of the driving claw 52b is hemispherical, the tip end 52c of the driving claw 52b becomes a point, so that the dotted tip end 52c of the driving claw 52b and the linear tip end 51d of the driven claw 51b intersect. There is nothing. As a result, the driven side coupling 51 can be reliably connected to the driving side coupling 52 without being pushed into the driving side even if the shaft is shifted and connected.

  FIG. 10 is a diagram illustrating a first modification of the coupling device according to the first embodiment. As shown in FIG. 10, the tip of the driving claw 52b may be a cone, or the tip of the driving claw 52b may be a triangular pyramid or a quadrangular pyramid, although not shown. In this way, the tip of the driving claw 52b can be made a point by making the tip of the driving claw 52b into a cone shape such as a cone. Therefore, even if the connection is attempted in a state in which the axis is misaligned, the tip 51d of the driven claw 51b and the tip 52c of the drive claw 52b do not intersect with each other, so that the driven coupling 51 can be satisfactorily connected to the drive side coupling 52. Can be linked. Further, even when the driving claw 52b hits the tip 51e of the driven base 51a when connecting the driving side coupling 52 and the driven side coupling 51, the shaft is formed by the surface forming the cone of the tip of the driving claw 52b. The driven coupling is guided so that the hearts are aligned.

  FIG. 11 is a diagram illustrating a second modification of the coupling device according to the first embodiment. As shown in FIG. 11, the driving claw 52b may be provided with an inclined surface 52c, and the tip of the driven claw 51b may be hemispherical. Moreover, as shown in the 3rd modification of the coupling apparatus of Example 1 shown in FIG. 12, it is good also as a cone and it is good also considering the front-end | tip 51c of the driven nail | claw 51b as a point. In this case, as shown in FIG. 13, the inclined surface 52c of the drive claw 52b is inclined in the circumferential direction and is also inclined from the drive shaft 64 side to the driven shaft 23 side from the outside to the inside. The tip 52d of the drive claw 52b of the drive side coupling 52 is made to coincide with the position of the tip of the drive side base. In the coupling device shown in FIG. 11, when the shaft centers are shifted and connected, the inclined surface 52c abuts against the tip 51e of the driven base 51a. Then, due to the inclination of the inclined surface 52c from the drive shaft 64 side to the driven shaft 23 side, the tip 51e of the driven side base 51a changes from the inner side to the outer side by the relative movement in the direction B in the drawing. Move relatively while being guided. As a result, the driving side coupling and the driven side coupling are fitted in a state where the axis of the driving side coupling is aligned with the axis of the driven side coupling. Further, since the tip 51c of the driven claw 51b is a point, the tip 51c of the driven claw 51b is connected to the drive claw 52 even when the axis of the drive side coupling 52 and the driven side coupling 51 is misaligned. It does not intersect with the tip 52d.

  FIG. 14 is a diagram illustrating a fourth modification of the coupling device according to the first embodiment. In the fourth modification, as shown in the figure, both the tip of the driving claw 52b and the tip of the driven claw 51b are conical, and both the tip 52c of the driving claw 52b and the tip 51c of the driven claw 51b are turned on. It is said. As described above, since the tips of both the driving claw 52b and the driven claw 51b are pointed, the tip 51c of the driving claw 52b and the tip 52c of the driven claw 51b cross each other even when the axis is shifted during the connection. There is no.

  Next, a coupling device 150 according to the second embodiment will be described with reference to FIGS. 15 to 20. In the coupling device of the second embodiment, the outer diameter φE2 of the outer peripheral surface 52f of the driving side base 152a of the driving side coupling 152 and the inner diameter φD2 of the inner peripheral surface 151g of the driven claw 151b of the driven side coupling 151 are driven. The size and tolerance are set such that the side coupling 151 and the driving side coupling 152 are fitted.

  15 to 17 are diagrams illustrating a coupling device 150 according to the second embodiment. As shown in the drawing, the tip of the driving claw 152b is hemispherical, and an inclined surface 151c is formed on the driven claw 151b. The inclined surface 151c of the driven claw 151b is inclined from the outside to the inside in the circumferential direction and from the drive shaft 164 side to the driven shaft 123 side. When the drive shaft side coupling 152 and the driven side coupling 151 are connected to each other with the shaft center shifted, the drive side base portion 152a abuts against the inclined surface 151c. When the drive base portion 152a is connected in a state where it abuts against the inclined surface 151c, the drive side base portion 152a is guided by the inclination from the outside to the inside of the inclined surface 151c, and the drive side base portion 152a is inserted into the driven side base portion. . As a result, the outer peripheral surface 151f of the drive side base 151a is fitted with the inner peripheral surface 152f of the driven claw 152b, and the drive side coupling 152 and the driven side coupling 151 are fitted. Also in the coupling device 150 of the second embodiment, the tip of the driving claw 152b is hemispherical, so that the tip is a point, so that the tip 51c of the driving claw 52b even if the shaft center is shifted during connection. And the tip 52c of the driven claw 51b do not intersect.

  Also in the coupling device 150 of the second embodiment, the tip portion of the driving claw 152b may be conical as in the first modification shown in FIG. Further, as in the second modification shown in FIG. 19, the driving claw has an inclined surface, and the tip of the driven claw has a hemispherical shape, or in a conical shape as in the third modification shown in FIG. Also good. Of course, both the tip of the driven claw and the tip of the drive claw may be conical or hemispherical.

  Next, a coupling device 250 according to the third embodiment will be described with reference to FIGS. FIG. 21 is a diagram illustrating a coupling device 250 according to the third embodiment. As shown in the figure, in the coupling device 250 of the third embodiment, the inner peripheral surface 251f of the driven base 251a is tapered so that the inner diameter decreases from the drive shaft side to the driven shaft side. At this time, the diameter φD1 ′ of the distal end 251e of the driven base 251a is larger than the outer diameter φE1 of the outer peripheral surface 252g of the drive claw 252b, and the diameter of the inner peripheral surface 251f on the drive shaft side is the outer peripheral surface of the drive claw 252b. The dimension φD1 to be fitted to 252g is set. When the shaft center is displaced at the time of connection, the outer peripheral surface 252g of the driving claw 252b is driven by the tapered inner peripheral surface 251f so that the shaft center of the driving coupling and the shaft center of the driven coupling are aligned. Guide into the base. And if the driven side coupling 251 moves relatively to the position connected with the drive side coupling 252, the outer peripheral surface 252g of the drive claw 252b and the inner peripheral surface 251f of the driven side base 251a are fitted. By adopting such a configuration, the tapered inner peripheral surface 251f gradually guides the driven side coupling in the direction in which the axis is aligned. On the other hand, in the coupling devices of the first and second embodiments, the leading end portion of the driving claw or the driven claw guides the driven side coupling in a direction in which the axis is aligned compared to the coupling device of the third embodiment. The axial length for guiding is short. Therefore, in the coupling devices of the first and second embodiments, the driven side coupling is suddenly moved in the direction in which the axes are aligned when coupled. For this reason, the insertion resistance during the time when the distal end portion of the driving claw or the driven claw guides the driven side coupling in the direction in which the axial centers are aligned is large. Therefore, it is necessary to push the driven side coupling strongly while the distal end portion of the driving claw or the driven claw guides the driven side coupling in the direction in which the axis is aligned. However, since the coupling device of the third embodiment gradually guides the driven side coupling in the direction in which the axis is aligned, the driven side coupling is guided in the direction in which the axis is aligned as in the first and second embodiments. Insertion resistance can be reduced during Therefore, the driven side coupling 51 and the driving side coupling 52 can be smoothly connected. Further, the outer peripheral surface 252g of the drive claw 252b and the inner peripheral surface of the driven side base are fitted at a predetermined position on the tapered inner peripheral surface, and when this is engaged, they cannot be moved further in the axial direction. Therefore, the unit can also be positioned in the axial direction by fitting the driven side coupling and the driving side coupling.

  FIG. 22 is a first modification of the coupling device 250 of the third embodiment. As shown in the figure, in the first modification, the outer peripheral surface 252f of the drive side base 252a is tapered so that the outer diameter increases toward the drive shaft side. In this first modification, the outer diameter φE2 on the drive shaft side of the drive side base 252a is set to a size and tolerance that fits with the inner diameter φD2 of the driven claw 251b, and when connected, the driven claw 251b is on the drive side. Guided by the tapered outer peripheral surface 252f of the base 252a, the driven coupling is relatively moved in the direction in which the axial centers are aligned. When the driving side coupling 252 is inserted to the position indicated by the dotted line in the figure, the inner peripheral surface 252g of the driven claw 251b and the outer peripheral surface 252f of the driving side base 252a are fitted, and the driving side coupling 252 The driven side coupling 251 is connected.

  FIG. 23 is a diagram illustrating a second modification of the coupling device 250 according to the third embodiment. As shown in the drawing, in the second modified example, the inner diameter of the driven claw 251b is tapered so that the inner diameter decreases toward the driven shaft 23, and the outer peripheral surface 252f of the drive side base 252a is directed to the drive shaft 64. As the outer diameter increases, the taper is formed. In this case, when the drive side coupling 252 and the driven side coupling 251 are coupled, the outer peripheral surface 251f of the drive side base 252a is guided by the tapered inner peripheral surface 251g of the driven claw 251b, while the drive side base 252a is inserted into the driven base. As shown by the dotted line in the figure, when the driving side coupling 252 moves relatively to the position where it is connected to the driven side coupling 251, the tapered inner peripheral surface 251g of the driven claw 251b and the outer periphery of the driving side base 252a The surface 252f is fitted with an axial center. As a result, the driving side coupling 252 and the driven side coupling 251 are fitted with each other in a state where there is an axial center.

  FIG. 24 is a diagram illustrating a third modification of the coupling device 250 according to the third embodiment. As shown in the figure, in this modification, the outer peripheral surface 252g of the driving claw 252b is tapered so that the outer diameter increases as it goes to the driving shaft 64, and the inner peripheral surface 251f of the driven side base 251a is directed to the driven shaft 23. The taper shape is such that the inner diameter decreases with the increase of the diameter. In this case, the drive-side base 252a is inserted into the driven-side base 251a while the tapered outer peripheral surface 252g of the drive claw 252b is guided by the inner peripheral surface 251f of the driven-side base 251a. When the driving side coupling relatively moves to the position indicated by the dotted line in the figure, the tapered outer peripheral surface 252g of the driving claw 252b is fitted with the inner peripheral surface 251f of the driven side base 251a.

  In the present embodiment, the driven shaft side coupling is configured to have a driven claw on the inner periphery of the cylindrical base, and the driving side coupling is configured to have a driving claw on the outer periphery of the columnar base. However, it is not limited to this. That is, the driven shaft side coupling may be configured to have a driven claw on the outer periphery of the columnar base, and the drive side coupling may be configured to have a driving claw on the inner periphery of the cylindrical base. In addition, the driven claw and the driving claw may be configured integrally with the base or may be separate.

  In the present embodiment, the coupling device of the present invention is used to connect the fixing unit 21 and the driving device 60, but the present invention is not limited to this. For example, the coupling of the present invention can be used to connect a developing unit having a developing roller and a driving device for rotating the developing roller. The coupling device of the present invention can also be used for connection between a photoconductor and a driving device for driving the photoconductor. Further, the present invention is also applied to the connection between the process units 1Y, 1M, 1C, and 1K shown in FIG. 3 and a driving device in the apparatus main body that drives the photosensitive member and the developing unit in the process unit. Can do. Furthermore, the coupling device of the present invention can be used not only for the image forming apparatus but also for other various machines and devices.

(1)
As described above, according to the coupling device of the present embodiment, when the driving side coupling as the second coupling and the driven coupling as the first coupling are connected, the tip of the driving claw as the second claw is the first claw. It can be prevented that the driving side coupling and the driven side coupling cannot be connected by hitting the tip of the driven claw. In addition, when the driven side coupling and the driving side coupling are coupled, the driven side coupling and the driving side coupling are fitted, so that the first rotation is performed when the driving side coupling and the driven side coupling are coupled. The axis of the driven shaft as the shaft and the axis of the drive shaft as the second rotation shaft can be aligned. Therefore, it is possible to suppress the rotation unevenness for each rotation due to the axial misalignment, and it is possible to suppress abnormal noise caused by the vibration of the driven unit caused by the rotation unevenness.
(2)
Further, according to the coupling device of the present embodiment, when the driving side coupling and the driven side coupling are connected, the driven side coupling is relatively relative to the driving side coupling in a direction in which the axis is aligned. It is possible to move to. Specifically, when the driving side coupling and the driven side coupling are connected, the fixing unit to which the driven coupling is attached is not positioned with respect to the apparatus main body to which the driving side coupling is attached. . As a result, when the drive side coupling and the driven side coupling are connected, the driven side coupling can be moved relative to the drive side coupling in a direction in which the axis is aligned. In this way, when the drive side coupling and the driven side coupling are connected, even if the axis is misaligned, the driven side coupling is aligned with the drive side coupling in the direction in which the axis is aligned. The drive side coupling and the driven side coupling can be coupled with each other being moved relative to each other with the shaft center.
(3)
Further, according to the coupling device of the first embodiment, the driving side coupling 52 and the driven side are fitted by fitting the inner peripheral surface 51f of the driven side base 51a as the first base and the outer peripheral surface 52g of the driving claw 52b. The coupling can be fitted.
(4)
Further, according to the coupling device of the third embodiment, the inner peripheral surface 252f of the driven side base portion 252a is tapered so that the inner diameter decreases toward the driven rotation shaft side. If the drive side base is inserted into the driven side base with the drive shaft and the driven shaft being misaligned, the outer peripheral surface of the drive claw contacts the tapered inner peripheral surface of the driven side base. When the drive side base is further inserted into the back of the driven base from the state in which the outer peripheral surface of the drive claw is in contact with the tapered inner peripheral surface of the driven base, the outer surface of the drive claw is tapered to the inner side of the driven base. The circumferential surface gradually guides in the direction in which the axes meet. When the drive side base moves to the coupling position, the outer peripheral surface of the drive claw and the inner peripheral surface of the driven side base are fitted in a state where the axis of the drive side coupling and the axis of the driven side coupling are aligned. Then, the driven side coupling and the driving side coupling are fitted. In such a configuration, since the shaft center is gradually aligned with the tapered inner peripheral surface at the time of connection, the resistance at the time of connection can be reduced, and the driven side coupling and the drive side coupling are smoothly connected. Can be made.
(5)
Further, the outer peripheral surface of the drive claw may be tapered so that the outer diameter increases toward the drive rotation axis. Even with such a configuration, it is possible to reduce the resistance when the driving side coupling and the driven side coupling are connected.
(6)
In addition, even if the outer peripheral surface of the driving side base and the inner peripheral surface of the driven claw are fitted as in the coupling device of the second embodiment, the driving side coupling and the driven side coupling are fitted. Can do.
(7)
Further, the outer peripheral surface of the drive side base may be tapered so that the outer diameter increases toward the drive shaft side. In this case, the driven claw is moved along the tapered outer peripheral surface of the drive side base, so that the drive side coupling is gradually moved in a direction in which the axes are aligned. Even in such a configuration, the resistance at the time of connection can be reduced, and the driven side coupling and the drive side coupling can be smoothly connected.
(8)
Further, the inner peripheral surface of the driven claw may have a tapered shape in which the inner diameter decreases toward the driven rotation shaft side. Even with such a configuration, it is possible to reduce the resistance when the driving side coupling and the driven side coupling are connected.
(9)
In addition, according to the image forming apparatus of the present embodiment, by providing the coupling device having the features (1) to (8), it is possible to suppress the rotation unevenness of the rotating body, and abnormal images such as banding. Can be suppressed.

1 is a schematic configuration diagram of a laser printer according to an embodiment. FIG. 3 is an enlarged configuration diagram showing a process unit for Y of the laser printer. The figure which shows a mode that a process unit is mounted | worn with an apparatus main body. FIG. 3 is a diagram illustrating a state in which a fixing unit and a transfer unit are pulled out from an apparatus main body. Sectional drawing which shows the drive connection part of a fixing unit. The figure which showed a mode that the driven coupling attached to the front-end | tip of the driven shaft of a fixing unit was connected with the drive side coupling provided in the apparatus main body side. 1 is a diagram illustrating one form of a coupling device according to Embodiment 1. FIG. The front view of the drive side coupling of the coupling apparatus of Example 1. FIG. The front view of the driven side coupling of the coupling of Example 1. FIG. The figure which shows the 1st modification of the coupling apparatus of Example 1. FIG. The figure which shows the 2nd modification of the coupling apparatus of Example 1. FIG. The figure which shows the 3rd modification of the coupling apparatus of Example 1. FIG. The perspective view which shows the shape of the inclined surface in the 2nd and 3rd modification of the coupling apparatus of Example 1. FIG. FIG. 6 is a diagram illustrating a coupling device according to a second embodiment. The front view of the drive side coupling of the coupling apparatus of Example 2. FIG. The front view of the driven side coupling of the coupling apparatus of Example 2. FIG. The figure which shows the 1st modification of the coupling apparatus of Example 2. FIG. The figure which shows the 2nd modification of the coupling apparatus of Example 2. FIG. The figure which shows the 3rd modification of the coupling apparatus of Example 2. FIG. The figure which shows the 4th modification of the coupling apparatus of Example 2. FIG. FIG. 6 is a diagram illustrating a coupling device according to a third embodiment. The figure which shows the 1st modification of the coupling apparatus of Example 3. FIG. The figure which shows the 2nd modification of the coupling apparatus of Example 3. FIG. The figure which shows the 3rd modification of the coupling apparatus of Example 3. FIG. The figure which shows an example of the conventional coupling apparatus. The figure which shows the other conventional coupling apparatus. Perspective view of another conventional coupling device The figure which shows a mode that a to-be-driven unit is attached to the back | inner side board of an apparatus. The figure which shows the mode of a connection with a drive side coupling and a driven side coupling when the axial center of a drive side coupling and a driven side coupling is the same in the conventional coupling apparatus. The figure which shows the mode of a connection with a drive side coupling and a driven side coupling when the axial center of a drive side coupling and a driven side coupling slip | deviates in the conventional coupling apparatus.

Explanation of symbols

1Y, M, C, K Process unit 2 Photoconductor 11 Transfer unit 21 Fixing unit 22 Case 23 Fixing roller shaft 26 Driven shaft 40 Developing devices 50, 150, 250 Coupling devices 51, 151, 251 Driven side couplings 52, 152 252 Drive side coupling 60 Drive device 62 Drive motor 64 Drive shaft 65 Electromagnetic clutch

Claims (9)

A first coupling having a cylindrical first base portion attached to the shaft end portion of the first rotation shaft and a plurality of first claws disposed on the inner peripheral surface of the first base portion, and an axis of the second rotation shaft A second coupling having a columnar second base attached to the end and a plurality of second claws disposed on the outer peripheral surface of the second base, the second coupling comprising the first cup Removably connected to the ring in the axial direction of the second coupling, and when the first coupling and the second coupling are connected, the first claws and the second claws are alternately positioned. A coupling device in which the second base is inserted into the first base so that the first pawl and the second pawl mesh with each other;
At least one tip of the first claw and the second claw as a point, and when the first coupling and the second coupling are connected, the axis of the first coupling and the axis of the second coupling A coupling device characterized in that the first coupling and the second coupling are fitted to each other. The coupling device of claim 1.
When the first coupling and the second coupling are connected, the first coupling is relatively movable with respect to the second coupling in a direction in which an axis is aligned. Coupling device. The coupling device according to claim 1 or 2,
The coupling device, wherein the first coupling and the second coupling are fitted by fitting the inner circumferential surface of the first base and the outer circumferential surface of each second claw. The coupling device according to claim 3.
A coupling device characterized in that the inner peripheral surface of the first base portion has a tapered shape with an inner diameter decreasing toward the first rotating shaft side. The coupling device according to claim 3 or 4,
A coupling device characterized in that the outer peripheral surface of each of the second claws has a tapered shape whose outer diameter increases toward the second rotating shaft. The coupling device according to claim 1 or 2,
The coupling device, wherein the first coupling and the second coupling are fitted by fitting the outer peripheral surface of the second base and the inner peripheral surface of each first claw. The coupling device of claim 6,
A coupling device, characterized in that the outer peripheral surface of the second base portion has a tapered shape with an outer diameter increasing toward the second rotating shaft. The coupling device according to claim 6 or 7,
A coupling device characterized in that the inner peripheral surface of each of the first claws has a tapered shape in which the inner diameter decreases toward the first rotating shaft.   A coupling device comprising the coupling device according to claim 1.

Images