JP2520749B2 - Photosensitive drum fixing structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Overview] Regarding a fixing structure of a photosensitive drum used in a storage device such as an electrophotographic printer and a copying machine, the photosensitive drum is held and fixed without shifting the center of the photosensitive drum from a drum shaft. For the purpose of making it possible, one end of the photosensitive drum is engaged with one of the driving side drum chucks supported by the drum shaft having one end fixed, and the sleeve is slidably supported by the drum shaft. A ball bearing consisting of an inner ring, an outer ring, and a ball is slidably supported on the sleeve, and the other drum chuck supported by the sleeve via the ball bearing is pushed into the drum shaft to a predetermined position. In the fixing structure of the photosensitive drum configured to be engaged with the other end of the photosensitive drum to hold the photosensitive drum, a predetermined position on the outer periphery of the sleeve A correction plate for locking the inner ring and the outer ring of the ball bearing on the side of the one drum chuck, and locking the ball bearing to the correction plate between the sleeve and the inner ring of the ball bearing. Pre-loading so that the end portion of the photosensitive drum and the other drum chuck are engaged by pushing in the sleeve, with respect to the sleeve,
A spring provided so as to be compressed is provided via the ball bearing so as to urge the other drum chuck in the direction of pressing the end portion of the photosensitive drum.

[Industrial applications]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photosensitive drum fixing structure for use in a recording device such as an electrophotographic printer or a copying machine.

The electrophotographic recording forming process will be described below by taking an electrophotographic printer as an example.

The photosensitive drum is rotated in a predetermined direction, and its surface is uniformly charged by a charger. Then, the drum surface is irradiated with light corresponding to the recording information to form an electrostatic latent image, and the developer is brought into contact with the photosensitive drum by the magnet roller of the developing device to adhere toner particles to the latent image on the drum surface. The toner image developed in this manner is transferred by a transfer device onto a sheet that is sent to a transfer position in synchronization with the rotation of the photosensitive drum.

In such a photosensitive drum for recording information, it is necessary to fix the center of the drum without shifting the drum center.

[Conventional technology]

FIG. 4 is a front view showing a conventional photosensitive drum fixing structure,
FIG. 5 is a detailed view of an essential part of FIG. 4, and the details thereof are shown in Japanese Patent Application Laid-Open No. 62-272290 proposed by the present applicant. The outline of this structure is as follows.

In the figure, 10 is a photosensitive drum, 11 is a drum shaft, 13 is one drum chuck (flange) on the drive side, 14 is a lid member, 15 is the other drum chuck (flange), and 18 is a dummy drum.

The drum shaft 11 has one end 11a fixed to one frame 12a.

The drum chuck 13 has teeth 13c for enabling driving by a timing belt of a drive system (not shown), and is supported by the drum shaft 11 near a frame 12a via a bearing (not shown).

The lid member 14 includes a sleeve 25 slidably and rotatably supported by the drum shaft 11, a knob 27 fixed to an end 25a of the sleeve 25, and a lid 16 rotatably fitted to the sleeve 25. Is equipped with. A stopper pin 28 is embedded in the sleeve 25. As shown in FIG. 6, the shaft 11 is formed with a groove 31 with which the ends 28a and 28b of the stopper pin 28 engage. 6 (a) is a front view showing the shape of the groove 31, and FIG. 6 (b) is a development view of FIG. 6 (a). 32 is a spring provided between the lid 16 and the knob 27, 33
Is a washer fitted in the sleeve 25 so as to lock the movement of the lid 16 to the left.

The drum chuck 15 is rotatably supported by the sleeve 25 via a ball bearing 24. 26a and 26b, the bearing 24 is the sleeve 2
5. A washer provided to prevent the drum chuck 15 from coming out. A spring 17 is provided between the ball bearing 24 and the disc 29 inserted in the sleeve 25. This spring 17 does not apply a preload to the ball bearing 24, but the taper portion 15a of the drum chuck 15 is fixed to the end portion 10a of the photosensitive drum 10 at the time of holding and fixing the photosensitive drum 10, which will be described later.
It is for pressing and engaging with.

The dummy drum 18 has an outer diameter such that the photosensitive drum 10 fits without rattling, and has flange portions 18a and 18d.
The flange portions 18a and 18d are movably fitted to the drum shaft 11. Reference numeral 19 is a stopper fixed to the drum shaft 11 by a bolt 20, and a spring 21 is provided between the stopper 19 and the flange portion 18a.

The mounting and fixing of the photosensitive drum 10 in this structure are performed as follows.

When mounting the photosensitive drum 10, the lid member 14 and the drum chuck 15 are removed from the drum shaft 11 and the dummy drum is used.
Pull 18 to the right in Fig. 4 to the position indicated by the chain line. In this state, the dummy drum 18 has the flange portion 18a and the set screw 22
It is positioned by the engagement (fixed to the drum shaft 11) and projects a predetermined amount from the opening 23 of the frame 12b. In this state, the photosensitive drum 10 is fitted into the dummy drum 18, the right ends of the both are aligned, and the sleeve 25 is fitted into the drum shaft 11 and pushed in. As a result, the tip of the sleeve 25 pushes the flange portion 18d, and the drum chuck 15 causes the photosensitive drum 10 to move.
Press the end face 10a of After that, the stopper pin 28 comes into contact with the end portion of the drum shaft 11, and the end portions 28a and 28b of the pin 28 come to the sixth position.
As shown in FIG. 3B, the groove 31 is fitted into the end 31a. When the knob 27 is rotated in the direction of arrow A in Fig. 4 (clockwise when the knob 27 is viewed from the right side in Fig. 4), the stopper pin is rotated.
28 is guided by the groove 31 and moves in the direction of the arrow in FIG.
The closed portion 31b of 31 is engaged and positioned. 11b is an end face of the drum shaft 11. During this time, the dummy drum 18 pushed by the sleeve 25 moves to the position shown by the solid line in FIG.
15a presses the end surface 10a by the urging force of the spring 17 acting on the drum chuck 15 to engage the left end surface 10c of the drum with the taper portion 13a of the drum chuck 13. Finally, the lid 1
6 is locked to the frame 12b above the opening 23 by engagement or the like, and the mounting and fixing of the photosensitive drum 10 is completed.

When cleaning or replacing the photoconductor drum, the procedure reverse to the above procedure may be performed.

[Problems to be Solved by the Invention]

As described above, the photosensitive drum is fixed by the drum chuck, but when the drum chuck 15 has axial deflection, the center of the photosensitive drum 10 is displaced from the drum shaft 11 when the photosensitive drum 10 is fixed. In this case, since the positional relationship of the developing device is displaced due to the shake of the photosensitive drum 10, printing failure occurs. The shake of the photosensitive drum 10 is mainly due to the axial inclination of the ball bearing 24 that supports the rotation of the drum chuck 15. As shown in FIG. 7, in the ball bearing 24, the inner ring 24b is the ball 2
Since it must rotate with respect to the outer ring 24a via 4c, and there is some margin between bearing parts, rattling will occur. Therefore, as shown in FIG. 7 (b) or 7 (c), the ball bearing in the normal state shown in FIG. 7 (a) has the outer ring 24a inclined with respect to the inner ring 24b, and as a result, the ball bearing.
24 will tilt. However, until now, the inclination of the ball bearing 24 has not been considered so much.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a fixing structure for a photoconductor that can hold and fix the photoconductor drum without shifting the center of the photoconductor drum from the drum shaft.

[Means for solving the problem]

FIG. 1 is a diagram for explaining the principle of the present invention, in which 1 is a straightening plate,
2 is a spring. The same reference numerals are used for the members common to the conventional ones, 10 is a photosensitive drum, 11 is a drum shaft, and 13
Is one drum chuck, 15 is the other drum chuck,
24 is a ball bearing and 25 is a sleeve.

The photosensitive drum 10 has one end engaged with one driving-side drum chuck 13 supported by a drum shaft 11 having one end fixed, and a ball bearing 24 on a sleeve 25 slidably supported on the drum shaft 11. The other end is engaged with and held and fixed to the other drum chuck 15 supported via. These engagements are realized by pushing the sleeve 25 to a predetermined position (the position shown in FIG. 1) of the drum shaft 11. The means for fixing the sleeve 25 pushed into this position and the means for supporting the sleeve 25 on a frame (not shown) are provided separately.

The correction plate 1 is for locking the inner and outer rings of the ball bearing 24 on the left side (drum chuck 13 side), and is provided at a predetermined position on the outer periphery of the sleeve 25.

The spring 2 is for preloading the ball bearing 24 so as to be locked to the correction plate 1, and is provided between the sleeve 25 and the ball bearing 24. This drawing shows an example provided between the disc 29 and the ball bearing 24 inserted into the outer periphery of the sleeve 25. The spring 2 is designed to be compressed by a predetermined amount when the photosensitive drum 10 and the drum chuck 15 are engaged by the pushing operation of the sleeve 25.

[Action]

Mounting and fixing of the photosensitive drum 10 by this fixing structure are performed as follows.

When the photosensitive drum 10 is held between the drum chucks 13 and 15 and the sleeve 25 is engaged with the drum shaft 11 and pushed in by a predetermined amount, both ends of the photosensitive drum 10 engage with the drum chucks 13 and 15 during the pushing. To meet. In this case, since the ball bearing 24 is engaged with the correction plate 1 by the preload of the spring 2 before the engagement is started, the inclination of the ball bearing 24, which has been a problem in the past, is corrected and the drum chuck 15 is The end surface of the photosensitive drum 10 is engaged while being held in a stable state. When the sleeve 25 is further pushed in thereafter, the ball bearing 24 moves relative to the sleeve 25 and moves away from the correction plate 1. Further, the spring 2 is compressed by the relative movement of the ball bearing 24 and the sleeve 25, and when the sleeve 25 stops, the photosensitive drum
The photosensitive drum 10 is held and fixed by applying a pressing force by the spring 2 to the engaging surfaces of both ends of 10 and the drum chucks 13 and 15.

In this way, the ball bearings should be
And the drum chuck 15 are engaged with each other, the photosensitive drum 10 can be held and fixed without shifting the center of the photosensitive drum 10 from the drum shaft 11, and printing failure due to the shake of the photosensitive drum can be prevented.

Further, when the photosensitive drum 10 is completely attached, the spring 2
Since the straightening plate 1 is separated from the ball bearing 24 by the compression of
The ball bearing 24 can rotate freely.

Even in the conventional structure, the washer 26a and the spring 17 similar to those of the present invention are provided, but the washer 26a is used in the ball bearing 2.
4 does not correspond to the inner and outer races of the ball bearing, and does not support the inner and outer races of the ball bearing.
24 does not preload the whole.

〔Example〕

Embodiments of the present invention will be described below with reference to FIGS. 2 and 3.

FIG. 2 is a front view showing the fixing structure of the photosensitive drum of this example,
FIG. 3 is a detailed view of the main parts of FIG. 2, and the same reference numerals are used for the members common to the conventional and FIG.

The outline of the structure and operation of this fixing structure is as described above with reference to FIG. 1, and a supplementary explanation will be given next.

The photosensitive drum 10 is mounted on the dummy drum 18 as in the past.
The dummy drum 1 by projecting from the opening 23 of the frame 12b.
Fit the photosensitive drum 10 to 8 and operate the knob 27 to
Press 5 to perform. The holding and fixing of the photosensitive drum 10 by the both drums 13 and 15 in this case has been described in detail with reference to FIG. 1, and therefore the description thereof will be omitted here, but the photosensitive drum 10 is held without being displaced from the drum shaft 11. Fixed. Therefore, it is possible to prevent the print failure due to the shake of the photosensitive drum, which has been a problem in the related art. In addition, the ball bearing 24
Is separated from the straightening plate 1, the rotation of the ball bearing 24 is not hindered.

When the mounting is completed, the sleeve 25 is fixed by engaging the stopper pin 28 and the groove 31 (not shown in FIGS. 2 and 3) formed in the drum shaft 11 as in the conventional case.

When the mounting is completed, the sleeve 25 is supported by the pin engagement between the frame 12b and the lid 16 above the opening 23,
As a result, the free end of the drum shaft 11 fitted in the sleeve 25 is supported.

〔The invention's effect〕

As described above, according to the present invention, the photosensitive drum can be held and fixed so that the center of the photosensitive drum is aligned with the drum shaft, and the occurrence of printing failure can be prevented.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory view of the principle of the present invention, FIG. 2 is a front view showing a fixing structure of a photosensitive drum of an embodiment of the present invention, and FIG. 3 is a detailed view of an essential part of FIG. FIG. 4 is a front view showing a conventional fixing structure of a photosensitive drum, FIG. 5 is a detailed view of an essential part of FIG. 4, and FIGS. 6 (a) and 6 (b) are formed on the drum shaft of FIG. 7A, 7B, and 7C are explanatory views of a ball bearing, in which 1 is a straightening plate, 2 is a spring, 10 is a photosensitive drum, and 11 is a drum shaft. , 13 and 15 are drum chucks, 24 is a ball bearing, and 25 is a sleeve.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor City position Kazumasa Saho No. 35, Saho, Kato-gun, Hyogo Prefecture (No address) Inside Fujitsu Peripheral Machinery Co., Ltd. (56) References JP 62-67580 (JP, A) JP 62-272290 (JP, A) Actual opening 64-17561 (JP, U) Actual opening Hei 1-103859 (JP, U) Actual opening Sho 53-4941 (JP, U) Japanese Patent Publication 46-27040 (JP, B2)

Claims (1)

(57) [Claims] 1. An end of a photosensitive drum (10) is engaged with one drum chuck (13) on the drive side supported by a drum shaft (11) having one end fixed thereto, and the drum shaft (11) is attached to the drum shaft (11). Inner ring (24b), outer ring (24a), and ball (24c) on a sleeve (25) slidably supported
A ball bearing (24) made of a slidable material, and the other drum chuck (15) supported by the sleeve (25) via the ball bearing (24) and the sleeve (25). A photosensitive drum fixing structure configured to hold the photosensitive drum (10) by engaging the other end of the photosensitive drum (10) by pushing the drum shaft (11) to a predetermined position. A correction plate (1) for locking the inner ring (24b) and the outer ring (24a) of the ball bearing (24) on the side of the one drum chuck (13) is provided at a predetermined position on the outer circumference of 25), and Inner ring (24b) of the sleeve (25) and the ball bearing (24)
Between them, the ball bearing (24) is preloaded so as to engage with the correction plate (1), and the end of the photosensitive drum (10) and the other drum chuck are pushed by pushing the sleeve (25). When engaging (15), the other drum chuck (15) is inserted into the sleeve (25) through the ball bearing (24).
A fixing structure for a photosensitive drum, characterized in that a spring (2) is provided for urging the end portion of the photosensitive drum (10) in a direction to press the end.