JPH03181983A - Fixing structure of photosensitive drum - Google Patents

Abstract

PURPOSE:To hold and fix the photosensitive drum without shifting the center of the photosensitive drum from its drum shaft by providing a correction plate at a specific position of the outer periphery of a sleeve and providing a spring which pre-loads a ball bearing so that the ball bearing is locked to the correction plate. CONSTITUTION:Both ends of the photosensitive drum 10 engage drum chucks 13 and 15 and the ball bearing 24 is locked to the correction plate 1 with the preliminary pressure of a spring 2 before the engagement. Consequently, the inclination of the ball bearing 24 is corrected and a drum chuck 15 is held in a no-swing state and engages the end surface of the photosensitive drum 10. Then the compression of the spring 2 is started to separate the correction plate 1 from the ball bearing 24 and when the sleeve 25 stops, the engagement surfaces between both the ends of the photosensitive drum 10 and drum chucks 13 and 15 are applied with a press-contacting force by the spring 2, so that the photosensitive drum 10 is held and fixed. Consequently, the photosensitive drum 10 can be held and fixed while aligned with the drum shaft 11.

Description

[Detailed Description of the Invention] [Summary] Regarding a fixing structure for a photosensitive drum used in storage devices such as electrophotographic printers and copiers, the present invention relates to a fixing structure for a photosensitive drum used in storage devices such as electrophotographic printers and copiers, which holds the photosensitive drum without shifting the center of the photosensitive drum from the drum axis. One end of the photosensitive drum is engaged with one drum chuck on the drive side that is fixed to a drum shaft with one end fixed, and the photosensitive drum is slidably supported by the drum shaft. The other drum chuck supported by the sleeve via a ball bearing is configured to engage with the other end of the photosensitive drum and hold the photosensitive drum by pushing the sleeve to a predetermined position on the drum shaft. In the photosensitive drum fixing structure, a correction plate is provided at a predetermined position on the outer periphery of the sleeve for locking the inner and outer rings of the ball bearing on the one drum chuck side, and a correction plate is provided between the sleeve and the ball bearing. In addition, the cough ball bearing is preloaded so as to be locked to the correction plate, and a spring is provided that is compressed when the other end of the photosensitive drum and the other drum chuck are engaged by pushing the sleeve.

[Industrial application field]

The present invention relates to a fixing structure for a photosensitive drum used in recording devices such as electrophotographic printers and copiers.

The electrophotographic recording forming process will be explained below using an electrophotographic printer as an example.

The photosensitive drum is rotated in a predetermined direction, and its surface is uniformly charged by a charger. Next, the drum surface is irradiated with light according to recorded information to form an electrostatic latent image, and a developer is brought into contact with the photosensitive drum by a magnetic roller of a developing device to cause toner particles to adhere to the latent image on the drum surface. The toner image developed in this manner is transferred by a transfer device to a sheet of paper that is sent to a transfer position at a predetermined timing 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 it from the drum axis.

[Conventional technology]

FIG. 4 is a front view showing a conventional photosensitive drum fixing structure, and FIG. 5 is a detailed view of the main parts of FIG.
It is shown in the publication No. 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 driving 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 includes teeth 13c for enabling driving by a timing belt of a drive system (not shown).
It is supported by the drum shaft 11 via a bearing (not shown) near the frame 12a.

The lid member 14 includes a sleeve 25 that is slidably and rotatably supported by the drum shaft 11, a knob 27 that is fixed to an end 25a of the sleeve 25, and an 1E16 that rotatably fits into the sleeve 25. We are prepared.

A stopper pin 28 is embedded in the middle of the sleeve 25. As shown in FIG. 6, the shaft 11 is formed with grooves 31 in which the ends 28a and 28b of the stopper pin 28 are respectively engaged.

FIG. 6(a) is a front view showing the shape of the groove 31, and FIG. 6(c) is a developed view of FIG. 6(a). 32 is a spring provided between the lid 16 and the knob 27, and 33 is a washer fitted into the sleeve 25 so as to stop the lid 16 from moving to the left.

The drum chuck 15 is rotatably supported by a sleeve 25 via a ball bearing 24. 26a.

26b, the bearing 24 is connected to the sleeve 25. drum chuck 15
This is a washer provided to prevent it from coming out. Ball bearing 24 and disk 2 inserted into sleeve 25
A spring 17 is provided between the terminals 9 and 9. This spring 17 does not apply preload to the ball bearing 24, but when holding and fixing the photosensitive drum 10, which will be described later, the spring 17 moves the tapered portion 15a of the drum chuck 15 toward the end of the photosensitive drum 1o.
This is for pressing and engaging 0a.

The dummy drum 18 has an outer diameter that allows the photosensitive drum 10 to fit therein without rattling, and has a flange portion 18a.

It has 18d. The flange portions 18a and 18d are movably fitted onto the drum shaft 11.

A stopper 19 is fixed to the drum shaft 11 with a bolt 2o, and a spring 21 is provided between the stopper 19 and the flange portion 18a.

Mounting and fixing of the photosensitive drum 10 in this structure is performed as follows.

When mounting the photosensitive drum IO, the lid member 14 and drum chuck 15 are removed from the drum shaft 11, and the dummy drum 18 is pulled out to the right in FIG. 4 to the position indicated by the chain line.

In this state, the drum 18 has a flange portion 18a.
It is positioned by a set screw 22 (fixed to the drum shaft 11) and protrudes a predetermined amount from the opening 23 of the frame 12b. In this state, the photosensitive drum 10 is fitted onto the drum 18, their right ends are aligned, and the sleeve 25 is fitted onto the drum shaft 11 and pushed in. As a result, the tip of the sleeve 25 pushes the flange portion 18d,
The drum chuck 15 pushes the end surface 10a of the photosensitive drum 10. Thereafter, the stopper pin 28 comes into contact with the end of the drum shaft 11, and the ends 28a, 28b of the pin 28 fit into the end 31a of the groove 31, as shown in FIG. 6(b). When the knob 27 is rotated in the direction of the arrow A in FIG. 4 (clockwise when the knob 27 is viewed from the right in the same figure), the stopper pin 28 is guided by the groove 31 and rotates in the direction of the arrow in FIG. It moves, engages with the closing portion 31b of the groove 31, and is positioned. llb is the 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.
The end surface 10a is pressed by the biasing force of the spring 17 acting on the drum chuck 13, and the left end surface 10c of the drum is pressed against the end surface 10a.
The tapered portion 13a of the Finally, the lid 16 is locked to the frame 12b above the opening 23 by pin engagement or the like, and the photosensitive drum 10 is mounted.

Fixation is complete.

When cleaning, replacing, etc. the photoreceptor drum, the above procedure may be reversed.

[Problem to be solved by the invention]

As described above, the photosensitive drum is fixed by the drum chuck, but if the drum chuck 15 has an axial deflection, the center of the photosensitive drum 10 may shift from the drum axis 11 when the photosensitive drum 10 is fixed. In this case, photosensitive drum 1
Due to the zero deviation, the positional relationship of the developing units is shifted, resulting in printing problems.

This vibration of the photosensitive drum 10 is mainly due to the drum chuck 15.
This is due to the axial inclination of the ball bearing 24 that supports the rotation of the ball bearing 24. As shown in FIG. 7, in the ball bearing 24, the inner ring 24b must rotate relative to the outer ring 24a via the balls 24c, and a slight margin is provided between each part of the bearing, so there is no play. It will create a bond. For this purpose, Figure 7 (a)
) The ball bearing in its normal state is shown in Figure 7 (b) or (C).
As shown in , the outer ring 24a is inclined with respect to the inner ring 24b,
As a result, the ball bearing 24 will tilt. However, until now, little consideration has been given to the inclination of the ball bearing 24.

SUMMARY OF THE INVENTION An object of the present invention is to provide a photosensitive member fixing structure that can hold and fix a photosensitive drum without shifting the center of the photosensitive drum from the drum axis.

[Means to solve the problem]

FIG. 1 is an explanatory diagram of the principle of the present invention, in which 1 is a correction plate, 2
is a spring. The same reference numerals are used for parts common to the conventional ones, and 10 is a photosensitive drum, 11 is a drum shaft,
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 drum chuck 13 on the driving side supported by a fixed drum shaft 11, and a ball bearing 24 mounted on a sleeve 25 slidably supported by the drum shaft 11. The other end is engaged with the other drum chuck 15 supported through the drum chuck 15 to be held and fixed. These engagements are achieved by pushing the sleeve 25 into a predetermined position on the drum shaft 11 (the position shown in FIG. 1). Note that means for fixing the sleeve 25 pushed into the position and means for supporting the sleeve 25 on a frame (not shown) are provided separately.

The straightening 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 provided between the sleeve 25 and the ball bearing 24 to preload the ball bearing 24 so as to lock it to the correction plate 1 . This figure shows an example in which the ball bearing 24 is provided between a disc 29 inserted into the outer periphery of the sleeve 25 and the ball bearing 24. The spring 2 is moved between the photosensitive drum 10 and the drum chuck 1 by the pushing operation of the sleeve 25.
5 of 0 It is designed to be compressed by a predetermined amount at the time of payment.

[For production]

Mounting and fixing of the photosensitive drum 10 using this fixing structure is performed as follows.

When the photosensitive drum 10 is held between the drum chucks 13 and 15 and the sleeve 25 is fitted onto the drum shaft 11 and pushed in a predetermined amount, both ends of the photosensitive drum 10 engage with the drum chucks 13 and 15 during the pushing process. match. in this case,
Since the ball bearing 24 is locked to the straightening plate 1 by the preload force of the spring 2 before the engagement starts, the inclination of the ball bearing 24, which has been a problem in the past, is corrected, and the drum chuck I5
is held in a stable state and engaged with the end face of the photosensitive 1-ram 10. After that, when the sleeve 25 is further pushed in, the spring 2 starts to be compressed and the straightening plate 1 is pushed into the ball bearing 2.
4 and the sleeve 25 stops, the spring 2 applies pressure contact force to the engagement surfaces between both ends of the photosensitive drum 10 and each drum chuck 13, 15, and the photosensitive drum 10 is held and fixed.

1 In this way, the photosensitive drum 10 is
Since the drum chuck 15 is secured to the drum chuck 15, the photosensitive drum 10 can be held and fixed without shifting the center of the photosensitive drum 10 from the drum axis II, and printing failures due to vibration of the photosensitive drum are prevented.

In addition, when the photosensitive drum 10 is completely installed, the spring 2
Since the correction plate 1 is separated from the ball bearing 24 due to the compression, the ball bearing 24 can freely rotate.

Even in the conventional structure, a washer 26a and a spring 17, which are seemingly similar to the present invention, are provided, but the washer 26a restricts the movement of the ball bearing 24 and does not correspond to the inner and outer rings of the ball bearing, and the spring 17 does not apply preload to the ball bearing 24.

〔Example〕

The present invention will now be described in detail with reference to FIGS. 2 and 3.

FIG. 2 is a front view showing the fixing structure of the photosensitive drum of this example, and FIG. 3 is a detailed view of the main part of FIG.

The outline of the structure 2 function of this fixing structure is as described above with reference to FIG. 1, but a supplementary explanation will be given next.

The photosensitive drum 10 is mounted on the dummy drum 1 in the same way as before.
8 protrudes from the opening 23 of the frame 12b, the photosensitive drum 10 is fitted onto the dummy drum 18, and the sleeve 25 is pushed in by operating the knob 27. The holding and fixing of the photosensitive drum 10 by both drums 13 and 15 in this case has been described in detail with reference to FIG. Fixed. Therefore, printing problems caused by vibration of the photosensitive drum, which have been a problem in the past, can be prevented. Also,
When the mounting is completed, the ball bearing 24 is separated from the correction plate 1, so 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 with the groove 31 (not shown in FIGS. 2 and 3) formed in the drum shaft 11, as in the conventional case.

Furthermore, when the installation is completed, the sleeve 25 is supported by the bin engagement between the frame 12b and the lid 16 above the opening 23, and thereby the drum shaft is fitted into the sleeve 25.
The free end of 1 is supported.

〔Effect of the invention〕

As described above, according to the present invention, the photosensitive drum can be held and fixed so that its center is aligned with the drum axis, and printing failure can be prevented from occurring.

[Brief explanation of drawings]

Fig. 1 is a diagram explaining the principle of the present invention, Fig. 2 is a front view showing the fixing structure of a photosensitive drum according to an embodiment of the present invention, Fig. 3 is a detailed view of the main part of Fig. 2, and Fig. 4 is a conventional A front view showing the fixing structure of the photosensitive drum, FIG. 5 is a detailed view of the main part of FIG. 4, FIGS. 6(a) and (b) are explanatory diagrams of the shape of the grooves formed in the drum shaft of FIG. 4, Figures 7 (a), (b), and (C) are explanatory diagrams of ball bearings, and in Figure 4, ■ is a straightening plate, 2 is a spring, 10 is a photosensitive drum, 11 is a drum shaft, and 13.15 is a drum. A chuck, 24 is a ball bearing, and 25 is a sleeve.

Claims (1)

[Scope of Claims] One end of the photosensitive drum (10) is engaged with one drum chuck (13) on the driving side supported by the drum shaft 11 with one end fixed, and the drum chuck (10) is slidable on the drum shaft (11). The other drum chuck (15) supported by a movably supported sleeve (25) via a ball bearing (24) is pushed into the drum shaft (11) by pushing the sleeve (25) to a predetermined position on the drum shaft (11). The photosensitive drum (10) is engaged with the other end of the photosensitive drum (10).
In the photosensitive drum fixing structure configured to hold the one drum chuck (13), the inner and outer rings of the ball bearing (24) are held at predetermined positions on the outer periphery of the sleeve (25).
A straightening plate (1) is provided for locking on the side, and a straightening plate (1) is provided between the sleeve (25) and the ball bearing (24) so as to lock the ball bearing (24) to the straightening plate (1). By preloading the sleeve (25) and pushing the sleeve (25), the edge of the photosensitive drum (10) and the drum chuck (15)
) is provided with a spring (2) that is compressed when engaged.