JPS6267580A - Supporting device for photosensitive drum - Google Patents

Abstract

PURPOSE:To prevent a photosensitive drum being eccentrically fitted on a flange by setting the abutting surface of at least one out of two flanges to a part of a curved surface in a photosensitive drum supporting device which abuts on tapered parts of a cylindrical photosensitive body having the tapered parts on both end inner surfaces and includes a pair of rotatable flanges. CONSTITUTION:A ball bearing 12 is fitted on the front and rear part of a drum spindle 11, and the flange 13 is pivotally fitted. The abutting surface of at least one out of flanges 13 abutting on a tapered surface 14a formed on both inner end surfaces of the cylindrical photosensitive drum 14 is set to arbitrarily curved surface 13a. Even if the flange 13 tilts on a plane passing through the center of the bearing 12 due to the play of the drum spindle 11 and the inner surface of the bearing 12, the photosensitive drum 14 is not made eccentric, because the part where the tapered surface 13a of the flange 13 abuts on each other is a circular contact.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a photosensitive drum support device for an electrophotographic copying machine.

(Conventional technology) FIG. 4 shows a conventional photosensitive drum support device.

That is, two ball bearings 2, 3 and two dry bearings 4, 5 are attached to the front part of the fixed drum shaft 1, and a flange 6.7 is rotatably attached to the rear flange 7. A pulley 8 for use is screwed, and both flanges 6.7 are formed with tapered surfaces 5a, 6a having the same angle as the inner surface of both ends of the photosensitive drum 9.
, 6a sandwich the photoreceptor drum 9, and the photoreceptor drum 9
The core of the engine is brought out and the drive is transmitted. spring 10
By pressing the flange 6.7 against the photosensitive drum 9 using the flange 6, the frictional force of the tapered contact portion is increased and reliable driving is obtained. If the two bearings are arranged in front of each other in this way, it is possible to prevent the flange from tilting, but the structure becomes complicated and costs increase. Therefore, as shown in Fig. 5, flanges shaped like cut dry bearings 4 and 5 have been conventionally used in some models, but due to play in the drum shaft 1, the flanges 6 and 7 are set in the N position while being tilted. I often put it away.

In other words, the inner surfaces of both ends of the photoreceptor drum 9 and the tapered surfaces 6a, 7a of the flange 6°7 are not aligned and the photoreceptor drum 9 is rotated eccentrically. There was a problem in that it had a negative effect on the copying process up to the time of copying.

(Objective) An object of the present invention is to prevent a photoreceptor drum from being eccentrically attached to a flange with a simple structure, and to reduce processing costs by making high processing precision of the flange unnecessary.

(W) In order to achieve the above object, the present invention includes a cylindrical photoreceptor having a tapered portion on the inner surface of both ends, and abutting on the tapered portion,
and a pair of rotatable flanges, characterized in that a contact surface of at least one of the flanges that comes into contact with both tapered portions of the photoreceptor is a part of a curved surface. It is said that

By the way, if you think about the taper of the flange, you will find that it is necessary for the rear flange, but not necessarily for the front flange. This is because the rear side should be in contact with the drum over as large an area as possible in order to transmit the drive, but the role of the front side is to press the drum backward so that the frictional force between the rear flange and the drum is large. This is because all you have to do is bring out your core. In other words, the front flange does not need the same taper as the rear.

The embodiment shown in FIGS. 1 to 3 will be specifically described below. Drum shaft 1 fixed in Figures 1 and 2
Ball bearings 12 are attached to the front and rear of 1,
A flange 13 is rotatably pivoted. Reference numeral 14 denotes a cylindrical photoreceptor drum, and the contact surface of at least one of the flanges 13 that comes into contact with tapered surfaces 14a formed on the inner surfaces of both ends thereof is an arbitrary curved surface 13a. A spring 15 presses the flange 13 against the photosensitive drum 14. The flange 13 on the front side can be freely moved in the thrust direction for replacing the photosensitive drum 14. This curved surface 13
a is the center of the bearing 12 of the flange 13 as shown in FIG.
It may also be part of a spherical surface centered at .

Next, the effect will be explained. Even if the flange 13 is tilted in a plane passing through the center of the bearing 12 due to play between the drum shaft 11 and the inner surface of the bearing 12, the contact portion between the tapered surface 14a of the photoreceptor drum 14 and the curved surface 13a of the flange 13 is in circular contact, so that the photoreceptor The drum 14 will not become eccentric. This contact may be anywhere on the drum taper. Therefore, this surface 1
The processing accuracy of 3a may be rough. The cross-sectional shape perpendicular to the center line of the flange 13 needs to be a perfect circle, but such a circle can be easily obtained by rotation processing using a lathe or the like.

(Effects) According to the present invention, in a photoreceptor drum support device comprising a cylindrical photoreceptor having a tapered portion on the inner surface at both ends and a pair of flanges that abut the tapered portion and are rotatable, Since the abutment surface of at least one of the flanges that abuts both the taper parts is a part of a curved surface, the simple structure prevents the photoreceptor drum from being eccentrically attached to the flange, and eliminates the need for high-precision machining of the flange. If necessary, processing costs can be reduced.

[Brief explanation of drawings]

Fig. 1 is a front sectional view of one embodiment of the present invention, Fig. 2 is an enlarged front sectional view of the flange contact part of Fig. 1, Fig. 3 is an explanatory diagram of another embodiment of the flange curved surface, and Fig. 4 is a conventional FIG. 5 is a front sectional view of the device when the flange of FIG. 4 is installed eccentrically. 11...Drum shaft 12...Bearing 13...Flange 13a...Curved surface 14...Photosensitive drum 14a...Tapered surface 15...Spring patent applicant Rico Co., Ltd. -,・'°□'1 Deputy Director Sadao Ito 1ゝ・、１、・、Fig. 1 Fig. 2 14σ 14 Fig. 3 Fig. 4 Fig. 5

Claims (3)

[Claims] (1) A photoconductor drum support device comprising a cylindrical photoconductor having tapered portions on the inner surface of both ends, and a pair of flanges that abut the tapered portions and are rotatable; A photosensitive drum support device characterized in that at least one contact surface of both flanges that contact each other is a part of a curved surface. (2) A patent characterized in that the shape of the contact surface of the flange is a part of a spherical surface centered at a point on the drum axis, and the center substantially coincides with the center of the bearing of the flange. A photosensitive drum support device according to claim 1. (3) The photosensitive drum support device according to claim 1 or 2, wherein at least one of the flanges is movable in the thrust direction with respect to the main body of the copying machine.