JPS61124966A - Driving device for rotating body - Google Patents

Abstract

PURPOSE:To improve durability and to maintain always stable performance by providing a driving means for driving a rotating body in the axial direction thereof, clutch means for connecting and disconnecting the driving between a driving source and the driving means and control means for controlling the operation timing of the clutch means. CONSTITUTION:Image distortion and uneven pitch arise when a photosensitive body is moved back and forth in the axial direction during image formation. A drum 11 is therefore moved back and forth before the image formation and is rotated only in the peripheral direction during the image formation. The driving force of a motor 13 is transmitted to gears 19, 20 to rotate a shaft 21 when a clutch 24 is disengaged during preliminary rotation, but gears 22, 4 do not rotate as the clutch 24 is held disengaged. However a gear 2 is rotated by way of a gear 23 and therefore a bearing 5 contacts with a cam surface 2a and the drum 11 oscillates in the axial direction. The clutch 24 is engaged after the drum 1 is set in the position having no deviation upon completion of the preliminary rotation, then the driving force of the motor 18 is transmitted to the gears 19, 20, the shaft 21 and the gear 22 and a working gear 4 is rotated.

Description

[Detailed Description of the Invention] <Industrial Application Scope> The present invention includes a mechanism for rotationally driving copying machines, printing machines, recording machines, and their low-rotation bodies (drum-shaped or belt-shaped photoreceptors, etc.). A rotating body drive device for a machine, etc. (hereinafter referred to as a copying machine, etc.), in particular a rotating body drive device that moves the corresponding circumferential surface of a rotating body in the axial direction so that it corresponds to a position without deviation. be.

<Prior Art> Conventionally, in this type of apparatus, for example, in an electrophotographic recording apparatus, a cleaner blade for removing toner remaining on the photosensitive drum after transfer is pressed against the drum surface. Since the positional relationship of the photosensitive drum in the axial direction of the drum is fixed, the photosensitive drum is always rubbed at the same place, and scratches on the cleaner blade or foreign matter stuck between the cleaner blade and the photosensitive drum may stick to the photosensitive drum. There was a problem in that the scratches gradually expanded and the photosensitive drum deteriorated more quickly.

<Object of the Invention> The object of the present invention is to eliminate the above-mentioned drawbacks, move the rotating body in the axial direction, prevent fatigue and deterioration of the same part of the rotating body, improve durability, and constantly improve durability. The purpose is to maintain stable performance.

<Example> Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 shows an example of the configuration of the rotating body driving device of the present invention,
Here, 1 is a photosensitive drum, 2 is a gear flange having a cam surface 2a formed on one side, a pole bearing 3 is press-fitted into the inner periphery of the gear flange 2, and the outer periphery of the gear 7 flange 2 is fitted with the photosensitive drum 1. Reference numeral 4 denotes an operating gear, and a pole bearing 5 is disposed on the end face of the operating gear 4 on the gear flange 2 side, and the outer ring of the pole bearing 5 is in contact with the cam surface 2a to form a cam pairing with the cam surface 2a. form a mechanism,
The pole bearing 5 is made freely rotatable around the shaft 6 fixed to the end face of the operating gear 4 (see Fig. 2).

Furthermore, a pawl bearing 7 is press-fitted into the inner periphery of the operating gear 4. 8 is a drum shaft that supports the photosensitive drum 1;
It is fixed to the left frame 10 of the main body via a shaft support 9. Another flange 11 is fitted to one end of the photosensitive drum 1 opposite to the gear flange 2, and a pole bearing 12 is also press-fitted into the inner periphery of this flange 11. , 13 is a compression spring that presses the above-mentioned cam surface 2a against the outer ring of the pole bearing 5, and pushes the photosensitive drum 1 to the left in the drawing via the collar 14. A housing 15 houses the compression spring 13 and the collar 14, and is fixed to the centering plate 16. 17 is the right frame of the main body to which the centering plate 16 is fixed. The spring force of the compression spring 13 is received via the pole bearing 12, the photosensitive drum 1, the cam surface 2a, the pole bearing 5, and the right end face of the shaft support 9 against which the end face of the inner ring of the pole bearing 7 is abutted. .

Next, the driving relationship will be explained. Reference numeral 18 is a motor that rotates the photosensitive drum 1, and drives the gear flange 2 integrated with the photosensitive drum 1 via gears 19 and 20, a gear shaft 21, and a gear 23. The gear 22 also includes a clutch 24.
is press-fitted.

FIG. 2 shows the cam mechanism shown in FIG. 1 expanded in the circumferential direction. Here, the cam surface 2a has a sine curve-like uneven shape corresponding to two periods. A pair of pole bearings 5 abutting the pole bearings 2a are provided at opposite positions offset by 180'.

A photoreceptor 1 of a copying machine or the like performs a rotation operation called pre-rotation before normal image formation. The pre-rotation is performed until predetermined parts within the copying machine are set to a constant temperature, and the period until completion varies depending on the temperature of the machine before the power is turned on.

Further, when the photoreceptor is reciprocated in the axial direction during the image forming process, image distortion, pitch unevenness, etc. occur. Therefore, in this embodiment, the drum 11 is reciprocated during the image forming process, and only rotates in the circumferential direction during image forming.

If the clutch 24 is disengaged during forward rotation, the motor 1
The driving force of 8 is transmitted to gears 19 and 20 and rotates shaft 21, but since clutch 24 is disengaged, gear 2
2.4 does not rotate. However, since the gear 2 rotates through the gear 23, the bearing 5 contacts the cam surface 2a, and the drum 11 swings in the axial direction.

Since the pre-rotation time varies depending on the environment of the machine before the power is turned on, the time from the start to the end of rotation is unspecified. Therefore, by reciprocating the drum 11 only during this period, it is possible to set the drum 11 at a position with no deviation in the axial direction.

After the pre-rotation is completed and the drum 1 is set at a position without deviation, when the clutch 24 is connected, the driving force of the motor 18 is transmitted to the gears 19, 20, the shaft 21, and the gear 22, and the driving force is transferred to the operating gear 4. rotates.

Since the operating gear 4 and gear flange 2 rotate periodically,
There is no speed difference between the cam 5 and the cam surface 2a, and the drum 1
1 remains fixed in the axial direction without any deviation,
The image forming process is performed by rotation.

When the image forming process is completed, the power is turned off, and the power is turned on again to use the copying machine.

Pre-rotations are performed until warm-up is complete.

The time it takes to complete the pre-rotation varies depending on the temperature before the power is turned on, so the axial position of the drum 11 will always be different from the previous image formation.

<Effects of the Invention> As described above, according to the present invention, it is possible to prevent fatigue and deterioration of the same part of the rotating body, and by improving durability, stable performance can be maintained at all times.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an example of the configuration of the rotary body drive device of the present invention, and FIG. 2 is a developed view showing the configuration of the cam mechanism of the rotary body drive device of FIG. 1 expanded in the circumferential direction. It is. 1--One photosensitive drum 2--One gear flange 2a
---Cam surface 4-1-1 Working gear 5-----Pole bearing 8--Drum shaft 13---1 Compression spring 24--
---Electromagnetic clutch diagram 2

Claims (1)

[Scope of Claims] A cylindrical rotating body, a driving source that rotationally drives the rotating body, a driving means that moves the rotating body in its axial direction, and a driving connection between the driving source and the driving means. A rotating body drive device comprising: a clutch means for releasing the clutch means; and a control means for controlling the timing of operation of the clutch means.