JP2000249210A - Gearing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gearing apparatus, which is capable of reducing a gear ratio by a simple construction and less in the number of part items, and more particularly to a gearing apparatus of a developing apparatus which is capable of surely rotating at a low speed an agitating means arranged in the developing apparatus by a simple construction. SOLUTION: A gearing apparatus is driven by a part of an intermediate gear of a driving system in a developing roller. The driven gear is provided with an intermittent gear 19. Teeth of the intermittent gear 19 intermittently drive a slave gear 20. The intermittent gear 19 has at least two continuously pitched teeth, one of which firstly contacting to the teeth of the slave gear 20 is cut in an arc or plain-like shape at a pitch diameter thereof, whereas the teeth of the slave gear 20 are sharpened.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gear device capable of greatly reducing the gear ratio with a simple structure, and more particularly, to stirring a toner stored in a developing device such as a copying machine or a printer with a simple structure. The present invention relates to a gear device used for an electrophotographic apparatus capable of performing the above-described operations.

[0002]

2. Description of the Related Art A developing device incorporated in an image forming apparatus such as a copying machine or a printer forms, for example, a toner as a one-component developer in a uniform layer on a peripheral surface of a developing roller in the apparatus. In addition, the toner layer on the developing roller is brought close to or in contact with the photosensitive drum carrying the electrostatic latent image, thereby forming a toner image corresponding to the electrostatic latent image and visualizing the toner image. The developing roller is generally set to be faster than the peripheral speed of the photosensitive drum, and transmits a drive to the developing roller from a drive gear connected to a drive motor via an intermediate gear or the like.

On the other hand, the developing device is provided with stirring means for stirring the toner stored in the developing device. The stirring means supplies the consumed toner toward the developing roller or prevents the toner from forming a lump in the developing device.

As an example of the stirring means, a rod-like member such as a wire substantially parallel to the rotation axis is provided on the rotation axis at a predetermined distance around the rotation axis, and the rotation of the rotation axis causes the rod-like member to make a circular motion. The toner. The stirring means is driven by a single drive source or is obtained from a drive system for driving the developing roller.

[0005]

The above-mentioned stirring means is
If the stirring is performed too vigorously, there is a problem that contamination in the apparatus due to scattering of the toner and an adverse effect on image formation due to excessive charging of the toner. For this reason, the stirring means must be used at the lowest possible rotation speed, and when the stirring means is driven independently, a driving source different from the driving source of the developing roller is required, which complicates the apparatus and is expensive. It will be something. Further, when the drive is obtained from the drive system of the developing roller, it is necessary to greatly reduce the gear ratio of the drive system of the develop roller to reduce the stirring speed. For this reason, a large number of gears must be provided on the side of the developing device to reduce the speed, resulting in a problem that the size of the device is increased.

Further, when an intermittent gear is used to reduce the gear ratio, the gear may be damaged due to the collision of the tooth tips when the gears mesh with each other.

The present invention has been made in view of the above problems, and has as its object to provide a gear device that can reduce the gear ratio with a small number of parts and a simple configuration. In particular, it is an object of the present invention to provide a gear device of a developing device that can surely rotate a stirring device in a developing device at a low speed with a simple configuration.

[0008]

SUMMARY OF THE INVENTION To solve the above-mentioned problems, the present invention relates to a gear device having an intermittent gear to be driven and a driven gear intermittently driven by meshing with the teeth of the intermittent gear. The gear has at least two or more continuous pitch teeth, and the tooth of the intermittent gear that first contacts the tooth of the driven gear is cut into an arc shape or flat at the position of the pitch circle diameter of the intermittent gear, and It is characterized in that the driven gear is provided so that teeth thereof are sharp.

Further, at least one drive from the drive gear is provided.
In a gear device of a developing device having a stirring means for rotating a developing roller via two intermediate gears and stirring the toner stored in the developing device in response to the drive from the intermediate gear, the gear device is driven. An intermittent gear, and a driven gear intermittently driven by meshing with the teeth of the intermittent gear, the intermittent gear having at least two or more continuous pitch teeth, and The teeth of the intermittent gear that is in contact with the intermittent gear are cut in an arc shape or flat at the position of the pitch circle diameter of the intermittent gear, and the teeth of the driven gear are provided to be sharp.

[0010] Further, the stirrer is characterized in that the tip of the tooth of the intermittent gear which comes into contact with the tooth of the driven gear first is at an acute angle from the tip of one side of the tooth. Is provided near a regulating means for regulating the toner layer on the developing roller.

With such a configuration, the drive is received from a part of the intermediate gear of the drive system of the developing roller. The driven gear is provided with an intermittent gear, and the teeth of the intermittent gear intermittently transmit the drive to the driven gear. By transmitting the drive through the intermediate gear, the stirring means is driven. The rotation of the stirring means is performed at a lower speed than the rotation of the developing roller.

BEST MODE FOR CARRYING OUT THE INVENTION

A preferred embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a schematic sectional view of a developing device provided with a gear device according to the present invention. The developing device 1 includes a casing 2 that stores the toner, a developing roller 4 that develops the toner according to an electrostatic latent image formed on the photosensitive drum 3, and a stirring device that stirs the toner in the casing 2 and supplies the toner to the developing roller 4. And a regulating unit 6 for regulating the surface of the developing roller 4 into a toner layer having a predetermined thickness.

The casing 2 has an opening 7 facing the photosensitive drum 3 and extending in the axial direction of the photosensitive drum 3.
The developing roller 4 is provided so as to be rotatable facing the photosensitive drum 3 which is rotationally driven. Developing roller 4
Is provided with a permanent magnet 8 that can be fixed or rotatable inside, and a cylindrical sleeve 9 that rotates around it. In the illustrated example, the rotation direction of the sleeve 9 is set so as to rotate in the direction of arrow A and to be faster than the peripheral speed of the photosensitive drum 3 rotating in the direction of arrow B.

The stirring means 5 includes a first stirring means 5 a and a second stirring means 5 b having stirring blades 10 for supplying the toner in the developing device 1 in the direction of the developing roller 4, and a stirring means 5. A stirring rod 1 for loosening the generated toner mass
And a third stirring means 5c provided with the first stirring means 5c.

The first stirring means 5a and the second stirring means 5b have a plurality of stirring blades 10 arranged obliquely to the axial direction around the rotation shafts 12a and 12b.
With the rotation of a and 12b, the second stirring means 5b conveys the toner replenished from the toner cartridge 13 provided in the upper part of the casing 2 toward the first stirring means 5a, and the first stirring means 5a It acts to supply toner to the developing roller 4.

The regulating means 6 includes a sleeve 9 of the developing roller 4.
It is provided at a position separated from the surface by a predetermined distance in the longitudinal direction of the sleeve, and forms a toner layer having a constant thickness on the surface of the sleeve 9.

The toner is preferably a one-component magnetic toner, but may be a one-component non-magnetic toner.

FIG. 2 shows the first stirring means 5a shown in FIG.
The arrangement of a gear device for driving the second stirring means 5b, the third stirring means 5c and the developing roller 4 is shown. Gear device 14
A drive gear 17 for transmitting a drive from a drive shaft 16 of a motor 15; a developing roller 4; a first stirring unit 5a;
Intermediate gears 18a, 18b, 18c, 18d, 18 for transmitting the drive to the stirring means 5b and the third stirring means 5c.
e, 18f, 18g, 18h, an intermittent gear 19 having two or more continuous pitch teeth, a driven gear 20 meshed with and driven by a part of the intermittent gear 19, and the sleeve 9 of the developing roller 4 is rotationally driven. A gear 22 provided on the rotating shaft 21 for performing the rotation and a gear 23 provided on the first stirring means 5a
A gear 24 provided on the second stirring means 5b;
And a gear 25 provided in the stirring means 5c.

The intermediate gear 18a is provided so as to be driven and rotatable at a position where the drive of the drive gear 17 is transmitted.
b is movably provided so as to transmit the drive of the intermediate gear 18a. The intermediate gear 18c is movably provided so as to transmit the drive of the intermediate gear 18b, and transmits the drive to the gear 22 to rotate the sleeve 9 at a predetermined rotation speed.

On the other hand, the intermediate gear 18d is
And a double gear, and the intermediate gear 18d is provided so as to transmit to a gear 26 provided outside the intermittent gear 19. The intermittent gear 19 and the gear 26 form a double gear, and the driving force is applied by the intermittent gear 19 to the driven gear 2.
0. The rotation speed of the driven gear 20 is reduced to approximately 20: 1 of the rotation speed of the intermittent gear 19. The intermediate gear 18e is provided so as to transmit the drive reduced by the intermittent gear 19 and the driven gear 20, and transmits the drive to the gear 25 provided in the third agitating means 5c.
The stirring rod 11 provided inside is rotated. Intermediate gear 1
8 f is provided to transmit the drive of the gear 25.

Further, the intermediate gear 18g is provided so as to be driven by the drive of the intermediate gear 18f, and this drive drives the gear 23 provided in the first stirring means 5a to drive the stirring blade 10. Further, it is provided so as to receive the drive of the gear 23, and drives the gear 24 provided in the second stirring means 5b to drive the stirring blade 10.

FIG. 3 shows a detailed configuration of the intermittent gear 19 and the driven gear 20. The intermittent gear 19 forms a double gear with the gear 26, and rotates integrally about a shaft 29.
The intermittent gear 19 has at least two or more continuous pitch teeth 28a, 28b, and the teeth 28a of the intermittent gear 19 that first contact the teeth of the driven gear 20 are arcuate at the pitch circle diameter of the intermittent gear 19. Or it is cut flat. The pitch circle diameter is a position where the tooth side surfaces contact each other when the two gears mesh with each other, and are located at a position substantially half the tooth length. In the embodiment, the intermittent gear 1
Although nine teeth are provided, the number is not limited.

The driven gear 20 is provided such that its teeth are sharp. Intermittent gear 19 and driven gear 20
Even when the cut end of the intermittent gear 19 and the tooth tip of the driven gear 20 are in contact with each other, the side surface of the cut end of the tooth 28a or the surface that is cut in an arc shape or flat. The tooth tip of the driven gear 20 moves along any one of the surfaces to smoothly engage. This minimizes the possibility that the tips will collide with each other.

The operation of the gear device 14 according to the present invention will be described. Drive gear 1 provided on drive shaft 16 of motor 15
7 is transmitted to the intermediate gear 18a, and the drive of the intermediate gear 18a is transmitted to the intermediate gear 18b. Next, the intermediate gear 18
c is transmitted to the gear 22 to rotate the sleeve 9 at a predetermined rotation speed.

On the other hand, in response to the drive from the drive gear 17, the intermediate gear 18d, which is a double gear, drives the gear 26 to drive the intermittent gear 19, which is a double gear. Next, the drive of the intermittent gear 19 is transmitted to the driven gear 20. The rotation speed of the driven gear 20 is approximately two times the rotation speed of the intermittent gear 19.
The speed is reduced to 0: 1, and the reduced drive is applied to the intermediate gear 18e.
To the gear 2 provided on the third stirring means 5c.
5 is driven to rotate the stirring rod 11.

Next, the gear 23 provided in the first stirring means 5a is driven via the intermediate gears 18f and 18d to drive the stirring blade 10. Further, the gear 24 provided in the second stirring means 5b is driven via the intermediate gear 18h to drive the stirring blade 10.

In this embodiment, the agitating means 5 is shown as an example using a rod or a stirring blade, but may be a stirring screw. The gear device 14 is preferably made of synthetic resin such as Delrin,
The material is not limited, and may be, for example, metal. Furthermore, an example in which the gear device is used in the developing device is shown,
The present invention is not limited to this, and may be used for any device as long as the gear ratio is greatly reduced.

[0028]

According to the gear device of the present invention, the number of parts is small, and the gear ratio can be greatly reduced by a simple structure. Further, it is possible to prevent breakage due to collision between the tooth tips of the intermittent gear and the driven gear.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a developing device provided with a gear device.

FIG. 2 is a schematic view showing an example of a gear device according to the present invention.

FIG. 3 is an enlarged schematic view showing a gear device.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 developing device 2 casing 3 photosensitive drum 4 developing roller 5, 5 a, 5 b, 5 c stirring means 6 regulating means 7 opening 8 magnet 9 sleeve 10 stirring blade 11 stirring rod 12 rotating shaft 13 toner cartridge 14 gear device 15 motor 16 drive shaft 17 Drive gears 18a, 18b, 18c, 18d, 18e, 18f, 1
8g, 18h Intermediate gear 19 Intermittent gear 20 Follower gear 21 Rotary shaft 22 Gear 23 Gear 24 Gear 25 Gear 26 Gear 27 Shaft 28a, 28b Tooth

Claims (4)

[Claims] 1. A gear system comprising a driving intermittent gear and a driven gear intermittently driven by meshing with teeth of the intermittent gear, wherein the intermittent gear has at least two or more continuous pitch teeth. The teeth of the intermittent gear that first comes into contact with the teeth of the driven gear are cut so as to be arc-shaped or flat at the position of the pitch circle diameter of the intermittent gear, and the teeth of the driven gear are provided in a sharp shape. A gear device characterized in that: 2. A developing device having a stirring means for rotating a developing roller via a driving gear through at least one intermediate gear and stirring the toner stored in the developing device in response to the driving from the intermediate gear. In the gear device of the device, the gear device includes an intermittent gear to be driven, and a driven gear that meshes with teeth of the intermittent gear and is intermittently driven,
This intermittent gear has at least two or more continuous pitch teeth, and the tooth of the intermittent gear that first contacts the tooth of the driven gear is cut into an arc shape or flat at the position of the pitch circle diameter of the intermittent gear. And a gear device used in an electrophotographic apparatus, wherein the driven gear has teeth formed in a sharp shape. 3. The intermittent gear, which is in contact with the tooth of the driven gear first, is provided such that the tip of the tooth has an acute angle with respect to the tip on one side of the tooth.
A gear device used in the electrophotographic apparatus described in the above. 4. The electronic device according to claim 2, wherein the agitating means is provided near a regulating means for regulating the toner layer on the developing roller, and agitates the toner block blocked by the regulating means. Gear device used for photographic equipment.