JP4231135B2 - Rotating body seal structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sealing structure for a rotating body that comes into contact with the outer peripheral surface of the rotating body and performs sealing in the rotation axis direction.
[0002]
[Prior art]
Conventionally, a rotating shaft has been widely used as an element of various machines. The rotating shaft is generally rotatably supported at an end portion in the axial direction. The support portion of the rotating shaft has a sealing structure that not only supports the rotating shaft so as to be rotatable, but also prevents leakage of the contents and the like to the outside and entry of foreign matter from the outside. There are many cases. Various types of seal structures are used depending on the necessity and various conditions.
[0003]
FIG. 6 schematically shows a seal structure near the shaft end of the developing roller 1 used for dry development of the electrophotographic apparatus. The developing roller 1 is provided near the lower end of the developing unit 2 and supplies toner 4 as a developer to the electrostatic latent image formed on the surface of the photosensitive drum 3 to visualize the electrostatic latent image. It has the function to do. The toner 4 is in the form of fine particles and adheres to the surface of the developing roller 1 and is supplied to the photosensitive drum 3 side. However, the toner 4 moves outward along the axial direction of the developing roller 1, and is external to the developing unit 2. There is a risk of leakage. Therefore, the developing unit 2 is provided with a seal portion 5 in order to prevent the toner 4 from leaking outward in the axial direction of the developing roller 1.
[0004]
The seal portion 5 prevents the minute toner 4 adhering to the surface of the developing roller 1 from leaking outward in the axial direction as the developing roller 1 rotates. If sealing is performed with the seal portion 5 being in close contact with the surface of the developing roller 1, it should be possible to reliably prevent the toner 4 from leaking. However, when the seal area is increased, the load when the developing roller 1 is driven by the frictional force is increased, and the motor for driving the developing roller 1 must be enlarged. For this reason, in the technology that forms the basis of the present invention, the seal member 7 is attached to the surface of the sheet material 6 provided around the developing roller 1 as the seal portion 5, and the seal member 7 is not applied to the entire seal portion 5. A structure in which sealing is performed while partially contacting the outer peripheral surface of the developing roller 1 is considered. A sponge-like material is disposed as the pressure applying member 8 on the back side of the sheet material 6 so that the surface of the seal member 7 is surely in contact with the outer peripheral surface of the developing roller 1.
[0005]
FIG. 7 shows a state in which the seal portion 5 shown in FIG. 6 is viewed from the front side. The seal portion 5 is provided so as to partially contact the outer peripheral surface in the vicinity of both ends of the developing roller 1 in the direction of the axis 1a. The surface of the seal member 7 indicated by hatching is in contact with the outer peripheral surface of the developing roller 1, and the toner 4 shown in FIG. The toner 4 is prevented from flowing and leaking outward in the direction of the axis 1a. The contact area at the seal portion 5 is the area indicated by hatching, and is a small area from the entire surface of the sheet material 6, so the load on the rotational driving of the developing roller 1 is reduced, and the drive motor and the like The required output is reduced and the size can be reduced.
[0006]
Since the developing roller 1 faces the photosensitive drum 3, it is difficult to seal the entire circumference of the end portion in a cylindrical shape, and the semicircular seal portion 5 must be sealed in the axial direction. Conventionally, a felt-like seal member is provided on the back side of the end of the developing roller 1 to seal the toner 4.
[0007]
[Problems to be solved by the invention]
The problem with the prior art seal that uses a felt that has a semicircular curved seal at the end of the developing roller is difficult to align with a regulating blade that regulates the amount of toner adhering to the surface of the developing roller. In addition, the stickiness of the end may deteriorate due to the protrusion of the felt. In the seal part 5 formed by laminating the seal member 7 as shown in FIG. 7 on the surface of the sheet material 6, man-hours for laminating the seal member 7 on the surface of the sheet material 6 are required, which increases the manufacturing cost. In addition, it is difficult to ensure accuracy in the laminating operation, and the shapes that can be realized are limited.
[0008]
An object of the present invention is to provide a seal structure for a rotating body that can manufacture a seal portion similar to the seal portion 5 formed by the seal member 7 as shown in FIG. 7 at a lower cost and with higher accuracy. Is to provide.
[0009]
[Means for Solving the Problems]
The present invention is, while contacting with the axial direction of the end portion on the outer peripheral surface of the rotating body that rotates about the axis, the rotation for deposits on the outer peripheral surface of the rotating body is restricted from flowing out to the outside in the axial direction A body seal structure,
A sheet material provided so as to cover the restriction portion of the outer peripheral surface of the rotating body;
On the surface of the side that faces an outer circumferential surface of said rotary member of said sheet material is formed by printing, along the moving direction of the outer peripheral surface of the rotating body, seen including a convex pattern in contact with the outer peripheral surface ,
The convex pattern includes a portion formed to extend in the moving direction, and an inclined portion that contacts the outer peripheral surface while inclining inward in the axial direction along the moving direction of the outer peripheral surface of the rotating body. It is the sealing structure of the rotary body characterized by having .
[0010]
According to the present invention, the sheet material is provided so as to cover the restriction portion on the outer peripheral surface of the rotating body that rotates around the axis. A convex pattern is formed by printing on the surface of the sheet material opposite to the outer peripheral surface of the rotating body. The convex pattern is formed on the outer peripheral surface of the rotating body by printing in a shape that is inclined inward in the axial direction along the moving direction of the outer peripheral surface during rotation. Since the convex pattern is formed by printing, it can be accurately formed with a uniform thickness on the surface of the sheet material. Since the convex pattern is inclined inward in the axial direction along the direction in which the outer peripheral surface of the rotating body moves during rotation, the entire surface of the sheet material is prevented from contacting the outer peripheral surface of the rotating body. An increase in rotational load can be avoided. Since the convex pattern is formed by printing, it can be formed at a relatively low cost and a uniform thickness for efficient sealing. The convex pattern includes a portion formed to extend in the moving direction of the rotating body, and an inclined portion that contacts the outer peripheral surface while inclining inward in the axial direction along the moving direction of the outer peripheral surface of the rotating body. Therefore, it is possible to more reliably prevent the toner from leaking outward in the axial direction.
[0011]
In the present invention, the deposit is a toner used for dry development of an electrophotographic apparatus,
The rotating body is a developing roller, and the convex pattern has a thickness of 10 μm to 150 μm.
[0012]
According to the present invention, the developing process of the toner that adheres to the outer peripheral surface of the developing roller and makes the electrostatic latent image appear is performed. The toner is fine particles and adheres to the surface of the developing roller, and easily leaks outward in the axial direction. Since only the surface of the inclined pattern contacts the surface of the developing roller for sealing, it is possible to urge the convex pattern to be pressed against the surface side of the developing roller with a strong force from the back side of the sheet material. Sealing can be performed reliably. Since the area of the portion where the surface of the convex pattern is in contact with the outer surface of the developing roller is small, the increase in the load for rotating the developing roller is reduced, and the electrophotographic apparatus can be configured in a small size.
[0013]
In the present invention, the convex pattern has a curvature radius of an edge shape of the inclined portion that is equal to or less than the thickness, and is formed in an area range of 10% to 75% on the surface of the sheet material.
[0014]
According to the present invention, the convex pattern formed on the surface of the sheet material by printing has an edge portion with a radius of curvature equal to or less than the thickness and adheres to the surface of the developing roller at a portion rising from the surface of the sheet material. The toner can be reliably regulated. Since the convex pattern is formed on the surface of the sheet material in an area range of 10% to 75%, the contact area is reduced, the contact pressure per unit area is increased, and the toner in the axial direction is at the contact portion. It can be surely sealed so as not to leak outward.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a state in which a rotating body seal structure according to an embodiment of the present invention is applied to a seal performed at an end portion in the direction of the axis 12 of a developing roller 11. FIG. 1A shows a configuration viewed from the front side, and FIG. 1B shows a cross-sectional configuration viewed from the side. The developing roller 11 is rotationally driven around the axis 12 in the direction of the arrow 12a shown in FIG. The developing roller 11 is mounted in the vicinity of the lower end of the developing unit equivalent to the developing unit 2 as shown in FIG. 6, and one side surface faces the photosensitive drum equivalent to the photosensitive drum 3 in FIG. When the developing roller 11 is rotationally driven in the direction of the arrow 12a, the toner adhering to the surface of the developing roller 11 moves in the circumferential direction 13 shown in FIG. In order to restrict the toner to move in the toner regulation direction 14, that is, inward of the axis 12, a seal portion 15 is provided. The seal portion 15 is manufactured by a printing method so that the seal member 17 is formed on the surface of the sheet material 16. As shown by hatching, an elastic body such as a sponge-like rubber material that is the pressure applying member 18 is provided on the back side of the sheet material 16 so that the surface of the seal member 17 is in close contact with the outer peripheral surface of the developing roller 11. Is placed.
[0016]
In the seal portion 15 of this embodiment, the sheet materials 16a and 16b are disposed at both ends in the direction of the axis 12 of the developing roller 11, and the sheet materials 16a and 16b at both ends are connected by a sheet material 16c parallel to the direction of the axis 12. Are integrally formed. Since the sheet materials 16a and 16b on both ends of the axis 12 need to be bent in a semicircular shape along the outer peripheral surface of the developing roller 11, the sheet materials 16a and 16b on both ends and the connecting sheet material 16c Are formed with cuts 16d and 16e, respectively. As described above, the whole of the sheet materials 16a and 16b on both ends, the connecting sheet material 16c, and the cuts 16d and 16e will be collectively referred to as reference numeral “16”. The sheet material 16c of the connecting portion on the inner side with respect to the axis line 12 from the notches 16d and 16e is in a flat state and is fixed to the container of the developing unit. On the sheet materials 16a and 16b on both sides, seal members 17a and 17b shown by hatching are formed as a convex pattern by printing. Hereinafter, the seal members 17a and 17b are collectively referred to as a reference numeral “17”.
[0017]
FIG. 2 shows a partial cross-sectional configuration of the seal portion 15 shown in FIG. The developing roller 11 is provided in the vicinity of the lower end of the container 21 of the developing unit 20, and the sheet material 16 and the pressure applying member 18 that seal the seal portion 15 at the shaft end are held by holding portions 22 and 23 formed in the container 21. Then, sealing is performed while the seal member 17 is in contact with the outer peripheral surface of the developing roller 11. Toner is stored in the container 21 of the developing unit 20, adheres to the surface of the developing roller 11, and develops the photosensitive drum or the like that faces the opening 24 side of the container 21. The diameter of the developing roller 11 is several mm to several tens mm, and the length in the direction of the axis 12 is several tens cm.
[0018]
FIG. 3 shows the shape of the seal member 17 formed on the surface of the sheet material 16 by printing. FIG. 3A shows a planar shape, and FIG. 3B shows an enlarged cross-sectional shape viewed from the section line III-III in FIG. On the surface of the sheet material 16, the seal member 17 has an angle θ of 90 ° <θ <180 ° so that the toner relatively moving along the circumferential direction 13 is regulated toward the toner regulation direction 14. It is formed so as to be inclined in the range. The width of the seal member 17 in the direction perpendicular to the toner regulating direction 14 is several mm.
[0019]
As shown in FIG. 3B, the seal member 17 formed on the surface of the sheet material 16 is formed to have a thickness t2 with respect to the thickness t1 of the sheet material 16. The sheet material 16 is made of, for example, polyethylene terephthalate (PET), and the thickness t1 is about 0.1 mm. The seal member 17 is formed, for example, by using an ultraviolet (UV) curable resin ink, attached to the surface of the sheet material 16 by a screen printing method, and curing by ultraviolet irradiation. If the coating is performed twice by silk screen printing, the seal member 17 can be formed with a thickness t2 of 150 μm at the maximum. It is preferable that the corner portion 17r of the seal member 17 has a clear edge as much as possible so that the radius of curvature is equal to or less than the thickness t2. When the radius of curvature of the corner portion 17r is large, the ratio of the portion of the width W of the seal member 17 that substantially contacts the outer peripheral surface of the developing roller 11 is reduced, and the toner is regulated inward in the direction of the axis 12. Will be weakened.
[0020]
The seal part 15 of this embodiment is manufactured through the following processes.
(1) A convex pattern corresponding to the seal member 17 is formed on the raw material of the sheet material 16 by ultraviolet curable ink by printing using a silk screen.
(2) The ink adhered on the surface of the sheet material 16 as a convex pattern is cured.
(3) A shape as shown in FIG. 1A is punched from the sheet material 16.
[0021]
In the manufacturing process of the seal portion 15 of the present embodiment, as shown in (1) to (3), the state in which the seal members 17a and 17b are formed on the sheet materials 16a and 16b on both sides of FIG. They can be integrally formed in a form connected by the sheet material 16c of the connecting portion. And since it is not necessary to perform the sticking operation | work of the sealing member 17, etc., it can manufacture efficiently and at low cost. Since the pattern formation of the seal member 17 and the cutting of the sheet material 16 can be accurately performed using a mold, the seal portion 15 having excellent dimensional accuracy can be easily obtained.
[0022]
FIG. 4 shows an example of a seal member 17 that can be used as the seal portion 15 of the present invention. 4A shows a seal member 17 used in the seal portion 15 of the embodiment of FIG. 1, and FIGS. 4B, 4C, and 4D show seal members 27, 28, and 29 having other shapes. An example of In the sealing member 27 shown in FIG. 4 (b), the same as the sealing member 17 in FIG. 2 (b), which is a portion formed so as to extend in the circumferential direction at the side end in the axial direction of the sheet material 16. It is formed by combining the inclined portion 27b. Since the circumferential portion 27a is provided, it is possible to more reliably prevent the toner from leaking outward in the axial direction. FIG. 4C shows the seal member 28 in which a plurality of inclined portions 28b are provided with respect to the portion 28a formed in the circumferential direction. Since a plurality of the inclined portions 28b are provided, the toner can be more reliably regulated inward in the axial direction. FIG. 4D shows the seal member 29 in which only a plurality of inclined portions are formed. With the plurality of inclined portions, the toner can be reliably regulated inward in the axial direction.
[0023]
FIG. 5 shows a state where sealing is performed over the entire circumference of the rotary shaft 31 at the shaft end portion of a general rotary shaft 31 as a seal portion 30 according to still another embodiment of the present invention. The entire circumference of the rotating shaft 31 is covered with a sheet material 32, and a gap is provided between the inner peripheral surface of the sheet material 32 and the outer peripheral surface of the rotating shaft 31. A plurality of seal members 33 formed by printing are provided on the inner peripheral surface of the sheet material 32, and sealing is performed in a state where the surface of the seal member 33 is in contact with the outer peripheral surface of the rotating shaft 31. Since the contact area of the seal member 33 is smaller than that of the entire inner peripheral surface of the sheet material 32, it is possible to perform sealing by reliable contact with a small load on the rotation of the rotary shaft 31.
[0024]
【The invention's effect】
As described above, according to the present invention, a convex pattern is formed by printing on the surface of the sheet material, the thickness of the portion in contact with the outer peripheral surface of the rotating body is made uniform, and the deposit on the outer peripheral surface of the rotating body is the axis line. It is possible to surely regulate so as not to flow outward in the direction. Since the convex pattern is formed by printing, cheaper and more reliable sealing can be performed as compared with a method in which a sealing member having a certain thickness is attached to the surface of the sheet material. The convex pattern includes a portion formed to extend in the moving direction of the rotating body, and an inclined portion that contacts the outer peripheral surface while inclining inward in the axial direction along the moving direction of the outer peripheral surface of the rotating body. Therefore, it is possible to more reliably prevent the toner from leaking outward in the axial direction.
[0025]
According to the present invention, the seal at the end in the axial direction of the developing roller that supplies toner used for dry development of the electrophotographic apparatus to the photosensitive member is printed by printing a convex pattern having a thickness of 10 μm to 150 μm. Formed on the surface of the sheet material, it is possible to reliably prevent the toner from flowing out in the axial direction.
[0026]
Further, according to the present invention, the curvature radius of the edge portion of the convex pattern formed by printing on the surface of the sheet material is equal to or less than the thickness, and is formed in the area range of 10% to 75% on the surface of the sheet material. It is possible to surely prevent outflow on the outer peripheral surface of the developing roller while suppressing an increase in load for driving the developing roller.
[Brief description of the drawings]
FIG. 1 is a simplified front view and side sectional view showing a schematic configuration of an embodiment of the present invention.
2 is a partial cross-sectional side view of a developing unit 20 including the developing roller 11 of FIG.
FIGS. 3A and 3B are a plan view and an enlarged cross-sectional view showing a detailed configuration of the seal portion 15 of FIG.
4 is a simplified plan view showing the seal member 17 of the embodiment of FIG. 1 in comparison with the seal members 27, 28, 29 of another embodiment of the present invention. FIG.
FIG. 5 is a partial perspective view showing a configuration of a seal portion 30 according to still another embodiment of the present invention.
FIG. 6 is a partial side cross-sectional view illustrating a configuration of a seal portion of a conventional developing roller.
FIG. 7 is a simplified front view of the seal portion 5 of FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 11 Developing roller 12 Axis 13 Circumferential direction 14 Toner regulation direction 15, 30 Seal part 16 Sheet material 17, 27, 28, 29 Seal member 17r Corner part 18 Pressure applying member 20 Developing unit 31 Rotating shaft

Claims (3)

While contacting with the outer peripheral surface of the rotary body rotating around the axis in the axial direction of the end portion, the sealing structure of the rotary body for attachment of the outer peripheral surface of the rotating body is restricted from flowing out to the outside in the axial direction Because
A sheet material provided so as to cover the restriction portion of the outer peripheral surface of the rotating body;
On the surface of the side that faces an outer circumferential surface of said rotary member of said sheet material is formed by printing, along the moving direction of the outer peripheral surface of the rotating body, seen including a convex pattern in contact with the outer peripheral surface ,
The convex pattern includes a portion formed to extend in the moving direction, and an inclined portion that contacts the outer peripheral surface while inclining inward in the axial direction along the moving direction of the outer peripheral surface of the rotating body. seal structure of the rotating body and having a. The deposit is a toner used for dry development of an electrophotographic apparatus,
2. The seal structure for a rotating body according to claim 1, wherein the rotating body is a developing roller, and the convex pattern has a thickness of 10 [mu] m to 150 [mu] m.   3. The convex pattern according to claim 2, wherein a curvature radius of an edge shape of the inclined portion is equal to or less than the thickness, and is formed in an area range of 10% to 75% on the surface of the sheet material. Rotating body seal structure.

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