JPH09197816A - Toner seal mechanism for bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a toner seal mechanism for a bearing which is excellent in sealing property and which is equipped with a sealing material capable of being smoothly press-fit in a bearing and having no possibility that a foreign matter is produced in the case of press-fitting. SOLUTION: One part of the inner surface side of the bearing 3 supporting a rotary shaft 2 is gouged out like a ring so as to form a ring-like space 9, and the ring-like sealing material 10 having a lip part 12 is press-contacted and fixed on the inner surface of the bearing 3 forming the space 9. The lip part 12 is allowed to abut on the rotary shaft 2. A metallic ring 4 is attached to the outer periphery side of the sealing material 10 in press-contact with the inner surface of the bearing 3 forming the space 9, and the press-fit side end face 11 of the metallic ring 4 is worked to be spherical.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner seal mechanism for a bearing of an electrophotographic apparatus.
The present invention relates to a toner seal mechanism for a bearing of a rotary shaft in a developing unit, a cleaning unit, etc.

[0002]

2. Description of the Related Art In general, a clearance of 10 to several tens of .mu.m is often provided between a rotary shaft of a developing section, a cleaning section, etc. of an electrophotographic apparatus and a bearing in order to maintain smooth rotation. However, since the toner particle size is smaller than this clearance, the toner may infiltrate into the bearing portion and may be melted and solidified due to frictional heat due to sliding, and the rotating shaft may not rotate smoothly. Further, the toner may leak from the clearance to contaminate the surroundings, and may cause trouble in operation. With the recent demand for improvement in image quality, the toner particle size tends to become smaller, so it is not easy to prevent toner leakage. As a sealing technique for solving such a problem, for example, the following are known.

As shown in FIG. 2A, a nitrile rubber (hereinafter abbreviated as "NBR") or a fluororubber (hereinafter referred to as "NBR") in which a metal ring 4a is externally mounted on a bearing 3 which supports a rotary shaft 2 of a developing device main body frame 1 A toner seal mechanism having a structure in which a seal member composed of a synthetic rubber lip seal 5a such as "FKM" is attached is known (hereinafter referred to as "conventional toner seal mechanism 1"). 2B is an enlarged view of the seal member, and FIG. 2C is a partially enlarged view of FIG. 2A.

Further, as shown in FIG. 3, a bearing 3 for supporting the rotary shaft 2 is provided with a seal member in which a metal ring 4b is embedded in a lip seal 5b made of synthetic rubber such as NBR or FKM. A toner seal mechanism is known (hereinafter referred to as "conventional toner seal mechanism 2").

[0005]

However, in the case of the seal member of FIG. 2, as shown in FIG. 5, when the metal member is press-fitted for mounting on the bearing 3, the surface of the bearing 3 is formed by the sharp corners 6 of the metal ring end surface. Since the minute convex portions 7 are scraped off and the shavings are accumulated between the seal member and the bearing, the sealing performance is deteriorated.

Further, in the case of the seal member of FIG. 3, there is no possibility that foreign matter as described with reference to FIG. 5 is generated, but this rubber-coated seal member has a large coefficient of friction with the bearing, so that the seal member smoothly enters the bearing. Cannot be charged. In addition, the rubber may be lifted up due to deformation, and some rework is required to properly mount the rubber, which increases the number of assembly steps.

If the toner seal member is mounted on the bearing by the press-fitting method, the above-mentioned problems may occur. Therefore, the sealant member of the bearing used in the developing machine may be adhered without the press-fitting method. Although the fixing method is adopted, in this case, the number of assembling steps is further increased.

The present invention has been made in view of the above problems of the prior art, and an object thereof is to smoothly press-fit into a bearing and to prevent foreign matter from being generated during press-fitting. It is an object of the present invention to provide a toner seal mechanism for a bearing, which is provided with a seal material and has a good sealing property.

[0009]

In order to solve the above-mentioned problems, the present invention is to mount a metal ring on the outer peripheral side of a ring-shaped sealing material that is in pressure contact with the inner surface of a bearing forming a ring-shaped space, and press-fit the metal ring. By processing the side end surface into a spherical shape, the ring-shaped seal material can be smoothly press-fitted into the bearing even if there are minute protrusions on the inner surface of the bearing, so shavings and other foreign matter are generated. There is no such thing.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION That is, according to the present invention, a ring-shaped sealing material having a lip portion is formed by forming a ring-shaped space by engraving a part of the inner surface side of a bearing that supports a rotary shaft in a ring shape. In a toner seal mechanism of a bearing, which is pressed against and fixed to the inner surface of a bearing forming a space, and the lip portion is brought into contact with a rotating shaft, a metal ring is formed on the outer peripheral side of a ring-shaped sealing material which is pressed against the inner surface of the bearing forming a ring-shaped space And the press-fitting side end surface of the metal ring is processed into a spherical shape.

As the material of the ring-shaped sealing material, in addition to NBR and FKM which are generally used as the sealing material, a thermoplastic elastomer can be used.

Examples of the thermoplastic elastomer include urethane type thermoplastic elastomer, polyamide type thermoplastic elastomer, polyester type thermoplastic elastomer, vinyl chloride type thermoplastic elastomer, NBR type thermoplastic elastomer, fluorine type thermoplastic elastomer and silicone type thermoplastic elastomer. , An olefin-based thermoplastic elastomer or the like.

The hardness of the ring-shaped sealing material is preferably 50 to 90 ° in Shore A type hardness. I mean,
If the hardness is less than 50 ° in Shore A type hardness, it is difficult to obtain the surface pressure required for sealing, while if the hardness is more than 90 ° in Shore A type hardness, the tightening force on the rotating shaft is high. This leads to an increase in rotation torque.

When press-fitting the ring-shaped sealing material having the above-described structure into the bearing, as shown in FIG. 4, even if there is a minute convex portion 7 on the surface of the bearing 3, the ring-shaped sealing material is formed. Since the press-fitting side end surface of the metal ring 4 mounted on the outer peripheral side is provided with the spherical processing 8, the metal ring 4 smoothly rides over the convex portion 7 and slides between the metal ring 4 and the surface of the bearing 3. No foreign matter such as shavings is generated with the contact operation.

[0015]

An embodiment will be described with reference to the drawings. In FIG. 1, the rotary shaft 2 of the frame 1 of the developing machine main body
A ring-shaped space 9 is formed by scooping in a ring shape on the inner surface side of the bearing 3 that supports the. On the inner surface of the bearing 3 in which the ring-shaped space 9 is formed, a ring-shaped sealing material 10 made of a synthetic rubber lip seal 5 having an annular metal ring 4 mounted on the outer peripheral side is pressed and fixed. Since the press-fitting side end surface 11 of the metal ring 4 is subjected to the spherical processing 8 (see FIG. 4), the press-fitting of the ring-shaped sealing material 10 into the ring-shaped space 9 will be described with reference to FIG. As described above, no foreign matter such as shavings is generated. Further, a lip portion 12 is formed on the inner peripheral surface side of the ring-shaped sealing material 10, and the lip portion 12 is in contact with the rotary shaft 2.

Thus, the ring-shaped sealing material 10 of the present invention.
According to the above, no foreign matter is generated when the toner is press-fitted into the bearing 3, and the lip portion 12 contacting the rotary shaft 2 prevents the toner 13 from entering and maintains a good sealing property.

Next, an investigation will be conducted comparing the presence or absence of damage on the bearing surface when the ring-shaped seal material of the present invention is press-fitted into the ring-shaped space in the bearing based on specific numerical values, in comparison with the ring-shaped seal material of the comparative example. Since I did, I will explain the results.

A metal ring 4 having a thickness of 0.5 mm is mounted on the outer peripheral side, and the metal ring 4 of the NBR ring-shaped sealing material 10 having an inner diameter of 6 mm and an outer diameter of 10 mm as shown in FIG. The end face 11 is spherically machined with a radius of 0.3 mm, and the press-fitting margin is 5/100 mm.
It was press-fitted into the ring-shaped space 9. This work is performed on 100 ring-shaped sealing materials of the same shape and the same material,
Then, the press-fitted ring-shaped sealing material is removed, and the bearing 3
The surface was observed, but there was no damage and no generation of foreign matter was observed.

Next, in the same manner as above, the metal ring of the ring-shaped sealing material is processed into a spherical shape from the corners of the metal ring instead of the spherical shape.
Cut off the 3 mm part into a triangular cross section (see Fig. 5),
The same press-fitting operation was performed on 100 ring-shaped sealing materials having the same shape and the same material. As a result, when observing the surface of the bearing 3 from which the press-fitted ring-shaped sealing material is removed,
Damage was found in the individual bearings, and shavings of the bearing material had adhered to the 12 bearings.

[0020]

Since the toner seal mechanism of the bearing of the present invention is constructed as described above, the following effects can be obtained. (1) The ring-shaped sealing material can be smoothly press-fitted into the ring-shaped space inside the bearing, and there is no risk of foreign matter occurring during press-fitting. (2) Since the ring-shaped sealing material is fixed by pressure welding, the number of assembly steps can be significantly reduced as compared with the conventional bonding method. (3) It is possible to secure a sufficient press-fitting margin, and since there is no gap between the bearing surface and the bearing surface, there is no toner leakage due to runout of the rotating shaft. (4) Thus, the toner seal mechanism of the bearing of the present invention can maintain good sealability for a long period of time.

[Brief description of drawings]

FIG. 1 is a side sectional view of a toner seal mechanism of a bearing of the present invention.

2 (a) is a side sectional view of a conventional toner seal mechanism 1, FIG. 2 (b) is an enlarged view of the seal member shown in FIG. 2 (a), and FIG. 2 (c) is FIG. ) Is a partially enlarged view of FIG.

FIG. 3 is a side sectional view of a conventional toner seal mechanism 2.

FIG. 4 is a diagram illustrating a state in which the ring-shaped sealing material of the present invention is press-fitted into the bearing.

FIG. 5 is a diagram illustrating a state in which a conventional sealing material is press-fitted into a bearing.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Frame 2 ... Rotating shaft 3 ... Bearing 4 ... Metal ring 5 ... Lip seal 8 ... Spherical processing 9 ... Ring-shaped space 10 ... Ring-shaped sealing material 11 ... Press-fit side end surface 12 ... Lip 13 ... Toner

Claims (1)

[Claims] 1. A ring-shaped space is formed by scooping a part of the inner surface side of a bearing that supports a rotating shaft into a ring shape, and a ring-shaped sealing material having a lip portion is pressed against the inner surface of the bearing that forms the ring-shaped space. In a toner seal mechanism of a bearing that is fixed and has the lip portion abutting on the rotating shaft, a metal ring is attached to the outer peripheral side of the ring-shaped sealing material that is in pressure contact with the inner surface of the bearing that forms the ring-shaped space, and the metal ring A toner seal mechanism for a bearing, characterized in that the press-fitting side end face of is processed into a spherical shape.