JPH10123840A - Magnetic cylinder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To miniaturize a copying machine, a facsimile device or a laser printer incorporating a magnetic cylinder in it by shortening a magnetic cylinder. SOLUTION: The cylinder is constituted so as to rotatably support a magnet roll provided projectingly with shaft parts on both side in a sleeve with a bearing 7 member incorporated in a flange member 5 for closing both sides of the sleeve and to seal the periphery of the shaft part with a mechanical seal incorporated in the flange member 5. In this case, as the bearing 7 member, a sintered oil-containing bearing 7 is used and the whole or a part of the thickness in the axial direction of the mechanical seal is coaxially incorporated in the range of the length in the axial direction of the sintered oil-containing bearing 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic cylinder incorporated in a copying machine, a facsimile, a laser printer, and the like.

[0002]

2. Description of the Related Art Magnetic cylinders are used in developing devices and cleaning devices incorporated in electrophotographic copying machines, facsimile machines and laser printers. This magnetic cylinder has a cylindrical columnar magnet 51 as shown in FIG.
Roll 5 constructed by passing shaft 52 through
3 is rotatably supported in a cylindrical sleeve 54 via flange members 55 and 56 for closing both ends of the sleeve. The flange members 55 and 56 are made of stainless steel,
It is made of a non-magnetic material such as aluminum or synthetic resin. In particular, the supporting structure of the flange member 55 on the left side in the drawing, which penetrates the shaft end 52a serving as the drive shaft, slides the shaft end 52a of the magnet roll 53 by the sintered oil-impregnated bearing 57 incorporated in the flange main body 55a. A structure in which the inner and outer spaces of the sleeve 54 are blocked by a synthetic rubber oil seal 59 incorporated in the flange member 55 so that toner and dust can be prevented from entering the sleeve 54. . In this example, the shaft end 52a of the magnet roll 53 projecting to the right side in the drawing does not penetrate the flange member 56. Therefore, the flange member 56 for rotating and supporting the shaft is not provided with an oil seal. When the pierce through the flange member 56, of course, an oil seal is also provided in this portion.
In some cases, a rolling bearing is used instead of using a sintered oil-impregnated bearing.

[0003] The sintered oil-impregnated bearing 5 is provided on the flange member 55 through which the shaft end of the magnet roll 53 passes.
7 and the oil seal 59 are press-fitted separately in the axial direction of the shaft 52. This detail is represented by the assembly diagram of FIG. 6 and the enlarged view of the main part of FIG.

[0004]

However, in such a flange member, the dimensional accuracy of the sintered oil-impregnated bearing 57 (hereinafter, referred to as the bearing 57) and the oil seal 59 with respect to the end face of the flange member after press-fitting is improved. A wall having a thickness t of at least 0.5 mm, preferably 1 mm or more, is required between the bearing 57 and the oil seal 59 in order to prevent it from coming out or coming off. And as described above, as long as the wall exists between the bearing 57 and the oil seal 59,
The axial thickness of the flange member 55 is the axial length of the bearing + the axial thickness of the oil seal + the axial thickness of the wall,
This was an obstacle to shortening the magnetic cylinder.
The wall thickness is independent of the length of the magnet roll,
Even if it is necessary to lengthen the magnet roll 53 in the sleeve to widen the image area, a wall is necessary, so in such a case, the magnetic cylinder is further enlarged, and a copier, a facsimile or a laser incorporating the magnetic cylinder is used. This is an obstacle to downsizing the printer. The present invention has been made in view of such a situation, and by reducing the axial thickness of the flange member, the magnetic cylinder is shortened, and thus the copier, facsimile and laser printer incorporating the magnetic cylinder are downsized. It is something that does not matter.

[0005]

In order to solve the above-mentioned problems, the present invention uses a sintered oil-impregnated bearing as a bearing member, and has the entire mechanical thickness of the mechanical seal within the axial length range of the sintered oil-impregnated bearing. Alternatively, it is characterized in that a part is incorporated coaxially.

Instead of incorporating the bearing member in the flange member, the outer shape of the sintered oil-impregnated bearing may be formed into a shape corresponding to the flange member, and the sintered oil-impregnated bearing may also serve as the flange member.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will now be described with reference to the illustrated embodiments. FIG. 1 is a sectional explanatory view of a flange member incorporated in a magnetic cylinder of the present invention, and FIG. 2 shows an assembling procedure of the flange member. The flange member 5 has a configuration in which the oil seal 9 is coaxially incorporated within the axial length range of the sintered oil-impregnated bearing 7. In the illustrated example, the entire thickness of the oil seal 9 in the axial direction is incorporated within the axial length range of the sintered oil-impregnated bearing 7, but only a part of the axial thickness of the oil seal 9 may be incorporated. . For example, as shown in FIG. 2, the assembly of the flange member 5 is performed by preparing a sintered oil-impregnated bearing 7 in which an oil seal 9 is press-fitted in advance, and press-fitting the oil seal 9 into the flange main body 5a. An adhesive is not usually required on the contact surface between the flange main body 5a and the sintered oil-impregnated bearing 7, but may be interposed if necessary. Thus, the oil seal 9
Is incorporated in the axial length range of the sintered oil-impregnated bearing 7 so that the oil seal 9 does not need to have a “wall” between the sintered oil-impregnated bearing 7 and the oil seal 9, so that the oil seal 9 can enter and exit the flange end face. It is possible to shorten the axial length of the flange main body 5a while setting it with high accuracy.
The sintered oil-impregnated bearing 7 is excellent in dimensional accuracy because it is compression-molded, and the axial position of the magnetic cylinder is accurately determined only by mounting the oil seal 9 at a predetermined position of the sintered oil-impregnated bearing 7. The space for press-fitting the mechanical seal 9 into the sintered oil-impregnated bearing 7 can be easily manufactured by devising a mold for manufacturing the sintered oil-impregnated bearing 7.

As the metal powder to be used as the material of the sintered oil-impregnated bearing 7, known powders can be appropriately used, for example, Cu—Sn—C
System, Cu-Sn-Pb-C system or Fe-Cu-C system can be used. Also, composite materials of metal powder and ceramic powder,
A composite material of a metal powder and a synthetic resin powder may be used as needed.

The oil seal 9 is made of synthetic rubber. It is also possible to use another mechanical seal in place of the oil seal, and a mechanical seal made of carbon or a synthetic resin such as tetrafluoroethylene resin having excellent abrasion resistance and excellent lubricity may be used. .

FIG. 3 shows a second embodiment of the present invention, in which the oil seal 9 exerts a retaining effect on the end face opposite to the side into which the oil seal 9 is press-fitted, and the sintered oil-impregnated bearing 7 "itself comes into and out of the flange end face. This is a case where a flange 11 which is also a reference position of the dimension is provided, and an annular step 12 is provided on the side of the flange main body 5a 'that receives the oil seal 9.
Since the sintered oil-impregnated bearing 7 ′ is compression molded, it is difficult to form a complicated shape, but it is easy if the flange 11 is formed.

FIG. 4 shows a third embodiment of the present invention, in which the outer shape of the sintered oil-impregnated bearing 7 "is made substantially the same as the flange main body or the shape corresponding to the flange main body. "This is the case where the function of the flange body itself is also provided. Since the molding of the sintered oil-impregnated bearing 7 "is compression-molded, dimensional accuracy that can be closely fitted to the sleeve can be realized relatively easily. In this case, the oil-impregnated sintered oil-impregnated bearing having the oil seal incorporated therein is pressed into the flange body. No labor is required, and assembly man-hours can be reduced.

[0012]

According to the magnetic cylinder of the present invention, a sintered oil-impregnated bearing is used as a bearing member, and all or a part of the axial thickness of the mechanical seal is coaxial within the axial length range of the sintered oil-impregnated bearing. , The axial length of the flange member can be reduced, and the magnetic cylinder can be shortened. Therefore, the size of a device incorporating a magnetic cylinder such as a copying machine, a facsimile, and a laser printer can be reduced. Also, the outer shape of the sintered oil-impregnated bearing
When the outer shape of the flange body is made to match the outer shape of the flange body, or the shape equivalent to the outer shape of the flange body, and the sintered oil-impregnated bearing itself also has the function of the flange, the number of assembly steps is reduced in addition to the downsizing of the magnetic cylinder. Can be reduced.

[Brief description of the drawings]

FIG. 1 is an explanatory sectional view of a flange member used for a magnetic cylinder according to a first embodiment of the present invention.

FIG. 2 is an explanatory view showing an assembling procedure of the flange member of the embodiment.

FIG. 3 is an explanatory sectional view of a flange member used for a magnetic cylinder according to a second embodiment of the present invention.

FIG. 4 is an explanatory sectional view of a flange member used for a magnetic cylinder according to a third embodiment of the present invention.

FIG. 5 is a sectional view showing the structure of a conventional magnetic cylinder.

FIG. 6 is an explanatory view showing an assembling procedure of a flange member used for a conventional magnetic cylinder.

FIG. 7 is an explanatory sectional view of the flange member.

[Explanation of symbols]

Reference Signs List 5 flange member 5a flange body 7, 7 ', 7 "sintered oil-impregnated bearing 9 oil seal 11 flange 12 annular step 51 columnar magnet 52 shaft 52a shaft end 52b shaft end 53 magnet roll 54 sleeve 55 flange member 56 flange member 57 Sintered oil-impregnated bearing 59 Oil seal

Claims (2)

[Claims] 1. A magnet roll having shaft portions projecting from both ends thereof is rotatably supported in a sleeve by a bearing member incorporated in a flange member for closing both ends of the sleeve, and the shaft is formed by a mechanical seal incorporated in the flange member. In a magnetic cylinder having a hermetically sealed part, a sintered oil-impregnated bearing is used as a bearing member, and all or part of the axial thickness of the mechanical seal is coaxial within the axial length of the sintered oil-impregnated bearing. Magnetic cylinder characterized by being incorporated. 2. The sintered oil-impregnated bearing has an outer shape corresponding to the flange member, instead of incorporating the bearing member into the flange member, and the sintered oil-impregnated bearing also serves as the flange member. Magnetic cylinder.