JPH0128516Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a magnet roll used in electrophotography, facsimile receivers, etc.

Conventional Structure and Problems Generally, as shown in FIG. 1, this magnet roll consists of a cylindrical non-magnetic sleeve 1 and a rolled magnet 2 inside the non-magnetic sleeve 1 having a plurality of magnetic poles on its surface. By rotating them relative to each other, the toner is attracted and conveyed onto the non-magnetic sleeve 1 using magnetic means, and the toner is transferred to the electrostatic latent image formed on the surface of the photoreceptor, thereby making it visible. Used in magnetic brush development.

In order to relatively rotate the non-magnetic sleeve 1 and the rolled magnet 2 within this sleeve 1, the conventional magnet roll has bearings at both ends of the non-magnetic sleeve 1, and the non-magnetic sleeve 1 is rotated from both ends. Flange 3 that prevents foreign matter from entering the interior and holds the bearing
a, 3b, and bearings 4a, 4b for smooth rotation, and the shaft 5, which serves as a magnet fixing shaft for regulating the rotation or fixation of the rolled magnet 2, is attached to the outside of at least one flange 3b. A minimum clearance 6 was provided to prevent an increase in rotational load due to contact between the outer periphery of the shaft 5 and the flange 3b. When assembling this magnet roll, generally the non-magnetic sleeve 1 and the flange 3b are fixed with an adhesive 7 as shown in FIG. When the flange 3b is fixed, the inside of the non-magnetic sleeve 1 is sealed, so the air inside the non-magnetic sleeve 1, which is compressed during assembly, passes through the flange bonding part and flows to the outside as shown in 8. At this time, the adhesive 7 applied to the adhesive part with the flange 3b is pushed out by the air flow, so that the adhesive 7 applied to the adhesive part of the fitting part, that is, the adhesive part between the non-magnetic sleeve 1 and the flange 3b There was a drawback that the required amount of adhesive 7 did not remain in the gap, and the bonding force could not be maintained reliably. Therefore, when the developing device cannot withstand the rotational load when the developing device is driven, and the connection between the non-magnetic sleeve 1 and the flange 3b is broken, toner transport becomes immediately impossible.
This led to a serious defect in that it could not be developed.

In addition, the adhesive 7 applied to the flange 3b is applied to the flange 3b at a pressure higher than the air pressure inside the non-magnetic sleeve 1.
When they are fixed together, the compressed air is held inside during assembly, so it is necessary to hold the fitted state with a force greater than the air pressure until the adhesive 7 hardens, which complicates the assembly process and requires a lot of effort. It will take a long time.

The above drawback is that when a sintered oil-impregnated bearing is used as a bearing, an oil film is formed between the shaft 5 and the bearing 4b, and the inside of the non-magnetic sleeve 1 becomes more completely sealed, so this tendency is noticeable. However, when other rolling bearings, bearing bushes, etc. are used, the fit between the shaft 5 and the bearing 4b varies.

Purpose of the Invention In view of the above drawbacks, the present invention provides a magnetic roll for magnetic brush development that is easy to assemble.

Structure of the Invention In order to achieve the above object, the present invention has a structure in which air circulation holes are provided in the bearing portion.

Since the compressed air inside the non-magnetic sleeve is not released from the bonded area between the non-magnetic sleeve and flange, the adhesive applied to the bonded area between the non-magnetic sleeve and flange is easy to handle, making assembly extremely easy. Become.

DESCRIPTION OF EMBODIMENTS Details of a magnetic brush developing magnet roll in an embodiment of the present invention will be described below with reference to the drawings. Third
The figure is a perspective view of a bearing used in a magnet roll for magnetic brush development according to an embodiment of the present invention, and FIG. It is a diagram.

As shown in FIG. 3, one end surface 9 of this bearing 9
A continuous groove 12 is provided between the groove a and the peripheral surface 9b'.
Therefore, when a magnet roll for magnetic brush development is assembled using this bearing 9, the compressed air inside the non-magnetic sleeve 10 is released by fitting the flange 11 to the non-magnetic sleeve 10 as shown in FIG. trying to go outside. However, since the bearing 9 is provided with a continuous cut groove 12 that bends once or more on a part of the outer periphery and a part of the side surface, the compressed air does not pass through the adhesive part 13, and the compressed air passes through the cut groove 12, which has a small flow load.
and escapes to the outside of the magnetic brush developing magnet roll using the shaft 15 of the magnet roll 14 pulled out of the flange 11 and the gap 16 between the flange 11. For this reason, the adhesive 13 applied to the adhesive portion remains securely in the gap after the non-magnetic sleeve 10 and flange 11 are fitted, and the bonding force is maintained over the entire area of the adhesive portion. Note that the groove machining of the bearing 9 can be performed at the same time as the bearing is molded, so the bearing machining cost is the same as that of a general-purpose product.

FIG. 5 is a perspective view of a flange explaining another embodiment of the present invention. Flange 18 as shown
A groove 17 connected to the outside of the flange 18 is provided in the bearing fitting portion of the flange 18, and the same effect as that of the above embodiment can be obtained.

Note that in both of the above two embodiments, the cut groove is 1
Although this is the case, when a plurality of grooves are provided on both the bearing and the flange, the same effect can be obtained and the processing balance can be improved. Further, the cut grooves can also be provided on the inner periphery of the bearing.

Effects of the invention As described above, since there is no compressed air inside the sleeve of the magnet roll that uses the bearing and flange of the invention, assembly man-hours are reduced, it can be manufactured at low cost, and it is firmly assembled. It has the following advantages and is of great practical industrial value.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of a conventional magnetic brush developing magnet roll, Fig. 2 is a sectional view of essential parts of the same roll showing its assembled state, and Fig. 3 is a magnetic brush developing roller according to an embodiment of the present invention. A perspective view of a bearing used in a magnet roll, FIG. 4 is a cross-sectional view of a main part of the roll in an assembled state, and FIG. 5 is a perspective view of a flange used in a magnet roll for magnetic brush development in another embodiment of the present invention. It is. 9...Bearing, 10...Nonmagnetic sleeve, 11,
18...flange, 12, 17...cut groove, 13...
...adhesive, 14...roll magnet, 15...shaft.

Claims (1)

[Scope of utility model registration request] A cylindrical non-magnetic sleeve, a flange fixed with adhesive so as to close both ends of the non-magnetic sleeve, and a bearing rotatably attached to the flange inside the non-magnetic sleeve. A magnet roll for magnetic brush development, comprising a roll-shaped magnet, and the flange or bearing is provided with a groove or a through hole connecting the inside and outside of the non-magnetic sleeve.