JPH0231765Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a magnet roll, and particularly to a magnet roll used for conveying magnetic developer in image forming apparatuses such as electrophotographic copying machines, facsimile machines, and printers. It is.

As a means for transporting developer in magnetic brush development, magnetic brush cleaning, etc., a magnet is used, which has a cylindrical sleeve made of a non-magnetic material and a permanent magnet having a plurality of magnetic poles on the surface that rotates relative to each other. Nettrol is used.

First, the installation of a conventional magnet roll of this type will be explained based on FIG.

Here, FIG. 1 is a longitudinal sectional front view of a conventional magnet roll.

In the figure, 1 is a permanent magnet having a plurality of magnetic poles on its surface, 2 is a support shaft of the permanent magnet 1, 3 and 3' are side plates, and 4 is a stopper member integrally fixed to the side plate 3. , the support shaft 2 is inserted into the stopper member 4 and fixed to the stopper member 4 by a bolt 5 and a washer 6. Reference numeral 7 denotes a sleeve made of a non-magnetic material, and 8, 8' denote flange members to which the sleeve 7 is attached, and are rotatably supported on the support shaft 2 via bearings 9, 9'. 10 is a flange member 8
This is an oil sheet fitted on the end face of the bearing 9 to prevent developer from entering the bearing 9. The shaft portion 11 of the flange member 8' is supported by the side plate 3' via a bearing 9''. Reference numeral 10' is an oil seal for preventing developer from entering the bearing 9''.

As mentioned above, the conventional magnet roll has a structure in which the oil seal 10 is fitted to the end face of the flange member 8 in order to prevent developer from entering the bearing 9, resulting in a complicated structure and increased manufacturing costs. It had the disadvantage of being expensive.

This invention eliminates these drawbacks,
The object of the present invention is to provide a magnet roll that has a simple structure and prevents developer from entering the bearing.

The present invention provides a magnet roll in which flange members fixed to both ends of a cylindrical sleeve made of a non-magnetic material are rotatably provided on a support shaft of a permanent magnet via a bearing, in which at least one of the flange members is provided. The magnet roll is made of an organic polymer, and has a narrow protrusion formed on the inner circumferential surface of the flange member to abut on the outer circumferential surface of the support shaft of the permanent magnet.

Embodiments of the present invention will be described below based on the drawings.

FIG. 2 is a longitudinal sectional front view of a main part of a magnet roll according to an embodiment of the present invention.

In this figure, parts equivalent to those in FIG. 1 are designated by the same reference numerals.
8a is a flange member made of plastic;
Reference numeral 12 denotes a narrow protrusion formed on the inner circumferential surface of the flange member 8a so as to abut on the outer circumferential surface of the support shaft 2 of the permanent magnet 1. This protruding portion 12 is formed when the flange member 8a is injection molded from a plastic material, and by appropriately setting the inner diameter dimension of the protruding portion 12, it is possible to achieve a sealing effect against intrusion of developer equivalent to that of an oil seal. Hatasu.

For example, the dimension of support shaft 2 is 8φmm (+0 to -
0.025), the inner diameter of the protrusion 11 should be 8φmm (-
0.025 to -0.050), a sufficient sealing effect can be obtained.

As explained above, in the magnet roll according to this embodiment, when the flange member 8a is injection molded on the inner peripheral surface of the flange member 8a to which the sleeve 7 is fixed, the outer peripheral surface of the support shaft 2 of the permanent magnet 1 is A narrow protrusion 12 is formed that comes into contact with the.
The protrusion 12 can be easily configured and can sufficiently prevent developer from entering the bearing 9.

In addition, in the above embodiment, the flange member 8
Although the bearing 9 is molded from plastic, the bearing 9 can be omitted if it is molded from a self-lubricating material such as Delrin.

As described above, the present invention enables a magnet roll that can prevent developer from entering the bearing with a simple structure, and can be said to be an invention with excellent practical effects.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional front view of a conventional magnet roll, and FIG. 2 is a longitudinal sectional front view of essential parts of a magnet roll according to an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Permanent magnet, 2... Support shaft, 7... Sleeve, 8a... Flange member, 9... Bearing, 12...
...protrusion.

Claims (1)

[Scope of utility model registration request] In a magnet roll, in which flange members fixed to both ends of a cylindrical sleeve made of a non-magnetic material are rotatably provided on a support shaft of a permanent magnet via bearings, at least one of the flange members is made of an organic polymer. A magnet roll characterized in that a narrow protrusion is formed on the inner circumferential surface of the flange member to abut on the outer circumferential surface of the support shaft of the permanent magnet.