JPH05142845A - Rotating body - Google Patents

Abstract

PURPOSE:To prevent the axial deviation of a rotating body at the time of its rotation in press contact with another rotating body by providing a specified deviation preventing member on the hollow cylinder of a rotating body. CONSTITUTION:A hollow cylinder 1 is elastically deformable in radial direction, and both its axial end parts are fitted into support members 2R, 2L, respectively. Shafts 3R, 3L are integrally provided to regulate the movement in shaft longitudinal direction (x), and two U-shaped sectional rubber films 4R, 4L having one-side ends opened and the other sides blocked are arranged in the manner that the blocked parts are butted to each other in the center part of the hollow cylinder 1. The opened end parts are adhered to the hollow cylinder 1. Thus, when another rotating body 6 is pressed onto the hollow cylinder 1 and rotated, and the hollow cylinder 1 is likely to be deviated in the shaft longitudinal direction (x), the deviation is returned by the elasticity of the rubber films 4R, 4L. Namely, even if a deviation is likely to be deviated, the hollow cylinder 1 receives the force of the direction returned to the original position by the deviation preventing member.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotating body used as a constituent member of an image forming apparatus such as a printer or a copying machine.

[0002]

2. Description of the Related Art Generally, in an electrophotographic process, a charging process for precharging a photosensitive member, an exposure process for exposing the charged photosensitive member with an optical image, and a developing process for visualizing a latent image carried on the photosensitive member by the exposure. , Transfer process to transfer visible image to paper, fixing process to fix image on paper after transfer, cleaning process to clean photoconductor after transfer, static elimination process to remove static electricity in preparation for next charging Therefore, the image formation by the dot printer is also performed through a process according to this.

In the image forming apparatus for performing these processes, the photosensitive member and the member for executing most of the above processes are constituted by the rotating member, and the photosensitive drum, the charging roller, and the developing roller are sequentially arranged. , Transfer roller,
It is composed of a rotating body such as a fixing roller and a charge eliminating roller.

Each of these rotating bodies is constructed so as to be in pressure contact with another rotating body, and the elastic displacement at the time of pressure contact is influenced by the degree of uniform contact in the axial direction.

For example, in the developing process, in order to perform sufficient development, it is necessary to obtain a predetermined developing contact width with a weak contact pressure for the contact state of the developing roller with the photosensitive drum. It is also introduced in a) and (b).

(A) Fuchio Takeda, Ko
ji Sakamoto and Kazuo Kobay
ashi, "NONMAGNETIC SINGLEC
OMPONENT PROCESS USING EL
ASTIC DE-VELOPMENT ROLLE
R ", EP-33 Japan hardCopy '
88, May 1988 (b) Toshihiko Takaya, Fuc
hio Takeda and Koji Sakamo
to, "DEVELOPMENT CHARACTER
ISTICS OF NONMAGNETICSING
LECOMPONENT PROCESS USING
ELASTIC DEVELOPMENTROLLE
R ", P193-195 SPESE'S 42nd
Annual Conference, May 14
-19, 1989 Therefore, it is necessary to bring the photosensitive drum and the developing roller into contact with each other with a weak contact pressure, but elastically deforming the developing roller as a means thereof is a factor because it disturbs the image, and thus there is a limit. Therefore, it is necessary to make the photosensitive drum elastically deformable.

As a technique for satisfying such demands, a hollow cylinder which is elastically deformable in the radial direction and a supporting member which surrounds and supports both outer circumferences of the hollow cylinder so as not to restrain the deformation of the hollow cylinder inward in the radial direction. A rotating body having is proposed.

[0008]

In the above-mentioned proposed technique, since the rotating body is not constrained in the supporting member, when it is pressed against another rotating body to rotate, a so-called deviation occurs in the axial direction. End up. If the rotating body is used as a photosensitive drum due to this deviation phenomenon, the image is disturbed at the time of transfer or the like.

Therefore, an object of the present invention is to provide a rotating body capable of preventing the deviation.

[0010]

In order to achieve the above object, the present invention provides a hollow cylinder with a deviation preventing member. Here, it is effective that the deviation preventing member is an elastic member that seals both ends of the hollow cylinder, and gas is sealed inside.

[0011]

If the deviation occurs, the hollow cylinder is applied with a force in the direction of being pulled back to the original position by the deviation preventing member.

[0012]

【Example】

1. An example corresponding to claim 1 (see FIGS. 1 and 2) In FIG. 1, reference numeral 1 denotes a hollow cylinder made of aluminum that is elastically deformable in the radial direction, and both end portions in the axial direction of the hollow cylinder. Are fitted in the supporting members 2R and 2L, respectively, and can be deformed inward in the radial direction.

The support member 2L is integral with the shaft 3L, the support member 2R is integral with the shaft 3R, and these shafts are concentrically provided and are axially supported by an immovable member (not shown) and have a longitudinal axis. Movement in direction X is restricted.

Inside the hollow cylinder 1, two rubber membranes 4R, 4L having a U-shaped cross section and one side open and the other side closed are arranged in a manner in which the closed portions are abutted at the central portion of the hollow cylinder. . Further, the outer circumference of the open end is adhered to the inner peripheral surface of the hollow cylinder 1 with an adhesive material. This adhesive portion is indicated by reference numeral 5.

Here, the closed portions of the rubber films 4R and 4L are in contact with each other as described above, and the shaft ends are in contact with the inside of each rubber film. As a result, it is as if the two rubber films were sandwiched between the shaft ends.

By the way, the wall thickness of the hollow cylinder 1 is 0.15 m.
m, outer diameter is 60 mm, length is 250 mm, and Young's modulus of this material, aluminum, is E = 7.03 × 10 ¹⁰ [P
a], and the rubber film used has a thickness of 0.02 mm and a Young's modulus of E = 1.5 × 10 ¹⁰ [Pa]. The rubber film may have holes.

Considering the case where the other rotating body 6 is pressed against the hollow rotating body 1 to be rotated under the above-described structure, the hollow rotating body 1 has a longitudinal axis due to factors such as cylindricity error of both rotating bodies. Even if the rubber film 4R, 4L is pushed toward the direction X, the deviation is returned due to the elasticity of the rubber films 4R and 4L. Therefore, in this example, the deviation preventing members are the rubber films 4R and 4L.

As a modified example, as shown in FIG. 2, rubber films 40R and 40L are fixed to both ends of the hollow cylinder 1 as a deviation preventing member so as to close the open end of the hollow cylinder 1, and The deviation can be prevented by setting the support members 20R and 20L so as to be in contact with the seats protruding inward from the central portions.

However, in this example, when the rubber membrane receives a force from the support member when a deviation occurs, the hollow cylinder directly receives a force inward in the radial direction, and therefore the hollow cylinder is likely to buckle in the axial longitudinal direction. Further, even if there is no deviation, the easiness of deformation changes in the axial direction when another rotating body is brought into contact.

In this respect, in the approach preventing member according to the example of FIG. 1, the rubber film is adhered to the inside of the end of the hollow cylinder, and the rubber film is in contact with the inside of the hollow cylinder up to the vicinity of the central part. As shown in the drawing, buckling does not occur because the Young's modulus of the rubber film is as small as four orders of magnitude even when the deviation occurs. In addition, uneven deformation inward in the radial direction does not occur.

2. Example corresponding to claim 2 (see FIG. 4) In this example, as shown in FIG. 4, the rubber films 400R and 400L are adhered to both ends of the hollow cylinder 1 to seal the inside of the hollow cylinder. Further, a gas 8 is enclosed in this closed chamber. The rubber film projects outward from the end of the hollow cylinder and is in contact with the inside of the supporting members 200L and 200R.
In this example, the rubber membrane should not have holes.

With this configuration, even if the rubber film is applied with a force from the support member due to the deviation, the hollow cylinder does not receive a force inward in the radial direction. Further, since the gas is enclosed in the hollow cylinder, when the deviation occurs, the deviation is returned by the increased pressure.

By changing the pressure of the gas to be enclosed, the contact width when the hollow cylinder comes into contact with another roller is changed with the contact pressure kept constant, without changing the material and wall thickness of the hollow cylinder. be able to.

[0024]

According to the present invention, deviation can be prevented.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a rotating body according to the present invention.

FIG. 2 is a cross-sectional view illustrating another example of a rotating body according to the present invention.

FIG. 3 is a cross-sectional view illustrating a deformed state of the rotating body according to the example of FIG.

FIG. 4 is a sectional view illustrating still another example of the rotating body according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hollow cylinder 4L Rubber film 4R (as a deviation preventing member) 4R (Rubber film as a deviation preventing member) 40L Rubber film 40R (As a deviation preventing member) 400L (As a deviation preventing member) ) Rubber film 400R (as a deviation prevention member)

Claims (2)

[Claims] 1. A rotating body having a hollow cylinder that is elastically deformable in the radial direction and a support member that surrounds and supports both outer peripheries of the hollow cylinder so as not to restrain the deformation of the hollow cylinder inward in the radial direction. A rotating body comprising a hollow cylinder provided with a member for preventing deviation of the hollow cylinder. 2. The rotating body according to claim 1, wherein the deviation preventing member is an elastic member that seals both ends of a hollow cylinder, and gas is sealed inside.