JPH11249364A - Rotary shaft supporting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the positional accuracy of one rotating member by reducing the backlash of a rotary shaft supporting device supporting the shaft of one rotating member which is pressed by the other rotating member. SOLUTION: This device is provided with a second rotating member 62 pressed by a first rotating member 61, a pair of inside bearings 63 rotatably supporting the respective both end parts of the shaft 58 of the member 62, a pair of outside bearings 64 attached to the outside of the respective bearings 63, and rotatable supporting the both end parts of the shaft 58 of the member 62, a sliding surface 63b formed on the outside surface of one bearing 63 of the bearings 63 and 64 supporting the member 62, a pair of guides 68 which is supported so that it can slide to the member 61 and can not rotate, and a pressing member 69a making elastic force for pressing the surface 63b to the guide 68, and to the member 61 act on one bearing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotating shaft supporting apparatus for rotatably supporting a shaft of a rotating member which is pressed against each other and rotates, and more particularly to a rotating shaft with reduced play and improved positioning accuracy of the shaft. The present invention relates to a shaft support device. When such a rotating shaft supporting device is used in an image forming apparatus such as an electrophotographic copying machine or a printer, the play of the rotating shaft supporting device of the rotating member which is pressed and rotated by each other is reduced to thereby reduce the play. Can be prevented from deteriorating the image quality.

[0002]

2. Description of the Related Art In an electrophotographic copying machine, a printer, or the like, when vibration occurs in rotation of a photoreceptor, unevenness occurs in the writing pitch of exposure scanning and unevenness in image quality. This uneven shading is called banding and is a factor in image quality deterioration. In particular, color copiers often use intermediate densities, as in photographic originals, and the shading of each color appears as a change in color. Therefore, there is a need to stabilize the rotational speed of the photoconductor more than black and white images. Strict. In the case of a conventional color copying machine, a flywheel is mounted on the rotation axis of the photoconductor in order to stabilize the rotation speed of the photoconductor and improve image quality. However, flywheels are not only heavy but also large in size and costly, so it is difficult to introduce them into small low-end machines. For this reason, conventional small low-end machines try to suppress the generation of vibration by improving the precision and rigidity of components such as gears that are the vibration source of the drive system that drives the photoconductor, but the performance is not sufficient. Not obtained.

In Japanese Patent Application No. 9-99079, as a technique for suppressing rotational vibration of a photosensitive member or the like, a friction roller having a large outer diameter is provided on a driven shaft such as a photosensitive member shaft, and the drive is performed between the rollers. A configuration in which friction is transmitted to a small-diameter friction roll on the axis of a rotary inertia body by friction has been considered. This is to increase the inertia effect by increasing the rotation of the driven shaft and transmitting it to the rotating inertial body, and to obtain the damping effect on the vibration or uneven rotation of the photoconductor, aiming at miniaturization of the inertial body. It is. In this case, it is known that increasing the transmission stiffness between the driven shaft and the inertia shaft is important for obtaining a high inertia effect, widening the vibration damping area and obtaining a good damping effect. .

In driving transmission by friction between a driving roll and a driven roll, it is necessary to apply a nip pressure in order to obtain a driving force.
As disclosed in Japanese Unexamined Patent Publication No. 943-94 and Japanese Unexamined Patent Application Publication No. 4-112144, there is a general example in which a roll fixed to a bearing or the like is configured to be capable of coming and going (contact, separation) with another roll and pressed by elastic force. Is often used. in this case,
Since there is play between the bearing portion and the mounting portion of the bearing in terms of component accuracy, the rotating shaft pressed at the time of driving transmission moves within the range of the play.

[0005]

FIG. 14 is an explanatory view of a play in a configuration in which the second rotating member is pressed against the first rotating member by an elastic force. FIG. 14A is an overall explanatory view, and FIG. 14B.
Is an enlarged view of a main part. In FIG. 14, the first rotating member 0
A bearing 03 is mounted on a shaft 02a of the second rotating member 02 that is pressed against 1. Flat sliding surfaces 03a, 03a are formed on the outer surface of the bearing 03.
The slide surfaces 03a, 03a of the bearing 03 are guides 06.
Are supported by the flat guide surfaces 06a, 06a so as to be slidable and separated from and accessible to the first rotating member 01. The bearing 03 is a pressing spring 0
7, the first rotating member 01 is pressed.

As shown in FIG. 14B, a play d1 exists between the shaft 02a and the bearing 03, and a play d2 exists between the slide surface 03a and the guide surface 06.
If a structure having such a play is used as a nip pressure pressurizing means of a friction roll for suppressing the rotational vibration, the play becomes a cause of lowering the transfer rigidity, so that the play is reduced to realize a higher transfer rigidity. We need a means to make it happen.
In addition, since there is a small amount of play between the bearing and the rotating shaft, it is necessary to further reduce the play in order to obtain a higher drive transmission rigidity.

FIG. 15 is an explanatory diagram of the prior art without play. As a means of reducing between the bearing and the bearing holder,
As shown in FIG. 15, a bearing 03 for rotatably supporting a shaft 02a of a second rotating member 02 pressed against the first rotating member 01.
Can be completely fixed to the frame 08 or the like. In this case, if driving is continued, the surfaces of the rolls 01 and 02 are worn, and if the roll diameter is reduced, the nip pressure is reduced. , 02.

In view of the above circumstances, the present invention provides the following (O0
1) and (O02) are to be described. (O01) To improve the positioning accuracy of the other rotating member by reducing the backlash of the rotating shaft supporting device that supports the shaft of the other rotating member pressed by one rotating member. (O02) The other rotating member pressed by one rotating member can be pressed with a uniform pressing force over a long period of time.

[0009]

Means for Solving the Problems Next, the present invention which has solved the above-mentioned problems will be described. Elements of the present invention include elements of the embodiments to facilitate correspondence with the elements of the embodiments described later. The sign of parentheses is added in parentheses. The reason why the present invention is described in correspondence with the reference numerals of the embodiments described below is to facilitate understanding of the present invention and not to limit the scope of the present invention to the embodiments.

(1st invention) In order to solve the aforementioned problem,
The rotating shaft support device of the first invention has the following requirements (A01) to (A01).
(A01) The second rotating member (6) pressed against the first rotating member (61, 76).
2, 77), (A02) the second rotating member (62, 77)
(A03) A pair of inner bearings (63), which rotatably support both ends of the shafts (58, 77a), are mounted on the outside of the inner bearings (63), and the second rotating member (62, 77). 77) A pair of outer bearings (64) rotatably supporting both ends of the shaft (58, 77a), (A04) an inner bearing (63) supporting the second rotating member (62, 77), and an outer bearing. (64) one bearing (6
Slide surface (63b) formed on the outer surface of 3), (A0
5) A pair of guides (68), (A) that slidably and non-rotatably support the slide surface (63b) of the one bearing (63) toward the first rotating member (61, 76).
06) Slide surface (63b) of the one bearing (63)
A pressing member (69) for applying an elastic force to the other bearing by pressing the guide member (68) against the guide (68) and pressing the first rotating member (61, 76).

(Operation of the First Invention)
In the rotating shaft support device of the invention, the pair of inner bearings (63)
Supports both ends of the shaft (58, 77a) of the second rotating member (62, 77) pressed against the first rotating member (61, 76), respectively, in a freely rotatable manner. A pair of outer bearings (64) mounted outside each of the inner bearings (63)
Are the shafts (58, 77) of the second rotating member (62, 77).
Both ends of a) are supported rotatably. A sliding surface (63b) formed on the outer surface of one of the inner bearing (63) and the outer bearing (64) that supports the second rotating member (62, 77) is a pair of guides (6).
According to 8), the slide surface (63b) of the one bearing (63) is slidably and non-rotatably supported toward the first rotating member (61, 76). A pressing member (69) for applying an elastic force to the other bearing presses the slide surface (63b) of the one bearing (63) against the guide (68) and the first rotating member (61, 7).
Press toward 6). The first rotating member (61, 7)
6) and the second rotating member (62, 7) pressed against the
If the contact portion of (7) is worn, the inner bearing (6)
The slide surface (63b) of (3) slides along the guide (68) to move the first rotating member (61, 7).
6) Move to the side. For this reason, the first rotating member (6
1, 76) and the second rotating member (62, 77) are always pressed with an appropriate pressing force even if their contact portions are worn. Therefore, a stable rotational force can be transmitted for a long period of time. Further, the second rotating member (62, 7)
The shaft (58, 77a) of 7) is supported without backlash by a contact portion with the inner bearing (63) and the outer bearing (64). Therefore, the shaft (58, 77a) of the second rotating member (62, 77) can rotate at a fixed position without rattling.

(Second Invention) A rotating shaft supporting device according to a second invention has the following requirements (B01) to (B06). (B01) First rotating member (61, 76) And (B02) a pair of bearings that rotatably support both ends of the shaft (58, 77a) of the second rotating member (62, 77). (7
1), (B03) the slide surface (71c) formed on the outer surface of the pair of bearings (71), and (B04) the slide surface (71c) of the bearing (71) with the first rotating member (61, 76). ), A pair of guides (68) slidably and non-rotatably supported toward the guide (68).
A pressing member (69) for applying an elastic force to the bearing (71) to press the bearing against the first rotating member (61, 76), and (B06) the first rotation by the pressing member (69). The second rotating member (6) is attached to the member (61, 76).
2, 77) when the second rotating member (62, 77) is pressed.
77), and a pair of inclined members which are in line contact with the shafts (58, 77a) and press the shafts (58, 77a) of the second rotating member (62, 77) toward the first rotating member (61, 76). The pair of bearings (71) having the shaft supporting surfaces (71a, 71b) formed.

(Operation of the Second Invention)
In the rotating shaft support device of the present invention, the slide surface (71
The pair of bearings (71) formed with c) is such that the slide surfaces (71c) of the bearings (71) are slidable toward the first rotating members (61, 76) by the guides (68) and cannot rotate. Supported as possible. The bearing (71)
The pressing member (69) for applying an elastic force to the guide (68) moves the slide surface (71c) of the bearing (71) to the guide (68).
To the first rotating member (61, 76). When the second rotating member (62, 77) is pressed against the first rotating member (61, 76) by the pressing member (69), a pair of inclined shaft support surfaces of the pair of bearings (71) are provided. 71a, 71b) is in line contact with the shaft (58, 77a) of the second rotating member (62, 77) to rotate the shaft (58, 77a) of the second rotating member (62, 77) by the first rotation. While pressing against the member (61, 76), the shaft (58, 77a) of the second rotating member (62, 77)
Are rotatably supported at both ends. When the contact portion between the first rotating member (61, 76) and the second rotating member (62, 77) pressed against the first rotating member (61, 76) is worn, the slide surface (71c) of the bearing (71) is fixed to the guide (6).
8), and slides along the first rotating member (6).
1,76). Therefore, the first rotating member (61, 76) and the second rotating member (62, 77)
Are always pressed with an appropriate pressing force even if their contact parts are worn. Therefore, a stable rotational force can be transmitted for a long period of time. Further, the second rotating member (6
The shafts (58, 77a) of (2, 77) are supported without play by the contact portions with the pair of inclined bearing surfaces. Therefore, the shaft (58, 58) of the second rotating member (62, 77)
77a) can rotate at a certain position without rattling.

(Third Invention) The rotating shaft supporting device according to the third invention has the following requirements (C01) to (C05). (C01) First rotating member (61, 76) And (C02) a pair of bearings rotatably supporting both ends of the shafts (58, 77a) of the second rotating members (62, 77). (8
1), (C03) the sliding surface (81b) formed on the outer surface of the pair of bearings (81), and (C04) the sliding surface (81b) of the bearing with the first rotating member (61, 7).
6) A pair of guides (68) slidably and non-rotatably supported toward (6), (C05) a slide surface (81b) of the bearing is pressed against the guide (68) and the first
A pressing member (69) for applying an elastic force pressing the rotating member (61, 76) to the bearing.

(Operation of the Third Invention) The third embodiment having the above-described configuration
In the rotating shaft support device of the invention, the slide surface (81
The pair of bearings (81) formed with b) are pressed against the first rotating member (61, 76) by the second rotating member (6).
2, 77) are rotatably supported at both ends of the shaft (58, 77a). The pair of guides (68) is configured to slide the slide surface (81b) of the bearing to the first rotating member (61, 61).
A pressing member (69) for supporting an elastic force on the bearing so as to be slidable and non-rotatable toward (76).
Presses the slide surface (81b) of the bearing against the guide (68), and presses the first rotating member (61, 76).
Press toward. When the contact portion between the first rotating member (61, 76) and the second rotating member (62, 77) pressed against the first rotating member (61, 76) is worn, the sliding surface (81) of the bearing is used.
b) slides along the guide (68),
It moves to the side of the first rotating member (61, 76). Therefore, the first rotating member (61, 76) and the second rotating member (62, 77) are always pressed with an appropriate pressing force even if their contact portions are worn. Therefore, a stable rotational force can be transmitted for a long period of time. Further, the bearing for supporting the shaft (58, 77a) of the second rotating member (62, 77) has a sliding surface (81b) which is constantly pressed by the guide (68). There is no play between them. For this reason, the bearing of the second rotating member (62, 77) does not rattle at a fixed position, and the shaft (5,
8,77a) can be supported.

[0016]

Next, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to the following embodiments. (Embodiment 1) FIG. 1 is an overall explanatory view of an image forming apparatus (color copying machine) according to an embodiment of the present invention. In FIG. 1, an image forming apparatus F has a UI (user interface) having a copy start key, a numeric keypad, and the like (not shown) at an upper part thereof.
And a transparent platen glass 2 on which a document (not shown) is placed. A document illumination unit 3 that scans the document while illuminating the document is arranged below the platen glass 2. The document illumination unit 3 includes a document illumination light source 4.
And a first mirror 5. A mirror unit 6 that moves at half the speed of the original illumination unit 3 is disposed below the platen glass 2. The mirror unit 6 includes a second mirror 7 and a third mirror 8 that reflect light emitted from the illumination light source 4 and sequentially reflected by the original and the first mirror 5 (that is, original image light). .

The original image light reflected by the third mirror 8 passes through an image forming lens 9 and is read as R, G, B analog signals by a CCD (color image reading sensor). C
The R (red), G (green), and B (blue) image signals read by the CD are input to the IPS. The IPS includes an image read data output unit 11 that converts an analog electric signal of an R, G, B read image obtained by the CCD into a digital signal and outputs the digital signal, and converts the RGB image data into a K signal.
(Black), Y (yellow), M (magenta), and C
An image data output unit 12 converts the image data into (cyan) image data, performs data processing such as density correction and enlargement / reduction correction, and outputs the image data as writing image data (laser driving data). The image data output means 12 outputs the K,
An image memory 13 for temporarily storing Y, M, and C image data is provided.

The IPS write image data output means 12
The image write data (laser drive data) of four colors of K, Y, M, and C output by the laser drive signal are input to the laser drive signal output device 14. The laser drive signal output device 14 outputs a laser drive signal of an image of each color component of K, Y, M, and C in accordance with the input image data at a predetermined timing to an ROS (optical scanning device, that is, a latent image forming device). ). The RO
S scans the electrostatic latent image writing position Q1 of the rotating image carrier 16 with the laser beam L modulated by the laser drive signal output from the laser drive signal output device 14.

A rotary developing unit (developing unit) for developing the electrostatic latent image into a toner image is provided in a developing area Q2 on the downstream side of the latent image writing position Q1 along the moving direction of the image carrier 16. (Device) 18 is disposed. The developing unit 18 has developing devices 18k, 18y, 18m, and 18c of four colors of K, Y, M, and C mounted around a rotating shaft 18a. The four color developing units 18k, 18y, 18m and 18c are sequentially arranged in the developing area Q2.
It is configured to move to. The developing unit 18k,
Reference numerals 18y, 18m, and 18c denote electrostatic latent images on the image carrier 16 as K (black), Y (yellow), M (magenta),
This is a device for developing toner images of each color (cyan). The toner image forming apparatus (14 to 18 + ROS) is constituted by the elements indicated by the reference numerals 14 to 18, ROS and the like.

In FIG. 1, the surface of the image carrier 16 is uniformly charged (−650 V in this example) with a charge of a predetermined polarity by a charger 17 and a laser beam L modulated by a first color image signal. An electrostatic latent image corresponding to the image of the first color (for example, K (black)) is formed on the surface of the image carrier by the writing scan, and the surface potential of the image carrier 16 is written by the laser beam L at this time. (−200 V in this example), an image is formed by the potential, that is, an electrostatic latent image is formed at the latent image writing position Q1, K, Y, M, C.
Are sequentially written in this order, and are sequentially rotated and moved to the developing area Q2.
Developed sequentially at 18m and 18c.

In the primary transfer area Q3 in which the toner images of the respective colors sequentially formed on the surface of the image carrier 16 are superimposedly transferred onto the intermediate transfer belt B, one side is provided on the back side of the intermediate transfer belt B.
A next transfer roll (primary transfer device) T1 is provided. 1
Intermediate transfer belt B and image carrier 1 in next transfer area Q3
6 and the contact pressure was almost 0, and the nip width was 0.5.
３3 mm. To the primary transfer roll T1, a transfer bias voltage having a polarity opposite to the charging polarity of the toner image on the surface of the image carrier 16 is supplied to the power supply E1 for the primary transfer unit of the power supply E for transfer.
Is applied. The toner images of K, Y, M, and C sequentially developed on the image carrier 16 by the primary transfer roll T1 to which the transfer bias voltage is applied are transferred every time the intermediate transfer belt B rotates once. Intermediate transfer belt B for each color
The primary transfer is successively superposed on the top. On the downstream side of the primary transfer area Q3 along the surface of the image carrier 16, an image carrier cleaner 19 for collecting residual toner on the surface of the image carrier 16, and a charge on the surface of the image carrier 16 is removed. The static eliminators 20 are sequentially arranged.

The intermediate transfer belt B includes a driving roll 2
5, tension roll 26, idler roll 27, 28
And rotatably supported by belt support rolls 25 to 29 having an inner transfer roll (backup roll) 29, and driven by a drive device (not shown) at approximately the same speed as the image carrier 16 by the drive roll 25 indicated by an arrow. Rotate in direction A.

In the secondary transfer area Q4 set on the moving path of the intermediate transfer belt B, the intermediate transfer belt B
The outer secondary transfer roll 30 is disposed on the side facing the inner secondary transfer roll 29. An electrode roll 31 is in contact with the inner secondary transfer roll 29, and a toner on the intermediate transfer belt B is contacted with the electrode roll 31 by a secondary transfer unit power supply E 2 of a transfer power supply E controlled by a controller C. And a secondary transfer bias voltage having the same polarity as the charging polarity is applied, and the toner image that has been primary-transferred and superimposed on the intermediate transfer belt B is secondarily transferred onto the recording paper S at once. The elements indicated by the reference numerals 29 to 31 constitute the secondary transfer unit T2. The outer secondary transfer roll 30 is movable together with a transfer roll cleaner 33 for cleaning the surface between a separation position apart from the inner secondary transfer roll 29 and a transfer operation position pressed by the inner secondary transfer roll 29. It is. Further, a belt cleaner 35 for removing residual toner on the surface of the intermediate transfer belt B is provided downstream of the outer secondary transfer roll 30 in the transport direction of the intermediate transfer belt B. It is arranged so as to be movable between a position and a remote position.

The recording paper S taken out of the paper feed tray 41 is conveyed by a pickup roll 42 and a separation roll 43, and once stopped by a registration roll 44, passes through a guide conveyance path 45 at a predetermined timing, and is subjected to the secondary transfer. It is transported to the area Q4. The unfixed toner image on the intermediate transfer belt B is secondarily transferred to the recording sheet S by the secondary transfer unit T2 when passing through the secondary transfer area Q4. The recording sheet S to which the unfixed toner image has been transferred moves along the upper surface of the sheet guide member 46, and is further conveyed to the fixing position Q5 through the sheet conveying belt 47. Recording paper S
When the sheet passes through the fixing area Q5, the unfixed toner image on the recording sheet S is fixed by the fixing device 48 and is discharged to the discharge tray 49.

FIG. 2 shows an apparatus for supporting a rotating shaft of a friction roll pressed by a pressing member on a friction roll (friction roll mounted on the rotating shaft of the image bearing member) mounted on the rotating shaft of the image bearing member. It is explanatory drawing of Example 1). FIG. 3 is an explanatory view of a guide that slidably supports the inner bearing and a pressing member that presses the outer bearing. FIG. 3A is an overall explanatory view.
FIG. 3B is an enlarged view of a main part of FIG. 3A. FIG. 4 is an enlarged view of a main part of FIG. In FIG. 2, the image carrier 16
Of the rotating shaft 51 through a coupling 52
It is connected to. The rotating shaft 53 is rotatably supported by the frames F1 and F2 via bearings. The frames F1 and F2 have a motor output shaft 56, a transmission gear shaft 5
7 is rotatably supported. Further, the frame F
Slots F1a and F2a through which the inertial body support shaft 58 penetrates 1 and F2.
Are formed. The axial position of the inertial body support shaft 58 with respect to the frames F1, F2 is held at a predetermined position by retaining members 59, 59 fixed to the inertial body support shaft 58.

The motor output shaft 56 is driven to rotate by a motor M supported by a frame F2. A gear G1 is mounted on the motor output shaft 56. A large-diameter gear G2 and a small-diameter gear G3 that mesh with the gear G1 are mounted on the transmission gear shaft 57. A gear G4 meshing with the small-diameter gear G3 and a large-diameter friction roll (first rotating member) 61 are mounted on the rotating shaft 53. A small-diameter friction roll (second rotating member) 62 that comes into frictional contact with the large-diameter friction roll 61, and a pair of inner bearings 63, 6 disposed on both sides of the small-diameter friction roll 62 are mounted on the inertial body support shaft 58.
3. A pair of outer bearings 64, 64 provided outside the pair of inner bearings 63, 63, and the frame F
An inertia body 65 arranged between the outer bearing 64 and the outer bearing 64 is mounted. As shown exaggeratedly in FIG. 7, there is a gap between the bearing surface 63a of the inner bearing 63 and the rotating shaft 58, and there is also a gap between the bearing surface 64a of the outer bearing 64 and the rotating shaft 58. There is. In FIG. 7, the bearing surface 63a of the inner bearing 63 and the rotating shaft 58 are located at the point of action P.
2 ', and the bearing surface 64a of the outer bearing 64 and the rotating shaft 58 are in contact at the point of action P3'.

In FIG. 4, rotating shafts 5 are provided on both sides of inner bearings 63, 63 and outer bearings 64, 64, respectively.
A retaining ring 67 locked to 8 is arranged. 3 and 4, flat sliding surfaces 63b, 63b are formed on the outer surface of the inner bearing 63. The slide surface 6
One of the slide surfaces 63b (the slide surface formed on the lower side) 63b of the guides 3b and 63b is slidably supported by the support surface 68a of the guide 68. Support surface 68a of the guide 68
Supports the inner bearing 63 so as to be slidable in a direction to approach or separate from the large-diameter friction roll (first rotating member) 61. The outer bearing 64 is pressed by a pressing member 69 constituted by a compression spring. The pressing member 69 presses the outer bearing 64 to move the sliding surface 63 b of the inner bearing 63 to the guide 68.
Of the large-diameter friction roll (first
An elastic force that presses toward the rotating member is applied. FIG.
FIG. 7 is a diagram showing an arrangement position of a pressing member 69. As shown in FIG. 5, the disposition position of the pressing member 69 is determined by a straight line extending in a direction away from the large-diameter friction roll 61 along the slide surface 63b and a straight line perpendicular to the straight line and passing through the rotation shaft 58. Are arranged in the range of the angle θ between them.

(Operation of Embodiment 1) FIG. 6 is an explanatory view of an enlarged operation of the bearing of the embodiment 1. The operation point P1 of the force acting on the small-diameter friction roll 62 and the operation point P acting on the inner bearing 63 are shown.
FIG. 2 is a diagram showing an action point P3 acting on the outer bearing 64. FIG. 7 is an explanatory diagram of an enlarged operation of the first embodiment, in which the point P1 of the force acting on the small-diameter friction roll 62, the point P2 'of the inner bearing 63 acting on the rotating shaft 58, and the outer bearing 64 acting on the rotating shaft 58. FIG. 9 is a diagram showing an action point P3 'of FIG. The action point P3 is pressed by the pressing member 69 on the outer surface of the outer bearing 64, and the inner face 64a of the outer bearing 64 is
At 3 ', the rotating shaft 58 is pressed. Also, the rotation shaft 58
Presses the bearing surface 63a of the inner bearing 63 at the point of action P2 'and simultaneously receives a reaction force from the bearing surface 63a. That is, the rotating shaft 58 receives a force at the action points P2 'and P3', and the force acting on the rotating shaft 58 is transmitted to the small-diameter friction roll 62 and the action point P
In 1, the small-diameter friction roll 62 is pressed against the large-diameter friction roll 61.

In FIG. 7, when the contact portion between the large-diameter friction roll 61 and the small-diameter friction roll 62 is worn, the sliding surface 63b of the inner bearing 63 is
8 by sliding on the support surface 68a to move to the large-diameter friction roll 61 side. For this reason, the large-diameter friction roll 61 and the small-diameter friction roll 62 are always pressed with an appropriate pressing force even if their contact portions are worn. Therefore, a stable rotational force can be transmitted for a long period of time. The rotating shaft 58 is supported without play by the action points P2 'and P3' with the inner bearing 63 and the outer bearing 64. Therefore, the rotating shaft 58 can rotate at a fixed position without rattling.

(Embodiment 2) FIG. 8 is an explanatory view of a guide for slidably supporting the bearing of Embodiment 2 and a pressing member for pressing the bearing, and corresponds to FIG. 3B of Embodiment 1 above. FIG. 9 shows a device for supporting a rotating shaft of a small-diameter friction roll pressed by a pressing member on a large-diameter friction roll (a friction roller mounted on an image-bearing-body rotating shaft) mounted on a rotating shaft of an image carrier. FIG. 4 is an explanatory view of Embodiment 1) and corresponds to FIG. 4 of Embodiment 1; In the description of the second embodiment, components corresponding to the components of the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted. The second embodiment differs from the first embodiment in the following points, but has the same configuration as the first embodiment in other points. In the second embodiment, the inner bearing 63 of the first embodiment is used.
A pair of bearings 71 are provided instead of the outer bearings 64. The pair of bearings 71 are in linear contact with a shaft 58 of the second rotating member 62 and a pair of inclined shaft supporting surfaces 7 that rotatably support the shaft 58 of the second rotating member 62.
1a and 71b. As shown in FIG. 8, the shaft 58 of the second rotating member is in contact with the shaft support surfaces 71a, 71b and the point of action P.
They are in contact at 2 'and P3'.

Each of the pair of bearings 71 has a slide surface 71c formed on the outer surface thereof and guided by a pair of guides 68. The guides 68 are supported by a frame (not shown). The pressing member 69 is
An elastic force that presses the slide surface 71c of the bearing 71 against the guide 68 and presses the bearing against the first rotating member 61 is applied to the bearing 71. The pair of bearings 7
The first shaft supporting surfaces 71a and 71b are in line contact with the shaft 58 of the second rotating member 62 when the second rotating member 62 is pressed against the first rotating member 61 by the pressing member 69. The shaft 58 of the two rotating member 62 is connected to the first rotating member 6
Press towards 1.

(Effects of the Second Embodiment) In the second embodiment, similarly to the first embodiment, when the contact portion between the large-diameter friction roll 61 and the small-diameter friction roll 62 is worn, the inner bearing 6 is used.
In 3, the slide surface 71 c slides on the support surface 68 a of the guide 68 and moves to the large-diameter friction roll 61 side. For this reason, the large-diameter friction roll 61 and the small-diameter friction roll 62 are always pressed with an appropriate pressing force even if their contact portions are worn. Therefore, a stable rotational force can be transmitted for a long period of time. The rotation shaft 58 is connected to the shaft support surfaces 71a, 71b and the point of action P.
2 'and P3' make contact and are supported without play. Therefore, the rotating shaft 58 can rotate at a fixed position without rattling.

(Embodiment 3) FIG. 10 is an explanatory view of Embodiment 3 in which the rotating shaft support device of the present invention is applied to a paper transport roll.
FIG. 10A is a diagram corresponding to FIG. 6 of the first embodiment, FIG. 10A is a diagram illustrating a registration roll for conveying a sheet, and FIG.
It is a perspective view of a registration roll shown in OA. FIG. 11 is an explanatory view of a support device for the rotation shaft of the sheet transport roll shown in the drawing 10, and corresponds to FIG. 6 of the first embodiment. In the description of the third embodiment, components corresponding to the components of the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted. The third embodiment is different from the first embodiment in the following points, but is otherwise different from the first embodiment.
It is configured similarly to. In the third embodiment, the present invention is applied to the registration roll 44 for conveying the sheet S shown in FIG. Referring to FIG.
Is composed of a drive roll 76 having a drive roll shaft 76a and a driven roll 77 having a driven roll shaft 77a. The shaft 76a of the drive roll 76 is connected to the output shaft of the motor M1 via a gear train G. Therefore, the shaft 76a and the driven roll 76 rotate when the motor M1 rotates.

In FIG. 11, both ends of the shaft 77a are connected to the inner bearing 63 and the outer bearing 6 as in the first embodiment.
4 rotatably supported. As in FIG. 6 of the first embodiment, in FIG.
, An action point P2 acting on the inner bearing 63, and an action point P3 acting on the outer bearing 64 are shown. Although not shown, the shaft 77a of the third embodiment is not shown.
The inner bearing 6 is similar to the first embodiment (see FIG. 7).
3 and the point of action P2 'and P
Supported without play by 3 '. Therefore, the shaft 77a can rotate at a fixed position without rattling.
When the contact portion between the drive roll 76 and the driven roll 77 is worn, the slide surface 63b of the inner bearing 63 slides on the support surface 68a of the guide 68 and moves to the drive roll 76 side. For this reason, the drive roll 76 and the driven roll 77 are always pressed with an appropriate pressing force even if their contact portions are worn. Therefore, a stable rotational force can be transmitted for a long period of time.

(Embodiment 4) FIG. 12 is an explanatory view of Embodiment 4 in which the rotating shaft support device of the present invention is applied to a paper transport roll.
FIG. 9 is a view corresponding to FIG. 8 of the second embodiment. In the description of the fourth embodiment, the same reference numerals are given to the components corresponding to the components of the second embodiment, and the detailed description is omitted. The fourth embodiment is different from the second embodiment in the following points.
Although the configuration is different from that of the second embodiment, the other configuration is the same as that of the second embodiment. In the fourth embodiment, the present invention is applied to the registration rollers 44 shown in FIG.

In FIG. 12, both ends of the shaft 77a are rotatably supported by the same bearings 71 as in the second embodiment. In FIG. 12 of the fourth embodiment, the shaft 77 a of the driven roll 77 is
The contact points a2 and P3 'are supported at the action points P2' and P3 'without play. Therefore, the shaft 77a can rotate at a fixed position without rattling. In addition, the driving roll 76
When the contact portion of the driven roll 77 is worn out, the bearing 71 has its sliding surface 71c
Slides on the supporting surface 68a of the
Move to the 6 side. For this reason, the drive roll 76 and the driven roll 77 are always pressed with an appropriate pressing force even if their contact portions are worn. Therefore, a stable rotational force can be transmitted for a long period of time.

(Embodiment 5) FIG. 13 is an explanatory view of Embodiment 5 of a rotary shaft supporting device according to the present invention, corresponding to FIG. 3 of Embodiment 1 described above, and FIG. 13A slidably supports a bearing. FIG. 13A is an overall explanatory view of a guide to be pressed and a pressing member for pressing the outer bearing, and FIG. 13B is an enlarged view of a main part of FIG. 13A. In the description of the fifth embodiment, the same reference numerals are given to the components corresponding to the components of the first embodiment, and the detailed description is omitted. The fifth embodiment differs from the first embodiment in the following points.
In other respects, the configuration is the same as that of the first embodiment. In the fifth embodiment, the outer bearing 64 of the first embodiment is omitted, and the pressing member 69 pressing the outer bearing 64 presses the bearing 81 corresponding to the inner bearing 63 of the first embodiment. The slide surface 81b of the bearing 81 is constantly pressed against the support surface 68a of the guide 68 by the pressing member 69.

(Function of Embodiment 5) In Embodiment 5, the slide surface 81b of the bearing 81 is constantly pressed against the support surface 68a of the guide 68 by the pressing member 69. That is, the bearing 81 does not come into contact with the support surface 68b (see FIG. 13B) of the guide 68 that faces the support surface 68a, and is constantly pressed against the support surface 68a. Therefore, there is no backlash between the bearing 81 and the guide 68, so that the backlash can be reduced as compared with the prior art shown in FIG. Therefore, the shaft 58 is less likely to rattle as compared with the prior art, and can rotate at a stable position.

(Modifications) Although the embodiments of the present invention have been described in detail, the present invention is not limited to the above-described embodiments, but falls within the scope of the present invention described in the appended claims. Thus, various changes can be made. Modified embodiments of the present invention will be exemplified below. (H01) In the present invention, besides solid bearings, bearings such as ball bearings and roller bearings can be used.

[0040]

The sheet processing apparatus of the present invention has the following effects. (E01) The positioning accuracy of the other rotating member can be improved by reducing the backlash of the rotating shaft supporting device that supports the shaft of the other rotating member pressed by one rotating member. (E02)
The other rotating member pressed by one rotating member can be pressed with a uniform pressing force over a long period of time.

[Brief description of the drawings]

FIG. 1 is an overall explanatory diagram of an image forming apparatus (color copier) according to an embodiment of the present invention.

FIG. 2 is a device (rotary shaft support device) that supports a rotary shaft of a friction roll pressed by a pressing member on a friction roll (friction roll with an image bearing member rotating shaft) mounted on the rotating shaft of the image carrier. It is explanatory drawing of Example 1).

3A and 3B are explanatory views of a guide for slidably supporting an inner bearing and a pressing member for pressing an outer bearing. FIG. 3A is an overall explanatory view, and FIG. 3B is an enlarged view of a main part of FIG. 3A.

FIG. 4 is an enlarged view of a main part of FIG. 2;

FIG. 5 is a view showing an arrangement position of a pressing member 69.

FIG. 6 is an explanatory diagram of an enlarged action of the bearing of the first embodiment, in which an action point P1 of a force acting on the small-diameter friction roll 62, an action point P2 acting on the inner bearing 63, and an action acting on the outer bearing 64; It is a figure showing point P3.

FIG. 7 is an explanatory diagram of an enlarged action of the first embodiment, in which a point of action P1 of a force acting on a small-diameter friction roll 62, a rotation shaft 58;
FIG. 10 is a view showing an operation point P2 'of the outer bearing 64 acting on the rotation shaft 58 of the inner bearing 63 acting on the rotating shaft 58.

FIG. 8 is an explanatory view of a guide that slidably supports the bearing and a pressing member that presses the bearing according to the second embodiment, and corresponds to FIG. 3B of the first embodiment.

FIG. 9 is an apparatus (rotation) for supporting a rotation shaft of a small-diameter friction roll pressed by a pressing member on a large-diameter friction roll (a friction roller mounted on an image-bearing-body rotation shaft) mounted on a rotation shaft of an image-bearing member. FIG. 6 is an explanatory view of Embodiment 1) of the shaft support device, corresponding to FIG. 4 of Embodiment 1;

FIG. 10 is an explanatory view of a third embodiment in which the rotating shaft support device of the present invention is applied to a paper transport roll.
10A is a diagram corresponding to FIG. 6, FIG. 10A is a diagram illustrating a registration roll that conveys a sheet, and FIG. 10B is a perspective view of the registration roll illustrated in FIG. 10A.

FIG. 11 is an explanatory diagram of a support device for a rotation shaft of a sheet transport roll shown in the drawing 10 and is a diagram corresponding to FIG. 6 of the first embodiment.

FIG. 12 is an explanatory view of a fourth embodiment in which the rotating shaft support device of the present invention is applied to a paper transport roll.
FIG. 9 is a view corresponding to FIG.

FIG. 13 is an explanatory view of Embodiment 5 of the rotating shaft support device of the present invention, corresponding to FIG. 3 of Embodiment 1; FIG. 13A is a guide for slidably supporting a bearing and an outer side; FIG. 13 is an explanatory diagram of a pressing member that presses a bearing.
13A is an overall explanatory view, and FIG. 13B is an enlarged view of a main part of FIG. 13A.

14 is an explanatory diagram of a play in a configuration in which the second rotating member is pressed against the first rotating member by an elastic force, FIG. 14A is an overall explanatory diagram, and FIG. 14B is an enlarged view of a main part.

FIG. 15 is an explanatory diagram of a conventional technique without play.

[Description of Signs] 58, 77a: shafts of second rotating members (62, 77), 61, 76: first rotating members, 62, 77: second rotating members, 63: inner bearings, 63b: sliding surfaces, 64 ... Outer bearing, 68 ... Guide, 69 ... Pressing member, 71 ... Bearing, 71c ... Sliding surface, 71a, 71b ... Sloped shaft supporting surface, 81 ... Bearing, 81b ... Sliding surface.

Claims (3)

[Claims] 1. A rotating shaft supporting device having the following requirements (A01) to (A06): (A01) a second rotating member pressed against a first rotating member; A pair of inner bearings for rotatably supporting both ends of the shaft of the second rotating member, respectively (A03) mounted on the outside of each of the inner bearings, and rotatably supporting both ends of the shaft of the second rotating member; A pair of outer bearings, (A04) a slide surface formed on the outer surface of one of the inner bearing and the outer bearing for supporting the second rotating member, and (A05) a slide surface of the one bearing to the first bearing. A pair of guides slidably and non-rotatably supported toward the rotating member, (A0
6) A pressing member that presses the sliding surface of the one bearing against the guide and applies an elastic force that presses the sliding surface toward the first rotating member to the other bearing. 2. A rotating shaft supporting device having the following requirements (B01) to (B06): (B01) a second rotating member pressed against a first rotating member; A pair of bearings rotatably supporting both ends of the shaft of the second rotating member, (B03) a sliding surface formed on the outer surface of the pair of bearings, and (B04) a sliding surface of the bearing for the first rotation. (B05) a pair of guides slidably and non-rotatably supported toward the member, and (B05) an elastic force that presses the slide surface of the bearing against the guide and presses the bearing against the first rotating member is applied to the bearing. Pressing member,
(B06) When the second rotating member is pressed against the first rotating member by the pressing member, the second rotating member is in line contact with the axis of the second rotating member and is directed toward the first rotating member. A pair of bearings having a pair of inclined shaft support surfaces that press and press. 3. A rotating shaft support device having the following requirements (C01) to (C05): (C01) a second rotating member pressed against a first rotating member; A pair of bearings rotatably supporting both ends of the shaft of the second rotating member, (C03) a sliding surface formed on the outer surface of the pair of bearings, and (C04) a sliding surface of the bearing for the first rotation. (C05) a pair of guides slidably and non-rotatably supported toward the member, and (C05) an elastic force which presses the slide surface of the bearing against the guide and presses against the first rotating member acts on the bearing. Pressing member.