JP3632144B2 - Driving device for image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an improvement in a driving device that rotationally drives various rotation portions in an image forming apparatus, particularly an image forming apparatus that forms an image by an electrophotographic method, that is, a photosensitive member, a developing device, a fixing device, and a cleaning device.
[0002]
[Prior art]
The driving device that transmits the power of the motor to the rotating portion of the image forming apparatus is usually arranged with electric wiring in a driving portion space partitioned from the image forming portion by a panel. Transmission of power from the drive unit space to the image forming unit is usually performed by a shaft penetrating the panel, a gear integrated with the shaft, a coupling, or the like.
[0003]
A conventional example of a drive device that transmits power from the drive unit space to the image forming unit will be described with reference to FIG. The rotational driving force transmitted from the motor M via a gear system (not shown) is transmitted from the gear G1 to the gear G3 via the gear G2. Although not shown in the figure, for example, a gear provided on the rotation shaft of the developing sleeve of the developing device meshes with the gear G3. The gear G1 is rotatably supported by a fixed shaft A1 supported by support panels P1 and P2, and the gears G2 and G3 are supported by a rotation shaft A2 rotatably supported by bearings B1 and B2 on the support panels P1 and P2. And is supported in one piece.
[0004]
[Problems to be solved by the invention]
In the drive unit as described above, the rotation shaft A2 is used as a mounting structure for the gears G2 and G3 that transmit power from the drive unit space SD to the image forming unit SG partitioned by the space and the panel P2 to the image forming apparatus. , The bearings B1, B2, and the gears G2, G3 of the rotary shaft A2 require pins H1, H2 for fixing the gears G2, G3 integrally to the shaft A2 and the locking members E1, E2, E3 of the shaft A2, and the structure becomes complicated. As the number of parts increases, the number of assembly steps also increases, resulting in an increase in manufacturing cost.
[0005]
Accordingly, an object of the present invention is to solve the above-described problems in the prior art, and it is possible to reduce the number of component parts, improve the assemblability, and reduce the manufacturing cost of the image forming apparatus. Another object of the present invention is to provide a drive device for an image forming apparatus.
[0006]
[Means for Solving the Problems]
The object of the present invention is as follows.
Support panel (21),
Auxiliary panel (22),
Fixed shafts (29, 33) fixed to the auxiliary panel; and
Driving force transmission means (25, 31),
The driving force transmission means (25, 31)
Gear portions (251, 311) positioned between the support panel (21) and the auxiliary panel (22),
Gear portions (252, 312) projecting on the opposite side of the surface of the support panel (21) facing the auxiliary panel,
Cylindrical portions (253, 313) rotatably supported by bearings (211) provided on the support panel (21);
Bearings (254, 314) rotatably supported by the fixed shafts (29, 33),
Have
The driving force transmission means (25, 31) is constituted by an integral part made of a slidable resin having the protruding gear part (252, 312) on the opposite side and the cylindrical part (253, 313). In addition, the outer diameter of the cylindrical portion (253, 313) is larger than the outer diameter of the protruding gear portion (252, 312) on the opposite side .
Achieved by:
[0007]
DETAILED DESCRIPTION OF THE INVENTION
(Image forming device)
Embodiments will be described below with reference to the drawings. Before describing each embodiment, an image forming apparatus in which the present invention is used will be described.
[0008]
FIG. 2 schematically shows an example of such an image forming apparatus.
[0009]
The photosensitive drum 1 rotates clockwise as indicated by an arrow, and according to the rotation, uniform charging by the charger 2, image exposure by the exposure light 3, and development by the developing device 4 are performed. A toner image is formed on. The toner image formed on the photosensitive drum 1 is transferred onto the transfer paper supplied by the paper feed roller 8 by the transfer separation device 5 and fixed by the fixing device 7. The photosensitive drum 1 that has passed the transfer position is cleaned by the cleaning device 6.
[0010]
The driving device of the present invention includes the photosensitive drum 1, the developing device 4, particularly the developing sleeve of the developing device, the developer stirring member or the toner replenishing member, the cleaning device 6, particularly the toner discharging member, and the fixing device in the image forming apparatus. It is used as a driving device for the device 7, particularly its fixing roller, paper feed roller 8, and other rotating members.
[0011]
(Embodiment 1)
Embodiment 1 of the present invention will be described with reference to FIG.
[0012]
FIG. 3 is a cross-sectional view of the drive device for the photosensitive drum 1 according to the first exemplary embodiment of the present invention. The gear trains 23, 24, 25 are arranged between two parallel support panels 21 and auxiliary panels 22 provided in the image forming apparatus. The rotating member 23 has gear portions 231 and 232 and is rotatably supported by a fixed shaft 27 supported by the support panel 21 and the auxiliary panel 22. The rotating member 24 has gear portions 241 and 242 and is rotatably supported by a fixed shaft 28 supported by the support panel 21 and the auxiliary panel 22. The rotating member 25 is an example of a driving force transmitting means that constitutes a main part of the present invention. The rotating member 25 includes gear portions 251 and 252 and a cylindrical portion 253, and is attached to a fixed shaft 29 supported by the support panel 21 and the auxiliary panel 22. It is supported rotatably.
[0013]
The rotating member 25 is rotatably supported at its outer periphery of the cylindrical portion 253 by a bearing 211 formed by drawing the support panel 21, and further, a bearing 254 formed on the inner periphery thereof is rotatable on the fixed shaft 29. It is supported. In this way, the rotating member 25 is rotatably supported at two axial positions. In a portion other than the bearing 254 on the inner periphery of the rotating member 25, a clearance 255 larger than the clearance between the bearing 254 and the fixed shaft 29 is provided between the fixed shaft 29. Such a rotation support structure ensures stable rotation of the rotation member 25. The cylindrical portion 253 and the gear portions 251 and 252 are formed so that the diameter D1 of the cylindrical portion 253 of the rotating member 25 is larger than the outer diameter D2 of the gear portions 251 and 252 of the rotating member 25. By making the outer diameter D1 of the cylindrical portion 253 larger than the outer diameter D2 of the gear portion 252, the rotating member 25 can fit the cylindrical portion 253 into the bearing 211, and the assembly of the rotating member 25 is facilitated.
[0014]
The image forming portion 11 of the photosensitive drum 1 is integrally fixed to a rotating member 26 that engages with a gear portion 252 and is supported by a rotating shaft 262 that is rotatably supported by a support panel 21 by a bearing 212. In addition, it is desirable that the length D3 in the rotation axis direction of the rotating member 25 of the bending portion forming the bearing 211 is larger than the thickness of the support panel 21. By using such a length, the bearing surface formed by drawing is formed with high accuracy.
[0015]
A rotational driving force from a motor (not shown) is transmitted to the gear portion 231 of the rotating member 23 and then transmitted through a transmission path of the gear portion 232 -the gear portion 241 -the gear 242 -the gear portion 251 -the gear portion 252 -the gear portion 263. Then, the photosensitive drum 1 is driven to rotate.
[0016]
As described above, the power transmission from one side where the drive gear train is disposed across the support panel 21 to the image forming unit where the photosensitive drum 1 is disposed is constituted by the rotating member 25 which is a single power transmission member. As a result, the number of parts constituting the drive unit has been greatly reduced. The rotating member 25 can be made of a slidable resin such as Delrin or Duracon.
[0017]
In order to assemble the driving device, the rotating members 23 and 24 are attached between the support panel 21 and the auxiliary panel by the fixed shafts 27 and 28, and then the rotating member 25 is inserted from the hole of the bearing 211, It is only necessary to insert the shaft 262 and engage the gear portion 263 of the photosensitive drum 1 with the gear portion 252 of the rotating member 25.
[0018]
(Embodiment 2)
Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 4 is a cross-sectional view of the driving apparatus according to the second embodiment.
[0019]
The rotating member 30 is rotatably supported by the fixed shaft 32 supported by the support panel 21 and the auxiliary panel 22, and the rotating member 31 is rotatably supported by the fixed shaft 33 supported by the panels 21 and 22. The Gear portions 311 and 312 and a cylindrical portion 313 are provided on the outer periphery of the rotating member 31 which is an example of the driving force transmitting means, and a bearing 314 is provided on the inner periphery. As in the first embodiment, the clearance between the bearing 314 and the fixed shaft 33 is formed smaller than the clearance between the other inner periphery 315 of the rotating member 31 and the fixed shaft 33, and thus the rotating member 31. Is supported by two bearings 211 and 314 in a stable and freely rotatable manner.
[0020]
An outer diameter D1 of the cylindrical portion 313 is formed larger than an outer diameter D2 of the gear portion 312. With this configuration, the rotating member 31 can be easily assembled by fitting the cylindrical portion 313 to the bearing 211 of the support panel 21 from the auxiliary panel 22 side.
[0021]
In the present embodiment, the rotating member 31 is supported by the fixed shaft 33 so as to be slidable in the axial direction. The slidable rotating member 31 is biased downward by a coil spring 34. In order to ensure the amount necessary for this sliding, the axial length X1 of the cylindrical portion 313 is formed larger than the axial length X2 of the bearing 221 of the panel 22. A gear provided on a rotating shaft of a rotating member of the image forming apparatus such as a developing sleeve of the developing device engages with the gear portion 312.
[0022]
FIG. 4A shows a state in which a rotating member such as a developing device (not shown) is not attached to the image forming apparatus main body. In this state, the rotating member 31 is pushed by the coil spring 34 and is in the lower limit position. When a rotating member (not shown), which is a driven member, is attached to the driving device in the state of FIG. 4A, a gear (not shown) of the rotating member and the gear portion 312 interfere with each other. It moves upward against the force and moves to the state of FIG. When the driving device, that is, the rotating members 30 and 31 are rotated by a motor (not shown) after the rotating member is mounted, the phase relationship between the gear portion 312 and the gear of the rotating member (not shown) is changed, and an engagement between the two is formed. The As a result, the interference state is eliminated, and the rotating member 31 is returned to the state of FIG. 4A by the bias of the coil spring 34, and a drive system for the mounted rotating member is formed.
[0023]
(Embodiment 3)
In Embodiment 3 of the present invention, a rotating member 45, which is an example of a driving force transmitting means constituting the main part of the present invention, is provided on a driving unit of a paper transporting roller that separates and transports the rotating member 45 one by one from the stacked paper. It is applied. 5, FIG. 6 and FIG. 7 show Embodiment 3 of the present invention. FIG. 5 is a sectional view of the entire conveying roller that is supported, FIG. 6 is a side view of the paper pressing member, and FIG. It is sectional drawing.
[0024]
On the panels 40 and 41 of the image forming apparatus main body, a bearing 401 and a bearing 411 formed by injection molding are formed by drawing. A cylindrical portion 452 is rotatably supported on the bearing 401. A gear portion 451 of the rotating member 45 is engaged with a rotating member 46 that transmits a rotational force from a motor (not shown).
[0025]
As shown in FIG. 6, a fan-shaped paper pressing member 44 is rotatably supported on the other panel 41 by a bearing 411 provided on the panel 41. Reference numeral 42 denotes a shaft having a U-shaped cross section formed by bending, and the shaft, the paper feed roller 43, the paper pressing member 44, and the rotating member 45 are separable by the same fixing structure and rotate integrally. Is bound to.
[0026]
This coupling structure will be described with reference to FIGS. 6 and 7 by taking the paper pressing member 44 as an example. The paper pressing member 44 includes a large-diameter paper pressing portion 441 and a coupling arm 443 having a small diameter extending from the core portion 442 and the core portion 442 in the axial direction. A coupling protrusion 444 is formed at the tip of the coupling arm 443. Further, a square hole 445 is formed in the core portion 442. The paper pressing member 44 is attached to the shaft 42 by passing the U-shaped shaft 42 through the hole 445. As shown in FIG. 7, the paper pressing member 44 is firmly coupled to the shaft 42 by the coupling protrusion 444 provided at the tip of the coupling arm 443 entering the coupling hole 421 provided in the shaft 42.
[0027]
As illustrated in FIG. 6, the paper feed roller 43 and the paper pressing member 44 are both substantially semicircular in diameter, and only when the large diameter portion is in contact with the paper, the conveying force or the grip pressing action. There is. The paper feed roller 43 and the paper presser member 44 are formed with a large-diameter portion having a paper feed or paper presser action at the same angular position, and the paper presser member 44 is used only when the paper feed roller 43 transports the paper. It is designed to hold down the lift.
[0028]
In order to assemble this embodiment, the paper feed roller 43 and the paper pressing member 44 are first attached to the shaft 42 in advance, and then the paper pressing member 44 is provided at one end of the shaft 42 and the rotating member 45 is provided at the other end. A process of inserting into the bearings 401 and 411 is employed. Therefore, the thickness of the shaft 42 (the length of the diagonal of the angular axis) needs to be smaller than the diameters of the cylindrical portion 452 and the core portion 442 of the rotating member.
[0029]
Also in this embodiment, only one rotating member 45 is provided to transmit the rotational force from one side of the panel 40 to the other side, and the number of parts is greatly reduced as compared with the conventional driving device. .
[0030]
(Embodiment 4)
A fourth embodiment of the present invention will be described with reference to FIG. This embodiment is applied to a drive unit of a paper conveyance roller.
[0031]
Between the panels 51 and 53 of the image forming apparatus, a shaft 54 to which a paper conveying roller 58 is attached is rotatably supported. The support structure of the shaft 54 is substantially the same as that of the above-described embodiment, and the rotation member 57 as an example of the driving force transmission means and the shaft 54 are integrally coupled by the D cut 541, and the cylindrical portion 572 of the rotation member 57 is formed. A bearing 511 provided on the panel 51 is rotatably supported. The other end of the shaft 54 is rotatably supported by a bearing 58 fixed to the panel 53. Rotational force from a motor (not shown) is transmitted to the gear portion 571 of the rotating member 57 via the rotating members 55 and 56. Reference numeral 59 denotes a rubber paper transport roller, which can be used as a transport roller provided in a transfer paper transport path in the image forming apparatus.
[0032]
(Embodiment 5)
A fifth embodiment of the present invention will be described with reference to FIG. The present embodiment is an example in which a rotating member 61, which is an example of a driving force transmission means that constitutes a main part of the present invention, is used for a driving unit of a fixing roller.
[0033]
In FIG. 9, a rotating member 61 is rotatably supported on the panel 60. Reference numeral 601 denotes a bearing that supports the rotating member 61. A driving force is transmitted to the tooth portion 611 of the rotating member 61. The rotating member 61 is integrally attached to the fixing roller 62. A heat generating lamp 63 is provided in the fixing roller 62. As a material of the rotating member 61, a heat-resistant slidable resin is used. Reference numeral 65 denotes a locking ring. A driving force is transmitted from a motor and a power transmission system (not shown) to the gear portion 611 so that the rotating member 61 and the fixing roller 62 rotate integrally.
[0034]
As shown in FIG. 9, the transmission system of the driving force to the fixing roller is not limited to a configuration in which the fixing roller 62 is directly fixed to the rotating member 61. And this gear can be configured to be driven by the driving force transmission means.
[0035]
【The invention's effect】
The transmission mechanism that transmits power from the drive unit side of the panel that separates the drive unit and the image forming unit to the image forming unit is greatly simplified, and the number of parts of the drive device of this part is greatly reduced, The assembly of the drive unit is facilitated, and the manufacturing cost of the image forming apparatus is reduced.
[Brief description of the drawings]
FIG. 1 is a diagram showing a conventional driving apparatus.
FIG. 2 is a diagram schematically showing an image forming apparatus in which the present invention is used.
FIG. 3 is a cross-sectional view of the driving apparatus according to the first embodiment.
FIG. 4 is a cross-sectional view of a driving apparatus according to a second embodiment.
FIG. 5 is a cross-sectional view of a driving apparatus according to a third embodiment.
6 is a side view of a paper pressing member according to Embodiment 3. FIG.
7 is a cross-sectional view of a coupling portion between a driven shaft and a paper pressing member in Embodiment 3. FIG.
FIG. 8 is a cross-sectional view of a driving apparatus according to a fourth embodiment.
FIG. 9 is a sectional view of a driving apparatus according to a fifth embodiment.
[Explanation of symbols]
21, 40, 51, 60 Support panel (panel)
22 Auxiliary panels 25, 31, 45, 57, 61 Rotating members (driving force transmission means)
42,54 shaft 211,511,401,601 bearing 251,311,451,571 gear part 253,313,452,572,612 cylindrical part

Claims (9)

Support panel (21),
Auxiliary panel (22),
Fixed shafts (29, 33) fixed to the auxiliary panel; and
Driving force transmission means (25, 31),
The driving force transmission means (25, 31)
Gear portions (251, 311) positioned between the support panel (21) and the auxiliary panel (22),
Gear portions (252, 312) projecting on the opposite side of the surface of the support panel (21) facing the auxiliary panel,
Cylindrical portions (253, 313) rotatably supported by bearings (211) provided on the support panel (21);
Bearings (254, 314) rotatably supported by the fixed shafts (29, 33),
Have
The driving force transmission means (25, 31) is constituted by an integral part made of a slidable resin having the protruding gear part (252, 312) on the opposite side and the cylindrical part (253, 313). In addition, the outer diameter of the cylindrical portion (253, 313) is larger than the outer diameter of the protruding gear portion (252, 312) on the opposite side . Driving device of an image forming apparatus according to claim 1, characterized in that the axial length of said bearing (211) was more than the thickness of the support panel (21). 3. The driving device for an image forming apparatus according to claim 1, wherein the driving force transmitting means (25, 31) is supported by the fixed shaft (29, 33) so as to be slidable in the axial direction thereof. . The length in the axial direction of the fixed shaft (29, 33) of the cylindrical portion (253, 313) is longer than the length in the axial direction of the bearing (211). 4. The drive device for an image forming apparatus according to claim 1. 5. The drive device for an image forming apparatus according to claim 4, further comprising a spring (34) for urging the drive force transmission means (25, 31) in the axial direction. 6. The driving device for an image forming apparatus according to claim 1, wherein a developing device is connected to the driving force transmitting means (25, 31). 6. The driving device for an image forming apparatus according to claim 1, wherein a cleaning device is connected to the driving force transmitting means (25, 31). 6. The driving device for an image forming apparatus according to claim 1, wherein a photosensitive member driving device is connected to the driving force transmitting means (25, 31). 6. The driving device for an image forming apparatus according to claim 1, wherein a fixing device driving device is connected to the driving force transmitting means (25, 31).

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