JP2002156020A - Driving mechanism of rotor and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a driving mechanism of a rotor capable of preventing backlash of the rotor in a comparatively simple mechanism to stabilize the rotation and an image forming apparatus having it. SOLUTION: This driving mechanism 110 of a rotor has the rotor 101, a driving source 5 for driving the rotor 101, a first transmitting means 34, 36, 37, 38 for transmitting the driving force of the driving source 5 to the rotor 101, and a second transmitting means 39, 40 for transmitting the driving force of the driving source 5 to the rotor 101 through a different route from the first transmitting means 34, 36, 37, 38. The second transmitting means 39, 40 apply load to the drive of the rotor 101 using the first transmitting means 34, 36, 37, 38. The image forming apparatus has the above driving mechanism.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driving mechanism for a rotating body such as an image carrier and an image forming apparatus having the same.

[0002]

2. Description of the Related Art Image forming apparatuses such as printers, electrophotographic copying machines, and facsimile machines are provided with a rotating body such as an image carrier. A motor is usually used as a driving source of the rotating body, but a gear or a timing belt is generally used as a means for transmitting the rotating driving force of the motor to the rotating body. A configuration using a gear as such means is disclosed in, for example, Japanese Patent Application Laid-Open No. H11-7205.

A configuration using a timing belt as such means is well known in various publications and the like, and an example thereof is shown in FIG. In this example, a photoconductor drum (hereinafter, referred to as a “photoconductor”) 101 as an image carrier is provided as a rotating body. The photoreceptor 101 is integrated with the shaft 1 by a pin 2 and rotates about the shaft 1. The axis 1 is the photoconductor 101
Are rotatably supported by a support plate 3 via bearings 4 at both ends. The shaft 1 also has a motor 5 as a driving source.
Are also rotatably supported by bearings 7 on a motor mounting plate 6 fixed to the outer surface of the support plate 3 for supporting the motor.

A shaft 8 of the motor 5 is located between the support plate 3 and the motor mounting plate 6, and a drive pulley 9 is fixed to the shaft 8. A driven pulley 11 is fixed between the support plate 3 and the motor mounting plate 6 of the shaft 1 by a pin 10, and a timing belt 1 is provided between the driven pulley 11 and the driving pulley 9.
2 is wound. A flywheel 14 is fixed to the shaft 1 on the opposite side of the driven pulley 11 across the motor mounting plate 6 by a pin 13. The photoconductor 101 is driven to rotate by the motor 5. At this time, the flywheel 14 is driven to rotate integrally with the photoconductor 101, so that the rotation of the photoconductor 101 is stabilized.

[0005]

However, if a gear or a timing belt is used as a means for transmitting the rotational driving force of the motor to the rotating body, backlash occurs and the rotation speed of the rotating body fluctuates. In addition, there is a problem in that high-quality image formation is hindered. In order to prevent such a problem, there is a configuration using a flywheel as shown in FIG. 5, but the flywheel rotates by preventing the speed fluctuation of the rotating body by the inertial energy of the rotation. Therefore, in order to increase the inertial energy, it is necessary to increase its radius and mass. Therefore, if the flywheel alone is used to prevent backlash and fluctuations in the rotational speed of the rotating body, the size of the device will increase, and the weight of the flywheel itself will increase. There is a problem that it is necessary to increase the rigidity of the structure.

Means for stabilizing the rotation of the rotating body include, besides the flywheel, the above-mentioned JP-A-11-7205.
As disclosed in Japanese Unexamined Patent Publication (Kokai) No. H10-163, there is known a configuration in which a brake material such as a roller that comes into contact with a gear or the like disposed on the surface of a rotating body or a shaft of the rotating body is provided. When the contact is made, the driving load of the rotating body increases, so that it is necessary to increase the size of the driving source of the rotating body, that is, the motor, and it is necessary to adjust the pressure when mounting the brake material,
In addition, a change with time of the brake material, for example, a change in the braking effect due to wear becomes a problem.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a driving mechanism for a rotating body which stably rotates the rotating body by preventing backlash or the like of the rotating body with a relatively simple mechanism, and an image forming apparatus having the same. .

[0008]

According to a first aspect of the present invention, there is provided a rotating body, a driving source for driving the rotating body, and a driving force of the driving source. A first transmission means for transmitting to the body, and a second transmission means for transmitting the driving force of the driving source to the rotating body through a different path from the first transmission means; The second transmitting means is a driving mechanism of the rotating body that applies a load to the driving of the rotating body by the first transmitting means.

According to a second aspect of the present invention, in the driving mechanism for a rotating body according to the first aspect, the angular speed of rotation that the first transmitting means intends to give to the rotating body is as follows. It is characterized by being greater than the angular velocity of rotation to be given to the body.

[0010] The invention according to claim 3 provides claims 1 to 3.
In the driving mechanism for a rotating body according to any one of the above,
Is characterized by a gear mechanism.

[0011] The invention according to claim 4 is the invention according to claims 1 to 4.
The driving mechanism for a rotating body according to any one of
Is characterized by a roller mechanism.

According to a fifth aspect of the present invention, in the driving mechanism of the rotating body according to the fourth aspect, the roller mechanism has a roller, and the roller has a transmission member for transmitting a driving force to the roller and the roller. Are elastically in contact with the transmitted member transmitting the driving force.

The invention according to claim 6 is the invention according to claims 1 to 5
In the driving mechanism for a rotating body according to any one of the above,
The torque of the transmitting means to the rotating body is larger than the torque of the second transmitting means to the rotating body.

The invention according to claim 7 is the invention according to claims 1 to 6
The driving mechanism for a rotating body according to any one of the above, further comprising a rotating member that rotates integrally with the rotating body, wherein the first transmitting means and the second transmitting means transmit a driving force of the driving source. The rotation member is driven to rotate by transmitting the rotation member to the rotation member.

According to an eighth aspect of the present invention, in the driving mechanism for a rotating body according to the seventh aspect, the rotating member is integrated with a rotating shaft of the rotating body and rotates about the rotating shaft. I do.

The invention according to claim 9 is the invention according to claim 7 or 8.
In the driving mechanism for a rotating body described above, the rotating member is a flywheel.

According to a tenth aspect of the present invention, in the driving mechanism for a rotating body according to any one of the first to ninth aspects, the rotating body is an image carrier.

According to an eleventh aspect of the present invention, there is provided an image forming apparatus having the rotary body driving mechanism according to any one of the first to tenth aspects.

[0019]

FIG. 1 shows an image forming apparatus to which the present invention is applied. The image forming apparatus 100 includes a photoconductor drum (hereinafter, referred to as a “photoconductor”) 10 as an image carrier that is a rotating body that is driven to rotate about an axis 1 as a rotation axis in the direction of arrow A.
1, a charging device 102 as a charging unit for charging the photoconductor 101, an exposure device (not shown) as an exposure unit for emitting a laser beam 103 for forming a latent image on the charged photoconductor 101 and performing optical scanning; A developing device 104 as a developing device for developing the latent image on the photoconductor 101 after the exposure, a transfer device 105 as a transferring device for transferring the toner image on the photoconductor 101 obtained by the development onto the paper P; A cleaning device 106 as a cleaning unit that cleans the surface of the photoconductor 101 afterward, a non-illustrated static elimination device 105 as a static elimination device that performs static elimination before performing charging by the charging device 102, and a photoconductor 101 and a transfer device 104 A registration roller 107 that conveys the sheet P at a predetermined timing toward the opposing portion; and a guide unit that guides the sheet P on which the toner image has been transferred. And the guide plate 108, the guide plate 10
And a fixing device 109 as a fixing unit for fixing the paper P guided by the fixing device 8.

The charging roller 1 provided in the charging device 102
02a, developing roller 104 provided in developing device 104
a, a transfer roller 105a provided in the transfer device 105,
Fur brush 10 provided in cleaning device 106
6a rotates in the B direction, the C direction, the D direction, and the E direction, respectively. The B direction, the C direction, and the D direction are all
The direction E is the direction of movement in the same direction as the direction A at the position facing the photosensitive member 101, and the direction E is the direction of movement in the direction opposite to the direction A at the position facing the photosensitive member 101.

The cleaning device 106 removes toner and fine paper dust remaining on the surface of the photosensitive member 101 by the fur brush 106a. The fixing device 109 includes a heating roller 10 that is driven to rotate in the F direction.
9a and a pressure roller 10 pressed against and driven by the pressure roller 9a
9b, the toner image on the sheet P is fused and fixed to the sheet P by heating by a heating source (not shown) built in the heating roller 109a and pressing by the pressing roller 109b. .

As shown in FIGS. 2, 3, and 4, the image forming apparatus 100 includes a rotating body driving mechanism 110 for keeping the rotation of the photosensitive member 101 constant with high accuracy. In the driving mechanism 110 for the rotating body, the same configurations as those of the conventional mechanism shown in FIG. 5 are appropriately omitted from illustration or the same reference numerals, and the description is omitted. The photoreceptor 101 is integrated with the shaft 1 by a pin 2 and rotates about the shaft 1.
An iron flywheel 32 as a rotating member is fixed to the shaft 1 by a pin 31 between a support plate 3 and a motor mounting plate 6 supporting a motor 5 which is a DC brushless motor as a driving source. . Therefore, the flywheel 32 rotates about the shaft 1 integrally with the photoconductor 101.

As shown in FIG. 3, a concave portion 33 is formed on the side surface of the flywheel 32 on the motor mounting plate 6 side, and a gear 34 is fitted on a side edge of the concave portion 33 on the center side. Fixed. A stud 35 is fixed to the inner side surface of the motor mounting plate 6 so that a tip portion thereof enters the concave portion 33. The stud 35 supports a small-diameter gear 36 that meshes with the gear 34 and a gear 37 that is larger than the gear 36 and that is larger than the gear 36 and that is disposed closer to the motor mounting plate 6 than the gear 36. On the shaft 8 of the motor 5, a small-diameter gear 38 that meshes with the gear 37 and a roller 39 that is a friction wheel disposed closer to the support plate 3 than the gear 38 are fixed. The roller 39 is separated from the outer peripheral surface of the flywheel 32.

As shown in FIG. 2 or 4, an idle roller 40 as a roller serving as a friction wheel is provided so as to contact the outer peripheral surfaces of the roller 39 and the flywheel 32. The idle roller 40 has its shaft 41 rotatably supported by a roller bracket 42. The roller bracket 42 is elastically supported on the motor mounting plate 6 by a pressing spring 43 as an urging member. The urging force of the pressing spring 43 causes the idle roller 40 to be elastically applied to the outer peripheral surfaces of the roller 39 and the flywheel 32. Are in contact.
The roller 39 is a transmitting member that transmits a driving force to the idle roller 40, and the flywheel 32 is a transmitted member that the idle roller 40 transmits the driving force.

As shown in FIG. 4, when the motor 5 operates and the gear 38 and the roller 39 are driven to rotate in the direction indicated by the arrow G, the motor 5 is driven by the gear 38, the gear The photoconductor 101 is rotationally driven by being transmitted to the flywheel 32 via the gear 37, the gear 36, and the gear 34. At this time, the gears 37 and 36 rotate in the direction indicated by arrow H, and the gear 34 and the flywheel 32 rotate in the direction indicated by arrow I. Note that the I direction is the same direction as the A direction which is the rotation direction of the photoconductor 101 in FIG. The gear 38, the gear 37, the gear 36, and the gear 34 are first gears for transmitting the rotational driving force of the motor 5 to the photoconductor 101.
Of the transmission means.

On the other hand, when the motor 5 operates and the gear 38 and the roller 39 are driven to rotate in the direction indicated by the arrow G, the motor 5 applies the rotation driving force to the flywheel 32 via the roller 39 and the idle roller 40. The photoconductor 101 is driven to rotate by being transmitted. At this time, idle roller 4
0 rotates in the direction indicated by arrow J. The roller 39 and the idle roller 40 constitute a roller mechanism that constitutes second transmission means for transmitting the rotational driving force of the motor 5 to the photosensitive member 101 through a path different from that of the first transmission means.

Thus, the rotational driving force of the motor 5 is 2
The photoconductor 1 is transmitted to the flywheel 32 through
However, the roller mechanism applies a load to the drive of the photoconductor 101 by the gear mechanism. Specifically, the angular velocity of rotation that the gear mechanism intends to give to the photoconductor 101 is determined by the roller mechanism
01 is set to be larger than the rotational angular velocity to be given, and the torque of the gear mechanism on the photoconductor 101 is set to be larger than the torque of the roller mechanism on the photoconductor 101.

Therefore, the photoreceptor 101 rotates at the angular velocity of rotation given to the flywheel 32 by the gear mechanism. Here, the reason why the torque on the photosensitive member 101 by the gear mechanism is larger than the torque on the photosensitive member 101 by the roller mechanism is that the roller 39 and the idle roller 40 in the roller mechanism.
Is a friction wheel, and a slip occurs between the rollers and between the idle roller 40 and the flywheel 32 in accordance with the angular velocity of rotation given to the flywheel 32 by the gear mechanism. The roller mechanism rotates the motor 5 even if the rollers 39 and 40 wear over time because the idle roller 40 elastically contacts the rollers 39 and the flywheel 32 by the urging force of the pressing spring 43. The photoconductor 101 can be driven to rotate favorably by the force.

Further, the photosensitive member 1 is provided by the roller mechanism.
01 backlash is prevented. The diameter of the gear 38, the gear 37, the gear 36, the gear 34, the flywheel 32, the roller 39, and the idle roller 40 is determined by the angular velocity of rotation that the gear mechanism intends to give to the photosensitive member 101, and the roller mechanism is given to the photosensitive member 101 by the roller mechanism. It is set to be higher than the angular velocity of the rotation to be performed. The rotation speed, diameter, and mass of the flywheel 32 are set so that the moment of inertia generated thereby can rotate the photoconductor 101 stably.

Since the image forming apparatus 100 has the above-described configuration, the photosensitive member 101 charged in the charging step by the charging device 102 is rotated in the direction of arrow A to form a latent image in the exposure step by the laser beam 103, and a developing device. 10
After the development step by Step 4, the transfer step by the transfer device 105, the cleaning step by the cleaning device 106, and the charge removal step by the charge removal device, the process returns to the charging step. The toner image transferred onto the sheet P in the transfer process is
The image is fixed on the paper P by the transfer process at 09.
The sheet P on which the toner image has been fixed is discharged outside the apparatus.

In these image forming steps, the moment of inertia of rotation by the flywheel 32 is
Since the rotation of the photosensitive member 101 is kept constant with high accuracy and the rotation of the photosensitive member 101 is stabilized, high-quality image formation can be performed without causing image displacement and blurring. Further, since the photoreceptor 101 is rotationally driven by a gear mechanism and a roller mechanism that attempts to rotate at a lower angular velocity than the motor 5, the rotation of the photoreceptor 101 is kept at a high precision and constant by the gear mechanism. At the same time, backlash of the photoconductor 101 is prevented. Even if the rotational load of the photoconductor 101 increases for some reason, the rotation of the photoconductor 101 is kept substantially constant by the roller mechanism assisting the gear mechanism.

Although the embodiment of the present invention has been described above, the rotating body is not limited to the photosensitive drum, but a belt-shaped photosensitive body is wound around, and a driving roller for driving the photosensitive body is provided. It is possible to apply a roller that is to be performed. The first transmission means is not a gear mechanism but a
The timing belt mechanism shown in FIG.
Instead of a flywheel, a friction wheel can be used as the rotating member.

[0033]

The present invention provides a rotating body, a driving source for rotating the rotating body, a first transmitting means for transmitting a driving force of the driving source to the rotating body, And a second transmitting means for transmitting the driving force of the driving source to the rotating body through a different path from the first transmitting means, wherein the second transmitting means is provided by the first transmitting means. Since the driving mechanism of the rotating body that applies a load to the drive of the rotating body is provided, it is possible to provide a driving mechanism of the rotating body that can keep the rotation of the rotating body constant with high accuracy.

If the angular velocity of rotation that the first transmission means intends to give to the rotating body is greater than the angular velocity of rotation that the second transmitting means intends to give to the rotating body, the difference in angular velocity It is possible to provide a rotating body driving mechanism capable of applying a load to the driving of the rotating body by the first transmitting means by the second transmitting means.

If the first transmission means is a gear mechanism, it is possible to provide a driving mechanism for the rotating body capable of reliably transmitting the torque of the driving source to the rotating body.

If the second transmission means is a roller mechanism, it is possible to cause slippage between the members, and by performing rotation transmission in accordance with the rotation transmission force of the first transmission means, the drive is performed. This prevents an excessive load from being applied to the mechanism and prevents the mechanism from being damaged. Further, even if the first transmission means causes a backlash in the mechanism, the backlash is prevented, and the rotation of the rotating body is increased. It is possible to provide a highly safe rotating body drive mechanism that can be maintained at a constant accuracy.

The roller mechanism has a roller, and the roller elastically abuts a transmitting member for transmitting a driving force to the roller and a transmitted member for transmitting the driving force to the roller. Thus, it is possible to provide a driving mechanism for a rotating body that can transmit the driving force satisfactorily even if the rollers, the transmission member, and the transmitted member wear over time.

Assuming that the torque of the first transmitting means to the rotating body is larger than the torque of the second transmitting means to the rotating body, the rotation is transmitted in accordance with the rotation transmitting force of the first transmitting means. In addition, it is possible to provide a highly safe rotating body driving mechanism capable of preventing an excessive load from being applied to the driving mechanism and maintaining the rotation of the rotating body with high accuracy and constant without causing breakage.

A rotating member that rotates integrally with the rotating body,
If the first transmission means and the second transmission means rotate the rotating body by transmitting the driving force of the driving source to the rotating member, the driving force is indirectly transmitted to the rotating body. Thus, it is possible to provide a rotating body driving mechanism capable of reducing the load on the rotating body due to the first and second transmission means and preventing deterioration of the rotating body with time.

If the rotating member is integrated with the rotating shaft of the rotating body and rotates about the rotating shaft, the supporting mechanism of the rotating member can be simplified and the rotating body can be prevented from being enlarged. A mechanism can be provided.

If the rotating member is a flywheel, it is possible to provide a driving mechanism for the rotating body that can keep the rotation of the rotating body constant with higher accuracy by the moment of inertia.

Assuming that the rotating body is an image carrier, by keeping the rotation of the rotating body constant with high accuracy and stability,
It is possible to provide a rotating body drive mechanism that can contribute to high-quality image formation.

Since the present invention resides in an image forming apparatus having such a rotating body driving mechanism, the rotation of the rotating body can be stably maintained with high accuracy and constant, and high quality image formation can be performed. Thus, an image forming apparatus with high user reliability can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating an image forming apparatus to which the present invention is applied.

FIG. 2 is a side view showing a driving mechanism for a rotating body to which the present invention is applied, provided in the image forming apparatus shown in FIG.

FIG. 3 is an enlarged side sectional view of a main part of a driving mechanism of the rotating body shown in FIG. 2;

FIG. 4 is a front view showing a manner of driving a gear mechanism, a roller mechanism, and a rotating member.

FIG. 5 is a side sectional view showing a conventional rotating body driving mechanism.

[Explanation of symbols]

 Reference Signs List 5 drive source 32 rotating member, flywheel, transmitted member 34, 36, 37, 38 first transmission means, gear mechanism 39 transmission member 39, 40 second transmission means, roller mechanism 100 image forming apparatus 101 rotating body, Image carrier 110 Driving mechanism of rotating body

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F16H 13/04 F16H 13/04 C 37/02 37/02 A 57/12 57/12 A G03G 21/00 350 G03G 21/00 350 F-term (reference) 2H035 CA07 CB01 CG03 3J009 DA11 EA05 EA11 EA21 EA32 ED01 FA17 FA18 3J051 AA01 BA03 BB01 BD01 BE03 EA02 EB03 ED15 FA08 3J103 AA02 FA18 GA52 FA43 GA60

Claims (11)

[Claims] 1. A rotating body, a driving source for rotationally driving the rotating body, a first transmitting means for transmitting a driving force of the driving source to the rotating body, and a first transmitting means. And a second transmitting means for transmitting the driving force of the driving source to the rotating body through a different path from the driving means, wherein the second transmitting means applies a load to the driving of the rotating body by the first transmitting means. A drive mechanism for a rotating body characterized by applying a force. 2. The rotating body driving mechanism according to claim 1, wherein the angular velocity of rotation that the first transmitting means intends to apply to the rotating body is such that the second transmitting means attempts to impart the rotating body to the rotating body. A driving mechanism for a rotating body, wherein the driving mechanism is higher than the angular velocity of rotation. 3. The driving mechanism for a rotating body according to claim 1, wherein the first transmission means is a gear mechanism. 4. The driving mechanism for a rotating body according to claim 1, wherein the second transmission means is a roller mechanism. 5. A driving mechanism for a rotating body according to claim 4, wherein said roller mechanism has a roller, and said roller comprises:
A driving mechanism for a rotating body, wherein a transmitting member for transmitting a driving force to the roller and a transmitted member for transmitting the driving force to the roller are elastically in contact with each other. 6. A driving mechanism for a rotating body according to claim 1, wherein a torque of said first transmitting means on said rotating body is smaller than a torque of said second transmitting means on said rotating body. A driving mechanism for a rotating body characterized by being large. 7. A driving mechanism for a rotating body according to claim 1, further comprising a rotating member that rotates integrally with said rotating body, wherein said first transmitting means and said second transmitting means are provided. Is a driving mechanism of the rotating body, wherein the rotating body is rotationally driven by transmitting a driving force of the driving source to the rotating member. 8. A driving mechanism for a rotating body according to claim 7, wherein said rotating member is integrated with a rotating shaft of said rotating body and rotates about said rotating shaft. . 9. A driving mechanism for a rotating body according to claim 7, wherein said rotating member is a flywheel. 10. A driving mechanism for a rotating body according to claim 1, wherein said rotating body is an image carrier. 11. An image forming apparatus having the driving mechanism for a rotating body according to claim 1.