JPH0932897A - Drive transmission device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a belt from becoming detached from a pulley without increasing cost by disposing a restricting member for preventing the belt from going up outside the belt at a position where the pulley begins engaging with a timing belt. SOLUTION: This device has a pressing roller 35 of a restricting member outside the belt 30 at a position G where a driven pulley 25 begins engaging with a timing belt 30. The pressing roller 35 is rotatably attached to one end of a rotating lever 31 and the rotating lever 31 is rotatably supported by a support shaft 31a and urged by an urging spring 32 to press the pressing roller 35 on the belt 30. A motor of a large size or increased support strength is not necessary for pressing a strong force on the belt 30, thereby preventing the belt 30 from becoming detached from the pulley 25 without increasing cost.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive transmission device provided in a printer, a copying machine, a facsimile and the like.
Among them, in particular, it relates to a drive transmission device that spans a timing belt between pulleys to transmit the driving force of a motor.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 6, in a drive transmission device of this type provided in a laser printer, a timing belt 1 is arranged between a drive pulley 2 and driven pulleys 3 and 4. There is something. Then, at the time of recording, a motor (not shown) is driven to rotate the drive pulley 2 to rotate the timing belt 1 in the direction of arrow A in the figure, so that the motor is rotated, for example, a cleaning brush or a cleaning brush around the photosensitive member.
It was transmitted to the registration rollers.

By the way, in such a drive transmission device,
Make it easy for the timing belt and pulley to mesh with each other.
For example, as shown in FIG.
b is formed by a slope.

However, if the pulleys and the timing belt have deformation due to heat and variations in component accuracy, due to the influence thereof, the position where the pulley and the timing belt start meshing during drive transmission, for example, as shown in FIG. There is a case where the belt does not mesh with G and floats up to come off the pulley. In the case of a laser printer, if the belt comes off like that, for example, rotation irregularity occurs on the photoconductor and the image quality deteriorates.

Therefore, conventionally, in order to prevent the belt from coming off, for example, as shown in FIG. 6, a rotary lever 6 is provided on the outer side of the timing belt 1 between the pulleys 2 and 3 as a support shaft 6a.
Rotatably provided around the center of the rotation lever 6, a pressing roller 7 is attached to one end of the rotating lever 6, and an urging spring 8 is attached to the other end, and the urging force of the urging spring 8 pushes the pressing roller 7 against the timing belt 1. The belt 1 was pressed against the lifting of the belt 1 from the pulley 3.

[0006]

However, in such a conventional one, in order to surely press the rising of the timing belt 1, the pressing roller 7 is pressed by a corresponding biasing force.
It is necessary to strongly press against the timing belt 1. Then, the strong pressing force becomes a large load for driving the belt, so that it is necessary to increase the driving torque by using, for example, a large motor. In addition, it is necessary to increase the overall support strength by forming the support shafts 2a to 4a of the pulleys 2 to 4 with strong rigidity according to the strong pressing force. As a result, conventionally, there has been a problem that the cost becomes high.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to reliably prevent the timing belt from coming off the pulley in the drive transmission device as described above, without causing such an increase in cost.

[0008]

Therefore, the invention described in claim 1 is, for example, as in the following embodiment.
In a drive transmission device that transmits a driving force by a timing belt 30 such as the drive pulley 23 and the driven pulleys 24 and 25, the timing is at a position G where the pulley and the timing belt 30 start meshing with each other. It is characterized in that a regulation member such as a pressing roller 35, a fixing member 40, a regulation roller 45, and a toothed regulation roller 50 that presses the lifting of the timing belt 30 is arranged outside the belt 30.

Then, at the position G where the pulley and the timing belt 30 start to mesh with each other during drive transmission,
The lifting of the timing belt 30 is restricted by the restriction member.

According to a second aspect of the present invention, as in the embodiment shown in FIG. 1 below, in the drive transmission device according to the first aspect, a rotating body such as a pressing roller 35 is used as the regulating member. It is characterized in that the rotating body is biased and pressed against the timing belt 30.

Then, at the position G where the pulley and the timing belt 30 start to mesh with each other during drive transmission,
The rotating body suppresses the lifting of the timing belt 30.

According to a third aspect of the present invention, for example, as in the embodiment shown in FIG. 3 below, in the drive transmission device according to the first aspect, a fixing member 40 is used as the regulating member, and the pulley is It is characterized in that the fixing member 40 regulates the lifting of the timing belt 30 beyond the meshing amount of the timing belt 30.

Then, at the position G where the pulley and the timing belt 30 start to mesh with each other during drive transmission,
The fixing member 40 regulates the lifting of the timing belt 30.

According to a fourth aspect of the present invention, for example, as in the embodiment shown in FIG. 4 below, in the drive transmission device according to the first aspect, a rotating body such as a regulating roller 45 is used as the regulating member. The rotation body is rotatably provided on the fixed shaft 44, and the rotation body regulates the lifting of the timing belt 30 beyond the meshing amount of the pulley and the timing belt 30. To do.

Then, at the position G where the pulley and the timing belt 30 start to mesh with each other during the transmission of the drive, the rotating body regulates the lifting of the timing belt 30.

According to a fifth aspect of the present invention, for example, as in the embodiment shown in FIG. 5 below, in the drive transmission device according to the fourth aspect, the timing belt 30 is provided with teeth on the outer periphery, and the timing belt 30 has teeth. A toothed rotating body such as the toothed regulation roller 50 is used as the rotating body, and the toothed rotating body is meshed with the timing belt 30.

Then, at the position G where the pulley and the timing belt 30 start to mesh with each other during drive transmission,
The toothed rotating body regulates the lifting of the timing belt 30.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 is a schematic configuration diagram of a laser printer including the drive transmission device according to the first and second aspects.

Reference numeral 10 in the figure denotes the apparatus main body. A drum-shaped photoconductor 11 is provided in the center of the apparatus main body 10, and a charging device 12, a developing device 13, a transfer roller 14, and a cleaning device 15 are sequentially arranged around the photoconductor 11 in a driving direction indicated by an arrow. Prepare A fixing device 16 is provided on the left side of the cleaning device 15 in the figure. Further, an optical writing device 17 is provided on the upper side of the charging device 12. Then, a paper feed cassette 18 is detachably provided on the right side of the apparatus body 10 in the figure.

Therefore, at the time of recording, the paper P is unwound from the paper feed cassette 18 in the arrow B direction, and is fed to the lower side of the photoconductor 11 by the registration roller 19 at a timing. The photoconductor 11 rotates in the clockwise direction shown by the arrow, at which time the surface is uniformly charged by the charging device 12, and laser light is emitted from the optical writing device 17 to form an electrostatic latent image on the surface. To do. When the latent image passes through the position of the developing device 13, the developing device 13 attaches toner to form a visible image. Further, this visible image is transferred to the paper P below the photoconductor 11 by the transfer roller 14. After the transfer, the fixing device 16 fixes the visible image on the paper P. After the image is fixed, the paper P is conveyed in the arrow C direction and discharged onto the paper discharge unit 20. On the other hand, after the transfer, the surface of the photoconductor 11 is cleaned by the cleaning device 1.
The cleaning brush 15a of No. 5 is used for cleaning.

By the way, the apparatus main body 10 is provided with the above-described photoconductor 11 and the developing device 13, cleaning device 15 and the like around the photoconductor 11 between the opposing side plates (not shown), and drives them outside one of the side plates. A transmission device is provided.

This drive transmission device, as shown in FIG.
A timing belt 30 is stretched between the drive pulley 23 and the driven pulleys 24 and 25. Then, the support shaft 2 is provided outside the timing belt 30 between the drive pulley 23 and the driven pulley 24.
A rotation lever 26 is provided that is rotatably supported by 6a. Then, the tension roller 27 is attached to one end of the rotating lever 26, and the biasing spring 28 is attached to the other end. Then
The urging spring 28 constantly urges the rotating lever 26 to urge the tension roller 27 against the timing belt 30 to apply a constant tension to the entire timing belt 30.

Further, in this drive transmission device, the position G where the driven pulley 25 and the timing belt 30 start to mesh with each other.
Then, the pressing roller 35 as a regulating member is provided on the outer side of the belt 30. The pressing roller 35 is rotatably attached to one end of the rotating lever 31. The rotation lever 31 is a support shaft 31.
It is rotatably supported by a, and a biasing spring 32 is attached to the other end. Then, the urging spring 32 urges the rotation lever 31 to press the pressing roller 35 against the timing belt 30.

In the drive transmission device described above, during recording, the motor (not shown) is driven to rotate the drive pulley 23 and rotate the timing belt 30 in the direction of the arrow in FIG. 1 to rotate the motor. For example, it is transmitted to the photoconductor 11, the transfer roller 14, the cleaning brush 15a, the registration roller 19, and the like.

During this drive transmission, the driven pulley 2
5, the lifting of the timing belt 30 is pressed by the pressing roller 35 at the position G where the timing belt 30 starts to be meshed, and the timing belt 30 is prevented from being disengaged from the driven pulley 25.

By the way, in the above-described embodiment, the pressing roller 35 of the restricting member is directly pressed against the timing belt 30 to restrict the disengagement thereof. However, as shown in the following embodiments, the restricting member is provided with the timing belt. It is advisable to adopt a configuration in which the detachment is regulated without being pressed against 30.

For example, as shown in FIG. 3, a fixing member 40, which is a regulating member, is fixed at a position separated from the timing belt 30 by a distance d outside the position G where the meshing is started. The distance d is smaller than the meshing amount between the driven pulley 25 and the timing belt 30. Further, as the fixing member 40, for example, a low friction member having a relatively small friction coefficient such as polyacetal resin may be used.

In this embodiment, when the timing belt 30 is lifted at the position G where the driven pulley 25 starts to mesh with each other during transmission of the drive, the meshing amount of the driven pulley 25 and the timing belt 30 is larger than the meshed amount. The fixing member 40 regulates the lifting of the belt 30. Thus, the timing belt 30 is prevented from coming off the driven pulley 25.

By the way, in the embodiment shown in FIG.
Although the fixing member 40 is used as the restricting member, it is more preferable to use a rotating body as the restricting member as shown in the following embodiment.

In this case, as the rotating body, for example, FIG.
A regulation roller 45 as shown in is used. The regulation roller 45 is
Similar to the above, outside the position G where the meshing starts,
A fixed shaft 44 is rotatably supported at a position separated from the timing belt 30 by the distance d.

Further, in this embodiment, when the timing belt 30 is lifted at the position G where the driven pulley 25 starts meshing during drive transmission, the lifting of the timing belt 30 beyond the meshing amount is restricted. It regulates with roller 45. Then, the timing belt 30
Of the driven pulley 25 is prevented.

By the way, in the above-described embodiment, the timing belt 30 is a single-sided toothed belt having teeth on its inner circumference. However, as in the embodiment shown in FIG. It is also possible to use a double-sided toothed belt having teeth on the outer circumference.

Further, a toothed regulation roller 50 having teeth on its outer periphery is used as the rotating body of the regulation member. Toothed regulation roller 50
Is rotatably supported by a fixed shaft 51 at a position separated from the timing belt 30 by the distance d outside the position G where the meshing is started. Then, at the separated position, the outer peripheral teeth mesh with the outer teeth 30 a of the timing belt 30. The distance d is smaller than the amount of meshing between the teeth of the driven pulley 25 and the inner teeth 30b of the timing belt 30.

However, in this embodiment, when the timing belt 30 is lifted at the position G where the driven pulley 25 starts meshing with the driven pulley 25 during drive transmission, the timing belt 30 is lifted by more than the meshing amount. It is regulated by the tooth regulation roller 50. Thus, the timing belt 30 is prevented from coming off the driven pulley 25.

[0035]

Therefore, according to the first and second aspects of the present invention, at the position where the pulley and the timing belt start to mesh with each other, the lifting of the timing belt is suppressed by the regulating member arranged outside the belt. Since it is configured to regulate the disengagement from the pulley, it is not necessary to use a large motor or increase the support strength because a strong pressing force is applied to the timing belt as in the past, which results in high cost. It is possible to reliably prevent the timing belt from being detached from the pulley without inducing.

Further, according to the invention as defined in claims 3 to 5, the belt is restricted only when the belt is lifted more than the meshing amount of the pulley and the timing belt. Therefore, when the lifting is restricted, the belt is restricted. The load on the drive can be reduced.

In addition, in the case of the invention described in claims 4 and 5, in addition, since the lifting of the timing belt is restricted by the rotating body or the toothed rotating body, the belt is contacted by friction when restricting the lifting. The load given to the drive can be almost eliminated.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a drive transmission device that is an embodiment of the invention described in claims 1 and 2. FIG.

FIG. 2 is a schematic configuration diagram of a laser printer including the drive transmission device.

FIG. 3 is an explanatory diagram showing a positional relationship between a timing belt meshing with a driven pulley and a fixing member that restricts the lifting of the timing belt, in the drive transmission device according to the third embodiment of the invention.

FIG. 4 is an explanatory diagram showing an arrangement relationship of a timing belt meshing with a driven pulley and a regulation roller that regulates the lifting of the timing belt, in the drive transmission device according to the embodiment of the invention described in claim 4;

FIG. 5 is an explanatory diagram showing a positional relationship between a timing belt that meshes with a driven pulley and a toothed regulation roller that regulates lifting of the timing belt, in the drive transmission device according to the fifth aspect of the present invention.

FIG. 6 is a schematic configuration diagram of a conventional drive transmission device.

FIG. 7 is a state explanatory view showing a normal meshing state of a timing belt and a pulley in the drive transmission device.

FIG. 8 is a state explanatory view showing a lifted state of the timing belt.

[Explanation of symbols]

 23.24.25 Pulley 30 Timing Belt 35 Pressing Roller (Rotating Body) 40 Fixing Member 44.51 Fixed Shaft 45 Control Roller (Rotating Body) 50 Toothed Control Roller (Regulating Member) G Engagement Start Position

Claims (5)

[Claims] 1. A drive transmission device that transmits a driving force with a timing belt that is stretched between pulleys, at a position where the pulley and the timing belt start meshing with each other.
A drive transmission device in which a regulating member for suppressing the lifting of the timing belt is arranged outside the timing belt. 2. The drive transmission device according to claim 1, wherein a rotating body is used as the regulating member, and the rotating body is biased and pressed against the timing belt. 3. The drive transmission according to claim 1, wherein a fixing member is used as the restricting member, and the fixing member restricts the lifting of the timing belt beyond the meshing amount of the pulley and the timing belt. apparatus. 4. A rotating body is used as the regulating member, the rotating body is rotatably provided on a fixed shaft, and the floating of the timing belt is greater than the meshing amount of the pulley and the timing belt by the rotating body. Claim 1 which is regulated
The drive transmission device according to. 5. The drive transmission according to claim 4, wherein the timing belt is also provided with teeth on its outer periphery, a toothed rotary body is used as the rotary body, and the toothed rotary body is meshed with the timing belt. apparatus.