JPH08121559A - Drive transmitter - Google Patents

Abstract

PURPOSE: To provide a drive transmitter that hardly jumps tooth even if the belt tension is loosen in order to prevent noise caused by a timing belt engaging with a pulley. CONSTITUTION: A drive side pulley 1 and a driven side pulley 2 have a endless timing belt 3 laid across them. To prevent tooth jumping which is easily caused when a tension belt is loosened in order to prevent engaging noise of the timing belt 3 and the pulleys 1, 2, belt pressure contact rollers 4, 14 for preventing such noise are pressure contacted on the back side of the belt belt 3.

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 using a timing belt which is wound around a driving pulley and a driven pulley.

[0002]

2. Description of the Related Art In recent years, timing belts, which are also called toothed belts, have been widely used in drive transmission devices because of their excellent strength and precision. In the drive transmission device using such a timing belt, noise is likely to be generated from the timing belt, and it is required to reduce this noise as much as possible.

The following noises are considered as noises when driving the timing belt (references Austen, AEW, and T.Priedc, Automotive Die).
selEngines, SAE Paper 650165, (1965)). (1) A meshing impact sound generated when a belt tooth and a pulley tooth or a belt tooth groove portion and a pulley tooth top portion collide with each other at the beginning of meshing between the timing belt and the pulley. (2) Vibration at the time of meshing between the timing belt and the pulley (hereinafter referred to as "belt meshing vibration") propagates to the belt portion not meshing with the pulley, and the noise when the belt portion vibrates, so-called, String vibration sound. (3) Sound of vibration of air near the pulley due to vibration of the pulley. (4) Exhaust sound and suction sound of air in the incompletely meshed portion. (5) Friction noise generated between the flange portion of the pulley and the belt.

Of these, the two main are the meshing impact sound (1) and the string vibration sound (2). Most of the meshing impact sound (1) out of these is generated from the portion where the timing belt meshes with the pulley.

Regarding the noise during the operation of the timing belt, it is possible to lower the noise by loosening the belt tension. However, in this case, as a side effect, the belt teeth run over the pulley teeth, A so-called "tooth skipping" phenomenon easily occurs. When such tooth skipping occurs, the tooth portion of the belt is worn or the drive transmission is hindered.
Further, when tooth jumping occurs, the timing belt may stop. In the conventional drive transmission device, no measure has been taken to prevent such tooth jump.

On the other hand, it has already been described that the belt meshing vibration propagates to the belt portion which is not meshed with the pulley, and this belt portion causes vibration. Vibration sound, that is, string vibration is generated. Conventional drive transmission devices have not taken any measures to prevent or reduce such string vibration.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a drive transmission device capable of preventing tooth jumping even if the belt tension is loosened in order to prevent or reduce meshing noise between a timing belt and a pulley. To do.

Another object of the present invention is to prevent the vibration generated at the meshing portion of the timing belt and the pulley from propagating to the belt portion not meshing with the pulley,
It is an object of the present invention to provide a drive transmission device capable of suppressing generation of string vibration noise.

[0009]

In order to achieve the above object, the present invention provides a drive side pulley having teeth formed on the outer periphery thereof,
Similarly, an endless timing belt having teeth formed on the inner circumference is provided between the endless timing belt and at least one driven pulley having teeth formed on the outer circumference. In a drive transmission device in which the timing belt and the driven pulley are driven by the rotation driving force of the driving pulley so as to mesh with the drive pulley, the drive pulley and the driven pulley are included in the entire circumference of the timing belt. A drive transmission device is proposed which is located at at least one position of the belt portion wound around the belt and which is provided with a belt pressing means for pressing the belt portion against the pulley from the back portion of the belt portion.

Another object of the present invention is to achieve the above object by providing an inner circumference between a drive pulley having teeth formed on the outer circumference and at least one driven pulley having teeth formed on the outer circumference. An endless timing belt having teeth formed on the timing belt and the driven side by the rotational driving force of the driving side pulley so that the teeth of the inner circumference mesh with the teeth of the plurality of pulleys. In a drive transmission device for driving a pulley, a drive transmission device is proposed, in which, of the entire circumference of the timing belt, a belt portion immediately before meshing with at least one pulley is sandwiched by a roller pair.

It is effective that the belt pressure contact means has a roller that is biased in a direction of pressure contact with the timing belt and that rotates in accordance with the rotation of the timing belt.

Further, the belt pressing means is located at the beginning of meshing between the timing belt and the pulley or at a portion close thereto, and the beginning of meshing between the timing belt and the pulley is covered by a sound insulation member. It is effective that the belt pressure contact means is integrally assembled with the sound insulation member.

[0013]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is a diagram showing a main part of a drive transmission device according to an embodiment of the present invention. In the figure, reference numeral 1 denotes a drive side pulley having a tooth portion 1a formed over the entire length of the outer peripheral portion, and 2 is placed at a position separated from the drive side pulley 1 by a predetermined distance. The driven side pulley which formed is shown. In FIG. 1, one driven pulley 2
However, a plurality of driven pulleys 2 may be provided. An endless timing belt 3 having teeth 3a formed at a constant pitch over the entire length of the inner peripheral portion is stretched between at least one driven pulley 2 and the driving pulley 1 as described above. The tooth portion 3a of the belt 3 meshes with the tooth portions 1a and 2a of the plurality of pulleys 1 and 2 described above. The timing belt 3 is made of an elastic material such as rubber or a flexible material.

Both ends of the pulley shaft 1A of the driving pulley 1 and the pulley shaft 2A of the driven pulley 2 are rotatably supported by a device substrate (not shown). Drive side pulley 1
Is integrated with the pulley shaft 1A.
Is driven by a motor (not shown) in one direction, for example, in the A direction, directly or via an appropriate rotation transmission means.

The driving pulley 1 is rotated by driving the pulley shaft 1A, and the timing belt 3 and the driven pulley 2 are rotationally driven in the same direction as the driving pulley 1 accordingly. That is, the timing belt 3 and the driven pulley 2 are rotationally driven by the rotational driving force of the driving pulley 1. A pulley shaft 2A that is integrated with the driven pulley 2 is connected to a rotary load system (not shown), and this is driven to rotate by the rotation of the driven pulley 2. On the other hand, the driven body mounted on the timing belt 3 itself can be driven to reciprocate, and in such a case or in other cases, the driving pulley 1 may be driven to rotate normally and reversely. .

Here, the characteristic feature of this embodiment is that at least one portion of the belt portion wound around the driving side pulley 1 and the driven side pulley 2 in the entire circumference of the timing belt 3 is located. The belt pressing means for pressing the belt portion against the pulleys 1 and 2 is provided from the back of the belt portion.

The belt pressure contact means of the embodiment shown in FIG.
It has a roller that is urged in a direction in which it is pressed against the timing belt 3 and that rotates in accordance with the rotation of the timing belt.

Reference numeral 4 denotes the roller, and the roller 4 serves as a belt pressure contact roller and is in pressure contact with the back portion of the belt portion of the timing belt 3, which meshes with the drive pulley 1. The device board mentioned above,
A roller mounting lever 5 is pivotally supported by a shaft 6, and a belt pressing roller 4 is rotatably mounted on one lever end. A tension spring 8 is hung between the other lever end and the pin 7 provided on the device substrate.

By the force of the tension spring 8, the belt pressure contact roller 4 presses the above belt portion against the driving pulley 1. Similarly, the driven pulley 2 side is also provided with a belt pressure contact means including a belt pressure contact roller 14. The roller 14 is pressed against the back portion of the belt portion of the timing belt 3, which meshes with the driven pulley 2. are doing. The roller 14 is attached to the device substrate by the shaft 1.
A roller mounting lever 15 pivotally supported via 6 is rotatably mounted on one end of the roller mounting lever 15. A tension spring 18 is hung between the other lever end and a pin provided on the device substrate.

When the driving pulley 1 rotates in the direction of arrow A, tension is applied to the timing belt 3,
At the same time, the driven pulley 2 rotates. At this time, if the tension of the timing belt is strong, the timing belt 3
And a meshing noise is likely to be generated at the meshing portion between the pulleys 1 and 2. Therefore, in order to prevent or reduce such meshing noise, the belt tension is loosened as much as possible. With this configuration, the tooth portion of the belt rides on the tooth portion of the pulley, and the tooth jump easily occurs.

When the timing belt 3 is driven to rotate, the belt pressure contact rollers 4 and 14 rotate while being pressed against the back portion of the belt while being moved. For this reason,
Even if the belt tension is loosened in order to prevent or reduce the meshing noise between the timing belt and each pulley, the above-mentioned tooth jumping is less likely to occur due to the pressure contact between the belt pressure contact rollers 4 and 14.

As the belt pressing means, a pressing member which simply presses against the belt without rolling may be used. However, in this case, the driving load of the timing belt is increased and the belt is worn due to friction. Its life becomes short. Timing belt 3 is used as the belt pressure contact means.
By using the rollers 4 and 14 that follow the movement of, the driving load of the timing belt 3 can be reduced, and belt wear or the like is less likely to occur.

By the way, the timing belt is loosened in order to prevent the above-mentioned meshing sound, but the meshing sound at a somewhat low level may still be generated. This meshing sound is likely to be generated from the portion at the beginning of meshing.

FIG. 2 shows an embodiment in which such points are taken into consideration. The structure of the drive side pulley 1 and the driven side pulley 2 of the drive transmission device shown in the same figure, and the timing belt 3 wound around these pulleys 1 and 2, and the operation thereof are the same as those of the drive transmission device shown in FIG. There is no change. In addition, the drive transmission device shown in FIG.
A belt press-contact means for pressing the belt portion against the pulley is provided at at least one position of the belt portion wound around the driving pulley 1 and the driven pulley 2 from the back of the belt portion. It is similar to the drive transmission device shown in FIG. 1 in that the pressure contact means is composed of rotatable rollers 4 and 14 that pressure contact with the back portion of the timing belt 3.

In the embodiment shown in FIG. 2, the rollers 4, 14 are
The belt press-contacting means is located at the beginning of meshing between the timing belt 3 and the pulleys 1 and 2, or at a portion close thereto, and the timing belt 3 and the pulleys 1,
The beginning of meshing with 2 is covered with sound insulation members 9 and 19. The sound insulation member indicated by reference numeral 9 in FIG. 2 is
As shown in FIGS. 3 and 4, the side wall portions 9a, 9a on both sides are formed.
And a top wall portion 9b integrally provided at one end of both of them, and the side wall portions 9a, 9a on both sides and the top wall portion 9b mesh the timing belt 3 and the drive side pulley 1 with each other. The first part is covered.

A belt pressure contact roller 4 is rotatably mounted on the sound insulating member 9 with respect to the shaft 13 (FIG. 4) so as to be located between the side wall portions 9a, 9a. That is, the shaft 13 is fixed to both side wall portions 9a, 9a, and the roller 4 is rotatably supported by the shaft 13. In this way, the belt pressing roller 4 is integrally assembled with the sound insulation member 9.

The sound insulation member 9 is pivotally supported by the shaft 11 on the above-mentioned device substrate so as to be swingable, and the member 9 has a habit of turning clockwise in the drawing by the force of the tension spring 12. ing. The force of the tension spring 12 urges the belt pressure contact roller 4 in a direction of pressure contact with the timing belt 3, and when the drive side pulley 1 rotates in the direction of arrow A and the timing belt 3 rotates, the belt pressure contact roller 4 moves. The belt 3 rotates following the rotation of the belt 3.

The sound insulation member 19 provided on the driven pulley 2 side also has the same shape as the sound insulation member 9 provided on the drive pulley 1 side, and is integrally connected to the top wall portion 19b thereof. The both side wall portions 19a, 19a provided cover the beginning of meshing between the timing belt 3 and the driven pulley 2. The sound insulation member 19 has two side wall portions 19a,
The belt pressing roller 14 is attached via a shaft fixed to 19a.
Is rotatably mounted. Further, the sound insulation member 19 is the shaft 2
The roller 14 is pressed against the back of the belt by the force of the tension spring 22 which is pivotally supported by the device substrate 1 to be swingable and whose ends are locked by the substrate and the sound insulation member 19.

According to the above-mentioned structure, even if a low level meshing sound is emitted from the meshing portion of the timing belt 3 and the pulleys 1 and 2, by using the sound insulation members 9 and 19, such low noise is generated. It is possible to prevent the level meshing sound from radiating to the outside from the meshing portion. At the same time, due to the pressure contact of the belt pressure contact rollers 4 and 14, tooth skipping can be suppressed.

Further, the rollers 4 and 14 shown in FIGS.
Is a component of the belt pressure contact means,
As long as it can perform the equivalent pressure contact function, it can be replaced with another one. In addition, in order to enhance the sound insulation effect, a sound absorbing material such as foamed polyurethane may be attached to the inside of the sound insulation members 9 and 19. Further, it is most effective if the belt pressure contact means and the sound insulation member are provided for all the pulleys, but the intended object of the present invention can be achieved even if they are provided only for some pulleys. . Furthermore, the structure of the sound insulation member can be adopted in the drive transmission device which does not have the belt pressure contact means. For example, FIG.
Even if the drive transmission device is configured by omitting the rollers 4 and 14 in the configuration shown in FIG. 5, it is possible to suppress the problem that the meshing sound is emitted to the outside.

In this embodiment, the belt pressure contact means and the sound insulation member are integrated with each other. However, with this structure, the structure of the drive transmission device can be simplified and the cost can be reduced. Be advantageous It is also possible to configure the drive transmission device by separating the belt pressure contact means and the sound insulation member.

Next, another embodiment of the invention will be described.

FIG. 5 shows a drive transmission device of this embodiment. As in the case of FIG. 1, this drive transmission device includes a drive-side pulley 1 having teeth 1a formed on the outer periphery and at least one driven pulley 2 having teeth 2a formed on the outer periphery. , A timing belt 3 having teeth 3a formed on the inner periphery thereof is passed around, and the teeth 3a of the inner periphery are meshed with the teeth 1a, 2a of the plurality of pulleys 1, 2 to rotate the driving pulley 1. Drive the timing belt 3 and the driven pulley 2, and at least one of the entire circumference of the timing belt 3, that is, the belt portion immediately before meshing with the pulleys 1 and 2 in the illustrated example,
The pair of rollers 24 and 25 are used to hold them.
When the drive belt 1 rotates in the direction of arrow A, for example, when the timing belt 3 rotates, each roller pair 24, 25 rotates in the direction of arrow following the movement of the belt.

By the way, as described above, in the conventional drive transmission device, meshing vibration is generated in the initial stage where the timing belt meshes with the pulley, and this vibration propagates to the belt portion not meshing with the pulleys 1 and 2. However, string vibration is generated in the propagated belt portion. This vibration becomes a sound and is radiated from the belt portion. That is, a string vibration sound is generated.

Roller pairs 24, 24 and roller pairs 25, 2
The numeral 5 serves to stop the meshing vibration generated at the meshing portion between the timing belt and each pulley from propagating to the belt portion not meshing with the pulleys 1 and 2. In any case, the action of the roller pair suppresses the occurrence of string vibration, and thus suppresses the occurrence of string vibration sound radiated from the belt. In order to maximize this effect, it is advisable to bring the roller pairs 24 and 25 as close as possible to the meshing portion. The object of the present invention can be achieved by providing only one of the roller pairs 24 and 25, and at least one roller pair may be provided.

If the drive transmission device is constructed by appropriately combining the above-mentioned respective constructions, it becomes possible to more reliably prevent the conventional defects. For example, the drive transmission device is configured by using both the belt pressure contact means described with reference to FIGS. 1 to 3 and the roller pair configuration described with reference to FIG.

[0038]

According to the drive transmission device of the first aspect, in order to prevent or reduce the meshing noise between the timing belt and the pulley, tooth skipping can be prevented even if the belt tension is loosened.

According to the drive transmission device of the second aspect,
It is possible to prevent the drive load of the timing belt from increasing, and it is possible to prevent belt wear and the like from occurring.

According to the drive transmission device of the third aspect,
It is possible to prevent or reduce emission of the meshing sound to the outside of the meshing portion. Further, the structure of the drive transmission device can be simplified.

According to the drive transmission device of the fourth aspect,
Since the string vibration of the belt portion that is not meshed with the pulley can be suppressed, it is possible to make it difficult to radiate the string vibration sound generated from this portion to the outside of the belt.

[Brief description of drawings]

FIG. 1 is a diagram showing a main part of a drive transmission device according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a drive transmission device provided with means for blocking a meshing sound between a timing belt and a pulley.

FIG. 3 is an external perspective view of a sound insulation member that is an example of the configuration of the above shielding means.

FIG. 4 is a front view of the above sound insulation member.

FIG. 5 is a diagram showing a main part of a drive transmission device according to another embodiment of the present invention.

[Explanation of symbols]

 1 Drive Side Pulley 1a Tooth Part 2 Driven Side Pulley 2a Tooth Part 3 Timing Belt 3a Tooth Part 4 Roller 14 Roller 9 Sound Insulation Member 19 Sound Insulation Member 24 Roller Pair 25 Roller Pair

Claims (4)

[Claims] 1. An endless timing in which a tooth portion is formed on an inner peripheral portion between a driving pulley having a tooth portion formed on an outer peripheral portion and at least one driven pulley having a tooth portion similarly formed on an outer peripheral portion. A drive transmission device that spans the belt so that the teeth of the inner periphery of the belt mesh with the teeth of the plurality of pulleys, and that drives the timing belt and the driven pulley by the rotational driving force of the driving pulley. In at least one of the belt portions wound around the driving side pulley and the driven side pulley in the entire circumference of the timing belt.
A drive transmission device, characterized in that a belt pressure contact means for pressing the belt portion against a pulley is provided from a back portion of the belt portion located at a position. 2. The drive transmission device according to claim 1, wherein the belt pressure contact means has a roller which is biased in a direction of pressure contact with the timing belt and which rotates following the rotation of the timing belt. 3. The belt pressing means is located at a portion where the timing belt and the pulley start to mesh with each other, or a portion close to the portion, and the portion where the timing belt and the pulley start to mesh is covered with a sound insulating member. 3. The drive transmission device according to claim 1, wherein the belt pressure contact means is integrally assembled with the sound insulation member. 4. An endless timing in which a tooth portion is formed on an inner peripheral portion between a driving pulley having a tooth portion formed on an outer peripheral portion and at least one driven pulley having a tooth portion similarly formed on an outer peripheral portion. A drive transmission device that spans the belt so that the teeth of the inner periphery of the belt mesh with the teeth of the plurality of pulleys, and that drives the timing belt and the driven pulley by the rotational driving force of the driving pulley. 2. The drive transmission device according to claim 1, wherein a belt portion of the entire circumference of the timing belt immediately before meshing with at least one pulley is sandwiched by a pair of rollers.