JP2002250415A - Belt transmission gear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress noise generating from a flange set in a toothed pulley, as much as possible, in a belt transmission gear consisting of a toothed belt and toothed pulley. SOLUTION: A flange is not installed on a pulley of the least outside diameter or a drive pulley 1 out of a plurality of pulleys 1, 2, and so on which form a belt layout, but flanges 6, 7 are installed exclusively on the other pulleys 2, 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a belt type transmission in which a toothed belt and a toothed pulley are combined, and more particularly, to a technical field related to countermeasures for noise generated during operation.

[0002]

2. Description of the Related Art Generally, in a friction transmission device such as a flat belt or a V-belt, noise is not so much a problem in a normal use condition, but a belt including a toothed pulley and a toothed belt is used. With respect to the type transmission, noise at the time of high-speed rotation or the like is an important problem.

[0003] The noise of this belt type transmission device is mainly generated from the belt, and it is considered that the main components of the noise are meshing impact noise and string vibration noise. The meshing impact sound is a sound generated when the belt collides with the pulley teeth due to the polygonal effect of the pulley teeth when the tension side of the belt meshes with the drive pulley. On the other hand, the string vibration sound is a sound generated by the lateral vibration of the belt. When the meshing frequency matches the natural frequency of the lateral vibration of the belt, resonance occurs, and the noise level rises sharply.

As a countermeasure to reduce such noises mainly caused by the meshing impact sound and the string vibration sound, conventionally, for example, an appropriate interference width is applied between the belt teeth and the pulley teeth to engage with each other. Or a single belt is divided in the belt width direction to be transmitted by a plurality of belts having a reduced belt width (for example, when the belt width is 4
The belt width is 20 mm instead of the 0 mm belt 2
Transmission by means of a book belt) is known.

[0005]

By the way, in the belt type transmission having the toothed belt and the toothed pulley as described above, the toothed belt moves on its shaft on the toothed pulley during the operation of the transmission. It is manufactured in consideration of the direction of the core wire and the weave of the tooth cloth so as not to be offset in the direction. However, it is inevitable that the belt is offset on the pulley in one of its axial directions due to the parallel accuracy of the pulley shaft, the effect of the helically wound core wire, and the like. Therefore, conventionally, in order to suppress the deviation of the toothed belt on the toothed pulley, and to prevent the toothed belt from coming off the toothed pulley,
It is well known to provide a flange extending outward in the pulley radial direction on the outer peripheral portion of the side surface of the toothed pulley.

Specifically, in a belt-type transmission having a plurality of pulleys, the mounting positions of the flanges are as follows. That is, a case where flanges are attached to both side surfaces of every other pulley in the arrangement of a plurality of pulleys, a case where flanges are provided on one side surface of all pulleys, and the surface on which the flanges are provided are arranged in the pulley arrangement direction May be attached alternately. Further, in these cases, when a flange cannot be mounted on many pulleys, the pulleys are provided on pulleys located apart from each other so as to share the biasing force of the belt as evenly as possible. Furthermore, mounting flanges on many pulleys is disadvantageous in terms of cost, so it is recommended that flanges be mounted only on both sides of the small pulley in the belt layout used.

However, when flanges are provided on both side surfaces of the toothed pulley as described above, a new problem that noise is generated from the flange in addition to the noise (meshing impact sound and string vibration sound) generated from the belt. At present, no sufficient countermeasures have been proposed for the noise from the flange.

The present invention has been made in view of the above points, and an object of the present invention is to improve a belt-type transmission device including a toothed belt and a toothed pulley by improving the device configuration. Another object of the present invention is to minimize the noise generated from a flange attached to a toothed pulley.

[0009]

Therefore, in order to achieve the above object, the present invention does not provide a flange on a small pulley or a driving pulley from the viewpoint of reducing noise from a flange provided on the pulley. The flange is provided only on the other pulleys.

More specifically, the invention of claim 1 is directed to a belt-type transmission device including a plurality of pulleys including a driving and driven pulley, and a toothed belt wound around the pulley. In addition, a flange extending outward in the pulley radial direction is provided on an outer peripheral portion of at least one side surface of at least one of the other pulleys except for the smallest diameter pulley among the plurality of pulleys.

That is, the cause of the noise generated from the flange attached to the toothed pulley is that when the pulley tooth groove between the adjacent pulley teeth and the belt tooth mesh with each other vigorously, the pulley tooth groove and the belt tooth are engaged. It is thought to be caused by resonance of air (air column) between the part. The resonance of the air column is a sound of a fixed frequency determined by the pulley width.

If the flanges are provided on both side surfaces of the toothed pulley, the air column resonance tends to resonate because the air escape between the tooth groove portion of the pulley and the belt tooth portion becomes small. If the flange is not provided, an escape path for air is secured, so that resonance is less likely to occur and the noise level is reduced as compared with the case where the flange is provided.

In a belt layout including a plurality of toothed pulleys, if all the pulleys have flanges attached thereto, it is considered that the air column resonance sound is the largest.
The entrance side of the belt into the small pulley having the smallest diameter among the plurality of pulleys, or the entrance side of the belt into the drive pulley. The reason is that with a small pulley or drive pulley,
This is because the load and speed at the time of the biting of the belt teeth become the largest. For example, for a 2-axis deceleration layout,
The location where noise is most likely to occur is the small pulley and the drive pulley.

Therefore, according to the configuration of the first aspect, when all of the plurality of pulleys are provided with the flanges, the resonance sound of the air (air column) between the pulley tooth groove portion and the belt tooth portion becomes maximum. Since the flange is not provided for the minimum diameter pulley, the noise at the location where the loudest noise is generated can be reduced, and the noise level of the entire apparatus can be reduced. Therefore, it is possible to effectively reduce the noise from the flange while preventing the belt from shifting on the pulley.

A second aspect of the present invention is directed to a belt-type transmission including a plurality of pulleys including a driving and driven pulley, and a toothed belt wound around the pulley. A plurality of pulleys other than the smallest diameter pulley having the smallest diameter among the plurality of pulleys include a first one-side flange pulley provided with a flange extending outward in the pulley radial direction on one side outer peripheral portion, and the other pulley. A second one-sided flange pulley provided with a flange extending outward in the pulley radial direction at an outer peripheral portion of the side surface, wherein the first and second one-sided flange pulleys are arranged in a belt length direction. .

According to the above configuration, the same effect as that of the first aspect can be obtained. In addition, the first and second pulleys other than the plurality of pulleys except the minimum diameter pulley.
A flange is provided on one side of the one-sided flange pulley, so that generation of air column resonance from the first and second one-sided flange pulleys is prevented to reduce noise generated from the belt-type transmission. Can be.

A third aspect of the present invention is directed to a belt-type transmission including a plurality of pulleys including a driving and driven pulley, and a toothed belt wound around the pulley. A flange extending outward in the pulley radial direction is provided on an outer peripheral portion of at least one of both side surfaces of the other pulleys other than the driving pulley. With this configuration, the same effect as that of the first aspect can be obtained.

A fourth aspect of the present invention is directed to a belt-type transmission including a plurality of pulleys including a driving and driven pulley, and a toothed belt wound around the pulley. The other pulleys except the drive pulley include a first one-side flange pulley provided with a flange extending outward in the pulley radial direction on one side outer peripheral portion, and a pulley radial outer side on the other side peripheral portion. A second flange pulley provided with a flange, wherein the first and second flange pulleys are disposed in a belt length direction.

According to the above configuration, the same effect as the third aspect of the invention can be obtained. In addition to the above, similarly to the invention of claim 2, the first and second one-sided flange pulleys are provided with flanges on one side thereof among the plurality of pulleys other than the drive pulley. The generation of air column resonance from the first and second one-sided flange pulleys can be prevented, and the noise generated from the belt-type transmission can be reduced.

A fifth aspect of the present invention is directed to a belt-type transmission including a plurality of pulleys including a driving and driven pulley, and a toothed belt wound around the pulley. A flange extending outward in the pulley radial direction is provided at an outer peripheral portion on both sides of at least the smallest diameter pulley among the plurality of pulleys.
When the teeth of the toothed belt bite into the teeth of the pulley, an air escape portion is formed to allow the air in the space surrounded by the flange, the teeth and the teeth to escape to the outside. .

With the above configuration, the air between the pulley tooth grooves and the belt teeth can escape to the air escape portion when the toothed belt meshes with the toothed pulley, so that the resonance noise of the air column is reduced. be able to. Therefore, it is possible to effectively suppress the noise from the flange while preventing the belt from shifting on the pulley.

A sixth aspect of the present invention is directed to a belt-type transmission including a plurality of pulleys including a driving and driven pulley, and a toothed belt wound around the pulley. A flange extending outward in the pulley radial direction is provided at least on the outer peripheral portions of both side surfaces of the driving pulley, and the flange and the teeth are provided on the driving pulley when the tooth portion of the toothed belt is engaged with the tooth groove portion of the pulley. An air escape portion is formed to allow air in a space surrounded by the groove portion and the tooth portion to escape to the outside. With this configuration, the above-mentioned claim 5
The same effect as described above can be obtained.

According to a seventh aspect of the present invention, in the belt type transmission of the fifth or sixth aspect, the air escape portion is a through hole formed in a flange corresponding to the tooth groove portion of the pulley so as to penetrate the flange. It is characterized by the following. In the invention according to claim 8, in the belt type transmission according to claim 5 or 6, the air escape portion is a groove formed on the bottom surface of the tooth groove of the pulley so as to extend in the length direction of the tooth groove. It is characterized by the following. According to these inventions, a preferable configuration of the air escape portion can be specifically obtained.

In the ninth aspect of the present invention, the third, fourth or eighth aspect
In any one of the belt type transmissions, the driving pulley is a smallest-diameter pulley having the smallest diameter among the plurality of pulleys.

[0025]

(Embodiment 1) FIGS. 1 (a) and 1 (b) show a belt type transmission A according to an embodiment of the present invention.
Are shown below. The belt-type transmission A according to the present embodiment includes a plurality of toothed pulleys 1 to 4 including a driving and driven pulley, and a toothed belt 5 wound around each of the pulleys. That is, in the figure, 1 is a driving pulley composed of a toothed pulley, 2 to 4 are similar driven pulleys, and a toothed belt 5 is wound around each of the pulleys 1, 2,. By rotating the driving pulley 1, transmission is performed from the driving pulley 1 to each of the driven pulleys 2 to 4.

As shown in FIGS. 2 and 3, the toothed belt 5 includes a belt body 9 made of an elastic material, and the belt body 9 is made of, for example, rubber or polyurethane. A core wire 10 as a tensile member is embedded on the pitch line of the belt body 9. This core wire may be made of rubber or polyurethane,
Glass fiber and aramid fiber are mainly used,
Other fibers such as carbon and PBO may be used. A plurality of belt teeth 11, 11,... Having a substantially trapezoidal tooth profile are formed on the land line of the belt body 9 at a constant tooth pitch in the belt length direction.

When the belt body 9 is made of rubber as described above, a woven fabric 12 made of synthetic fiber is attached to the surface of the belt teeth 11. The woven fabric is preferably a polyamide fiber, but may be a polyester fiber. On the other hand, when the belt body 9 is made of polyurethane, the belt teeth 11
No woven cloth 12 is provided on the surface of the belt body 9 and only the core wire is embedded in the belt body 9.

On the other hand, as shown in FIG. 3, the drive and driven pulleys 1, 2,... Formed of toothed pulleys are made of, for example, sintered metal, aluminum, synthetic resin, etc. .. (Only one is shown) provided at a plurality of pitches.
Each portion between the pulley tooth grooves 15, 15 becomes a pulley tooth 16, 16,....

The drive pulley 1 is fixed to a drive shaft 1a supported so as to be able to rotate around its axis.
It is configured smaller than the other driven pulleys 2-4. The driven pulleys 2 to 4 are rotatably supported by rotating shafts 2a, 3a, and 4a fixed in parallel with the drive shaft 1a.

As a feature of the present invention, at least one side surface of at least one of the pulleys 2 to 4 other than the smallest diameter pulley 1 having the smallest diameter among the toothed pulleys 1 to 4 constituting the belt type transmission A. The outer peripheral portion is provided with a flange extending outward in the pulley radial direction.

That is, in the present embodiment, as shown in FIGS. 1A and 1B, no flange is provided on the driving pulley 1 which is the pulley with the smallest diameter and the smallest diameter. Further, the driven pulley 2 has two side surfaces 2b,
A substantially disk-shaped flange 6, 6 having a diameter larger than the outer diameter of the driven pulley 2 is fixed to 2b so as to be concentric with the axis of the pulley 2. Similarly, substantially disc-shaped flanges 7, 7 are fixed to both side surfaces 4b, 4b of the driven pulley 4, respectively. In addition, the driven pulley 3
Is not provided with a flange.

Incidentally, flanges extending outward in the pulley radial direction may be formed integrally with the toothed pulleys at the outer peripheral portions of both side surfaces of the toothed pulley.

As described above, the toothed belt 5 rotates between the pulleys 1 to 4 with the rotation of the driving pulley 1 to transmit the driving force, and is provided on the driven pulleys 2 and 4. The offset of the toothed belt 5 on the pulley is regulated by the flanges 6 and 7.

At this time, as shown in FIG. 3, when the flanges 6, 7 are attached to the toothed pulleys 2, 4, noise is generated from the flanges 6, 7, but the noise is generated by the adjacent pulleys. When the pulley tooth groove portion 15 between the tooth portions 16 and 16 and the belt tooth portion 11 vigorously mesh with each other, the air (air column) between the pulley tooth groove portion 15 and the belt tooth portion 11 resonates.

That is, the air in the gap M between the pulley tooth groove portion 15 and the belt tooth portion 11 is generated when the gap M
As a result, the escape path is reduced, so that resonance is more likely to occur as compared with a toothed pulley provided with no flange, and noise is generated.

Further, when the flanges are attached to all of the plurality of pulleys 1 to 4, it is considered that the air column resonance sound is considered to be the largest among the pulleys 1 to 4 having the smallest diameter. (Or the drive pulley) is the entrance side of the belt into 1. The reason for this is that the load and speed at which the belt teeth 11, 11,... Bit into the pulley tooth grooves 15, 15,. Therefore, a plurality of pulleys 1
4, the smallest diameter pulley (or drive pulley) 1 is a main cause of noise from the flange.

However, conventionally, there has been no idea of specifying a toothed pulley to which a flange is attached from the viewpoint of reducing noise generated from such a flange. In this case, a larger noise is generated than when a flange is attached to another toothed pulley.

On the other hand, according to the configuration of the present invention, when the flanges are provided on all of the plurality of toothed pulleys 1 to 4, the pulley 1 has a smaller diameter than the minimum diameter pulley 1 in which the noise from the flanges becomes largest. Is not provided, the noise at the place where the loudest noise is generated can be reduced, and the noise level of the entire apparatus can be reduced. Therefore, the flanges 6 and 7 provided on the other driven pulleys 2 and 4 can prevent the toothed belt 5 from shifting on the pulleys, and can effectively reduce noise from the flanges.

In this embodiment, the driving pulley and the minimum diameter pulley having the smallest diameter among the plurality of pulleys coincide with each other. However, the present invention is not limited to this. That is, when the driving pulley and the minimum diameter pulley do not coincide with each other, a flange may be provided on at least one of the toothed pulleys other than the minimum diameter pulley. At least one of the pulleys may be provided with a flange.

In this embodiment, at least one of the toothed pulleys 2 to 4 except the minimum diameter pulley (drive pulley) 1 is provided with a flange. However, the present invention is not limited to this. A flange may be provided on all of the other pulleys except the small-diameter pulley or the driving pulley.

(Embodiment 2) FIGS. 4 and 5 show Embodiment 2 of the present invention (in the following embodiments, the same parts as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof will be omitted. In the first embodiment, the driven pulleys 2 and 4 are provided with flanges, whereas the driving pulley 1 is provided with flanges and an air escape portion described later is formed. .

That is, in this embodiment, at least the smallest diameter pulley 1 having the smallest diameter among the toothed pulleys 1-4.
A flange 8 extending outward in the pulley radial direction is provided on an outer peripheral portion of both side surfaces of the pulley. At least one of the minimum diameter pulley 1 or the flange 8 provided on the minimum diameter pulley 1 has a toothed belt 5 in a pulley tooth groove portion 15. An air escape portion is formed to allow air in a space surrounded by the flange 8, the pulley tooth groove portion 15 and the belt tooth portion 11 to escape to the outside when the belt tooth portion 11 is engaged.

More specifically, as shown in FIG. 5, the air escape portion is formed near the bottom of the pulley tooth groove 15 on the side of the flange 8 corresponding to the pulley tooth groove 15 of the minimum diameter pulley 1. Through hole 2 formed to penetrate through
It is one. The through hole 21 has a circular shape as shown in the figure, but may have another shape.

As described above, the toothed belt 5 rotates between the pulleys 1 to 4 with the rotation of the driving pulley 1 to transmit the driving force, and the flange 8 provided on the driving pulley 1 Thereby, the offset of the toothed belt 5 on the pulley is regulated.

At this time, the toothed belt 5 and the minimum diameter pulley 1
Even when the gap between the pulley tooth groove 15 and the belt tooth 11 is shielded by the flange when meshing with the air, the air in the gap can escape to the air escape portion, thus reducing the resonance noise of the air column. Can be done. Therefore, it is possible to effectively suppress the noise from the flange while preventing the belt from shifting on the pulley.

The present invention is not limited to this. For example, as shown in FIG. 6, the air escape portion is provided on the bottom surface of the pulley tooth groove 15 of the minimum diameter pulley 1. The groove 22 may be formed to extend in the vertical direction. In FIG. 6, the groove shape of the groove portion 22 is a semicircular shape, but is not limited thereto, and may be another shape such as a rectangular shape.

In the present embodiment, the driving pulley and the minimum diameter pulley having the smallest diameter among the plurality of pulleys coincide with each other. However, the present invention is not limited to this. That is, when the drive pulley does not match the minimum diameter pulley, an air escape portion may be formed on the minimum diameter pulley, or an air escape portion may be formed on the drive pulley.

(Embodiment 3) FIG. 7 shows Embodiment 3 of the present invention.
In the first embodiment, flanges 6, 6, 7, 7 are provided on both side surfaces 2b, 2b, 4b, 4b of driven pulleys 2, 4, respectively.
4 of the two side surfaces 2b, 2b, 4b, 4b,
4b are provided with flanges 26 and 27, respectively. Further, in the belt type transmission of the present embodiment, the driven pulley 3 is different from that of the belt layout including the toothed pulleys 1 to 4 and the belt 5 of the first embodiment.
Is not provided. That is, the toothed pulley 1 is a driving pulley and a minimum diameter pulley having the smallest diameter among the plurality of pulleys 1, 2, and 4.

As shown in FIG. 7, in the belt-type transmission according to the present embodiment, a plurality of pulleys 2 and 4 other than the minimum-diameter pulley 1 A first one-side flange pulley 2 provided with an outwardly extending flange 26 and a second one-sided flange pulley 4 provided with a flange 27 extending outward in the pulley radial direction on the outer peripheral portion of the other side surface 4b. The second one-side flange pulleys 2 and 4 are arranged in the length direction of the belt 5. That is, the manner in which the flanges are provided on one side surface of the pulley provided with the flanges is alternated in the belt length direction.

In this manner, the toothed belt 5 rotates between the pulleys 1, 2, and 4 with the rotation of the driving pulley 1, and the driving force is transmitted. , 27 alternately restrains the pulley from shifting in the axial direction on the pulley.

At this time, the same effect as in the first embodiment can be obtained. In addition, the minimum diameter pulley 1
The first and second one-sided flange pulleys 2 and 4 as a plurality of other pulleys 2 and 4 except for the side surfaces 2b and 4b
Since the flanges 26 and 27 are provided on the first and second flanges, generation of air column resonance from the first and second one-sided flange pulleys 2 and 4 can be prevented, and noise generated from the belt-type transmission can be reduced. .

In the present embodiment, the belt-type transmission is constituted by three pulleys. However, the present invention is not limited to this, and may be constituted by other plural pulleys. Further, in this case, at least one first and second one-sided flange pulleys may be provided, so that at least one of the minimum diameter pulley or the driving pulley and the other pulleys except the first and second one-sided flange pulleys are provided with flanges. May be provided.

In this embodiment, the driving pulley and the minimum diameter pulley having the smallest diameter among the plurality of pulleys coincide with each other. However, the present invention is not limited to this. That is, when the driving pulley and the minimum diameter pulley do not match, a flange may be provided on one side surface of a plurality of pulleys other than the minimum diameter pulley,
A flange may be provided on one side surface of a plurality of pulleys other than the drive pulley.

[0054]

Next, a specific embodiment will be described. In this embodiment, as shown in FIG. 8, a belt-type transmission having a two-axis layout including a driving pulley 31 and a driven pulley 32 formed of toothed pulleys, and a toothed belt 35 wound around the two pulleys. Was measured for noise.

The toothed belt 35 used in this embodiment has a tooth pitch of 14 mm, a nominal belt length (pitch circumferential length) of 1652 mm, and a nominal belt width of 40 mm. The drive pulley 31 has 26 pulley teeth, so that the drive rotation speed can be increased or decreased. The driven pulley 32 has 45 pulley teeth, and is configured to apply a static load P of 2452N in a direction away from the driving pulley 31.

Further, as shown in FIG.
Has a smaller outer diameter than the driven pulley 32. In other words, the drive pulley 31 is the smallest diameter pulley having the smallest diameter among the plurality of toothed pulleys 31 and 32 constituting the belt-type transmission.

Then, the driving pulley (minimum diameter pulley) 31
The transmission device was operated at room temperature and the noise generated was measured for each of the case where only the flange was provided and the case where the flange was provided only for the driven pulley 32 other than the minimum diameter pulley. . At this time, the noise at a position L = 1000 mm away from the center of the pulley to be measured was measured by a sound collector.

FIG. 9 is a graph showing the results of noise measurement in each case. In the figure, the horizontal axis represents the rotation speed of the drive pulley 32, and the vertical axis represents the noise level of the generated noise. The graph shown by the solid line in FIG. 4 shows the noise level when only the driven pulley 32 (large-diameter pulley) is provided with a flange, and the graph shown by the broken line shows that the flange is provided only on the driving pulley (minimum-diameter pulley) 31. Indicates the noise level when provided.

As shown in the figure, the driving pulley (minimum diameter pulley) 3
1 and the driven pulley 32
It can be seen that the noise level is lower when the flange is provided only on the (large diameter pulley).

[0060]

As described above, according to the first aspect of the present invention, there is provided a belt-type transmission including a plurality of pulleys including a driving and driven pulley and a toothed belt wound around the pulleys. Of the pulleys, a flange extending outward in the pulley radial direction is provided on the outer peripheral portion of at least one of both side surfaces of the other pulleys except the smallest diameter pulley. According to the third aspect of the present invention, there is provided a belt-type transmission including a plurality of pulleys including a driving and driven pulley, and a toothed belt wound around the pulleys,
By providing a flange extending radially outward on at least one of both side surfaces of the other pulleys other than the drive pulley, noise from the flange is effectively reduced while preventing the belt from shifting on the pulley. Thus, noise of the entire apparatus can be suppressed.

According to the second aspect of the present invention, a belt-type transmission including a plurality of pulleys including a driving and driven pulley and a toothed belt wound around the pulleys has the smallest diameter among the plurality of pulleys. A plurality of pulleys other than the minimum diameter pulley include a first one-side flange pulley provided with a flange extending outward in the pulley radial direction on one side outer peripheral portion, and a flange extending outward in the pulley radial direction on the other side outer peripheral portion. And a second one-sided flange pulley provided.
The first and second one-sided flange pulleys are arranged in the belt length direction. According to a fourth aspect of the present invention, there is provided a belt-type transmission including a plurality of pulleys including a driving and driven pulley, and a toothed belt wound around the pulleys.
A plurality of pulleys other than the drive pulley are provided with a first one-side flange pulley provided with a flange extending outward in the pulley radial direction on one side outer peripheral portion and a flange extending outward in the pulley radial direction on the other side peripheral portion. And a second one-side flange pulley provided, and by arranging the first and second one-side flange pulleys in the belt length direction, it is possible to obtain the same effects as those of the first and third aspects of the invention. .
In addition, among the plurality of pulleys other than the minimum diameter pulley or the driving pulley, the generation of air column resonance from the first and second one-sided flange pulleys is prevented, and the noise generated from the belt type transmission is reduced. Can be reduced.

According to the fifth aspect of the present invention, there is provided a belt type transmission device including a plurality of pulleys including a driving and driven pulley and a toothed belt wound around the pulleys, wherein at least the largest diameter of the plurality of pulleys is provided. Flanges extending radially outward of the pulley are provided on the outer peripheral portions on both sides of the small minimum diameter pulley, and when the teeth of the toothed belt bite into the tooth grooves of the pulley, the flange, the tooth grooves and the teeth are provided. By forming an air escape part to allow the air in the space surrounded by the part to escape to the outside, the resonance noise of the air column is reduced, preventing the belt from shifting on the pulley and effectively from the flange. Noise can be suppressed.

According to a sixth aspect of the present invention, there is provided a belt-type transmission including a plurality of pulleys including a driving and driven pulley, and a toothed belt wound around the pulleys.
A flange extending outward in the pulley radial direction is provided at least on the outer peripheral portions of both side surfaces of the drive pulley, and the drive pulley includes a flange, a tooth groove portion, and a tooth portion when the tooth portion of the toothed belt bites into the tooth groove portion of the pulley. By forming an air escape portion for allowing the air in the enclosed space to escape to the outside, the same effect as in the fifth aspect can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating an outline of a belt-type transmission according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing a toothed belt.

FIG. 3 is an explanatory diagram showing a meshing state between a toothed belt and a toothed pulley.

FIG. 4 is a schematic view of a belt type transmission according to a second embodiment of the present invention, corresponding to FIG.

FIG. 5 is an explanatory diagram showing an enlarged view of a toothed belt and a toothed pulley according to a second embodiment.

FIG. 6 is an enlarged view of the toothed belt and the toothed pulley according to the second embodiment, corresponding to FIG. 5;

FIG. 7 is a plan view schematically showing a belt-type transmission according to a third embodiment.

FIG. 8 is an explanatory diagram illustrating a noise measurement system of the belt-type transmission according to the embodiment of the present invention.

FIG. 9 is a graph showing noise measurement results according to the present embodiment.

[Description of Signs] A Belt type transmission 1 Drive pulley (minimum diameter pulley) 2, 3, 4 Follower pulley 5 Toothed belt 6, 7, 26, 27 Flange 2b, 4b Pulley side 21 Through hole (air escape portion) 22 groove (air escape part)

Claims (9)

[Claims] 1. A belt-type transmission comprising: a plurality of pulleys including a driving and driven pulley; and a toothed belt wound around the pulleys, wherein the smallest diameter of the plurality of pulleys has the smallest diameter. A belt-type transmission, wherein a flange extending outward in the pulley radial direction is provided on an outer peripheral portion of at least one of both side surfaces of the other pulley except for the pulley. 2. A belt-type transmission comprising a plurality of pulleys including a driving and driven pulley, and a toothed belt wound around the pulleys, wherein the minimum diameter of the plurality of pulleys is the smallest. A plurality of pulleys other than the pulley are provided with a first one-side flange pulley provided with a flange extending outward in the pulley radial direction on one side outer peripheral portion, and a flange extending outward in the pulley radial direction on the other side peripheral portion. And a second one-sided flange pulley, wherein the first and second one-sided flange pulleys are arranged in a belt length direction. 3. A belt-type transmission comprising a plurality of pulleys including a driving and driven pulley and a toothed belt wound around the pulley, wherein at least one of the other pulleys except the driving pulley is provided. A belt-type power transmission, wherein flanges extending outward in the radial direction of the pulley are provided on outer peripheral portions of both side surfaces. 4. A belt-type transmission including a plurality of pulleys including a driving and driven pulley, and a toothed belt wound around the pulley, wherein the plurality of pulleys other than the driving pulley are: A first one-sided flange pulley provided with a flange extending radially outward on one side outer peripheral portion, and a second one-sided flange pulley provided with a flange extending radially outward on the other side outer peripheral portion. A belt-type transmission, wherein the first and second one-sided flange pulleys are arranged in a belt length direction. 5. A belt-type transmission comprising: a plurality of pulleys including a driving and driven pulley; and a toothed belt wound around the pulley, wherein at least the smallest diameter of the plurality of pulleys is the smallest. A flange extending radially outward from both sides of the small-diameter pulley is provided on the outer peripheral portion. When the tooth portion of the toothed belt meshes with the tooth groove portion of the pulley, the flange, tooth groove portion, and A belt type transmission device, wherein an air escape portion is formed to allow air in a space surrounded by the teeth to escape to the outside. 6. A belt-type transmission including a plurality of pulleys including a driving and driven pulley, and a toothed belt wound around the pulley, wherein at least outer peripheral portions of both side surfaces of the driving pulley have a pulley radial direction. An outwardly extending flange is provided, and the air in the space surrounded by the flange, the tooth groove and the tooth portion is released to the outside when the tooth portion of the toothed belt bites into the tooth groove portion of the drive pulley. A belt transmission having an air escape portion formed therein. 7. The belt type transmission according to claim 5, wherein the air escape portion is a through hole formed in a flange corresponding to a tooth groove portion of the pulley so as to penetrate the flange. Belt type transmission. 8. The belt-type transmission according to claim 5, wherein the air escape portion is a groove formed on a bottom surface of the tooth groove of the pulley so as to extend in a longitudinal direction of the tooth groove. Belt-type transmission. 9. The belt-type transmission according to claim 3, wherein the drive pulley is a smallest-diameter pulley having the smallest diameter among the plurality of pulleys.