JP2001336615A - Toothed pulley and toothed belt - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a toothed pulley and a toothed belt for not reducing the magnitude of transmittable motive power and not reducing durability even when a phase shift is caused. SOLUTION: Since this toothed pulley 10 is arranged so that a pair of left and right helical tooth sets 12 and 13 bilaterally symmetrical in the width direction are mutually opposed by leaving clearance 14 having a prescribed dimension in the width direction, even if the phase shift is caused between the pair of left and right helical tooth sets 12, and 13, partial loading is not caused between teeth of the toothed belt combined with a tooth of the toothed pulley 10. Thus, the transmittable motive power is not reduced and the durability of the toothed belt is not reduced when the partial loading is caused between both teeth. Since the occurrence of the phase shift between the pair of left and right helical tooth sets 12 and 13 can be allowed, the toothed pulley 10 can be inexpensively manufactured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toothed pulley and a toothed belt used for power transmission, and more particularly, to a circle between a pair of right and left helical teeth which cross each other to form a toothed tooth. The present invention relates to a technology for improving power transmission so as not to decrease or endurance to decrease even when circumferential phase deviation occurs.

[0002]

2. Description of the Related Art Conventionally, a toothed pulley 1 and a toothed belt 2 as shown in FIG. 8 have been used for transmitting power.

In this pulley 1 with toothed teeth, a large number of toothed teeth 4 are protruded at equal intervals in the circumferential direction on an outer peripheral surface 3 of a cylindrical column. The helical teeth 4a and 4b are combined with each other. Therefore,
When manufacturing this pulley 1 with toothed teeth, a pair of left and right helical pulleys having helical teeth 4a and 4b are individually formed by cutting a cylindrical metal material with a hobbing machine. I do. Then, the pair of left and right helical pulleys is coaxially combined and fixed, whereby the toothed pulley 1 can be manufactured.

The mountain-toothed belt 2 is formed by projecting a large number of mountain teeth 6 at equal intervals in the longitudinal direction of the belt on the surface of an endless belt-shaped base 5. Numeral 6 is formed by combining symmetrical helical teeth 6a and 6b with each other. Therefore, the mold used for manufacturing the belt 2 with the toothed teeth has a structure in which the mold divided into two symmetrically in the left-right direction is combined coaxially and in phase in the longitudinal direction of the belt.

[0005]

When a pair of left and right helical pulleys is combined to manufacture the toothed pulley 1 as described above, a circumferential direction is formed between the pair of left and right helical pulleys. May cause slight phase deviation. When the pair of left and right helical pulleys is fixed to each other in a state where such phase deviation occurs, the toothed pulley 1 is completed.
As shown enlarged in FIG. 9, a pair of left and right helical teeth 4a, 4
A phase deviation δ in the circumferential direction occurs between b.

When the belt 2 is wound around the pulley 1 in which the phase deviation δ occurs, as shown in an enlarged view of FIG. 10, the helical teeth 4b on the right side of the pulley 1 and the right side of the belt 2 on the right side of the belt 2 are shown. The helical teeth 6b are in close contact with each other, but the helical teeth 4a on the left side of the pulley 1 and the helical teeth 6a on the left side of the belt 2 are illustrated.
A gap S is generated between them, so that the mountain teeth 4 and 6 hit each other.

When power is applied to the pulley 1 in a state where the mountain teeth 4 and 6 are in one contact with each other, the belt 2 tends to be displaced rightward in FIG. The peaks 4c of the mountain teeth 4 and the valleys 6c of the mountain teeth 6 on the side of the belt 2 engage in the width direction of the pulley 1, so that the belt 2 can be displaced to the right in the drawing from the state shown in FIG. It is not possible to prevent the one-sided contact between the mountain teeth 4 and 6 from being eliminated.

[0008] Similarly, when the molds divided into two symmetrically in order to manufacture the belt 2 with the toothed teeth are combined as described above, a slight phase deviation in the circumferential direction occurs between the pair of left and right molds. Sometimes. When the belt 2 with mountain teeth is completed by using a mold having such a phase deviation, the mountain teeth 6 of the belt 2 with mountain teeth are formed as shown in FIG. A phase deviation δ occurs in the belt longitudinal direction between the pair of left and right helical teeth 6a and 6b. Then, as shown in FIG. 12, the helical teeth 6 b on the right side of the belt 2 and the pulley 1
Is in close contact with the right helical teeth 4b of the belt 2, but a gap S is formed between the left helical teeth 6a of the belt 2 and the left helical teeth 4a of the pulley 1 in the drawing. 6 hit each other.

If power is applied to the belt 2 in a state where the mountain teeth 4 and 6 are in one-side contact with each other, the belt 2 tends to be displaced to the left in FIG. 6 and the valleys 4d of the teeth 4 on the pulley 1 side engage with the pulley 1 in the axial direction. As a result, the belt 2 cannot be displaced to the left from the state shown in FIG. 12, and the one-sided contact between the mountain teeth is not eliminated.

When the mountain teeth 4 and 6 hit each other, not only the power that can be transmitted is reduced, but also
The durability of the belt 2 is reduced, and in the worst case, the belt 2 is broken and power transmission becomes impossible.

However, the toothed teeth 4 of the toothed pulley 1
In order to prevent the phase deviation δ from occurring, it is necessary to fix the pair of left and right helical pulleys separately manufactured in a state where the phases are completely matched, but it takes time and effort to produce Production costs will increase significantly. Similarly, in order to prevent the phase deviation δ from occurring in the tooth teeth 6 of the toothed belt 2, it is necessary to fix the pair of left and right molds in a state where the phases are completely matched, Production takes a lot of time and production costs increase significantly.

Accordingly, an object of the present invention is to solve the above-mentioned problems of the prior art, and to reduce the power that can be transmitted even if the toothed pulley or the toothed belt has an out-of-phase tooth. It is an object of the present invention to provide a toothed pulley and a toothed belt which can be prevented from being worn or having reduced durability and capable of preventing an increase in production cost.

[0013]

According to a first aspect of the present invention, there is provided a toothed pulley used for power transmission in combination with a toothed belt, wherein a pair of left and right wheels is symmetrical in the pulley width direction. The helical tooth sets are arranged so as to face each other with a predetermined gap in the width direction. The width W of the gap in the width direction
Is the inclination angle of the tooth traces of the pair of left and right helical teeth, respectively, and the amount of phase deviation in the circumferential direction between the pair of left and right helical teeth is δ.
Is set so as to satisfy the relationship of W ≧ δ / tan θ. In addition, the gap provided between the pair of left and right helical teeth is formed by crossing the pair of left and right helical teeth with each other and forming a mountain tooth, and then a portion where the pair of left and right helical teeth intersect, in other words, the mountain tooth Can be formed by machining a concave groove extending in the pulley radial direction inward from the upper surface of the toothed teeth in the circumferential direction passing through the top of the tooth. At this time, the depth of the groove formed by machining is such that when the belt with a toothed tooth is wound around the toothed pulley, the bottom surface of the groove is located radially inward of the top of the toothed tooth in the pulley radial direction. What is necessary is just the depth which is located.

That is, the toothed pulley of the present invention is a conventional pulley with mountain teeth, in which the tops of the mountain teeth are cut out over a predetermined dimension in the pulley width direction. Accordingly, in the toothed belt combined with the toothed pulley of the present invention, the crests or valleys of the mountain teeth are formed at the respective inner ends of the pair of left and right helical teeth in the pulley width direction in the toothed pulley of the present invention. Can be displaced in the width direction of the pulley until it is engaged. At this time, the displacement of the toothed belt in the pulley width direction is
When the teeth on the pulley side and the mountain teeth on the belt side collide with each other, the partial force of the tension acting on the belt is generated in a direction in which the collapsing is eliminated. Further, the gap dimension W between the pair of left and right helical teeth of the pulley in the width direction of the pulley is such that the top or the valley of the tooth on the belt side is the pulley of each helical tooth of the pair of right and left helical teeth on the pulley side. Before engaging the inner corner in the width direction with the pulley width direction, the belt-side mountain teeth and the pulley-side teeth are set so as to be in close contact with each other to eliminate the one-side contact. Therefore, according to the present invention, even if there is a phase deviation in the circumferential direction of the pulley between the pair of left and right helical teeth forming the teeth of the toothed pulley, the tooth of the toothed pulley and the mountain tooth of the toothed belt are not affected. Will be automatically eliminated. As a result, the power that can be transmitted is not reduced, and the durability of the toothed belt combined with the toothed pulley is not reduced. Furthermore, according to the present invention, since it is permissible to cause a phase deviation in the circumferential direction between the pair of left and right helical teeth forming the teeth of the toothed pulley, the pair of left and right helical teeth can be circumferentially moved. Accuracy required for phase matching is no longer strict, and an increase in the production cost of the toothed pulley can be prevented.

A third aspect of the present invention is a toothed belt used for power transmission in combination with a toothed pulley, wherein a pair of left and right helical teeth symmetrical in the belt width direction is provided. A gap of a predetermined dimension is provided in the direction to dispose them so as to face each other.
In addition, the width direction dimension W of the gap is defined as θ, the inclination angle of each tooth trace of the pair of left and right helical teeth, and δ as the phase deviation amount in the belt longitudinal direction between the pair of left and right helical teeth. And W
It is set so as to satisfy the relationship of ≧ δ / tan θ. Further, the gap provided between the pair of left and right helical teeth can be formed simultaneously and integrally with the pair of left and right helical teeth by folding the shape in advance into a mold for producing the toothed belt. Can be. Further, a gap provided between the pair of left and right helical teeth is formed as a pair of left and right helical teeth which are crossed with each other to form a mountain tooth. It can be formed by forming a concave groove extending through the top portion in the longitudinal direction of the belt and extending from the upper surface of the mountain tooth to the belt base side by machining. At this time, when the toothed belt is wound around the toothed pulley, the depth of the concave groove formed by machining is such that the bottom of the groove is located radially outward of the top surface of the tooth on the pulley side in the pulley radial direction. It is sufficient if the depth is such that is located.

That is, the toothed belt according to the present invention is obtained by cutting off the peaks or valleys of the mountain teeth of a conventional mountain toothed belt over a predetermined dimension in the belt width direction. Accordingly, in the toothed pulley combined with the toothed belt of the present invention, the crests or valleys of the mountain teeth are formed at the respective inner ends of the pair of left and right helical teeth in the belt width direction in the toothed belt of the present invention. Until it engages with the belt. At this time, the displacement of the toothed belt in the belt width direction occurs in a direction in which the one-sided contact is eliminated due to the component force of the tension acting on the belt when the mountain teeth on the pulley side and the teeth on the belt-side one side contact. The gap between the pair of left and right helical teeth of the belt in the belt width direction is the belt width of each helical tooth of the pair of left and right helical teeth on the belt side where the top or valley of the tooth on the pulley side is the belt. Before engaging the inner corner in the width direction with the belt width direction, the mountain teeth on the pulley side and the teeth on the belt side are set to be in close contact with each other to eliminate the one-side contact. Therefore, according to the present invention, even if a phase deviation in the belt longitudinal direction occurs between the pair of left and right helical teeth forming the teeth of the toothed belt, the teeth of the toothed belt and the toothed teeth of the toothed pulley are displaced. The one-way hit that occurs in between will be automatically eliminated. As a result, the power that can be transmitted is not reduced, and the durability of the toothed belt is not reduced. Furthermore, according to the present invention, it is possible to allow a phase deviation in the belt longitudinal direction between the pair of left and right helical teeth forming the teeth of the toothed belt. Manufacture and increase in production cost of the toothed belt can be prevented.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a toothed pulley and a toothed belt according to the present invention will be described below in detail with reference to FIGS. Here, FIG. 1 is a perspective view showing a part of the toothed pulley and the toothed belt of the first embodiment according to the present invention, FIG. 2 is an enlarged front view of a main part of the toothed pulley shown in FIG. 1, and FIG. FIG. 4 is an enlarged front view of an essential part schematically showing the operation of the toothed pulley shown in FIG. 1, and FIG.
FIG. 5 is a perspective view showing a part of the toothed pulley and the toothed belt of the embodiment, FIG. 5 is an enlarged front view of a main part of the toothed pulley shown in FIG. 4, and FIG. 6 schematically shows the operation of the toothed pulley shown in FIG. FIG. 7 is a table showing the experimental results of the toothed pulley and the toothed belt according to the present invention.

First Embodiment First, an embodiment of a toothed pulley according to the present invention will be described in detail with reference to FIGS.

The toothed pulley 10 shown in FIG. 1 is used for power transmission in combination with a toothed belt 20, and a pair of left and right helical teeth symmetrical in the width direction of the pulley are provided on an outer peripheral surface 11 of the pulley. The sets 12 and 13 are disposed so as to face each other with a gap 14 having a predetermined dimension in the width direction of the pulley. Further, flanges 15 and 16 are provided upright at both ends of the pulley outer peripheral surface 11 in the pulley width direction so that the toothed belt 20 wound around the toothed pulley 10 does not fall off.

The pair of left and right helical teeth 12, 13
Dimension W in the pulley width direction of the gap 14 provided between
Is a pair of left and right helical tooth sets 12, 1 as shown in FIG.
Assuming that the inclination angle of the tooth trace of No. 3 is θ and the amount of phase deviation in the circumferential direction is δ, the relationship is set so as to satisfy the relationship of W ≧ δ / tan θ.

The belt 20 with the toothed teeth shown in FIG.
Is the same as the conventional mountain toothed belt 2 shown in FIG. 8 except that the belt width is set in accordance with the toothed pulley 10, and a plurality of mountain teeth 2 are formed on the surface of the belt base 21.
2 are arranged at equal intervals in the longitudinal direction of the belt.

Next, the operation and effect of the toothed pulley 10 of the first embodiment having the above-described configuration will be described with reference to FIGS.

FIG. 2 shows the toothed pulley 10 of this embodiment.
As shown in FIG. 7, a phase deviation δ in the circumferential direction is generated between the pair of left and right helical teeth 12 and 13. As a result, when the toothed belt 20 is wound around the toothed pulley 10 of the present embodiment, a one-sided contact occurs between the toothed pulley 10 and the toothed belt 20 as shown in FIG.

However, the toothed pulley 1 of the present embodiment
Numeral 0 denotes a portion in which a peak 4c or a valley 4d of the mountain tooth 4 of the conventional toothed pulley 1 is cut out over a predetermined dimension W in the pulley width direction. Thereby, the toothed belt 20 wound around the toothed pulley 10 of the present embodiment is
As shown in FIG. 3, the tension acting on the valley 22 c of the tooth 22 is adjusted until the valley 22 c of the tooth 22 engages with the inner end 13 a of the helical set 13 on the right side in the pulley width direction. It can be displaced to the right in the figure by the component force.

At this time, a pair of left and right helical teeth sets 12 and 13 are provided.
The dimension W of the gap 14 between the pulleys in the pulley width direction is W ≧ δ / tan
θ is set to satisfy the relationship. As a result, the valleys 22c of the mountain teeth 22 of the mountain-toothed belt 20 are changed to the inner end 13a of the right side helical set 13 in the pulley width direction.
The toothed pulley 10
The pair of left and right helical teeth 12 and 13 and the mountain teeth 22 of the toothed belt 20 are in close contact with each other, and the one-side contact is eliminated.

Therefore, the toothed pulley 10 of the present embodiment
In this case, even if there is a phase deviation δ in the circumferential direction between the pair of left and right helical teeth 12 and 13, the toothed pulley 10
One-sided contact between the teeth of the toothed belt 20 and the mountain teeth of the toothed belt 20 is automatically eliminated. As a result, there is no possibility that the power that can be transmitted due to the one-sided contact is reduced or the durability of the toothed belt 20 is reduced. Further, in the toothed pulley 10 of the present embodiment, a pair of left and right helical teeth sets 12 and 13 are provided.
Since it is permissible that a phase deviation δ in the circumferential direction occurs between the pair, the precision required for circumferentially adjusting the phase of the pair of left and right helical teeth 12 and 13 is not severe, and the production of the toothed pulley 10 is reduced. It is possible to prevent an increase in cost.

Second Embodiment Next, an embodiment of a toothed belt according to the present invention will be described in detail with reference to FIGS.

The toothed belt 30 shown in FIG. 4 is used for power transmission in combination with a toothed pulley 40, and a pair of left and right lotus symmetrical in the belt width direction is provided on the surface of a belt base 31 thereof. The tooth sets 32 and 33 are disposed so as to face each other with a gap 34 having a predetermined dimension in the belt width direction.

The pair of left and right helical teeth 32, 33
Dimension W of the gap 34 provided therebetween in the pulley width direction
Is a pair of left and right helical teeth 32, 3 as shown in FIG.
Assuming that the inclination angle of the tooth trace of No. 3 is θ and the amount of phase deviation in the circumferential direction is δ, the relationship is set so as to satisfy the relationship of W ≧ δ / tan θ.

The toothed pulley 40 shown in FIG.
Except that the width of the pulley is set in accordance with the toothed belt 30, the pulley width is the same as the conventional pulley 1 with the toothed teeth shown in FIG. In addition, flanges 43 and 44 are provided upright at both ends in the width direction to prevent the toothed belt 30 from falling off.

Next, the operation and effect of the toothed belt 30 of the present embodiment having the above-described configuration will be described with reference to FIGS.
This will be described with reference to FIG.

The toothed belt 30 of the present embodiment has a structure shown in FIG.
As shown in (1), a phase deviation δ in the belt longitudinal direction occurs between the pair of left and right helical teeth 32, 33. This allows
When the toothed belt 30 according to the present embodiment is wound around the toothed pulley 40, a one-sided contact occurs between the toothed belt 30 and the toothed pulley 40 as shown in FIG.

However, the toothed belt 3 of the present embodiment
Numeral 0 denotes a portion in which the valley portion 6c or the top portion 6d of the mountain tooth 6 of the conventional toothed belt 2 is cut out over a predetermined dimension W in the belt width direction. As a result, when the toothed belt 30 of the present embodiment is wound around the toothed pulley 40, as shown in FIG. Until it engages in the belt width direction with the valley portion 42c of the tooth 42 of the attached pulley 40.
It can be displaced to the left in the figure by the component force of the tension acting on itself.

At this time, a pair of left and right helical teeth 32, 33
The dimension W of the gap 34 between the belts in the belt width direction is W ≧ δ / tan
θ is set to satisfy the relationship. By this, the inner corner 33a of the toothed belt 30 in the belt width direction of the right-hand helical set 33 engages with the valley 42c of the tooth 42 of the toothed pulley 40 in the belt width direction. ,
The pair of left and right helical teeth 32, 33 of the toothed belt 30 and the toothed teeth 42 of the toothed pulley 40 come into close contact with each other, and the one-side contact is eliminated.

Therefore, the toothed belt 30 of the present embodiment
In this case, even if there is a phase deviation δ in the longitudinal direction of the belt between the pair of left and right helical teeth 32, 33, one-sided contact generated between the teeth of the toothed belt 30 and the toothed teeth of the toothed pulley 40. Automatically disappears. As a result, there is no possibility that the power which can be transmitted is reduced due to the one-side contact, and the durability of the toothed belt 30 is not reduced. Further, in the toothed belt 30 of the present embodiment, a pair of left and right helical teeth 3
Since it is permissible that the phase deviation δ in the belt longitudinal direction is generated between the belts 2 and 33, the mold used for producing the toothed belt 30 of the present embodiment is manufactured at low cost, and the production cost of the toothed belt 30 is prevented from increasing. can do.

Experimental Example Next, the results of a test performed using the above-described toothed pulley and toothed belt will be described with reference to FIG.

At this time, the tooth pitch of the toothed pulley and the toothed belt is 10 mm, the inclination angle θ of the tooth trace is 12 degrees, and the toothed pulley is intentionally out of phase in the circumferential direction δ = 1. Millimeters were provided. Also, W = 1 / tan1 at the center in the width direction of the toothed belt.
A gap of 2 = 4.7 mm was formed, and the magnitude of the load torque when tooth skipping occurred when torque was applied to the pulley was measured.

As a result, as shown in FIG. 7, when the tooth jump torque in a case where there is no phase deviation in both the toothed belt and the toothed pulley is represented by 100, the pulley has a phase deviation of 1 mm. In this case, the magnitude of the tooth jump torque when no gap was provided at the center in the width direction of the belt was 46. On the other hand, the tooth jump torque when a gap of W = 4.7 mm was provided at the center in the width direction of the belt was 92, and the effect of the toothed belt according to the present invention could be confirmed.

As mentioned above, one embodiment of the toothed pulley and the toothed belt according to the present invention has been described in detail. However, the present invention is not limited to the above-described embodiment, and various modifications are possible. Needless to say. For example, in the above-described embodiment, the toothed belt according to the present invention is combined with the conventional toothed belt, and the toothed belt according to the present invention is combined with the conventional toothed pulley. It goes without saying that the toothed pulley and the toothed belt can be combined. Further, in the above-described embodiment, a gap at the center in the width direction is formed in the toothed pulley or the toothed belt itself in which phase deviation occurs, but the toothed pulley or the toothed belt in which phase deviation occurs. A gap can also be formed at the center in the width direction of the other party combined with the above.

[0040]

As is clear from the above description, the toothed pulley and the toothed belt according to the present invention have a pair of left and right helical teeth symmetrical in the width direction, and have a gap of a predetermined dimension in the width direction. Are opened so as to face each other, so that even if there is a phase deviation between the pair of left and right helical teeth, the teeth between the teeth of the toothed pulley and the teeth of the toothed belt which are combined with each other. There is no one-sided hit. As a result, there is no possibility that the power that can be transmitted due to the one-sided contact is reduced and the durability of the toothed belt is not reduced. Further, since the phase deviation between the pair of left and right helical teeth can be tolerated, a mold for producing the toothed pulley and the toothed belt is manufactured at low cost, and the production cost of the toothed pulley and the toothed belt increases. Can be prevented.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a part of a toothed pulley and a toothed belt of a first embodiment according to the present invention.

FIG. 2 is an enlarged front view of a main part of the toothed pulley shown in FIG.

FIG. 3 is an enlarged front view of a main part schematically showing the operation of the toothed pulley shown in FIG. 1;

FIG. 4 is a perspective view showing a part of a toothed pulley and a toothed belt of a second embodiment according to the present invention.

FIG. 5 is an enlarged front view of a main part of the toothed pulley shown in FIG. 4;

FIG. 6 is an enlarged front view of an essential part schematically showing the operation of the toothed pulley shown in FIG. 4;

FIG. 7 is a table showing experimental results of the toothed pulley and the toothed belt according to the present invention.

FIG. 8 is a perspective view showing a part of a conventional pulley with a toothed tooth and a belt with a toothed tooth.

FIG. 9 is an enlarged front view of a main part of the pulley with toothed teeth shown in FIG. 8;

FIG. 10 is an enlarged front view of a main part schematically showing the action of the pulley with mountain teeth shown in FIG. 9;

FIG. 11 is an enlarged front view of an essential part of the belt with mountain teeth shown in FIG. 8;

FIG. 12 is an enlarged front view of a main part schematically showing the operation of the belt with toothed teeth shown in FIG. 11;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Conventional pulley with a toothed tooth 2 Conventional belt with a toothed tooth 3 Pulley peripheral surface 4 Peak tooth 5 Belt base 6 Peak tooth 10 Pulley with toothed teeth of one embodiment according to the present invention 11 Pulley peripheral surface 12, 13 helical set Reference Signs List 14 gap 15, 16 flange 20 toothed belt 21 belt base 22 mountain tooth 30 toothed belt of one embodiment according to the present invention 31 belt base 32, 33 helical set 34 gap 40 toothed pulley 41 pulley outer peripheral surface 42 mountain Teeth 43,44 flange

Claims (4)

[Claims] 1. A toothed pulley used for power transmission in combination with a toothed belt, wherein a pair of left and right helical teeth symmetrical in the width direction of the pulley are separated from each other by forming a predetermined gap in the width direction. A toothed pulley, which is disposed so as to face each other. 2. The predetermined dimension of the gap is W, the inclination angle of the teeth of the pair of left and right helical teeth is θ, and the phase deviation between the pair of left and right helical teeth in the circumferential direction of the pulley is δ. And when
2. The toothed pulley according to claim 1, wherein the value of W is set so as to satisfy a relationship of W ≧ δ / tanθ. 3. 3. A toothed belt used for power transmission in combination with a toothed pulley, wherein a pair of left and right helical teeth are bilaterally symmetrical in the belt width direction with a gap of a predetermined dimension opened in the belt width direction. A toothed belt characterized by being arranged to face each other. 4. A predetermined dimension of the gap is W, an inclination angle of a tooth trace of the pair of left and right helical teeth is θ, and an amount of phase deviation between the pair of left and right helical teeth in the longitudinal direction of the belt is δ. When you do
The toothed belt according to claim 3, wherein the value of W is set so as to satisfy a relationship of W ≧ δ / tan θ.