KR102373377B1 - double sided toothed belt - Google Patents

Abstract

The present invention is a double-sided toothed belt having a plurality of inner tooth portions arranged at a predetermined pitch along the belt longitudinal direction on the inner peripheral side of the belt, and a plurality of outer tooth portions arranged at a predetermined pitch along the belt length direction on the outer peripheral side of the belt In the above, the pitch of the plurality of inner tooth portions and the pitch of the plurality of outer tooth portions are the same, and the positions of the inner tooth portion and the outer tooth portion in the belt longitudinal direction coincide, and the inner tooth portion It relates to a double-sided toothed belt, characterized in that the tooth shape of the portion and the outer toothed portion are non-rotating.

Description

double sided toothed belt

The present invention relates to improvement of a double-sided toothed belt.

A double-sided toothed belt having toothed portions on both surfaces has inner and outer toothed portions of a predetermined pitch along the belt longitudinal direction, and a core wire is interposed between the inner and outer toothed portions. (介在), it consists of a configuration in which the sawtooth portion of both inner and outer teeth portion and the sawtooth bottom portion of the inner and outer periphery are coated with sawtooth cloth. Separate pulleys are engaged with the inner toothed portion and the outer toothed portion of the double-sided toothed belt, respectively, and a driving force is transmitted from the drive pulley to the plurality of pulleys.

For example, in Fig. 1 of Patent Document 1, a general double-sided toothed belt conventionally systematized in the market is disclosed. In this double-sided toothed belt, the inner tooth part and the outer tooth part of substantially the same shape are arrange|positioned at predetermined pitch in the belt longitudinal direction, respectively. Moreover, the arrangement pitch of the inner toothing portion and the outer toothing portion is the same, and further, the inner toothing portion and the outer toothing portion are at the same position in the belt longitudinal direction. That is, the inner toothed portion and the outer toothed portion are in a positional relationship opposite to each other by sandwiching the core wire.

As described above, in a general double-sided toothed belt with the same shape and the same size, the inner and outer teeth arranged on the inner and outer peripheral surfaces of the belt, respectively, the size of the power transmitted by one tooth on the inner and outer periphery (referred to as electric capacitance) will be the same. However, there has been a concern that such a belt is difficult to be applied to a synchronous transmission belt system having different loads and functions in the inner and outer periphery transmission systems depending on the purpose of use. In order to cope with this, belts having different pitches and sizes of teeth on the inner and outer periphery have been proposed.

For example, in Fig. 2 of Patent Document 1, there is disclosed a double-sided toothed belt in which the pitch of the inner tooth is larger than the pitch of the outer tooth, and the inner tooth is larger than that of the outer tooth. Due to the difference in pitch between the inner and outer toothed portions, the positions of the inner and outer toothed portions in the belt longitudinal direction do not necessarily coincide. Further, Patent Document 2 discloses a double-sided toothed belt in which the pitch of the outer tooth portions is larger than the pitch of the inner tooth portions, and the outer tooth portion is larger than the inner tooth portion. Also in the belt of this patent document 2, the position of the inner tooth part and the outer tooth part in the belt longitudinal direction does not necessarily correspond.

Patent Document 1: Japanese Publication No. 58-40642 Patent Document 2: Japanese Patent Laid-Open No. Hei 10-132032

However, in the belt as disclosed in Fig. 2 of Patent Document 1 or Patent Document 2, since the positions of the inner and outer teeth in the belt longitudinal direction do not necessarily coincide, the bending rigidity of the belt as a whole is become big Therefore, since the meshing|engagement when a belt is wound around a pulley becomes bad, the vibration of the belt accompanying meshing|engagement of a belt and a pulley becomes large, and there exists a possibility that a belt may deteriorate prematurely.

Further, in Patent Document 2, the occurrence of the above problem is suppressed by varying the rubber hardness of the toothed portion on the inner and outer periphery of the belt, but there is a concern that the problem is not sufficiently solved. In addition, since it is essential to vary the rubber hardness on the inner and outer periphery, there is also a disadvantage that the process increases in the manufacturing stage and the manufacturing cost increases.

An object of the present invention is to obtain a double-sided toothed belt capable of varying the transmission capacity on the inner and outer periphery of the belt while matching the positions of the inner and outer toothed portions in the belt longitudinal direction.

The double-sided toothed belt of the present invention includes a plurality of inner toothed portions arranged at a predetermined pitch along the belt longitudinal direction on the inner peripheral side of the belt, and a plurality of outer toothed portions arranged at a predetermined pitch along the belt longitudinal direction on the outer peripheral side of the belt. In the double-sided toothed belt having a portion, the pitch of the plurality of inner tooth portions and the pitch of the plurality of outer tooth portions are the same, and the positions of the inner tooth portion and the outer tooth portion in the belt longitudinal direction coincide and the sawtooth shapes of the inner toothed portion and the outer toothed portion are non-reciprocal.

According to the above configuration, in the double-sided toothed belt, since the tooth shapes of the inner tooth portion and the outer tooth portion are non-linear, the meshing state between the tooth portion and the pulley on the inner and outer periphery of the belt is different from each other, and on the inner and outer periphery, the teeth In addition to the negative durability, the transmission capacity is also different.

Moreover, the tooth pitch of an inner tooth|tooth part and an outer tooth|tooth part is the same, and the position in the belt longitudinal direction corresponds with an inner tooth|tooth part and an outer tooth|tooth part. In addition, "the pitch of the teeth" means the thing of the arrangement|positioning spacing of the teeth along the pitch line (center line of a core line) of a belt (the space|interval of the center lines of the belt longitudinal direction of mutually adjacent tooth|tooth parts). In addition, "the position in the belt longitudinal direction coincides with the inner tooth part and the outer tooth part" means that the center line in the belt longitudinal direction coincides with the inner tooth part and the outer tooth part. If the offset amount of the center line in the longitudinal direction of the belt between the inner and outer teeth is within the range of less than 5% of the tooth pitch, the positions of the inner and outer teeth coincide in the longitudinal direction of the belt. It is good to consider In this configuration, the position in the belt longitudinal direction of the tooth bottom, which is a portion between the tooth portions, inevitably coincides with the inner and outer periphery, and the bending rigidity of the belt becomes small as a whole. Accordingly, the flexibility of the belt is improved, and since it is smoothly wound around the pulley, meshing between the belt and the pulley at the time of power transmission becomes smooth. Thereby, since vibration of the belt accompanying meshing|engagement of a belt and a pulley becomes small and it is hard to deteriorate a belt, durability of a belt improves.

That is, if the double-toothed belt having the above configuration is adopted, it can be applied to a synchronous transmission belt system with different transmission capacities on the inner and outer periphery of the belt while securing the interlocking properties of the belt and the pulley during power transmission and the durability of the belt. Do.

In the double-sided toothed belt of the present invention, it is preferable that the shape of the side surfaces of the inner toothed portion and the outer toothed portion are different from each other.

According to the above configuration, the side surface of the toothed portion of the pulley is in contact with the side surface of the toothed portion of the belt, and power is transmitted. Therefore, by varying the side shape of the toothed portion on the inner and outer periphery of the belt, it is possible to vary the meshing state between the inner toothed portion and the outer toothed portion with the pulley, and by extension, the transmission capacity. In addition, in this invention, "the side surface of a toothed part" refers to the side surface in the belt longitudinal direction of a toothed part.

As for the double-sided toothed belt of this invention, the side surface of one toothed part among the said inner tooth|tooth part and the said outer tooth|tooth part may be flat, and the side surface of the other toothed part among them may be a curved surface.

According to the above configuration, it is possible to change the engagement state of the pulley in the inner toothed portion and the outer toothed portion by making the side surface shape of one toothed portion a flat surface and the other toothed portion having a curved surface.

It is preferable that the double-sided toothed belt of this invention is a convex-shaped curved surface in which the side surface of the said other toothed part bulged outward.

According to this configuration, since the other toothed portion is a convex curved surface with the side surface bulging outward, engagement with the toothed portion of the pulley is smooth. Accordingly, the bending fatigue resistance of the core wire is improved in the running of the belt. In addition, in the other toothed portion, since the stress from the pulley meshing with the other toothed portion is difficult to concentrate on the distal portion, the shear stress of the tooth is small, and the durability of the toothed portion is small. This improves.

Moreover, since the meshing|engagement of the other toothed part and the pulley is smooth, the flying phenomenon of the other toothed part is hard to occur.

Further, since the meshing between the other toothed portion and the pulley is smooth, the vibration on the other toothed portion side of the belt is small, so the quietness is large on the other toothed portion side of the belt , speed unevenness is small, and high-precision positioning is possible. From the above, the transmission ability of the toothed part on the other side of the belt becomes high.

Further, since the other toothed portion engages smoothly with the pulley, the transmission capacity of the other toothed portion is large. Thereby, it is possible to transmit power even if the number of teeth engaging the other side of the belt and the pulley is small. Thereby, the pulley meshing with the toothed part on the other side of the belt becomes small diameter, and it is possible to achieve saving space and cost reduction.

In the double-sided toothed belt of the present invention, the side surface of the other toothed portion may include a circular arc surface.

At this time, the side surface of the other toothed portion may have a surface shape in which a plurality of arc surfaces are connected to each other.

In the double-sided toothed belt of the present invention, the other toothed portion may be the outer toothed portion.

According to the above configuration, since the outer toothed portion has a toothed shape with a high transmission capacity, it is possible to transmit power even if the number of meshing teeth between the outer toothed portion and the pulley meshing with the outer toothed portion is small.

In the double-sided toothed belt of the present invention, in the inner toothed portion and the outer toothed portion, it is preferable that the hardness of the rubber constituting the toothed portion is the same.

According to this configuration, since the hardness of the rubber constituting the toothed portion is the same in the inner toothed portion and the outer toothed portion of the belt, it is sufficient to prepare one type of rubber for manufacturing the belt. , and it is possible to suppress the manufacturing cost of the belt.

As described above, in the present invention, it is possible to obtain a double-sided toothed belt capable of varying the transmission capacity on the inner and outer periphery of the belt while matching the positions of the inner and outer toothed portions in the belt longitudinal direction.

[Fig. 1] Fig. 1 is a schematic configuration diagram of a belt system of the present invention.
[Fig. 2] Fig. 2 is a partially enlarged cross-sectional view of the double-sided toothed belt according to the embodiment of the present invention in a cross section including the belt longitudinal direction.
[Fig. 3] Fig. 3 is a partially enlarged view of Fig. 2;
[Fig. 4] Fig. 4 is a diagram showing that the configuration of Figs. 4 (b) and (c) can be changed by applying the present invention to Fig. 4 (a) in the configuration example of the belt system.
[Fig. 5] Fig. 5 is a diagram showing that the configuration of Fig. 5(b) can be changed by application of the present invention to Fig. 5(a) in another configuration example of the belt system.
[Fig. 6] Fig. 6 is a partially enlarged cross-sectional view of a double-sided toothed belt of a modified example of the present embodiment in a cross section including the belt longitudinal direction.
[Fig. 7] Fig. 7 is a diagram showing that the configuration of Fig. 7 (b) can be changed by applying the present invention to Fig. 7 (a) in the configuration example of the belt system.
[Fig. 8] Fig. 8 is a partially enlarged cross-sectional view of the double-sided toothed belt of Comparative Example 1 in a cross section including the belt longitudinal direction.
[Fig. 9] Fig. 9 is a partially enlarged cross-sectional view of the double-sided toothed belt of Comparative Example 2 in a cross section including the belt longitudinal direction.

Hereinafter, the belt system 1 and the double-toothed belt 6 of an example of embodiment of this invention are demonstrated.

(belt system (1))

The belt system 1 of this embodiment is applied to the belt system equipped with the general industrial machine. As shown in Fig. 1, the belt system 1 is composed of a plurality of pulleys 2 to 5 and a double-sided toothed belt 6, and one double-sided toothed belt 6 includes a plurality of pulleys 2 to 5) is wound and hung. A driving timing pulley 2 , an idle timing pulley 3 , and a driven timing pulley 4 are arranged on the inner periphery side of the belt system 1 , and a driven timing pulley 5 is arranged on the outer periphery side of the belt system 1 . has been 1 to 3, the double-sided toothed belt 6 has a plurality of inner toothed portions 8 arranged along the belt longitudinal direction on the inner peripheral side of the belt 6, and the belt longitudinal direction on the outer peripheral side of the belt It has a plurality of externally toothed portions 9 arranged along the .

As shown in Fig. 1, in the belt system 1 at the time of power transmission, the toothed grooves 11 of the pulleys 2-5 and the toothed portions 8 and 9 of the double-sided toothed belt 6 are is engaged, and the side surface 12 of the toothed portion of the pulleys 2 to 5 is in contact with the side surface 82, 92 of the toothed portion 8,9 of the belt 6 to transmit power from the pulley 2 to the pulley 4 , 5) is transmitted. That is, the belt system 1 of this embodiment is a synchronous transmission system. The toothed groove 11 of the pulleys (2-4) and the inner toothed portion 8 of the double-sided toothed belt 6 are engaged, the toothed groove 11 of the pulley 5 and the outer tooth of the double-sided toothed belt 6 The portion 9 engages.

(Double-toothed belt (6))

2 and 3, the double-sided toothed belt 6 of the present invention is an endless belt, and includes a core wire 7 embedded in the body portion of the belt 6 and , A plurality of inner toothed portions 8 arranged at a pitch P1 along the belt longitudinal direction on the inner peripheral side of the belt 6, and a plurality of outer toothed portions arranged at a pitch P2 on the outer peripheral side of the belt 6 along the belt lengthwise direction It has (9) and a toothed cloth (10) covering the inner toothed portion (8) and the outer toothed portion (9). The pitch P1 of the inner toothed portion 8 and the pitch P2 of the outer toothed portion 9 are the same, and the positions of the inner toothed portion 8 and the outer toothed portion 9 in the belt longitudinal direction coincide. In other words, the inner toothed portion 8 and the outer toothed portion 9 are in a positional relationship opposite to each other with the core wire 7 interposed therebetween. Further, the positions of the tooth bottoms 84 and 94 in the portion between the toothed portions 8 and 9 also coincide in the longitudinal direction of the belt.

(Core wire (7))

2 and 3, the core wire 7 is embedded in the main body portion of the double-toothed belt 6, and exists in the vicinity of the center of the belt 6 in the belt thickness direction. The core wire 7 is obtained by twisting filaments of 5 to 9 μm of E glass or high strength glass with each other and treated with a protective agent made of a rubber compound or an adhesive, such as RFL solution. In addition, the core wire 7 may be other than the above, and as an organic fiber, a filament of 0.5 to 2.5 denier of para-aramid fiber (trade name: Kevlar, Technora) having a small elongation with respect to stress and high tensile strength is twisted with each other, A braided cord treated with an adhesive between an RFL solution, an epoxy solution, an isocyanate solution and a rubber compound may be used. Moreover, for example, the wire diameter of the core wire 7 is about 0.8 mm.

(Inner tooth (8) and outer tooth (9))

Both the inner toothed portion 8 and the outer toothed portion 9 are formed of a rubber material mainly composed of chloroprene rubber or the like. Moreover, in this embodiment, the rubber which comprises the inner tooth part 8 and the outer tooth part 9 has the same component and the same hardness. For example, rubber hardness is about 75 in durometer A hardness based on JISK6253:2012. The details of the shapes of the inner toothed portion 8 and the outer toothed portion 9 will be described later.

(Sprocket (10))

As shown in Figs. 2 and 3, the toothed cloth 10 covers the entire surface of the inner toothed portion 8 and the outer toothed portion 9 along the shape of the double-sided toothed belt 6 . In this embodiment, as the sawtooth fabric 10, the warp (belt width direction) is 6 nylon, and the weft yarn (belt length direction) is 6 nylon wool. Canvas (帆布), a twill weave, is being used. In addition, some of the elastic urethane yarns having elasticity may be used for the weft yarns. What the said canvas was immersed with RFL liquid was used as the sawtooth cloth 10. For example, the thickness of the sawtooth cloth 10 is about 0.2 m. In addition, the sawtooth cloth 10 is not limited to the above. The canvas used as the sawtooth cloth 10 is polyester, aramid fiber, etc., and may be independent or mixed.

(The sawtooth shape of the inner toothed portion 8 and the outer toothed portion 9)

By the way, as shown in Figs. 2 and 3, the sawtooth shapes are different from each other in the inner toothed portion 8 and the outer toothed portion 9. As shown in Figs. Specifically, in this embodiment, the side shape of the toothed portions 8 and 9 of the belt 6 in contact with the side surface 12 of the toothed groove 11 of the pulleys 2 to 5 is defined as the inner toothed portion ( 8) and the outer tooth part 9 are different from each other. In the inner toothed portion 8, the side surface 82 is formed in a flat surface, and with respect to the outer toothed portion 9, the side surface 92 is formed in a curved surface. Hereinafter, the details of the sawtooth shapes of the inner toothed portion 8 and the outer toothed portion 9 will be described.

(The tooth shape of the inner tooth part (8))

As shown in Figs. 2 and 3, the sawtooth shape of the inner toothed portion 8 is a shape called a T-tooth shape. It has a shape connected by a plane. The tooth line part 81 which is the front-end|tip of the inner tooth part 8 is a flat surface, and the two side surfaces 82 are planar together. The toothed portion 83 of the inner toothed portion 8 is connected to the toothed bottom 84 with a curved surface having a certain curvature. Moreover, the ridge line between the tooth line part 81 of the inner tooth|tooth part 8 and the side surface 82 is chamfered.

If an example of the dimensions of the inner tooth portion 8 is enumerated, for example, pitch P1 = 5 mm (2.0 to 20 mm), tooth height H1 = 1.2 mm (0.7 to 5 mm), tooth width W1 = 2.65 mm (1.5) ~10.15 mm), the tooth angle β1 = 40°, which is an angle formed by the both side surfaces 82 in the belt longitudinal direction of the inner toothed portion 8 .

(Tooth shape of the outer tooth part 9)

2 and 3, the sawtooth shape of the outer toothed portion 9 is a shape called a STPD tooth shape, and has a shape in which two side surfaces each of a curved surface (arc surface) are connected by a flat surface. The tooth line portion 91 of the external toothed portion 9 is a flat surface, and both side surfaces 92 are both convex curved surfaces swollen outward. In more detail, the side surface 92 has the shape which connected two circular arcs smoothly in the cross section including the belt longitudinal direction. In addition, the toothed portion 93 of the outer toothed portion 9 is connected to the toothed bottom 94 as a curved surface having a constant curvature.

Listing examples of dimensions of the outer toothed portion 9, for example, the arrangement pitch P2 of the outer toothed portion 9 is the same as the arrangement pitch P1 of the inner toothed portion 8, and the pitch P2 = 5 mm (2.0-20 mm), tooth height H2 = 1.91 mm (0.76 to 5.30 mm), and tooth width W2 = 3.25 mm (1.30 to 9.10 mm). The outer toothed portion 9 has a larger tooth height, a larger tooth width, and a larger size of the toothed portion than the inner toothed portion 8 .

(Manufacturing method of double-toothed belt 6)

The said double-sided toothed belt 6 can be manufactured as follows, for example.

1. Wind the sawtooth cloth (10) along the outer circumferential surface of the mold with grooves, and spirally wind the core wire (7) on it, and again on it, an unvulcanized rubber sheet and sawtooth cloth. (10) is wound, and the thus-obtained belt molded body is heated and pressurized to prepare an uncured green body.

2. The preform removed from the mold with the groove is hung on two pulleys with adjustable distance between the shafts, and the preform is pressed by a press mold made of a mold having a pair of inside and outside teeth to form an inner toothed part (8) and The outer toothed portion 9 is molded, the vulcanized portion is moved, and the next inner toothed portion 8 and the outer toothed portion 9 are formed and vulcanized repeatedly.

(action effect)

As shown in Fig. 2, in the double-sided toothed belt 6 of the present embodiment, the inner toothed portion 8 and the outer toothed portion 9 have the same arrangement pitch, and the inner toothed portion 8 and the outer toothed portion 9 are the same. ) coincides with the position (center line) in the belt longitudinal direction, but the inner toothed portion 8 and the outer toothed portion 9 have different side surface shapes. Specifically, as shown in Figs. 2 and 3, the side surface 82 of the inner toothed portion 8 is flat, and the side surface 92 of the outer toothed portion 9 is a convex curved surface that bulges outward. If the side surface 92 of the outer toothed portion 9 is a convex curved surface, the side surface 12 of the toothed groove 11 of the pulley 5 is located on the curved side surface 92 compared to the case where the side surface 92 is flat. ), when the pulley 5 rotates while continuously contacting, the meshing becomes smooth, and smooth power transmission becomes possible on the outer peripheral side of the belt 6 . Accordingly, it can be said that the outer periphery of the belt 6 has a high transmission capacity because the outer toothed portion 9 has a curved surface bulging outward. Actually, the transmission capacity of the outer toothed portion 9 is about twice that of the inner toothed portion 8 . In other words, in a belt system in which power is to be transmitted particularly efficiently to the outer peripheral side of the belt, the double-toothed belt 6 of this embodiment is optimal.

Moreover, as shown in FIG. 2, in the double-sided toothed belt 6 of this embodiment, the tooth pitch of the inner toothed part 8 and the outer toothed part 9 is the same, and the inner toothed part 8 and the outer toothed part. In (9), the position (center line) in the belt longitudinal direction coincides. In this configuration, the positions in the belt longitudinal direction of the tooth bottoms 84 and 94, which are portions between the toothed portions 8 and 9 on the inner and outer periphery inevitably, also coincide, and the bending rigidity of the belt is small as a whole. As a result, the flexibility is improved, and the belt is gently wound around the pulleys 2 to 5. For this reason, the meshing|engagement of the belt 6 and the pulleys 2-5 at the time of power transmission becomes smooth. Thereby, the vibration of the belt 6 accompanying meshing|engagement of the belt 6 and the pulleys 2-5 becomes small, and since it is hard to deteriorate a belt, durability of the belt 6 improves.

In addition, as shown in Figs. 2 and 3, the double-sided toothed belt 6 of the present embodiment is a double-sided toothed belt 6 because the side surface 92 of the outer toothed portion 9 is a convex curved surface bulging outward. The engagement between the outer toothed portion 9 of the and the toothed portion of the pulley 5 is smooth. As a result, in the outer toothed portion 9 , since the stress from the pulley 5 is difficult to concentrate on the diametrical portion 93 , the shear stress of the outer toothed portion 9 is small and the outer toothed portion 9 . improve the durability of

Moreover, since the meshing|engagement of the outer tooth part 9 and the toothed part of the pulley 5 is smooth, the flying phenomenon of the outer tooth part 9 does not occur easily at the time of power transmission.

In addition, since the meshing between the outer toothed portion 9 and the toothed portion of the pulley 5 is smooth, the vibration on the outer peripheral side of the belt 6 is small, so the quietness is large on the outer peripheral side of the belt 6 , speed unevenness is small, and high-precision positioning is possible. From the above, the transmission capability of the outer tooth part 9 of the belt 6 becomes high.

In the double-sided toothed belt 6 of this embodiment, since the hardness of the rubber constituting the toothed portion is the same in the inner toothed portion 8 and the outer toothed portion 9, for manufacturing the belt 6, one type of rubber What is necessary is just to prepare, and it is possible to suppress the manufacturing cost of the belt 6 .

The double-sided toothed belt 6 of the present embodiment described above is a convex curved surface in which the side surface 92 of the outer toothed portion 9 swells outward, and has a transmission capacity higher than that of the inner toothed portion 8 . By employing this belt 6, in the belt system 1, it becomes possible to make various changes regarding the layout and the like.

Since the transmission capacity per tooth of the outer toothed portion 9 is high, even if the number of teeth of engagement between the outer toothed portion 9 and the pulley 5 is small, it is possible to transmit a desired power. Therefore, for example, if the double-toothed belt 6 of this embodiment is employed for the belt system 1 as shown in Fig. 4(a), the diameter of the pulley 5 as shown in Fig. 4(b). It becomes possible to reduce the cost associated with the belt system 1 by reducing the size of the belt system and making the entire belt system compact.

Alternatively, as shown in Fig. 4(c), it is possible to shift the position of the pulley 5 to the outside. Thereby, it is possible to widen the space inside the belt system 1, and it is possible to arrange a system structural member separate from the system structural member of the belt system 1 inside the belt system 1 do.

Alternatively, if the double-toothed belt 6 of this embodiment is adopted for the belt system 1 as shown in Fig. 5 (a), the position of the pulley 4 is shifted inward as shown in Fig. 5 (b). It becomes possible to put Thereby, the whole belt system can be made compact, and it becomes possible to reduce the cost related to the belt system 1 .

(variation example)

About the shape of the inner tooth part 8 and the outer tooth part 9, it is not limited to the thing of the said embodiment, It can change suitably as follows.

(1) The convex curved surface of the outer tooth part 9 is not limited to the circular arc surface. For example, a part of a parabola, an elliptical arc surface, etc. may be sufficient.

The side shape of the toothed portions 8 and 9 is not limited to a combination of a flat surface (inner toothed portion 8) and a convex curved surface (outer toothed portion 9) as in the above embodiment.

(2) Both the side surface of the inner toothed portion and the side surface of the outer toothed portion are curved surfaces, and the curvatures of both may be different. The transmission capacity also changes when the curvature of the curved surface is different.

(3) Both the side surface of the inner toothed portion and the side surface of the outer toothed portion are flat, and the inclination angles with respect to the tooth bottoms 84 and 94 (core wire 7) may be different.

(4) In the above embodiment, the tooth line portions 81 and 91 of the inner toothed portion 8 and the outer toothed portion 9 were flat surfaces, but the toothed portion may be a curved surface such as an arc surface.

(5) In the above embodiment, although the hardness of the rubber constituting the inner toothed portion 8 and the outer toothed portion 9 is the same, the hardness of the rubber constituting the inner toothed portion and the outer toothed portion may be different.

(6) In the above embodiment, the side surface 92 of the outer toothed portion 9 has a high transmission capacity and is formed as a convex curved surface that swells outward, but as shown in Fig. 6, the inner toothed portion 8 and the outer The shape of the side surface of the toothed portion 9 may be reversed from that of the above embodiment. Specifically, the side surface 282 of the inner toothed portion 28 may be a circular arc surface, and the side surface 292 of the outer toothed portion 29 may be flat. In this way, by making the sawtooth shape of the inner and outer toothed portions 28 and 29 reverse to that of the above embodiment, the transmission capacity of the inner toothed portion 28 becomes high.

As shown in Fig. 6, in the double-sided toothed belt 26 of this modification, the inner toothed portion 28 and the outer toothed portion 29 have the same arrangement pitch, and the inner toothed portion 28 and the outer toothed portion 29 are the same. Although the positions in the longitudinal direction of the belt coincide with each other, the side surfaces of the inner toothed portion 28 and the outer toothed portion 29 are different from each other. Specifically, as shown in Fig. 6, the side surface 282 of the inner toothed portion 28 is a convex curved surface that swells outward, and the side surface 292 of the outer toothed portion 29 is flat. When the side surface 282 of the inner toothed part 28 is a convex curved surface, as shown in FIGS. 6 and 7, compared to the case where the side surface 282 is flat, the pulleys 22 to 24 are attached to the curved side surface 282. When the pulleys 22 to 24 rotate while the side surfaces of the toothed grooves of , contact continuously, the meshing becomes smooth, and smooth power transmission is possible on the inner periphery of the belt 26 . Therefore, since the inner toothed portion 28 has a curved surface that swells outward, it can be said that the inner peripheral side of the belt 26 has a high transmission capacity. Actually, the transmission capacity of the inner toothed portion 28 is about twice that of the outer toothed portion 29 . In other words, in a belt system in which power is to be transmitted particularly efficiently to the inner peripheral side of the belt, the double-toothed belt 26 of this modification is optimal.

Since the transmission capacity per tooth of the inner toothed portion 28 is high, even if the number of teeth of engagement between the inner toothed portion 28 and the pulleys 22 to 24 is small, it is possible to transmit a desired power. Therefore, for example, when the double-sided toothed belt 26 of this embodiment is employed for the belt system 21 as shown in Fig. 7(a), as shown in Fig. 7(b), the pulleys 22 to 24 are It becomes possible to reduce the diameter of the belt system 21 to make the entire belt system compact, and to reduce the cost associated with the belt system 21 .

Example

Next, the double-sided toothed belts according to Examples 1 and 2 and Comparative Examples 1 and 2 were produced, and the transmission capacity was compared and the belt durability running test was performed.

(Configuration of belt)

For the double-sided toothed belts (specimen) of Examples 1 and 2 and Comparative Examples 1 and 2, the pitches of the inner and outer teeth, and the tooth shapes of the inner and outer teeth are shown in Table 1 It was set as the shown structure. In addition, in Table 1, the tooth height and tooth width of the inner tooth part and the outer tooth part in each belt (specimen) are also shown.

As another common matter, each double-sided toothed belt (specimen) was made into the structure shown below.

(1) Belt width: 10mm

(2) Belt circumference: 385 mm

(3) Core wire: Table 2 shows the specifications of the core wire. In addition, the composition of the RFL liquid used for the adhesion process of a core wire is shown in Table 3.

(4) Composition of rubber material (unvulcanized rubber sheet) constituting the toothed portion: Table 4 shows. The rubber material constituting the toothed portion is a rubber composition containing chloroprene rubber as a main component.

(5) Rubber hardness of tooth part (based on JIS K6253:2012): It is about 75 in durometer A hardness.

(6) Sawtooth cloth: Table 5 shows the structure of the sawtooth cloth. For Examples 1, 2, and Comparative Example 1, toothed cloth A was used for both the belt inner circumference side and the belt outer circumference side. In Comparative Example 2, toothed cloth A was used on the inner peripheral side of the belt, and toothed cloth B was used on the outer peripheral side of the belt.

(Method of manufacturing the belt)

(1) In accordance with the procedure described in the above embodiment, Examples 1 and 2 and Comparative Examples 1 and 2 of the double-sided toothed belts (specimen) having the above configuration were manufactured. The vulcanization was performed by heating and pressurizing the green body at 165°C (surface temperature of the press die) and a surface pressure of 5.0 MPa for 20 minutes.

(2) of the double-sided toothed belt (specimen) manufactured by the above, a partially enlarged cross-sectional view in a section including the belt longitudinal direction, Example 1 is Figure 2, Example 2 is Figure 6, Comparative Example 1 is Figure 8 , and Comparative Example 2 are shown in FIG. 9 .

(belt system)

The belt system involved in the evaluation of the embodiment is the same as the belt system 1 described in the above embodiment, and its schematic configuration diagram is substantially the same as that of FIG. 1 .

Here, the number of teeth and pitch diameter of each pulley are shown in Table 6. In addition, the number of teeth meshing with the belt in each pulley is ensured to be 6 or more.

(Assessment Methods)

1. Transmission capacity at the inner and outer circumferences of the belt

The transmission capacity of the inner tooth portion and the transmission capacity of the outer tooth portion are, respectively, in Japanese Industrial Standard JIS SK6372: 1995 (toothed belt for general use), as a reference (how to use the toothed belt for general use) in the separate table (standard transmission capacity table for each tooth type) was read from This separate table is created based on the formula (corresponding to Section 3.3.1 and Equation 7 of the same standard) for calculating the “transmission capacity of the belt”. Here, the rotational speed of the small pulley to be read was set to 1800 rpm, which corresponds to the running conditions in a durability running test to be described later. Table 6 shows the results of the read transmission capacity of the inner toothed portion and the transmission capacity of the outer toothed portion. In addition, the exponent when the transmission capacity of the toothed portion having the T5 tooth shape was set to 100 was written in parentheses.

2. Belt endurance test

Using the double-sided toothed belts (specimen) of Examples 1 and 2 and Comparative Examples 1 and 2, a belt endurance running test was performed under the layout shown in Fig. 1 and running conditions shown in Table 6. In addition, prior to the test, the belt tension before running was measured with a sonic tension meter (Mitsuboshi Corporation, trade name "Doctor Tension Type IV"). Then, the belt endurance running test was started, and the belt tension after running (immediately after reaching the number of bends shown in Table 6 and stopping running) was measured again. Table 6 shows the results of calculating the value of the belt tension retention rate from the tension of each belt before and after running. The higher the value of the belt tension retention ratio, the better the meshing property between the belt and the pulley during power transmission and the bending fatigue resistance of the core wire. In addition, failure of the belt during running was observed, and the failure phenomenon was described in the case of occurrence of unfavorable conditions such as tooth chafing, cracks in the diaphragm, and jumping.

(Evaluation results)

Table 6 shows the transmission capacity at the inner and outer periphery of the belt and the evaluation results of the belt endurance running test. Evaluation (judgment) was made into following A or B.

That is, it is possible to vary the transmission capacity on the inner and outer periphery of the belt. In addition, as a result of the belt endurance running test, when there is no belt failure and the belt tension retention rate is 63% or more, the belt and pulley during power transmission A determination A was made on the assumption that it was considered applicable to a synchronous transmission belt system having a different transmission capacity at the inner and outer periphery of the belt while securing the interlocking properties and durability of the belt.

When it is not possible to vary the transmission capacity on the inner and outer periphery of the belt, or, as a result of the belt endurance running test, when there is a failure of the belt, or when there is no belt failure, the belt tension retention rate does not reach 63% In the case of the synchronous transmission belt system, it was determined that it was not considered applicable to a synchronous transmission belt system having a different transmission capacity on the inner and outer periphery of the belt while securing the meshing property of the belt and the pulley during power transmission and the durability of the belt.

According to the evaluation results in Table 6, in Examples 1 and 2, there was no problem in the belt tension retention rate after endurance running, the meshing property of the belt and the pulley during power transmission, and the bending fatigue resistance of the core wire were good, and the belt There was no failure, and the durability of the belt was good.

As for Example 1, the transmission capacity (367W) of the outer toothed portion (S5M toothed type) is about twice the transmission capacity (183W) of the inner toothed portion (T5 toothed type), so it is particularly efficient on the belt outer periphery side It is assumed that this is because power transmission has been performed. As for Example 2, the transmission capacity (367W) of the inner toothed portion (S5M toothed type) is about twice the transmission capacity (183W) of the outer toothed portion (T5 toothed type), so that power is transmitted particularly efficiently from the inner periphery of the belt It is assumed that this was done.

Comparative Example 1 is a conventional general double-toothed belt, and the meshing property with the pulley is not so smooth, and the transmission capacity (183W) is not so large. , as it is not possible to vary the transmission capacity on the inner and outer periphery of the belt, it was assumed that power transmission was not efficiently performed on the inner periphery of the belt or the outer periphery of the belt to the extent of the cases of Examples 1 and 2. With regard to the durability of the belt, there was no problem in engagement with the pulley under the current running conditions, and there was no problem in practical use.

Comparative Example 2 resulted in the lowest durability of the belt under the current running conditions. In this case, the outer toothed portion has a larger transmission capacity (exponent 111) than the inner toothed portion (T5 toothed type), and is formed in a toothed shape (S2M toothed type) with smooth engagement with the pulley. However, because the pitches of the inner and outer teeth differ, the positions of the inner and outer teeth in the longitudinal direction of the belt do not necessarily coincide. Therefore, as the bending rigidity of the belt is increased as a whole, the meshing property between the belt and the pulley is deteriorated, and it is assumed that the bending fatigue property of the core wire is deteriorated.

Although this invention was demonstrated with reference to the specific embodiment in detail, it is clear to those skilled in the art that various corrections and changes can be added without deviating from the mind and range of this invention.

This application is based on Japanese Patent Application No. 2017-249346 of an application on December 26, 2017, and Japanese Patent Application No. 2018-231301 of an application on December 11, 2018, The content is incorporated herein by reference.

1 belt system
2-5 pulleys
6 double sided toothed belt
7 core wire
8 inner tooth
9 Outer tooth
10 sawtooth

Claims (8)

A plurality of inner toothed portions arranged at a predetermined pitch along the belt longitudinal direction on the inner peripheral side of the belt, and a plurality of outer toothed portions arranged at a predetermined pitch along the belt lengthwise direction on the outer peripheral side of the belt, the inner toothed portion and A double-toothed belt for transmitting a driving force from an interlocking driving pulley to a plurality of other pulleys, comprising:
The pitch of the plurality of inner tooth portions and the pitch of the plurality of outer tooth portions are the same, and the positions of the inner tooth portion and the outer tooth portion in the belt longitudinal direction coincide,
In the inner toothed portion and the outer toothed portion, the hardness of the rubber constituting the toothed portion is the same,
A side surface of one of the inner toothed portion and the outer toothed portion is flat;
The other side of the toothed part is a curved surface including an outwardly inflated arc surface,
The other toothed portion is the outer toothed portion, and the one toothed portion is the inner toothed portion,
Double-sided toothed belt, characterized in that the transmission capacity of the outer tooth portion is larger than the transmission capacity of the inner tooth portion. delete delete delete delete According to claim 1,
Double-sided toothed belt, characterized in that the side surface of the other toothed portion is a surface shape in which a plurality of arc surfaces are connected to each other. delete delete

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