JP3721220B2 - Transmission belt - Google Patents

Description

【００２８】
次に、図３に示す如く、各々のプーリ径がいずれも８５ｍｍのＶプーリからなる駆動及び従動プーリ１１，１２間に上記作製した各ベルトＢを巻き掛け、室温（２０〜３０℃）の雰囲気中で、従動プーリ１２に駆動プーリ１１から離れる方向に１００ｋｇのデッドウェイトをかけかつ従動プーリ１２に所定の伝動負荷をかけた状態で、駆動プーリ１１を４９００ｒｐｍで回転させてベルト走行試験を行い、各ベルトＢの接着ゴム層と圧縮ゴム層及び心線との界面での亀裂発生までのセパレーション寿命を測定した。その結果を下記の表２に示す。
【００２９】
【表２】

【００３０】
この表２から明らかなように、本発明例は比較例に比べ、ベルトのセパレーション寿命が大幅に延びることが判る。尚、比較例３では、粘度が高くなり過ぎて、それ以上カーボンを増量させることができなかったものである。
【００３１】
【発明の効果】
以上説明したように、請求項１の発明によると、伝動用ベルトにおいて、心線が埋設された接着ゴム層を、繊維が混入分散されかつ接着ゴム層のベルト底面側に設けられた圧縮ゴム層と略同等の弾性率を有する高弾性ゴム組成物で構成したことにより、接着ゴム層の圧縮ゴム層及び心線との界面での弾性率の差がなくなり、界面での応力集中による亀裂発生を抑制して伝動用ベルトの高寿命化を図ることができる。
【００３２】
請求項２の発明によると、上記少なくとも接着ゴム層を、ポリマー製造過程のラテックス状態で短繊維が分散されたゴム組成物で構成したことにより、上記圧縮ゴム層と略同等の弾性率の高弾性の接着ゴム層となるのに好適なゴム組成物を具体的に容易に実現することができる。
【００３３】
請求項３の発明によると、短繊維をアラミド繊維、綿繊維、絹繊維等の高弾性率の繊維としたことで、短繊維の混入量を少なくしてゴムのラテックス状態での流動性を確保しながら、接着ゴム層の弾性率を高めることができる。
【００３４】
請求項４の発明によると、短繊維はフィブリル化されて表面積の大きいものとしたことにより、短繊維のゴムとの接着性のより一層の向上を図ることができる。
【図面の簡単な説明】
【図１】 本発明の実施形態１に係るＶベルトの断面図である。
【図２】 実施形態２に係るＶリブドベルトの断面図である。
【図３】 ベルト走行試験装置の概略図である。
【符号の説明】
Ｂ Ｖベルト
Ｂ′ Ｖリブドベルト
１ 心線
２ 接着ゴム層
３，３′ 圧縮ゴム層
４，５ 帆布
６ 短繊維[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a transmission belt such as a V-belt or a V-ribbed belt, and particularly relates to a technical field of which the durability is improved.
[0002]
[Prior art]
Conventionally, transmission belts such as V-belts and V-ribbed belts are well known. This belt includes an adhesive rubber layer in which a core wire made of a rope such as polyester fiber or aramid fiber is embedded, and a compression rubber layer integrally formed on the belt bottom surface side of the adhesive rubber layer. . Since the adhesive rubber layer is used for the purpose of improving the adhesion to the core wire, when the belt is vulcanized, the adhesive rubber layer must be fluidized by heating and bonded to the core wire at the interface. Is done. For this reason, soft rubber is mainly used in terms of compounding.
[0003]
On the other hand, the compression rubber layer is required to have a high elastic modulus for the purpose of preventing deformation of the belt and improving the transmission capability. Therefore, as a result, the difference in elastic modulus at the interface between the adhesive rubber layer, the compressed rubber layer and the core wire becomes large, stress concentration occurs at the interface, and cracks occur at the interface, resulting in the belt life. There is a problem that leads to.
[0004]
Therefore, in order to solve such problems, a rubber composition reinforced with a silane coupling material, hydrous silicic acid, or carbon black is conventionally used for the adhesive rubber layer as disclosed in, for example, Japanese Patent Publication No. 63-28788. As shown in Japanese Patent Application Laid-Open No. 57-204351, a core wire is provided at the interface between the adhesive rubber layer and the compression rubber layer, and the covering state of each rubber layer with respect to the core wire is set to a predetermined ratio. The one arranged so is proposed.
[0005]
[Problems to be solved by the invention]
By the way, in order to suppress the difference in elastic modulus at the interface between the adhesive rubber layer, the compressed rubber layer, and the core wire, it is conceivable to increase the elastic modulus of the adhesive rubber layer. However, just by reinforcing the adhesive rubber layer as in the former conventional example, the viscosity of the rubber increases and an expected high elastic modulus cannot be obtained.
[0006]
The present invention has been made in view of such points, and an object of the present invention is to improve the adhesive rubber layer in the transmission belt so that the elastic modulus of the adhesive rubber layer at the interface between the compressed rubber layer and the core wire is obtained. It is to extend the belt life by eliminating the difference.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, in the present invention, the adhesive rubber layer itself in the transmission belt is made of a highly elastic rubber composition having substantially the same elastic modulus as that of the compression rubber layer.
[0008]
That is, in the invention of claim 1, in a transmission belt comprising an adhesive rubber layer in which a core wire extending in the belt length direction is embedded, and a compression rubber layer provided on the belt bottom surface side of the adhesive rubber layer. The adhesive rubber layer is composed of a highly elastic rubber composition in which short fibers are mixed and dispersed and has an elastic modulus substantially equal to that of the compressed rubber layer.
[0009]
With the above configuration, the adhesive rubber layer becomes a highly elastic rubber layer having substantially the same elastic modulus as the compressed rubber layer, so there is no difference in elastic modulus at the interface between the compressed rubber layer and the core wire of the adhesive rubber layer, Stress concentration at the interface is less likely to occur, cracking at the interface can be suppressed, and the life of the belt can be extended.
[0010]
According to a second aspect of the present invention, in the power transmission belt of the first aspect, at least the adhesive rubber layer is formed of a rubber composition in which short fibers are uniformly dispersed in a latex state during the polymer production process.
[0011]
By carrying out like this, the rubber composition used as the highly elastic adhesive rubber layer which has an elastic modulus substantially equivalent to the said compression rubber layer is concretely easily realizable. At that time, since the short fibers in the adhesive rubber layer are uniformly dispersed in the latex state of the polymer, the short fibers are highly dispersed in the adhesive rubber layer, and the adhesiveness to the rubber becomes sufficient and stress concentration is applied. It can suppress that the interface of the fiber and rubber in the easy adhesive rubber layer becomes the nucleus of crack generation.
[0012]
According to a third aspect of the present invention, in the power transmission belt of the second aspect, the short fiber is a fiber selected from the group consisting of an aramid fiber, a cotton fiber and a silk fiber having a high elastic modulus. Since these fibers themselves have a high elastic modulus, the elastic modulus of the adhesive rubber layer can be increased while a relatively small amount of short fibers are mixed to ensure fluidity of the rubber in a latex state.
[0013]
In the invention of claim 4, in power transmission belt of the invention of claim 2 or 3, the short fibers are assumed to have been fibrillated. By doing so, the surface area of the short fiber is increased, so that the adhesiveness with the rubber can be further improved.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
(Embodiment 1)
FIG. 1 shows a V-belt B as a transmission belt according to Embodiment 1 of the present invention. This V-belt B has a well-known basic structure, and an adhesive rubber layer 2 in which cores 1 extending in the belt length direction are embedded in a spiral shape, and a belt bottom surface side (belt inner surface side) of the adhesive rubber layer 2 ), And the upper canvas 4 is integrally formed on the back side (belt outer surface side) of the adhesive rubber layer 2, and the bottom canvas 5 is integrally formed on the bottom side of the compressed rubber layer 3. It is joined.
[0015]
As a feature of the present invention, the adhesive rubber layer 2 and the compressed rubber layer 3 are a rubber composition in which the short fibers 6, 6,... It consists of Therefore, the adhesive rubber layer 2 is composed of a highly elastic rubber composition having substantially the same elastic modulus as the compressed rubber layer 3. The polymer is preferably CR or ACSM.
[0016]
The short fibers 6, 6,... Are oriented so as to extend in the width direction of the belt B, and the composition ratio thereof to the rubber composition is, for example, 1/3. It is set to such an extent that sometimes the fluidity is insufficient and the cores 1 and 1 do not become porous. Further, the short fiber 6 is as micro as possible in consideration of the fluidity of rubber, and in order to obtain a high elastic modulus in a small amount, a fiber having a high elastic modulus is used. . That is, the short fibers 6 are made of high elastic modulus fibers such as aramid fibers such as Kevlar and Technora, cotton fibers, and silk fibers.
[0017]
Further, the short fiber 6 is a highly fibrillated pulp . The length of the short fiber 6 is desirably 1 mm or less, and a high elastic modulus can be obtained by reducing the pulp diameter and increasing L / D (fiber length / fiber diameter).
[0018]
Therefore, in this embodiment, the rubber composition in which the adhesive rubber layer 2 and the compressed rubber layer 3 in the V-belt B are uniformly dispersed (mixed) with the short fibers 6, 6,. Therefore, as the adhesive rubber layer 2, a highly elastic rubber composition having substantially the same elastic modulus as that of the compressed rubber layer 3 can be specifically easily obtained. Thus, since the adhesive rubber layer 2 and the compressed rubber layer 3 are the same highly elastic rubber composition, the difference in elastic modulus at the interface between the adhesive rubber layer 2 and the compressed rubber layer 3 and the core wire 1 is small. Therefore, stress concentration at the interface is unlikely to occur, and crack generation at the interface can be suppressed to extend the life of the belt.
[0019]
At that time, since the short fibers 6, 6,... In the adhesive rubber layer 2 are uniformly dispersed in a polymer latex state, the short fibers 6, 6,. It is possible to prevent the interface between the fiber and the rubber in the adhesive rubber layer 2 that is easily subjected to stress concentration from becoming a nucleus of crack generation, which is further advantageous in extending the belt life.
[0020]
In addition, due to the proper setting of the composition ratio of the short fibers 6, 6,... To the rubber composition, the short fibers 6, 6,. It is possible to prevent the belt from becoming porous, and it is possible to prevent early breakage of the belt B during traveling.
[0021]
Further, since the short fiber 6 is a fiber having a high elastic modulus such as an aramid fiber, an adhesive rubber layer is obtained while ensuring the fluidity of the rubber in a latex state with a small amount of the short fibers 6, 6,. The elastic modulus of 2 can be increased.
[0022]
Moreover, since the short fiber 6 is a fibrillated pulp , its surface area is increased, and the adhesiveness between the short fiber 6 and rubber can be further improved.
[0023]
(Embodiment 2)
FIG. 2 shows a second embodiment (the same parts as those in FIG. 1 are denoted by the same reference numerals and detailed description thereof is omitted) and applied to a V-ribbed belt B ′. That is, the V-ribbed belt B ′ includes an adhesive rubber layer 2 in which a core wire 1 extending in the belt length direction is embedded, and a compression rubber layer 3 ′ integrally formed on the belt bottom surface side of the adhesive rubber layer 2. The upper canvas 4 is integrally joined to the back side of the adhesive rubber layer 2. Further, three rib portions 3a ′, 3a ′,... Extending in the belt length direction are formed on the bottom surface of the compressed rubber layer 3 ′. The adhesive rubber layer 2 and the compressed rubber layer 3 'are composed of a highly elastic rubber composition having substantially the same elastic modulus, and this rubber composition has the same configuration as that of the first embodiment.
[0024]
Therefore, also in this embodiment, the same function and effect as in the first embodiment can be obtained, and the life characteristics of the V-ribbed belt B ′ can be improved.
[0025]
In each of the above embodiments, both the adhesive rubber layer 2 and the compressed rubber layers 3 and 3 'are made of a rubber composition having a polymer in which short fibers 6, 6,... Are uniformly dispersed. Only the layer 2 can be composed of the same rubber composition.
[0026]
【Example】
Next, specific examples will be described. Three types of V belts according to Embodiment 1 (Invention Examples 1 to 3) and three types of V belts for comparison (Comparative Examples 1 to 3) were produced. The respective compositions are as shown in Table 1 below. In Table 1, “Kevlar pulp masterbatch” is a product name “6F723” manufactured by DuPont, the pulp diameter is 10 to 12 μm, and the average fiber length is 0.8 mm.
[0027]
[Table 1]

[0028]
Next, as shown in FIG. 3, each belt B produced above is wound between the driving and driven pulleys 11 and 12 each consisting of a V pulley having a pulley diameter of 85 mm, and an atmosphere at room temperature (20 to 30 ° C.). In the state where a dead weight of 100 kg is applied to the driven pulley 12 in a direction away from the driving pulley 11 and a predetermined transmission load is applied to the driven pulley 12, the driving pulley 11 is rotated at 4900 rpm, and a belt running test is performed. The separation life until cracking occurred at the interface between the adhesive rubber layer, the compressed rubber layer and the core wire of each belt B was measured. The results are shown in Table 2 below.
[0029]
[Table 2]

[0030]
As is apparent from Table 2, it can be seen that the belt according to the present invention has a significantly longer separation life than the comparative example. In Comparative Example 3, the viscosity was too high and the amount of carbon could not be increased any more.
[0031]
【The invention's effect】
As described above, according to the first aspect of the present invention, in the transmission belt, the adhesive rubber layer in which the core wire is embedded is a compressed rubber layer in which fibers are mixed and dispersed and provided on the belt bottom surface side of the adhesive rubber layer. Is made of a highly elastic rubber composition having substantially the same elastic modulus as that of the adhesive rubber layer, there is no difference in elastic modulus at the interface between the compression rubber layer and the core wire, and cracking due to stress concentration at the interface is eliminated. It is possible to reduce the life of the transmission belt.
[0032]
According to the invention of claim 2, the at least adhesive rubber layer is made of a rubber composition in which short fibers are dispersed in a latex state in a polymer production process, so that a high elasticity having substantially the same elastic modulus as that of the compressed rubber layer is obtained. A rubber composition suitable for forming an adhesive rubber layer can be specifically and easily realized.
[0033]
According to the invention of claim 3, the short fiber is made of a high elastic modulus fiber such as aramid fiber, cotton fiber, silk fiber, etc., so that the mixing amount of the short fiber is reduced and the fluidity in the latex state of the rubber is secured. However, the elastic modulus of the adhesive rubber layer can be increased.
[0034]
According to the invention of claim 4, the short fibers can be by having a larger surface area fibrillated, further improved the adhesion between the short fiber rubber.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a V-belt according to a first embodiment of the present invention.
FIG. 2 is a cross-sectional view of a V-ribbed belt according to a second embodiment.
FIG. 3 is a schematic view of a belt running test apparatus.
[Explanation of symbols]
B V belt B 'V ribbed belt 1 Core wire 2 Adhesive rubber layer 3, 3' Compression rubber layer 4, 5 Canvas 6 Short fiber

Claims (4)

In a transmission belt comprising an adhesive rubber layer in which a core wire extending in the belt length direction is embedded, and a compression rubber layer provided on the belt bottom surface side of the adhesive rubber layer,
A power transmission belt , wherein the adhesive rubber layer is composed of a highly elastic rubber composition in which short fibers are mixed and dispersed and has an elastic modulus substantially equal to that of the compressed rubber layer. The power transmission belt according to claim 1,
A power transmission belt, wherein at least the adhesive rubber layer is composed of a rubber composition in which short fibers are uniformly dispersed in a latex state in a polymer production process. The power transmission belt according to claim 2,
Short fibers, aramid fibers, high modulus, power transmission belt, characterized in that a fiber comprising selected from cotton fibers and Kinu繊Wei or Ranaru group. The power transmission belt according to claim 2 or 3,
Short fibers, power transmission belt which is characterized in that which has been fibrillated.

Images