Power transmission joined v-belt

Abstract

To provide a power transmission joined V-belt having high durability in which longitudinal splitting and back surface cracking are unlikely to occur.SOLUTION: A power transmission joined V-belt 10 includes: an adhesive rubber layer 2 in which a cord 1 is embedded; a tension rubber layer 3 provided on an upper side of the adhesive rubber layer 2; a back fabric layer 6 provided on an upper surface of the tension rubber layer 3; a compression rubber layer 5 provided on a lower side of the adhesive rubber layer 2; and groove portions 7 recessed so as to extend in a belt longitudinal direction in a bottom surface of the compression rubber layer 5. By the groove portions 7, multiple uncovered, V-shaped cross-section V-belt portions 8 are arranged side by side in a belt width direction, the groove portions 7 reaching the tension rubber layer 3, and a ratio (T / H) of a thickness (T) of portions in the compression rubber layer 5 and the back fabric layer 6 where the groove portions 7 are not formed to an overall thickness (H) of the belt is set to 0.12 or more and 0.25 or less.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a raw edge type coupled V-belt for power transmission, in which a plurality of V-belt portions, each having a V-shaped cross section and not covered with canvas or the like, are arranged in parallel in the belt width direction. [Background technology]

[0002] Conventionally, as disclosed in Patent Document 1, for example, a coupled V-belt for power transmission has been known, which includes an adhesive rubber layer in which cords are embedded, an upper rubber layer provided on the upper side of the adhesive rubber layer, a back fabric layer made of a stretchable fabric adhered to the upper surface of the upper rubber layer, and a bottom rubber layer provided below the adhesive rubber layer in which short fibers extending in the belt width direction are embedded, and in which a groove extending in the belt length direction is formed in the bottom surface of the belt, and the groove arranges multiple V-belt portions with V-shaped cross sections side by side in the belt width direction. In this coupled V-belt for power transmission, the bottom of the groove is located in the upper rubber layer.

[0003] Also, as disclosed in Patent Document 2, for example, a method for manufacturing a combined V-belt is known, which manufactures a combined V-belt having at least one V-groove with a V-shaped cross section. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-241513 [Patent Document 2] Japanese Patent Application Publication No. 2017-042877 Summary of the Invention [Problem to be solved by the invention]

[0005] In this type of power transmission belt, the bottom of the groove reaches the tension rubber layer side, so if the non-grooved joint portion is too thin, the tension rubber layer side will tear in the belt length direction, which is known as "vertical tearing."On the other hand, if the non-grooved joint portion is too thick, tensile load will be easily applied to the back fabric layer side, causing back cracks and peeling due to flex fatigue, etc.

[0006] The present invention has been made in view of the above points, and an object of the present invention is to provide a coupled V-belt for power transmission that is resistant to longitudinal tears and back cracks and has high durability. [Means for solving the problem]

[0007] In order to achieve the above object, the present invention specifies an optimum shape for a highly durable coupled V-belt for power transmission.

[0008] Specifically, in the first invention, an adhesive rubber layer in which a core wire is embedded; a tension rubber layer provided on the adhesive rubber layer; a back fabric layer provided on the upper surface of the tension rubber layer; a compression rubber layer provided below the adhesive rubber layer; a groove portion recessed in a bottom surface of the compression rubber layer so as to extend in the belt length direction, The grooves allow a plurality of uncovered V-shaped cross-section V-belt portions to be arranged side by side in the belt width direction, The groove reaches the tension rubber layer, The ratio (T / H) of the thickness (T) of the portion of the compression rubber layer and the backing fabric layer where the grooves are not formed to the thickness (H) of the entire belt is 0.12 or more and 0.25 or less.

[0009] If the T / H value is less than 0.12, the back fabric layer and tensile rubber layer are too thin and weak, making them prone to vertical tearing. On the other hand, if the T / H value is greater than 0.25, the back fabric layer and tensile rubber layer are too thick, making them prone to back cracking and peeling due to the application of tensile load to the upper surface. However, with the above configuration, the back fabric layer and tensile rubber layer are less prone to defects and have improved durability.

[0010] In the second invention, in the first invention, The value of T / H is 0.12 or more and 0.20 or less.

[0011] According to the above configuration, by setting the T / H value to 0.20 or less, the thickness of the tension rubber layer and the back fabric layer in the areas where no grooves are provided becomes optimal, further improving durability.

[0012] In the third invention, in the second invention, The value of T / H is 0.15 or more and 0.16 or less.

[0013] According to the above configuration, by limiting the value of T / H to 0.15 or more and 0.16 or less, the thickness of the portions of the compression rubber layer and the back fabric layer where no grooves are provided becomes more optimal, further improving durability.

[0014] In a fourth aspect of the present invention, in any one of the first to third aspects of the present invention, The ratio (T / h) of a thickness (T) of a portion of the compression rubber layer and the back fabric layer where the groove portion is not formed to a position (h) of the core wire in the thickness direction from the upper surface of the back fabric layer is 0.39 or more and 0.77 or less.

[0015] Here, if T / h, which indicates the location of the highly rigid cord, is less than 0.39, vertical tearing is likely to occur. On the other hand, if T / h, which indicates the location of the cord, is greater than 0.78, tensile load is likely to occur on the back side, making back cracks more likely to occur. However, with the above configuration, the cord is positioned in an appropriate position, making the back fabric layer and tension rubber layer less susceptible to defects and improving durability.

[0016] In the fifth invention, in the fourth invention, The value of T / h is 0.49 or more and 0.54 or less.

[0017] According to the above configuration, the core wire is positioned more optimally, and durability is further improved. [Effects of the Invention]

[0018] As described above, according to the present invention, a coupled V-belt for power transmission that is resistant to longitudinal tears and back cracks and has high durability can be obtained. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a cross-sectional view showing a coupled V-belt for power transmission according to an embodiment of the present invention. [Figure 2] FIG. 2 is a schematic diagram showing running test conditions. DETAILED DESCRIPTION OF THE INVENTION

[0020] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0021] FIG. 1 shows a coupled V-belt 10 for power transmission according to an embodiment of the present invention. This coupled V-belt 10 for power transmission has an adhesive rubber layer 2 in which a core wire 1 is embedded at a central position in the thickness direction thereof.

[0022] The core wires 1 are wound spirally in a state aligned in the width direction of the belt, and are made of, for example, a polyester cord or an aramid cord with a wire diameter of 0.6 to 1.5 mm.

[0023] The adhesive rubber layer 2 is for adhering the embedded core wires 1 to the tension rubber layer 3 and the compression rubber layer 5, and is made of, for example, CR, NBR, EPDM, polymer rubber, or the like.

[0024] The tension rubber layer 3 is provided on the upper side of the adhesive rubber layer 2 and is a layer based on, for example, CR, NBR, EPDM, polymer rubber, etc., in which a large number of short fibers (cotton fibers, vinylon fibers, nylon fibers, aramid fibers, or a mixture of these fibers) are embedded in the rubber base along the belt width direction.

[0025] The back fabric layer 6 is provided on the upper surface of the tension rubber layer 3 and is made of stretchable canvas woven in 1 ply or 2 ply (as in the illustrated example) of cotton, cotton nylon, cotton polyester, etc., and is made of wide-angle canvas with a thread angle of 120°.

[0026] The compressed rubber layer 5 is provided below the adhesive rubber layer 2 and is made of, for example, the same material as the tension rubber layer 3. A recessed groove 7 extending in the belt length direction is formed in the bottom surface of this compressed rubber layer 5. This results in multiple V-belt portions 8 with a V-shaped cross section that are not covered with canvas or the like and are arranged side by side in the belt width direction. The groove 7 reaches the tension rubber layer 3. The combined V-belt for power transmission 10 is a so-called raw edge type in which the pulley contact surfaces of the V-belt portions 8 are not covered with canvas or the like.

[0027] In this embodiment, as shown in FIG. 1, the ratio (T / H) of the thickness (T) of the portion of the compressed rubber layer 5 and the back fabric layer 6 where the grooves 7 are not formed to the thickness (H) of the entire belt is 0.12 or more and 0.25 or less (0.12≦T / H≦0.25).

[0028] Preferably, the value of T / H is 0.12 or more and 0.20 or less (0.12≦T / H≦0.20).

[0029] More preferably, the value of T / H is 0.15 or more and 0.16 or less (0.15≦T / H≦0.16).

[0030] The ratio (T / h) of the thickness (T) of the portion of the compression rubber layer 5 and the back fabric layer 6 where the groove portion 7 is not formed to the position (h) in the thickness direction from the top surface of the back fabric layer 6 of the core wire 1 is 0.39 or more and 0.77 or less (0.39≦T / h≦0.77).

[0031] Preferably, the value of T / h is equal to or greater than 0.49 and equal to or less than 0.54 (0.49≦T / h≦0.54).

[0032] -Example- Next, a running test for confirming durability conducted on the example and comparative examples of the power transmission combined V-belt 10 according to the present embodiment will be described with reference to FIG.

[0033] [Table 1]

[0034] First, combined V-belts for power transmission are prepared for Comparative Examples 1 to 3 and Examples 1 to 9 as shown in Table 1. Here, these combined V-belts for power transmission are of type A, in which the ridge pitch P of the V-belt portion 8 is 10.3 mm, and type B, in which it is 17.5 mm.

[0035] The pulley sizes used for Type A and Type B are different, so the test conditions are different, but the test results show similar trends, so they have been compiled into one table.

[0036] The running test device was equipped with a drive pulley DR, a driven pulley DN, and an idler pulley ID, and the transmission combined V-belt was wound around these pulleys in an external loop state. The shaft of the idler pulley ID was pressed against the outside of the transmission combined V-belt with a load DW to apply belt tension, and a load was applied to the driven pulley DN in a high-temperature atmosphere at 85°C to drive and rotate the drive pulley DR, causing the transmission combined V-belt to run at high speed on each pulley.

[0037] For Type A, two V-belt sections 8 with a ridge pitch P of 10.3 mm were arranged in the belt width direction, the drive pulley DR had a pulley diameter of 80 mm, a rotation speed of 4900 rpm, the driven pulley DN had a pulley diameter of 80 mm and a load of 2.5 kW was applied, the idler pulley ID had a pulley diameter of 56 mm, and the test was conducted under the following conditions:

[0038] For Type B, the test was conducted with two V-belt sections 8 with a ridge pitch P of 17.5 mm arranged in the belt width direction, the drive pulley DR having a pulley diameter of 150 mm and a rotation speed of 4900 rpm, the driven pulley DN having a pulley diameter of 150 mm and a load of 8.8 kW applied, the idler pulley ID having a pulley diameter of 112 mm, and a load DW of 1150 N applied.

[0039] In Table 1, Comparative Examples 1 and 2, Examples 1 to 9, and Comparative Example 3 are arranged so that the magnitude of T / H increases toward the right.

[0040] In Comparative Examples 1 and 2, in which the T / H value was less than 0.12, the back fabric layer 6 and the tension rubber layer 3 were too thin and weak, and vertical tearing occurred at a relatively early stage.

[0041] On the other hand, in Examples 1 to 9, where T / H is in the range of 0.12≦T / H≦0.25, no defects occurred in the back fabric layer 6 or the tension rubber layer 3, and after the required time had elapsed, cracks occurred in the compression rubber layer 5, which is the normal failure mode, and it was therefore found that these have the required durability.

[0042] Furthermore, it is clear that in Examples 1 to 7, where T / H is in the range of 0.12≦T / H≦0.20, the durability is particularly high with a durability of 153 hours to 210 hours.

[0043] Furthermore, in Examples 1 to 5 where T / H was in the range of 0.15≦T / H≦0.16, the durability was extremely high at 186 hours to 210 hours, and it was found that the durability was even higher.

[0044] In Comparative Example 3, where the T / H value was in the range greater than 0.25, cracks and peeling occurred on the back surface after about 74 hours. This is thought to be because the back fabric layer 6 and tension rubber layer 3 were too thick, causing excessive tensile load to be applied to the upper surface.

[0045] Furthermore, in Examples 1 to 7, in which T / h was in the range of 0.39≦T / h≦0.77, the durability was 153 to 210 hours, demonstrating high durability. In particular, in Examples 2 to 5, in which T / h was in the range of 0.49≦T / h≦0.54, the durability was extremely high, from 186 to 210 hours, demonstrating even higher durability.

[0046] On the other hand, in Comparative Examples 1 and 2, where the position of the cord with high rigidity is smaller than 0.39, it was found that longitudinal cracking was likely to occur.

[0047] Furthermore, when the core wire position is higher than 0.78, a tensile load is likely to occur on the back surface side, and it is understood that durability is likely to decrease compared to Examples 1 to 7.

[0048] Therefore, according to the combined V-belt 10 for power transmission according to this embodiment, it is possible to obtain a combined V-belt 10 for power transmission which is resistant to longitudinal tears and back cracks and has high durability.

[0049] It should be noted that the above-described embodiments are essentially preferred examples and are not intended to limit the scope of the present invention, its applications, or uses. [Explanation of symbols]

[0050] 1 core wire 2 Adhesive rubber layer 3. Tension rubber layer 5 Compressed rubber layer 6 back fabric layer 7 Groove 8 V-belt section 10. Power transmission V-belt

Claims

1. an adhesive rubber layer in which a core wire is embedded; a tension rubber layer provided on the adhesive rubber layer; a back fabric layer provided on the upper surface of the tension rubber layer; a compression rubber layer provided below the adhesive rubber layer; a groove portion recessed in a bottom surface of the compression rubber layer so as to extend in the belt length direction, The grooves allow a plurality of uncovered V-shaped cross-section V-belt portions to be arranged side by side in the belt width direction, The groove reaches the tension rubber layer, The ratio (T / H) of the thickness (T) of the portion of the compression rubber layer and the backing fabric layer where the grooves are not formed to the thickness (H) of the entire belt is 0.12 or more and 0.25 or less. A coupled V-belt for power transmission.

2. The value of T / H is 0.12 or more and 0.20 or less.

2. The power transmission V-belt according to claim 1.

3. The value of T / H is 0.15 or more and 0.16 or less.

3. The coupled V-belt for power transmission according to claim 2.

4. a ratio (T / h) of a thickness (T) of a portion of the compression rubber layer and the back fabric layer where no groove portion is formed to a position (h) of the cord in a thickness direction from the upper surface of the back fabric layer is 0.39 or more and 0.77 or less; 4. The power transmission V-belt according to claim 1, wherein the V-belt is a tubular member.

5. The value of T / h is 0.49 or more and 0.54 or less.

5. The coupled V-belt for power transmission according to claim 4.

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