Toothed belt and transmission system

Abstract

A toothed belt has a back portion in which a core wire is embedded; and a belt tooth provided on the inner peripheral side of the back portion and meshing with a pulley groove of a toothed pulley, in which the tooth crest compression ratio Y (%) of the belt tooth calculated by formula (1) is-2 < = Y < = 10, and the void ratio X (%) of the belt tooth in the tooth width direction calculated by formula (2) is-30 < = X < = 0. Y (%) = ((belt tooth height Hb-pulley tooth groove bottom depth Hp) / belt tooth height Hb) * 100 (1) X (%) = ((pulley tooth width [gamma]-pulley tooth width [beta]) / pulley tooth width [gamma]) * 100 (2)

Description

Technical Field

[0001] This invention relates to toothed belts and transmission systems.

[0002] This application claims priority based on Japanese Patent Application No. 2023-033896, filed on March 6, 2023, and invokes all the contents set forth in that Japanese patent application. Background Technology

[0003] As a system for transmitting power, transmission systems with toothed belts and toothed pulleys are known. Toothed belt transmission systems can achieve stable synchronous transmission with low tension. Therefore, they are suitable for use in general industrial machinery such as processing machinery and textile machinery, or in electric power steering systems.

[0004] On the other hand, the problem with the aforementioned transmission system is that the sound generated during driving (traveling sound) becomes noise.

[0005] To date, several methods have been proposed to reduce noise during the meshing of toothed belts and toothed pulleys.

[0006] For example, in Patent Document 1, a toothed belt capable of reducing noise is proposed as follows: the toothed belt has a back, a plurality of oblique teeth arranged in the belt length direction, and a core wire made of fibers that is spirally embedded in the back along the belt length direction. The oblique teeth have toothed cloths provided on the inner circumference side. The angle between the direction of the oblique teeth extending in the direction of the teeth and the belt width direction is more than 8 degrees and less than 16 degrees. The fibers constituting the core wire are made of single-twisted yarn. The twisting direction of the yarn is inclined in the opposite direction to the direction of the oblique teeth extending in the direction of the teeth, based on the belt width direction. The winding direction of the core wire is inclined in the same direction as the direction of the oblique teeth extending in the direction of the teeth, based on the belt width direction.

[0007] Prior art literature

[0008] Patent Literature

[0009] Patent Document 1: WO2014 / 091672 Summary of the Invention

[0010] The problem that the invention aims to solve

[0011] In transmission systems consisting of toothed belts and toothed pulleys, the requirement to reduce travel noise (suppress noise) remains. Noise suppression is particularly important in applications requiring quiet operation.

[0012] Methods for solving problems

[0013] The present invention was made in view of the actual situation, and its purpose is to provide a transmission system that suppresses noise.

[0014] (1) The toothed belt of the present invention has a back surface in which a core wire is embedded; and a toothed belt with teeth disposed on the inner circumferential side of the back surface, which meshes with the pulley groove of the toothed pulley.

[0015] The tooth tip compression ratio Y (%) calculated from equation (1) is -2≤Y≤10.

[0016] The void ratio X (%) in the tooth width direction of the toothed structure calculated by equation (2) is -30≤X≤0.

[0017] Y(%)=((belt tooth height Hb-pulley tooth groove depth Hp) / belt tooth height Hb)×100···(1)

[0018] X(%)=((pulley tooth width γ-pulley tooth width β) / pulley tooth width γ)×100··· (2)

[0019] Because the tooth tip compression ratio Y and the tooth width porosity X of this toothed belt are both within specified ranges, the traveling noise is reduced. This toothed belt suppresses noise.

[0020] (2) The toothed belt in (1) above is preferably,

[0021] The tooth tip compression ratio Y (%) is 0 ≤ Y ≤ 8, and the void ratio X (%) is -20 ≤ X ≤ -10.

[0022] In this case, noise can be further reduced.

[0023] (3) In the toothed strip of (1) or (2) above, the core wire is preferably a carbon core wire or a steel core wire.

[0024] In this configuration, the toothed belt exhibits excellent tension maintenance. Furthermore, the belt length is less prone to variation. Therefore, it is suitable for high-load transmission applications.

[0025] (4) Among the toothed strips in any of (1) to (3) above, the preferred one is,

[0026] The teeth mentioned above are helical teeth.

[0027] The angle between the tooth direction of the aforementioned helical teeth and the bandwidth direction is more than 3 degrees and less than 16 degrees.

[0028] In this way, the knocking noise when the belt teeth mesh with the pulley grooves can be reduced. Therefore, noise is further suppressed.

[0029] (5) In the toothed band of (4) above,

[0030] The ratio B of the thickness Sb of the back surface to the tooth height Hb of the oblique tooth is preferably 1.75 or more and 2.40 or less.

[0031] In this configuration, the toothed belt further suppresses noise. Furthermore, due to the ensured resistance to bending fatigue, cracks are less likely to form on the back side of the toothed belt.

[0032] (6) The transmission system of the present invention is a transmission system having a toothed belt and a toothed pulley that meshes with the toothed belt.

[0033] The toothed belt described above is any one of (1) to (5).

[0034] Because the transmission system has a toothed belt as described in any one of (1) to (5), the travel noise is reduced. The transmission system suppresses noise.

[0035] The effects of the invention

[0036] According to the present invention, a toothed belt capable of suppressing noise can be provided. Additionally, a transmission system incorporating the toothed belt that suppresses noise can be provided. Attached Figure Description

[0037] [ Figure 1 [This is a schematic side view of the transmission system.]

[0038] [ Figure 2 [This is a perspective view schematically showing the toothed band.]

[0039] [ Figure 3 ]yes Figure 2 AA-line cross-section view.

[0040] [ Figure 4 ]yes Figure 2 BB line end face view.

[0041] [ Figure 5 [ ] is a diagram illustrating the shape of the pulley groove.

[0042] [ Figure 6 [ ] is a diagram illustrating the manufacturing method of toothed belts.

[0043] [ Figure 7 [ ] is a diagram illustrating the manufacturing method of toothed belts.

[0044] [ Figure 8 [ ] is a diagram illustrating the manufacturing method of toothed belts.

[0045] [ Figure 9 [ ] is a diagram showing the dimensions of the toothed band.

[0046] [ Figure 10 [ ] is a diagram showing the dimensions of the pulley groove.

[0047] [ Figure 11[Illustration] is a diagram showing the pulley layout of the transmission system prepared in the embodiments and comparative examples.

[0048] [ Figure 12 [ ] is a graph showing the evaluation results of the embodiments and comparative examples. Detailed Implementation

[0049] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The present invention is not limited to these embodiments.

[0050] (Transmission system)

[0051] Figure 1 This is a schematic side view of the transmission system 1 according to an embodiment of the present invention.

[0052] Transmission system 1 is suitable for general industrial machinery such as processing machinery, printing machinery, fiber machinery, injection molding machines, and electric power steering devices.

[0053] like Figure 1 As shown, the transmission system 1 includes a drive pulley 22, a driven pulley 24, and a toothed belt 10.

[0054] The drive pulley 22 and the driven pulley 24 each have multiple pulley grooves 21. The toothed belt 10 has multiple belt teeth 12 on its inner circumference that mesh with the pulley grooves 21 (see reference). Figure 2 The toothed belt 10 has a core wire 13 embedded in it. The toothed belt 10 is hung on the drive pulley 22 and the driven pulley 24.

[0055] Both the drive pulley 22 and the driven pulley 24 have pulley grooves 21 at equal intervals along their outer circumferences, which mesh with the teeth 12 of the toothed belt 10. The pulley grooves 21 of the drive pulley 22 and the driven pulley 24 have the same shape. Hereinafter, the drive pulley 22 and the driven pulley 24 will be referred to together as the toothed pulley 20.

[0056] The transmission system 1 transmits power from the drive source to the driven side. In the transmission system 1, the belt travel speed is, for example, between 0 rpm and 6000 rpm. In the transmission system 1, the transmission capacity is, for example, between 0.1 kW and 10 kW.

[0057] (toothed band)

[0058] Figure 2 This is a perspective view showing a portion of the toothed belt 10 according to an embodiment of the present invention. The toothed belt 10 constitutes a transmission system 1.

[0059] Figure 3 yes Figure 2 AA-line cross-section view.

[0060] Figure 4 yes Figure 2 BB line end face view.

[0061] Figure 2 Only a portion of the toothed belt 10 is shown, but the toothed belt 10 is an endless meshing drive belt. Furthermore, the toothed belt 10 is a single-sided toothed belt.

[0062] The length of the toothed belt 10 (the length of the belt spacing line BL) is, for example, more than 100 mm and less than 400 mm.

[0063] The bandwidth Wb of the toothed belt 10 is, for example, 4mm or more and 30mm or less.

[0064] The thickness Tb of the toothed belt 10 is, for example, 1.1 mm or more and 3.0 mm or less. The thickness Tb of the toothed belt 10 is the thickness of the thickest part of the toothed belt 10.

[0065] The dimensions of the toothed belt involved in the embodiments of the present invention are not limited to this range.

[0066] The toothed belt 10 has multiple teeth 12 on its inner circumferential surface.

[0067] The spacing Pb of the toothed 12 is, for example, 0.50 mm or more and 3.0 mm or less.

[0068] For example, the tooth profile of tooth 12 is a circular arc tooth profile.

[0069] (toothed pulley)

[0070] The toothed pulley 20 is made of stainless steel, for example. The toothed pulley 20 has pulley grooves 21 along its outer periphery at a predetermined interval that engage with the teeth 12 of the toothed belt 10.

[0071] The outer diameter of the toothed pulley 20 is, for example, 8 mm or more and 144 mm or less.

[0072] The toothed pulley 20 has, for example, 10 to 150 teeth.

[0073] The tooth profile of the pulley groove 21 is, for example, a circular arc tooth profile.

[0074] The toothed pulley 20 may, for example, have a flange.

[0075] (The relationship between toothed belts and toothed pulleys)

[0076] The teeth 12 of the toothed belt 10 are configured to smoothly mesh with the pulley groove 21.

[0077] The tooth tip compression ratio Y (%) of the tooth 12 of the toothed belt 10 and the clearance ratio X (%) in the tooth width direction of the tooth 12 are within a specific range.

[0078] The tooth tip compression ratio Y(%) of the toothed belt 12 is an index representing the compression state of the tooth tip of the toothed belt 12 when it meshes with the pulley groove 21. The tooth tip compression ratio Y(%) of the toothed belt 12 is calculated by the following formula (1).

[0079] Y(%)=((belt tooth height Hb-pulley tooth groove depth Hp) / belt tooth height Hb)×100…(1)

[0080] In equation (1), the tooth height Hb is the distance between the apex of the tooth and the bottom line of the tooth in a cross-section along the length of the toothed band 10 (refer to...). Figure 4 Hb in (the substance).

[0081] For example, the tooth height Hb of toothed band 10 is between 0.50 mm and 2.0 mm.

[0082] In equation (1), the tooth groove bottom depth Hp of the pulley is defined as the radial distance between the tooth tip circle Cp and the tooth groove bottom circle Cq in the circumferential section along the toothed pulley 20 (refer to...). Figure 5 ).

[0083] The tooth groove depth Hp of the toothed pulley 20 is, for example, 0.40 mm or more and 2.20 mm or less.

[0084] The backlash X (%) in the tooth width direction of the belt tooth 12 is an index representing the amount of backlash when the belt tooth 12 meshes with the pulley groove 21. The backlash X (%) in the tooth width direction of the belt tooth 12 is calculated by the following formula (2).

[0085] X(%)=((pulley tooth width γ-pulley tooth width β) / pulley tooth width γ)×100··· (2)

[0086] In equation (2), the belt tooth width β is the distance between P1 and P2 when the intersection of the imaginary straight line VL1, which is the part of the belt tooth height Hb that is orthogonal to the direction of the belt tooth height Hb, and the pressure surface of the belt tooth 12 is set as P1 and P2 in the cross section along the length direction of the toothed belt 10.

[0087] The tooth width β is, for example, 0.50 mm or more and 3.00 mm or less.

[0088] In equation (2), the pulley tooth width γ is the distance between P3 and P4 when the intersection of the imaginary arc VL2, which is part of the concentric circle of the tooth tip circle Cp and the portion passing through half the depth of the tooth groove bottom Hp of the pulley, with the tooth surface of the toothed pulley 20 is set as P3 and P4.

[0089] The pulley tooth width γ is, for example, 0.50mm or more and 3.00mm or less.

[0090] The tooth tip compression ratio Y (%) of the tooth 12 of the toothed belt 10 is -2≤Y≤10, and the clearance ratio X (%) in the tooth width direction of the tooth 12 is -30≤X≤0.

[0091] In this embodiment, the compression state of the tooth tip and the backlash of the tooth 12 when it meshes with the pulley groove 21 are set within a specified range. Under these conditions, the toothed belt 10 can mesh smoothly with the toothed pulley 20. Therefore, the toothed belt 10 can reduce noise.

[0092] Let me elaborate on this a little more.

[0093] In this embodiment, when the gear 12 engages with the pulley groove 21, the tooth tips and pressure surfaces on both sides of the gear 12 contact the pulley groove 21. Therefore, the vibration source is dispersed, and engagement becomes smooth. As a result, noise can be further reduced.

[0094] It should be noted that the excitation source refers to the location where meshing impact sound or string vibration sound, which is a component of noise, is generated. When the toothed belt 12 meshes with the pulley groove 21, the contact area between the two is equivalent to the excitation source.

[0095] When the tooth tip compression ratio Y (%) is less than -2, the toothed belt 10, when meshing with the toothed pulley, becomes a state where the tooth tip does not contact the pulley groove 21. In this case, the excitation source is not dispersed but concentrated at the tooth root 15 of the toothed belt 10. Therefore, the transmission system 1 cannot adequately suppress noise.

[0096] Furthermore, when the tooth tip compression ratio Y (%) exceeds 10, the toothed belt 10 becomes a state where the tooth bottom 15 is lifted when meshing with the toothed pulley. In this case, the excitation source is not dispersed but concentrated at the tooth tip of the toothed belt 10. Therefore, the transmission system 1 cannot adequately suppress noise.

[0097] When the clearance ratio X (%) is less than -30, the interference of the pressure surface increases when the toothed belt 10 meshes with the toothed pulley 20. Therefore, the noise of the transmission system 1 cannot be sufficiently suppressed.

[0098] Furthermore, when the clearance ratio X (%) is greater than 0, the toothed belt 10, when meshing with the toothed pulley, becomes a state where only one side of the pressure surface of the teeth 12 contacts the pulley groove 21. In this case, the excitation source is concentrated on the pressure surface of only one side of the teeth 12. Therefore, the noise of the transmission system 1 cannot be sufficiently suppressed.

[0099] Preferably, the toothed belt 10 has a tooth tip compression ratio Y (%) of 0 ≤ Y ≤ 8 and a void ratio X (%) of -20 ≤ X ≤ -10.

[0100] In this configuration, in addition to dispersing the excitation source, the interference state between the pressure surface of the toothed belt 12 and the tooth surface of the toothed pulley becomes appropriate. In other words, it achieves a state where both pressure surfaces of the toothed belt 12 are in contact with the tooth surface of the toothed pulley simultaneously, and the two pressure surfaces of the toothed belt 12 are not excessively compressed. As a result, the noise of the transmission system 1 is further reduced.

[0101] In this embodiment, the tooth tip compression ratio Y (%) and void ratio X (%) of the toothed belt 10 preferably satisfy the relationship of equation (3).

[0102] Y≥-0.45X - 4· · · (3)

[0103] In this case, the toothed belt 10 is particularly less prone to generating noise.

[0104] The teeth 12 of the toothed belt 10 are oblique teeth.

[0105] The angle of the tooth direction of the belt tooth 12, which is a helical tooth, is preferably 3 degrees or more and 16 degrees or less. In this case, when the toothed belt 10 meshes with the toothed pulley 20, the belt tooth 12 gradually meshes with the pulley groove 21 along the tooth direction from one side to the other, thus reducing the meshing impact noise. Therefore, the noise of the transmission system 1 is suppressed.

[0106] On the other hand, when the angle of the aforementioned tooth direction is less than 3 degrees, the impact noise during meshing will not become too small. In addition, when the angle of the aforementioned tooth direction exceeds 16 degrees, the toothed band is prone to misalignment during travel, which can lead to increased noise or deterioration of durability.

[0107] The toothed pulley 20 that meshes with the toothed belt 10 also has helical teeth.

[0108] In the toothed band 10, the thickness Sb of the back is relative to the tooth height Hb of the helical tooth (refer to...). Figure 4 The ratio B(Sb / Hb) is preferably 1.75 or higher and 2.40 or lower.

[0109] When the back thickness Sb of the toothed belt 10 increases, noise is more easily suppressed. This is because when the back thickness Sb increases, the vibration of the toothed belt, which is one of the causes of noise, can be attenuated.

[0110] On the other hand, when the thickness Sb of the back is too thick, the rigidity of the toothed belt 10 becomes too great, resulting in poor meshing with the pulley groove 21 when the toothed belt 10 is wound onto the toothed pulley 20. Furthermore, the bending fatigue resistance of the toothed belt decreases, making it prone to cracking on the back side and other locations. Cracks are particularly prone to forming at low temperatures.

[0111] For these reasons, in the toothed belt 10, the ratio B (Sb / Hb) is preferably within the range described above.

[0112] (The composition of the toothed band)

[0113] like Figure 2 As shown, the toothed belt 10 includes a belt body 11, a core wire 13, and a reinforcing cloth 14.

[0114] The belt body 11 includes: a base 11a with a rectangular cross-section that is strip-shaped and perpendicular to the belt length direction, and a plurality of teeth 11b disposed on the inner circumferential side of the base 11a. These plurality of teeth 11b are integral with the base 11a. The plurality of teeth 11b are equally spaced along the belt length direction at predetermined intervals.

[0115] In the toothed belt 10, the reinforcing fabric 14 is provided to cover the inner circumferential surface of the teeth 11b. In the toothed belt 10, the belt teeth 12 are composed of the teeth 11b and the reinforcing fabric 14.

[0116] The main body 11 is, for example, composed of a rubber composition formed by crosslinking an uncrosslinked rubber composition containing rubber components and rubber compounding agents through heating and pressurization.

[0117] Examples of the aforementioned rubber components include, for example, hydrogenated nitrile butadiene rubber (HNBR), chloroprene rubber (CR), ethylene-α-olefin elastomers such as ethylene propylene diene monomer (EPDM), chlorosulfonated polyethylene rubber, styrene-butadiene rubber, epichlorohydrin rubber, etc.

[0118] HNBR and EPDM are preferred.

[0119] As the aforementioned rubber compounding agents, conventionally known rubber compounding agents can be used. Examples of rubber compounding agents include vulcanization accelerators, anti-aging agents, reinforcing materials, plasticizers, co-crosslinking agents, and crosslinking agents.

[0120] Examples of vulcanization accelerators include metal oxides, metal carbonates, fatty acids and their derivatives. Examples of metal oxides include zinc oxide (zinc white) and magnesium oxide.

[0121] These vulcanization accelerators can be used in combination with one or more.

[0122] The content of the above-mentioned vulcanization accelerator is, for example, more than 3 parts by mass and less than 15 parts by mass relative to 100 parts by mass of rubber component.

[0123] Examples of anti-aging agents mentioned above include benzimidazole-based anti-aging agents, aromatic secondary amine-based anti-aging agents, and amine-ketone-based anti-aging agents. One or more of these anti-aging agents can be used together.

[0124] The content of the aforementioned anti-aging agent is, for example, 1.5 parts by mass or more and 3.5 parts by mass relative to 100 parts by mass of rubber component.

[0125] Examples of reinforcing materials mentioned above include carbon black and silicon dioxide. These reinforcing materials can also be used in combination with carbon black and silicon dioxide.

[0126] Examples of carbon blacks mentioned above include channel black, furnace black, pyrolytic carbon black, and acetylene black.

[0127] Examples of furnace blacks mentioned above include SAF, ISAF, N-339, HAF, N-351, MAF, FEF, SRF, GPF, ECF, and N-234.

[0128] Examples of pyrolytic carbon blacks include FT and MT.

[0129] Carbon black can be used in combination with one type or two or more types.

[0130] When carbon black is used, its content is, for example, more than 10 parts by mass and less than 30 parts by mass relative to 100 parts by mass of rubber component.

[0131] When silica is used, its content is, for example, more than 10 parts by mass and less than 30 parts by mass relative to 100 parts by mass of rubber component.

[0132] Examples of such plasticizers include dialkyl sebacate, dialkyl phthalate, and dialkyl adipate.

[0133] Examples of dialkyl sebacate as described above include polyether esters and dioctyl sebacate (DOS).

[0134] Examples of dialkyl phthalates mentioned above include dibutyl phthalate (DBP) and dioctyl phthalate (DOP).

[0135] Examples of dialkyl adipate esters include dioctyl adipate (DOA).

[0136] These plasticizers can be used in combination, either one or two or more.

[0137] The content of the aforementioned plasticizer is, for example, 5 to 15 parts by mass relative to 100 parts by mass of rubber component.

[0138] Examples of co-crosslinking agents mentioned above include trimethylolpropane trimethacrylate, m-phenylene dimaleimide, zinc dimethacrylate, and triallyl isocyanurate. Only one of these co-crosslinking agents may be used, or two or more may be used in combination.

[0139] The content of the aforementioned co-crosslinking agent is, for example, 3 to 8 parts by mass relative to 100 parts by mass of rubber component.

[0140] Examples of crosslinking agents mentioned above include sulfur and organic peroxides. Sulfur and organic peroxides can be used together. Of course, either one can also be used alone.

[0141] As the aforementioned crosslinking agent, when sulfur and organic peroxide are used together, the total amount of the aforementioned crosslinking agent is preferably, for example, 0.1 to 0.7 parts by mass and 1 to 5 parts by mass of sulfur relative to 100 parts by mass of rubber component.

[0142] Examples of core wires 13 include glass core wires, aramid core wires, carbon core wires, and steel core wires. These core wires are preferably made of twisted wires.

[0143] As the core wire 13, carbon core wire and steel core wire are preferred. Carbon or steel are materials with high elastic modulus. Therefore, toothed belts with carbon or steel core wires are less prone to length change and have small tooth pitch changes when a load is applied. Thus, toothed belts with carbon or steel core wires can easily maintain good meshing with toothed pulleys.

[0144] Regarding the outer diameter of the core wire 13, it is preferable that the outer diameter φT in the thickness direction and the outer diameter φW in the bandwidth direction are both 0.15 mm and 0.80 mm. More preferably, the outer diameters φT and φW are both 0.25 mm and 0.50 mm.

[0145] The outer diameter φT in the thickness direction and the outer diameter φW in the bandwidth direction can be the same or different.

[0146] The core wires 13 are arranged in a spiral configuration with spacing in the bandwidth direction. The core wires 13 are composed of both S-twist and Z-twist wires, which can also be arranged in a double spiral configuration.

[0147] The core wires 13 are configured to be spaced apart and extended in parallel in the bandwidth direction.

[0148] At this point, the number of core wires 13 per 10mm bandwidth is preferably 10 or more per 10mm and 26 or less per 10mm. This arrangement of core wires 13 in the toothed belt 10 ensures excellent durability and tension maintenance during high-load transmission. From the same viewpoint, a more preferred number of core wires 13 is 14 or more per 10mm and 24 or less per 10mm.

[0149] In addition, the gap between adjacent core wires 13 is, for example, 0.1 mm or more and 0.7 mm or less.

[0150] Alternatively, bonding treatment can be applied to the core wire 13 to improve its adhesion to the belt body.

[0151] Examples of the aforementioned bonding treatments include: RFL treatment, which involves immersing the material in an RFL aqueous solution and then heating it; and rubber paste treatment, which involves immersing the material in a rubber paste and then drying it. Only one of these bonding treatments may be performed, or both may be performed.

[0152] Alternatively, a substrate treatment can be performed on the core wire 13 before the aforementioned bonding treatment. Examples of such substrate treatments include immersion in an epoxy solution or isocyanate solution followed by heating.

[0153] In the toothed belt manufacturing method described later, these bonding and substrate treatments are performed before the core wire is wound onto the mold.

[0154] The reinforcing fabric 14 is composed of, for example, woven fabric, braided fabric, nonwoven fabric, etc.

[0155] Fibers constituting the reinforcing fabric 14 may include, for example, polyamide fibers (nylon fibers), polyester fibers, aramid fibers, poly(p-phenylenebenzodioxazole) (PBO) fibers, cotton, etc.

[0156] As the reinforcing fabric 14, a fabric made of polyamide fibers is preferred.

[0157] The reinforcing fabric 14 preferably has elasticity. For example, a fabric using weft yarns that have undergone a wool-like finishing process has elasticity. In this case, the reinforcing fabric 14 is preferably arranged in a way that facilitates elasticity and stretching, aligning with the length direction of the belt.

[0158] The thickness of the reinforcing fabric 14 is, for example, 0.05 mm or more and 0.8 mm or less.

[0159] Alternatively, an adhesive treatment can be applied to the reinforcing fabric 14 to improve its adhesion to the belt body 11.

[0160] Examples of the aforementioned bonding treatments include: RFL treatment involving immersion in an RFL aqueous solution followed by heating; immersion treatment involving immersion in a low-viscosity rubber paste followed by drying; and coating treatment involving applying a high-viscosity rubber paste to the surface of the main body side of the belt and then drying it. One or more of these methods may be performed.

[0161] Alternatively, the reinforcing fabric 14 can be subjected to a substrate treatment involving immersion in an epoxy solution or isocyanate solution followed by heating before bonding.

[0162] In the manufacturing method of the toothed belt described later, these bonding and substrate treatments are performed before attaching the 14 rolls of reinforcing fabric to the mold.

[0163] (Manufacturing method of toothed belt)

[0164] The manufacturing method of the toothed belt 10 will be explained according to the process sequence.

[0165] Figures 6 to 8 This is a diagram illustrating the manufacturing method of the toothed belt 10. Figures 6 to 8 The image shows only a portion of the mold 31 for forming the belt and the belt (including the belt material).

[0166] In the manufacture of the toothed belt 10, a belt forming mold 30 is used.

[0167] The mold 30 is cylindrical. A recess 31 extending axially and a protrusion 32 extending axially are provided on the outer periphery of the mold 30. The recess 31 has a cross-sectional shape corresponding to the toothed section 12 and extends axially (towards...). Figure 6 The groove extends in the direction perpendicular to the paper surface. The recesses 31 are spaced apart in the circumferential direction. The protrusions 32 are provided between adjacent recesses 31.

[0168] (1) Prepare materials.

[0169] The rubber components are kneaded and further mixed with rubber compounding agents to obtain an uncrosslinked rubber composition. The obtained uncrosslinked rubber composition is shaped to produce an uncrosslinked rubber composition sheet 111. At this time, the shaping method of the uncrosslinked rubber composition sheet 111 can be, for example, calendering.

[0170] Prepare the core wire 12 and the reinforcing cloth 14, and perform bonding treatment as needed.

[0171] In addition, the reinforcing fabric 14 is shaped into a tubular form.

[0172] (2) Layer materials sequentially. For example... Figure 6 As shown, firstly, a reinforcing fabric 14 shaped into a cylindrical form is covered on the outer peripheral surface of the mold 30. Next, the core wire 13 is spirally wound onto the reinforcing fabric 14.

[0173] Furthermore, an uncrosslinked rubber composition sheet 111 is wound onto it. Multiple sheets are wound on top. Figure 6 Two uncrosslinked rubber composite sheets 111 are stacked together. Thus, an uncrosslinked blank 135, formed by laminating the reinforcing fabric 14, the core wire 13, and the uncrosslinked rubber composite sheets 111, is formed on the mold 30. Preferably, the uncrosslinked rubber composite sheets 111 are stacked in a manner where the texture direction corresponds to the strip length direction.

[0174] (3) Figure 7As shown, a rubber sleeve 34 is placed over the uncrosslinked blank 135 on the mold 31, and the blank is then placed and sealed inside a vulcanizing tank. Next, high-temperature and high-pressure steam is filled into the vulcanizing tank. This state is maintained for a specified time. Thus, the uncrosslinked blank 135 is pressed against the mold 31 while being heated.

[0175] At this time, the uncrosslinked rubber composition sheets 111 flow into the plurality of recesses 32 of the mold 31 while pressing the reinforcing fabric 14 through the core wires 13, and crosslinking occurs. Simultaneously, the core wires 13 and the reinforcing fabric 14 become integrated. As a result, as... Figure 8 As shown, the cylindrical strip blank 35 is formed.

[0176] (4) The internal pressure of the vulcanizing tank is reduced to release the seal. Next, the strip blank 35 formed between the mold 31 and the rubber sleeve 34 is demolded. Then, the demolded strip blank 35 is cut into round pieces. Through this process, the toothed strip 10 is obtained.

[0177] (Manufacturing method of toothed pulley)

[0178] The toothed pulley 20 can be manufactured using methods known in the past.

[0179] The toothed pulley 20 can be manufactured, for example, by making a special hob that corresponds to the shape of the pulley groove of the toothed pulley, then performing tooth cutting on the metal material using the hob, and further performing drilling, shaping, flange installation, etc. as needed.

[0180] (Other implementation methods)

[0181] The teeth of the toothed belt involved in the embodiments of the present invention are not limited to oblique teeth, but can also be straight teeth.

[0182] When the teeth of the toothed belt are straight teeth, the pulley with straight teeth on the outer circumference is also selected as the toothed pulley.

[0183] Example

[0184] The embodiments of the present invention will be described in more detail below through examples, but the embodiments of the present invention are not limited to the following examples.

[0185] Here, we prepare different transmission systems combining toothed belts and toothed pulleys and evaluate the noise levels.

[0186] (toothed band)

[0187] Manufactured with Figures 2-4 The toothed band 10 shown is the same as the toothed band (A).

[0188] With a compression rate of 0%, the width Wb of the toothed belt (A) is 20 mm and the circumference of the belt is 330 mm.

[0189] The toothed belt (A) has oblique teeth with a tooth pitch P of 2 mm and a tooth angle of 5 degrees as belt teeth.

[0190] The tooth height Hb of the toothed belt (A) is 0.76 mm, the total thickness Tb(Hb+Sb) is 2.1 mm, and the tooth width β is 1.044 mm.

[0191] exist Figure 9 In the toothed band dimensions shown, the tooth dimensions of the toothed band (A) are S = 1.3 mm, A = 0.172 mm, and r = 0.172 mm. bb It is 1.3mm. In Figure 9 In Chinese, "S" and "r" bb "Equivalent to "S" and "r" as recorded in Table 4 of JIS B 1857-1 (2015) bb “A” is equivalent to “aY” derived from Table 4 of JIS B 1857-1 (2015).

[0192] In the toothed belt (A), the rubber component of the belt body 11 is EPDM.

[0193] In the toothed belt (A), the core wire 13 is a carbon core wire. The outer diameter φT in the thickness direction and the outer diameter φW in the thickness direction of this carbon core wire are both 0.33 mm.

[0194] In the toothed belt (A), the reinforcing fabric 14 is a woven fabric. The warp and weft of this fabric are polyamide 66 fibers.

[0195] (toothed pulley)

[0196] Toothed pulleys (1) to (21) with different shapes of pulley groove 21 are manufactured.

[0197] The toothed pulleys (1) to (21) are manufactured by making a special hob that corresponds to the shape of the pulley groove of each pulley, and by a manufacturing process including tooth cutting using the hob.

[0198] The toothed pulleys (1) to (21) have a tooth tip circle radius of 12.5 mm and 40 teeth (40T). Two toothed pulleys (1) to (21) are manufactured respectively.

[0199] The width of the toothed pulleys (1) to (21) is 22 mm.

[0200] The toothed pulleys (1) to (21) are made of stainless steel.

[0201] Regarding the dimensions of the grooves of each of the toothed pulleys (1) to (21), in Figure 10In the dimensions of the pulley groove shown, Hp, R1, A, and B g They each have the dimensions shown in Table 1. Figure 10 In the text, "Hp", "R1" and "B" are used. g "Equivalent to "H" recorded in Table 13 of JIS B 1857-2 (2015) g “R1” and “B” g “A” is equivalent to “a-Y1” derived from Table 13 of JIS B 1857-2 (2015).

[0202] (Examples 1-12, Comparative Examples 1-9)

[0203] Using the toothed belt, drive pulley, and driven pulley combinations shown in Tables 1 and 2, the toothed belt is wound onto a double-shaft pulley with a drive pulley and a driven pulley to form a transmission system.

[0204] Figure 11 The pulley layout of the transmission system is shown.

[0205] In this transmission system, the counterweight (SW) is fixed such that the belt tension is 100N. The reduction ratio is set to 1.0.

[0206] (evaluate)

[0207] The aforementioned transmission system was driven at a constant speed of 3000 rpm, and the resulting sounds were identified and ranked into five levels by auditory perception. The results are shown in Tables 1 and 2. Figure 12 As shown.

[0208] In this rating, the lower the numerical value of the ranking, the quieter the environment.

[0209] [Table 1]

[0210]

[0211] [Table 2]

[0212]

[0213] As shown in Tables 1 and 2 Figure 12 As shown, it is clear that by satisfying the specified relationship between the tooth tip compression ratio Y (%) and the tooth width clearance ratio X (%) of the toothed gear, the noise of the transmission system can be suppressed.

[0214] Explanation of symbols

[0215] 1.40 Transmission System

[0216] 10 Toothed Belt

[0217] 11 with main body

[0218] 11a Base

[0219] 11b Tooth

[0220] 12 Toothed

[0221] 13-core wire

[0222] 14 Reinforced Fabric

[0223] 15 teeth bottom

[0224] 20 Toothed Pulley

[0225] 21 Pulley Groove

[0226] 22, 41 Drive pulleys

[0227] 24, 42 Driven pulleys

[0228] 30 molds

[0229] 31 recess

[0230] 32 convex part

[0231] 34 Rubber Sleeve

[0232] 35 strip billet

[0233] 111 Uncrosslinked rubber composition sheet

[0234] 135 Uncrosslinked preform

Claims

1. A toothed belt having a back portion in which a core wire is embedded; and belt teeth disposed on the inner circumferential side of said back portion, engaging with a pulley groove of a toothed pulley. The tooth tip compression ratio Y (%) calculated by equation (1) is -2≤Y≤10. The porosity X (%) in the tooth width direction of the toothed band, calculated by equation (2), is -30 ≤ X ≤ 0. Y(%)=((belt tooth height Hb-pulley tooth groove depth Hp) / belt tooth height Hb)×100···(1) X(%)=((pulley tooth width γ-pulley tooth width β) / pulley tooth width γ)×100··· (2).

2. The toothed belt according to claim 1, wherein, The tooth tip compression ratio Y (%) is 0 ≤ Y ≤ 8, and the void ratio X (%) is -20 ≤ X ≤ -10.

3. The toothed belt according to claim 1 or 2, wherein, The core wire is either a carbon core wire or a steel core wire.

4. The toothed belt according to any one of claims 1 to 3, wherein, The teeth are helical. The angle between the tooth direction of the helical tooth and the bandwidth direction is more than 3 degrees and less than 16 degrees.

5. The toothed belt according to claim 4, wherein, The ratio B of the thickness Sb of the back to the tooth height Hb of the helical tooth is more than 1.75 and less than 2.

40.

6. A transmission system comprising a toothed belt and a toothed pulley engaging with said toothed belt. The toothed belt is the toothed belt according to any one of claims 1 to 5.

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