Multi-wedge high-efficiency belts and methods for manufacturing wedge layer materials for high-efficiency belts

Abstract

A multi-wedge high-efficiency belt and a method for manufacturing a wedge layer material for the high-efficiency belt are disclosed. The multi-wedge high-efficiency belt includes: a backing layer, a wedge material layer disposed on the backing layer, and a rope embedded within the wedge material layer, wherein the coefficient of friction of the high-efficiency belt is greater than or equal to 0.03 N / mm multiplied by the flexural stiffness of the belt with a thickness in the range of 2.6 mm to 4.2 mm. Other characteristics of the high-efficiency belt may include a flexural stiffness in the range of about 30 N / mm to about 65 N / mm and an anisotropic modulus ratio between 1.1 and 5.0. A method for manufacturing the high-efficiency belt is also described, which may include forming a wedge material sheet in a manner that provides parallel-aligned reinforcing fibers. In some embodiments, the sheet forming method provides a sheet wherein the reinforcing fibers are aligned in a direction transverse to the rotational direction of the high-efficiency belt.

Description

[0001] This application is a divisional application of Chinese invention patent application No. 201980027745.8, which is entitled "High-efficiency belt and method of manufacturing the high-efficiency belt" and whose international application date is September 27, 2019, PCT / US2019 / 053644.

[0002] Cross-reference to related applications

[0003] This application claims the benefit and priority of U.S. Provisional Patent Application No. 62 / 737,517, filed September 27, 2018, entitled “High-efficiency belt and method of manufacturing the high-efficiency belt,” the entire contents of which are incorporated herein by reference. Technical Field

[0004] This application relates to belts for use in, for example, automotive powertrains, and more particularly, to belts that are more efficient than previously known belts in reducing the energy required to rotate the belt without sacrificing other performance characteristics of the belt, such as durability and power transmission capacity. Background Technology

[0005] Previously known belts, such as those used in automotive powertrains, require a certain amount of energy to rotate. This energy consumption typically takes the form of delayed heat generation and additional fuel consumption due to the increased torque required to rotate the belt. For various reasons, belts requiring less energy to rotate are ideal. For instance, belts requiring less energy result in improved fuel economy and reduced emissions, both of which are important in vehicle design.

[0006] The energy efficiency of a belt (i.e., the energy required to rotate the belt) depends on many different characteristics of the belt, including but not limited to the materials used in the belt, the belt's mass, the belt's thickness, and the belt's bending stiffness. When manufacturing such belts, a cost-benefit analysis needs to be considered when changing or adjusting one or more of these parameters in an attempt to improve belt efficiency. For example, changing the materials used in the belt and / or changing the belt's thickness may beneficially reduce the energy required to rotate the belt, but may also reduce the belt's durability or have other negative effects on belt performance. Adjusting certain characteristics of the belt may have competing effects (i.e., a positive effect on one aspect of the belt while a negative effect on another). For example, reducing the belt's thickness may beneficially reduce the belt's bending stiffness, making the belt easier to rotate, but may also reduce the coefficient of friction and therefore require more energy to rotate the belt due to reduced torque transmission. Therefore, there is a need for belts that require less energy to rotate without compromising other important belt characteristics, such as those related to performance and durability. There is also a need for methods for manufacturing such efficient belts. Summary of the Invention

[0007] This invention provides a simplified overview of some concepts, which will be further described in the detailed description below. This summary and the foregoing background are not intended to limit the key or essential aspects of the claimed subject matter. Furthermore, this summary is not intended to help determine the scope of the claimed subject matter.

[0008] This application describes various embodiments of belts that have higher energy efficiency than previously known belts without compromising other properties of the belt, as well as embodiments for manufacturing such belts. In some embodiments, the high-efficiency belt includes: a backing layer, a wedge material layer disposed on the backing layer, and a rope embedded within the wedge material layer, wherein the belt's coefficient of friction is greater than or equal to 0.03 mm / N multiplied by the belt's flexural stiffness, for example, a coefficient of friction greater than or equal to 0.04 mm / N multiplied by the flexural stiffness. Other characteristics of the belt product may include: a thickness in the range of about 2.6 mm to about 4.2 mm, for example, between about 3.0 mm and about 3.8 mm; a flexural stiffness in the range of about 30 N / mm to about 65 N / mm; and an anisotropic modulus of elasticity between 1.1 and 5.0. Further features of the belt may include a backing layer surface with a finned heat exchanger design, which helps to extend the ambient operating temperature range of the disclosed high-efficiency belt.

[0009] In some embodiments, a method for manufacturing a high-efficiency belt generally includes: mixing various raw materials together; milling or extruding the mixture to form a sheet; calendering the sheet to form a calendered sheet; bannering segments of the calendered sheet together; slab-building a composite belt structure on a die, the composite belt structure including the bannered sheet material; curing the composite belt material in the die; and various optional post-processing steps to produce the desired finished belt from the cured material. In some embodiments of the above method, specific raw materials are used in specific amounts to produce sheet material with anisotropic properties relative to the modulus of elasticity. In some embodiments, calendering is used to homogenize the reinforcing material within the sheet. In some embodiments, the bannering step requires joining the individual sheets together such that all reinforcing materials are aligned in the same direction, and more particularly, in the non-bending direction of the belt.

[0010] These and other aspects of the high-efficiency belt described herein will become apparent upon consideration of the specific embodiments and accompanying drawings. However, it should be understood that the scope of the claimed subject matter should be determined by the promulgated claims, and not by whether the given subject matter solves any or all of the problems mentioned in the background art or includes any features or aspects recited in the summary of the invention. Attached Figure Description

[0011] Non-limiting and non-exhaustive embodiments of the disclosed high-efficiency belt, including preferred embodiments, will be described with reference to the following figures, wherein similar reference numerals refer to similar parts throughout the various views unless otherwise stated.

[0012] Figure 1 This is a flowchart illustrating a method for manufacturing a high-efficiency belt according to various embodiments described herein.

[0013] Figure 2 This is a schematic diagram of the bonding steps used in the manufacturing methods according to the various embodiments described herein.

[0014] Figure 3A and 3B These are cross-sectional views of a previously known belt and a high-efficiency belt according to the embodiments described herein.

[0015] Figure 4A and 4B These are graphs showing the effects of temperature and belt thickness on the resistance to bending stiffness in the high-efficiency belts according to the various embodiments described herein.

[0016] Figure 5A and 5BThese are bar charts showing the bending stiffness of belts with various thicknesses (in mm) previously known and the bending stiffness of belts with various thicknesses (in mm) according to various embodiments disclosed herein.

[0017] Figure 6 This is a graph showing the relationship between the bending stiffness and the coefficient of friction of previously known belts and belts according to the various embodiments described herein.

[0018] Figure 7 This is a graph showing the power loss of belts according to various embodiments described herein, at various pulley diameters, compared to previously known belts.

[0019] Figure 8 It is the structure of the pulley for testing the coefficient of friction (COF). Detailed Implementation

[0020] Embodiments are described more fully below with reference to the accompanying drawings, which form part of this specification and illustrate specific exemplary embodiments by way of illustration. These embodiments are disclosed in sufficient detail to enable those skilled in the art to practice the invention. However, embodiments may be implemented in many different forms and should not be construed as limited to the embodiments set forth herein. Therefore, the following detailed description should not be considered restrictive.

[0021] Reference Figure 1 A method 100 for manufacturing a high-efficiency belt generally includes: a step 110 of mixing raw materials together; a step 120 of milling or extruding the mixture to form a sheet; a step 130 of calendering the sheet; a step 140 of combining multiple calendered sheets together; a step 150 of constructing a belt on a slab using at least the combined sheets; a step 160 of curing the belt structure in the mold; a step 170 of removing the cured cylinder from the mold and cutting the cylinder into multiple individual belts; and an optional step 180 of grinding and contouring the belt to its final size (as needed). Figure 1 The belt produced by the method shown is a high-efficiency belt that requires less energy to rotate compared to known belts of similar dimensions (e.g., thickness). Of particular interest, and as described in more detail below, is the belt produced by… Figure 1 The method shown produces a high-efficiency belt with an anisotropic material structure with respect to its elastic modulus and improved (i.e., reduced) bending stiffness, both of which contribute to increased belt efficiency.

[0022] In step 110, the raw materials are mixed together to form a mixture. The raw materials mixed together in step 110 generally include: 1) a base elastomer or rubber raw material, 2) a reinforcing material, 3) a filler material, 4) an oil, and 5) a vulcanizing agent. Plasticizers, anti-degradation agents, colorants, processing aids, auxiliaries, etc. may also be optionally added.

[0023] In some embodiments, an industrial mixer, such as a Banbury mixer, is typically used to perform mixing step 100 to mix all the ingredients together. However, other mixing techniques and methods may also be used. In some embodiments, the various ingredients are added to the mixer in a specific order to ensure adequate cohesion and dispersion of the ingredients. In some embodiments, certain ingredients may be mixed together before being added to the mixture in sequence. Exemplary but non-limiting mixing sequences that may be used include adding the polymer, carbon black, and oil first; then the fibers and fillers; followed by the vulcanizing agent.

[0024] Regarding the rubber raw material, any suitable rubber raw material can be used. In some embodiments, the rubber raw material is in the form of powder, pellets, bundles, or blocks. Suitable exemplary rubber raw materials include, but are not limited to, natural rubber, styrene-butadiene rubber (SBR), chloroprene rubber (CR), ethylene propylene elastomers (EPDM and EPM) and other ethylene-elastomer copolymers (e.g., ethylene butene (EBM), ethylene pentene and ethylene octene (EOM)), hydrogenated nitrile butadiene rubber (HNBR), and fluorinated elastomers (FKM). In some embodiments, the amount of rubber raw material used in step 110 is 30 wt% to 70 wt% of the total weight of the mixed composition. In some embodiments, the rubber raw material is about 40 wt% to 60 wt% of the total weight of the mixed composition.

[0025] Regarding the reinforcing material, some embodiments of the methods described herein use chopped fiber segments as the reinforcing material, but other reinforcing materials may also be used, as long as the reinforcing material is in the form of elongated segments. When chopped fibers are used, the chopped fibers may be, for example, aramid, polyester (PET), cotton, or nylon. The chopped fibers may be made of organic or synthetic materials, or a mixture of organic and synthetic materials. The chopped fiber material may also be in the form of carbon fiber nanotubes. The size of the chopped fibers used in step 110 is generally not limited. In some embodiments, the reinforcing material is a high aspect ratio material with a length ranging from 0.2 mm to 3 mm. In some embodiments, the aspect ratio of the reinforcing material (e.g., chopped fibers) is from 10 to 250. In some embodiments, the amount of reinforcing material (e.g., chopped fibers) used in step 110 is from 5 wt% to 30 wt% of the total weight of the mixed composition. In some embodiments, the reinforcing material is from about 6 wt% to about 14 wt% of the total weight of the mixed composition.

[0026] Regarding fillers, some embodiments of the methods described herein use carbon black as a filler; however, other fillers may also be used alone or in combination with carbon black. Other fillers suitable for step 110 include, but are not limited to, clay, pulp, and silica. In some embodiments, the amount of filler used in step 110 is from 5 wt% to 45 wt% of the total weight of the mixed composition. In some embodiments, the filler is from about 10 wt% to about 20 wt% of the total weight of the mixed composition.

[0027] Regarding the oil, it is typically provided as a liquid or binder material as an ingredient, allowing other dry ingredients to be mixed together to form a thick mixture that can be formed into sheets. Any suitable oil can be used, including but not limited to aromatic, naphthenic, and paraffinic oils. In some embodiments, the amount of oil used in step 110 is from 2 wt% to 18 wt% of the total weight of the mixed composition. In some embodiments, the oil is from about 2 wt% to about 8 wt% of the total weight of the mixed composition.

[0028] Regarding the vulcanizing agent, any suitable vulcanizing agent material can be used, wherein the auxiliary role of the vulcanizing agent during curing step 150 is described in more detail below. Exemplary vulcanizing agents suitable for step 110 include, but are not limited to, sulfur and peroxides. In some embodiments, the amount of vulcanizing agent used in step 110 is less than about 8 wt% of the total weight of the mixed composition, for example, less than 5 wt%.

[0029] Table 1 lists exemplary weight percentage ranges of the components of the mixture from step 110.

[0030]

[0031] Table 1

[0032] U.S. Patent Nos. 5,610,217 and 6,616,558 provide additional information regarding material formulations and mixing methods for forming mixtures used in forming belts, some or all of which may be used in the mixing step 110 described herein. Therefore, U.S. Patent Nos. 5,610,217 and 6,616,558 are incorporated herein by reference in their entirety.

[0033] After performing the mixing step 110 as described above, a milling or extrusion step 120 is performed to form a sheet from the mixture. Any standard milling or extrusion technique can be used. In some embodiments, the mixture is cooled to room temperature before milling or extrusion to form the sheet. The resulting sheet has a relatively high surface area.

[0034] While the sheet is being formed in step 120, a calendering step 130 is performed on the sheet. The calendering step 130 serves two main purposes: to reduce and precisely control the thickness of the sheet; and to orient the reinforcing material so that all high aspect ratio reinforcing materials are aligned in the same direction within the sheet, thereby providing the sheet with anisotropic material properties (discussed in more detail below).

[0035] Any known technique for calendering materials can be used, including passing sheet material through rotating drums with a spacing smaller than the thickness of the sheet material, such that the thickness of the sheet material decreases as it passes through the drums. In some embodiments, calendering step 130 is used to reduce the thickness of the sheet produced in step 110 to within a thickness of approximately 0.25 mm to 1.5 mm. Reducing the thickness to the target thickness helps ensure that, during the slab construction process of step 150 (described in more detail below), the sheet can be wound around the cylindrical die multiple times (e.g., 3 times), but the resulting cumulative thickness is still approximately the desired final thickness of the wedge material portion of the finished belt.

[0036] To achieve reinforcement alignment from calendering step 120, the calendering process can utilize shear forces, for example, by operating the two drums at different angular velocities. For instance, when the angular velocity ω1 of the first (e.g., upper) drum is less than the angular velocity ω2 of the second (e.g., lower) drum, this difference in angular velocity applies shear forces to the sheet passing through the drums, causing the reinforcement materials to become aligned within the sheet. That is, all the high aspect ratio reinforcement materials are aligned substantially parallel to each other within the sheet.

[0037] Aligning the reinforcing material in this way results in an anisotropic property of the calendered sheet with respect to its elastic modulus. Generally, the sheet has a first elastic modulus (high shear) in the "coaxial" direction and a second elastic modulus in the "transverse" direction. Combined, the sheet can be considered to have an elastic modulus ratio, which is the ratio of the modulus in the coaxial direction to the modulus in the transverse direction. In some embodiments, the modulus ratio of the sheet produced in step 110 is from 1.1 to 5.0.

[0038] In step 140, the individual sheets formed in steps 120 and 130 are joined together (sometimes referred to as bannering). As used herein, the term "bannering" refers to joining the individual sheets of calendered sheet material end-to-end to form a new, larger sheet. Figure 2 The result of this bonding process is shown, in which multiple individual sheets 201 are pieced together to form a composite (i.e., bonded) sheet 200. In some embodiments and as shown... Figure 2As shown, each sheet will have the same length, such that when the sheets are placed side by side, the upper edge 201a and lower edge 201b of each sheet are aligned. When each sheet 201 is aligned side by side, each sheet 201 is oriented such that the reinforcing material 203 from one sheet 201 to the next is aligned. More specifically, the sheets 201 are aligned such that the reinforcing material 203 is aligned perpendicular to the direction in which the sheets 201 are arranged side by side. For example, Figure 2 An embodiment is shown in which the reinforcing materials 203 are parallel to each other and aligned in a direction perpendicular to the direction in which the sheets 201 are arranged side-by-side. Ultimately, the individual belts formed from these combined sheets 200 will have reinforcing materials aligned in the non-bending direction of the belt. This allows the reinforcing materials to increase the lateral modulus when the belt is compressed at the weft, while decreasing the longitudinal modulus when the belt flexes, providing higher load-bearing capacity while maintaining flexibility.

[0039] During the joining step 140, any method can be used to attach adjacent segments together. In some embodiments, adjacent segments are stitched or sewn together, although other attachment methods may also be used, such as by using adhesives. The length and width dimensions of each segment of the sheet material attached together to form a new bond are generally not limited and will generally be selected based on the desired final dimensions of the belt product formed from the sheet material. The individual sheets joined together can have the same dimensions, or the width of each sheet can vary (the length between each sheet is preferably the same, such that when described above and as...). Figure 2 As shown, when the sheets are joined together, the top and bottom edges are aligned.

[0040] Now that a sheet containing the raw materials of step 110 and having the desired combination with anisotropic properties regarding the modulus of elasticity has been created, step 150 of slab construction of the composite structure of the belt on a mold can be performed. The slab construction process typically requires sequentially providing each layer of the composite belt structure on the mold so that the mold can be closed and exposed to pressure and / or temperature to activate the vulcanizing agent to form a near-finished belt product.

[0041] In some embodiments, the mold on which the slab building process is performed is a cylindrical drum with a diameter approximately equal to the diameter of the belt being formed. There is no specific limitation on the diameter, and it can be any diameter required for the belt product.

[0042] In some embodiments, the first layer to be arranged on the drum mold is a backing material. Any backing material suitable for belt construction can be used. Similarly, the thickness of the backing material is not limited and can be adjusted based on the desired thickness of the backing layer of the resulting belt. In some embodiments, the backing material is a rubber material, though typically different from the rubber material of the bonded sheet obtained in step 140. In other embodiments, the backing material may include one or more of fabric, adhesive rubber, or similar materials. Preferably, the thickness of the backing material is reduced. The uniformity of a thinner backing material enables the previously mentioned improved rope concentricity.

[0043] After the backing material is placed on the drum mold, the slab construction process typically requires winding a rope material around the backing material on the cylindrical drum. A single layer of rope is typically wound around the backing layer and across the entire length of the backing material. Parameters such as the winding angle, winding tension, and spacing between adjacent rope windings can be adjusted according to the needs of the finished product. The rope material wound around the drum mold is generally unrestricted and, in some embodiments, may include metals, aramids, carbon fibers, nylon, polyester, glass, ceramics, and various composite materials, and may include mixtures of materials. The dimensions of the rope itself (e.g., diameter) are unrestricted and can be selected based on the desired end application of the belt.

[0044] After the rope material is wound around the backing material, the slab construction process in step 150 includes winding the bonded sheet material obtained in step 140 around the drum mold and onto the rope and backing material. One or more layers of bonded sheet material may be applied to provide the total thickness of the wedge material portion of the belt made of bonded sheet material, for example, three layers (i.e., the bonded sheet material may be wound around the drum three times). An optional adhesive layer may be applied immediately adjacent to the rope before winding the bonded sheet material.

[0045] The final optional surface layer can then be applied to the bonded sheet material to complete the slab construction process of step 150. The surface layer can be any suitable surface layer material for belt applications, such as braided tubing and polyethylene film. The thickness of the surface layer is generally unrestricted and can be adjusted based on the specific application of the belt being formed.

[0046] After the slab construction process is complete, an external mold can be applied to enclose the composite belt structure between the inner portion (drum cylinder) and the outer portion of the mold. The outer portion of the mold is typically cylindrical, mirror-shaped to the drum cylinder, to enclose the composite belt structure and form a belt of uniform thickness. In embodiments where the formed belt does not have teeth, wedges, or the like, the outer mold may have a flat inner surface. Alternatively, the inner surface of the outer mold may include a profile that will produce any teeth, wedges, etc., required for the belt product, including providing the generally required size, shape, and spacing for the wedges or teeth. In some embodiments, the high-efficiency belt described herein includes wedges. The high-efficiency belt described herein may include cross-cuts, notches, and other types of surface modifications.

[0047] The outer surface of the inner mold can be used to add patterns, such as heat exchanger fins, to the backing of the belt. For example, in some embodiments of the belt described herein, the manufacturing method includes the step of forming finned heat exchanger elements on the outer side of the backing material. These finned heat exchanger elements help dissipate heat from the belt and further improve belt performance and increase the temperature range over which the belt can be used. Any suitable finned element, including any pattern, can be used for heat dissipation. In some embodiments, the height of the finned element is from about 0.2 mm to about 10 mm.

[0048] In step 160, a curing process is performed to crosslink the polymer formulation, densify the product, and provide performance characteristics. The curing process is generally unrestricted and can be similar to or the same as known curing techniques, such as applying heat and / or pressure to activate the vulcanizing agent in the belt material. In some embodiments, steam is used specifically for the curing step, although non-steam methods may also be used. As noted in the discussion of step 110, the belt may include a vulcanizing agent that facilitates the curing process and crosslinks the polymer material to form a belt with the desired final material properties and dimensions.

[0049] In step 170, the belt material is removed from the mold by removing the outer mold portion and then by sliding the cured belt material off the drum cylinder. The resulting product is an elongated cylinder with a composite belt structure. To form individual belts from this cylinder, the cylinder is cut transversely to its axis to form thinner loops of belt material, each loop having the desired width of the final belt product.

[0050] Finally, in step 180, if necessary, any grinding and contouring required to bring the individual belt segments to their final dimensions is performed. Grinding and / or contouring in any manner may be used. In some embodiments, grinding and / or contouring are performed to, for example, adjust the thickness of the belt and / or refine the dimensions of any teeth or wedges formed in the belt. However, it is particularly noteworthy that the amount of machining and / or grinding required can be significantly reduced or eliminated based on the method described herein for manufacturing high-efficiency belts compared to previously known manufacturing methods.

[0051] Reference Figure 3A and 3B This shows the previously known belt 300 ( Figure 3A ) and belt 350 manufactured according to method 100 Figure 3B A cross-sectional view of ( ). For example... Figure 3A and 3B As shown, previously known belts have a relatively large overall thickness, for example, about 4.3 mm, while the belt 350 described herein can have a thickness, for example, in the range of about 3.2 mm to 3.5 mm. The belt 350 of this technology generally includes a backing layer 360, a cord 370, a wedge material 380 (formed from multiple layers of the aforementioned sheet material), and a surface layer 390. Figure 3B As shown, belt 350 includes wedge 355; however, it should be understood that belt 350 may or may not include teeth, wedges, or similar surface modifications. The thickness reduction may originate partly from a thinner backing layer and partly from a shallower wedge. The majority of the thickness reduction likely originates from the shallower wedge.

[0052] The thickness of the belts described herein may vary depending on the specific application of the belt. In some embodiments, the belt thickness varies between about 2.6 mm and about 4.2 mm. In some embodiments, the belt thickness is in the range of about 3.0 mm to 3.8 mm, for example, in the range of about 3.2 mm to about 3.5 mm.

[0053] Although the methods 100 and 100 described above Figure 3B The belt construction shown generally describes and illustrates a belt with a backing layer / rope / wedge material layer / surface layer construction; however, it should be understood that alternative belt constructions incorporating the wedge material described herein may also be used. For example, the belt construction may include a rubber material (e.g., a rubber composition different from the wedge material) between the rope and the backing material (including when the backing material is made of fabric), the belt construction may include transverse rope material as the backing material, and / or the belt construction may include additional layers, such as an adhesive layer surrounding the rope but different from the wedge material.

[0054] Reference Figure 4A and 4BBased on parameters such as temperature and belt thickness, belts described herein and manufactured according to the methods and materials described herein will have variable bending stiffness. See details... Figure 4A The graph showing the relationship between the bending stiffness of a 4.2mm thick belt and temperature indicates that the bending stiffness of the belt decreases as temperature increases. (Refer to...) Figure 4B A graph showing the relationship between bending stiffness and belt thickness indicates that bending stiffness increases with increasing belt thickness. This generally suggests that thinner belts are desirable because the correspondingly reduced bending stiffness will make the belt easier to turn. However, as discussed in more detail below, reduced thickness can also decrease the belt's coefficient of friction (COF), a measure of the belt's ability to transmit torque. Therefore, this reduction in COF is generally undesirable because it decreases the belt's torque-transmitting capacity, potentially requiring additional power to turn the pulleys. As previously mentioned, reduced belt thickness also reduces belt durability. Therefore, simply reducing belt thickness usually does not solve the problem of providing efficient belts.

[0055] Figure 5A and 5B Furthermore, it is shown that the belt described herein has comparable bending stiffness compared to previously known belts with similar thickness, and that the belt described herein, with a reduced thickness compared to previously known belts, has improved bending thickness. Figure 5A Measurements of the bending stiffness of various previously known belts are shown, each with a thickness ranging from approximately 4.2 mm to approximately 5.0 mm. It can be seen that the bending stiffness of these previously known belts ranges from approximately 50 N / mm to approximately 80 N / mm. For previously known belts with bending stiffness at the higher end of this range, more power is required to rotate the belt, resulting in lower energy efficiency. Smaller thicknesses are generally not used in previously known belts because, although it is recognized that thinner belts can provide reduced bending stiffness and thus improve power transmission efficiency, reducing the thickness of these belts reduces belt life to unacceptable levels and negatively impacts the belt's torque transmission performance.

[0056] Figure 5BThe bending stiffness measurements of various belts manufactured and constructed according to the embodiments described herein are shown. The tested belts had three different thicknesses: 4.2 mm (similar to previously known belts); 3.4 mm; and 2.6 mm. It can be seen that the bending stiffness of the 4.2 mm belt generally ranges from about 55 N / mm to 65 N / mm, thus being comparable to the performance of previously known belts with similar thicknesses. At a thickness of 3.4 mm, the bending stiffness ranges from about 35 N / mm to about 50 N / mm. At a thickness of 2.6 mm, the bending stiffness ranges from about 30 N / mm to 35 N / mm. Therefore, from the perspective of improved power transmission efficiency, these thinner belts exhibit excellent bending stiffness measurements.

[0057] Figure 6 The bending stiffness of previously known belts is shown, plotted against the effective coefficient of friction (COF) for each belt. Figure 6 The thickness of all previously known belts shown is generally in the range of 4.2 mm, and thus the reduced bending stiffness is achieved through adjustments such as material selection and quantity. Data points for previously known belts (shown as diamond-shaped plots) show that the COF decreases with decreasing bending stiffness, thus demonstrating the traditionally present negative consequences associated with reduced bending stiffness (i.e., while reduced bending stiffness theoretically makes the belt easier to rotate, reduced COF means the belt is less efficient at transmitting torque to the pulleys). The data points for previously known belts also show that they generally adhere to a relationship between the coefficient of friction and bending stiffness, where the coefficient of friction is less than or equal to approximately 0.02 N / mm multiplied by the bending stiffness.

[0058] In contrast, for the belts described in this article Figure 6 The data shown in the graph demonstrates that a relatively high COF value is achieved even with reduced bending stiffness. In other words, the belts described herein largely overcome the problem that reduced bending thickness also leads to an undesirable decrease in COF. In some embodiments, the COF of the belts described herein is greater than or equal to 0.03 N / mm multiplied by the belt's bending stiffness, for example, COF greater than or equal to 0.04 N / mm multiplied by the bending stiffness. Figure 6This includes trend lines 601 and 602 for COF values ​​greater than or equal to 0.03 N / mm multiplied by the bending stiffness. In some embodiments, the COF value is greater than 0.03 N / mm multiplied by the bending stiffness, less than 0.06 N / mm multiplied by the bending stiffness, or less than 0.05 N / mm multiplied by the bending stiffness. This relationship between COF and bending stiffness shows that the belts described herein provide a high efficiency belt by maintaining a high COF (compared to previously known belts at similar bending stiffness) while providing reduced bending stiffness. The high efficiency belts described herein that follow this relationship avoid the need for the additional effort required to handle high bending stiffness or reduce COF that is experienced by prior art belts.

[0059] Figure 7 This is a graph further illustrating the improved performance of the belt described herein compared to previously known belts. The graph compares the power loss experienced by the high-efficiency belt described herein with that of a previously known belt of the same thickness under various pulley diameter conditions. Figure 7 As shown, power loss increases as the pulley diameter of both types of belts decreases, but under each pulley diameter condition, the power loss in the high-efficiency belt is significantly less than that of previously known belts.

[0060] Various benefits can be achieved through the high-efficiency belts and manufacturing methods described herein. For example, the high-efficiency belts described herein can be provided with a thickness smaller than that of previously known belts (e.g., 3.0 mm to 3.8 mm compared to a previously known belt with a thickness of about 4.2 mm) without suffering performance degradation (e.g., no reduction in torque transmission). By reducing the belt thickness, less material is used in the belt, which means a smaller belt mass. In some embodiments, the belts described herein have a mass 5% to 40% less than that of previously known belts while having comparable or better performance. The reduction in both material and mass helps to make the belt more efficient in requiring less rotational energy. Importantly, the thinner belts provide similar or equal durability to thicker previously known belts while still exhibiting comparable or better energy efficiency. The thinner belts also reduce waste, meaning less material ends up in landfills. Similarly, due to the reduced belt mass, the disposal costs associated with the belts described herein are reduced.

[0061] The belt of this application also exhibits improved bending stiffness (e.g., due to the thinner belt), which further contributes to improved belt efficiency. As previously mentioned, reduced bending stiffness characteristics are achieved while still maintaining a high coefficient of friction, meaning the belt is both easy to bend and rotate, and provides good torque transmission characteristics. This combination provides a highly efficient belt for applications requiring reduced power consumption.

[0062] Another feature of the belt disclosed herein is improved rope concentricity. Rope concentricity generally refers to the deviation of each rope from the centerline. In some previously known belts, rope concentricity may be 0.30 mm or higher, meaning that each rope within the belt may deviate from the centerline (and thus from other nearby ropes) by up to 0.30 mm. In the belt described herein, rope concentricity is generally limited to 0.1 mm to 0.2 mm, thus providing more aligned ropes within the belt.

[0063] The belts described herein also feature an improved operating temperature range. In some embodiments, the belts can be used in a temperature range of -40°C to 130°C. Although the material will still begin to degrade at known temperatures above the ambient temperature, the reduction in hysteresis heat generation allows the belt to operate with a lower temperature difference, which would allow the ambient temperature to rise. Additionally, the thinner belts described herein exhibit less hysteresis heat generation and operate cooler. The thinner belts are also easier to cool, which further contributes to improved belt energy efficiency. The thinner cross-section also provides for belts with better strain at the belt ends, providing yet another property leading to better energy efficiency.

[0064] Other features of belts that contribute to improved energy efficiency include less flexural fatigue, lower hysteresis accumulation, and lower reinforcement requirements for equivalent performance.

[0065] The improved energy efficiency exhibited by the belts described in this article also allows for improvements in system design and application. The slim design and lower bending stiffness allow for increased flexibility, resulting in smaller bending radius pulleys. Smaller pulley radii improve packaging requirements and reduce system mass and inertial loads. The slim structure allows operation at higher speeds. Therefore, cost savings are achieved through corresponding weight reduction and packaging improvements.

[0066] The belts described herein utilize a thinner cross-section design to provide the aforementioned energy efficiency improvements without significantly impacting durability. In some embodiments, the improved cooling of the aforementioned belts helps maintain belt durability. The belts are also able to utilize shorter tooth heights, resulting in lower strain energy density and thus fewer cracks. The belts described herein also exhibit greater durability in start-stop applications.

[0067] The belt structure described herein can also provide benefits such as the ability to use alternative reinforcing materials, such as, but not limited to, aramids, glass, carbon fiber ropes, hybrid ropes, metals, ceramics, and plastics.

[0068] Other advantages associated with the construction of the belt disclosed herein include the use of a thinner tensile layer, the implementation of a material with a lower strain modulus, and reduced rope misalignment due to the thinner profile of the belt.

[0069] Bending stiffness and coefficient of friction

[0070] The flexural stiffness of the belt as referred to in this specification and claims can be measured in a three-point dynamic bending test on a portion of the belt. All reported stiffness results are based on testing a 6-wedge belt in a constant deflection mode at room temperature, 1 Hz frequency, 5 N preload, and 0.25 mm deflection on a dynamic mechanical testing apparatus. The flexural stiffness result is the dynamic stiffness K*, expressed in N / mm. Samples can be cut from the belt. The tests described herein used 3-inch (75 mm) long belt samples with two supports spaced 2 inches (50 mm) apart for the flexural stiffness test.

[0071] The effective coefficient of friction or COF referred to in this specification and claims can be measured according to the standard test procedures described in SAE J2432, MAR2015, "Performance Testing of PK Section V-Ribbed Belts" §10. Figure 8 The COF test setup is shown. (Refer to...) Figure 8 Both the driven test pulley 122 and the drive pulley 121 have a multi-V wedge profile and a diameter of 121.6 mm. Pulleys 123, 124, and 126 are idler pulleys. These pulleys are positioned to maintain a 20-degree wrap angle on the driven pulley 122. The drive pulley 121 rotates at 400 rpm. A weight W of 360 N is applied to pulley 125 to provide a slack-side belt tension of 180 N on pulley 125. Torque is applied to the test pulley 122, gradually increasing from zero torque until the pulley stops rotating. The coefficient of friction (COF) is calculated based on the observed maximum torque. It should be understood that this test measures the effective coefficient of friction on the belt, which does not numerically match the theoretical coefficient of friction.

[0072] Example

[0073] Various embodiments of the techniques described herein are illustrated in the following non-limiting examples.

[0074] Example 1. A multi-wedge high-efficiency belt, the multi-wedge high-efficiency belt comprising:

[0075] Backing layer;

[0076] A wedge material layer set on the backing layer;

[0077] Multiple ropes embedded in the wedge material; and

[0078] Multiple wedges formed on the surface of the belt opposite to the backing layer;

[0079] Among them, the coefficient of friction of the high-efficiency belt is greater than or equal to 0.03 N / mm multiplied by the bending stiffness of the high-efficiency belt; and

[0080] Among them, the thickness of the high-efficiency belt is less than about 3.8 mm.

[0081] Example 2. The high-efficiency belt according to Example 1, wherein the coefficient of friction of the high-efficiency belt is greater than or equal to 0.04 N / mm multiplied by the bending stiffness of the high-efficiency belt.

[0082] Example 3. The high-efficiency belt according to any of the foregoing examples, wherein the thickness of the high-efficiency belt is from about 3.0 mm to about 3.8 mm.

[0083] Example 4. The high-efficiency belt according to any of the preceding examples, wherein the coefficient of friction of the high-efficiency belt is greater than or equal to 0.03 N / mm multiplied by the bending stiffness of the high-efficiency belt, and less than or equal to 0.05 N / mm multiplied by the bending stiffness of the high-efficiency belt.

[0084] Example 5. The high-efficiency belt according to any of the foregoing examples, wherein the thickness of the high-efficiency belt is about 3.4 mm and the bending stiffness is in the range of about 35 N / mm to about 50 N / mm.

[0085] Example 6. The high-efficiency belt according to any of the foregoing examples, wherein the material of the wedge material layer comprises:

[0086] Approximately 30 wt% to approximately 70 wt% of rubber raw materials;

[0087] Reinforcing material of about 5 wt% to about 30 wt%; and

[0088] Approximately 5 wt% to approximately 45 wt% of filler.

[0089] Example 7. The high-efficiency belt according to any of the foregoing examples, wherein the rubber raw material is selected from the group consisting of natural rubber, styrene-butadiene rubber (SBR), chloroprene rubber (CR), ethylene propylene diene monomer rubber (EPDM) or other ethylene elastomer copolymers, hydrogenated nitrile butadiene rubber (HNBR), fluorinated elastomers and combinations thereof.

[0090] Example 8. The high-efficiency belt according to any of the preceding examples, wherein the reinforcing material comprises elongated segments, and the elongated segments are aligned parallel to each other within the wedge material.

[0091] Example 9. The high-efficiency belt according to any of the preceding examples, wherein the elongated segment is a chopped fiber segment.

[0092] Example 10. The high-efficiency belt according to any of the preceding examples, wherein the parallel-aligned reinforcing materials are aligned transversely to the rotational direction of the high-efficiency belt.

[0093] Example 11. The high-efficiency belt according to any of the foregoing examples, wherein the filler is selected from the group consisting of carbon black, clay, pulp, silica and combinations thereof.

[0094] Example 12. The high-efficiency belt according to any of the foregoing examples, wherein the high-efficiency belt has an anisotropic elastic modulus.

[0095] Example 13. The high-efficiency belt according to any of the preceding examples, wherein the elastic modulus in the direction of the reinforcing material alignment is greater than the elastic modulus in the direction transverse to the direction of the reinforcing material alignment.

[0096] Example 14. The high-efficiency belt according to any of the preceding examples, wherein the ratio of the elastic modulus in the direction of the reinforcing material alignment to the elastic modulus in the direction transverse to the direction of the reinforcing material alignment is in the range of 1.1 to 5.0.

[0097] Example 15. A method for manufacturing a wedge material for high-efficiency belts, the method comprising:

[0098] Rubber raw materials, reinforcing materials, fillers and vulcanizing agents are mixed to form a mixture, wherein the reinforcing materials include elongated segments;

[0099] Sheets are formed from mixtures;

[0100] Processing the sheet to align elongated segments of the reinforcing material in parallel and form anisotropic sheets; and

[0101] To combine two or more anisotropic sheets together.

[0102] Example 16. The method according to Example 15, wherein the mixture comprises:

[0103] Approximately 30 wt% to approximately 70 wt% of rubber raw materials;

[0104] Reinforcing material of about 5 wt% to about 30 wt%; and

[0105] Approximately 5 wt% to approximately 45 wt% of filler.

[0106] Example 17. The method according to Example 15 or 16, wherein the elongated segments of the reinforcing material comprise chopped fibers, and wherein processing the sheet to align the elongated segments of the reinforcing material in parallel and form an anisotropic sheet comprises calendering the sheet.

[0107] Example 18. The method according to any of Examples 15-17, wherein joining two or more anisotropic sheets together comprises: placing two anisotropic sheets side by side, wherein elongated segments of reinforcing material are parallel to each other and aligned in a direction perpendicular to the direction in which the anisotropic sheets are arranged side by side; and securing the two anisotropic sheets together.

[0108] Example 19. The method according to any of Examples 15-18, wherein a wedge material is incorporated into a high-efficiency belt.

[0109] Based on the foregoing, it will be understood that while specific embodiments of the invention have been described herein for illustrative purposes, various modifications may be made without departing from the scope of the invention. Therefore, the invention is not limited to the appended claims.

[0110] Although the technology has been described in language specific to certain structures and materials, it should be understood that the invention as defined in the appended claims is not necessarily limited to the specific structures and materials described. Rather, specific aspects are described as forms of implementing the claimed invention. Because many embodiments of the invention can be practiced without departing from the spirit and scope of the invention, the invention exists within the appended claims.

[0111] Unless otherwise stated, all numbers or expressions used in this specification (except for the claims), such as those describing dimensions, physical properties, etc., should in any case be understood to be modified by the term "about". At least and without attempt to apply the principle of equivalence to the claims, each numerical parameter modified by the term "about" in the specification or claims should be interpreted at least according to the number of significant figures stated and by applying rounding techniques. Furthermore, all scopes disclosed herein should be understood to cover and support claims that include any and all sub-scopes or any and all individual values ​​contained therein. For example, the range 1 to 10 should be considered to include and support claims that include any and all sub-scopes or individual values ​​between a minimum value of 1 and a maximum value of 10 and / or include a minimum value of 1 and a maximum value of 10; that is, all sub-scopes begin with a minimum value of 1 or greater and end with a maximum value of 10 or less (e.g., 5.5 to 10, 2.34 to 3.56, etc.) or any value from 1 to 10 (e.g., 3, 5.8, 9.9994, etc.).

Claims

1. A multi-wedge high-efficiency belt, comprising: Backing layer; A wedge material layer disposed on the backing layer; Multiple ropes embedded within the wedge material; and Multiple wedges formed on the surface of the belt opposite to the backing layer; Wherein, the coefficient of friction of the high-efficiency belt is greater than or equal to 0.03 mm / N multiplied by the bending stiffness of the high-efficiency belt; The thickness of the high-efficiency belt is 3.0 mm to 3.8 mm; The materials of the wedge material layer include: 30wt% to 70wt% of rubber raw materials; 5 wt% to 30 wt% of reinforcing materials; and 5wt% to 45wt% of filler; The reinforcing material includes elongated segments, and the elongated segments are aligned parallel to each other within the wedge material. The parallel-aligned reinforcing materials are aligned transversely to the rotation direction of the high-efficiency belt; The high-efficiency belt has an anisotropic elastic modulus; and The ratio of the elastic modulus in the direction in which the reinforcing material is aligned to the elastic modulus in the direction transverse to the direction in which the reinforcing material is aligned is in the range of 1.1 to 5.

0.

2. The high-efficiency belt according to claim 1, wherein, The coefficient of friction of the high-efficiency belt is greater than or equal to 0.03 mm / N multiplied by the bending stiffness of the high-efficiency belt, and less than or equal to 0.05 mm / N multiplied by the bending stiffness of the high-efficiency belt.

3. The high-efficiency belt according to claim 1, wherein, The high-efficiency belt has a thickness of 3.4 mm and a bending stiffness in the range of 35 N / mm to 50 N / mm.

4. The high-efficiency belt according to claim 1, wherein, The rubber raw materials are selected from the group consisting of natural rubber, styrene-butadiene rubber (SBR), chloroprene rubber (CR), ethylene propylene diene monomer rubber (EPDM), hydrogenated nitrile butadiene rubber (HNBR), ethylene copolymer elastomers, fluorinated elastomers, and combinations thereof.

5. The high-efficiency belt according to claim 1, wherein, The elongated segment is a short-cut fiber segment.

6. The high-efficiency belt according to claim 1, wherein, The filler is selected from the group consisting of carbon black, clay, pulp, silica, and combinations thereof.

7. A method for manufacturing a wedge material for high-efficiency belts, the method comprising: Rubber raw materials, reinforcing materials, fillers and vulcanizing agents are mixed to form a mixture, wherein the reinforcing material comprises elongated segments; The mixture is used to form a sheet; Processing the sheet to align the elongated segments of the reinforcing material in parallel and form an anisotropic sheet; and To combine two or more anisotropic sheets together; The mixture comprises: 30wt% to 70wt% of rubber raw materials; 5 wt% to 30 wt% of reinforcing materials; and 5wt% to 45wt% of filler; The anisotropic sheet is incorporated into the high-efficiency belt as the wedge material. The parallel-aligned elongated segments are aligned transversely to the rotation direction of the high-efficiency belt; The high-efficiency belt has an anisotropic elastic modulus; Wherein, the ratio of the elastic modulus in the direction in which the elongated segments are aligned to the elastic modulus in the direction transverse to the direction in which the elongated segments are aligned is in the range of 1.1 to 5.0; and Wherein, the coefficient of friction of the high-efficiency belt is greater than or equal to 0.03 mm / N multiplied by the bending stiffness of the high-efficiency belt, and The thickness of the high-efficiency belt is 3.0 mm to 3.8 mm.

8. The method according to claim 7, wherein, The elongated segments of the reinforcing material comprise chopped fibers, and wherein processing the sheet to align the elongated segments of the reinforcing material in parallel and form an anisotropic sheet comprises calendering the sheet.

9. The method according to claim 7, wherein, Joining two or more anisotropic sheets together includes: placing two anisotropic sheets side by side, wherein the elongated segments of the reinforcing material are parallel to each other and aligned in a direction perpendicular to the direction in which the anisotropic sheets are placed side by side; and securing the two anisotropic sheets together.

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