Multi-layer reinforced belt

Abstract

A multilayer reinforced industrial belt is described, which generally includes a plurality of cords embedded within a main body of the belt and a reinforcing canvas layer embedded within the main body of the belt between the plurality of cords and the contact surface of the belt. In some embodiments, the cords are slightly off-parallel to the running direction of the belt, and first or second fibers of the woven reinforcing canvas layer are aligned parallel to the running direction of the belt or at an angle to the running direction of the belt. When the first or second fibers of the reinforcing canvas layer are angled with respect to the running direction, the angle is opposite to the angle of the cords with respect to the running direction.

Description

[Technical Field]

[0001] This application relates to industrial belts, and more particularly to multi-layer reinforced industrial belts. The multi-layer reinforced belts described herein have an embedded fabric reinforcement canvas layer and a plurality of cords, and the fabric reinforcement canvas layer and the cords are intentionally offset to provide various improvements, including improved tracking resistance of the belt. [Background technology]

[0002] 1, there is shown a conventionally known construction of an industrial belt 100. The belt 100 has a plurality of reinforcing cords 110 embedded in a main body 120 of the belt 100 and extending substantially parallel to the direction of travel of the belt 100 (the direction of travel of the belt is indicated by arrow 101). The belt 100 further includes a backing layer 140 on a back surface of the belt 100, as is well known in the art.

[0003] The belt shown in FIG. 1 further includes surface features formed on the contact surface side of the belt 100, which are teeth 130 oriented generally perpendicular to the direction of travel 101 and extending along the entire length of the belt 100. Thus, while the belt 100 shown in FIG. 1 is considered a toothed belt, it should be understood that the overall belt body configuration shown in FIG. 1 can be used with any other type of belt, including belts having different surface features on the contact surface of the belt. For example, the surface features may alternatively be one or more ribs oriented generally parallel to the direction of travel 101. The contact surface of the belt may be flat (i.e., without surface features). Other belt types that commonly use the belt body configuration shown in FIG. 1 include V-belts, micro-V-belts, timing belts, synchronous belts, friction belts, etc.

[0004] Figure 1A is a simplified top view of the belt 100 shown in Figure 1. The belt 100 has multiple cords 110 across the entire width of the belt 100, but for simplicity, Figure 1A shows only a single cord 110. Figure 1A illustrates that, generally speaking, the arrangement of the cords 110 embedded within the belt body 120 of the belt 100 is not perfectly parallel to the running direction 101 of the belt 100. Thus, the expression "substantially parallel" used in the previous paragraph means close to parallel, rather than actually parallel.

[0005] With respect to the orientation or alignment of the cords 110 embedded within the body portion 120 of the belt 100, the cords 110 are generally oriented at an angle A relative to the direction of travel 101. Angle A is referred to as the helical angle, walk angle, and / or rack angle because of the way the cords are typically wrapped around the belt body material during belt manufacture. While angle A cannot be too large, a particular value for angle A is generally not limited. In some embodiments, angle A is between 0° and 5°, although larger upper limits such as 10°, 15°, 20°, or 25° are also possible. Orienting the cords substantially parallel, but not perfectly parallel, to the direction of travel of the belt 100 can cause performance issues with the belt 100.

[0006] In one particular example, a cord that is slightly misaligned with the belt's direction of travel can cause the belt to shift laterally during use, as well as in the direction of travel. In some specific applications, for example, in personal transportation vehicles such as e-bikes, the vehicle frame is flexible and the sprockets move laterally, which causes greater forces to act on the sides of the belt. While frame flexibility is generally instantaneous (meaning the frame quickly returns to its normal, unflexed state, and belt tracking shortens accordingly), this can cause issues with belt loads.

[0007] Regardless of cord orientation, cords often create weak spots in belts when subjected to large loads. This weakness is due to the relatively small surface area provided by the cord as an adhesive area between the belt's composite and the cord. When large forces are applied, the belt tears at the interface between the cord and the composite, thereby damaging the belt.

[0008] Furthermore, while the cords serve as the primary means of improving the strength and load capacity of the belt, the cord material is an expensive aspect of the belt, and therefore the presence of the cords in the belt increases the overall cost of the belt.

[0009] To accommodate the off-axis reinforcing cords, additional cords are required, as well as the use of high performance material systems at higher manufacturing costs.

[0010] For at least these reasons, a need exists for improved industrial belts that do not suffer from the problems discussed above. Summary of the Invention

[0011] This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary and the foregoing Background are not intended to identify key features or essential features of the claimed subject matter. Moreover, this Summary is not intended to be used as an aid in determining the scope of the claimed subject matter.

[0012] In some embodiments, a multi-layer reinforced belt is disclosed, the multi-layer reinforced belt generally including a main body extending from a back surface to a contact surface of the multi-layer reinforced belt, a plurality of cords embedded within the main body, the plurality of cords having longitudinal axes substantially parallel to the direction of travel of the belt, and a reinforcing canvas layer embedded within the main body between the plurality of cords and the contact surface of the belt. The reinforcing canvas layer may be in the form of a weave of first fibers and second fibers, the first fibers being substantially perpendicular to the second fibers. The orientation of the reinforcing canvas layer within the main body is such that neither the first fibers nor the second fibers are aligned parallel to the longitudinal axes of the plurality of cords.

[0013] These and other aspects of the technology described herein will become apparent after consideration of the detailed description and drawings herein. It should be understood, however, that the scope of the claimed subject matter is determined by the claims, and not by whether they address some or all of the problems described in the Background of the Invention or include any features or aspects described in the Abstract. [Brief explanation of the drawings]

[0014] Non-limiting, exemplary embodiments of the disclosed technology, including preferred embodiments, are described with reference to the following figures, in which like reference numerals refer to like elements in different figures unless otherwise specified:

[0015] [Figure 1] 1 is a perspective view of a toothed belt showing cross sections in the longitudinal and width directions of the belt. FIG.

[0016] [Figure 1A] 2 is a simplified schematic top view of the toothed belt shown in FIG. 1.

[0017] [Figure 2] 1 is a perspective view of a toothed belt showing longitudinal and transverse cross sections of the belt, the toothed belt being constructed in accordance with various embodiments described herein.

[0018] [Figure 2A] FIG. 3 is a simplified schematic side view of the toothed belt shown in FIG. 2.

[0019] [Figure 3A] 1 is a simplified schematic top view of a multi-layer reinforced belt constructed in accordance with various embodiments described herein.

[0020] [Figure 3B] 1 is a simplified schematic top view of a multi-layer reinforced belt constructed in accordance with various embodiments described herein. DETAILED DESCRIPTION OF THE INVENTION

[0021] The embodiments are described in more detail with reference to the accompanying drawings, which form a part of this specification and which show, by way of example, certain exemplary embodiments. These embodiments are disclosed in sufficient detail to enable those skilled in the art to practice the invention. However, embodiments may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Accordingly, the following detailed description is not to be taken in a limiting sense.

[0022] 2, a belt 200 similar in structure to the belt 100 shown in FIG. 1 includes a plurality of cords 110 aligned substantially parallel to the running direction 101, a main body 120 in which the plurality of cords 110 are embedded, optional surface features 130 formed on the contact surface of the belt 200, and a back layer 140 on the back surface of the belt 200. The belt 200 shown in FIG. 2 also includes a reinforcing canvas layer 210 embedded within the main body 120 of the belt 200, the reinforcing canvas layer 210 being positioned between the plurality of cords 110 and the contact surface of the belt 200. In the case of the particular belt configuration shown in FIG. 2, in which the belt 200 includes teeth 130, the reinforcing canvas layer 210 is positioned between the plurality of cords 110 and the surface features / teeth 130.

[0023] In some embodiments, the canvas layer 210 generally has a woven structure comprising an interweaving of first fibers and second fibers, with the first fibers aligned generally perpendicular to the second fibers. The canvas layer may have multiple layers of this woven structure to form a stronger, thicker canvas layer 210. The particular material of the canvas 210 is generally not limited. In some embodiments, the material of the canvas layer 210 is an interlocked yarn twist (ITY) fiber. Other suitable materials for the canvas layer 210 include, but are not limited to, polyester, polyamide, nylon, polypropylene, polyethylene, ceramic fiber, carbon fiber, and metal fiber.

[0024] 2, the canvas layer 210 is shown spaced apart from the layer of cords 110. In such embodiments, the material used for the main body 120 of the belt 200 is located between the canvas layer 210 and the cords 110. In other embodiments, the canvas layer 210 is placed on or directly over the cords 110, such that there is direct contact between the cords 110 and the canvas layer 210. In either embodiment, the woven nature of the canvas layer 210 creates gaps within the canvas layer 210. In some embodiments, the material for the main body 120 extends through the canvas layer 210 by flowing through these gaps during the manufacture of the belt 200. In some embodiments where the canvas layer 210 is positioned closely or directly against the cords 110, the canvas layer 210 effectively acts to increase the surface area of ​​the cords 110, thereby improving adhesion between the cords 110 and the material of the body portion 120 of the belt 200 as the material of the body portion 120 extends through the canvas layer 210 toward the cords 110. In embodiments where these features improve adhesion, this may improve the overall load capacity of the belt 200.

[0025] The size of the reinforcing canvas layer 210 is selected so that the reinforcing canvas layer 210 extends across the entire width or nearly the entire width of the belt 200, and so that the reinforcing canvas layer 210 extends across the entire length of the belt 200. The thickness of the canvas layer 210 is generally not limited, but in some embodiments, the thickness of the canvas layer 210 is generally within the range of about 0.3 to about 2.8 mm.

[0026] Referring to Figures 3A and 3B, different canvas layer arrangements are shown for use in various embodiments described herein. While it should be understood that in a typical configuration, multiple cords 110 are disposed across the width of the belt 300, a single cord 110 is shown in Figure 3A for simplicity's sake. Figure 3A further illustrates that the cord 110 is substantially parallel to the running direction 101. That is, rather than being parallel to the running direction 101, the cord 110 is angled relative to the running direction, ranging from 0° to, for example, approximately 5°. Figure 3A shows a canvas layer 310 disposed between the multiple cords 110 and the contact surface of the belt 300. Again, for simplicity's sake, only a portion of the canvas layer 310 is shown. In a typical configuration, the canvas layer 310 has the same width and length dimensions as the belt 300, extending across both sides of the belt 300 and the entire length of the belt 310.

[0027] As described above, the canvas layer 310 includes first fibers 310a and second fibers 310b woven together to form a weave of the fibrous material. The first fibers 310a are generally perpendicular to the second fibers 310b. In the embodiment shown in FIG. 3A, the canvas layer 310 is positioned within the belt 300 so that the first fibers 310a are aligned parallel to the travel direction 101. Importantly, the canvas layer 310 is positioned so that the first fibers 310a are not parallel to the cords 110. As described in more detail elsewhere in this disclosure, the fibers of the canvas layer 310 that are not parallel to the cords 110 help to reduce lateral forces caused by the angle of the cords 110 relative to the travel direction 101.

[0028] 3B illustrates another configuration in which the canvas layer 310 is positioned within the belt such that the first fibers 310a are not parallel to either the machine direction 101 or the cords 110. Instead, in this configuration, the angle between the first fibers 310a and the machine direction 101 (labeled angle B in FIG. 3B) is less than 0° relative to the angle between the machine direction 101 and the cords 110. In other words, when the cords 110 angle clockwise relative to the machine direction 101, the first fibers 310a angle counterclockwise relative to the machine direction 101. In other words, when all angles are measured in a common direction relative to the machine direction 101 (e.g., clockwise), the angle of the first fibers ranges from, for example, 340° to 360°. In some embodiments, angle B ranges from 0° to about −5°, but may also be, for example, −10°, −15°, −20°, −25°, etc. Regardless of the particular angle at which the first fibers 310a of the canvas layer 310 deviate from the direction of travel 101 in a direction opposite to the angle between the cords 110 and the travel direction, the effect is similar to that described above with respect to the embodiment shown in Figure 3A: the orientation of the first fibers 310a of the canvas layer 310 helps to counteract or offset the lateral force caused by the angle of the cords 110 within the belt 300 relative to travel 101.

[0029] Referring again to FIG. 2A , the material of the main portion 120 of the belt 200 is not generally limited and includes all materials suitable as composite materials for industrial belts. In some embodiments, the material of the main portion 120 is polyurethane. A single type of polyurethane can be used throughout the main portion 120, for example, in the region between the back surface and the cords 110, the region between the cords 110 and the reinforcing canvas layer 210, and from the canvas layer 210 to the contact surface of the belt 200. In embodiments where the contact surface includes surface features (such as the teeth 130 shown in FIG. 2A ), a single polyurethane is used in the surface features. In other embodiments, two or more materials (e.g., two or more different types of polyurethane) are used in different portions of the main portion 120. For example, the region between the back surface and the cords 110 of the belt 200 (labeled 120a in FIG. 2A ) is made from a first composite material, such as a first polyurethane having a first modulus. The region between the cords 110 and the canvas layer 210 (labeled 120b in FIG. 2A) is made from a second composite material, such as a second polyurethane, having a second modulus different from the first modulus of the first polyurethane material used in the region between the backside and the cords 110. The region from the canvas layer 210 to the contact surface (including the tooth-like surface features, if included) (labeled 120c in FIG. 2A) is made from a third composite material, such as a third polyurethane, having a third modulus different from the first and second moduli. Each of the regions 120a, 120b, and 120c may also be made from multiple layers of different composite materials. For example, the region 120a includes a first layer of polyurethane having a first modulus and a second layer of polyurethane having a second modulus. In another example, the inner portion of the tooth 130 is made from a third polyurethane having a third modulus, and the outer portion of the tooth is made from a fourth layer of polyurethane having a fourth modulus.

[0030] When multiple types of composite materials (e.g., different types of polyurethane) are used in various portions of the body portion 120, the different types of materials used can be selected to have different other properties. For example, each type of material used can have different adhesive or curing properties. In some embodiments, each material used in different portions of the body portion can have a modulus, adhesive properties, and curing properties, at least one of which is different from the corresponding properties of the other materials used. For example, when three different materials are used in three portions of the body portion, the first, second, and third materials can each have a different modulus but similar adhesive and curing properties. In another example, when three different materials are used in three portions of the body portion, the first, second, and third materials can each have a different modulus, different adhesive properties, and different curing properties.

[0031] In embodiments where multiple composite materials are used and region 120b is provided between the cords 110 and the canvas layer 210 (i.e., a configuration where the canvas layer 120 is not directly against the cords 110), the belt 200 is designed so that the composite material in region 120c extends through the canvas layer 210 toward the cords 110, or the composite material in region 120b extends through the canvas layer 210 toward the contact surface, or a combination of both.

[0032] As discussed above with respect to the description of the belt configuration shown in Figure 1, embodiments of multi-layer reinforced belts having a reinforcing canvas layer disposed between the cords and the contact surface can be used in all types of industrial belts, including those with and without surface features on the contact surface. Thus, the belt embodiments described herein include V-belts, micro-V-belts, timing belts, flat belts, ribbed belts, toothed belts, synchronous belts, and friction belts, as well as other types of industrial belts.

[0033] In the embodiments described herein, the belt is described as including a plurality of cords embedded in the body. For example, as shown in FIG. 2, the cords are disposed across the width of the belt and are closely spaced. In some embodiments, each cord contacts adjacent cords, providing a high density of cord material within the belt. In some embodiments, the presence of a canvas layer in the belts described herein can improve the load capacity of the belt and allow for less cord material to be used in the belt. Less cord material is achieved by spacing the cords apart, which means a lower cord density within the belt. Cords are typically an expensive component of a belt, and using fewer cords within a belt is a cost-saving measure that reduces the overall cost of the belt. The cost of the canvas layer material is relatively inexpensive, so adding a canvas layer to a belt does not offset the savings realized by using less cord material.

[0034] The method for manufacturing the belts described herein generally follows a known slab manufacturing process using a mold. For example, the manufacturing process may involve depositing, in order, the following materials into the mold: a surface layer; a composite material (formed into surface features such as teeth and ribs); a reinforcing canvas layer (positioned to ensure the desired fiber orientation of the reinforcing material relative to the belt's running direction); any composite material that does not contact the canvas layer with the cords; cord material (material already wrapped and processed); the composite material; and an optional backing layer. Once all materials are deposited in the mold, a heat curing process is used to stretch the surface layer and flow the composite material to form the surface features based on the mold shape, with the composite material flowing over or under the canvas layer. The molded belt is then removed from the mold and subjected to any necessary post-processing, such as grinding, branding, or singulation.

[0035] The incorporation of the canvas layer in the belts described herein provides a variety of benefits, some of which have been previously described. In a first example, it acts as a stabilizer that counteracts all or some of the lateral forces acting on the belt. In instances where a non-parallel cord arrangement causes lateral belt movement, the presence and placement of the canvas layer described herein eliminates this issue, allowing the belt to move only in the direction of travel. The presence and placement of the canvas layer can also counteract or smooth other chronic or temporary lateral forces that act on the belt, resulting in lateral forces at various angular positions, such as when the frame of the vehicle in which the belt is being used (e.g., on an e-bike) bends and moves the sprockets.

[0036] The multidirectionality of the canvas layer also helps distribute the load carried by the belt in multiple directions, rather than just one, as occurs when only cords are present in the belt. When the fibers are oriented so that the first fiber is parallel to the running direction, the second fiber distributes the load laterally. When the first fiber is oriented at an angle to the running direction, the first and second fibers can distribute the load in directions other than the running direction. Because the canvas layer distributes the load in multiple directions, this can increase the overall load capacity of the belt.

[0037] Considering the improved load distribution and load capacity provided to a belt when a canvas layer is incorporated as described herein, the belt can provide an equivalent load capacity using less cord material. Because the cost of cord is generally high relative to the cost of the canvas layer material, the incorporation of a canvas layer and elimination of cord material is a net reduction in belt cost and therefore reduces belt manufacturing costs.

[0038] Additionally, the presence of the canvas layer increases the surface area of ​​the cords, thereby improving the adhesion between the cords and the composite material used in the body of the belt. This strengthens the belt and allows the belt to support a greater load before the belt separates and the interface between the cords and the composite material begins to delaminate. Thus, the presence of the canvas layer and the concomitant improvement in adhesion within the belt ultimately allows the belt to support a greater load.

[0039] From the foregoing it will be appreciated that, although specific embodiments of the invention have been described herein for purposes of illustration, various modifications can be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited except as by the appended claims.

[0040] Although the present technology has been described in language specific to structure and materials, it is to be understood that the invention defined in the appended claims is not limited to the particular structure and materials described. Rather, specific features are described as forms of implementing the claimed invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention resides in the appended claims.

[0041] Unless otherwise indicated, all numerical values ​​or expressions used in this specification (except in the claims), such as those indicating sizes, physical properties, and the like, are understood to be modified in all instances by the term "about." At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the claims, each numerical parameter set forth in the specification or claims that is modified by the term "about" should be construed, at the very least, in light of the number of significant digits recited and by applying rounding techniques. Furthermore, all ranges recited herein should be understood to encompass and provide support for claims reciting all subranges or individual numerical values ​​contained therein. For example, a range recited as 1 to 10 should be considered to encompass and provide support for claims reciting all subranges or individual numerical values ​​between and / or including the minimum value of 1 and the maximum value of 10. That is, all subranges beginning at or above 1 and ending at or below 10 (e.g., 5.5 to 10, 2.34 to 3.56, etc.) or 1 to 10 (e.g., 3, 5.8, 9.9994, etc.).

Claims

1. 1. A multi-layer reinforced belt having a back surface and a contact surface opposite the back surface, a main body portion extending from the rear surface to the contact surface; a plurality of cords embedded within the body portion, the plurality of cords having longitudinal axes oriented substantially parallel to the direction of travel of the belt; a reinforcing canvas layer embedded in the main body between the plurality of cords and the contact surface of the belt, the reinforcing canvas layer having a weave of first fibers and second fibers, the first fibers being substantially perpendicular to the second fibers; The orientation of the reinforcing canvas layer within the main body portion is such that neither the first fibers nor the second fibers are aligned parallel to the longitudinal axes of the plurality of cords. Multi-layer reinforced belt.

2. 2. The multi-layer reinforced belt of claim 1, wherein the angle between the longitudinal axes of the plurality of cords and the direction of travel of the belt is from 0° to 5°.

3. 2. The multi-layer reinforced belt of claim 1, wherein each of said plurality of cords contacts an adjacent cord.

4. 2. The multi-layer reinforced belt of claim 1, wherein each of said plurality of cords is spaced apart from adjacent cords.

5. 2. The multi-layer reinforced belt of claim 1, wherein said first fibers or said second fibers of said multi-layer reinforced belt are aligned parallel to said direction of travel of said belt.

6. 2. The multi-layer reinforced belt of claim 1, wherein the angle formed between the running direction of the belt and either the first fibers or the second fibers of the multi-layer reinforced belt is from -5° to less than 0°.

7. 10. The multi-layer reinforced belt of claim 1, wherein said material of said reinforcing canvas layer comprises interlock twisted yarn (ITY) fibers.

8. 2. The multi-layer reinforced belt according to claim 1, wherein said material of said reinforcing canvas layer is selected from one or more of polyester, polyaramid, nylon, polypropylene, polyethylene, ceramic fiber, carbon fiber, and metal fiber.

9. 2. The multi-layer reinforced belt of claim 1, wherein said reinforcing canvas layer contacts said plurality of cords.

10. 10. The multi-layer reinforced belt of claim 1, wherein said body portion comprises two or more layers of different composite materials.

11. 2. The multi-layer reinforced belt of claim 1, wherein said body portion comprises at least a first layer of a first composite material and a second layer of a second composite material.

12. 12. The multi-layer reinforced belt of claim 11, wherein said first composite material is a polyurethane having a first modulus and said second composite material is a second polyurethane having a second modulus different from the first modulus.

13. 2. The multi-layer reinforced belt of claim 1, wherein said material of said body portion extends through said reinforcing canvas layer.

14. 10. The multi-layer reinforced belt of claim 1, wherein a plurality of surface features are formed on said contact surface.

15. 15. The multi-layer reinforced belt of claim 14, wherein said surface features are teeth oriented generally perpendicular to said direction of travel of said belt.

16. 15. The multi-layer reinforced belt of claim 14, wherein said surface features are ribs oriented generally parallel to said direction of travel of said belt.

17. 2. The multi-layer reinforced belt of claim 1, wherein said contact surface is substantially flat.

18. 10. The multi-layer reinforced belt of claim 1, wherein the multi-layer reinforced belt is a ribbed belt, a timing belt, a synchronous belt, a V-belt, a micro V-belt, a toothed belt, a friction belt, or a flat belt.

Images