Helical tooth belt with low compression ratio and design method thereof

Abstract

The invention discloses a low-compression-ratio helical tooth belt and a design method thereof, and relates to the technical field of conveying belts. According to the design method, a definition formula is obtained based on definition of the compression ratio, and due to the fact that the length variation of the helical tooth belt in the working state depends on factors such as material characteristics and tooth shape parameters of the helical tooth belt and tension in the transmission process, the design method for the compression ratio of the helical tooth belt further comprises the following steps that A, the elastic elongation of the helical tooth belt is calculated; b, calculating the length variation of the helical tooth belt due to tooth profile compression; c, calculating the length variation of the helical tooth belt caused by other factors; and D, further correcting, and calculating to obtain the compression ratio of the helical tooth belt. The method has the advantages that the compression ratio expression is deduced by the design method, scientific basis is provided for designers, the design process is more systematized and standardized, the number of experiments is reduced and the calculation process is simplified by applying the compression ratio expression, and the design efficiency and the manufacturing speed are remarkably improved.

Description

Technical Field

[0001] The invention relates to the technical field of conveyor belts, and in particular to a low-compression helical toothed belt and a design method thereof. Background Art

[0002] In the conventional transmission process of spur belts and gears, the belt mainly plays the role of transmitting power, while the gears are responsible for changing the speed and torque. In this process, the belt needs to have a certain tension to ensure good meshing with the gears, but its compression rate does not need to be considered. For the meshing transmission of helical belts and helical gears, since the tooth profiles of the helical belts and helical gears are both involute spiral surfaces, they can gradually enter and exit during meshing, thereby improving the smoothness of the transmission. For a tooth, there is a process of meshing from one end to the other end. The contact and extrusion between the helical belt and the helical gear will cause a certain deformation of the helical belt, so the influence of the compression rate needs to be considered.

[0003] For example, in the helical tooth matching of a car steering wheel, the compression rate of the helical tooth belt is a key parameter related to the transmission efficiency and performance of the helical tooth belt. The compression rate is defined as the ratio of the length change of the helical tooth belt under working conditions to its original length. It reflects the degree of deformation of the belt when it is subjected to force. The compression rate is affected by many complex factors, including the material, structure, working environment, operating conditions of the belt, and the specific design of the helical tooth matching.

[0004] In the helical belt transmission system, the interaction between the belt and the helical gear involves complex mechanical and tribological principles, which makes it particularly difficult to accurately calculate the compression rate of the helical belt. At present, most designers rely on a large number of experiments to test the compression rate of the helical belt. This method is not only time-consuming and labor-intensive, but the results of each experiment are only applicable to specific design requirements. When a new design is needed, the designer needs to repeat this tedious process, which greatly limits the efficiency of production and manufacturing.

[0005] Therefore, deriving a calculation formula for the compression rate of helical belts with a certain degree of universality is of great significance for improving production efficiency and reducing the workload of experimenters. Such a formula will enable designers to obtain accurate results through a relatively small number of experiments, thereby accelerating the design and optimization process of the helical belt transmission system. However, this field still lacks direct and specific mathematical expressions to accurately calculate the compression rate of helical belts, which is also an important direction of current research and technological development.

[0006] Based on this, the applicant proposed a low-compression helical belt and a design method thereof to solve the above technical problems. Summary of the invention

[0007] The invention aims at the deficiencies in the prior art and provides a low-compression helical toothed belt and a design method thereof.

[0008] The present invention is solved by the following technical solutions: A design method for a low compression ratio helical belt is based on the definition of compression ratio, which is the ratio of the length change of the helical belt under working condition to its original length. The definition formula is: , in, Indicates the compression rate of the helical toothed belt, L 0 represents the length of the helical toothed belt in the relaxed state. L w It indicates the length of the helical belt after it is subjected to the tension generated by the helical teeth. L w Depending on the material properties, tooth profile parameters and tension of the helical toothed belt during transmission, the design method of the compression rate of the helical toothed belt also includes the following steps: Step A: Considering the elastic elongation of the helical toothed belt, calculate the elastic elongation of the helical toothed belt by Hooke's law; Step B: Considering the tooth compression of the helical toothed belt, firstly, an empirical coefficient is calculated through a large number of experiments and fitting the experimental results, and then the length change of the helical toothed belt due to the tooth compression is calculated based on the empirical coefficient; Step C: Considering the influence of other factors, firstly calculate the correction coefficient through a large number of experiments and fitting the experimental results, and then calculate the length change of the helical toothed belt caused by other factors in combination with the correction coefficient; Step D: Integrate the results obtained in steps A to C to obtain the length change of the helical belt under working conditions, and further correct and calculate the compression rate of the helical belt based on the defined formula.

[0009] Preferably, in step A, the elastic elongation of the bevel toothed belt is considered, and according to Hooke's law, the relationship between the elongation and stress of the bevel toothed belt is expressed as: , By transforming the above formula, we can get: , in, represents stress, F Indicates the tension acting on the helical toothed belt during transmission. E represents the elastic modulus, A Indicates the cross-sectional area of ​​the helical toothed belt, Indicates the elastic elongation of the bevel toothed belt.

[0010] Preferably, in step B, the tooth compression of the helical toothed belt is considered, which is related to factors such as the tooth height, contact angle, and interaction between the helical toothed belt and the helical gear. Based on the complexity of the helical toothed belt, an empirical coefficient is introduced. Simplifying the problem, we get: , in, h represents the height of the tooth, It represents the contact angle between the helical belt and the helical gear. N Indicates the number of teeth of the helical belt in contact with the helical gear. Indicates the change in length of the helical toothed belt due to compression of the tooth profile.

[0011] Preferably, the empirical coefficient The value range is 0.1~10.

[0012] Preferably, based on the transmission characteristics of the helical toothed belt and practical applications, the empirical coefficient The optimal value range is 1 to 5.

[0013] Preferably, in step C, the influence of other factors such as temperature and wear of the bevel belt on the length of the bevel belt is considered, and based on the complexity of other factors, a correction coefficient is introduced. k Simplifying the problem, we get: ,

[0014] in, Indicates the length change of the helical toothed belt caused by other factors.

[0015] Preferably, the correction factor k The value range is 0.8~1.2.

[0016] Preferably, in step D, by comprehensively considering the above factors, the length change of the helical toothed belt in the working state can be obtained, and the compression rate can be obtained based on the length change: , The above , , Substituting the expression into and simplifying it, we get: , because , , After further correction, the final expression of the compression rate of the helical belt is obtained: , in, Indicates the tension correction factor, Indicates the tooth profile correction coefficient.

[0017] Preferably, the tension correction factor The value range is 1.1~1.8, and the tooth profile correction coefficient The value range is 0.5~5.

[0018] A low-compression helical toothed belt, whose compression rate conforms to the result calculated by the above-mentioned design method.

[0019] The beneficial effects of the present invention are: 1. Optimize the design and manufacturing process: This design method introduces a series of mathematical models and calculation formulas, such as elastic elongation, length change caused by tooth compression or other factors, and the final compression rate expression. These formulas provide a scientific basis for designers, making the design process more systematic and standardized. At the same time, by using the compression rate expression, the number of experiments can be reduced and the calculation process can be simplified, which significantly improves the design efficiency and manufacturing speed; 2. Enhanced adaptability and flexibility: Parameters such as the empirical coefficient and correction coefficient in the design method can be adjusted and optimized according to different application scenarios and requirements, thereby enhancing the adaptability and flexibility of the design method. This enables designers to quickly customize helical toothed belts that meet specific needs based on different working environments, operating conditions, and specific design requirements of helical tooth matching; 3. Reduce production costs and energy consumption: By optimizing the design of the helical toothed belt, unnecessary material waste and energy consumption are reduced. At the same time, due to the improvement of design efficiency and manufacturing speed, production costs and cycles are also reduced, bringing higher economic benefits to the enterprise; 4. Improve transmission efficiency and stability: By accurately calculating and designing the compression rate of the helical toothed belt, it is ensured that the belt can maintain a small deformation when subjected to force, thereby improving the efficiency and stability of the transmission. This is particularly important for fields that require high-precision transmission and stable performance, such as automotive steering wheels, automation equipment and precision machinery; 5. Promote technological progress and innovation: The proposal and implementation of this design method not only solves the problem of the difficulty in accurately calculating the compression rate in the helical belt transmission, but also provides strong support for technological progress and innovation in related fields. It promotes the continuous optimization and upgrading of the helical belt transmission system in design, manufacturing, testing, etc., and injects new vitality and impetus into the development of the industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be discussed below. Obviously, the technical solutions described in conjunction with the drawings are only some embodiments of the present invention. For ordinary technicians in this field, other embodiments and their drawings can be obtained based on the embodiments shown in these drawings without paying creative work.

[0021] Figure 1 It is a flow chart of the design method of the present invention.

[0022] Figure 2 It is a schematic diagram of the three-dimensional structure of the oblique toothed belt of the present invention. DETAILED DESCRIPTION

[0023] The technical solutions of various embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments described in the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] Example 1: Figure 1 As shown, a design method of a low compression ratio helical toothed belt of the present invention is based on the definition of compression ratio, and the ratio of the length change of the helical toothed belt in the working state to its original length, and the definition formula is obtained: , in, Indicates the compression rate of the helical toothed belt, L 0 represents the length of the helical toothed belt in the relaxed state. L w It indicates the length of the helical belt after it is subjected to the tension generated by the helical teeth. L w Depending on the material properties, tooth profile parameters and tension of the helical toothed belt during transmission, the design method of the compression rate of the helical toothed belt also includes the following steps: Step A: Considering the elastic elongation of the helical toothed belt, the elastic elongation of the helical toothed belt is calculated by Hooke's law. According to Hooke's law, the relationship between the elongation and stress of the helical toothed belt is expressed as: , By transforming the above formula, we can get: , in, represents stress, F Indicates the tension acting on the helical toothed belt during transmission. E represents the elastic modulus, AIndicates the cross-sectional area of ​​the helical toothed belt, Indicates the elastic elongation of the helical toothed belt; Step B: Considering the tooth compression of the helical toothed belt, firstly, the empirical coefficient is calculated through a large number of experiments and fitting the experimental results, and then the length change of the helical toothed belt due to the tooth compression is calculated based on the empirical coefficient. Considering the tooth compression of the helical toothed belt, which is related to factors such as the tooth height, contact angle, and the interaction between the helical toothed belt and the helical gear, based on the complexity of the helical toothed belt, the empirical coefficient is introduced Simplifying the problem, we get: , in, h represents the height of the tooth, It represents the contact angle between the helical belt and the helical gear. N Indicates the number of teeth of the helical belt in contact with the helical gear. Indicates the change in length of the helical toothed belt due to compression of the tooth profile.

[0025] The above The expression is a simplified formula obtained by fitting experimental data. The formula is also based on the assumption of linear relationship. Although in actual situations, the influence of various factors is complex and non-linear, in the process of simplifying the model, in order to facilitate understanding and application, and to express the influence of various factors on the results more concisely, it is assumed that the influence between various factors is linear. In order to make the results more accurate, the empirical coefficient is introduced. , and finally fitted, based on this formula, engineers can quickly use it to estimate the length change of the helical toothed belt due to tooth compression without performing complex mathematical calculations.

[0026] Empirical coefficient The value range of is 0.1~10. In this embodiment, based on the transmission characteristics of the helical toothed belt and the actual application, the empirical coefficient The optimal value range is 1~5. In practical applications, the empirical coefficient The value range of still needs to be determined through experiments or a large amount of industrial data within the industry; The above experiment controls the three factors of tooth height, contact angle between the helical belt and the helical gear, and number of teeth in contact between the helical belt and the helical gear, and fits the relationship between the length change of the helical belt due to tooth compression and these three factors.

[0027] Step C: Considering the influence of other factors, first calculate the correction coefficient through a large number of experiments and fitting the experimental results, and then calculate the length change of the helical belt caused by other factors based on the correction coefficient. Considering the influence of other factors such as temperature and helical belt wear on the length of the helical belt, based on the complexity of other factors, the correction coefficient is introducedk Simplifying the problem, we get: , in, Indicates the length change of the helical toothed belt caused by other factors.

[0028] The elastic elongation of the helical toothed belt is the basic deformation of the helical toothed belt when it is subjected to force. It is caused by the elastic properties of the helical toothed belt material and can be described by physical laws such as Hooke's law. Therefore, when analyzing the change in belt length, elastic elongation is an important basic quantity. During the operation of the helical toothed belt, it is also affected by other factors, resulting in additional deformation. This part of the deformation is related to the elastic elongation and a correction factor is introduced. k , the known elastic elongation can be used to estimate the length change of the helical toothed belt caused by other factors, without the need for detailed physical modeling and analysis of each additional influencing factor. This simplifies the model and facilitates calculation and application. When designing and analyzing helical toothed belt transmission systems, engineers can quickly use this formula to estimate the length change of the helical toothed belt caused by other factors.

[0029] Correction factor k The determination is also based on the fitting of experimental data, and the correction coefficient k The value range is 0.8~1.2. In practical applications, the correction coefficient k The value range of still needs to be determined by experiments according to specific circumstances or based on a large amount of industrial data in the industry to more accurately reflect the actual situation; Step D: Taking the above factors into consideration, the results obtained in Steps A to C are integrated to obtain the length change of the helical toothed belt in the working state. Based on the length change, the compression rate is obtained as follows: , The above , , Substituting the expression into and simplifying it, we get: , because , , After further correction, the final expression of the compression rate of the helical belt is obtained: , in, Indicates the tension correction factor, Indicates the tooth profile correction coefficient.

[0030] Because there is mutual influence between various factors, the tension correction coefficient and (1+ k ) are not equivalent, and They are not the same, the tension correction factor The value range is 1.1~1.8, and the tooth profile correction coefficient The value range of is 0.5~5. The range is determined based on experimental results, fitting discrete data points, and correcting them based on general engineering experience.

[0031] like Figure 2 As shown, a low-compression helical toothed belt has a compression ratio that conforms to the result calculated by the above-mentioned design method.

[0032] This low compression helical tooth belt can be used for the EPS electric power steering belt of the car steering wheel. It is a 5° helical tooth 2mm pitch synchronous belt with a diameter of 100mm, a width of 20mm, and a tooth height of 0.8mm. It is highly wear-resistant, oil-resistant, and temperature-resistant from -40℃ to 140℃, with better noise reduction effect. It can also be used for EPB electronic handbrake belts. It is a 2° helical tooth 3mm pitch synchronous belt with high wear resistance and temperature resistance from -40℃ to 140℃.

[0033] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered exemplary and non-restrictive from any point of view. The scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0034] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A design method for a low compression ratio helical toothed belt, characterized in that: Based on the definition of compression rate, the ratio of the length change of the helical toothed belt under working condition to its original length, the definition formula is obtained: ， in, Indicates the compression rate of the helical toothed belt, L 0 represents the length of the helical toothed belt in the relaxed state. L w It indicates the length of the helical belt after it is subjected to the tension generated by the helical teeth. L w Depending on the material properties, tooth profile parameters and tension factors of the helical toothed belt during transmission, the design method of the compression rate of the helical toothed belt also includes the following steps: Step A: Considering the elastic elongation of the helical toothed belt, calculate the elastic elongation of the helical toothed belt by Hooke's law; Step B: Considering the tooth compression of the helical toothed belt, calculate the length change of the helical toothed belt due to the tooth compression by combining the empirical coefficient; Step C: Consider the influence of other factors and calculate the length change of the helical toothed belt caused by other factors in combination with the correction coefficient; Step D: Integrate the results obtained in steps A to C to obtain the length change of the helical belt under working conditions, and further correct and calculate the compression rate of the helical belt based on the defined formula.

2. The design method of a low compression ratio helical toothed belt according to claim 1, characterized in that: In step A, the elastic elongation of the helical toothed belt is considered. According to Hooke's law, the relationship between the elongation and stress of the helical toothed belt is expressed as: ， By transforming the above formula, we can get: ， in, represents stress, F Indicates the tension acting on the helical toothed belt during transmission. E represents the elastic modulus, A Indicates the cross-sectional area of ​​the helical toothed belt, Indicates the elastic elongation of the bevel toothed belt.

3. The design method of a low compression ratio helical belt according to claim 2, characterized in that: In step B, the tooth compression of the helical toothed belt is considered, which is related to the tooth height, contact angle and the interaction between the helical toothed belt and the helical gear. Based on the complexity of the helical toothed belt, the empirical coefficient Simplifying the problem, we get: ， in, h represents the height of the tooth, It represents the contact angle between the helical belt and the helical gear. N Indicates the number of teeth of the helical belt in contact with the helical gear. Indicates the change in length of the helical toothed belt due to compression of the tooth profile.

4. The design method of a low compression ratio helical belt according to claim 3, characterized in that: Empirical coefficient The value range is 0.1~10.

5. The design method of a low compression ratio helical toothed belt according to claim 4, characterized in that: Based on the characteristics of helical belt transmission and practical applications, the empirical coefficient The optimal value range is 1 to 5.

6. The design method of a low compression ratio helical belt according to claim 3, characterized in that: In step C, the influence of other factors on the length of the helical belt is considered. Based on the complexity of other factors, a correction factor is introduced. k Simplifying the problem, we get: ， in, Indicates the length change of the helical toothed belt caused by other factors.

7. The design method of a low compression ratio helical belt according to claim 6, characterized in that: Correction factor k The value range is 0.8~1.

2.

8. The design method of a low compression ratio helical toothed belt according to claim 6, characterized in that: In step D, the length change of the helical toothed belt in the working state is obtained by integration, and based on the length change, the compression rate of the helical toothed belt is obtained as follows: ， Will , , Substituting the expression into and simplifying it, we get: ， because , , The mutual influence between them is further modified to obtain the final expression of the compression rate of the helical belt: ， in, Indicates the tension correction factor, Indicates the tooth profile correction coefficient.

9. The design method of a low compression ratio helical toothed belt according to claim 8, characterized in that: Tension correction factor The value range is 1.1~1.8, and the tooth profile correction coefficient The value range is 0.5~5.

10. A low compression ratio helical toothed belt, characterized in that: The compression ratio thereof conforms to the result calculated by the design method described in any one of claims 1 to 9.

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