A helical belt with a low compression ratio and its design method

Abstract

The present invention discloses a low compression ratio helical belt and its design method, which relates to the technical field of conveyor belts. Based on the definition of the compression ratio, a definition formula is obtained. Since the length change of the helical belt in the working state depends on factors such as the material properties of the helical belt, tooth profile parameters, and tension during the transmission process, the design method of the compression ratio of the helical belt further includes the following steps: Step A: Calculate the elastic elongation of the helical belt; Step B: Calculate the length change of the helical belt due to tooth profile compression; Step C: Calculate the length change of the helical belt caused by other factors; Step D: Calculate the compression ratio of the helical belt after further correction. The beneficial effect of the present invention is that this design method derives the compression ratio expression, provides a scientific basis for designers, makes the design process more systematic and standardized, reduces the number of experiments and simplifies the calculation process by using this compression ratio expression, and significantly improves the design efficiency and manufacturing speed.

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 present invention aims at the deficiencies in the prior art and provides a low-compression-ratio helical belt and its design method.

[0008] The present invention is solved by the following technical solutions:

[0009] A design method for a low-compression-ratio helical belt. Based on the definition of the compression ratio, which is the ratio of the length change of the helical belt in the working state to its original length, the definition formula is obtained:

[0010] ,

[0011] where, represents the compression ratio of the helical belt, L 0 represents the length of the helical belt in the relaxed state, L w represents the length of the helical belt after being subjected to the tension generated by the helical engagement. Since L w depends on factors such as the material properties of the helical belt, the tooth profile parameters, and the tension during the transmission process, the design method for the compression ratio of the helical belt further includes the following steps:

[0012] Step A: Considering the elastic elongation of the helical belt, calculate the elastic elongation of the helical belt through Hooke's law;

[0013] Step B: Considering the tooth profile compression of the helical belt, first calculate the empirical coefficient through a large number of experiments and fitting the experimental results, and then calculate the length change of the helical belt due to tooth profile compression in combination with this empirical coefficient;

[0014] 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 in combination with this correction coefficient;

[0015] Step D: Integrate the results obtained in Steps A to C to obtain the length change of the helical belt in the working state, and based on the definition formula, further correct and calculate to obtain the compression ratio of the helical belt.

[0016] Preferably, in Step A, considering the elastic elongation of the helical belt, according to Hooke's law, the relationship between the elongation and stress of the helical belt is expressed as:

[0017] ,

[0018] From the deformation of the above formula, it can be obtained:

[0019] ,

[0020] where, represents the stress, FDenotes the tension acting on the helical belt during the transmission process. E Denotes the elastic modulus. A Denotes the cross-sectional area of the helical belt. Denotes the elastic elongation of the helical belt.

[0021] Preferably, in step B, considering the tooth profile compression of the helical belt, which is related to factors such as the height of the teeth, the contact angle, and the interaction between the helical belt and the helical gear, based on the complexity of the helical belt, by introducing an empirical coefficient to simplify the problem, we get:

[0022] ,

[0023] where h Denotes the height of the teeth. Denotes the contact angle between the helical belt and the helical gear. N Denotes the number of teeth in contact between the helical belt and the helical gear. Denotes the change in length of the helical belt due to tooth profile compression.

[0024] Preferably, the value range of the empirical coefficient is 0.1 - 10.

[0025] Preferably, based on the transmission characteristics of the helical belt and actual applications, the more optimal value range of the empirical coefficient is 1 - 5.

[0026] Preferably, in step C, considering the influence of other factors such as temperature and wear of the helical belt on the length of the helical belt, based on the complexity of other factors, by introducing a correction coefficient k to simplify the problem, we get:

[0027] ,

[0028] where Denotes the change in length of the helical belt caused by other factors.

[0029] Preferably, the value range of the correction coefficient k is 0.8 - 1.2.

[0030] Preferably, in step D, by comprehensively considering the above factors, the change in length of the helical belt in the working state can be obtained. Based on this change in length, the compression ratio is:

[0031] ,

[0032] Substitute the above , , expressions and simplify to get:

[0033] ,

[0034] Due to , , mutual influence among them, the final expression of the compression ratio of the helical belt is obtained after further correction:

[0035] ,

[0036] wherein, represents the tension correction coefficient, represents the tooth profile correction coefficient.

[0037] Preferably, the value range of the tension correction coefficient is 1.1 to 1.8, and the value range of the tooth profile correction coefficient is 0.5 to 5.

[0038] A helical belt with a low compression ratio, the compression ratio of which conforms to the result calculated by the above design method.

[0039] The beneficial effects of the present invention are as follows:

[0040] 1. Optimize the design and manufacturing process: The design method introduces a series of mathematical models and calculation formulas, such as the elastic elongation, the length change caused by tooth profile compression or other factors, and the final compression ratio expression, etc. These formulas provide a scientific basis for designers, making the design process more systematic and standardized. At the same time, by using the compression ratio expression, the number of experiments can be reduced and the calculation process can be simplified, significantly improving the design efficiency and manufacturing speed;

[0041] 2. Enhance adaptability and flexibility: The 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 belts that meet specific requirements according to different working environments, operating conditions, and specific design requirements of helical tooth mating;

[0042] 3. Reduce production costs and energy consumption: By optimizing the design of the helical belt, unnecessary material waste and energy consumption are reduced. At the same time, due to the improvement of design efficiency and manufacturing speed, the production cost and cycle are also reduced, bringing higher economic benefits to the enterprise;

[0043] 4. Improve transmission efficiency and stability: By precisely calculating and designing the compression ratio of the helical belt, it is ensured that the belt can maintain a small deformation when stressed, thereby improving the transmission efficiency and stability. This is of particular significance for fields that require high-precision transmission and stable performance, such as automotive steering wheels, automation equipment, and precision machinery, etc.

[0044] 5. Promote technological progress and innovation: The proposal and implementation of this design method not only solve the problem of difficult accurate calculation of the compression ratio in helical belt transmission, but also provide strong support for technological progress and innovation in related fields. It promotes the continuous optimization and upgrading of helical belt transmission systems in aspects such as design, manufacturing, and testing, injecting new vitality and impetus into the development of the industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will discuss the drawings required for description in the embodiments or the prior art. Obviously, the technical solutions described in conjunction with the drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other embodiments and their drawings can be obtained based on these embodiments shown in the drawings.

[0046] Figure 1 is the flowchart of the design method of the present invention.

[0047] Figure 2 is the three-dimensional structure schematic diagram of the helical belt of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0048] The following will clearly and completely describe the technical solutions of each embodiment of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments. Based on the embodiments described in the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts are within the scope protected by the present invention.

[0049] Embodiment 1: As Figure 1 shown, a design method for a helical belt with a low compression ratio of the present invention, based on the definition of the compression ratio, which is the ratio of the length change of the helical belt in the working state to its original length, obtains the definition formula:

[0050] ,

[0051] wherein, represents the compression ratio of the helical belt, L 0 represents the length of the helical belt in the relaxed state, L w represents the length of the helical belt after being subjected to the tension generated by the helical engagement. SinceL w Depending on factors such as the material properties of the helical belt, tooth profile parameters, and tension during transmission, the design method of the compression ratio of the helical belt also includes the following steps:

[0052] Step A: Considering the elastic elongation of the helical belt, calculate the elastic elongation of the helical belt through Hooke's law. According to Hooke's law, the relationship between the elongation and stress of the helical belt is expressed as:

[0053] ,

[0054] By transforming the above formula, we can obtain:

[0055] ,

[0056] where, represents stress, F represents the tension acting on the helical belt during transmission, E represents the elastic modulus, A represents the cross-sectional area of the helical belt, represents the elastic elongation of the helical belt;

[0057] Step B: Considering the tooth profile compression of the helical belt, first calculate the empirical coefficient through a large number of experiments and fitting the experimental results, and then calculate the length change of the helical belt due to tooth profile compression in combination with this empirical coefficient. Considering the tooth profile compression of the helical belt, it is related to factors such as the height of the teeth, the contact angle, and the interaction between the helical belt and the helical gear. Due to the complexity of the helical belt, by introducing the empirical coefficient to simplify the problem, we get:

[0058] ,

[0059] where, h represents the height of the teeth, represents the contact angle between the helical belt and the helical gear, N represents the number of teeth in contact between the helical belt and the helical gear, represents the length change of the helical belt due to tooth profile compression.

[0060] The above expression is a simplified formula obtained by fitting experimental data. The derivation of this formula is also based on the assumption of a linear relationship. Although in actual situations, the influence of each factor is complex and not linear, in the process of simplifying the model, in order to facilitate understanding and application, and to more concisely express the influence of each factor on the result, it is assumed that the influence between each factor is linear. In order to make the result more accurate, the empirical coefficient , finally, through fitting, it is obtained that based on this formula, engineers can quickly use it to estimate the length change of the helical belt due to tooth profile compression without performing complex mathematical operations.

[0061] Empirical coefficient The value range of is 0.1 - 10. In this embodiment, based on the transmission characteristics of the helical belt and actual applications, the value range of the empirical coefficient is more preferably 1 - 5. In actual applications, the value range of the empirical coefficient still needs to be determined through experiments or a large amount of industrial data in the industry;

[0062] The above experiments are to control variables for three factors: the height of the teeth, the contact angle between the helical belt and the helical gear, and the number of teeth in contact between the helical belt and the helical gear, and fit the relationship between the length change of the helical belt due to tooth profile compression and these three factors.

[0063] 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 combine this correction coefficient to calculate the length change of the helical belt caused by other factors. Considering the influence of other factors such as temperature and wear of the helical belt on the length of the helical belt, due to the complexity of other factors, by introducing the correction coefficient k to simplify the problem, we get:

[0064] ,

[0065] where, represents the length change of the helical belt caused by other factors.

[0066] The elastic elongation of the helical belt is the basic deformation that occurs when the helical belt is stressed. It is caused by the elastic properties of the helical belt material and can be described by physical laws such as Hooke's law. Therefore, when analyzing the belt length change, the elastic elongation is an important basic quantity. During the operation of the helical belt, it is also affected by other factors, resulting in additional deformations. By relating this part of the deformation to the elastic elongation and introducing the correction coefficient k , it is possible to estimate the length change of the helical belt caused by other factors using the known elastic elongation amount, without the need to perform detailed physical modeling and analysis for each additional influencing factor, simplifying the model and facilitating calculation and application. When designing and analyzing the helical belt drive system, engineers can quickly use this formula to estimate the length change of the helical belt caused by other factors.

[0067] Correction coefficient k is also determined based on the fitting of experimental data. The value range of the correction coefficient k is 0.8 - 1.2. In actual applications, the correction coefficientk The value range still needs to be determined through experiments according to specific circumstances or based on a large amount of industrial data in the industry to more accurately reflect the actual situation;

[0068] Step D: Considering the above factors comprehensively, integrate the results obtained in Steps A to C to obtain the length change of the helical belt in the working state. Based on this length change, the compression ratio is obtained as:

[0069] ,

[0070] Substitute the above , , expressions and simplify to obtain:

[0071] ,

[0072] Since , , influence each other, after further correction, the final expression of the compression ratio of the helical belt is obtained:

[0073] ,

[0074] where represents the tension correction coefficient, represents the tooth profile correction coefficient.

[0075] Because there are mutual influences among various factors, the tension correction coefficient is not equal to (1 + k ), is not equal to either. The value range of the tension correction coefficient is 1.1 to 1.8, and the value range of the tooth profile correction coefficient is 0.5 to 5. The determination of this range is based on experimental results, fitting discrete data points, and correcting based on general engineering experience.

[0076] As Figure 2 shown, a low-compression-ratio helical belt has a compression ratio that conforms to the result calculated by the above design method.

[0077] This low-compression-ratio helical belt can be used for the EPS electric power steering belt of an automotive steering wheel. It is a 5° helical 2mm pitch synchronous belt with a diameter of 100mm, a width of 20mm, a tooth height of 0.8mm, high wear resistance, oil resistance, and temperature resistance from -40°C to 140°C, and has better noise reduction effect; it can also be used for the EPB electronic parking brake belt, which is a 2° helical 3mm pitch synchronous belt with high wear resistance and temperature resistance from -40°C to 140°C.

[0078] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above-described exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description, and thus all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be embraced within the present invention. Any reference signs in the claims should not be construed as limiting the claims involved.

[0079] In addition, it should be understood that although this specification is described according to embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments 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 toothed 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, 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, A Indicates the cross-sectional area of ​​the helical toothed belt, Indicates the elastic elongation of the helical toothed belt; Step B: Consider the tooth compression of the helical belt and calculate the length change of the helical belt due to tooth compression by combining empirical coefficients. The tooth compression of the helical belt is related to the tooth height, contact angle and the interaction between the helical belt and the helical gear. Based on the complexity of the helical 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 length change of the helical toothed belt due to tooth compression; Step C: Consider the influence of other factors and calculate the length change of the helical belt caused by other factors in combination with the correction coefficient. Based on the complexity of other factors, the correction coefficient is introduced k Simplifying the problem, we get: ， in, Indicates the length change of the helical toothed belt caused by other factors; Step D: Integrate the results obtained in step A to step C to obtain the length change of the helical toothed belt in the working state. 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.

2. The design method of a low compression ratio helical toothed belt according to claim 1, characterized in that: Empirical coefficient The value range is 0.1~10.

3. The design method of a low compression ratio helical toothed belt according to claim 2, 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.

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

2.

5. The design method of a low compression ratio helical belt according to claim 1, 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.

6. 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 5.

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