Model selection method of rubber covered roller

Abstract

The invention discloses a model selection method of a rubber-coated roller. The method comprises the following steps: firstly, creating a rubber-coated roller design calculation model: calculating a load G according to a grounding included angle, a grounding area, a grounding specific pressure and a safety coefficient; inputting a group of rubber covered roller parameters into the calculation model according to the use condition and the design size range of the rubber covered roller; the rated maximum static load of the rubber-coated roller is calculated and output through the calculation model; calculating a rated maximum dynamic load according to the maximum static load and the load rate; when the rated maximum static load, the rated maximum dynamic load and the single-wheel bearing capacity are decreased progressively, it is indicated that parameters of the selected rubber coating wheel meet the requirements, and design of the rubber coating roller is completed; and if the requirements are not met, re-inputting the parameters of the rubber-coated roller. According to the method, the rubber-coated roller can be selected quickly and accurately, and the service life of the rubber-coated roller is greatly prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of roller wheels, and particularly to a method for selecting a rubber-coated roller wheel. Background Art

[0002] Rubber-coated roller wheels are widely used in many fields such as logistics warehousing, industrial automation, rail transit, and construction sites.

[0003] In the field of logistics warehousing, rubber-coated roller wheels are often installed on equipment such as automated guided vehicles, stackers, and shuttle cars to efficiently move goods in the warehouse. Their high wear resistance and load-bearing capacity enable these devices to maintain stable performance during long-term and high-intensity operations.

[0004] During the selection process of rubber-coated roller wheels, preliminary judgments are made based on the usage conditions of the rubber-coated roller wheels. Then, through experience, a rubber-coated roller wheel that is considered suitable is first selected, or a relatively suitable rubber-coated roller wheel is matched from the existing product library. However, the selection of the above two methods is mainly based on experience, and the actual use effect still needs to be further tested. Especially for rubber-coated roller wheels that need to be redesigned with new dimensions, the new dimensions will surely form different load-bearing capacities, and a large number of experiments are required to detect whether their performance meets the usage requirements, which is time-consuming and laborious, and easily leads to the abandonment of newly produced rubber-coated roller wheels due to a certain parameter not meeting the requirements.

[0005] During the selection, generally, the selection parameter standards are raised. In the case where accurate comparison data cannot be obtained, the standards can only be raised again, so that the selected rubber-coated roller wheels basically meet the usage requirements. However, the improvement of performance will lead to a significant increase in the usage cost.

[0006] Therefore, there is an urgent need for a selection method that can be fast and accurate to meet the usage requirements. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide a method for selecting a rubber-coated roller wheel, which can quickly and accurately select a rubber-coated roller wheel, greatly improving the service life of the rubber-coated roller wheel.

[0008] To solve the above technical problem, the present invention provides a method for selecting a rubber-coated roller wheel, including the following steps:

[0009] Step 1) Create a design calculation model for the rubber-coated roller wheel:

[0010] Calculate the grounding angle β from the radius R of the rubber-coated roller wheel, the radial deformation ratio a of the rubber layer, and the thickness T of the rubber layer;

[0011] The grounding area s is calculated from the radius R of the rubber-coated roller, the width d of the rubber-coated roller, and the grounding angle β;

[0012] The load G is calculated from the grounding area s, the grounding coefficient m, the grounding specific pressure σ, and the safety factor n;

[0013] Among them, the radial deformation ratio a, the radius R of the rubber-coated roller, the thickness T of the rubber layer, the width d of the rubber-coated roller, the safety factor n, and the grounding coefficient m are all set values; the grounding specific pressure σ is calculated from the grounding area s;

[0014] Step 2) Set the radial deformation ratio a, the safety factor n, and the grounding coefficient m in the calculation model;

[0015] At the same time, according to the operating conditions and the design size range of the rubber-coated wheel, select the radius R of the rubber-coated roller, the width d of the rubber-coated roller, and the thickness T of the rubber layer and input them into the calculation model;

[0016] Step 3) Calculate and output the load G of the rubber-coated roller through the calculation model, that is, obtain the rated maximum static load G of a single rubber-coated roller 静 ;

[0017] Step 4) Calculate the rated maximum dynamic load G according to the maximum static load and the load rate 动 ;

[0018] Step 5) When G 静 >G 动 >M 单 , it indicates that the radius R of the rubber-coated roller, the width d of the rubber-coated roller, and the thickness T of the rubber layer selected in Step 2 meet the requirements, and the design of the rubber-coated roller is completed; in other cases, jump to Step 2) to execute.

[0019] Furthermore, in the calculation model, the following formula is used for calculation:

[0020] G = (m * s * σ) / n;

[0021] s = 2R * sinβ * d;

[0022]

[0023] Furthermore, when G 静 >G 动 >M 单 , perform a uniform horizontal motion judgment. According to the total weight m of the vehicle body and the number of rubber-coated rollers n used, calculate the bearing capacity of each rubber-coated roller, which is m / n, and obtain the friction coefficient f between the rubber-coated roller and the walking contact material in the use environment 滚 and the acceleration of gravity g, and then calculate the traction force F generated by the rubber-coated roller during uniform motion 牵 , according to F 牵Calculate the tearing force F borne by the rubber-covered roller when it is in a uniform motion state 匀速 ;

[0024] Compare F 匀速 with G 动 . When G 动 >F 匀速 , it indicates that the radius R, the width d of the rubber-covered roller, and the thickness T of the rubber layer selected in Step 2 meet the requirements, and the design of the rubber-covered roller is completed; in other cases, jump to Step 2) for execution.

[0025] Furthermore, when G 静 >G 动 >M 单 , perform an acceleration horizontal motion judgment. According to the total weight m of the vehicle body and the number n of rubber-covered rollers used, calculate the bearing capacity of each rubber-covered roller, which is m / n, and obtain the friction coefficient f between the rubber-covered roller and the walking contact material in the use environment 滚 , the acceleration of gravity g, the maximum acceleration a, and define the estimated ratio of the increase in the bearing capacity of the rubber-covered roller after the center of gravity shifts due to inertia when in an accelerated motion state;

[0026] Subsequently, calculate the traction force F generated by the rubber-covered roller during the acceleration motion 牵 . According to F 牵 , calculate the tearing force F borne by the rubber-covered roller when it is in the acceleration motion state 加速 ;

[0027] Compare F 加速 with G 动 . When G 动 >F 加速 or G 动 ≈F 加速 , it indicates that the radius R, the width d of the rubber-covered roller, and the thickness T of the rubber layer selected in Step 2 meet the requirements, and the design of the rubber-covered roller is completed; in other cases, jump to Step 2) for execution.

[0028] Furthermore, the radial deformation ratio a is 10%-15%.

[0029] Furthermore, the safety factor is 1-1.6, preferably 1.5.

[0030] Furthermore, the grounding coefficient is the ratio between the actual grounding area and the theoretically supposed contact area.

[0031] Furthermore, a comparison table is also provided. The comparison table has the load rates corresponding to different maximum uniform horizontal running speeds of the rubber-covered roller. Obtain the corresponding load rate in the comparison table according to the maximum uniform horizontal running speed of the rubber-covered roller corresponding to the vehicle body.

[0032] Further, the theoretical load per single roller distributed to each rubber-coated roller according to the total mass of the equipment is denoted as the bearing capacity M. 单 The total mass is the sum of the self-weight and the load of the equipment.

[0033] Advantages of the present invention:

[0034] By establishing a calculation model, the empirical selection is transformed into a quantitative selection. According to the conditions required under the operating conditions, an accurate and appropriate selection structure can be quickly obtained through the calculation model. According to the results, existing products can be effectively selected or prepared again, greatly improving work efficiency, and the calculation data can provide intuitive comparison data to meet the use requirements. Description of the Drawings

[0035] Figure 1 It is a schematic diagram of the overall process of the present invention. Detailed Embodiments

[0036] The present invention will be further described below in conjunction with the drawings and specific embodiments, so that those skilled in the art can better understand the present invention and be able to implement it, but the embodiments given are not intended to limit the present invention.

[0037] Embodiment 1:

[0038] Referring to Figure 1 As shown in the figure, an embodiment of a method for selecting a rubber-coated roller of the present invention. The rubber layer of the rubber-coated roller is made of polyurethane and includes the following steps:

[0039] First, create a design calculation model for the rubber-coated roller. Specifically, the grounding angle β is calculated from the radius R of the rubber-coated roller, the radial deformation ratio a of the rubber layer, and the thickness T of the rubber layer; the grounding area s is calculated from the radius R of the rubber-coated roller, the width d of the rubber-coated roller, and the grounding angle β; the load G is calculated from the grounding area s, the grounding coefficient m, the grounding specific pressure σ, and the safety factor n.

[0040] In the above calculation model, the calculation formula is as follows: G = (m * s * σ) / n

[0041] s = 2R * sinβ * d

[0042]

[0043] Among them, the radial deformation ratio a, the radius R of the rubber-coated roller, the thickness T of the rubber layer, the width d of the rubber-coated roller, the safety factor n, and the grounding factor m are all set values. The radial deformation ratio a, the safety factor n, and the grounding factor m can be preset and not modified later, while the radius R of the rubber-coated roller, the thickness T of the rubber layer, and the width d of the rubber-coated roller are set values calculated and adjusted according to the working conditions; the grounding specific pressure σ is obtained by calculating through the grounding area s, which is an existing calculation method. After the rubber layer material and the radial deformation ratio are determined, the grounding specific pressure is also determined and does not require manual setting. Different rubber layer materials have corresponding grounding specific pressures;

[0044] Before model selection, the following criteria also need to be followed:

[0045] During the actual application of the polyurethane rubber-coated roller, it bears the load through the radial deformation of the rubber surface in contact with the ground; according to the characteristics of polyurethane materials, its design criteria are as follows:

[0046] (1) Strength criterion: The grounding specific pressure is less than the compressive strength of the material;

[0047] (2) Fatigue criterion: The working grounding specific pressure is less than the fatigue strength of the material;

[0048] (3) Deformation criterion: The radial deformation strength of the rubber layer is less than the yield strength of the material;

[0049] (4) Service temperature: The actual service temperature is lower than the working temperature of polyurethane;

[0050] Boundary conditions can also be set:

[0051] Radial deformation δ s var ≤ 0.15T; Fatigue strength δ -1 ≤ 16 Mpa; Safety factor n = 1.5 (considering fatigue, service life, etc.)

[0052] Input the outer diameter 2R = φ450 mm of the rubber-coated roller, the width d = 110 mm of the rubber-coated roller (take d = 110 mm during calculation), the thickness T = 35 mm of the polyurethane rubber layer; the grounding factor m = 1, which belongs to full contact. When there are patterns on the rubber layer surface, the grounding factor will change accordingly; the grounding specific pressure (when the radial deformation ratio is a = 10%) σ ≈ 7.8 Mpa into the calculation model. Under the above parameters, the calculation model can calculate the maximum grounding area s = 8696.95 mm of the rubber-coated roller 2 ;

[0053] At this time, the rated maximum static load G of the rubber-coated roller 静 = 4610 Kgf.

[0054] The rubber-coated roller is used on the stacker. The total weight of the stacker is 13,000 Kgf and is borne by 4 rubber-coated rollers. Therefore, theoretically, a single rubber-coated roller needs to bear 3,250 Kgf;

[0055] The maximum constant horizontal running speed of the stacker is 90 m / min;

[0056] According to the comparison table of polyurethane wheel load and rim linear speed, when the speed is 1.5 m / s, the dynamic load is 90% of the static load value;

[0057] Comparison table:

[0058] Serial number Linear velocity (m / s) Load ratio 1 1.0 95％ 2 1.5 90％ 3 2.0 85％ 4 2.5 80％ 5 3.0 75％ 6 3.5 70％ 7 4.0 65％ 8 4.5 60％ 9 5.0 55％

[0059] At this time, the rated maximum dynamic load (90 m / min) G_dynamic of the rubber-coated roller = G_static * 90% = 4,149 Kgf.

[0060] At this time, G_static > G_dynamic > 3,250 Kgf;

[0061] Therefore, it can be concluded that for the rubber-coated roller with the parameters of outer diameter 2R = φ450 mm, roller width d = 110 mm, and polyurethane rubber layer thickness T = 35 mm, when the stacker is stationary, the load-bearing meets the requirements.

[0062] Based on the above conclusion, it is also possible to compare whether the requirements are met during the constant horizontal movement of the stacker. Specifically, the total weight of the stacker m = 13,000 Kgf, which consists of its own weight and the load weight, and is borne by 4 rubber-coated rollers. Theoretically, a single rubber-coated roller needs to bear 3,250 Kgf; the rolling friction coefficient f of the rubber layer made of polyurethane and steel 滚 = 0.05; gravitational acceleration g = 9.81 m / s 2 ;

[0063] At this time, in the state of constant horizontal movement:

[0064] F 牵(匀速) = F f匀速 = m / 4 * g * f 滚 = 1,594.125 N;

[0065] At this time, the tearing force borne by the rubber-coated roller in the state of constant movement is:

[0066]

[0067] Because at this time, the rated maximum dynamic load (90 m / min) G_dynamic of the rubber-coated roller = G_static * 90% = 4,149 Kgf.

[0068] G_dynamic = 4,149 Kgf > F 匀速 = 3,619.9 Kgf

[0069] Therefore, when the stacker moves horizontally at a constant speed, the rubber-coated roller meets the requirements.

[0070] During the movement of the stacker, there are not only uniform motion states, but also accelerating motion states. When in the accelerating motion state:

[0071] The total weight of the stacker is 13000 Kgf, which is borne by 4 rubber-coated rollers. Considering the problem of the center of gravity deviation caused by inertia during the accelerating motion state, that is, 120% (estimated value) of the load borne by a single wheel is equivalent to a small increase in the bearing capacity of a single wheel, that is, the single-wheel limit needs to bear 3900 Kgf;

[0072] The static friction coefficient f between the polyurethane rubber layer and steel 静 = 0.4; The gravitational acceleration g = 9.81 m / s 2 ; The maximum acceleration is 0.3 m / s 2 . At this time, in the accelerating motion state:

[0073] F f加速 = m / 4 * 120% * g * f 静 = 3900 * 9.81 * 0.4 = 15303.6 N;

[0074] At this time, F 牵(加速) = m / 4 * a + F f加速 = 13000 / 4 * 0.3 + 15303.6 = 16278.6 N

[0075] At this time, the tearing force borne by the rubber-coated roller in the accelerating motion state is:

[0076]

[0077] Because at this time, the rated maximum dynamic load (90 m / min) G of the rubber-coated roller 动 = G_static * 90% = 4149 Kgf.

[0078] G 动 = 4149 < F 加速 = 4238 Kgf.

[0079] Although in the calculation result, the rated maximum dynamic load G 动 is less than the tearing force, but the difference between the two is not large, and it can be agreed to be equivalent. In addition, through the setting of safety factors, etc., there is still room for the rubber-coated roller itself, that is, it still meets the requirements.

[0080] Summary: The rubber-coated roller meets the usage requirements when it is stationary, moving at a constant speed, and accelerating.

[0081] Example 2:

[0082] In a certain stacker project, the total mass of the stacker is 4197Kg. It uses 8 rubber-coated rollers for bearing, and they are passive wheels. The rubber layer of the rubber-coated rollers is made of MDI polyurethane 95A, the radius R of the rubber-coated roller is 100mm, the radial deformation ratio a of the rubber layer is 10%, the thickness T of the rubber layer is 20mm, the width d of the rubber-coated roller is 60mm (actual contact width), and the linear speed is 6m / s.

[0083] According to the radius R of the rubber-coated roller, the thickness T of the rubber layer and the width d of the rubber-coated roller, the grounding angle β can be directly calculated. The grounding coefficient m is 1, the grounding pressure ratio σ is 7.8 and the safety factor n is 1.5. The rated maximum static load G of the rubber-coated roller is calculated using the above parameters. 静 Calculation.

[0084] Calculate G 静 =1307.987563; According to the comparison table of line speed and load rate, we can get the load rate as 45%, thus calculating G 动 =588.5944032.

[0085] According to the total mass of the stacker and the 8 rubber-coated rollers, the theoretical load-bearing weight M of a single rubber-coated roller can be calculated. 单 is 524.625Kg, that is, G 静 >G動>M 单 .

[0086] The conclusion is: when stationary, it meets the usage requirements.

[0087] Under the condition of uniform speed, the rubber-coated roller is in contact with the steel track in the working condition, and its rolling friction coefficient is 0.05. The theoretical load-bearing weight of a single wheel is M 单 , the acceleration due to gravity is 9.81m / s 2 And the rolling friction coefficient is calculated to get F 牵(匀速) is 257.3285625N. Then calculate F 匀速 =525.2803719Kgf.

[0088] G 动 >F 匀速 , the conclusion is: when moving horizontally at a uniform speed, the requirements are met.

[0089] Under acceleration, the load of a single wheel needs to be magnified by 120%, that is, the safe load of a single wheel is 629.55Kg. The horizontal rolling friction force can be calculated to be 308.794275N, and the horizontal acceleration of the stacker is 4m / s 2 Finally, we get F 加速 =881.5193556Kgf.

[0090] G 动<F 匀速 , and the values ​​differ greatly, so it is concluded that the acceleration horizontal movement does not meet the requirements, so it is necessary to readjust the parameters of the rubber-coated roller and recalculate. By considering the influence of the horizontal and vertical inertial forces, a more accurate judgment can be achieved.

[0091] In this application, after the calculation model is determined, it is only necessary to input various parameters in the actual working conditions into the calculation model. The calculation model can quickly output the results, and the output results are used for effective comparison to accurately determine whether the parameters of the currently designed rubber-coated roller meet the requirements, thereby greatly simplifying the selection process and eliminating the need to rely on experience.

[0092] In addition, the data of the present application can be calculated by software programming, and the relevant data can be automatically calculated to obtain the results by collecting parameters; of course, EXCEL software can also be used to divide the parameters into fixed parameters, filled parameters and automatically calculated parameters. Fixed parameters are parameters that are generally not adjusted, such as safety factor, grounding factor, etc. The filled parameters are generally parameters such as load and size of the rubber-coated roller. By filling in and entering basic parameters and calculating with the function provided by EXCEL software, the required G can be quickly obtained. 动 , G 静 、M 单 、F 匀速 、F 加速 The parameters used for comparison can effectively draw conclusions, and when adjustments are needed, the results can be quickly obtained without repeated experimental verification, which greatly improves the selection efficiency. The above-mentioned embodiments are only preferred embodiments for fully illustrating the present invention, and the protection scope of the present invention is not limited thereto. Equivalent substitutions or changes made by technicians in this technical field on the basis of the present invention are all within the protection scope of the present invention.

Claims

1. A method for selecting a rubber-coated roller, characterized in that: The following steps are involved: Step 1) Create a calculation model for rubber-coated roller design: The ground contact angle β is calculated from the radius R of the rubber-coated roller, the radial deformation ratio a of the rubber layer, and the thickness T of the rubber layer; The contact area s is calculated from the radius R of the rubber-coated roller, the width d of the rubber-coated roller and the contact angle β; The load G is calculated from the ground contact area s, ground contact coefficient m, ground contact pressure σ and safety factor n; Among them, the radial deformation ratio a, the radius of the rubber-coated roller R, the thickness of the rubber layer T, the width of the rubber-coated roller d, the safety factor n and the ground contact coefficient m are all set values; the ground contact pressure σ is obtained by calculating the ground contact area s; Step 2) setting the radial deformation ratio a, safety factor n and grounding factor m in the calculation model; At the same time, according to the use conditions and the design size range of the rubber-coated wheel, the radius R of the rubber-coated roller, the width d of the rubber-coated roller and the thickness T of the rubber layer are selected and input into the calculation model; Step 3) Calculate the load G of the rubber-coated roller through the calculation model, that is, obtain the rated maximum static load G of a single rubber-coated roller. 静 ; Step 4) Calculate the rated maximum dynamic load G based on the maximum static load and load rate 动 ; Step 5) When G 静 >G 动 >M 单 When , it indicates that the rubber-coated roller radius R, the rubber-coated roller width d and the thickness T of the rubber layer selected in step 2 meet the requirements, and the rubber-coated roller design is completed; in other cases, jump to step 2) to execute; M 单 It is the load-bearing capacity that a single rubber-coated roller needs to bear.

2. The method for selecting a rubber-coated roller according to claim 1, characterized in that: In the calculation model, the following formula is used: G = (m*s*σ) / n; s = 2R*sinβ*d; 3. The method for selecting a rubber-coated roller according to claim 1, characterized in that: When G is satisfied 静 >G 动 >M 单 When the vehicle is in uniform horizontal motion, the bearing capacity of each rubber-coated roller is calculated according to the total weight m of the vehicle body and the number of rubber-coated rollers n, which is m / n. The friction coefficient f between the rubber-coated roller and the walking contact material in the use environment is obtained. 滚 , gravitational acceleration g, and then calculate the traction force F generated by the rubber-coated roller when it moves at a uniform speed 牵 , according to F 牵 Calculate the tearing force F that the rubber-coated roller is subjected to when in uniform motion 匀速 ; F 匀速 With G 动 For comparison, when G 动 >F 匀速 , it indicates that the rubber-coated roller radius R, rubber-coated roller width d and rubber layer thickness T selected in step 2 meet the requirements, and the rubber-coated roller design is completed; in other cases, jump to step 2) to execute.

4. The method for selecting a rubber-coated roller according to claim 3, characterized in that: When G is satisfied 静 >G 动 >M 单 When the vehicle is in use, the horizontal motion is judged by acceleration. According to the total weight of the vehicle body m and the number of rubber-coated rollers n, the bearing capacity of each rubber-coated roller is calculated as m / n, and the friction coefficient f between the rubber-coated roller and the walking contact material in the use environment is obtained. 滚 , gravitational acceleration g, maximum acceleration a, and the estimated ratio of the increase in the bearing capacity of the rubber-coated roller after the inertia in the accelerated motion state causes the center of gravity to shift; Then calculate the traction force F generated by the rubber-coated roller during acceleration 牵 , according to F 牵 Calculate the tearing force F that the rubber-coated roller is subjected to when in accelerated motion 加速 ; F 加速 With G 动 For comparison, when G 动 >F 加速 or G 动 ≈F 加速 , it indicates that the rubber-coated roller radius R, rubber-coated roller width d and rubber layer thickness T selected in step 2 meet the requirements, and the rubber-coated roller design is completed; in other cases, jump to step 2) to execute.

5. The method for selecting a rubber-coated roller according to claim 1, characterized in that: The radial deformation ratio a is 10%-15%.

6. The method for selecting a rubber-coated roller according to claim 1, characterized in that: The safety factor is 1-1.6, preferably 1.

5.

7. The method for selecting a rubber-coated roller according to claim 1, characterized in that: The ground contact coefficient is the ratio between the actual ground contact area and the theoretical contact area.

8. The method for selecting a rubber-coated roller according to claim 1, characterized in that: A comparison table is also provided, which contains load rates corresponding to different maximum uniform horizontal operating speeds of the rubber-coated roller. The corresponding load rate is obtained in the comparison table according to the maximum uniform horizontal operating speed of the equipment corresponding to the rubber-coated roller.

9. The method for selecting a rubber-coated roller according to claim 8, characterized in that: The theoretical load of a single wheel distributed to each rubber-coated roller according to the total mass of the equipment is recorded as the bearing capacity M 单 The total mass is the sum of the equipment's own weight and the load.

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