A method for optimizing the transmission efficiency of a speed reducer

Abstract

The present invention relates to a method for optimizing the transmission efficiency of a speed reducer. The method includes: Step 1, presenting the expressions for the transmission efficiency of the speed reducer and various power losses; Step 2, extracting the structural parameters and operating conditions parameters that can be used to optimize the transmission efficiency of the speed reducer; Step 3, establishing a simulation analysis model for the transmission efficiency of the speed reducer, analyzing the relationship between the structural parameters and operating conditions parameters extracted in Step 2 and the transmission efficiency, and selecting at least 5 parameters with the greatest influence as the preferred parameters for orthogonal experiments; Step 4, optimizing the transmission efficiency of the speed reducer through designing an orthogonal experiment scheme, simulation analysis, and optimization result evaluation, and finally obtaining the optimal parameter combination that meets the evaluation requirements. The entire optimization process of the present invention comprehensively considers influencing factors, is more in line with the actual operation situation, has a wide application range, and is not limited to speed reducers with specific structures, that is, for speed reducers with different structures, this optimization method can be used to greatly improve the transmission efficiency.

Description

Technical Field

[0001] The present invention relates to a method for optimizing the transmission efficiency of a speed reducer, belonging to the technical field of speed reducers. Background Art

[0002] As an important component in mechanical equipment, speed reducers are widely used in fields such as construction, vehicles, ships, aerospace, and mines. The improvement of the energy-saving level of speed reducers in industrial production is mainly reflected in the improvement of their transmission efficiency.

[0003] The level of the transmission efficiency of a speed reducer is related to the amount of power loss of the speed reducer. Power loss reflects the problem of energy loss during the operation of the speed reducer. Different application scenarios of the speed reducer have different main energy loss types. For the speed reducer of a cement grinding roller press that mainly consumes electrical energy, the electrical energy consumption cost accounts for 20%-30% of the total production cost, and the electrical energy consumption of the grinding system accounts for 60%-70% of the total electrical energy consumption.

[0004] The main methods for optimizing the transmission efficiency of speed reducers are orthogonal experiments and genetic algorithms. However, the optimization objectives selected in the existing optimization methods are only to reduce the unilateral power loss, and the optimization parameters only select the gear structure parameters or operating conditions parameters, without comprehensive consideration, ignoring many influencing factors. This method is difficult to significantly improve the transmission efficiency of speed reducers. In addition, during the process of optimizing the transmission efficiency of speed reducers, many existing methods only optimize the meshing efficiency and oil agitation of a single pair of gears, and the optimization of the transmission efficiency of speed reducers is not comprehensive. Moreover, this optimization method does not consider the influence of some factors such as shaft deformation and bearings during the operation of the speed reducer, which does not conform to the actual working conditions. Therefore, the practicability of optimizing the transmission efficiency of speed reducers is poor and the optimization degree is low.

[0005] For example, Chinese patent document CN105782428A discloses a method and device for optimizing the transmission ratio of an automotive transmission. The method includes determining optimization parameters; establishing an objective function according to the optimization purpose of automotive transmission parameters; establishing constraint conditions; establishing a mathematical optimization model and solving the model to obtain the optimized transmission ratios of the transmission and the main speed reducer; inputting the optimized transmission ratios of the transmission and the main speed reducer into a dynamic and economic simulation matching model for calculation, and determining whether the dynamic and economic requirements are met. If so, the process ends. If not, the constraint conditions or the optimization model are modified and the model is solved again, and the dynamic and economic simulation matching model is simulated until the dynamic and economic requirements are met. However, this solution only addresses the problem of passively selecting and testing the matching of existing engine and transmission resources in an automobile. By selecting the gear ratios of each gear and the main speed reducer ratio, the transmission ratio closest to the dynamic and economic objectives is obtained. This solution is relatively micro and specific, different from the method for optimizing the transmission efficiency of unspecified speed reducers from a macro and multi-factor perspective in the present application.

[0006] For another example, Chinese Patent Document CN106777411A discloses a multi-objective optimization of the main reducer gear of a drive axle. The method includes the first step: for the research of the main reducer gear of the drive axle, taking the transmission efficiency, torque transmission capacity and contact ratio of the main reduction gear as the objective functions, and establishing a multi-objective optimization mathematical model for the main reducer gear transmission; the second step: adopting a fast non-dominated sorting genetic algorithm with an elite strategy to optimize the design of the main reducer gear transmission, and obtaining the Pareto optimal solution; the third step: selecting an optimization scheme from them and comparing it with the original design scheme. The multi-objective optimization of the main reducer gear of the present invention shows that the transmission efficiency of the main reducer gear has a significant increase, and both the torque transmission capacity and the contact ratio have a certain improvement. Although this scheme selects the target parameters and analyzes them, obtains the optimizable optimal solution of the parameters, and selects the optimization scheme to compare with the original scheme to obtain the optimal scheme for improving the transmission efficiency of the reducer. However, the target selection parameters of this scheme are relatively single. Although it can improve the transmission efficiency to a certain extent, there is still a large room for improvement.

[0007] With the maturity and development of the simulation analysis technology of the reducer transmission system, it provides conditions for the accurate simulation detection of the reducer transmission efficiency and the analysis of the main influencing factors. However, at present, few people conduct systematic research on the modeling of the reducer transmission efficiency, the analysis of influencing factors and the parameter optimization technology.

[0008] Therefore, designing an efficient optimization method for the reducer transmission efficiency is an urgent problem to be solved in current industrial production. Summary of the Invention

[0009] Aiming at the deficiencies of the prior art, the present invention provides an optimization method for the reducer transmission efficiency. This method has wide adaptability and is not limited to a certain type of reducer. Moreover, it comprehensively considers the structural parameters and working condition parameters of the reducer itself, and can maximize the transmission efficiency of the reducer.

[0010] The technical solution of the present invention is as follows:

[0011] An optimization method for the reducer transmission efficiency includes the following steps:

[0012] Step 1, analyze the reducer transmission efficiency and the power losses that determine the reducer transmission efficiency, and propose the expressions of the reducer transmission efficiency and each power loss;

[0013] Step 2, obtain the main influencing parameters of the reducer transmission efficiency according to each power loss expression and conduct analysis, and extract the structural parameters and working condition parameters that can optimize the reducer transmission efficiency;

[0014] Step 3: Establish a simulation analysis model for the transmission efficiency of the reducer, and conduct a simulation analysis on the transmission efficiency of the reducer, that is, analyze the relationship between the structural parameters and working conditions parameters extracted in Step 2 and the transmission efficiency, and select at least 5 parameters with the greatest influence as the optimal parameters for the orthogonal experiment;

[0015] Step 4: For the optimal parameters of the orthogonal experiment selected in Step 3, optimize the transmission efficiency of the reducer by designing an orthogonal experiment plan, simulation analysis, and optimization result evaluation, and finally obtain the optimal parameter combination that meets the evaluation criteria.

[0016] Preferably, in Step 1, the expression for the transmission efficiency of the reducer is:

[0017]

[0018] In the formula: η is the transmission efficiency; P in is the input power of the reducer, in kW; P out is the output power of the reducer, in kW;

[0019] The main types of power losses generated by the reducer are: gear meshing power loss, bearing friction power loss, oil churning power loss, and oil seal friction power loss. That is, the total power loss of the reducer can be expressed as:

[0020] P Z =P G +P B +P C +P S (Ⅱ)

[0021] In the formula: P Z is the total power loss of the reducer, in kW; P G is the gear meshing power loss, in kW; P B is the bearing friction power loss, in kW; P C is the oil churning power loss, in kW; P S is the oil seal friction power loss, in kW;

[0022] Then formula (Ⅰ) can also be expressed as:

[0023]

[0024] The expressions for each power loss are:

[0025] P G =P GS +P GR (Ⅲ)

[0026] In the formula: P GS is the gear sliding friction power loss, in kW; P GR is the gear rolling friction power loss, in kW;

[0027] Among them, the formula for the power loss due to sliding friction of the gear is:

[0028]

[0029] In the formula: is the average sliding friction coefficient; F N is the normal load on the tooth surface, N; m n is the normal module, mm; i is the average transmission ratio of the gears; X E is the influence coefficient of contact ratio;

[0030] The formula for the power loss due to rolling friction of the gear is:

[0031]

[0032] In the formula: h d is the elastic oil film thickness, mm; n1 is the rotational speed of the driving gear, r / min; B is the tooth width, mm; β is the helix angle; r1 is the pitch circle radius of the driving gear; α′ is the pressure angle; ε1, ε2 are the contact ratios before and after the meshing node;

[0033]

[0034] In the formula, M is the frictional torque of the bearing, N·mm; n b —is the rotational speed of the bearing, r / min;

[0035]

[0036] In the formula, ρ is the density of the lubricating oil, kg / m 3 ; ω is the angular velocity of the gear, rad / s; r a —is the addendum circle radius, mm; r is the pitch circle radius, mm; h t —is the total tooth height, mm; C1 is the calculation coefficient of the oil churning resistance torque on the side surface of the gear; C2 is the calculation coefficient of the oil churning resistance torque on the circumferential surface of the gear;

[0037]

[0038] In the formula, d S —is the diameter of the shaft section where the oil seal is located, mm; F S —is the frictional force per unit length of the shaft circumference, N / mm; n S —is the rotational speed of the shaft where the oil seal is located, r / min.

[0039] Preferably, the specific steps of the second step include the following steps:

[0040] From each power loss expression, the factors that affect the transmission efficiency of the reducer can be extracted: normal modulus, transmission ratio, speed, torque, tooth width, helix angle, lubricating oil density, oil immersion depth, and lubricating oil kinematic viscosity; when the lubricating oil is selected for the reducer, the lubricating oil density and lubricating oil kinematic viscosity depend on the lubricating oil temperature, so the lubricating oil temperature is used for unified expression.

[0041] Among the above parameters, the structural parameters include: normal modulus, transmission ratio (number of teeth), tooth width, helix angle; the operating parameters include: speed, torque, oil immersion depth, lubricating oil temperature;

[0042] However, among the above structural parameters, the normal modulus has a greater influence on the bending strength of the gear, and the reducer has certain requirements for the transmission ratios of each gear, so it is not appropriate to optimize these parameters; among the operating parameters, the reducer generally has certain requirements for the output speed and torque, and the input speed is determined according to the transmission ratio, so it cannot be optimized.

[0043] Finally, the structural parameters that can be optimized are extracted, including tooth width and helix angle, and the operating parameters include oil immersion depth and lubricating oil temperature.

[0044] Preferably, the step three is based on the Romax Designer software platform to model and simulate the reducer, and select the optimal parameters required for the orthogonal test according to the simulation analysis results, which specifically includes the following steps:

[0045] 1) Reducer entity modeling, which is used to establish a reducer entity model, including shafts, bearings, gears, oil seals, and reducer outer shells. Specifically, it is to determine the specific parameters of each component in the reducer, locate the components according to the location of each component, locate the entire transmission system according to the position of the shaft and the center distance of the gears, and store these parameters for subsequent calls;

[0046] The shaft parameters include: shaft section length, shaft end diameter, material, and surface treatment form;

[0047] The gear parameters include: normal module, pressure angle, helix angle, helix direction, number of teeth, tooth width, accuracy grade, material, and displacement coefficient; if it is a planetary gear, the parameters include: normal module, pressure angle, number of planetary gears, number of teeth, standard pitch diameter, tooth width, material, and transmission ratio;

[0048] The oil seal parameters include: inner diameter, outer diameter, and width;

[0049] For the bearings, only the bearing model needs to be selected.

[0050] 2) Input of reducer operating parameters, which is used to determine the input operating parameters of the reducer to simulate the actual working environment of the reducer. The specific operating parameters include: input power, power input and output positions, input speed, input torque, immersion depth, lubricating oil temperature, continuous working time of the reducer, and these parameters are stored for subsequent calls.

[0051] 3) Analysis of the relationship between the optimizable parameters and the transmission efficiency of the reducer, which is used to establish a simulation analysis model for the transmission efficiency of the reducer, and then conduct a simulation analysis on the relationship between each structural parameter and operating parameter that can be optimized and the transmission efficiency. Specifically:

[0052] Based on the creation of the reducer solid model and the definition of operating parameters, select the transmission efficiency analysis standard as ISO14179-2(DE) for analysis;

[0053] For the analysis of operating parameters, start the transmission efficiency simulation analysis module on the main interface of Romax Designer software, set the variation range of the simulation analysis operating parameter values, fix the reducer structural parameters as the parameters used in the reducer solid modeling step, and according to the principle of changing one parameter while keeping the others unchanged, analyze the relationship between each operating parameter and the transmission efficiency of the reducer respectively, obtain the specific values of the transmission efficiency during the change of the operating parameters, and store the analysis result data in the specified location for subsequent analysis;

[0054] The operating parameters for the transmission efficiency simulation analysis of the reducer include: immersion depth, lubricating oil temperature; the value range of the immersion depth is l h -6mm ≤ l h ≤ l h ≤ l + 6mm, and the value range of the lubricating oil temperature is 30°C ≤ T ≤ 75°C;

[0055] For the analysis of structural parameters, start the transmission efficiency simulation analysis module on the main interface of Romax Designer software, set the simulation analysis operating parameters as the rated operating input parameters, and the structural parameters for the reducer simulation analysis are modified from the structural parameters in the reducer solid modeling step. According to the principle of changing one parameter while keeping the others unchanged, analyze the relationship between each structural parameter and the transmission efficiency of the reducer respectively. Among them, for the analysis of the gear structural parameters, it is the analysis of the relationship between the single structural parameter of each stage of gears and the transmission efficiency, obtain the specific values of the transmission efficiency during the change of the structural parameters, and store the analysis result data in the specified location for subsequent analysis;

[0056] The structural parameters for the transmission efficiency simulation analysis of the reducer include: tooth width of each stage of gears, helix angle of each stage of gears; the value range of the gear tooth width is 0.9B ≤ B ≤ 1.1B, and the value range of the helix angle is β - 5° ≤ β ≤ β + 5°;

[0057] 4) Evaluation of the simulation analysis results of the preferred parameters, which is used to extract the structural parameters and working condition parameters that have a greater impact on the transmission efficiency of the reducer, so as to be used as the preferred parameters required for the orthogonal test of optimizing the transmission efficiency of the reducer. Specifically:

[0058] First, retrieve the analysis results of the transmission efficiency of the reducer, read the maximum and minimum values of the transmission efficiency during the change of each analysis parameter, and calculate the amplitude of the change in the transmission efficiency;

[0059] Secondly, compare the amplitudes of the changes in the transmission efficiency corresponding to each analysis parameter, and select the parameter with the largest amplitude of change as the preferred parameter for the orthogonal test; when the reducer is a two-stage reducer, select 5 parameters with the largest amplitudes of change as the preferred parameters for the orthogonal test; when the reducer is a three-stage reducer, select 6 parameters with the largest amplitudes of change as the preferred parameters for the orthogonal test; when the reducer is a four-stage reducer, select 7 parameters with the largest amplitudes of change as the preferred parameters for the orthogonal test, and so on;

[0060] Finally, take the selected parameters as the preferred parameters for the transmission efficiency of the reducer, and classify the determined number of preferred parameters into structural parameters and working condition parameters.

[0061] Preferably, step 4 is based on the Romax Designer software platform, and the method of orthogonal test is used to optimize the parameters of the transmission efficiency of the reducer. Taking the improvement of the transmission efficiency of the reducer as the test index and meeting the gear strength check standard as the constraint condition, the specific steps are as follows:

[0062] 1) Design of the orthogonal test scheme. According to the simulation analysis results of the transmission efficiency, the immersion depth l h , lubricating oil temperature T, gear tooth width B, and helix angle β are selected as influencing factors;

[0063] Among them, when the gear is a spur gear or a helical gear, the tooth width B is represented by the tooth width of the large gear. When it is a planetary gear, the tooth width B is represented by the tooth width of the sun gear. The tooth width of the small gear is fixed and increased by 5 - 10 mm on the basis of the tooth width of the large gear. The tooth width of the ring gear is equal to the tooth width of the sun gear, and the tooth width of the planetary gear is fixed and increased by 5 - 10 mm compared with the tooth width of the sun gear;

[0064] The value range set for the influencing factors is as follows: the value range of the immersion depth is l h -6 mm ≤ l h ≤ l h ≤ l + 6 mm, the value range of the lubricating oil temperature is 30°C ≤ T ≤ 75°C, the value range of the gear tooth width is 0.9B ≤ B ≤ 1.1B, and the value range of the helix angle is β - 5° ≤ β ≤ β + 5°;

[0065] Determine the division levels of the influence factors according to the number of selected influence factors. When 5 influence factors are selected, divide them into four levels, that is, select 4 values evenly within their respective value ranges, and formulate the L 16 (4 5 ) orthogonal experiment table to obtain 16 groups of experimental schemes; when 6 influence factors are selected, divide them into five levels, that is, select 5 values evenly within their respective value ranges, and formulate the L 25 (5 6 ) orthogonal experiment table to obtain 25 groups of experimental schemes; when 7 influence factors are selected, divide them into six levels, that is, select 6 values evenly within their respective value ranges, and formulate the L 36 (6 7 ) orthogonal experiment table to obtain 36 groups of experimental schemes, and so on;

[0066] 2) Use Romax Designer software to modify the structural parameters and working condition parameters of the established entity model according to each group of experimental schemes, conduct simulation analysis, and obtain the numerical values of the transmission efficiency of the reducer corresponding to each group of experimental schemes;

[0067] Then, adopt the range analysis method to obtain the primary and secondary order of the influence of each influence factor on the transmission efficiency of the reducer, and obtain the optimal parameters of each influence factor. Combine the optimal parameters of each influence factor to obtain the optimal parameter combination of the transmission efficiency of the reducer.

[0068] 3) Evaluation of orthogonal experiment results, which is used to analyze and evaluate the transmission efficiency and gear strength of the reducer after parameter optimization. Specifically:

[0069] Sort the optimal parameter combinations according to the principle that the change amplitude of the transmission efficiency of the optimized reducer compared with that of the non-optimized reducer is from large to small. The optimal parameter combination with the largest increase is No. 1, followed by No. 2, and so on;

[0070] During the parameter optimization process, since the gear structural parameters are involved, it is necessary to check the strength of the gear after parameter optimization; first, call the gear parameter part in the reducer entity modeling module and modify it to the gear optimized parameters in the No. 1 experiment; second, use the built-in gear strength check function in Romax Designer software, select the check standard as ISO 6336:2006, and check the strength of the gear in the No. 1 experiment. If the gear strength check in the No. 1 experiment shows "pass", stop the strength check; if the gear strength check in the No. 1 experiment shows "fail", then check the strength of the No. 2 experiment until finally a group of optimized parameters with the largest increase in the transmission efficiency of the reducer and meeting the gear strength check are found.

[0071] Preferably, in the fourth step, the evaluation criterion refers to maximizing the improvement in the transmission efficiency of the reducer while simultaneously meeting the requirements of gear strength verification.

[0072] Technical features and beneficial effects of the present invention:

[0073] 1. Based on the theoretical calculation formula of the internal power loss of the reducer, the present invention preliminarily analyzes the influencing factors of the transmission efficiency of the reducer, and builds a dedicated optimization system for the transmission efficiency of the reducer, which can analyze and extract the working condition parameters and structural parameters that have a greater impact on the transmission efficiency of the reducer. The orthogonal test method is used to optimize the parameters of the transmission efficiency of the reducer, and it can verify whether the reducer meets the requirements of gear strength verification after parameter optimization.

[0074] 2. Compared with the traditional optimization method for the transmission efficiency of the reducer, the entire optimization process comprehensively considers the influencing factors, uses modeling technology to realize the solid modeling of the reducer, which is more in line with the actual working conditions, has a greater degree of improvement in transmission efficiency, the dedicated optimization system for the transmission efficiency of the reducer is easy to operate, has a wide application range, and strong applicability.

[0075] 3. The optimization method for the transmission efficiency of the reducer of the present invention has strong universality and is not limited to reducers with specific structures. That is, for reducers with different structures, this optimization method can be used to greatly improve the transmission efficiency of the reducer, realize the environmental protection concept of energy conservation and emission reduction, and has high economic efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0076] Figure 1 It is a flowchart of the optimization method for the transmission efficiency of the reducer of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0077] The present invention will be further described below by way of examples in conjunction with the drawings, but is not limited thereto.

[0078] Optimization refers to taking certain measures for a certain thing to make it excellent. In the present invention, it mainly means that there is room for improvement in a single parameter.

[0079] Preference refers to selecting one or several best solutions from multiple solutions. In the present invention, it mainly means selecting one or several parameters from multiple parameters.

[0080] Combined with the attached Figure 1 drawings, the technical solution of the present invention will be more intuitively described. The present invention provides an optimization method for the transmission efficiency of a reducer, including the following steps:

[0081] Step 1, analyze the transmission efficiency of the reducer and the power losses that determine the transmission efficiency of the reducer, and propose expressions for the transmission efficiency of the reducer and each power loss;

[0082] Step 2: Analysis of the main influencing parameters of the reducer transmission efficiency and extraction of optimizable parameters. Based on the power loss expression, the main influencing parameters of the reducer transmission efficiency are obtained and analyzed, and the structural parameters and operating parameters for optimizing the reducer transmission efficiency parameters are extracted;

[0083] Step 3: Determination of the optimized parameters of the reducer transmission efficiency based on simulation analysis. The reducer transmission efficiency is simulated and analyzed, the relationship between the optimizable parameters and the transmission efficiency is analyzed, and at least 5 parameters with the greatest influence are extracted as the optimized parameters for the orthogonal experiment;

[0084] Step 4: Optimization of the reducer transmission efficiency parameters based on the orthogonal experiment method. Through designing the orthogonal experiment scheme, simulation analysis, and optimization result evaluation, the reducer transmission efficiency is optimized, and finally the optimal parameter combination that meets the evaluation requirements is obtained.

[0085] The specific implementation process of this technical solution is as follows:

[0086] Step 1 specifically includes: The calculation of the reducer transmission efficiency depends on the magnitudes of the input power and the output power. The input power is usually a fixed input value, while the output power is related to the power loss generated during the operation of the reducer. Therefore, the transmission efficiency can be expressed by the following formula:

[0087]

[0088] In the formula: η is the transmission efficiency; P in is the input power of the reducer, in kW; P out is the output power of the reducer, in kW.

[0089] The output power of the reducer depends on the power losses generated by each component during the operation process, mainly including the power losses of gears, bearings, oil seals, and other auxiliary mechanisms. The power losses of these components can be divided into two categories: load power losses and non-load power losses; Load power losses refer to the power losses generated due to continuous friction or relative slip speed at the contact surface of each power transmission component during the process of transmitting force, mainly including the frictional power losses generated during the meshing process of gears and the bearing frictional power losses; Non-load power losses refer to the components in the transmission system that rotate in the box but do not transmit power, mainly including the power losses caused by oil agitation and oil seals.

[0090] It is summarized that the main types of power losses generated by the reducer are: gear meshing power losses, bearing frictional power losses, oil agitation power losses, and oil seal frictional power losses. That is, the total power loss of the reducer can be expressed as:

[0091] P Z = P G + P B + PC +P S (Ⅱ)

[0092] Where: P Z is the total power loss of the reducer, kW; P G is the gear meshing power loss, kW; P B is the bearing friction power loss, kW; P C is the oil stirring power loss, kW; P S is the oil seal power loss, kW.

[0093] Formula (I) can be converted into:

[0094]

[0095] When the specific values of gear meshing power loss, bearing friction power loss, oil stirring power loss and oil seal power loss can be determined, the transmission efficiency of the reducer can be calculated by the above formula.

[0096] The expressions of various power losses in the reducer are as follows:

[0097] 1) The gear meshing power loss is composed of sliding friction and rolling friction between the tooth surfaces, which can be expressed by the following formula:

[0098] P G =P GS +P GR (III)

[0099] Where: P GS is the gear sliding friction power loss, kW; P GR is the gear rolling friction power loss, kW.

[0100] The gear sliding friction power loss formula is:

[0101]

[0102] Where: is the average sliding friction coefficient; F N is the normal load on the tooth surface, N; m n is the normal module, mm; i is the average transmission ratio of the gear; X E is the overlap influence coefficient. X E Confirm by searching in reference books.

[0103] The formula for gear rolling friction power loss is:

[0104]

[0105] Where: h dis the elastic oil film thickness, in mm; n1 is the rotational speed of the driving wheel, in r / min; B is the tooth width, in mm; β is the helix angle; r1 is the pitch circle radius of the driving wheel; α′ is the angle of engagement; ε1 and ε2 are the contact ratios before and after the meshing node. Among them, ε1 and ε2 are determined by looking up in reference books.

[0106] 2) The bearing friction power loss is mainly determined by the bearing friction torque and rotational speed, and its formula is:

[0107]

[0108] In the formula, M is the bearing friction torque, in N·mm; n b —is the bearing rotational speed, in r / min.

[0109] 3) The oil churning power loss includes gear oil churning and bearing oil churning. The oil churning power loss caused by the bearing is negligible compared to the gear oil churning power loss. Therefore, only the gear oil churning part is considered in the formula for the oil churning power loss, and the formula is:

[0110]

[0111] In the formula, ρ is the density of the lubricating oil, in kg / m 3 ; ω is the angular velocity of the gear, in rad / s; r a —is the addendum circle radius, in mm; r is the pitch circle radius, in mm; h t —is the total tooth height, in mm; C1 is the calculation coefficient of the oil churning resistance torque on the gear side; C2 is the calculation coefficient of the oil churning resistance torque on the gear circumferential surface. Among them, the values of the oil churning resistance torque calculation coefficient C1 on the gear side and the oil churning resistance torque calculation coefficient C2 on the gear circumferential surface depend on the immersion depth, tooth width, and kinematic viscosity of the lubricating oil, and are determined by looking up in reference books.

[0112] 4) The oil seal power loss in the reducer is mainly the power loss generated due to the relative movement caused by the friction between the oil seal and the shaft, and can be expressed as:

[0113]

[0114] In the formula, d S —is the diameter of the shaft section where the oil seal is located, in mm; F S —is the frictional force per unit length of the shaft circumference, in N / mm; n S —is the rotational speed of the shaft where the oil seal is located, in r / min.

[0115] Among them, step two specifically includes: analysis of the main influencing factors of the reducer transmission efficiency and extraction of optimizable parameters, and the specific steps are as follows:

[0116] In order to optimize the transmission efficiency of the reducer, it is necessary to reduce the power losses in four aspects: gear meshing, bearing friction, oil stirring and oil seal. Among them, bearings are standard parts, and their parameters are not suitable for optimization. Replacing high-precision bearings to improve bearing power loss is costly and has small benefits. The power loss caused by oil seals is negligible compared to that caused by gears and bearings, and the practicality of optimizing them is low. Therefore, the present invention optimizes the transmission efficiency of the reducer mainly by reducing the gear meshing power loss and the oil stirring power loss.

[0117] From the above power loss formula, we can extract the factors that affect the transmission efficiency of the reducer: normal modulus, transmission ratio, speed, torque, tooth width, helix angle, lubricating oil density, oil immersion depth, and lubricating oil kinematic viscosity. Among them, there is a certain relationship between lubricating oil density and lubricating oil kinematic viscosity, which can be uniformly expressed by lubricating oil kinematic viscosity. After the reducer selects the lubricating oil, its lubricating oil kinematic viscosity depends on the lubricating oil temperature, so the lubricating oil temperature is used for uniform expression.

[0118] Among the above parameters, the structural parameters include: normal module, transmission ratio (number of teeth), tooth width, and helix angle;

[0119] The operating parameters include: speed, torque, oil immersion depth, and lubricating oil temperature.

[0120] However, among the above structural parameters, the normal modulus has a greater influence on the bending strength of the gear, and the reducer has certain requirements for the transmission ratios of each gear, so it is not appropriate to optimize these parameters; among the operating parameters, the reducer generally has certain requirements for the output speed and torque, and the input speed is determined according to the transmission ratio, so it cannot be optimized.

[0121] Therefore, the structural parameters that can be optimized include: tooth width, helix angle;

[0122] The operating parameters that can be optimized include: oil immersion depth and lubricating oil temperature.

[0123] The third step is to model and simulate the reducer based on the Romax Designer software platform, and determine the optimal parameters required for the orthogonal test according to the simulation analysis results, which specifically includes the following steps:

[0124] 1) Reducer entity modeling, which is used to establish a reducer entity model, including shafts, bearings, gears, oil seals, and reducer outer shells. Specifically, it is to determine the specific parameters of each component in the reducer, locate the components according to the location of each component, locate the entire transmission system according to the position of the shaft and the center distance of the gears, and store these parameters for subsequent calls;

[0125] The shaft parameters include: shaft section length, shaft end diameter, material, and surface treatment form;

[0126] The gear parameters include: normal module, pressure angle, helix angle, helix direction, number of teeth, tooth width, accuracy grade, material, modification coefficient; for planetary gears, the parameters include: normal module, pressure angle, number of planetary gears, number of teeth, standard pitch diameter, tooth width, material, transmission ratio;

[0127] The oil seal parameters include: inner diameter, outer diameter, width;

[0128] For the bearing, only select the bearing model. The bearing is a standard part, and corresponding parameters are available for the bearing model.

[0129] 2) Input of reducer operating condition parameters, which is used to determine the input operating condition parameters of the reducer to simulate the actual working environment of the reducer. The specific operating condition parameters include: input power, power input and output positions, input speed, input torque, lubricating oil temperature, continuous working time of the reducer, and these parameters are stored for subsequent calls.

[0130] 3) Analysis of the relationship between the preferable parameters and the transmission efficiency of the reducer, which is used to establish a simulation analysis model for the transmission efficiency of the reducer, and then conduct a simulation analysis on the relationship between each structural parameter and operating condition parameter that can be optimized and the transmission efficiency. Specifically:

[0131] Based on the creation of the reducer solid model and the definition of operating condition parameters, select ISO14179-2(DE) as the analysis standard for transmission efficiency analysis. This standard is included in the software and can be directly selected within the software. DE represents the German version of this standard.

[0132] For the analysis of operating condition parameters, start the transmission efficiency simulation analysis module on the main interface of Romax Designer software, set the variation range of the simulation analysis operating condition parameters, and fix the reducer structural parameters as those used in the reducer solid modeling step. According to the principle of changing one parameter while keeping the others unchanged, analyze the relationship between each operating condition parameter and the transmission efficiency of the reducer respectively, obtain the specific values of the transmission efficiency during the change of operating condition parameters, and store the analysis result data in a specified location for subsequent analysis;

[0133] The operating condition parameters for the transmission efficiency simulation analysis of the reducer include: immersion depth, lubricating oil temperature; the value range of the immersion depth is l h -6mm ≤ l h ≤ l h ≤ l + 6mm, and the value range of the lubricating oil temperature is 30°C ≤ T ≤ 75°C;

[0134] For the analysis of structural parameters, start the simulation analysis module of the reducer transmission efficiency in the main interface of Romax Designer software. Set the simulation analysis working condition parameters as the rated working condition input parameters. The structural parameters for the reducer simulation analysis are obtained by modifying the structural parameters in the reducer solid modeling steps. According to the principle of changing one parameter while keeping the others unchanged, analyze the relationship between each structural parameter and the reducer transmission efficiency. Among them, for the analysis of gear structural parameters, it is the analysis of the relationship between the single structural parameter of each stage of gears and the transmission efficiency. Obtain the specific values of the transmission efficiency during the change of structural parameters, and store the analysis result data in the specified location for subsequent analysis;

[0135] The structural parameters for the reducer simulation analysis of transmission efficiency include: the tooth width of each stage of gears, the helix angle of each stage of gears; the value range of the gear tooth width is 0.9B ≤ B ≤ 1.1B, and the value range of the helix angle is β - 5° ≤ β ≤ β + 5°;

[0136] The simulation analysis program of the reducer transmission efficiency is carried out by Romax Designer software and is applicable to all versions above Romax Designer R17 and below R20.

[0137] 4) Evaluation of the simulation analysis results of the preferred parameters, which is used to extract the structural parameters and working condition parameters that have a greater impact on the reducer transmission efficiency, so as to be used as the preferred parameters for the orthogonal test of optimizing the reducer transmission efficiency. Specifically:

[0138] First, retrieve the analysis results of the reducer transmission efficiency, read the maximum and minimum values of the transmission efficiency during the change of each analysis parameter, and calculate the amplitude of the transmission efficiency change;

[0139] Secondly, compare the amplitudes of the transmission efficiency changes corresponding to each analysis parameter, and select the parameter with the largest change amplitude as the preferred parameter for the orthogonal test. When the reducer is a two-stage reducer, select 5 parameters with the largest change amplitudes (5 parameters with the change amplitudes decreasing in order from the largest) as the preferred parameters for the orthogonal test. When the reducer is a three-stage reducer, select 6 parameters with the largest change amplitudes as the preferred parameters for the orthogonal test. When the reducer is a four-stage reducer, select 7 parameters with the largest change amplitudes as the preferred parameters for the orthogonal test, and so on. For example, for a two-stage reducer, 5 parameters with the change amplitudes decreasing in order from the largest can be selected: the immersion depth, the lubricating oil temperature, the tooth width of the first-stage gears, the tooth width of the second-stage gears, and the helix angle of the first-stage gears;

[0140] Finally, take the selected parameters as the preferred parameters of the reducer transmission efficiency, and classify the determined number of preferred parameters into structural parameters and working condition parameters.

[0141] Among them, Step 4 is to optimize the parameters of the reducer transmission efficiency by using the orthogonal experiment method based on the Romax Designer software platform. Taking the improvement of the reducer transmission efficiency as the test index and meeting the gear strength check standard as the constraint condition, the specific steps are as follows:

[0142] 1) Design of the orthogonal experiment plan. According to the simulation analysis results of the transmission efficiency, select the immersion depth l h , lubricating oil temperature T, gear tooth width B, and helix angle β as influencing factors;

[0143] Among them, when the gear is a spur gear or a helical gear, the tooth width B is represented by the tooth width of the large gear; when it is a planetary gear, the tooth width B is represented by the tooth width of the sun gear; the tooth widths of the pinion, planetary gear, and ring gear are regarded as related factors and change accordingly with the changes of the tooth widths of the large gear and the sun gear. The tooth width of the pinion is fixed and increased by 5 - 10 mm based on the tooth width of the large gear, the tooth width of the ring gear is equal to the tooth width of the sun gear, and the tooth width of the planetary gear is fixed and increased by 5 - 10 mm compared with the tooth width of the sun gear;

[0144] The value ranges set for the influencing factors are as follows: the value range of the immersion depth is l h -6 mm ≤ l h ≤ l h ≤ l + 6 mm, the value range of the lubricating oil temperature is 30°C ≤ T ≤ 75°C, the value range of the gear tooth width is 0.9B ≤ B ≤ 1.1B, and the value range of the helix angle is β - 5° ≤ β ≤ β + 5°;

[0145] Determine the division levels of the influencing factors according to the number of selected influencing factors. When the number of selected influencing factors is 5, divide them into four levels, that is, uniformly select 4 values within their respective value ranges, and formulate an L 16 (4 5 ) orthogonal experiment table to obtain 16 groups of experiment plans; when the number of selected influencing factors is 6, divide them into five levels, that is, uniformly select 5 values within their respective value ranges, and formulate an L 25 (5 6 ) orthogonal experiment table to obtain 25 groups of experiment plans. When the number of selected influencing factors is 7, divide them into six levels, that is, uniformly select 6 values within their respective value ranges, and formulate an L 36 (6 7 ) orthogonal experiment table to obtain 36 groups of experiment plans, and so on;

[0146] 2) Use the Romax Designer software to modify the structural parameters and working conditions parameters of the established solid model according to each group of experiment plans, conduct simulation analysis, and obtain the numerical values of the reducer transmission efficiency corresponding to each group of experiment plans;

[0147] Then, the range analysis method is adopted to obtain the primary and secondary order of the influence of each influencing factor on the transmission efficiency of the reducer, and the optimal parameters of each influencing factor are obtained. The optimal parameters of each influencing factor are combined to obtain the optimal parameter combination of the transmission efficiency of the reducer.

[0148] 3) Evaluation of the orthogonal test results, which is used to analyze and evaluate the transmission efficiency of the reducer and the gear strength after parameter optimization. The specific steps are as follows:

[0149] The optimal parameter combinations are sorted according to the principle of the change amplitude of the transmission efficiency of the optimized reducer compared with that of the non-optimized reducer from large to small. The optimal parameter combination with the largest increase is No. 1, followed by No. 2, and so on;

[0150] During the parameter optimization process, since the gear structure parameters are involved, it is necessary to check the strength of the gears after parameter optimization. First, call the gear parameter part in the reducer solid modeling module and modify it to the gear optimization parameters in the No. 1 test. Secondly, use the built-in gear strength check function in Romax Designer software, select the check standard as ISO 6336:2006, and check the strength of the gears in the No. 1 test. If the strength check of the No. 1 test gear shows "pass", the strength check is stopped; if the strength check of the No. 1 test gear shows "fail", the strength check of the No. 2 test is carried out until a set of optimized parameters with the largest increase in transmission efficiency and meeting the gear strength check is found, which is the optimal parameter combination of the transmission efficiency of the reducer optimized by the orthogonal test.

[0151] Example 1:

[0152] For the two-stage spur gear reducer used in a car, the above technical solution is used to optimize the transmission efficiency of the reducer.

[0153] Specifically, after the reducer solid modeling, working condition parameter input and analysis of the relationship between the optimizable parameters and the transmission efficiency of the reducer are carried out in step three, five parameters with the largest change amplitudes (five parameters with the change amplitudes decreasing in sequence from the largest) are selected as the orthogonal test optimization parameters in the evaluation of the analysis results, so as to be used as the optimization parameters for the orthogonal test of the transmission efficiency of the reducer in the subsequent step four.

[0154] In step four, when designing the orthogonal experiment plan, since this embodiment is a two-stage spur gear reducer, the tooth width B is represented by the tooth width of the large gear, and the tooth width of the small gear is fixed to increase by 5-10 mm on the basis of the tooth width of the large gear. The selected influencing factors (i.e., the five orthogonal test optimization parameters selected in step three) are divided into four levels, that is, four values (arithmetic progression) are evenly selected within their value ranges respectively, and L 16 (4 5)Orthogonal test table to obtain 16 groups of test schemes. Then, use Romax Designer software to modify the structural parameters and operating conditions parameters of the established entity model according to the 16 groups of test schemes, conduct simulation analysis, and obtain the reducer transmission efficiency values corresponding to each group of test schemes (that is, obtain 16 values).

[0155] Example 2:

[0156] For the two-stage planetary gear reducer on the scraper conveyor, use the above technical solution to optimize the reducer transmission efficiency.

[0157] Specifically, after conducting the reducer entity modeling, inputting the operating conditions parameters, and analyzing the relationship between the preferable parameters of the reducer transmission efficiency and the influence of the transmission efficiency in step three, select 5 parameters with the largest change amplitudes (5 parameters in descending order of change amplitude) as the preferable parameters for the orthogonal test in the subsequent step four for optimizing the reducer transmission efficiency as the preferable parameters for the orthogonal test of the reducer transmission efficiency optimization.

[0158] In step four, when designing the orthogonal experimental scheme, since this embodiment is a two-stage planetary gear reducer, the tooth width B is represented by the tooth width of the sun gear; the tooth widths of the planet gears and the ring gear are regarded as related factors and change correspondingly with the change of the tooth width of the sun gear. The tooth width of the ring gear is equal to the tooth width of the sun gear, and the tooth width of the planet gear is fixedly increased by 5 - 10 mm compared with the tooth width of the sun gear. Divide the selected influencing factors (i.e., the 5 preferable parameters for the orthogonal test selected in step three) into four levels, that is, uniformly select 4 values (arithmetic progression) within their value ranges respectively, and formulate L 16 (4 5 )Orthogonal test table to obtain 16 groups of test schemes. Then, use Romax Designer software to modify the structural parameters and operating conditions parameters of the established entity model according to the 16 groups of test schemes, conduct simulation analysis, and obtain the reducer transmission efficiency values corresponding to each group of test schemes (that is, obtain 16 values).

[0159] The above is only the specific implementation manner of the present invention, and the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered by the protection scope of the present invention.

Claims

1. A method for optimizing the transmission efficiency of a speed reducer, characterized in that, It includes the following steps: Step 1: Analyze the transmission efficiency of the reducer and the power losses that determine the transmission efficiency of the reducer, and propose expressions for the transmission efficiency of the reducer and various power losses; The expression for the transmission efficiency of the reducer is: Where: η is the transmission efficiency; P in is the input power of the reducer, in kW; P out is the output power of the reducer, in kW; The main types of power losses generated by the reducer are: gear meshing power loss, bearing friction power loss, oil churning power loss, and oil seal friction power loss. That is, the total power loss of the reducer can be expressed as: P Z = P G + P B + P C + P S (II) Where: P Z is the total power loss of the reducer, in kW; P G is the power loss due to gear meshing, in kW; P B is the power loss due to bearing friction, in kW; P C is the power loss due to oil churning, in kW; P S is the power loss due to oil seal friction, in kW; Then Equation (Ⅰ) can also be expressed as: The expressions for various power losses are: P G = P GS + P GR (III) Where: P GS is the power loss due to sliding friction of the gear, in kW; P GR is the power loss due to rolling friction of the gear, in kW; Among them, the formula for the sliding friction power loss of the gear is: In the formula: is the average sliding friction coefficient; F N is the normal load on the tooth surface, N; m n is the normal module, in mm; i is the average transmission ratio of the gears; X E is the influence coefficient of contact ratio; The formula for the rolling friction power loss of the gear is: where: h d is the elastic oil film thickness, in mm; n1 is the rotational speed of the driving gear, in r / min; B is the tooth width, in mm; β is the helix angle; r1 is the pitch circle radius of the driving gear; α′ is the contact angle; ε1 and ε2 are the contact ratios before and after the contact point where M is the bearing frictional torque, N·mm; n b is the bearing rotational speed, r / min; where ρ is the density of the lubricating oil, kg / m 3 ; ω is the angular velocity of the gear, rad / s; r a —the radius of the addendum circle, mm; r is the radius of the pitch circle, mm; h t —the total tooth height, mm; C1 is the calculation coefficient of the oil churning resistance moment on the side of the gear; C2 is the calculation coefficient of the oil churning resistance moment on the circumferential surface of the gear; where d S — the diameter of the shaft section where the oil seal is located, in mm; F S — the frictional force per unit length of the shaft circumference, in N / mm; n S — the rotational speed of the shaft where the oil seal is located, in r / min; Step 2: Obtain the main influencing parameters of the transmission efficiency of the reducer according to the expressions of various power losses and conduct an analysis, and extract the structural parameters and operating conditions parameters that can optimize the transmission efficiency of the reducer; Step 3: Establish a simulation analysis model for the transmission efficiency of the reducer, conduct a simulation analysis on the transmission efficiency of the reducer, that is, analyze the relationship between the structural parameters and operating conditions parameters extracted in Step 2 and the transmission efficiency, and select at least 5 parameters with the greatest influence as the preferred parameters for the orthogonal experiment; Step 4: For the preferred parameters of the orthogonal experiment selected in Step 3, optimize the transmission efficiency of the reducer through designing an orthogonal experiment scheme, simulation analysis, and optimization result evaluation, and finally obtain the optimal parameter combination that meets the evaluation criteria; The above Step 4 is based on the Romax Designer software platform, and uses the method of orthogonal experiment to optimize the parameters of the transmission efficiency of the reducer. Taking the improvement of the transmission efficiency of the reducer as the test index and meeting the gear strength check standard as the constraint condition, the specific steps are as follows: 1) Orthogonal test scheme design. According to the simulation analysis results of transmission efficiency, the immersion depth l h , lubricating oil temperature T, gear tooth width B, and helix angle β are selected as influencing factors; Among them, when the gear is a spur gear or a helical gear, the tooth width B is represented by the tooth width of the large gear. When it is a planetary gear, the tooth width B is represented by the tooth width of the sun gear. The tooth width of the small gear is fixed to increase by 5 - 10 mm based on the tooth width of the large gear. The tooth width of the ring gear is equal to the tooth width of the sun gear, and the tooth width of the planetary gear is fixed to increase by 5 - 10 mm compared with the tooth width of the sun gear; The value range of the influence factor setting is as follows: the value range of the oil immersion depth is l h -6mm ≤ l h ≤ l h ≤ l + 6mm, the value range of the lubricating oil temperature is 30°C ≤ T ≤ 75°C, the value range of the gear tooth width is 0.9B ≤ B ≤ 1.1B, and the value range of the helix angle is β - 5° ≤ β ≤ β + 5°; Determine the division levels of the influencing factors according to the number of selected influencing factors. When 5 influencing factors are selected, divide them into four levels, that is, select 4 values evenly within their respective value ranges, and formulate an L 16 (4 5 ) orthogonal experiment table to obtain 16 groups of experimental schemes; when 6 influencing factors are selected, divide them into five levels, that is, select 5 values evenly within their respective value ranges, and formulate an L 25 (5 6 ) orthogonal experiment table to obtain 25 groups of experimental schemes; when 7 influencing factors are selected, divide them into six levels, that is, select 6 values evenly within their respective value ranges, and formulate an L 36 (6 7 ) orthogonal experiment table to obtain 36 groups of experimental schemes, and so on; 2) Use the Romax Designer software to modify the structural parameters and operating conditions parameters of the established solid model according to each test scheme, conduct a simulation analysis, and obtain the numerical value of the transmission efficiency of the reducer corresponding to each test scheme; Then use the range analysis method to obtain the primary and secondary order of the influence of each influencing factor on the transmission efficiency of the reducer, and obtain the optimal parameters of each influencing factor. Combine the optimal parameters of each influencing factor to obtain the optimal parameter combination of the transmission efficiency of the reducer; 3) Evaluation of the orthogonal experiment results, which is used to analyze and evaluate the transmission efficiency of the reducer and the gear strength after parameter optimization. Specifically: Sort the optimal parameter combinations in the order of the change amplitude of the transmission efficiency of the optimized reducer compared with that of the non-optimized reducer from large to small. The optimal parameter combination with the largest increase is No. 1, followed by No. 2, and so on; During the parameter optimization process, since gear structure parameters are involved, it is necessary to check the strength of the gears after parameter optimization. First, call the gear parameter part in the reducer solid modeling module and modify it to the gear optimization parameters in Test No.

1. Second, use the built-in gear strength check function in Romax Designer software, select ISO 6336:2006 as the check standard, and check the strength of the gears in Test No.

1. If the strength check of the gears in Test No. 1 shows "Pass", stop the strength check. If the strength check of the gears in Test No. 1 shows "Fail", check the strength of the gears in Test No. 2 until a set of optimization parameters with the largest increase in the transmission efficiency of the reducer and meeting the gear strength check are finally found.

2. The method for optimizing the transmission efficiency of a speed reducer according to claim 1, wherein The specific steps of Step 2 are as follows: From each power loss expression, the factors that affect the transmission efficiency of the reducer can be extracted as: normal module, transmission ratio, rotational speed, torque, tooth width, helix angle, lubricating oil density, immersion depth, and kinematic viscosity of the lubricating oil. When the lubricating oil for the reducer is selected, the magnitudes of the lubricating oil density and the kinematic viscosity of the lubricating oil depend on the lubricating oil temperature, so the lubricating oil temperature is used for unified representation. Among the above parameters, the structure parameters include: normal module, transmission ratio (number of teeth), tooth width, helix angle; the operating parameters include: rotational speed, torque, immersion depth, and lubricating oil temperature. However, among the above structure parameters, the normal module has a greater impact on the bending strength of the gear, and the reducer has certain requirements for the transmission ratios of each stage of gears, so it is not suitable to optimize these parameters; among the operating parameters, the reducer generally has certain requirements for the output rotational speed and torque, and the input rotational speed is determined according to the transmission ratio, so it cannot be optimized. Finally, the structure parameters that can be optimized are extracted as: tooth width, helix angle, and the operating parameters include: immersion depth, lubricating oil temperature.

3. The method for optimizing the transmission efficiency of a speed reducer according to claim 1, characterized in that, Step 3 is based on the Romax Designer software platform to model and simulate the reducer, and select the optimization parameters required for the orthogonal test according to the simulation analysis results. The specific steps are as follows: 1) Reducer solid modeling, which is used to establish the reducer solid model, including shafts, bearings, gears, oil seals, and reducer housing. Specifically: determine the specific parameters of each component in the reducer, position the components according to their locations, perform overall positioning of the transmission system based on the positions of the shafts and the center distance of the gears, and store these parameters for subsequent calls. The parameters of the shaft include: shaft section length, shaft end diameter, material, and surface treatment form. The gear parameters include: normal module, pressure angle, helix angle, helix direction, number of teeth, tooth width, accuracy grade, material, and modification coefficient; if it is a planetary gear, the parameters include: normal module, pressure angle, number of planetary gears, number of teeth, standard pitch diameter, tooth width, material, and transmission ratio. The oil seal parameters include: inner diameter, outer diameter, and width. For the bearing, only select the bearing model. 2) Input of reducer operating conditions parameters, which is used to determine the input operating conditions parameters of the reducer to simulate the actual working environment of the reducer. The specific operating conditions parameters include: input power, power input and output positions, input speed, input torque, immersion depth, lubricating oil temperature, continuous working time of the reducer, and store these parameters for subsequent calls; 3) Analysis of the relationship between the preferable parameters of the reducer transmission efficiency and the influence of transmission efficiency, which is used to establish a simulation analysis model of the reducer transmission efficiency, and then conduct a simulation analysis on the relationship between each structural parameter and operating conditions parameter that can be optimized and the transmission efficiency. Specifically: Based on the creation of the reducer entity model and the definition of operating conditions parameters, select the transmission efficiency analysis standard as ISO 14179-2(DE) for analysis; For the analysis of operating conditions parameters, start the reducer transmission efficiency simulation analysis module on the main interface of Romax Designer software, set the value range of the simulation analysis operating conditions parameter changes, the reducer structural parameters are fixed as the parameters used in the reducer entity modeling step. According to the principle that one parameter changes while the others remain unchanged, analyze the relationship between each operating conditions parameter and the reducer transmission efficiency respectively, obtain the specific values of the transmission efficiency during the change of operating conditions parameters, and store the analysis result data in the specified location for subsequent analysis; The working condition parameters for the simulation analysis of the transmission efficiency of the reducer include: oil immersion depth, lubricating oil temperature; the value range of the oil immersion depth is l h -6 mm ≤ l h ≤ l h ≤ +6 mm, and the value range of the lubricating oil temperature is 30°C ≤ T ≤ 75°C; For the analysis of structural parameters, start the reducer transmission efficiency simulation analysis module on the main interface of Romax Designer software, set the simulation analysis operating conditions parameters as the rated operating conditions input parameters, and the reducer simulation analysis structural parameters are modified by changing the structural parameters in the reducer entity modeling step. According to the principle that one parameter changes while the others remain unchanged, analyze the relationship between each structural parameter and the reducer transmission efficiency respectively. Among them, for the analysis of gear structural parameters, it is the analysis of the relationship between the single structural parameter of each stage of gears and the transmission efficiency, obtain the specific values of the transmission efficiency during the change of structural parameters, and store the analysis result data in the specified location for subsequent analysis; The reducer transmission efficiency simulation analysis structural parameters include: tooth width of each stage of gears, helix angle of each stage of gears; the value range of the gear tooth width is 0.9B≤B≤1.1B, and the value range of the helix angle is β - 5°≤β≤β + 5°; 4) Evaluation of the simulation analysis results of preferable parameters, which is used to extract the structural parameters and operating conditions parameters that have a greater impact on the reducer transmission efficiency as the preferable parameters required for the orthogonal experiment of optimizing the reducer transmission efficiency. Specifically: First, retrieve the reducer transmission efficiency analysis results, read the maximum and minimum values of the transmission efficiency during the change of each analysis parameter, and calculate the amplitude of the transmission efficiency change; Secondly, compare the amplitudes of the changes in transmission efficiency corresponding to each analysis parameter, and select the parameter with the largest amplitude of change as the optimized parameter for the orthogonal experiment; when the reducer is a two-stage reducer, select 5 parameters with the largest amplitudes of change as the optimized parameters for the orthogonal experiment, when the reducer is a three-stage reducer, select 6 parameters with the largest amplitudes of change as the optimized parameters for the orthogonal experiment, when the reducer is a four-stage reducer, select 7 parameters with the largest amplitudes of change as the optimized parameters for the orthogonal experiment, and so on; Finally, take the selected parameters as the optimized parameters for the transmission efficiency of the reducer, and classify the determined number of optimized parameters into structural parameters and operating parameters.

4. The method for optimizing the transmission efficiency of a speed reducer according to claim 1, wherein In the fourth step described above, the evaluation criterion refers to maximizing the increase in the transmission efficiency of the reducer while simultaneously meeting the requirements of gear strength verification.

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