Floor grinding machine gear box guide plate structure parameter optimization design method

Abstract

The application provides a floor grinding machine gear box guide plate structure parameter optimization design method, which is used for determining the optimal values of three radial clearances between the guide plate and the gear tooth top. Firstly, a parameterized gear box model containing clearance as a variable is constructed, and a gear oil stirring loss theoretical model is established based on the boundary layer theory and the fluid resistance theory; taking the maximum lubrication efficiency as the target and the oil stirring power loss not exceeding the set threshold as the constraint condition, a central composite design method is used to select representative sample points in the design space; through computational fluid dynamics simulation, a moving particle semi-implicit method is used for splash lubrication transient analysis to obtain performance data of each point; based on the simulation data, a high-precision proxy model is constructed; finally, under the condition of meeting the oil stirring power loss constraint condition, the maximum lubrication efficiency is taken as the target for optimization solving to obtain the optimal clearance combination. The method realizes the quantitative design from parameters to performance, and effectively replaces the traditional trial and error method.

Description

Technical Field

[0001] This invention relates to the field of mechanical design optimization, and in particular to a method for optimizing the structural parameters of the guide plate of the gearbox of a floor grinding machine. Background Technology

[0002] Floor grinders are core equipment in modern building floor treatment. Their gearboxes, as key components of the power transmission system, directly determine the overall grinding efficiency, energy consumption, and operational reliability of the machine. To meet the demands of large-area, high-smoothness floor construction, modern high-end floor grinders generally employ multi-stage idler gear differential planetary gear transmission systems, with the input and output shafts arranged perpendicular to the ground. These gearboxes offer advantages such as compact structure and large transmission ratio, but their numerous internal gear meshing points and complex spatial configuration place extremely high demands on the lubrication system.

[0003] Currently, these gearboxes primarily employ splash lubrication. However, during operation, especially in stable working phases, the high-speed rotating gears, under centrifugal force, throw lubricating oil against the inner circumferential wall of the gearbox, forming accumulated "oil rings." This results in insufficient oil supply to the core meshing areas (such as the meshing areas between idler gears and between the idler gear and the sun gear), leading to low lubrication efficiency. Simultaneously, the continuous and vigorous agitation of the oil by the gears generates significant power loss from the agitation process, which not only reduces transmission efficiency but also causes oil temperature to rise, accelerating lubricating oil aging.

[0004] To address the aforementioned issues, existing technical solutions mostly focus on optimizing the macroscopic parameters of the gears (such as module and number of teeth) or adjusting the characteristics of the lubricating oil. These methods are all passive adjustments and cannot fundamentally optimize the complex oil flow field inside the gearbox of a floor grinder. Although theoretically, the flow field can be actively guided by introducing a baffle structure, this approach faces significant challenges in engineering practice: First, there is no mature theoretical support for determining the appropriate three-dimensional configuration of the baffle for this specific type of gearbox and how to determine its optimal installation position. Second, there is a lack of a systematic design method that can accurately quantify the mapping relationship between the baffle structural parameters and the two core performance indicators of "reducing oil churning losses" and "improving oil supply efficiency in key parts." This results in the design process heavily relying on qualitative engineering experience and time-consuming trial and error, making it impossible to achieve rapid and accurate optimization design.

[0005] Therefore, there is an urgent need in this field for a scientific optimization design method to systematically solve the parameter optimization problem of the gearbox guide plate structure of floor grinding machines. Summary of the Invention

[0006] In view of the shortcomings of the existing technology, the purpose of this invention is to provide an optimized design method for the gearbox guide plate structure of a floor grinding machine. This method can systematically and scientifically determine the optimal configuration and installation parameters of the guide plate, avoid relying on experience and trial and error, and achieve efficient and accurate optimized design.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] An optimized design method for the gearbox guide plate structure of the floor grinder includes the following steps:

[0009] S1. Determine design variables and optimization objectives: Use the radial clearance between the guide vane and the gear tooth tip as the design variable, including the radial clearance between the first guide vane and the planetary gear tooth tip. Radial clearance between the first guide vane and the tip of the second-stage idler gear Radial clearance between the second guide vane and the tip of the first-stage idler gear And the radial clearance between the first guide vane and the tip of the first-stage idler gear. The optimization objective is to maximize lubrication efficiency, while the constraint is that the loss of oil stirring power does not exceed a set threshold.

[0010] S2. Establish a theoretical model for oil churning loss: Based on boundary layer theory and fluid resistance theory, establish a calculation model for gear oil churning torque loss that includes viscous friction resistance and pressure difference resistance;

[0011] S3. Experimental Design and Flow Field Simulation: The central composite design method is used to arrange sample points. Based on the computational fluid dynamics method, the gearbox model corresponding to each sample point is subjected to splash lubrication transient simulation. The oil stirring power loss value and the number of lubricating oil particles reaching the core meshing area are extracted at each sample point.

[0012] S4. Constructing the response surface model: Based on the simulation results, the central composite response surface method is used to establish the churning power loss and lubrication efficiency with respect to the three radial clearances. The second-order response surface model;

[0013] S5. Constraint Optimization Solution: Based on the constructed response surface model, under the constraint of churning power loss, the optimization solution is performed with the objective of maximizing lubrication efficiency. The expectation function method is used to transform the objective of maximizing lubrication efficiency into an expectation function, and optimization is performed in the solution space where the churning power loss meets the constraint conditions to obtain the optimal radial clearance combination. S6. Output the optimal solution: Output the optimal radial clearance combination. The optimized design of the guide vane structure was completed.

[0014] Furthermore, in step S3, a fluid simulation method based on the semi-implicit moving particle method is used to perform transient analysis of splash lubrication.

[0015] Furthermore, in step S5, the expected function method includes the following steps: transforming the goal of maximizing lubrication efficiency into an individual expected function, wherein the value range of the individual expected function is [0,1], and the value is 1 when the response value reaches the optimal value and 0 when it exceeds the acceptable range; and optimizing the solution with the goal of maximizing the individual expected function within the solution space where the oil stirring power loss satisfies the constraint conditions.

[0016] The optimized design method provided by this invention has the following beneficial effects:

[0017] 1. Accurate and reasonable optimization objectives: Using lubrication efficiency as the optimization objective and oil stirring power loss as the constraint condition is more in line with actual engineering needs and ensures that the optimization results have better practicality.

[0018] 2. Systematized and scientific design process: Numerical simulation, experimental design, approximate modeling and optimization algorithms are organically combined to form a complete and quantitative parameter design process, replacing the traditional experience-based trial and error method.

[0019] 3. High efficiency and low cost: CFD simulation and approximate models significantly reduce the number of physical experiments, shorten the design cycle, and reduce R&D costs.

[0020] 4. Strong global optimization results: The advanced optimization algorithm can effectively find the parameter combination with better performance and robustness, ensuring that the guide vane structure can achieve the best overall performance.

[0021] 5. The method has good versatility: This method is not only applicable to the optimization of the guide vane parameters of the specific gearbox, but its core process can also be extended to other complex fluid machinery design problems that require balancing multiple performance objectives. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the internal structure of the gearbox of the floor grinding machine of the present invention.

[0023] Figure 2 This is a top view of the interior of the gearbox of the present invention.

[0024] Figure 3 This is a flowchart of the optimized design method of the present invention.

[0025] Figure 4 This is a schematic diagram comparing the distribution of lubricating oil inside the gearbox before and after optimization of the method of the present invention.

[0026] Figure 5The diagram shows the oil volume distribution curves in the meshing area of ​​the first-stage and second-stage idler wheels before and after the optimization of the method of the present invention.

[0027] Figure 6 The diagram shows the oil volume distribution curves in the meshing area between the sun gear and the first-stage idler gear before and after the optimization of the method of the present invention.

[0028] Attached diagram labels: Sun gear 1, First-stage idler gear 2, Second-stage idler gear 3, Planetary gear 4, Housing 5, First guide vane 6, Second guide vane 7. Detailed Implementation

[0029] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] refer to Figure 1 The floor grinder gearbox of this invention adopts a multi-stage idler differential planetary gear transmission system, including a sun gear 1, a first-stage idler gear 2, a second-stage idler gear 3, planetary gears 4, and a housing 5. A first guide plate 6 and a second guide plate 7 are fixedly installed on the inner circumferential wall of the gearbox in the lubricating oil accumulation area using fasteners. The gearbox is a multi-stage idler differential planetary gear transmission system, and the axes of its input and output shafts are perpendicular to the ground.

[0031] refer to Figure 2 The main body of the first guide plate 6 and the second guide plate 7 is a three-dimensional curved surface configuration. Its shape is composed of multiple arcs that are concentric with the axis of each gear. It is used to receive the lubricating oil that is thrown to the box wall by centrifugal force, and to guide the oil to the core meshing area (such as the meshing area between idler gears, or between idler gear and sun gear) by the hydrodynamic pressure generated by the revolution of the gearbox.

[0032] The radial clearance between the guide vane structure and the gear tooth tip includes: the radial clearance between the first guide vane 6 and the planetary gear 4 tooth tip. Radial clearance between the tip of the first guide vane 6 and the tooth tip of the second-stage idler wheel 3, and between the tip of the second guide vane 7 and the tooth tip of the first-stage idler wheel 2. And the radial clearance between the first guide vane 6 and the tooth tip of the first-stage idler wheel 2. The These are the optimal parameters determined through multi-objective optimization.

[0033] The curved surface shapes of the first guide plate 6 and the second guide plate 7 are composed of multiple arcs that are concentric with the shafts of each gear, and their outlines are adapted to the flow field traces inside the gearbox.

[0034] refer to Figure 3 The optimized design method for the gearbox guide plate structure of the floor grinding machine of the present invention includes the following steps:

[0035] S1. Determine design variables and optimization objectives: The radial clearance between the first guide vane 6 and the tip of the planetary gear 4 is used as the basis. Radial clearance between the tip of the first guide vane 6 and the tooth tip of the second-stage idler wheel 3, and between the tip of the second guide vane 7 and the tooth tip of the first-stage idler wheel 2. Radial clearance between the first guide vane 6 and the tooth tip of the first-stage idler wheel 2 As a design variable; with the optimization objective of maximizing lubrication efficiency, and the constraint that the oil stirring power loss does not exceed 6% of the total power;

[0036] S2. Establish a theoretical model for oil churning loss: Based on boundary layer theory and fluid resistance theory, establish a calculation model for gear oil churning torque loss that includes viscous friction resistance and pressure difference resistance. This model specifically includes:

[0037] The total churning resistance is contributed by both viscous friction resistance and pressure difference resistance:

[0038] Viscous friction is further decomposed into viscous friction on the gear circumferential surface and viscous friction on the gear end face:

[0039]

[0040] The viscous friction force on the gear end face is calculated using the infinitesimal element method. The Reynolds number is used to distinguish between laminar and turbulent flow states, and the corresponding calculation formulas are used for each:

[0041] The Reynolds number is calculated as follows:

[0042] in The characteristic length is denoted as .

[0043] Pressure drag is calculated using the pressure difference between the upstream and downstream sides of the integral tooth surface:

[0044]

[0045] Calculation of gear churning torque:

[0046] in The effective radius of action.

[0047] Calculation of power loss in gear churning:

[0048] in This is the angular velocity of the gear driven by the input motor.

[0049] Power loss percentage:

[0050] S3. Experimental Design and Flow Field Simulation: The central composite design method is used to arrange sample points. Based on the computational fluid dynamics method, the gearbox model corresponding to each sample point is subjected to splash lubrication transient simulation. The oil stirring power loss value and the number of lubricating oil particles reaching the core meshing area are extracted at each sample point.

[0051] Central composite design implementation method:

[0052] This embodiment employs a three-factor, five-level central composite design, specifically including:

[0053] Design factors:

[0054] Factor A: (Radial clearance between the No. 1 guide vane and the planetary gear tooth tip);

[0055] Factor B: (Radial clearance between the first guide vane and the tip of the second-stage idler gear, and clearance between the second guide vane and the tip of the first-stage idler gear);

[0056] Factor C: (Radial clearance between the No. 1 guide vane and the tip of the first-stage idler gear).

[0057] Design level settings:

[0058] Each factor has five levels: low level (-α), low level (-1), center point (0), high level (+1), and high level (+α). The α value is 1.682 (calculated based on α=2^(3 / 4), and k=3 is the number of factors).

[0059] Sample point composition:

[0060] The total number of sample points is 19, including: 8 cubic points (factor design points), 6 star points (axial points), and 5 center points (repeated experiment points).

[0061] In step S3, a meshless fluid simulation method based on the moving particle semi-implicit method (MPS) is used to perform transient analysis of splash lubrication. This method is based on the following governing equations:

[0062] Continuity equation:

[0063] Equations of motion:

[0064] Particle interaction model:

[0065] In the formula, and All are coordinate vectors of the particles; The number density constant is the particle number density. The desired spatial dimension; These are the physical parameters of the particle.

[0066] Lubrication efficiency quantification model:

[0067] Based on CFD simulation results, the lubrication efficiency is quantified by the volume fraction of lubricating oil in the core meshing region:

[0068] S4. Constructing the response surface model: Based on the simulation results, the central composite response surface method is used to establish the churning power loss and lubrication efficiency with respect to the three radial clearances. The second-order response surface model;

[0069]

[0070] in For response value, For design variables, For regression coefficients, This is the error term.

[0071] S5. Constraint Optimization Solution: Based on the constructed response surface model, under the constraint of churning power loss, optimization is performed with the objective of maximizing lubrication efficiency. The expectation function method is used to transform the objective of maximizing lubrication efficiency into an expectation function, and optimization is performed in the solution space where the churning power loss meets the constraint conditions to obtain the optimal radial clearance combination. ;

[0072] Mathematical formulation of the optimization problem:

[0073]

[0074] Construction of the expectation function:

[0075] In step S5, the individual expectation function D The value range is [0,1]. When the response value reaches the optimal value, it takes the value of 1, and when it exceeds the acceptable range, it takes the value of 0.

[0076] S6. Output the optimal solution: Based on the optimal solution obtained in S5, output the optimal radial clearance combination. The optimized design of the guide vane structure was completed.

[0077] refer to Figure 4 Through the guide plate structure and optimization method of the present invention, the lubricating oil accumulated on the tank wall (in its unoptimized state, such as...) can be effectively diverted. Figure 44a) guides the lubrication to the core meshing area (optimized state, as shown in 4b), significantly improving lubrication and reducing power loss.

[0078] refer to Figure 5 and Figure 6 The optimized guide vane structure significantly improves lubrication. Experimental data shows that the optimized guide vane structure increases the lubricating oil coverage in the meshing area of ​​the first-stage and second-stage idler gears from 9.23% to 75.51%, and the lubricating oil coverage in the meshing area of ​​the sun gear and the first-stage idler gear from 12.34% to 80.14%, while keeping the churning power loss consistently below 6% of the total power.

[0079] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for optimizing the structural parameters of the guide plate of the gearbox in a floor grinding machine, characterized in that, Includes the following steps: S1. Determine design variables and optimization objectives: The radial clearance between the guide vane and the gear tooth tip is used as the design variable, including the radial clearance between the first guide vane and the planetary gear tooth tip, the radial clearance between the first guide vane and the second-stage idler gear tooth tip, the radial clearance between the second guide vane and the first-stage idler gear tooth tip, and the radial clearance between the first guide vane and the first-stage idler gear tooth tip; the optimization objective is to maximize lubrication efficiency, and the constraint condition is that the oil stirring power loss does not exceed the set threshold. S2. Establishing a theoretical model and experimental design: Based on boundary layer theory and fluid resistance theory, a theoretical model of gear churning loss is established, and a central composite design method is used to arrange sample points in the design space; The theoretical model for gear churning loss includes: establishing a calculation model for gear churning torque loss that includes viscous friction resistance and pressure difference resistance, based on boundary layer theory and fluid resistance theory; S3. Flow field simulation and data acquisition: Based on computational fluid dynamics, splash lubrication transient simulation is performed on the gearbox model corresponding to each sample point to obtain the churning power loss value and lubrication efficiency value of each sample point. S4. Constructing response surface models: Based on simulation data, second-order response surface models of oil stirring power loss and lubrication efficiency with respect to design variables are established using the central composite response surface method. S5. Constraint Optimization Solution: Based on the constructed response surface model, under the constraint of oil stirring power loss, the optimization solution is performed with the goal of maximizing lubrication efficiency to obtain the optimal radial clearance combination. S6. Output optimization results: Output the optimal radial clearance combination to complete the parameter optimization design of the guide vane structure.

2. The optimization design method according to claim 1, characterized in that: In step S3, a meshless fluid simulation method based on the semi-implicit moving particle method is used to perform transient analysis of splash lubrication.

3. The optimization design method according to claim 1, characterized in that: In step S5, the objective of maximizing lubrication efficiency is transformed into an expectation function using the expectation function method, and then optimized within the solution space where the oil stirring power loss satisfies the constraint conditions.

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