A method for constructing a transmission precision calculation model of an RV reducer considering component errors

Abstract

This invention discloses a method for constructing a calculation model for the transmission accuracy of an RV reducer that considers component errors. The method includes: constructing an equivalent mechanical model: based on the lumped parameter method, the sun gear, planetary carrier, etc., are considered rigid bodies, and gear meshing and bearing support are equivalent to linear springs; assuming assumptions such as constant sun gear speed, a coordinate system and a follower coordinate system are established, generalized micro-displacement parameters (including translational and rotational degrees of freedom) are defined, and a generalized micro-displacement column vector is constructed to clarify the mechanical characterization of the multi-degree-of-freedom system; establishing a system mechanical equation set: based on the error decomposition principle, combined with errors such as sun gear manufacturing eccentricity and crankshaft cam eccentricity, deformation coordination equations for sun gear support and gear meshing are constructed; the gear meshing stiffness, bearing support stiffness, and elastic force are correlated to construct physical equations; force balance equations are established through force analysis of each component, and a system of mechanical equations for transmission accuracy is formed. Solving these equations allows for the calculation of the transmission accuracy of the RV reducer.

Description

Technical Field

[0001] This invention belongs to the field of RV reducer technology, and relates to the field of RV reducer transmission accuracy calculation, and particularly to a method for constructing an RV reducer transmission accuracy calculation model that considers component errors. Background Technology

[0002] The RV reducer is a two-stage crank-type closed differential gear precision reducer developed from cycloidal pinwheel transmission. It has advantages such as small size, light weight, compact structure, large transmission range, strong load capacity, high motion accuracy, and high transmission efficiency. It is widely used in high-precision transmission fields such as industrial robots and aerospace. Its transmission accuracy is a key indicator for measuring product quality.

[0003] RV reducers have numerous components and complex structures. Manufacturing errors (such as eccentricity in the sun gear, crankshaft cam, and cycloidal wheel shaft hole position) and assembly errors can all cause input and output angle deviations. Angle error refers to the deviation between the actual and theoretical angles of the output shaft, i.e., transmission error, which is an important indicator for evaluating the transmission accuracy of RV reducers. Furthermore, these errors are coupled, and the overall transmission error is not a simple summation of the errors in each part, making the analysis of its transmission accuracy difficult.

[0004] Domestic and international scholars have conducted extensive research on the transmission accuracy of RV reducers. Internationally, Professor Blanche used a purely geometric method to derive the rotational accuracy of a single cycloidal pinwheel planetary reducer; Teruaki Hidaka proposed using an equivalent spring model to establish an error analysis model for the rotational transmission of RV reducers. Domestic research has also deepened. Li Wei et al. used probability theory to calculate the dominant factors affecting transmission accuracy; Han Linshan constructed a mathematical model of the transmission accuracy of a cycloidal pinwheel system based on nonlinear dynamics; Yang Yuhu applied the principle of incremental action lines to build an error model; and Zhao Haiming et al. established a mathematical model of error distribution. Furthermore, while the application of virtual prototyping technology provides an effective approach for transmission accuracy research, existing methods still have shortcomings: on the one hand, they neglect the coupled effects of multiple factors such as component geometric errors, cycloidal wheel profile clearance, and time-varying tooth meshing stiffness, leading to deviations in calculation results; on the other hand, the models are highly complex, have poor operability, and are difficult to meet practical engineering needs.

[0005] In summary, in order to calculate the transmission accuracy of RV reducers and thus support their design optimization, error control and performance improvement, there is an urgent need for a transmission accuracy calculation model that can comprehensively consider the influence of multiple factors, calculate accurately and is highly operable. Summary of the Invention

[0006] The purpose of this invention is to overcome the imperfections of existing RV reducer transmission accuracy calculation models and provide a method for constructing an RV reducer transmission accuracy calculation model. By constructing a transmission accuracy calculation model that comprehensively considers the geometric errors of components, the cycloidal wheel profile clearance, and the time-varying meshing stiffness of gear teeth, the transmission accuracy of the RV reducer can be calculated, providing a reliable method for the design optimization, error control, and performance improvement of the RV reducer.

[0007] This invention provides a method for constructing a calculation model for the transmission accuracy of an RV reducer that considers component errors, comprising the following steps:

[0008] Based on the lumped parameter method, the parts with large mass and small deformation in the RV reducer are regarded as rigid bodies, and the parts with large elasticity and negligible mass influence are regarded as linear springs. A global static coordinate system and a follower coordinate system are established, a generalized micro-displacement parameter is defined, and a micro-displacement column vector is constructed. Based on the principle of error decomposition and combined with the geometric errors of components, a deformation coordination equation is established; physical equations are constructed by relating gear meshing stiffness, bearing support stiffness and elastic force; and force balance equations are established for each component. By simultaneously establishing the micro-displacement column vector, deformation compatibility equation, physical equation, and force balance equation, a transmission accuracy calculation model is obtained. The transmission accuracy of the RV reducer is then calculated using this model.

[0009] The present invention also provides a device for constructing a calculation model for the transmission accuracy of an RV reducer that takes into account component errors.

[0010] The present invention also provides a computer device.

[0011] The present invention also provides a computer-readable storage medium.

[0012] Compared with existing technologies, the following beneficial effects can be achieved: (1) The present invention comprehensively considers the coupling effects of multiple factors such as the geometric error of RV reducer components, the cycloidal wheel profile clearance and the time-varying meshing stiffness of the gear teeth. The transmission accuracy calculation model constructed is more in line with the actual working conditions and avoids the calculation deviation caused by neglecting key factors or simplifying the error coupling effect in the existing methods. (2) The present invention constructs an equivalent mechanical model based on the lumped parameter method, which simplifies the complex structure and force relationship; the solution is convenient and fast, and can be automatically solved by programming software such as MATLAB. There is no need to perform complex geometric relationship derivation, which reduces the calculation difficulty and makes it easier to apply in engineering design and manufacturing. (3) This invention is applicable to various types of RV reducers. It can analyze the influence of errors of various components on transmission accuracy, and provide a theoretical basis for reducer design optimization (such as error distribution and shape parameter design), manufacturing process improvement (such as precision control of key components) and performance testing, which helps to improve the accuracy of RV reducers. Attached Figure Description

[0013] Figure 1 This is a schematic diagram illustrating the construction process of the transmission accuracy calculation model in an embodiment of the present invention.

[0014] Figure 2 This is a schematic diagram of the equivalent mechanical model of the RV reducer system of the present invention; Figure 3 This is a schematic diagram of the installation error of the sun gear in the RV reducer of the present invention; Figure 4 This is a schematic diagram illustrating the manufacturing eccentricity error of the sun gear and planet gears in the RV reducer of this invention; Figure 5 This is a schematic diagram showing the positional error of the cycloidal wheel shaft hole in the RV reducer of the present invention; Figure 6 This is a schematic diagram of the crankshaft cam eccentricity error in the RV reducer of the present invention; Figure 7 This is a schematic diagram illustrating the error between the cycloidal wheel and the needle tooth in the RV reducer of the present invention; Figure 8 This is a schematic diagram of the positional error of the planetary carrier shaft hole in the RV reducer of the present invention; Figure 9 This is a schematic diagram of the planetary carrier installation error in the RV reducer of the present invention; Figure 10 This is a schematic diagram of the radial runout error and cumulative pitch deviation of the cycloidal pinwheel obtained from the verification of the accuracy calculation model of the RV reducer system in a specific embodiment of the present invention. Figure 11 This is a schematic diagram showing the transmission error results obtained from the accuracy calculation model verification of the RV reducer system in a specific embodiment of the present invention. Detailed Implementation

[0015] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention.

[0016] Please see Figure 1 The present invention provides a method for constructing a calculation model for the transmission accuracy of an RV reducer that considers component errors, comprising the following steps: S1. Constructing an equivalent mechanical model of the RV reducer: Based on the lumped parameter method, the parts in the RV reducer with large mass and small deformation are regarded as rigid bodies, and the parts with large elasticity and negligible mass influence (such as gear meshing parts and bearings) are regarded as linear springs. A coordinate system and a follower coordinate system are established, generalized micro-displacement parameters are defined, and an equivalent mechanical model is established.

[0017] In one embodiment, the sun gear and planet carrier are considered as rigid bodies; the sun gear-planet gear meshing pair, the cycloidal wheel-pin tooth meshing pair, and each bearing support (sun gear support bearing, crankshaft-cycloidal wheel bearing, crankshaft-planet carrier bearing, planet carrier main bearing) are all equivalent to linear springs with corresponding stiffness.

[0018] In the equivalent mechanical model, both gear meshing and bearing support effects are represented by springs; the stiffness of the equivalent support spring for the sun gear is represented by... Indicates: Sun wheel and planetary wheel The meshing stiffness between them is used Indicates; the The first cycloidal wheel and the first The support stiffness of the needle roller bearings between the crankshafts is used Indicates, along the coordinate axis and The component is and Planetary support and the first The supporting stiffness of the bearings between the crankshafts is used Indicates, along the coordinate axis and The component is and The supporting stiffness of the main bearing between the planetary carrier and the needle gear housing is used for Indicates, along the coordinate axis and The component is and ; Indicates the first The first cycloidal wheel and the first The meshing stiffness between the needle teeth.

[0019] This step includes the following sub-steps: S1.1. Set the assumptions for the equivalent mechanical model.

[0020] In one embodiment, the assumptions are as follows: the sun gear rotates at a constant speed; the meshing of the gear teeth and the support of the bearings are equivalent to the action of a linear spring; the system inertia, the damping force of the contact interface and the friction are ignored; the planetary gears are uniformly distributed and have the same parameters, and the cycloidal gears are distributed with a 180° phase difference and have the same parameters; only the errors, deformations and micro-displacements in the plane where the parts are located are considered.

[0021] S1.2 Establish a global static coordinate system and a moving coordinate system.

[0022] Define the model coordinate system, including a global static coordinate system and a following coordinate system. The global static coordinate system is fixed on the pinwheel housing (base) and serves as the absolute reference for the system's motion. The following coordinate system refers to the local coordinate system fixed to each moving component (such as the sun gear, planet gears, etc.). Specifically, a static coordinate system is established with the center O of the pinwheel housing as the origin. ; This is a moving coordinate system for the sun gear, with its origin coinciding with the center of the sun gear, and its direction parallel to the stationary coordinate system. coincide; This is a planetary gear follower coordinate system, with its origin located at the center of the planetary gear and rotating with it. The number of planetary gears; This is a coordinate system for the cycloidal wheel, where the origin of the coordinate system coincides with the center of the cycloidal wheel and rotates with it. The coordinate axes are... Direction through the center point of the cycloidal wheel and cycloidal wheel node The direction of the vector, the coordinate axis The direction is along the coordinate axis Rotate 90° counterclockwise. These are the serial numbers of the two cycloidal wheels; This is the planet carrier's moving coordinate system, whose origin coincides with the center of the planet carrier, and whose direction is the same as the stationary coordinate system. coincide.

[0023] S1.2 Define the generalized micro-displacement parameters.

[0024] set up This is the input angle of the sun gear; This is the theoretical rotation angle of the planetary gear; Let (the theoretical rotation angle of the planetary carrier); let () The sun gear deforms due to errors and loads. Xianghe A minute displacement or vibration in the direction; For the first The actual rotation angle of each planetary gear ( ) is the first Each planetary gear has rotated a tiny angle relative to its theoretical position, ( ) is the first Due to errors and deformation under load, the planetary gears... Xianghe A minute displacement or vibration in the direction; For the first The actual revolution angle of the cycloidal wheel ( ) is the first The cycloidal wheel rotates a tiny revolution angle relative to its theoretical position; For the first The actual rotation angle of the cycloidal wheel ( ) is the first The actual tiny angle that the cycloidal wheel rotates relative to its theoretical position; For the first Due to errors and deformation under load, the cycloidal wheel... A minute displacement or vibration in direction; This represents the actual angle through which the planetary carrier rotated. ( ) represents the small angle through which the planetary carrier has rotated relative to its theoretical position. The planetary carrier deformed due to errors and loads. Xianghe A minute displacement or vibration in the direction; For the first The phase angle of each planetary gear or crankshaft; For the first The phase angle of each cycloidal wheel.

[0025] S1.3 Construct micro-displacement column vectors to clarify the mechanical characterization method of the multi-degree-of-freedom system (the physically simplified mechanical system of the RV reducer).

[0026] The micro-displacement column vector is a mathematical tool used to describe the motion state of each component in space in an equivalent mechanical model. Based on the physical structure of the "equivalent mechanical model", the "micro-displacement column vector" is defined to characterize the degree of freedom of the system. Finally, the transmission accuracy is obtained by solving this vector.

[0027] Given the input angle of the sun gear In the case of an RV reducer with three crankshafts (applicable to RV reducers with three and two crankshafts; for a model with two crankshafts, simply set the three equations for the extra crankshaft to 0), a 20-degree-of-freedom mechanical analysis model can be established. Each component (including the sun gear, planet gears, crankshaft, cycloidal gear, and planet carrier) is considered for three degrees of freedom in its plane. The sun gear corresponds to two translational degrees of freedom, expressed as (…). Each planetary gear or crankshaft corresponds to 2 translational degrees of freedom and 1 rotational degree of freedom, represented as ( () Each cycloidal wheel corresponds to 1 translational degree of freedom and 2 rotational degrees of freedom, represented as ( )( ), The number represents the cycloidal wheel; the planetary carrier corresponds to 2 translational degrees of freedom and 1 rotational degree of freedom, represented as ( Let the generalized infinitesimal displacement column vector be... for:

[0028] S2. Establish the system of mechanical equations.

[0029] In one embodiment, this step includes the following sub-steps: S21. Based on the error decomposition principle, considering the errors of various components (such as eccentricity in the manufacturing of the sun gear, eccentricity in the crankshaft cam, etc.), construct the deformation coordination equation.

[0030] S211. Construct the deformation coordination equations for the equivalent support spring of the sun gear in the direction of force and the equivalent springs of the planet gear and sun gear pair on the meshing line.

[0031] The deformation compatibility equation for the equivalent support spring of the sun gear in the direction of force is transformed as follows:

[0032]

[0033] ( The deformation of the sun gear's equivalent supporting spring is defined along two coordinate axes, with spring compression being positive and tension being negative. This refers to the situation caused by installation errors. direction and Equivalent error caused by direction.

[0034] Let the first The deformation of the planetary gear and sun gear pair along the equivalent spring meshing line is: The manufacturing eccentricity error of the sun gear and planet gears is ( )and( ), It's a manufacturing eccentricity error in the sun gear. It is the phase error caused by the manufacturing eccentricity of the sun gear. It's a manufacturing eccentricity error in the planetary gears. The manufacturing eccentricity error phase of the planetary gear, such as... Figure 4 As shown; the equivalent error in the gear meshing pair direction caused by manufacturing eccentricity error is denoted as ( ), It is the first The equivalent error of the sun gear on each meshing pair in the direction of the gear meshing pair. It is the first The equivalent error of the planetary gears on a meshing pair in the direction of the gear meshing pair is defined as the direction in which the contact surface is concave due to the error. For the first The angle between the meshing side effect line and the X-axis, The meshing angle of an involute spur gear. These are the number of teeth on the sun gear and planet gears, respectively. It is the distance between the centers of the sun gear and the planet gears. It is the radius of the base circle of the planetary gear.

[0035] The first result caused by the two translational degrees of freedom of the sun gear The deformation of the spring in each gear pair is :

[0036] The third result caused by the three degrees of freedom of the planetary gear The deformation of the spring in each gear pair is :

[0037] No. The deformation compatibility equation of the equivalent springs of the planetary gear and sun gear pair on the meshing line is:

[0038] S212, Constructing the first The crankshaft and the first Deformation compatibility equations for a cycloidal wheel pair along the line of force action.

[0039] Let the first The crankshaft and the first The deformation of the equivalent support spring of each cycloidal wheel pair along the two coordinate axes is ( Let the first... The first cycloidal wheel The positional error of each hole is ( ), as attached Figure 5 As shown, this error is in direction and The equivalent error caused by the direction is ( Let the first... The first crankshaft The eccentricity error of each cam is ( ), as attached Figure 6 As shown, this error is in direction and The equivalent error caused by the direction is ( ); , It is the first The crankshaft and the first The magnitude of the deformation of the equivalent support spring of each cycloidal wheel pair along the two coordinate axes; , It is the first The first cycloidal wheel The magnitude and phase of the positional error of each hole; , It is the first The first crankshaft The magnitude and phase of the eccentricity error of each cam.

[0040] The spring deformation caused by the three degrees of freedom of the cycloidal wheel, along the two coordinate axes, has the following components: );

[0041]

[0042] It is the eccentricity; The spring deformation caused by the three degrees of freedom of the crankshaft, along the two coordinate axes, has the following components: );

[0043]

[0044] Then the first The crankshaft and the first The deformation compatibility equations for the cycloidal wheel pair along the line of force action are as follows:

[0045]

[0046] S213, Constructing the first The first cycloidal wheel and the first The deformation compatibility equation of a needle tooth pair on the meshing line.

[0047] Let the first The first cycloidal wheel and the first The equivalent spring deformation of each needle tooth pair on the meshing line is The equivalent clearance error on the meshing line caused by the cycloidal wheel modification is: The radius error of the needle teeth is The single tooth pitch deviation of the needle tooth groove in the needle tooth housing and radial runout error The equivalent errors generated in the direction of the cycloidal pinwheel meshing line are respectively It can be seen that the equivalent clearance generated by the cycloidal wheel modification is... The expression is:

[0048] In the formula: For the first The angle between each needle tooth and the eccentric direction of the cycloidal wheel; This is the amount of displacement modification; It is an equidistant shaping amount; This is the short-amplitude coefficient of the cycloidal wheel; From the appendix Figure 7 We can obtain the eccentricity. , Indicates the center O of the needle-tooth shell and the first Center of a cycloidal wheel The distance, the pitch of the cycloidal wheel Needle tooth circular pitch , It refers to the number of needle teeth. It refers to the number of teeth on the cycloidal wheel and the radius of the needle teeth. , Indicates the first Needle center The distance between the center O of the needle-tooth shell and the center O.

[0049] The equivalent spring deformation on the meshing line caused by the three degrees of freedom of the cycloidal wheel is: ;

[0050] Refers to the coordinate axes Direction and cycloidal wheel node and the Needle center Angle; This refers to the result of the cycloidal wheel's three degrees of freedom causing the first... The first cycloidal wheel and the first The equivalent spring deformation on the meshing line of each needle tooth; Then the first The first cycloidal wheel and the first The deformation compatibility equation for the pin tooth pair on the meshing line is:

[0051] S214, Constructing the first The deformation compatibility equations of the crankshaft and planetary carrier pair on the line of force action.

[0052] Let the first The equivalent spring deformation of the crankshaft and planetary carrier pair along the line of force action along the two coordinate axes is ( Planetary Carrier The positional error of each bearing hole is denoted as ( ), , The planetary carriage number The positional error and phase of each bearing hole are shown in the attached figure. Figure 8 As shown, this error leads to direction and The equivalent error caused by the direction is ( ); Then the first The deformation compatibility equations for the crankshaft and planetary carrier pair along the line of force action are as follows:

[0053]

[0054] S215. Construct the deformation compatibility equations of the planetary carrier and the needle-tooth shell along the line of force action.

[0055] Let the deformation of the equivalent support spring between the planetary carrier and the pin toothed shell be along the two coordinate axes as ( If the actual installation error of the planetary carrier is ( ), The absolute magnitude of the error. The error is the phase angle relative to the reference position, caused by installation error. direction and The equivalent error caused by the direction is ( ).

[0056] The deformation compatibility equation between the planetary carrier and the needle-tooth shell along the line of force action is:

[0057]

[0058] S22. Corresponding to the meshing stiffness of gear teeth, bearing support stiffness and elastic force, construct physical equations, and perform force analysis on each component to establish force balance equations.

[0059] S221. Analyze the forces acting on the sun gear and establish the force balance equation for the sun gear.

[0060] The Sun Wheel and the First The meshing force between the planetary gears is:

[0061] The force balance equation for the sun gear is:

[0062] , It refers to the equivalent spring force along the x and y directions at the sun gear support bearing.

[0063] S222. Analyze the forces acting on the crankshaft and establish the force balance equations for the crankshaft.

[0064] No. The crankshaft and the first The equivalent spring force between the cycloidal gear pairs, in the x and y directions, is:

[0065]

[0066] No. The components of the force between the crankshaft and the planetary carrier in the x and y directions are:

[0067]

[0068] Then the first The force balance equations for the crankshafts are as follows:

[0069] S223. Analyze the forces acting on the cycloidal wheel and establish the force balance equations for the cycloidal wheel.

[0070] No. The first cycloidal wheel and the first The force between the needle teeth is:

[0071] when At that time, it was assumed that the displacement of the cycloidal wheel was insufficient to overcome the gap between the cycloidal wheel and the needle teeth, meaning that the cycloidal wheel and the needle teeth were not in contact. Therefore, when solving the equations, it could be assumed that... ; Then the first The force balance equations for the cycloidal wheels are:

[0072] S224. Analyze the forces acting on the planetary carrier and establish the force balance equations for the planetary carrier.

[0073] Assuming the planetary carrier acts as the output mechanism, the torque it bears is... The direction of planetary carrier rotation is the negative direction; No. The components of the force between the crankshaft and the planetary carrier in the x and y directions are:

[0074] The force equilibrium equation for the planetary carrier is:

[0075] To verify the effectiveness of the transmission accuracy calculation model constructed through the embodiments of the present invention, in one embodiment, a certain RV reducer was selected as the implementation object. First, the basic structural parameters of this reducer model were determined, as shown in Table 1. These parameters are the basis for constructing the mechanical model.

[0076] Table 1 Basic Parameters of RV Reducer

[0077] Secondly, a set of combinations containing various manufacturing and assembly errors is set as the input conditions for the model, as shown in Table 2.

[0078] Table 2 Error Combinations

[0079] S2. Construct and solve the mechanical equations for the transmission accuracy of the system. Based on the basic parameters of the RV reducer determined in S1 (Table 1) and the set error combination (Table 2), the transmission accuracy calculation model is constructed and solved according to the following steps using the method proposed in this invention.

[0080] S21. Construct an equivalent mechanical model.

[0081] Based on the basic parameters of the RV reducer listed in Table 1, and using the lumped parameter method described in Invention Content S1, an equivalent mechanical model of the reducer with 20 degrees of freedom is established. Specifically, the sun gear and planetary carrier are considered as rigid bodies; the sun gear-planet gear meshing pair, the cycloidal gear-pin gear meshing pair, and each bearing support (sun gear support bearing, crankshaft-cycloidal gear bearing, crankshaft-planetary carrier bearing, planetary carrier main bearing) are all equivalent to linear springs with corresponding stiffness. The composition of the generalized micro-displacement column vector X of this equivalent mechanical model is completely consistent with formula (1).

[0082] S22. Substitute the error parameters to form a closed system of equations.

[0083] The error values ​​in Table 2 are used as known inputs and substituted into the deformation compatibility equations, physical equations, and force balance equations established in step S21 to form a closed nonlinear equation system. The specific substitution process is as follows: Sun gear component: Substitute the actual installation error of the sun gear into formula (2) and formula (3); substitute the manufacturing eccentricity error of the sun gear into formula (6).

[0084] Planetary gear components: Substitute the manufacturing eccentricity error of each planetary gear into formula (6).

[0085] Cycloidal wheel and crankshaft pair: Substitute the crankshaft cam eccentricity error and cycloidal wheel shaft hole position error into the crankshaft-cycloidal wheel pair deformation coordination equation corresponding to S213 in the invention content.

[0086] Cycloidal wheel and pin tooth pair: Substitute the cycloidal wheel profile clearance into formula (7) to calculate the profile equivalent clearance; calculate the pin tooth radius error, pin tooth groove pitch cumulative deviation and radial runout error (see appendix). Figure 10 Substitute the equation for the deformation coordination of the cycloidal wheel-needle tooth pair corresponding to S213 in the invention content.

[0087] Planetary carrier component: Substitute the positional error of the planetary carrier bearing hole into the deformation coordination equation of the crankshaft-planetary carrier pair corresponding to S214; substitute the planetary carrier installation error into the deformation coordination equation of the planetary carrier-pin tooth housing corresponding to S215.

[0088] Physical equations and equilibrium equations: List the physical equations (such as the relationship between meshing force and deformation) and force equilibrium equations for each component.

[0089] S23. Perform numerical solutions.

[0090] Solving all the equations simultaneously forms a closed nonlinear system of equations with the generalized infinitesimal displacement column vector X as the unknown. This embodiment uses the numerical computation software MATLAB to solve this system of equations. Given the input rotation angle of the sun gear... The system varies from 0° to 360°. Using a numerical iterative method, the generalized micro-displacement column vector X of the system in equilibrium state is solved at each input rotation angle position.

[0091] S24. Extract and calculate the transmission error.

[0092] The actual rotational micro-displacement of the planetary carrier is extracted from the generalized micro-displacement column vector X obtained from the solution. According to the definition of transmission error (the difference between the actual rotation angle and the theoretical rotation angle of the output shaft, where the actual rotation angle is the micro-displacement of the actual rotation angle),... By integrating the angle and combining it with the system transmission ratio, the transmission error value of the entire transmission chain can be calculated. By traversing a full revolution of the sun gear, the curve of transmission error as a function of the input rotation angle can be obtained.

[0093] Among them, transmission error Actual rotation angle at the output at each moment With theoretical turning point The difference is the absolute error value; the sign of the error value only indicates whether the output is ahead or behind the input. (Transmission accuracy) The maximum value of transmission error Minimum value minus transmission error , is the relative error value:

[0094]

[0095] S3. Perform results analysis.

[0096] The transmission error curves calculated by this transmission accuracy calculation model are plotted as follows: Figure 11 As shown in the figure. The horizontal axis represents the input shaft rotation angle, and the vertical axis represents the transmission error. Figure 11 The display shows the change in transmission error during one revolution of the planetary carrier at the output end. The transmission error fluctuates around the horizontal axis, and the transmission accuracy is 24 seconds. It can be seen that the method provided by this embodiment of the invention can be used to calculate the transmission accuracy of an RV reducer.

[0097] In one embodiment, a device is provided for constructing a calculation model for the transmission accuracy of an RV reducer that considers component errors, used to implement the method described in the foregoing embodiment. The transmission accuracy calculation model includes an equivalent mechanical model and a set of mechanical equations. The device includes the following modules: The equivalent mechanical model establishment module is used to treat parts with large mass and small deformation in the RV reducer as rigid bodies and parts with large elasticity and negligible mass influence as linear springs based on the lumped parameter method. It establishes coordinate systems and follower coordinate systems, defines generalized micro-displacement parameters, and constructs generalized micro-displacement column vectors. The mechanical equations establishment module is used to establish deformation coordination equations based on the error decomposition principle and combined with errors such as sun gear manufacturing eccentricity and crankshaft cam eccentricity; to construct physical equations by relating gear tooth meshing stiffness, bearing support stiffness and elastic force; and to establish force balance equations for each component. The solver module is used to solve the transmission accuracy calculation model, obtain the solution results, extract the actual micro-displacement of the planetary carrier from the solution results, and calculate the transmission error value of the entire transmission chain by combining the system transmission ratio.

[0098] In one embodiment, a computer device is provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the methods described in the foregoing embodiments.

[0099] In one embodiment, a computer-readable storage medium is provided, the computer-readable storage medium storing a computer program that, when executed by a processor, implements the methods described in the foregoing embodiments.

[0100] The aforementioned device, equipment, and medium can achieve the beneficial effects that the methods described in the foregoing embodiments can achieve. The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined in this invention may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for constructing a calculation model for the transmission accuracy of an RV reducer that considers component errors, characterized in that, Includes the following steps: Construct an equivalent mechanical model, including: based on the lumped parameter method, treating the parts with large mass and small deformation in the RV reducer as rigid bodies, and treating the parts with large elasticity and negligible mass influence as linear springs, establishing a global static coordinate system and a follower coordinate system, defining generalized micro-displacement parameters, and constructing a generalized micro-displacement column vector; Based on the principle of error decomposition and combined with the geometric errors of components, a deformation coordination equation is established; physical equations are constructed by relating gear meshing stiffness, bearing support stiffness and elastic force; and force balance equations are established for each component. By simultaneously solving the generalized micro-displacement column vector, deformation compatibility equation, physical equation, and force balance equation, a transmission accuracy calculation model is obtained. The transmission accuracy of the RV reducer is then calculated using this model.

2. The method for constructing a calculation model for the transmission accuracy of an RV reducer considering component errors according to claim 1, characterized in that, The sun gear and planet carrier are considered as rigid bodies; the sun gear-planet gear meshing pair, cycloidal gear-pin tooth meshing pair, sun gear support bearing, crankshaft-cycloidal gear bearing, crankshaft-planet carrier bearing, and planet carrier main bearing are all equivalent to linear springs with corresponding stiffness.

3. The method for constructing a calculation model for the transmission accuracy of an RV reducer considering component errors according to claim 1, characterized in that, The assumptions of the equivalent mechanical model are as follows: the sun gear rotates at a constant speed; the meshing of the gear teeth and the support of the bearings are equivalent to the action of a linear spring; the system inertia, the damping force of the contact interface and the friction are ignored; the planetary gears are uniformly distributed and have the same parameters, and the cycloidal gears are distributed with a 180° phase difference and have the same parameters; only the errors, deformations and micro-displacements in the plane where the parts are located are considered.

4. The method for constructing a calculation model for the transmission accuracy of an RV reducer considering component errors according to claim 1, characterized in that, The deformation coordination equations include: the deformation coordination equation of the equivalent support spring of the sun gear in the direction of force; the deformation coordination equation of the equivalent spring of the planet gear and sun gear pair on the meshing line; the deformation coordination equation of the crankshaft and cycloidal gear pair on the line of force action; the deformation coordination equation of the cycloidal gear and pin tooth pair on the meshing line; the deformation coordination equation of the crankshaft and planet carrier pair on the line of force action; and the deformation coordination equation of the planet carrier and pin tooth housing on the line of force action.

5. The method for constructing a calculation model for the transmission accuracy of an RV reducer considering component errors according to claim 1, characterized in that, The physical equations include: the meshing force equation between the sun gear and the planet gears, the equivalent spring force equation between the crankshaft and the cycloidal gear pair, the force equation between the crankshaft and the planet carrier, the force equation between the cycloidal gear and the pin tooth, and the force between the crankshaft and the planet carrier.

6. The method for constructing a calculation model for the transmission accuracy of an RV reducer considering component errors according to claim 1, characterized in that, The force balance equations include: the force balance equation for the sun gear, the force balance equation for the crankshaft, the force balance equation for the cycloidal gear, and the force balance equation for the planet carrier.

7. A method for constructing a calculation model for the transmission accuracy of an RV reducer considering component errors, as described in any one of claims 1-6, characterized in that, Solve the transmission accuracy calculation model to obtain the solution results. Extract the actual micro-displacement of the planetary carrier from the solution results and combine it with the system transmission ratio to calculate the transmission error value of the entire transmission chain.

8. A device for constructing a calculation model for the transmission accuracy of an RV reducer that considers component errors, characterized in that, For implementing the method according to any one of claims 1-7, the transmission accuracy calculation model includes an equivalent mechanical model and a set of mechanical equations, and the device includes the following modules: The equivalent mechanical model establishment module is used to treat parts with large mass and small deformation in the RV reducer as rigid bodies and parts with large elasticity and negligible mass influence as linear springs based on the lumped parameter method. It establishes coordinate systems and follower coordinate systems, defines generalized micro-displacement parameters, and constructs generalized micro-displacement column vectors. The mechanical equations establishment module is used to establish deformation coordination equations based on the error decomposition principle and combined with errors such as sun gear manufacturing eccentricity and crankshaft cam eccentricity; and to construct physical equations by relating gear tooth meshing stiffness, bearing support stiffness and elastic force. Establish force balance equations for each component; The solver module is used to solve the transmission accuracy calculation model, obtain the solution results, extract the actual micro-displacement of the planetary carrier from the solution results, and calculate the transmission error value of the entire transmission chain by combining the system transmission ratio.

9. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the method according to any one of claims 1-7.

10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by a processor, it implements the method described in any one of claims 1-7.

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