Microcosmic modification method for large megawatt wind power gear box

Abstract

The invention provides a large megawatt wind power gear box microcosmic modification method, and relates to the field of wind power gear box and gear microcosmic modification, and the method comprises the steps: constructing a planetary gear train rigidity finite element model, and obtaining the average value of the relative deformation of the center of a planetary gear bearing; a planet wheel bearing displacement finite element model is constructed, and radial displacement and tangential displacement of a planet wheel bearing are obtained; calculating the relative deformation of the planet carrier and the displacement of the planet wheel bearing according to the average value of the relative deformation of the center of the planet wheel bearing and the radial displacement and tangential displacement of the planet wheel bearing; a gear torsional deformation simulation calculation model is constructed, planet gear deformation, sun gear torsional deformation and primary internal gear deformation are obtained, and helical angle modification parameters are determined; constructing a planetary gear train gear modification simulation model, inputting the helical angle modification quantity parameter and the tooth top edge modification quantity parameter into the model, and obtaining a tooth direction reverse slope modification quantity parameter; and the machining modification amount is distributed according to the helical angle modification amount parameters through a helical angle modification amount conversion method.

Description

Technical Field

[0001] The present invention relates to the field of wind power gearbox and gear micro-modification, and in particular to a micro-modification method for a large-megawatt wind power gearbox. Background Art

[0002] Gearboxes are the core components of wind turbine equipment, and manufacturers have increasingly higher requirements for the strength verification of their components. The main structural forms of wind turbine gearboxes are planetary structures in series or planetary structures and parallel structures in series. Most planetary structures adopt NGW form. With the increase in gearbox power and the trend of lightweight, the size of the planetary structure and the number of planetary wheels continue to increase, which puts forward higher requirements for the design and analysis of the planetary gear system structure. Therefore, it is of great guiding significance to carry out research on the modification of planetary gears in large megawatt wind turbine gearboxes.

[0003] Gears are the core components of gearboxes. Gear reliability directly determines the reliability of wind turbine operation. The gear tooth contact problem is a highly nonlinear behavior, involving complex engineering backgrounds in dynamics, surface technology, and materials science. Gear modification technology is a key technology for the design and manufacture of high-precision gear transmissions, and domestic and foreign gear companies treat it as their core technology. However, the advantages and disadvantages of gear modification in large-megawatt wind power gearboxes are as follows: the low-speed stages of wind power gearboxes are all planetary stages, and the existing modification design methods do not fully consider the nonlinear contact stiffness of the planetary gears and planetary carriers, resulting in inaccurate helix angle modification and gear eccentricity; the existing modification design does not fully consider the influence of the planetary wheel embryo thickness on the tooth profile modification and helix angle modification; the existing modification design does not consider the influence of the box body load deformation and processing error on the modification of the planetary gear system; when performing symmetrical modification design, if the helix angle modification is large, the tooth surface will be distorted during processing, which will cause uneven contact distribution in the gear tooth profile direction and affect the gear life.

[0004] The present invention is based on the gear meshing principle and combines the finite element analysis method with theoretical analysis and calculation to establish a new method for planetary gear modification design to solve the above problems. Summary of the invention

[0005] According to the above, the existing shaping technology does not consider the technical problems that the inaccurate helix angle shaping amount causes the gear life and does not accurately consider the influence of the planetary carrier deformation and the box load deformation on the planetary gear system shaping, and a large megawatt wind power gearbox micro-shaping method is provided. Based on the principle of gear meshing, the finite element analysis method and theoretical analysis and calculation are combined as means to solve the stability of low-speed and heavy-load gear transmission, ensure the contact state of the large megawatt wind power gearbox gear, and effectively extend the life of the wind power gearbox gear.

[0006] The technical means adopted by the present invention are as follows: A micro-modification method for a large megawatt wind turbine gearbox includes: constructing a finite element model of the planetary gear train stiffness, obtaining the average value of the relative deformation of the planetary gear bearing center at maximum interference, intermediate interference, and minimum interference ; Construct the finite element model of the planetary gear bearing displacement and obtain the radial displacement of the planetary gear bearing and tangential displacement ;according to , , Calculate the relative deformation of the planet carrier and the displacement of the planetary wheel bearing to determine the helix angle modification amount; build a gearbox housing deformation simulation model, calculate the housing bearing seat displacement and convert it into the deformation in the gear meshing plane direction ; Build a planetary gear train gear modification simulation calculation model, input the rated torque, and obtain the planetary gear deformation , sun gear torsional deformation , deformation of the first-stage internal gear , based on the torsional deformation of the gear, the helix angle modification parameters are determined; the helix angle modification parameters and the tooth top trim parameters are input into the model, and the tooth reverse slope modification parameters are obtained according to the stress concentration area of ​​the model contact spot; the helix angle modification parameters are allocated to the processing modification amount through the helix angle modification conversion method.

[0007] Furthermore, the planetary gear train stiffness finite element model includes a planet carrier, a planet pin, a planet wheel bearing and an adjustment ring, wherein a nonlinear contact interference connection is adopted between the planet pin and the planet carrier, and a frictionless forced displacement constraint is applied at the position of the planet carrier bearing seat. The constraint condition retains the rotation direction and axial degree of freedom, and the relative deformation of the planet wheel bearing center at the maximum interference, intermediate interference and minimum interference is read respectively, and the average value of the three relative deformations is calculated. .

[0008] Furthermore, the planetary gear bearing displacement finite element model includes a planetary gear pin, a planetary gear bearing and a planetary gear, wherein the planetary gear and the planetary gear bearing are connected by a rod unit that is only compressed but not tensile, and a gear meshing force is applied at the meshing line position between the planetary gear and the primary internal gear, and between the planetary gear and the sun gear. , fix the planet wheel and the planet carrier at the contact position to obtain the radial displacement of the planet wheel bearing and bearing tangential displacement .

[0009] Furthermore, the planet carrier deformation calculation formula is: ,in, is the gear width, is the displacement center value of the planetary gear bearing, is the relative deformation of the planetary gear bearing center, is the working pressure angle. The calculation formula for the displacement of the planetary gear bearing is: ,in is the gear width, is the displacement center value of the planetary gear bearing, is the radial displacement of the planetary gear bearing, is the tangential displacement of the planetary gear bearing, is the working pressure angle.

[0010] Furthermore, in the gearbox housing deformation simulation model, the torque arm housing is in binding contact with the first-stage internal gear, the first-stage internal gear is in binding contact with the middle housing one, the middle housing one is in binding contact with the second-stage internal gear, the second-stage internal gear is in binding contact with the middle housing two, the middle housing two is in binding contact with the rear housing, the rear housing is in binding contact with the rear housing cover, the bearing spacer rings are in binding contact with the bearing seats of each housing, a distal constraint point is established at the bearing spacer ring position, the rated bearing force under load is applied to this point, the pin hole position applied to the torque arm housing is constrained, the six degrees of freedom are constrained, the relative deformation of the gearbox housing bearing seat is obtained by reading the displacement value of the bearing spacer ring, and the relative deformation is converted into the deformation in the direction of the gear meshing plane; the relative deformation of the gearbox housing bearing seat is converted into the deformation in the direction of the gear meshing plane include:

[0011] in, is the radial relative displacement of the bearing housing, is the relative displacement of the box bearing seat in the direction of gravity, is the engagement angle.

[0012] Furthermore, a planetary gear train gear modification simulation calculation model is constructed, including a planet carrier, a planetary gear pin, a planetary gear, a planetary gear bearing, a sun gear, a planet carrier bearing, and a primary internal gear. In the model, the planet carrier and the sun gear are rotating parts, and the internal gear is a fixed part; the planet carrier and the planet carrier bearing are rigidly connected, and the relative deformation of the wind turbine gearbox housing is calculated, and the planet carrier bearing clearance setting is used for compensation; the planet carrier and the planetary gear pin are connected with contact stiffness, and the contact stiffness is calculated. To set; the planetary gear pin and the planetary gear bearing are rigidly connected, and the planetary gear bearing and the planetary gear are rigidly connected. The radial displacement of the planetary gear bearing is calculated. , bearing tangential displacement , using the planetary gear bearing clearance setting for compensation; the planetary gear is connected to the primary internal gear using the gear meshing stiffness, and the planetary gear is connected to the sun gear using the gear meshing stiffness. The rated power and speed are applied to the end face of the planet carrier, and the power load of the balancing input end is added to the output end of the sun gear spline. The torsional deformation of the sun gear is obtained through the simulation model. , Torsional deformation of the first-stage internal gear , Planetary gear torsional deformation .

[0013] Furthermore, the helix angle modification parameter selection includes: the helix angle modification of the primary internal gear and the planetary gear side is:

[0014] The helix angle modification amount of the sun gear and planet gear side is:

[0015] The selection of gear tip trim parameters includes determining the optimal value of gear trim, i.e. gear deformation , the tooth profile pressure angle modification amount and the tooth profile crowning amount; The calculation formula is as follows:

[0016] in is the usage factor, is the dispersion coefficient, is the gear tangential force, is the tooth width, is the end pressure angle, is the gear mesh stiffness.

[0017] The tooth profile pressure angle modification and tooth profile drum shape follow the principle: pressure angle modification SI = -10um, tooth profile drum shape is selected to ensure that the tooth profile is a convex tooth surface. The tooth profile modification parameter selection includes determining the drum shape and the reverse slope modification; the reverse slope modification is determined according to the stress concentration area of ​​the model contact spot; the drum shape is selected according to the maximum contact stress limit, where the contact stress between the planetary gear and the sun gear is <1200MPa, and the contact stress between the planetary gear and the internal gear is <800MPa.

[0018] Furthermore, the helix angle modification amount conversion method includes: determining the processing amounts of the sun gear, the planetary gear, and the first-stage internal gear that do not cause tooth surface distortion and deformation are respectively , , .

[0019] Helix angle modification of primary internal gear , planetary gear helix angle modification , As the modification amount of double-sided grinding of planetary gears during gear hobbing, the helix angle is the processing helix angle , is the symmetrical modification amount of the planetary gear during gear grinding; is the modification amount of double-sided grinding during gear hobbing; the total modification amount of the sun gear helix angle:

[0020] In the formula is the sun gear tooth width, is the planet gear tooth width; As the modification amount of double-sided grinding of the sun gear during gear hobbing, the helix angle is the processing helix angle , It is the symmetrical modification amount of the sun gear during gear grinding.

[0021] Compared with the prior art, the present invention has the following advantages: 1. Complete simulation calculation model: The model includes the stiffness and connection interaction of components such as bearings, planetary carriers, gears, planetary pins, splines, etc. The modeling process is simple and the simulation calculation is efficient.

[0022] 2. Clear load transfer: The pin connection between the planet carrier and the planetary gear, the bearing connection, the gear meshing, and the constraints of the gear train can accurately express the actual structure and structural connection, and can clearly transfer loads and constraints.

[0023] 3. The simulation results are reliable. The finite element method is used to accurately calculate the torsional deformation of the planet carrier, the deformation of the planet wheel embryo, and the deformation of the box, which solves the problem that the existing methods cannot consider the nonlinear contact deformation of the planet carrier pin and the planet carrier.

[0024] 4. Through Matlab programming, various parameter formulas are integrated into the program. According to the deformation calculation results, the helix angle modification amount can be quickly obtained, which improves the efficiency of gear modification design.

[0025] 5. The gear shaping helix angle conversion method solves the processing distortion problem caused by excessive helix angle modification. By converting the intermediate helix angle, double-sided gear hobbing and grinding can be used for gear processing, which improves processing efficiency and reduces processing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0027] Figure 1 The figure is a flow chart of the method of the present invention.

[0028] Figure 2 This is the finite element model of the planet carrier torsional stiffness.

[0029] Figure 3 Finite element model for planet carrier deformation calculation.

[0030] Figure 4 is the relative deformation of the planetary gear bearing center Computational graph.

[0031] Figure 5 This is a simulation calculation model for the planetary gear bearing displacement.

[0032] Figure 6 Cross-sectional view of the planetary gear bearing displacement simulation model.

[0033] Figure 7 Schematic diagram of the gearbox housing deformation calculation simulation model.

[0034] Figure 8 Calculate the finite element model for the box deformation.

[0035] Fig. 9 A simulation model for planetary gear train gear modification.

[0036] Fig.10 Schematic diagram of the simulation results of the sun gear-planet gear side; (a) is a schematic diagram of the contact spot; (b) is a schematic diagram of the contact stress.

[0037] Fig.11 Schematic diagram of the simulation results of the first-stage internal gear-planetary gear side; (a) is a schematic diagram of the contact spot; (b) is a schematic diagram of the contact stress.

[0038] Fig.12 Schematic diagram of the contact between the planetary gear, the sun gear and the first-stage internal gear; (a) is a schematic diagram of the actual meshing state of the contact side between the sun gear and the planetary gear; (b) is a schematic diagram of the actual contact state between the first-stage internal gear and the planetary gear side.

[0039] Fig.13 Schematic diagram of working pressure angle and end face pressure angle.

[0040] In the figure: 1. Planet carrier; 2. Planet gear pin; 3. Planet gear bearing; 4. Planet gear; 5. Adjusting ring; 6. Planet carrier bearing; 7. Sun gear; 8. Primary internal gear; 9. Torque arm housing; 10. Housing one; 11. Secondary internal gear; 12. Middle housing two; 13. Rear housing; 14. Rear housing cover; 15. Bearing spacer ring. DETAILED DESCRIPTION

[0041] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0042] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0044] like Figure 1-13 As shown, the present invention provides a micro-modification method for a large megawatt wind power gearbox, comprising the following steps: 1. Simulation calculation of torsional deformation of planet carrier: Create a finite element stiffness analysis model of the planet carrier components. The simulation models are all established using solid models. The model includes planet carrier 1, planetary gear pin 2, planetary gear bearing 3 and adjustment ring 5. Define material properties for different components. At the upper and lower wind direction bearing seats of planet carrier 1, select the nodes on the surface for frictionless forced displacement constraints (releasing the rotation direction and axial freedom). A nonlinear contact interference connection is used between the planetary gear pin 2 and the planet carrier 1. Read the relative deformation of the center of the planetary gear bearing at the maximum interference, intermediate interference and minimum interference respectively. .

[0045] 2. Planetary gear overturning simulation calculation: Create a finite element model of the planetary gear 4 component, which includes the planetary gear pin 2, planetary gear bearing 3 and planetary gear 4. The planetary gear 4 and the planetary gear bearing 3 are connected by a rod unit (only compressed but not pulled). Gear meshing force is applied at the meshing line position between the planetary gear 4 and the first-stage internal gear 8, and between the planetary gear 4 and the sun gear 7. , a fixed constraint is applied at the contact position between the planetary gear 4 and the planetary carrier 1, and the radial displacement of the planetary gear bearing 3 is obtained by simulation calculation , bearing tangential displacement .

[0046] 3. Calculation of the helix angle modification of the planetary gear system: Based on the relative deformation of the center of the planetary gear bearing 3 calculated in step 1, the deformation of the planetary carrier 1 is calculated using the formula:

[0047] in, is the gear width, is the displacement center value of the planetary gear bearing, is the relative deformation of the planetary gear bearing center, is the working pressure angle.

[0048] Based on the displacement of the bearing under load conditions calculated in step 2, the bearing displacement is calculated by the formula:

[0049] in is the gear width, is the displacement center value of the planetary gear bearing, is the radial displacement of the planetary gear bearing, is the tangential displacement of the planetary gear bearing, is the working pressure angle.

[0050] 4. Gearbox deformation simulation analysis: Gearbox deformation will cause the center line of the planet carrier 1 to deflect, which is reflected in the radial displacement and axial displacement of the upper and lower wind direction bearing seats, thereby affecting the meshing position of the planetary gear 4. The tooth profile modification is used to compensate for this deviation. By accurately simulating the deformation of the gearbox, it is brought into the planetary gear system gear modification model, and the relative deformation of the wind turbine gearbox is converted into the deformation in the gear meshing plane direction. It is input into the model as bearing clearance. At the same time, the deformation of the housing needs to be considered in the selection of tooth slope and drum shape.

[0051] The box deformation simulation calculation model includes the torque arm box 9, the middle box 1 10, the middle box 2 12, the rear box 13, the first-stage internal gear 8, the second-stage internal gear 11, etc. The rated load is used for calculation. The outer ring of the bearing and the box bearing seat are in binding contact. The displacement value of the bearing spacer ring 15 is read to obtain the relative deformation of the wind turbine gearbox box, and the relative deformation is converted into the deformation in the gear meshing plane direction. ;

[0052] in is the radial relative displacement of the bearing housing, is the relative displacement of the box bearing seat in the direction of gravity, is the engagement angle.

[0053] 5. Establishment of planetary gear modification model: In the planetary gear modification design, the main factor affecting the helix angle modification is the planetary gear bearing displacement , sun gear torsional deformation , Planetary gear deformation , deformation of the first-stage internal gear , Planet carrier torsional deformation , build a planetary gear train gear modification simulation calculation model, input the rated torque, and obtain the planetary gear deformation , sun gear torsional deformation , deformation of the first-stage internal gear , based on the torsional deformation of the gear, determine the helix angle modification parameters.

[0054] A planetary gear train gear modification simulation calculation model is constructed, which includes a flexible planet carrier 1, a planetary gear pin 2, gears, planetary gears, sun gear gears, rigid planetary gears, bearings, etc. In the model, the planet carrier 1 and the sun gear 7 are rotating parts, and the first-stage internal gear 8 is a fixed part. According to the calculated relative deformation of the wind turbine gearbox housing, the clearance setting of the planet carrier bearing 6 is used for compensation; the planet carrier 1 and the planetary gear pin 2 are connected with rigidity, and the calculated value in step 1 is used. To adjust the stiffness of the upper and lower wind direction contact pairs, use the bearing offset calculated in step 2 , As test variables, the planetary gears 4 and the bearing offsets are compensated.

[0055] 6. Helix angle design parameter selection: The helix angle modification of the first-stage internal gear and the planetary gear side is:

[0056] The helix angle modification amount of the sun gear and planet gear side is: .

[0057] 7. Selection of tooth profile modification design parameters: Tooth profile modification includes the amount of tooth tip modification, the amount of tooth profile pressure angle modification and the amount of tooth profile drum shape; the main basis for determining the amount of tooth tip modification is the amount of gear deformation under load conditions, and the optimal value of gear modification is the gear deformation. , the calculation formula is as follows:

[0058] in is the utilization factor, is the dispersion coefficient, is the gear tangential force, is the tooth width, is the end pressure angle, is the gear mesh stiffness.

[0059] The principles followed by the pressure angle modification amount and the tooth profile drum shape amount of the tooth profile are: the pressure angle modification amount SI = -10um, and the tooth profile drum shape amount is selected to ensure that the tooth profile is a convex tooth surface.

[0060] 8. Selection of tooth profile modification design parameters: The tooth profile modification parameters include drum volume and reverse slope. The main factors affecting the selection of reverse slope and drum volume are the relative displacement of the planet carrier 1 bearing and the structural deformation at the support position of the housing, as well as the manufacturing tolerances of some parts. The reverse slope modification volume is determined by the stress concentration phenomenon of the contact stress, and the drum volume is determined by the maximum value of the contact stress. The maximum contact stress between the planetary gear 4 and the sun gear 7 should be less than 1200MPa, and the maximum contact stress between the primary internal gear 8 and the planetary gear 4 should be less than 800MPa.

[0061] 9. Conversion of helix angle modification: The helix angle modification of different meshing sides of the planetary gear system is calculated through step 5. First, through processing tests, it is determined that the processing amount of the sun gear 7, planetary gear 4, and primary internal gear 8 does not cause distortion of the tooth surface. , , ; The helix angle modification amount of the first-stage internal gear is ; The planetary gear helix angle modification amount is , As the modification amount of double-sided grinding of planetary gears during gear hobbing, the helix angle is the processing helix angle , is the symmetrical modification amount of the planetary gear during gear grinding; It is the modification amount of double-sided grinding during gear hobbing.

[0062] Total modification of sun gear helix angle:

[0063] As the modification amount of double-sided grinding of the sun gear during gear hobbing, the helix angle is the processing helix angle , It is the symmetrical modification amount of the sun gear during gear grinding.

[0064] This method ensures that the planetary helix angle modification amount is not restricted, ensures the process feasibility of processing, and reduces the influence of large helix angle modification amount on gear distortion.

[0065] Example 1: The following examples are based on Figure 1 The embodiment is implemented by the process shown in the figure. This embodiment is based on the gear modification design calculation of the planetary gear 4 series structure of a certain megawatt wind power gearbox.

[0066] Figure 2 , Figure 3The finite element model including the planet carrier 1, the planetary gear pin 2, the planetary gear bearing 3 and the adjustment ring 5 is shown. The stiffness calculation is performed using the ANSYS finite element simulation analysis software. The planetary carrier 1 and the planetary gear pin 2 are connected by interference fit, the planetary gear pin 2 and the planetary gear bearing 3 are connected by nonlinear contact interference fit, the planetary gear bearing 3 and the planetary carrier 1 are in friction contact, the planetary gear bearing 3 and the adjustment ring 5 are in friction contact, and the adjustment ring 5 and the planetary carrier 1 are in friction contact. The planetary gear bearing 3 is selected to apply the bearing force, the load is the rated load, and the constraint is applied to the end face of the planetary carrier 1. The deformation curve of the planetary gear pin 2 obtained by simulation calculation is as follows: Figure 4 As shown, the average relative displacement of the center position of the planetary gear bearing 3 at the maximum interference, intermediate interference, and minimum interference is extracted. This value is used to perform contact stiffness correction of the planet carrier 1 and preliminary calculation of the helix angle modification amount of the gear modification model.

[0067] Figure 5 , Figure 6 The finite element model of the planetary gear components is shown. In the model, the planetary gear pin 2, planetary gear bearing 3 and planetary gear 4 are connected with the planetary gear bearing 3 by a rod unit (only under pressure but not tension). The gear meshing force is applied at the meshing line position of the planetary gear 4 and the sun gear 7 / primary internal gear 8 , a fixed constraint is applied at the contact position between the planetary gear 4 and the planetary carrier 1, and then the radial displacement of the planetary gear bearing 3 is obtained. , bearing tangential displacement .

[0068] Figure 7 , Figure 8 What is shown is the deformation simulation calculation model of the wind power gearbox case, the torque arm case 9 is bound and contacted with the first-stage internal gear 8, the first-stage internal gear 8 is bound and contacted with the middle case 10, the middle case 10 is bound and contacted with the second-stage internal gear 11, the second-stage internal gear 11 is bound and contacted with the middle case 2 12, the middle case 2 12 is bound and contacted with the rear case 13, the rear case 13 is bound and contacted with the rear case cover 14, the bearing spacer 15 is bound and contacted with the bearing seat positions of each case, a far-end constraint point is established at the position of the bearing spacer 15, the rated bearing force under load is applied to this point, the pin shaft hole position applied to the torque arm case 9 is constrained, 6 degrees of freedom are constrained, and the relative deformation of the wind power gearbox case is obtained by reading the displacement value of the bearing spacer 15, and the relative displacement is converted into the deformation in the direction of the gear meshing plane.

[0069] Fig. 9The display shows the gear modification simulation calculation model of a large megawatt planetary gear train. The model includes the basic components of planet carrier 1, planetary gear pin 2, planetary gear 4, planetary gear bearing 3, sun gear 7, planetary carrier bearing 6, and primary internal gear 8. The planetary carrier 1 and the planetary carrier bearing 6 are rigidly connected. The deformation of the wind turbine gearbox housing (converted into the deformation in the gear meshing plane direction) is calculated. ) Use the bearing clearance setting to compensate. The planet carrier 1 and the planet gear pin 2 are connected by contact stiffness, and the contact stiffness is calculated. To set, the planetary gear pin 2 and the planetary gear bearing 3 are rigidly connected, and the planetary gear bearing 3 and the planetary gear 4 are rigidly connected. The radial displacement of the planetary gear bearing 3 is calculated. , bearing tangential displacement The bearing clearance setting is used for compensation. The planetary gear 4 is connected to the primary internal gear 8 by the gear meshing stiffness, and the planetary gear 4 is connected to the sun gear 7 by the gear meshing stiffness. The rated power and speed are applied to the end face of the planet carrier 1, and the power load of the balancing input end is added to the output end of the sun gear spline. The corresponding sun gear torsional deformation can be obtained through simulation calculation. , first-stage internal gear torsion variable , Planetary gear torsional deformation The helix angle modification of the planetary gear train gear modification design is shown in Table 1.

[0070] Table 1 Helix angle modification of planetary gear train gear modification design

[0071] The tooth tip trimming amount can be quickly calculated using the formula , the helix angle modification amount and the tooth top edge modification amount are input into the planetary 4 series gear modification simulation calculation model, and the tooth reverse slope modification amount is determined according to the model simulation contact spot stress concentration area. Figure 10-11 .

[0072] Table 2 shows the conversion results of the helix angle modification amount. The large-scale helix angle conversion program developed by Matlab programming can quickly convert the modification amount into the processing helix angle and the finished product helix angle. No matter how large the helix angle modification amount is, the actual processing grinding amount can be controlled. , , Within a reasonable range, no tooth surface distortion occurs during double-sided symmetrical grinding, ensuring that the gear tooth profile directional accuracy meets the use requirements.

[0073] Table 2 Helix angle modification amount conversion results

[0074] Fig.10 , Fig.11Shown is an example simulated contact patch, Fig.12 The traces of the contact spots of the experimental gears are shown. The experimental contact spots are highly consistent with the simulated contact spots, which can illustrate the accuracy of the planet carrier modification design method. This method not only has accurate simulation results and improves the calculation efficiency of the modification design, but also takes the gear processing technology and grinding efficiency into consideration, reducing the gear manufacturing difficulty and processing grinding time.

[0075] Implementation location: This simulation calculation process and method has been applied in the research and development of a megawatt-class wind turbine gearbox.

[0076] Implementation effect: This application aims at the deficiencies of the design calculation method of the planetary gear modification of large-megawatt wind power gearboxes, optimizes the integrity of the simulation calculation model, and includes the stiffness and connection mutual influence of components such as bearings, planet carriers, gears, planetary pins, splines, etc. The modeling process is simple and the simulation calculation is efficient. The load transfer is clear, and the connection between the planet carrier 1 and the planetary gear pin 2, the bearing connection, the gear meshing, and the constraints of the gear train can accurately express the actual structure and structural connection, and can clearly transfer the load and constraints. The simulation results are reliable, and the finite element method is used to accurately calculate the torsional deformation of the planet carrier 1, the deformation of the planetary gear 4 embryo, and the deformation of the box body, which solves the problem that the existing methods cannot consider the nonlinear contact deformation of the planet carrier 1 pin and the planet carrier 1. Through Matlab programming, the various parameter formulas are integrated into the program, and the helical angle modification amount can be quickly obtained according to the deformation calculation results, which improves the efficiency of gear modification design. Through the gear modification helical angle conversion method, the processing distortion deformation problem caused by excessive helical angle modification is solved. Through the conversion of the intermediate helical angle, the gear processing can adopt double-sided hobbing and grinding to improve the processing efficiency. The invention of this application can be extended to gearboxes with NGW structure, and has strong promotional potential. The annual output value of wind power gearboxes in the reducer factory is 2 billion yuan. By applying this technology in the research and development of large-megawatt wind power gearboxes, it can effectively ensure the high reliability of wind power gearboxes, improve product competitiveness, reduce design and production costs, and reduce after-sales service problems. It has great benefits and can produce good economic effects in a sustainable manner.

[0077] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A micro-modification method for a large megawatt wind turbine gearbox, characterized in that: include: Construct a finite element model of the planetary gear train stiffness and obtain the average relative deformation of the planetary gear bearing center at maximum interference, intermediate interference, and minimum interference. ; Construct the finite element model of the planetary gear bearing displacement and obtain the radial displacement of the planetary gear bearing and tangential displacement ;according to , , Calculate the relative deformation of the planet carrier and the displacement of the planetary wheel bearing to determine the helix angle modification amount; build a gearbox housing deformation simulation model, calculate the housing bearing seat displacement and convert it into the deformation in the gear meshing plane direction ; Construct a planetary gear train gear modification simulation model, input the rated torque, and obtain the planetary gear deformation , sun gear torsional deformation , deformation of the first-stage internal gear , based on the torsional deformation of the gear, the helix angle modification parameters are determined; the helix angle modification parameters and the tooth top trim parameters are input into the model, and the tooth reverse slope modification parameters are obtained according to the stress concentration area of ​​the model contact spot; the helix angle modification parameters are allocated to the processing modification amount through the helix angle modification conversion method.

2. A micro-modification method for a large megawatt wind turbine gearbox according to claim 1, characterized in that: The finite element model of the planetary gear train stiffness includes the planet carrier, planetary gear pin, planetary gear bearing and adjustment ring. The planetary gear pin and the planet carrier are connected by nonlinear contact interference, and a frictionless forced displacement constraint is applied to the planet carrier bearing seat. The constraint condition retains the rotation direction and axial freedom. The relative deformation of the planetary gear bearing center at the maximum interference, intermediate interference and minimum interference is read respectively, and the average value of the three relative deformations is calculated. .

3. A micro-modification method for a large megawatt wind turbine gearbox according to claim 2, characterized in that: The finite element model of the planetary gear bearing displacement includes the planetary gear pin, the planetary gear bearing and the planetary gear. The planetary gear and the planetary gear bearing are connected by a rod unit that is only compressed but not tensile. The gear meshing force is applied at the meshing line between the planetary gear and the primary internal gear, and between the planetary gear and the sun gear. , fix the planet wheel and the planet carrier at the contact position to obtain the radial displacement of the planet wheel bearing and bearing tangential displacement .

4. A micro-modification method for a large megawatt wind turbine gearbox according to claim 3, characterized in that: The calculation formula of the planet carrier deformation is: in, is the gear width, is the displacement center value of the planetary gear bearing, is the relative deformation of the planetary gear bearing center, is the working pressure angle; The calculation formula for the displacement of the planetary gear bearing is: in is the gear width, is the displacement center value of the planetary gear bearing, is the radial displacement of the planetary gear bearing, is the tangential displacement of the planetary gear bearing, is the working pressure angle.

5. A micro-modification method for a large megawatt wind turbine gearbox according to claim 4, characterized in that: In the gearbox case deformation simulation model, the torque arm case is in binding contact with the first-stage internal gear, the first-stage internal gear is in binding contact with the middle case one, the middle case one is in binding contact with the second-stage internal gear, the second-stage internal gear is in binding contact with the middle case two, the middle case two is in binding contact with the rear case, the rear case is in binding contact with the rear case cover, the bearing spacer ring is in binding contact with the bearing seat positions of each case, a far-end constraint point is established at the bearing spacer ring position, the rated bearing force under load is applied to this point, the pin hole position applied to the torque arm case is constrained, the six degrees of freedom are constrained, the relative deformation of the gearbox case bearing seat is obtained by reading the displacement value of the bearing spacer ring, and the relative deformation is converted to the deformation in the direction of the gear meshing plane; the relative deformation of the gearbox case bearing seat is converted into the deformation in the direction of the gear meshing plane include: in, is the radial relative displacement of the bearing housing, is the relative displacement of the box bearing seat in the direction of gravity, is the engagement angle.

6. A micro-modification method for a large megawatt wind turbine gearbox according to claim 5, characterized in that: Construct a planetary gear train gear modification simulation calculation model, including the planet carrier, planetary gear pin, planetary gear, planetary gear bearing, sun gear, planet carrier bearing, and primary internal gear. In the model, the planet carrier and sun gear are rotating parts, and the internal gear is a fixed part. The planet carrier and the planet carrier bearing are rigidly connected. According to the calculated relative deformation of the wind turbine gearbox housing, the planet carrier bearing clearance setting is used for compensation. The planet carrier and the planetary gear pin are connected with contact stiffness. The contact stiffness is calculated. To set; the planetary gear pin and the planetary gear bearing are rigidly connected, and the planetary gear bearing and the planetary gear are rigidly connected. The radial displacement of the planetary gear bearing is calculated. , bearing tangential displacement , using the planetary gear bearing clearance setting for compensation; the planetary gear and the primary internal gear are connected by gear meshing stiffness, and the planetary gear and the sun gear are connected by gear meshing stiffness. The rated power and speed are applied to the end face of the planet carrier, and the power load of the balancing input end is added to the output end of the sun gear spline. The torsional deformation of the sun gear is obtained through the simulation model. , Torsional deformation of the first-stage internal gear , Planetary gear torsional deformation .

7. The micro-modification method for a large megawatt wind turbine gearbox according to claim 1, characterized in that: The helix angle modification parameter selection includes: The helix angle modification of the first-stage internal gear and the planetary gear side is: The helix angle modification amount of the sun gear and planet gear side is: The selection of gear tip trim parameters includes determining the optimal value of gear trim, i.e. gear deformation , the modification amount of the tooth profile pressure angle and the tooth profile crowning amount; in The calculation formula is as follows: in is the utilization factor, is the dispersion coefficient, is the gear tangential force, is the tooth width, is the end pressure angle, is the gear meshing stiffness; The principle followed by the pressure angle modification and the crowning of the tooth profile is: the pressure angle modification SI = -10um, and the crowning of the tooth profile is selected to ensure that the tooth profile is a convex tooth surface; The selection of tooth modification parameters includes determining the amount of crowning and the amount of reverse slope modification; the amount of reverse slope modification is determined according to the stress concentration area of ​​the model contact spot; the amount of crowning is selected according to the maximum contact stress limit, where the contact stress between the planetary gear and the sun gear is <1200MPa, and the contact stress between the planetary gear and the internal gear is <800MPa.

8. A micro-modification method for a large megawatt wind turbine gearbox according to claim 7, characterized in that: The helical angle modification amount conversion method comprises: determining the processing amounts of the sun gear, the planetary gear, and the first-stage internal gear that do not cause tooth surface distortion and deformation are respectively , , ; First-stage internal gear helix angle modification , Planetary gear helix angle modification , As the modification amount of double-sided grinding of planetary gears during gear hobbing, the helix angle is the processing helix angle , is the symmetrical modification amount of the planetary gear during gear grinding; It is the modification amount of double-sided grinding during gear hobbing; Total modification of sun gear helix angle: In the formula is the sun gear tooth width, is the planet gear tooth width; As the modification amount of double-sided grinding of the sun gear during gear hobbing, the helix angle is the processing helix angle , It is the symmetrical modification amount of the sun gear during gear grinding.

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