A microscopic modification method for large megawatt wind turbine gearboxes

Abstract

The present invention provides a microscopic modification method for large-megawatt wind power gearboxes, which relates to the fields of wind power gearboxes and gear microscopic modification, and includes: constructing a finite element model of the planetary gear train stiffness to obtain the average value of the relative deformation amount of the planetary gear bearing center; constructing a finite element model of the planetary gear bearing displacement to obtain the radial displacement and tangential displacement of the planetary gear bearing; calculating the relative deformation amount of the planet carrier and the displacement amount of the planetary gear bearing according to the average value of the relative deformation amount of the planetary gear bearing center, the radial displacement and the tangential displacement of the planetary gear bearing; constructing a simulation calculation model of gear torsional deformation to obtain the deformation amount of the planetary gear, the torsional deformation amount of the sun gear, and the deformation amount of the first-stage internal gear, and determining the helix angle modification amount parameter; constructing a simulation model of gear modification for the planetary gear train, inputting the helix angle modification amount parameter and the tooth tip rounding amount parameter into the model to obtain the tooth flank reverse slope modification amount parameter; and distributing the machining modification amount through the helix angle modification amount conversion method for the helix angle modification amount parameter.

Description

Technical Field

[0001] The present invention relates to the fields of wind power gearboxes and gear micro-profile modification, and more particularly, to a micro-profile modification method for large-megawatt wind power gearboxes. Background Art

[0002] As a core component of wind turbine equipment, gearboxes have increasingly high requirements for the strength verification of their components by various manufacturers. The main structural forms of wind power gearboxes are planetary structures in series or a series combination of planetary and parallel structures. Most planetary structures adopt the NGW form. With the increase in gearbox power and the trend of lightweight, the size of the planetary structure and the number of planet gears are continuously increasing, posing higher requirements for the structural design and analysis of the planetary gear train. Therefore, conducting research on the profile modification of planetary gears in large-megawatt wind power gearboxes has important guiding significance.

[0003] Gears are the most core components of gearboxes, and the reliability of gears directly determines the reliability of wind turbine operation. The problem of tooth contact is a highly nonlinear behavior, involving complex engineering backgrounds such as dynamics, surface technology, and materials science. Gear profile modification technology is a key technology for the design and manufacture of high-precision gear transmissions, and gear companies at home and abroad regard it as their core technology. However, the current advantages and disadvantages of gear profile modification for large-megawatt wind power gearboxes are as follows: The low-speed stage of wind power gearboxes is all planetary stages. Existing profile modification design methods do not fully consider the non-linear contact stiffness between planet gears and the planet carrier, resulting in inaccurate helix angle modification amounts and causing gear side loading phenomena; existing profile modification designs do not fully consider the influence of the blank thickness of planet gears on tooth profile modification and helix angle modification; existing profile modification designs do not consider the influence of housing load deformation and machining errors on the profile modification of the planetary gear train; when performing symmetric profile modification design, if the helix angle modification amount is large, it will cause tooth surface distortion during machining, which will lead to uneven contact distribution in the tooth profile direction of the gear and affect the gear life.

[0004] Based on the gear meshing principle, combining finite element analysis methods and theoretical analysis and calculations, the present invention establishes a new method for profile modification design of planetary gears to solve the above problems. Summary of the Invention

[0005] In view of the above technical problems that the existing profile modification technology does not consider the influence of inaccurate helix angle modification amount on gear life and does not accurately consider the influence of planet carrier deformation and housing load deformation on the profile modification of the planetary gear train, a micro-profile modification method for large-megawatt wind power gearboxes is provided. Based on the gear meshing principle, combining finite element analysis methods and theoretical analysis and calculations, it solves the smoothness of low-speed heavy-duty gear transmission, ensures the gear contact state of large-megawatt wind power gearboxes, and effectively extends the gear life of wind power gearboxes.

[0006] The technical means adopted by the present invention are as follows:

[0007] A microscopic modification method for large megawatt wind power gearboxes, comprising: constructing a finite element model of the planetary gear train stiffness, and obtaining the average value of the relative deformation of the planetary gear bearing center at maximum interference, intermediate interference, and minimum interference ; constructing a finite element model of the planetary gear bearing displacement, and obtaining 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 gear bearing, for determining the helix angle modification amount; construct a deformation simulation model of the gearbox housing, calculate the displacement of the housing bearing seat and convert it into the deformation amount in the gear meshing plane direction ; construct a gear modification simulation calculation model of the planetary gear train, input the rated torque, and obtain the deformation amount of the planetary gear 、the torsional deformation amount of the sun gear 、the deformation amount of the first-stage internal gear , based on the gear torsional deformation amount, determine the helix angle modification amount parameter; input the helix angle modification amount parameter and the tooth tip rounding amount parameter into the model, and obtain the tooth flank chamfering modification amount parameter according to the stress concentration area of the contact patch in the model; distribute the machining modification amount through the helix angle modification amount conversion method for the helix angle modification amount parameter

[0008] Furthermore, the finite element model of the planetary gear train stiffness includes a planet carrier, planetary pin shafts, planetary gear bearings, and an adjusting ring. Among them, the planetary pin shafts and the planet carrier are connected by non-linear contact interference, and a frictionless forced displacement constraint is applied at the bearing seat position of the planet carrier. The constraint conditions retain the rotational direction and axial degrees of freedom. Read the relative deformation of the planetary gear bearing center at maximum interference, intermediate interference, and minimum interference respectively, and calculate the average value of the three relative deformations .

[0009] Furthermore, the finite element model of the planetary gear bearing displacement includes planetary pin shafts, planetary gear bearings, and planetary gears. Among them, the planetary gears and the planetary gear bearings are connected by rod elements that are only compressed and not stretched. Gear meshing forces are applied at the meshing lines of the planetary gears and the first-stage internal gears, and the planetary gears and the sun gears , and fixed constraints are applied at the contact positions of the planetary gears and the planet carrier to obtain the radial displacement of the planetary gear bearing and the tangential displacement of the bearing .

[0010] Furthermore, the calculation formula for the deformation amount of the planet carrier is: , where is the gear width, is the central value of the planetary gear bearing displacement, 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 as follows: , where is the gear width, is the central value of the displacement 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.

[0011] Furthermore, in the deformation simulation model of the gearbox housing, the torque arm housing is in bonded contact with the first-stage internal gear, the first-stage internal gear is in bonded contact with the first middle housing, the first middle housing is in bonded contact with the second-stage internal gear, the second-stage internal gear is in bonded contact with the second middle housing, the second middle housing is in bonded contact with the rear housing, the rear housing is in bonded contact with the rear housing cover, and the bearing spacer rings are in bonded contact with the bearing seats of each housing. A remote constraint point is established at the position of the bearing spacer ring, and the bearing force under the rated load is applied at this point. The constraint is applied to the pin shaft hole position of the torque arm housing, restricting the six-degree-of-freedom in all directions. The relative deformation of the bearing seat of the gearbox housing is obtained by reading the displacement value of the bearing spacer ring, and the relative deformation is converted into the deformation in the gear meshing plane direction; the relative deformation of the bearing seat of the gearbox housing is converted into the deformation in the gear meshing plane direction including:

[0012]

[0013] where, is the relative radial displacement of the bearing seat housing, is the relative displacement in the gravity direction of the housing bearing seat, is the meshing angle.

[0014] Furthermore, a gear modification simulation calculation model of the planetary gear train is constructed, including a planet carrier, a planetary gear pin shaft, planetary gears, planetary gear bearings, a sun gear, a planet carrier bearing, and a first-stage internal gear. In the model, the planet carrier and the sun gear are rotating parts, and the internal gear is a fixed part; among them, the planet carrier and the planet carrier bearing are rigidly connected, and according to the relative deformation of the wind power gearbox housing obtained by calculation, compensation is carried out by setting the clearance of the planet carrier bearing; the planet carrier and the planetary gear pin shaft are connected with contact stiffness, and the contact stiffness is set through the calculated ; the planetary gear pin shaft and the planetary gear bearing are rigidly connected, the planetary gear bearing and the planetary gear are rigidly connected, and through the calculated radial displacement of the planetary gear bearing and the tangential displacement , compensation is carried out by setting the clearance of the planetary gear bearing; the planetary gear and the first-stage internal gear are connected by the gear meshing stiffness, and the planetary gear and the sun gear are connected by the gear meshing stiffness. The rated power and speed are applied to the end face of the planet carrier, and the power load at the input end is balanced at the spline output end of the sun gear. The torsional deformation of the sun gear is obtained through the simulation model , the torsional deformation of the first-stage internal gear , the torsional deformation of the planetary gear .

[0015] Furthermore, the selection of the helix angle modification amount parameters includes: the helix angle modification amounts on the side of the first-stage internal gear and the planetary gear are:

[0016]

[0017] The helix angle modification amounts on the side of the sun gear and the planetary gear are:

[0018]

[0019] The selection of the tip relief amount parameters includes determining the optimal value of the gear relief amount, i.e., the gear deformation amount , the profile pressure angle modification amount, and the profile crowning amount; among them The calculation formulas are as follows:

[0020]

[0021] Among them is the service factor, is the dispersion factor, is the tangential force of the gear, is the face width, is the transverse pressure angle, is the gear meshing stiffness.

[0022] The principles followed by the profile pressure angle modification amount and the profile crowning amount are: the profile pressure angle modification amount SI = -10um, and the profile crowning amount is selected to ensure that the tooth profile is a convex tooth surface. The selection of the helix modification parameters includes determining the crowning amount and the taper modification amount; the taper modification amount is determined according to the stress concentration area of the contact patch in the model; the crowning amount is selected according to the maximum limit of the contact stress, where the contact stress between the planetary gear and the sun gear < 1200 MPa, and the contact stress between the planetary gear and the internal gear < 800 MPa.

[0023] Furthermore, the method for converting the helix angle modification amount includes: determining that the machining amounts of the sun gear, the planetary gear, and the first-stage internal gear that do not cause tooth surface distortion are respectively , , .

[0024] The helix angle modification amount of the first-stage internal gear , the helix angle modification amount of the planetary gear , As the modification amount for double-sided grinding during hobbing of the planet gear, the helix angle is the machining helix angle , is the symmetric modification amount of the planet gear during gear grinding; where is the modification amount for double-sided grinding during hobbing; Total modification amount of the helix angle of the sun gear:

[0025]

[0026] In the formula is the tooth width of the sun gear, is the tooth width of the planet gear; As the modification amount for double-sided grinding during hobbing of the sun gear, the helix angle is the machining helix angle , is the symmetric modification amount of the sun gear during gear grinding.

[0027] Compared with the prior art, the present invention has the following advantages:

[0028] 1. Complete simulation calculation model: The model includes the stiffness of components such as bearings, planet carriers, gears, planet pin shafts, and splines and the mutual influence of connections. The modeling process is simple and the simulation calculation is efficient.

[0029] 2. Clear load transfer: The connection between the planet carrier and the planet pin shaft, bearing connection, gear meshing, and constraints of the gear train can accurately represent the actual structure and structural connections, and can clearly transfer loads and constraints.

[0030] 3. Reliable simulation results. By using finite element means, the torsional deformation of the planet carrier, the deformation of the planet gear blank, and the deformation of the housing are accurately calculated, solving the problem that the prior art cannot consider the non-linear contact deformation between the planet pin shaft and the planet carrier.

[0031] 4. Through Matlab programming, various parameter formulas are integrated into the program, and the helix angle modification amount can be quickly obtained according to the deformation calculation results, improving the gear modification design efficiency.

[0032] 5. Through the gear modification helix angle conversion method, the problem of machining twist deformation caused by excessive helix angle modification amount is solved. Through the conversion of the intermediate helix angle, double-sided hobbing and gear grinding can be used for gear machining, improving the machining efficiency and reducing the machining cost. Description of the Drawings

[0033] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0034] Figure 1 It is the flowchart of the method of the present invention.

[0035] Figure 2 It is the finite element model of the torsional stiffness of the planet carrier.

[0036] Figure 3 It is the finite element model for calculating the deformation of the planet carrier.

[0037] Figure 4 It is the relative deformation of the center of the planet wheel bearing Calculation diagram.

[0038] Figure 5 It is the simulation calculation model of the displacement of the planet wheel bearing.

[0039] Figure 6 It is the sectional view of the simulation calculation model of the displacement of the planet wheel bearing.

[0040] Figure 7 It is the schematic diagram of the simulation model for calculating the deformation of the gearbox housing.

[0041] Figure 8 It is the finite element model for calculating the deformation of the housing.

[0042] Figure 9 It is the simulation model for gear modification of the planetary gear train.

[0043] Figure 10 It is the schematic diagram of the simulation results of the sun gear - planet gear side; among which (a) is the schematic diagram of the contact patch; (b) is the schematic diagram of the contact stress.

[0044] Figure 11 It is the schematic diagram of the simulation results of the first - stage internal gear - planet gear side; among which (a) is the schematic diagram of the contact patch; (b) is the schematic diagram of the contact stress.

[0045] Figure 12 It is the schematic diagram of the contact between the planet gear and the sun gear and the first - stage internal gear; among which (a) is the schematic diagram of the actual meshing state on the contact side of the sun gear and the planet gear; (b) is the schematic diagram of the actual contact state on the side of the first - stage internal gear and the planet gear.

[0046] Figure 13 It is the schematic diagram of the working pressure angle and the transverse pressure angle.

[0047] In the figure: 1. Planet carrier; 2. Planet wheel pin shaft; 3. Planet wheel bearing; 4. Planet wheel; 5. Adjusting ring; 6. Planet carrier bearing; 7. Sun gear; 8. First-stage internal gear; 9. Torsion arm box body; 10. First box body; 11. Second-stage internal gear; 12. Second middle box body; 13. Rear box body; 14. Rear box body cover; 15. Bearing spacer ring. Detailed implementation manners

[0048] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments may 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.

[0049] To make the objectives, 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 with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are only a part rather than all of the embodiments of the present invention. The description of at least one exemplary embodiment below is actually only illustrative and in no way limits the present invention and its application or use. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present invention without creative efforts shall fall within the protection scope of the present invention.

[0050] It should be noted that the terms used herein are only for describing the specific implementation manners and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless otherwise clearly specified in the context, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of the features, steps, operations, devices, components and / or their combinations.

[0051] As Figures 1-13 shown, the present invention provides a microscopic modification method for a large-megawatt wind power gearbox, including the following steps:

[0052] 1. Simulation calculation of the torsional deformation of the planet carrier: Create a finite element stiffness analysis model of the planet carrier component. The simulation models are all established using solid models. The models include the planet carrier 1, the planet wheel pin shaft 2, the planet wheel bearing 3, and the adjusting ring 5. Define the material properties for different components. At the positions of the upper and lower windward bearing seats of the planet carrier 1, select the surface nodes for frictionless forced displacement constraints (release the rotational direction and axial degrees of freedom). Adopt a non-linear contact interference connection between the planet wheel pin shaft 2 and the planet carrier 1, and respectively read the relative deformation amounts of the center of the planet wheel bearing at the maximum interference, the intermediate interference, and the minimum interference. .

[0053] 2. Overturning simulation calculation of the planetary gear component: Create a finite element model of the planetary gear 4 component, which includes the planetary gear pin 2, the planetary gear bearing 3, and the planetary gear 4. The planetary gear 4 and the planetary gear bearing 3 are connected by rod elements (only compressed and not tensioned). Apply the gear meshing force at the meshing line positions between the planetary gear 4 and the first-stage internal gear 8, and between the planetary gear 4 and the sun gear 7. Apply fixed constraints at the contact position between the planetary gear 4 and the planet carrier 1, and obtain the radial displacement of the planetary gear bearing 3 through simulation calculation. The tangential displacement of the bearing .

[0054] 3. Calculation of the helix angle modification amount of the planetary gear train: Based on the relative deformation amount of the center of the planetary gear bearing 3 calculated in step 1, calculate the deformation amount of the planet carrier 1 through the formula:

[0055]

[0056] Among them, is the gear width, is the center value of the planetary gear bearing displacement, is the relative deformation amount of the planetary gear bearing center, is the working pressure angle.

[0057] Calculate the bearing displacement through the formula based on the displacement of the bearing under the load condition calculated in step 2:

[0058]

[0059] Among them is the gear width, is the center value of the planetary gear bearing displacement, is the radial displacement of the planetary gear bearing, is the tangential displacement of the planetary gear bearing, is the working pressure angle.

[0060] 4. Simulation analysis of the deformation of the gearbox housing: The deformation of the gearbox housing will cause the center line of the planet carrier 1 to deflect, which is reflected in the radial displacement and axial displacement at the upper and lower windward bearing seat positions, thus affecting the meshing position of the planetary gear 4. Use tooth modification to compensate for this deviation. Through accurate simulation of the housing deformation, bring it into the tooth modification model of the planetary gear train, and convert the relative deformation amount of the wind power gearbox housing into the deformation amount in the gear meshing plane direction as the bearing clearance input into the model. At the same time, the deformation amount of the housing needs to be considered in the selection of the tooth slope and crown amount.

[0061] In the simulation calculation model of the box body deformation, it includes the torque arm box body 9, the middle box body 10, the middle box body 12, the rear box body 13, the first-stage internal gear 8, the second-stage internal gear 11, etc. The calculation is carried out using the rated load. The outer ring of the bearing and the bearing seat of the box body adopt bonded contact. The displacement value of the bearing spacer ring 15 is read to obtain the relative deformation amount of the wind power gearbox box body, and the relative deformation amount is converted into the deformation amount in the direction of the gear meshing plane. ;

[0062]

[0063] Among them is the relative radial displacement of the bearing seat box body, is the relative displacement of the bearing seat of the box body in the gravity direction, is the meshing angle.

[0064] 5. Establishment of the gear modification model for the planetary gear train: In the modification design of the planetary gear train, the main factors affecting the helix angle modification are the displacement of the planetary gear bearing , the torsional deformation amount of the sun gear , the deformation amount of the planetary gear , the deformation amount of the first-stage internal gear , the torsional deformation amount of the planet carrier . A simulation calculation model for the gear modification of the planetary gear train is constructed. The rated torque is input to obtain the deformation amount of the planetary gear , the torsional deformation amount of the sun gear , the deformation amount of the first-stage internal gear . Based on the torsional deformation amount of the gear, the helix angle modification amount parameter is determined.

[0065] Construct a simulation calculation model for the gear modification of the planetary gear train, which includes a flexible planet carrier 1, a planetary gear pin 2, gears, planetary gear teeth, sun gear teeth, a rigid planetary gear, 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 relative deformation amount of the wind power gearbox box body obtained by calculation, the clearance of the planet carrier bearing 6 is set for compensation; among them, the planet carrier 1 and the planetary gear pin 2 are connected with stiffness, and the calculated in step 1 is used to adjust the stiffness value of the upwind and downwind contact pairs, and the bearing offset amounts , calculated in step 2 are used as inspection quantities to compensate for the planetary gear 4 and the bearing offset.

[0066] 6. Selection of helix angle design parameters:

[0067] The helix angle modification amounts for the first-stage internal gear and the planetary gear side are:

[0068]

[0069] The modification amounts of the helix angles on the sun gear and planet gear sides are as follows:

[0070] .

[0071] 7. Selection of tooth profile modification design parameters: Tooth profile modification includes the tip rounding amount, the tooth profile pressure angle modification amount, and the tooth profile crowning amount; The main basis for determining the tip rounding amount is the deformation amount of the gear under load, and the optimal value of the gear rounding amount is the gear deformation amount , and the calculation formula is as follows:

[0072]

[0073] Where is the service factor, is the dispersion factor, is the tangential force of the gear, is the tooth width, is the transverse pressure angle, is the gear mesh stiffness.

[0074] The principles followed by the tooth profile pressure angle modification amount and the tooth profile crowning amount are: the pressure angle modification amount SI = -10 μm, and the tooth profile crowning amount is selected to ensure that the tooth profile is a convex tooth surface.

[0075] 8. Selection of tooth direction modification design parameters: Tooth direction modification parameters include the crowning amount and the taper; The relative displacement of the bearings of the planet carrier 1, the structural deformation at the box support position, and the manufacturing tolerances of some components mainly affect the selection of the taper and the crowning amount. The taper modification amount is determined by the stress concentration phenomenon of the contact stress, and the crowning amount is determined by the maximum value of the contact stress. The maximum value of the contact stress between the planet gear 4 and the sun gear 7 should be less than 1200 MPa, and the maximum value of the contact stress between the first-stage internal gear 8 and the planet gear 4 should be less than 800 MPa.

[0076] 9. Conversion of the helix angle modification amount: The helix angle modification amounts on different meshing sides of the planetary gear train are calculated through step 5. First, determine through machining tests the machining amounts , , ;

[0077] The helix angle modification amount of the first-stage internal gear is ;

[0078] The helix angle modification amount of the planet gear is , as the modification amount for double-sided grinding during hobbing of the planet gear, the helix angle is the machining helix angle , is the symmetrical modification amount of the planet gear during gear grinding; where is the modification amount for double-sided grinding during hobbing.

[0079] Total modification amount of sun gear helix angle:

[0080]

[0081] As the modification amount for double-sided grinding during hobbing of the sun gear, the helix angle is the machining helix angle , is the symmetric modification amount of the sun gear during gear grinding.

[0082] By this method, it not only ensures that the modification amount of the planetary stage helix angle is not restricted, but also ensures the process feasibility of machining, and reduces the influence of the large helix angle modification amount on the gear distortion.

[0083] Example 1: The following example is implemented according to the process shown in Figure 1 , and this example is based on a certain MW wind power gearbox for gear modification design and calculation of the planetary gear 4-series structure.

[0084] Figure 2 , Figure 3 shows the finite element model including the planet carrier 1, the planetary pin 2, the planetary bearing 3 and the adjusting ring 5. The stiffness calculation is carried out using the ANSYS finite element simulation analysis software. The planet carrier 1 and the planetary pin 2 are connected by interference fit. There is a non-linear contact interference connection between the planetary pin 2 and the planetary bearing 3. There is a frictional contact between the planetary bearing 3 and the planet carrier 1, a frictional contact between the planetary bearing 3 and the adjusting ring 5, and a frictional contact between the adjusting ring 5 and the planet carrier 1. The planetary bearing 3 is selected to apply the bearing force, and the load is the rated load. The constraint is applied to the end face of the planet carrier 1. The deformation curve of the planetary pin 2 is obtained through simulation calculation as shown in Figure 4 , and the average relative displacement values at the center position of the planetary bearing 3 at the maximum interference, the intermediate interference, and the minimum interference are extracted , and the contact stiffness of the planet carrier 1 of the gear modification model and the initial calculation of the helix angle modification amount are carried out through this value.

[0085] Figure 5 , Figure 6 shows the finite element model of the planetary gear components. In the model, there are the planetary pin 2, the planetary bearing 3 and the planetary gear 4. The planetary gear 4 is connected to the planetary bearing 3 by a rod element (only compressed and not tensile). The gear meshing force is applied at the meshing line position of the planetary gear 4 and the sun gear 7 / the first-stage internal gear 8 , and a fixed constraint is carried out at the contact position between the planetary gear 4 and the planet carrier 1, and then the radial displacement and the tangential displacement of the bearing of the planetary bearing 3 are obtained.

[0086] Figure 7 ,Figure 8 Shown is the simulation calculation model of the deformation of the wind power gearbox housing. The torque arm housing 9 is in bonded contact with the first-stage internal gear 8. The first-stage internal gear 8 is in bonded contact with the first middle housing 10, the first middle housing 10 is in bonded contact with the second-stage internal gear 11, the second-stage internal gear 11 is in bonded contact with the second middle housing 12, the second middle housing 12 is in bonded contact with the rear housing 13, the rear housing 13 is in bonded contact with the rear housing cover 14. The bearing spacer ring 15 is in bonded contact with the bearing seat positions of each housing. A remote constraint point is established at the position of the bearing spacer ring 15, and the bearing force under the rated load is applied at this point. The constraint is applied to the pin shaft hole position of the torque arm housing 9, restricting the six-direction degrees of freedom. The relative deformation of the wind power gearbox housing is obtained by reading the displacement value of the bearing spacer ring 15, and the relative displacement is converted into the deformation in the gear meshing plane direction.

[0087] Figure 9 Shown is the simulation calculation model of the gear modification of the large MW planetary gear train. The basic components included in the model are the planet carrier 1, the planet wheel pin shaft 2, the planet wheel 4, the planet wheel bearing 3, the sun gear 7, the planet carrier bearing 6, and the first-stage internal gear 8. Among them, the planet carrier 1 and the planet carrier bearing 6 are rigidly connected. The calculated deformation of the wind power gearbox housing (converted into the deformation in the gear meshing plane direction ) is compensated by setting the bearing clearance. The planet carrier 1 and the planet wheel pin shaft 2 are connected with contact stiffness, and the contact stiffness is set through the calculated. The planet wheel pin shaft 2 and the planet wheel bearing 3 are rigidly connected, and the planet wheel bearing 3 and the planet wheel 4 are rigidly connected. The radial displacement of the planet wheel bearing 3 and the tangential displacement of the bearing are compensated by setting the bearing clearance. The planet wheel 4 and the first-stage internal gear 8 are connected with gear meshing stiffness, and the planet wheel 4 and the sun gear 7 are connected with gear meshing stiffness. The rated power and speed are applied to the end face of the planet carrier 1, and a power load balancing the input power is added to the spline output end of the sun gear. Through simulation calculation, the corresponding torsional deformation of the sun gear , the torsional deformation of the first-stage internal gear , and the torsional deformation of the planet wheel can be obtained. The helix angle modification amount of the gear modification design of the planetary gear train is shown in Table 1.

[0088] Table 1 Helix angle modification amount of gear modification design of planetary gear train

[0089]

[0090] The tooth tip rounding amount can be quickly calculated through the formula , input the helix angle modification amount and the tip relief amount into the planetary gear train gear modification simulation calculation model. According to the stress concentration area of the contact patch in the model simulation, determine the modification amount of the tooth flank slope. The modified simulation contact patch is as Figures 10-11 .

[0091] Table 2 shows the conversion results of the helix angle modification amount. By developing a large megawatt helix angle conversion program through Matlab programming, the modification amount can be quickly converted into the machining helix angle and the finished helix angle. Regardless of the size of the helix angle modification amount, the actual machining grinding amount can be controlled 、 、 within a reasonable range, and no tooth surface distortion occurs during double-sided symmetrical grinding, ensuring that the tooth profile direction accuracy of the gear meets the usage requirements.

[0092] Table 2 Conversion Results of Helix Angle Modification Amount

[0093]

[0094] Figure 10 , Figure 11 shows the simulation contact patch of the embodiment. Figure 12 shows the contact patch trace of the test gear in the embodiment. The test contact patch is highly consistent with the simulation contact patch, which can illustrate the accuracy of the planet carrier modification design method. This method not only has accurate simulation results, improves the calculation efficiency of the modification design, but also takes into account the gear processing manufacturability and grinding efficiency, reducing the gear manufacturing difficulty and machining grinding time.

[0095] Implementation Location: This simulation calculation process and method have been applied in the research and development process of a certain megawatt-class wind power gearbox.

[0096] Implementation effect: In view of the deficiencies in the modification design calculation method of the planetary gear train of large-megawatt wind turbine gearboxes in this application, the integrity of the simulation calculation model is optimized. The model includes the stiffness of components such as bearings, planet carriers, gears, planetary pin shafts, and splines and the mutual influence of connections. The modeling process is simple and the simulation calculation is efficient. The load transfer is clear. The connection between the planet carrier 1 and the planetary pin shaft 2, the bearing connection, the gear meshing, and the constraints of the gear train can accurately represent the actual structure and structural connections, and can clearly transfer the load and constraints. The simulation results are reliable. The torsional deformation of the planet carrier 1, the embryo deformation of the planetary gear 4, and the deformation of the box body are accurately calculated by using finite element means, solving the problem that the existing means cannot consider the pin shaft of the planet carrier 1 and the non-linear contact deformation of the planet carrier 1. Through Matlab programming, each parameter formula is integrated into the program, and the helix angle modification amount can be quickly obtained according to the deformation calculation result, improving the gear modification design efficiency. Through the gear modification helix angle conversion method, the machining twist deformation problem caused by too large helix angle modification amount is solved. By converting the intermediate helix angle, double-sided hobbing and gear grinding can be used for gear machining, improving the machining efficiency. The invention of this application can be extended and applied to gearboxes adopting the NGW structure form, with extremely strong popularization. The annual output value of the wind turbine gearbox of the reducer factory is 2 billion yuan. By applying this technology in the research and development process of large-megawatt wind turbine gearboxes, the high-reliability operation of the wind turbine gearbox can be effectively guaranteed, which is of great benefit in improving product competitiveness, reducing design and production costs, and reducing after-sales service problems, and can continuously produce good economic effects.

[0097] 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 them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions 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 according to and Calculate the displacement of the planetary gear bearing to determine the amount of helix angle modification; 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, and calculate the gear meshing plane deformation according to the calculated gear meshing plane deformation. , use the planetary carrier bearing clearance setting to compensate the planetary gear train gear modification simulation calculation model, input the rated torque, and obtain the planetary gear torsional deformation , sun gear torsional deformation , deformation of the first-stage internal gear , based on the planetary gear deformation , sun gear torsional deformation , Torsional deformation of the first-stage internal gear , determine the helix angle modification parameter; input the helix angle modification parameter and the tooth top trim parameter into the planetary gear train gear modification simulation calculation model, and obtain the tooth reverse slope modification parameter according to the contact spot stress concentration area of ​​the planetary gear train gear modification simulation calculation model; allocate the processing modification amount to the helix angle modification parameter through the helix angle modification conversion method; 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; 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 tooth modification parameter selection 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; 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, 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; Used as the modification amount for double-sided grinding of the sun gear during gear hobbing.

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 1, 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.

5. A micro-modification method for a large megawatt wind turbine gearbox according to claim 4, 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; the planet carrier and the planet gear pin are contact stiffness connected. The contact stiffness is calculated by 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 first-stage 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 planetary gear train gear modification simulation calculation model. , Torsional deformation of the first-stage internal gear , Planetary gear torsional deformation .

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