Method for hoisting a wind turbine drive train

Abstract

The present disclosure relates to the field of wind power generation technology, and provides a hoisting method of a transmission chain of a wind turbine generator. The method comprises the following steps: embedding a first number of first double-headed studs in threaded holes of a main bearing mounting surface of a front frame of the wind turbine generator; installing a lifting tool in a preset bolt hole on a main shaft flange of the transmission chain; taking the preset bolt hole as a lifting point, hoisting the transmission chain by the lifting tool, and adjusting the hoisting to make the hoisting angle a first preset angle; when the hoisting angle is the first preset angle, hoisting the transmission chain to above a nacelle of the wind turbine generator by the lifting tool, and performing a positioning operation on the transmission chain to make the first double-headed studs embedded in the front frame pass through a main shaft bearing seat of the transmission chain, and make a torsion arm of a gear box of the transmission chain sit on a lower base of an elastic support assembly of the gear box; after the transmission chain is completely positioned, embedding other first double-headed studs in other threaded holes of the main bearing mounting surface. The present scheme can improve the positioning efficiency of the transmission chain.

Description

Technical Field

[0001] This disclosure relates to the field of wind power generation technology, and more specifically, to a method for hoisting a wind turbine drive chain. Background Technology

[0002] As the wind power industry develops towards larger capacity and higher power, the overall weight and structural dimensions of the wind turbine's drivetrain (integrating components such as the main shaft, main bearing, gearbox, and generator) continue to increase. Meanwhile, the installation space inside the nacelle is relatively small, making the high-altitude hoisting and alignment of the drivetrain one of the most difficult and risky steps in the wind turbine assembly process. Hoisting efficiency and installation accuracy directly affect the overall assembly cycle and operational reliability.

[0003] In related technologies, all double-ended studs on the main bearing mounting surface of the front frame are pre-installed before hoisting. Then, the entire drive chain is hoisted to the top of the nacelle, and with manual assistance, all double-ended studs are simultaneously inserted into the mounting holes of the main bearing housing, finally completing the placement and tightening. However, the large number and exposed length of the double-ended studs on the main bearing mounting surface make alignment during hoisting extremely difficult. Even slight deviations in the drive chain's posture can cause the studs to rub against the bearing housing hole wall, resulting in thread damage and hole wall scratches, affecting assembly accuracy and connection reliability. Furthermore, in these technologies, the hoisting angle is not actively calibrated and precisely controlled during the ground hoisting phase. The initial hoisting posture relies on the experience of the construction personnel, leading to repeated adjustments of the drive chain's posture at high altitude to match the stud positions after hoisting. This results in prolonged operation time and affects the efficiency of the drive chain's hoisting and placement.

[0004] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0005] The purpose of this disclosure is to provide a method for hoisting a wind turbine drive chain, thereby improving the installation efficiency of the wind turbine drive chain to at least a certain extent.

[0006] Other features and advantages of this disclosure will become apparent from the following detailed description, or may be learned in part from practice of this disclosure.

[0007] According to one aspect of this disclosure, a method for hoisting a wind turbine drivetrain is provided, comprising: pre-embedding a first number of first double-ended studs in threaded holes on the main bearing mounting surface of the wind turbine front frame, wherein the first number is less than a second number of threaded holes on the main bearing mounting surface of the wind turbine, and the first double-ended studs are used for installation and positioning of the drivetrain; installing a lifting device in preset bolt holes on the main shaft flange of the drivetrain; using the preset bolt holes on the main shaft flange as lifting points, hoisting the drivetrain with the lifting device, and adjusting the hoisting angle to a first preset angle. The lifting angle is the angle between the transmission chain and the horizontal direction. When the lifting angle is the first preset angle, the transmission chain is lifted to the top of the wind turbine nacelle by the lifting device, and the transmission chain is positioned so that the first double-ended stud pre-embedded on the front frame passes through the main bearing seat of the transmission chain, and the torque arm of the gearbox of the transmission chain sits on the lower base of the elastic support assembly of the gearbox. After the transmission chain is fully positioned, other first double-ended studs are pre-embedded in other threaded holes in the main bearing mounting surface of the wind turbine front frame.

[0008] As can be seen from the above technical solution, the wind turbine drive train installation method in the exemplary embodiment of this disclosure has at least the following advantages and positive effects: In some embodiments of the present disclosure, the technical solutions provided include, on the one hand, pre-embedding a small number of studs, and then pre-embedding other studs after the transmission chain is in place, which facilitates rapid installation and alignment during the placement of the transmission chain and improves the placement efficiency of the transmission chain; on the other hand, the present disclosure adjusts the lifting angle during the lifting stage of the transmission chain, reducing repeated high-altitude posture adjustments after the transmission chain is lifted, and improving lifting safety.

[0009] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description

[0010] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure. It is obvious that the drawings described below are merely some embodiments of this disclosure, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0011] Figure 1 This diagram illustrates a process flow of a method for hoisting a wind turbine drive train according to an exemplary embodiment of the present disclosure. Figure 2 This diagram illustrates a flowchart of a method for determining a preset bolt hole according to an exemplary embodiment of the present disclosure. Figure 3 A schematic diagram of an initial suspension point in an exemplary embodiment of this disclosure is shown; Figure 4 A flowchart illustrating a method for determining a first preset angle according to an exemplary embodiment of the present disclosure is shown. Figure 5 This diagram illustrates a flowchart of a method for updating a suspension point according to an exemplary embodiment of the present disclosure. Detailed Implementation

[0012] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided to make this disclosure more comprehensive and complete, and to fully convey the concept of the example embodiments to those skilled in the art. The described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a full understanding of embodiments of this disclosure. However, those skilled in the art will recognize that the technical solutions of this disclosure can be practiced with one or more of the specific details omitted, or other methods, components, apparatus, steps, etc., can be employed. In other instances, well-known technical solutions are not shown or described in detail to avoid obscuring various aspects of this disclosure.

[0013] The terms “a,” “an,” “the,” and “the” are used in this specification to indicate the presence of one or more elements / components / etc.; the terms “including” and “having” are used to indicate an open-ended inclusion and to mean that there may be other elements / components / etc. in addition to the listed elements / components / etc.; the terms “first” and “second” are used only as markings and are not a limitation on the number of objects.

[0014] Furthermore, the accompanying drawings are merely illustrative of this disclosure and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and therefore repeated descriptions of them will be omitted. Some block diagrams shown in the drawings are functional entities and do not necessarily correspond to physically or logically independent entities. These functional entities may be implemented in software, in one or more hardware modules or integrated circuits, or in different network and / or processor devices and / or microcontroller devices.

[0015] Figure 1 This diagram illustrates a flow chart of a method for hoisting a wind turbine drive train according to an exemplary embodiment of this disclosure. (See reference...) Figure 1 The method includes: Step S110: A first number of first double-ended studs are pre-embedded in the threaded holes of the main bearing mounting surface of the wind turbine front frame, wherein the first number is less than the second number of threaded holes on the main bearing mounting surface of the wind turbine, and the first double-ended studs are used to install and position the transmission chain. Step S120: Install the lifting device into the preset bolt holes on the main shaft flange of the transmission chain; Step S130: Using the preset bolt holes on the main shaft flange as lifting points, the transmission chain is lifted by the lifting device and the lifting adjustment is performed so that the lifting angle is a first preset angle, wherein the lifting angle is the angle between the transmission chain and the horizontal direction; Step S140: When the lifting angle is the first preset angle, the transmission chain is lifted to the top of the wind turbine nacelle by the lifting device, and the transmission chain is positioned so that the first double-headed stud embedded on the front frame passes through the main bearing seat of the transmission chain, and the torque arm of the gearbox of the transmission chain sits on the lower base of the elastic support assembly of the gearbox. Step S150: After the transmission chain is fully in place, other first double-ended studs are pre-embedded in the other threaded holes of the main bearing mounting surface of the wind turbine front frame.

[0016] exist Figure 1 In the technical solution provided by the embodiment shown, on the one hand, the present disclosure pre-embeds a small number of studs, and after the transmission chain is placed, other studs are pre-embedded. This facilitates rapid installation and alignment during the placement of the transmission chain and improves the placement efficiency of the transmission chain. On the other hand, the present disclosure adjusts the lifting angle during the lifting stage of the transmission chain to reduce repeated high-altitude posture adjustments after the transmission chain is lifted, thereby improving the safety of lifting.

[0017] The following is a detailed description of the specific implementation method of "step S110, pre-embedding a first number of first double-ended studs in the threaded holes of the main bearing mounting surface of the wind turbine front frame".

[0018] In one exemplary embodiment, the first number is less than the second number of threaded holes on the main bearing mounting surface of the wind turbine, and the first double-ended stud is used to install and position the drive chain.

[0019] For example, only a few (e.g., four) double-ended studs can be pre-embedded on the mounting surface of the front frame main bearing for initial positioning of the drive chain during placement. In this way, only a small number of studs are needed for alignment during the placement process, improving the placement efficiency of the drive chain.

[0020] The following is a detailed description of the specific implementation method of "step S120, installing the lifting device into the preset bolt holes on the main shaft flange of the transmission chain".

[0021] In one exemplary embodiment, before lifting the transmission chain, the following operations may be performed: cleaning the mounting surface of the elastic support assembly of the gearbox of the transmission chain and the mounting shaft of the torque arm of the gearbox; fitting the retaining rings inside the elastic support assembly of the gearbox onto the mounting shaft of the torque arm of the gearbox, with the chamfer facing outwards; and adding lubricating oil into the gearbox through the observation hole above the high-speed shaft of the gearbox of the transmission chain.

[0022] For example, the drive chain can be pre-installed before lifting it. Specifically, the mounting surfaces of the elastic support and the torque arm mounting shaft can be cleaned of oil and foreign matter using a cloth and cleaning agent. Then, the retaining rings inside the gearbox elastic support assembly are fitted onto the torque arm mounting shafts, with the chamfer facing outwards. Lubricating oil also needs to be added to the gearbox. For example, the inspection hole cover above the high-speed shaft of the gearbox can be opened to add lubricating oil. The amount of lubricating oil added should not be too much or too little; the amount of lubricating oil should be between the minimum and maximum oil level gauges.

[0023] In one exemplary embodiment, the preset bolt holes are a symmetrical group of bolt holes arranged symmetrically along the vertical center line of the main shaft flange. Based on this, exemplaryly, Figure 2 This diagram illustrates a flowchart of a method for determining a preset bolt hole according to an exemplary embodiment of this disclosure. (See reference...) Figure 2 The method may include steps S210 to S230. Wherein: In step S210, the center of gravity position, total weight, and radius of the distribution circle of bolt holes on the main shaft flange of the transmission chain are obtained.

[0024] In one exemplary embodiment, the top view of the spindle flange is as follows: Figure 3 As shown, for reference Figure 3 The transmission chain main shaft flange end face is equipped with multiple concentric rings of bolt holes centered on the main shaft rotation axis. In this disclosure, two symmetrical bolt holes on the left and right constitute a symmetrical bolt hole group, which serves as the lifting point of the transmission chain. All bolt holes in the same ring are located on the same distribution circle, the radius of which is the radius of the distribution circle. In the top view of the main shaft flange, there is a vertical symmetrical center line 31. Based on this center line, bolt holes are arranged in mirror pairs on the left and right sides. Each pair of mirror bolts constitutes a symmetrical bolt hole group. The horizontal distances from the two bolt holes in the same group to the vertical symmetrical center line are exactly equal. When lifting with this group of holes, the horizontal tension of the slings on both sides cancels each other out, and the transmission chain will not tilt to the left or right, only the pitch angle will change.

[0025] For example, based on the three-dimensional solid data model of the drivetrain, the corresponding real material densities can be assigned to all components such as the spindle, bearing housing, gearbox, and generator in 3D design software. Through the software's mass attribute analysis function, the total weight of the entire drivetrain and the axial distance from the center of gravity of the entire machine along the spindle axis to the spindle flange mounting face can be automatically extracted, thus obtaining the total weight and center of gravity position of the drivetrain. The total weight of the drivetrain can also be determined by actual weighing. For example, before assembling the drivetrain, the weight of each part of the drivetrain can be measured separately and then summed to obtain the total weight of the drivetrain.

[0026] Regarding the distribution circle radius of the bolt holes on the spindle flange, the distribution circle radius of the bolt rings on the spindle flange of the transmission chain can be read from the spindle flange machining drawings.

[0027] In step S220, with the first preset angle as the target balance posture, based on the center of gravity position, total weight and distribution circle radius, and based on the principle of static torque balance, the theoretical horizontal distance from the lifting point to the vertical symmetry center line of the main shaft flange required for the transmission chain to be in the target balance posture is calculated.

[0028] In one exemplary embodiment, the first preset angle is the final lifting angle that needs to be controlled and adjusted. When the lifting angle is the first preset angle, the transmission chain can be lifted and the transmission chain can be positioned and installed on the frame.

[0029] In one exemplary embodiment, the first preset angle is determined based on the adaptation relationship between the placement posture of the transmission chain and the first angle, wherein the first angle is the angle between the mounting surface of the main bearing housing on the front frame of the wind turbine and the horizontal plane.

[0030] For example, the first preset angle is the target static balance lifting angle of the transmission chain. When the transmission chain is hoisted to the top of the nacelle at this angle with a constant attitude, it can be directly positioned. At this time, the mounting through hole of the main bearing seat is coaxially aligned with the double-headed studs pre-embedded in the front frame and can be smoothly installed without scratches. At the same time, the lower support surface of the gearbox torque arm is parallel and aligned with the top surface of the elastic support base. After being positioned, it can be directly fitted into place without the need for secondary adjustment of the transmission chain attitude at high altitude.

[0031] For example, Figure 4 This diagram illustrates a flowchart of a method for determining a first preset angle according to an exemplary embodiment of this disclosure. (See reference...) Figure 4 The method may include steps S410 to S460.

[0032] In step S410, the range centered on the first angle is defined as the candidate angle range from the first angle minus the interval half-width threshold to the first angle plus the interval half-width threshold.

[0033] In one exemplary embodiment, the determination of the interval half-width threshold includes: obtaining the first critical deflection angle corresponding to the mechanical constraint of the lifting device, the second critical deflection angle corresponding to the interference constraint of the nacelle structure, and the third critical deflection angle corresponding to the fitting accuracy constraint of the torque arm; taking the minimum value among the first critical deflection angle, the second critical deflection angle, and the third critical deflection angle as the interval half-width threshold; wherein, the first critical deflection angle is the maximum single-sided tilt angle offset that does not exceed the limit of the spindle flange stress and the working load of the lifting device when lifting the transmission chain; the second critical deflection angle is the maximum single-sided tilt angle offset that does not collide with the nacelle structure during the placement process of the transmission chain; and the third critical deflection angle is the maximum single-sided tilt angle offset that allows the lower support surface of the torque arm to remain parallel to the top surface of the elastic support base.

[0034] For example, the mechanical constraints of the lifting equipment are safety constraints that limit the stress on the core load-bearing components during lifting to prevent it from exceeding the limit. The corresponding indicators are the local stress at the lifting point of the main shaft flange and the actual working load of the lifting equipment. These two stress indicators can be monitored in real time by gradually increasing the unilateral tilt angle offset starting from a reference angle through digital twin simulation or finite element simulation experiments. When the stress on the main shaft flange reaches the maximum allowable value of the material, or the working load of the lifting equipment reaches the rated maximum value—that is, as long as either indicator reaches its upper limit—the corresponding unilateral tilt angle offset is the first critical deflection angle. Exceeding this deflection angle poses a safety risk of flange cracking under stress and lifting equipment overload failure.

[0035] Cabin structural interference constraints are safety constraints that limit spatial interference of equipment during placement. The core principle is to ensure that the drivetrain does not collide with fixed structures within the cabin, such as maintenance platforms, electrical cabinets, piping, and the housing, throughout its descent to the installation position. This can be simulated through experiments, gradually increasing the unilateral tilt angle to mimic the complete placement trajectory. When the minimum distance between any part of the drivetrain and the cabin's internal structure drops to zero, indicating an impending collision, the maximum unilateral tilt angle at this point is the second critical tilt angle. If the tilt angle exceeds this critical value, the drivetrain will inevitably collide with the cabin's internal structure during placement, causing damage to equipment components.

[0036] The torque arm fitting accuracy constraint is a constraint that limits the final assembly quality. Its core is to ensure that after the transmission chain is in place, the lower support surfaces of the torque arms on both sides of the gearbox can maintain parallel and uniform contact with the top surface of the lower elastic support base. This can be achieved through simulation of the final positioning posture, gradually increasing the single-sided tilt angle offset to detect the parallelism deviation of the two mating surfaces. When the parallelism deviation just exceeds the acceptable range allowed by the assembly process, the corresponding single-sided tilt angle offset is the third critical offset angle. If the tilt angle offset is greater than this critical value, the lower support surface of the torque arm and the elastic support base will have an skewed fit, leading to uneven stress on the elastic support, abnormal noise during operation, or premature wear, failing to meet the assembly accuracy requirements.

[0037] For example, as mentioned earlier, the first angle is the angle between the mounting surface of the main bearing housing on the front frame of the wind turbine and the horizontal plane. Throughout the determination of the first preset angle, the half-width threshold of the interval is calculated based on this first angle. Because after the drive train is positioned and secured, the bottom surface of the main bearing housing must be completely flush with and fixed to the mounting surface of the front frame. At this point, the theoretical pitch angle of the entire drive train is equal to the tilt angle of the mounting surface of the front frame. This angle is a fixed value determined by the machining and installation accuracy of the front frame and is the core of the entire hoisting process. All adjustments to the hoisting posture are ultimately aimed at approaching this installation posture.

[0038] It should be noted that the tilt angle of the front frame mounting surface is an objective parameter that can be directly measured on-site, without relying on the hoisting experience of the workers. The half-width of the interval and the candidate angle calibrated based on this can be directly adapted to the actual working conditions of different models and different installation sites, avoiding the problem of poor adaptability caused by using experience-based angles as a benchmark.

[0039] For example, the minimum value among the first critical deflection angle, the second critical deflection angle, and the third critical deflection angle can be used as the half-width threshold of the interval. This ensures that the placement process of the transmission chain will not cause any hoisting safety risks or collision damage to the internal structure of the engine room. It also ensures that after the transmission chain is placed, the lower support surfaces of the torque arms on both sides of the gearbox can maintain parallel and uniform contact with the top surface of the elastic support base below, thus avoiding abnormal noises during operation.

[0040] In step S420, the first angle is used as the first candidate angle traversal object, and the candidate angles in the candidate angle interval are traversed alternately to both sides of the candidate angle interval with a preset step size.

[0041] For example, angles within a candidate angle interval are symmetrical about a first angle. The closer an angle is to the first angle, the smaller its deviation from the first angle, and the more likely it is to meet the final requirement. Therefore, using the first angle as the first candidate angle traversal object, the candidate angles within the candidate angle interval are traversed alternately to both sides of the candidate angle interval with a preset step size. The current traversed object is checked to see if it meets the verification conditions, thus obtaining the final first preset angle. This improves the efficiency of determining the first preset angle.

[0042] The preset step size can be customized based on experience or needs, and this exemplary embodiment does not impose any special limitations on it.

[0043] Taking a preset step size of 0.2 degrees, a half-width threshold of 2 degrees, and a first angle of 5 degrees as an example, if the candidate angle range is 3 to 7 degrees, first determine if 5 degrees meets the verification condition. If not, determine if 4.8 degrees meets the verification condition. If not, determine if 5.2 degrees meets the verification condition. If not, determine if 4.6 degrees meets the verification condition. If not, continue iterating through 5.4 degrees to determine if it meets the verification condition, and so on, until the first preset angle is determined. If no solution meets the verification condition after iterating through all candidate angles within the candidate angle range, the half-width threshold can be expanded, the candidate angle range can be redefined, and the iteration can be performed again.

[0044] In step S430, for the currently traversed candidate angle, the lifting angle is used to simulate the process of the transmission chain being lowered from the top of the nacelle to the front frame.

[0045] For example, for the candidate angle currently being traversed, such as 5 degrees, the lifting posture of the transmission chain can be set to a pitch angle of 5 degrees in the digital twin model to simulate the complete placement process of the transmission chain falling at a constant speed from directly above the installation position in the engine room.

[0046] In step S440, it is determined whether the simulation results meet the verification conditions. If they do, proceed to step S450; otherwise, proceed to step S460.

[0047] In one exemplary implementation paradigm, the verification conditions include: when the mounting through hole of the main bearing housing falls through the pre-embedded first double-ended stud, the minimum clearance between the outer wall of the first double-ended stud and the hole wall of the main bearing housing is greater than or equal to a preset safety threshold; the transmission chain does not collide with the nacelle structure during the placement process; after the transmission chain is placed, the lower support surface of the torque arm of the transmission chain gearbox is parallel to the top surface of the elastic support base; the working load of the lifting device is less than or equal to the rated load; and the additional bending moment and stress at the lifting point of the main shaft flange are within any of the following safe ranges.

[0048] For example, the minimum radial clearance between the outer wall of the pre-embedded first double-ended stud and the wall of the main bearing housing mounting hole can be measured during the simulation process. When the minimum radial clearance is greater than or equal to a preset safety threshold, the sub-verification condition is considered successfully verified. Then, the next sub-verification condition is verified, such as detecting the minimum distance between the transmission chain body, the lifting device and the inner wall of the engine room, the maintenance platform, and other fixed structures. If the minimum distance is greater than the preset safety threshold, it is determined that there is no collision risk, and the sub-verification condition is also successfully verified. Then, the next sub-verification condition is verified, such as determining the lower support surface of the gearbox torque arm under the final positioning state. If the angle between the sub-verification condition and the top surface of the base under the elastic support is less than a preset angle threshold, then the sub-verification condition is considered successfully verified. Next, the next sub-verification condition is verified, such as whether the working load of the lifting device during the simulation is less than or equal to the rated load. If so, the sub-verification condition is also considered successfully verified. Then, the next sub-verification condition is verified, such as whether the additional bending moment and stress at the main shaft flange lifting point are within the safe range. If both are within the safe range, the sub-verification condition is considered successfully verified; if either is outside the safe range, the sub-verification condition is considered to have failed. If all sub-verification conditions are successfully verified, the simulation result is considered to meet the verification conditions; otherwise, the simulation result is considered to not meet the verification conditions.

[0049] In one exemplary implementation, the verification condition is composed of multiple sub-verification conditions, each of which has a corresponding preset priority. The preset priority of the sub-verification condition can be customized based on engineering experience and on-site installation requirements. For example, the preset priority can be determined based on the importance of the verification indicators corresponding to each sub-verification condition to the wind turbine hoisting and installation process. For instance, the higher the importance and risk level of the verification item, the higher its corresponding preset priority.

[0050] Based on this, sub-verification conditions can be traversed according to a preset priority. If the simulation result indicates that the currently traversed candidate angle meets the currently traversed sub-verification condition, the next sub-verification condition can be traversed until all sub-verification conditions have been traversed and the currently traversed candidate angle meets the last sub-verification condition. In this case, it is determined that the simulation result indicates that the currently traversed candidate angle meets the verification condition. If the simulation result indicates that the currently traversed candidate angle does not meet the currently traversed sub-verification condition, it is determined that the simulation result indicates that the currently traversed candidate angle does not meet the verification condition, and the next candidate angle can be traversed.

[0051] In step S450, the traversal is stopped, and the candidate angle currently traversed is determined as the first preset angle.

[0052] For example, when the simulation results meet the verification conditions, the candidate angle currently being traversed can be directly determined as the first preset angle.

[0053] In step S460, the next candidate angle is traversed, and the process proceeds to step S430.

[0054] For example, if the simulation results indicate that the currently traversed candidate angle does not meet the verification conditions, then the next candidate angle is traversed, and the simulation is performed again based on the next traversed candidate angle. The verification conditions are then checked again on the simulation results until the first preset angle is determined or all candidate angles have been traversed.

[0055] Through steps S410 to S460, the minimum value of the multi-constraint critical deflection angle is used to define the symmetrical candidate interval, pre-excluding all angles that are bound to exceed the limit. This narrows the traversal range from the root, improving the efficiency of determining the first preset angle. Furthermore, based on the priority of the sub-verification conditions, if a high-priority verification condition is not met, the verification of the current candidate angle can be terminated directly, without needing to complete the simulation calculation of all sub-items. While ensuring the requirements are met, the efficiency of determining the first preset angle is further improved.

[0056] After determining the first preset angle through steps S410 to S460, the preset bolt holes can be determined based on the first preset angle. The preset bolt holes can be understood as the initial lifting point positions during the lifting of the transmission chain. They are obtained through theoretical calculations, but in reality, deviations may occur due to the lifting environment, such as wind speed, and adjustments may be necessary during the actual lifting process. However, through the preliminary theoretical calculations, the probability of adjustments during the actual lifting process and the duration of each adjustment can be reduced, thereby improving the overall lifting efficiency of the transmission chain.

[0057] For example, the theoretical horizontal distance from the suspension point to the vertical center line of symmetry can be obtained by the following formula (1): (1) In formula (1), L is the axial distance of the center of gravity of the transmission chain along the rotation axis of the main shaft, relative to the mounting end face of the main shaft flange, determined according to the position of the center of gravity. R The radius of the distribution circle, This is the theoretical horizontal distance from the lifting point to the vertical center line of symmetry. This is the first preset angle. It should be noted that the total weight of the transmission chain appears on both sides of the above formula (1), and they directly cancel each other out during calculation, without affecting the overall result. The final calculation result.

[0058] In step S230, the actual horizontal distance from each symmetrical bolt hole group on the spindle flange to the vertical symmetrical center line of the spindle flange is obtained, and the symmetrical bolt hole group with the smallest absolute value of the difference between the actual horizontal distance and the theoretical horizontal distance is determined as the preset bolt hole.

[0059] For example, similarly, the total lateral spacing between all symmetrical bolt hole groups in each circle can be obtained from the flange construction drawings. Dividing this total spacing by two determines the actual horizontal distance from a single hole in that symmetrical bolt hole group to the vertical symmetrical center line of the main shaft flange. The absolute value of the difference between each actual horizontal distance and the theoretical horizontal distance is calculated, and then the symmetrical bolt hole group with the smallest absolute value of the difference is determined as the preset bolt hole.

[0060] It should be noted that the spindle flange may have multiple rings of bolt holes, such as... Figure 3 As shown, there are two rings of bolt holes. For the two rings of bolt holes, first substitute the radius of the distribution circle corresponding to each ring, calculate the theoretical horizontal distance corresponding to each ring separately, and select the symmetrical bolt hole group with the smallest absolute value of the difference within each ring to obtain the candidate preset bolt holes for each ring. Then compare the matching deviations corresponding to all candidate hole groups and select the group with the smallest deviation as the final preset bolt holes. For example, the preset bolt holes of the inner ring are determined when the absolute value of the difference is 0.2, and the preset bolt holes of the outer ring are determined when the absolute value of the difference is 0.1. Then the preset bolt holes of the outer ring are the final preset bolt holes. There may also be a case where the inner ring has no solution because the square root in formula (1) is negative. In this case, the preset bolt holes of the outer ring are directly determined as the final preset bolt holes. Alternatively, based on experience, only the preset bolt holes corresponding to the outermost ring, i.e. the bolt ring with the largest radius, can be calculated directly.

[0061] The following is a detailed description of the specific implementation of "step S130, using the preset bolt holes on the main shaft flange as lifting points, lifting the transmission chain with the lifting device, and adjusting the lifting angle to make the lifting angle the first preset angle".

[0062] In one exemplary embodiment, the lifting angle is the angle between the transmission chain and the horizontal direction. Specifically, the transmission chain is a complex assembly composed of multiple components such as the main shaft, main shaft bearing, main bearing housing, and gearbox. The tilt angles of different components vary. The lifting angle can be understood as the angle between the rotation axis of the main shaft and the horizontal plane when the transmission chain is in a stable static balance lifting state.

[0063] For example, one implementation of step S130 may include: using a preset bolt hole on the main spindle flange as a lifting point, lifting the transmission chain with the lifting device; if the lifting angle does not meet the first preset angle, updating the lifting point based on other bolt holes on the main spindle flange, so as to re-lift the transmission chain according to the updated lifting point, repeating the process until the lifting angle is the first preset angle.

[0064] For example, a preset bolt hole can be used as the initial lifting point. The lifting tool can be used to lift the transmission chain through the initial lifting point. It is then determined whether the lifting angle is the first preset angle. If it is, the transmission chain can be lifted smoothly based on the lifting angle. If not, the lifting needs to be adjusted so that the lifting angle is the first preset angle.

[0065] For example, when the lifting angle does not meet the first preset angle, updating the lifting point based on other bolt holes on the spindle flange includes: when the lifting angle is greater than the first preset angle, updating the lifting point according to a symmetrical bolt hole group that is closer to the vertical symmetry center line of the spindle relative to the bolt hole corresponding to the current lifting point; when the lifting angle is less than the first preset angle, updating the lifting point according to a symmetrical bolt hole group that is farther away from the vertical symmetry center line of the spindle relative to the bolt hole corresponding to the current lifting point.

[0066] For example, Figure 5 This diagram illustrates a flowchart of a method for updating a suspension point according to an exemplary embodiment of this disclosure. (See reference...) Figure 5 The method may include steps S510 to S530. Wherein: In step S510, a digital twin model of the transmission chain hoisting is built, and each symmetrical bolt hole group on the main shaft flange is used as a hoisting point to simulate the static balance posture of the transmission chain after hoisting, so as to obtain the theoretical hoisting angle corresponding to each symmetrical bolt hole group.

[0067] For example, a digital twin simulation model of the transmission chain hoisting can be built. This model contains a complete three-dimensional geometric entity of the transmission chain, the mass attributes of each component (total mass, center of gravity coordinates, moment of inertia), the precise position coordinates of all bolt holes on the main shaft flange, and the mechanical constraint elements of the flexible slings. The initial attitude of the transmission chain in the model is set to horizontal (i.e., the lifting angle is 0). Each group of symmetrical bolt holes is selected as a hoisting point, and sling connection constraints are applied to the two bolt hole positions in that group. The static equilibrium solver is then activated to simulate the entire process of the transmission chain swinging freely under gravity until it reaches a stable static equilibrium attitude. After the attitude converges and stabilizes, the pitch angle of the transmission chain's main shaft axis relative to the horizontal plane is extracted; this is the theoretical lifting angle corresponding to that symmetrical bolt hole group.

[0068] In step S520, the lifting angle adjustment step of radially adjacent symmetrical bolt hole groups is determined according to the theoretical lifting angle corresponding to each symmetrical bolt hole group.

[0069] For example, all symmetrical bolt hole groups can be sorted in ascending order of their horizontal radial distance to the vertical center line of symmetry. The theoretical lifting angle difference between any two radially adjacent symmetrical bolt hole groups can then be calculated. This difference represents the lifting angle adjustment step for each radially adjacent symmetrical bolt hole group. In other words, radially adjacent can be understood as symmetrical bolt hole groups that are adjacent in position after being sorted by the horizontal radial distance from the lifting point to the vertical center line of symmetry, corresponding to adjacent bolt hole groups arranged circumferentially on the flange end face.

[0070] Since the bolt holes in the same circle are evenly arranged circumferentially, the horizontal distance increment of adjacent hole groups is basically the same. Therefore, the adjustment step length of each group is roughly equal. In practical applications, precise hole selection can be achieved by using the precise step length of each segment, or the average step length can be used for rapid on-site estimation. This exemplary embodiment does not impose any special limitations on this.

[0071] In step S530, the first difference between the current lifting angle and the first preset angle is obtained, the step size is adjusted according to the lifting angle, the target symmetrical bolt hole group with the smallest second difference between the angle change and the first difference is determined, and the target symmetrical bolt hole group is used as the updated lifting point.

[0072] For example, the current lifting angle corresponding to the symmetrical bolt hole group actually used in the current lifting operation can be obtained, and the difference between it and the first preset angle can be calculated to obtain the first difference value between the current angle and the first preset angle. The direction of deviation (i.e., whether it is too large or too small) can be determined. Then, according to the adjustment step size mentioned above, the angular change between the lifting angle of other symmetrical bolt hole groups indicated by the deviation direction and the current lifting angle can be determined. The symmetrical bolt hole group whose angular change value is closest to the first difference value can be selected as the target symmetrical bolt hole group, and thus it can be used as the new lifting point.

[0073] For example, the first preset angle for this hoisting is 8 degrees. During the initial trial hoisting, the two front hoisting points are distributed at the 10th outer ring hole on the left and right of the center line of the main shaft flange. The corresponding current hoisting angle is 7.2 degrees. The first difference is calculated to be 8-7.2=0.8 degrees, which means that the hoisting angle needs to be increased by 0.8 degrees. The theoretical lifting angle change between the 11th outer ring hole on the left and right of the spindle flange centerline and the current lifting point (i.e., the 10th outer ring hole on the left and right of the spindle flange centerline) is 0.41 degrees, which is less than 0.8 degrees. Therefore, we need to determine the theoretical lifting angle change between the 12th outer ring hole on the left and right of the spindle flange centerline and the current lifting point. It is known that the theoretical lifting angle change between the 11th and 12th outer ring holes on the left and right of the spindle flange centerline is 0.38 degrees. Therefore, the theoretical lifting angle change between the 12th outer ring hole on the left and right of the spindle flange centerline and the current lifting point is 0.41 + 0.38 = 0.79 degrees, which is closest to 0.8 degrees. At this point, the 12th outer ring hole can be updated as the new lifting point. After changing the lifting point, lift again and check the deviation between the actual lifting angle and the first preset angle. If the deviation is within the allowable accuracy range of the lifting, stop adjusting. If it still does not meet the requirements, continue to adjust to the adjacent hole group according to the same logic until the deviation between the lifting angle and the first preset angle is within the allowable accuracy range of the lifting.

[0074] The following is a detailed description of the specific implementation of "step S140, in the case that the lifting angle is the first preset angle, the transmission chain is lifted to the top of the wind turbine nacelle by the lifting device, and the transmission chain is positioned so that the first double-headed stud pre-embedded on the front frame passes through the main bearing seat of the transmission chain, and the torque arm of the gearbox of the transmission chain sits on the lower base of the elastic support assembly of the gearbox".

[0075] For example, after the aforementioned steps, the drive chain has been adjusted to the first preset angle through the selected symmetrical bolt hole group lifting points. The lifting posture is stable, and the working load of the lifting equipment and the stress at the main shaft flange lifting points are all within the safety threshold. At this point, the drive chain lifting and positioning operation can be performed. The entire drive chain can be smoothly lifted and transported to the front frame installation position of the wind turbine nacelle. The horizontal position of the drive chain is adjusted so that the main bearing housing installation area is roughly aligned with the installation reference of the front frame, and the gearbox torque arm is basically corresponding to the projected position of the lower elastic support assembly. After being lifted into place, the drive chain is suspended at a preset height from the front frame installation surface. After the overall posture is stable and there is no obvious shaking, the subsequent alignment operation is then performed.

[0076] Since the lifting angle has been pre-adjusted to the first preset angle that matches the tilt angle of the front frame mounting surface, the overall pitch attitude of the transmission chain is consistent with the final installation reference attitude. No additional high-altitude pitch angle adjustment is required in the hovering state, which greatly reduces the difficulty and risk of high-altitude alignment.

[0077] In the high-position hovering state, by finely adjusting the lateral and circumferential positions of the transmission chain, the first double-ended stud pre-embedded on the front frame is made approximately coaxial with the mounting through hole of the main bearing seat. The top of all studs falls within the projection range of the corresponding through hole, and the gaps around the holes and studs are basically uniform. Furthermore, the lower support surfaces of the torque arms on both sides of the gearbox are aligned vertically with the top surface of the lower base of the lower elastic support assembly. The projection of the torque arms falls completely within the bearing range of the lower base without any obvious offset.

[0078] Then, the lifting equipment is controlled to lower the transmission chain at a low and uniform speed. Throughout the descent, on-site personnel simultaneously monitor the coordination status of two key components. If any abnormality occurs, the descent is stopped immediately. For example, the gap between the first double-ended stud and the wall of the main bearing housing mounting hole is observed in real time to ensure that the stud is inserted vertically along the center of the hole without scraping or jamming. When the transmission chain falls to a preset distance from the mounting surface, the descent is paused, and the horizontal position and circumferential posture of the transmission chain are finely adjusted again to complete the final precision alignment, ensuring that the coaxiality of the stud and the through hole, and the alignment accuracy of the torque arm and the lower base meet the assembly requirements. After precise alignment, continue lowering the transmission chain at a lower and uniform speed until all the first double-ended studs pre-embedded on the front frame are successfully inserted into the corresponding mounting holes of the main bearing housing, the top of the stud protrudes normally from the end face of the hole, the bottom surface of the main bearing housing is stably attached to the mounting surface of the front frame, and the lower support surfaces of the torque arms on both sides of the gearbox are synchronously and stably placed on the top surface of the lower base of the elastic support assembly. The support surfaces are in uniform contact, with no one side suspended or skewed contact. Then the positioning is considered complete.

[0079] The following is a detailed description of the specific implementation of "step S150, after the transmission chain is fully in place, pre-embed other first double-ended studs in other threaded holes in the main bearing mounting surface of the wind turbine front frame".

[0080] For example, before placement, only a few first double-ended studs are pre-embedded in the positioning threaded holes on the mounting surface of the front frame main bearing as guide alignment references when the drive chain falls. After the drive chain is fully in place, the remaining first double-ended studs are pre-embedded in the remaining threaded holes. This method can significantly reduce the alignment difficulty of simultaneously installing multiple studs during placement, while avoiding damage to the stud threads during placement.

[0081] For example, after the transmission chain is fully in place, the mating gap of the main bearing housing, the parallelism of the torque arm, and the protrusion length of the pre-embedded guide studs can be checked first. After all the indicators are qualified, the remaining first double-ended studs corresponding to the remaining pre-embedded threaded holes can be installed.

[0082] After all the first double-ended studs are pre-embedded, the exposed length, perpendicularity, and thread integrity of all studs (including a small number of pre-embedded guide studs) are fully checked. After confirming that all are qualified, flat washers and elastic washers are installed in sequence, the main bearing housing fastening nuts are tightened, and the final locking is completed by using a diagonal step-by-step tightening method according to the specified torque value, so as to realize the fixed connection between the transmission chain main bearing housing and the front frame.

[0083] Select the spindle flange bolt holes based on the initial lifting points. The two lifting points are located on the left and right of the 10th outer ring hole on the centerline of the spindle flange (e.g., Figure 3 Taking bolt holes 32 and 33 as shown, and the first preset angle as 8 degrees, a few (e.g., 4) double-ended studs for initial positioning can be pre-embedded on the main bearing mounting surface of the front frame. Then, the transmission chain can be pre-installed. This involves cleaning the oil and foreign matter from the mounting surface of the elastic support and the torque arm mounting shaft with a cloth and cleaning agent. The four retaining rings in the gearbox elastic support assembly are then fitted onto the torque arm mounting shaft, with the chamfer facing outwards. Before hoisting, lubricating oil needs to be added to the gearbox. The observation hole cover above the high-speed shaft of the gearbox is opened to add lubricating oil from this point.

[0084] Then, hoist the lifting device at the initial lifting point, using specific bolt holes on the main shaft flange (such as the 10th hole to the left or right of the center line) as the lifting point. Slowly lift the drive chain, measuring the angle between the drive chain and the horizontal plane to approximately 8 degrees. If it does not meet the 8-degree requirement, lower the drive chain onto the tooling and readjust the front lifting point to ensure the lifting angle meets the 8-degree requirement. For example, it is suggested that the front lifting point of the drive chain be installed at the 10th hole to the left or right of the center line, but this is only a theoretical value. On-site testing is required to confirm that the lifting angle of the drive chain is 8 degrees. If it does not meet the 8-degree requirement, the position of the front lifting point hole needs to be adjusted. The closer the hole is to the center line, the smaller the lifting angle of the drive chain; the farther the hole is from the center line, the larger the lifting angle of the drive chain. Then, lift the drive chain to the top of the lower nacelle. The crane slowly lowers the hook, and the pre-embedded bolts on the front frame pass through the drive chain main bearing housing. The gearbox torque arm is positioned on the base of the four elastic supports on the left and right sides, finally positioning the drive chain on the frame. After it is fully positioned, pre-embed the mounting bolts of the uninstalled bearing housings.

[0085] This disclosure pre-matches lifting points and calibrates angles using digital twin simulation, allowing for the direct determination of optimal lifting points and target postures before hoisting. This eliminates the need for repeated on-site trial lifts and adjustments to sling lengths, significantly reducing on-site commissioning time and improving hoisting efficiency. Furthermore, this disclosure simplifies the synchronous alignment of multiple studs to the alignment of a small number of guide studs, significantly reducing the difficulty of high-altitude alignment and minimizing the time spent on repeated fine-tuning during the placement process, further improving construction efficiency and safety.

[0086] Furthermore, the lifting target angle, lifting point, etc. in this disclosure are determined through simulation, which does not rely on the personal experience and operation level of on-site construction personnel, thus improving the universality and standardization of the transmission chain lifting method.

[0087] Furthermore, it should be noted that the above figures are merely illustrative representations of the processes included in the method according to exemplary embodiments of the present invention, and are not intended to be limiting. It is readily understood that the processes shown in the above figures do not indicate or limit the temporal order of these processes. Additionally, it is readily understood that these processes may be executed synchronously or asynchronously, for example, in multiple modules.

[0088] Although the steps of the method in this disclosure are described in a specific order in the accompanying drawings, this does not require or imply that the steps must be performed in that specific order, or that all the steps shown must be performed to achieve the desired result. Additional or alternative steps may be omitted, multiple steps may be combined into one step, and / or a step may be broken down into multiple steps.

[0089] It should be understood that this disclosure is not limited to the specific methods, steps, or structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. Those skilled in the art will readily conceive of other embodiments based on the specific implementations provided in this disclosure. Therefore, the specific implementations provided in this disclosure are merely exemplary, and the scope and spirit of this disclosure are indicated by the claims, and should cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary technical means in the art not disclosed in this disclosure.

Claims

1. A method for hoisting a wind turbine drive chain, characterized in that, include: A first number of first double-ended studs are pre-embedded in the threaded holes of the main bearing mounting surface of the wind turbine front frame, wherein the first number is less than the second number of threaded holes on the main bearing mounting surface of the wind turbine, and the first double-ended studs are used to install and position the transmission chain. Install the lifting device into the pre-set bolt holes on the main shaft flange of the drive chain; Using the preset bolt holes on the main shaft flange as lifting points, the transmission chain is lifted by the lifting device and the lifting is adjusted so that the lifting angle is a first preset angle, wherein the lifting angle is the angle between the transmission chain and the horizontal direction; When the lifting angle is the first preset angle, the transmission chain is lifted to the top of the wind turbine nacelle by the lifting device, and the transmission chain is positioned so that the first double-headed stud pre-embedded on the front frame passes through the main bearing seat of the transmission chain, and the torque arm of the gearbox of the transmission chain sits on the lower base of the elastic support assembly of the gearbox. After the transmission chain is fully in place, other first double-ended studs are pre-embedded in the other threaded holes of the main bearing mounting surface of the wind turbine front frame.

2. The method according to claim 1, characterized in that, The first preset angle is determined based on the adaptation relationship between the placement posture of the transmission chain and the first angle, where the first angle is the angle between the mounting surface of the main bearing housing on the front frame of the wind turbine and the horizontal plane.

3. The method according to claim 2, characterized in that, The method for determining the first preset angle includes: The range centered on the first angle is defined as the candidate angle range from the first angle minus the interval half-width threshold to the first angle plus the interval half-width threshold. Using the first angle as the first candidate angle traversal object, the candidate angles in the candidate angle interval are traversed alternately to both sides of the candidate angle interval with a preset step size; For the candidate angle currently being traversed, the process of the transmission chain being lowered from the top of the nacelle to the front frame is simulated using the current candidate angle as the lifting angle. If the simulation result indicates that the current candidate angle meets the verification conditions, the traversal is stopped and the current candidate angle is determined as the first preset angle. If the simulation result indicates that the current candidate angle does not meet the verification conditions, the traversal of the next candidate angle continues. The verification conditions include: when the mounting hole of the main bearing housing falls through the pre-embedded first double-ended stud, the minimum gap between the outer wall of the first double-ended stud and the hole wall of the main bearing housing is greater than or equal to a preset safety threshold; the transmission chain does not collide with the nacelle structure during the placement process; after the transmission chain is placed, the lower support surface of the torque arm of the transmission chain gearbox is parallel to the top surface of the elastic support base; the working load of the lifting device is less than or equal to the rated load; and the additional bending moment and stress at the lifting point of the main shaft flange are within any of the following safe ranges.

4. The method according to claim 3, characterized in that, The verification conditions include multiple sub-verification conditions, each sub-verification condition having a preset priority; the method further includes: According to the preset priority, the sub-verification conditions are traversed. If the simulation result indicates that the candidate angle currently traversed meets the current sub-verification condition, the next sub-verification condition is traversed until all the sub-verification conditions are traversed and the candidate angle currently traversed meets the last sub-verification condition. Then, it is determined that the simulation result indicates that the candidate angle currently traversed meets the verification condition. If the simulation results indicate that the currently traversed candidate angle does not meet the current sub-verification condition, then determine that the simulation results indicate that the currently traversed candidate angle does not meet the verification condition, and traverse the next candidate angle.

5. The method according to claim 3, characterized in that, The determination method for the interval half-width threshold includes: The first critical deflection angle corresponding to the mechanical constraints of the spreader, the second critical deflection angle corresponding to the interference constraints of the engine room structure, and the third critical deflection angle corresponding to the fitting accuracy constraints of the torque arm are obtained respectively. The minimum value among the first critical deflection angle, the second critical deflection angle, and the third critical deflection angle is used as the interval half-width threshold. Wherein, the first critical deflection angle is the maximum single-sided tilt angle offset that does not exceed the limits of the main shaft flange stress and the working load of the lifting equipment when the lifting equipment is hoisting the transmission chain; the second critical deflection angle is the maximum single-sided tilt angle offset that does not collide with the nacelle structure during the placement process of the transmission chain; and the third critical deflection angle is the maximum single-sided tilt angle offset that allows the lower support surface of the gearbox torque arm to remain parallel to the top surface of the elastic support base.

6. The method according to claim 1, characterized in that, Before lifting the drive chain, the method further includes: Clean the mounting surface of the elastic support assembly of the gearbox of the transmission chain and the mounting shaft of the torque arm of the gearbox; Fit the retaining rings inside the gearbox elastic support assembly onto the mounting shaft of the gearbox torque arm, with the chamfer facing outwards; Lubricating oil is added to the gearbox through the observation hole above the high-speed shaft of the gearbox in the transmission chain.

7. The method according to claim 1, characterized in that, The step of using the preset bolt holes on the main shaft flange as lifting points, lifting the transmission chain with the lifting device, and adjusting the lifting angle to a first preset angle includes: Using the preset bolt holes on the main spindle flange as lifting points, the transmission chain is lifted by the lifting device. If the lifting angle does not meet the first preset angle, the lifting points are updated based on other bolt holes on the main spindle flange, so that the transmission chain can be lifted again according to the updated lifting points. This process is repeated until the lifting angle is the first preset angle.

8. The method according to claim 7, characterized in that, The preset bolt holes are a symmetrical group of bolt holes symmetrically arranged along the vertical center line of the main shaft flange. The step of updating the lifting point based on other bolt holes on the main shaft flange when the lifting angle does not meet the first preset angle includes: If the lifting angle is greater than the first preset angle, the lifting point is updated according to the symmetrical bolt hole group that is closer to the vertical symmetrical center line of the main shaft relative to the bolt hole corresponding to the current lifting point. If the lifting angle is less than the first preset angle, the lifting point is updated according to the symmetrical bolt hole group that is further away from the vertical symmetrical center line of the main shaft relative to the bolt hole corresponding to the current lifting point.

9. The method according to claim 7, characterized in that, The preset bolt holes are a symmetrical group of bolt holes symmetrically arranged along the vertical center line of the main shaft flange. The step of updating the lifting point based on other bolt holes on the main shaft flange when the lifting angle does not meet the first preset angle includes: A digital twin model of the transmission chain hoisting was built, and each symmetrical bolt hole group on the main shaft flange was used as a hoisting point to simulate the static balance posture of the transmission chain after hoisting, so as to obtain the theoretical hoisting angle corresponding to each symmetrical bolt hole group. Based on the theoretical lifting angle corresponding to each symmetrical bolt hole group, determine the lifting angle adjustment step of radially adjacent symmetrical bolt hole groups; Obtain the first difference between the current lifting angle and the first preset angle, adjust the step size according to the lifting angle, determine the target symmetrical bolt hole group with the smallest second difference between the angle change and the first difference, and use the target symmetrical bolt hole group as the updated lifting point.

10. The method according to claim 1, characterized in that, The preset bolt holes are a symmetrical group of bolt holes arranged symmetrically along the vertical center line of the main shaft flange. The method for determining the preset bolt holes includes: Obtain the center of gravity position, total weight, and radius of the distribution circle of bolt holes on the main shaft flange of the transmission chain; With the first preset angle as the target balance posture, based on the center of gravity position, total weight and distribution circle radius, and based on the static torque balance principle, the theoretical horizontal distance from the lifting point to the vertical symmetry center line of the main shaft flange required for the transmission chain to be in the target balance posture is calculated. Obtain the actual horizontal distance from each symmetrical bolt hole group on the spindle flange to the vertical symmetrical center line of the spindle flange, and determine the symmetrical bolt hole group with the smallest absolute value of the difference between the actual horizontal distance and the theoretical horizontal distance as the preset bolt hole.

Images