Vibration noise optimization method for planet row coaxial speed reducer

Abstract

The invention relates to the technical field of reducer vibration noise optimization, and discloses a planet row coaxial reducer vibration noise optimization method, which comprises the steps of obtaining initial assembly parameters of a reducer, collecting load measurement signals of planet wheels of the reducer under an order frequency sweeping working condition, converting the load measurement signals into equivalent meshing loads based on a calibration curve, and calculating the equivalent meshing loads according to the equivalent meshing loads. Calculating a load imbalance coefficient according to the equivalent meshing load, and taking a peak value of the load imbalance coefficient as a first evaluation index; shell radial acceleration and sound pressure signals are synchronously collected under the order frequency sweeping working condition, the side-band ratio is calculated, and the peak value of the side-band ratio is taken as a second evaluation index; and performing diagnosis shunting based on the first evaluation index and the second evaluation index, determining an assembly parameter which is adjusted preferentially, executing iterative adjustment, and outputting a final assembly parameter after iteration is completed. According to the method, uniform load unbalance caused by assembly errors and side band amplification caused by geometric eccentricity can be effectively separated and solved, and vibration and noise of the speed reducer are reduced fundamentally.

Description

Technical Field

[0001] This invention relates to the field of vibration and noise optimization technology for speed reducers, specifically a method for optimizing the vibration and noise of a planetary gearbox coaxial speed reducer. Background Technology

[0002] Planetary gearbox coaxial reducers are widely used in new energy vehicles, construction machinery, and industrial transmissions due to their advantages such as large transmission ratio, compact structure, and high transmission efficiency. However, in practical applications, planetary gearbox reducers commonly suffer from vibration and noise problems, especially under medium- and high-speed operating conditions. The periodic modulation of meshing stiffness significantly amplifies the meshing frequency and its side-band energy, manifesting as gear squealing and housing resonance. Vibration and noise not only affect the overall comfort and reliability of the machine but also lead to accelerated tooth surface fatigue and shortened bearing life.

[0003] In existing technologies, the industry commonly employs methods such as tooth surface modification, structural floating design, or NVH testing and screening at the final stage to reduce noise. While these methods have some effect at the design or quality control levels, they have significant limitations: tooth surface modification requires pre-determined parameters and cannot flexibly address assembly errors; structural floating design relies on component precision, and in actual assembly, the floating mechanism often locks up and fails; final inspection screening can only identify problems but cannot provide a basis for corrective action at the assembly stage. Furthermore, a few studies have shown a correlation between bearing preload and assembly eccentricity and noise levels, but a repeatable process has not yet been established, and there is a lack of unified quantitative indicators for guidance. As a result, NVH consistency is poor in mass production of the same model of reducer, the optimization process relies on experience, and standardization is difficult to achieve. Summary of the Invention

[0004] In view of the above-mentioned problems, the present invention is proposed.

[0005] To solve the above technical problems, the present invention provides the following technical solution: a method for optimizing the vibration and noise of a planetary gearbox coaxial reducer, comprising: acquiring the initial assembly parameters of the reducer, collecting the load measurement signals of the planetary gears under the order sweep frequency condition of the reducer, converting the load measurement signals into equivalent meshing loads based on the calibration curve, calculating the load imbalance coefficient based on the equivalent meshing load, and taking the peak value of the load imbalance coefficient as the first evaluation index. Under the order sweep frequency condition, the radial acceleration and sound pressure signals of the shell are synchronously acquired, the side band ratio is calculated, and the peak value of the side band ratio is taken as the second evaluation index. Based on the first and second evaluation indicators, diagnostic triage is performed to determine the assembly parameters to be adjusted first, iterative adjustments are performed, and the final assembly parameters are output after the iteration is completed.

[0006] As a preferred embodiment of the vibration and noise optimization method for a planetary gearbox coaxial reducer described in this invention, the initial assembly parameters of the reducer include bearing preload parameters, floating mechanism parameters, positioning phase parameters, and meshing baseline parameters.

[0007] As a preferred embodiment of the vibration and noise optimization method for a planetary gear coaxial reducer described in this invention, the method of collecting load measurement signals of the planetary gears under the order sweep frequency condition of the reducer and converting the load measurement signals into equivalent meshing loads based on the calibration curve includes configuring a replaceable load measurement fixture for each planetary gear. Based on the calibration curve corresponding to the configured fixture, zero-point reset and temperature drift normalization are completed. The calibration curve is a function curve consisting of the correspondence between the load value output by the sensor and the actual load value after the fixture is installed. Perform an order frequency sweep, with the input speed increasing from the minimum speed to the maximum speed at a constant rate of increase, while simultaneously setting up a synchronization signal, and acquiring load measurement signals at a fixed sampling rate during the order frequency sweep process; The load measurement signal is back-calculated into an equivalent meshing load according to the calibration curve.

[0008] As a preferred embodiment of the vibration and noise optimization method for a planetary gearbox coaxial reducer described in this invention, the step of calculating the load imbalance coefficient based on the equivalent meshing load and taking the peak value of the load imbalance coefficient as the first evaluation index includes dividing the acceleration process of the input speed into multiple speed intervals, averaging the gear cycle and the planetary carrier cycle in each speed interval, and converting the equivalent meshing load into the nominal load in that speed interval. For each speed range, the load imbalance coefficient is obtained by dividing the maximum nominal load of each planetary gear in the range by the average nominal load. Based on the initial assembly parameters, select the typical operating speed range of the reducer, and take the peak value of the load imbalance coefficient within the typical operating speed range as the first evaluation index. .

[0009] As a preferred embodiment of the vibration and noise optimization method for a planetary gearbox coaxial reducer described in this invention, the calculation of the side band ratio and taking the peak value of the side band ratio as the second evaluation index includes: performing angular resampling on the radial acceleration and sound pressure signals of the housing to obtain the angular domain data of the radial acceleration and sound pressure signals of the housing; calculating the order spectrum of the angular domain data of the radial acceleration and sound pressure signals of the housing in each speed interval; locating the meshing order on the horizontal axis of the order spectrum and performing peak tracking of consecutive frames to obtain the main meshing amplitude. Extract the amplitude values ​​of the left and right bands and calculate the side-band ratio: ; in, Indicates the side band ratio; Indicates the amplitude on the left side; Indicates the amplitude on the right side; Indicates the main grid biting amplitude; The peak value of the side-band ratio within the typical operating speed range is taken as the second evaluation index. .

[0010] As a preferred embodiment of the vibration and noise optimization method for a planetary coaxial reducer described in this invention, the diagnostic diversion based on the first and second evaluation indicators includes setting a low threshold for the first evaluation indicator according to the initial assembly parameters of the reducer. and high threshold The low threshold of the second evaluation indicator and high threshold ; when When entering branch road 1, priority is given to all passengers; when ,and When entering branch 2, phase compensation takes priority; when ,and When entering branch 3, load equalization is performed first, followed by phase compensation; when ,and At that time, it enters branch 4 and performs light phase compensation; when ,and At that time, enter branch 5, skip the iteration adjustment, and output the final assembly parameters.

[0011] As a preferred embodiment of the vibration and noise optimization method for a planetary gearbox coaxial reducer described in this invention, the iterative adjustment includes setting the type of assembly parameter to be adjusted and the step size of the assembly parameter. The type of assembly parameter includes effective floating clearance, bearing preload target torque and positioning phase angle. The step size of the assembly parameter is set to a fixed value based on the initial assembly parameters of the reducer. During adjustment, the step size of the assembly parameter is increased or decreased by one step size each time. Iterative adjustments are made based on the results of diagnostic triage: For branch 1, only adjust the effective floating clearance and the bearing preload target torque; first increase the effective floating clearance, and retest the first evaluation index after each increase. If the first evaluation index decreases, retain the increase operation and increase the effective floating clearance again until the retest results are achieved. If the first evaluation index increases or remains unchanged, cancel the operation to increase the effective floating clearance and switch to adjusting the bearing preload target torque. Adjusting the bearing preload target torque specifically involves reducing the bearing preload target torque and retesting the first evaluation index. If the first evaluation index decreases, retain the increase operation and reduce the bearing preload target torque again until it is retested. If the first evaluation index increases or remains unchanged, then cancel the operation to reduce the bearing preload target torque. When the retest If the first evaluation index cannot be reduced, exit branch 1 and switch to diagnostic triage for reassessment; For branch 2, only the positioning phase angle is adjusted. The amplitude values ​​of the left and right bands are compared. If the amplitude value of the right band is greater than that of the left band, the positioning phase angle is decreased. If the amplitude value of the right band is less than that of the left band, the positioning phase angle is increased. The maximum value of the positioning phase angle adjustment is preset. After each adjustment of the positioning phase angle, the second evaluation index is re-measured. If the second evaluation index decreases, the adjustment operation is retained; if the second evaluation index increases or remains unchanged, the adjustment operation is cancelled. When the retest If the adjustment amount reaches the maximum value of the positioning phase angle, exit branch 2 and switch to diagnostic shunt for re-judgment; For branch 3, branch 1 is executed first until the exit condition of branch 1 is met. After branch 1 exits, the second evaluation index is retested. If... Then switch to branch 2 for adjustment, if Then exit branch 3 and switch to diagnostic triage for reassessment; For branch 4, the adjustment method is the same as for branch 2, but only the positioning phase angle is adjusted once and then retested. The adjustment operation is retained and exited from branch 4 to enter the diagnostic shunt. When the retest is performed... The adjustment operation is cancelled and the branch 4 is exited, then the diagnostic shunt is initiated.

[0012] The beneficial effects of this invention are as follows: The method of this invention can quickly identify uneven force distribution and meshing modulation intensity of planetary gears in short-range bench tests, and enter different process branches such as load sharing priority, phase compensation, or combined paths based on the judgment results. Each branch only performs fixed-amplitude operations on a single process parameter, such as floating clearance, bearing preload, or internal gear ring phase angle. The operation is immediately retested afterward to ensure process controllability and traceability. It can effectively separate and resolve load imbalance caused by assembly errors and side-band amplification caused by geometric eccentricity, fundamentally reducing the vibration and noise of the reducer. Attached Figure Description

[0013] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 The above is an overall flowchart of a method for optimizing the vibration and noise of a planetary gearbox coaxial reducer, provided in one embodiment of the present invention. Detailed Implementation

[0015] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0016] Example 1, referring to Figure 1 As an embodiment of the present invention, a method for optimizing the vibration and noise of a planetary gearbox coaxial reducer is provided, comprising: S1: Obtain the initial assembly parameters of the reducer, collect the load measurement signal of the planetary gear under the order sweep frequency condition of the reducer, convert the load measurement signal into equivalent meshing load based on the calibration curve, calculate the load imbalance coefficient according to the equivalent meshing load, and take the peak value of the load imbalance coefficient as the first evaluation index.

[0017] Furthermore, the initial assembly parameters of the reducer are obtained and documented to form a traceable initial assembly state and provide a unified reference for subsequent closed-loop optimization. Specifically, the baseline assembly of the reducer assembly is completed at a controlled workstation according to process specifications, and four key assembly parameters closely related to load distribution and mesh-side belt are quantitatively documented: First, the bearing preload parameters are established by using the torque-angle or equivalent displacement method to set the target preload value and record the matching shim thickness to ensure that the support stiffness and the initial force on the rolling elements are within a controllable range. Secondly, the floating mechanism parameters, including the determination and registration of the effective floating clearance, directly determine the ability of the floating release to offset the positioning deviation, and are a prerequisite for load distribution. Third, the positioning phase parameters are fixed by marking or coding the positioning phase reference angle of the internal gear ring relative to the housing, which serves as the angle reference for subsequent micro-eccentricity compensation, ensuring that fine-tuning at any position can be performed and reproduced with a relatively uniform reference. Fourth, the meshing baseline parameters are recorded, including the initial tooth flank clearance, to ensure that the meshing stiffness and return characteristics are within the design-permissible baseline range. All of the above parameters are written into the assembly card using a standardized unit of measurement and recording format and synchronized to the electronic database.

[0018] In this stage, the basic testing conditions, such as the short-range frequency sweep procedure and the initial oil temperature setting, are simultaneously solidified, but are not used as assembly parameters for adjustment. Through the above documentation, the influence of the load-sharing capacity, the angular reference values ​​used for micro-geometric correction, and the meshing baseline in the assembly process are made explicit and standardized, thereby providing a stable starting point for subsequent small-step adjustments, retest comparisons, and result convergence, avoiding criterion drift and optimization ineffectiveness caused by inconsistencies in the initial state.

[0019] To transform the actual interplanetary forces from an invisible state into quantifiable and measurable control quantities, load measurement signals of the planetary gears are acquired under the order sweep frequency condition after baseline assembly.

[0020] The process of acquiring load measurement signals of the planetary gears under the order-sweep frequency condition of the reducer and converting them into equivalent meshing loads based on the calibration curve specifically includes: Each planetary gear is equipped with a replaceable load measuring fixture; Based on the calibration curve corresponding to the configured fixture, zero-point reset and temperature drift normalization are completed. The calibration curve is a function curve consisting of the correspondence between the load value output by the sensor and the actual load value after the fixture is installed. Perform an order frequency sweep, with the input speed increasing from the minimum speed to the maximum speed at a constant rate of increase, while simultaneously setting up a synchronization signal, and acquiring load measurement signals at a fixed sampling rate during the order frequency sweep process; The load measurement signal is back-calculated into an equivalent meshing load according to the calibration curve.

[0021] Specifically, under controlled oil temperature conditions, the reducer is placed on a test bench, and the input shaft is driven according to a uniform short-range order sweep frequency procedure. The speed smoothly increases from the minimum speed to the maximum speed at a constant rate of increase, and the continuous speed increase process is divided into multiple speed ranges. Simultaneously, replaceable load measuring fixtures are installed at each planetary gear position, and an angle synchronization reference is established. The fixtures can be customized according to the product specifications. Planetary pin strain gauge bridge clamp (resistance strain gauges are pre-embedded in thin-walled clamping sleeves to form a Wheatstone bridge). Integrated force-measuring bearing (with a strain zone on the outer ring and an electrical signal output); Load-indicating film (color development under pressure, read from density-force value calibration curve).

[0022] To avoid altering the parts themselves, the fixtures are interchangeable with standard parts of the same size. When the measurement channel is limited, the alternation method is allowed to complete the recording of all planetary positions in two separate sessions, and the data from different batches are mapped to a unified phase through the angle synchronization reference.

[0023] To ensure the comparability of the quantification results with engineering standards, after the fixture is assembled, rapid calibration is first performed at two points: no load and light load, and the calibration number is recorded. During the frequency sweep, the oil temperature curve is simultaneously acquired to perform first-order temperature drift compensation on the signal.

[0024] To avoid frequency offset and unsteady-state artifacts introduced by speed increase, the acquired load measurement signal is converted into rotational domain data of the load measurement signal through angle resampling. A planetary carrier encoder is used as the main synchronization source, and phase alignment is achieved in conjunction with the primary tooth signal of the input shaft, ensuring that measurements at different planetary positions can be mapped to the same angular reference. Angle resampling refers to reconstructing the signal at equal intervals according to the shaft rotation angle, enabling stable identification of order characteristics under non-constant speed conditions.

[0025] It should be noted that rotational domain data refers to signal sequences resampled with the shaft rotation angle as the independent variable. During order sweep frequency analysis, the rotational speed continuously changes, and direct analysis in the time domain would cause frequency shifts, resulting in spectral broadening. By converting the signal to rotational domain data, it is possible to ensure that each rotational sampling point is evenly distributed, thus accurately characterizing meshing features at different rotational speeds and facilitating order analysis.

[0026] Subsequently, the rotational domain data of the load measurement signal was narrowband smoothed and outliers caused by instantaneous operating condition disturbances were removed to obtain the equivalent meshing load of each planetary gear within the speed range. To highlight the uniform load rather than the slight fluctuations within the elastic period between the teeth, gear period averaging and planetary carrier period averaging were performed for each speed range (planetary carrier period averaging is the average of the load waveforms repeated multiple times at the same planetary position with one revolution of the planetary carrier as the period, in order to suppress random noise and transient impacts), and the equivalent meshing load was converted into the nominal load of the i-th planetary gear at that speed.

[0027] After obtaining the nominal load within the same speed range, calculate the load imbalance coefficient: ; in, Indicates the load imbalance coefficient; i represents the planetary gear number; This indicates that the planetary gears are numbered from 1 to m. Take the maximum value; m represents the total number of planetary gears; This indicates that the planetary gears are numbered from 1 to m. Summation; This represents the nominal load of the i-th planetary gear.

[0028] The load imbalance coefficient curve is formed as the frequency sweep progresses. Considering that the low-speed region is susceptible to the effect of tooth backfill and the high-speed region is susceptible to the effects of oil-gas turbulence and structural mode superposition, the typical operating speed range of the reducer is selected based on the initial assembly parameters, and the peak value of the load imbalance coefficient within the typical operating speed range is taken as the first evaluation index. Meanwhile, the full curve is retained for subsequent comparison.

[0029] It should be noted that the load imbalance coefficient can directly quantify the load distribution among the planetary gears within a planetary gearbox transmission system. The ideal operating condition for a planetary gearbox reducer is that all planetary gears evenly distribute the transmitted torque, at which point the meshing forces of each planet are essentially equal, and the load imbalance coefficient is close to 1. However, in actual assembly and operation, factors such as manufacturing errors, improper clearance of the floating mechanism, bearing preload deviation, or slight eccentricity of the internal gear ring often lead to differences in the load borne by different planetary gears, resulting in some planets experiencing excessive force while others experience insufficient force. This imbalance not only causes periodic modulation of the meshing stiffness, amplifying the side-band energy of the meshing frequency and generating significant vibration noise, but also exacerbates wear and fatigue failure of local tooth surfaces, shortening the reducer's lifespan.

[0030] Therefore, the load imbalance coefficient, as a fundamental factor, can directly reflect the true balance of forces within a planetary system without relying on external acoustic or vibrational properties. A larger value indicates more severe load concentration, more pronounced meshing stiffness fluctuations, and a higher NVH risk for the system. Conversely, when the load imbalance coefficient is close to 1, it indicates that the load distribution is close to an ideal uniform state, resulting in better transmission stability and quietness.

[0031] Compared to criteria that rely solely on terminal noise levels or overall vibration amplitude, the load imbalance coefficient can reveal the underlying causes of noise formation earlier and more accurately, exhibiting higher sensitivity and guidance. Based on this characteristic, this invention sets the load imbalance coefficient as the first evaluation index in the assembly optimization closed loop, ensuring that subsequent small-step adjustments closely align with the system's load-sharing capacity, thereby fundamentally reducing noise sources.

[0032] S2: Under the order sweep frequency condition, the radial acceleration and sound pressure signals of the shell are collected synchronously, the side band ratio is calculated, and the peak value of the side band ratio is taken as the second evaluation index.

[0033] Furthermore, after synchronously acquiring the radial acceleration and sound pressure signals of the housing under the order sweep frequency condition, the radial acceleration and sound pressure signals of the housing are analyzed in the order domain to extract the side band features related to meshing.

[0034] Specifically, the radial acceleration and sound pressure signals of the shell collected by the test bench are converted into angular domain data of the radial acceleration and sound pressure signals of the shell under angular resampling conditions, so as to eliminate the frequency shift and spectral broadening caused by frequency sweep acceleration.

[0035] Within each velocity range, the order spectrum of the radial acceleration of the shell and the sound pressure signal in the angular domain is calculated. To suppress spectral leakage, a window function with a known equivalent noise bandwidth is used for windowing. Subsequently, the amplitude is adjusted by bandwidth normalization to ensure that the amplitudes of different velocity ranges are comparable. Spectral leakage refers to the energy diffusion phenomenon caused by finite-length data. If not adjusted, it will introduce systematic bias in the order amplitude.

[0036] Based on the tooth count and transmission ratio distribution, the meshing order is located on the horizontal axis (order axis) of the order spectrum, and peak tracking of consecutive frames is performed. The meshing order reflects the periodic energy concentration position of the inter-tooth meshing stiffness. Occasional false peaks are eliminated using amplitude continuity and phase smoothness constraints to obtain the stable trajectory of the meshing main peak. The amplitude of the stable trajectory of the meshing main peak is read as the main meshing amplitude. Subsequently, the energy of the left and right sidebands is extracted in the equidistant neighborhoods on both sides of the meshing order. The sidebands are the amplitude / frequency modulation results generated by low-frequency modulation (such as carrier rotation or geometric eccentricity) on the high-frequency meshing process. To improve noise immunity, based on the energy of the left and right sidebands, the amplitude of the left and right sidebands is obtained in the neighborhood of the sidebands using narrowband energy integration or peak-mean fusion method. Frequency domain gain correction is performed on the sensor frequency response differences to ensure consistent data from different measurement points and different batches.

[0037] The sideband ratio is defined as the ratio of the sum of the amplitudes of the left and right sidebands to the amplitude of the main peak of the meshing, expressed as: ; in, Indicates the side band ratio; Indicates the amplitude on the left side; Indicates the amplitude on the right side; The main meshing amplitude is represented; the peak value of the side belt ratio within the typical operating speed range is taken as the second evaluation index. .

[0038] The sideband ratio can directly reflect the degree of amplitude modulation of the meshing stiffness periodic energy by low-frequency modulation, and is therefore highly correlated with the intensity of hum / whistle related to auditory perception.

[0039] It should be noted that the sideband ratio is set as the second evaluation index, complementing the load imbalance coefficient. The appearance of the sideband is essentially a manifestation of low-frequency modulation. When the planetary gear load distribution is uneven, the internal gear ring has slight eccentricity, or the bearing preload is improper, periodic fluctuations are introduced during gear meshing, causing the high-frequency meshing signal to be modulated by low frequencies, thus producing symmetrical or asymmetrical sidebands on both sides of the main frequency. The magnitude of the sideband ratio directly reflects the modulation intensity: a large sideband ratio indicates that the meshing force is subject to significant periodic disturbances, and noise energy diffuses to the low-frequency side, resulting in a noticeable humming or howling sound; while a small sideband ratio indicates concentrated meshing energy, a stable system meshing process, and improved noise performance.

[0040] Unlike the load imbalance coefficient, which tends to reveal the root causes of internal force distribution problems, the side-band ratio more directly reflects the externally perceived vibration and noise performance. Therefore, this invention sets the side-band ratio as a secondary evaluation index, serving as a result-based supplement to the load imbalance coefficient: in assembly optimization, improvements in the load imbalance coefficient do not always translate directly into noise reduction; in such cases, the side-band ratio can serve as the final basis for judging whether the acoustic improvement target has been achieved. Furthermore, the side-band ratio is sensitive to modulation type and degree, helping to distinguish between different imbalance modes such as load sharing deviation and geometric eccentricity.

[0041] In summary, the side-band ratio, as the second evaluation index, serves several purposes: first, it establishes a direct link between internal stress changes and external noise performance; second, it provides a direct acoustic criterion for the convergence of assembly optimization; and third, it indicates the need for further micro-eccentricity compensation or phase adjustment when the load imbalance coefficient is acceptable but the noise level is still too high. The load imbalance coefficient and the side-band ratio respectively act as the root cause and the result, forming a complementary dual-index system within the closed-loop optimization system constructed in this invention.

[0042] S3: Based on the first and second evaluation indicators, perform diagnostic triage, determine the assembly parameters to be adjusted first, perform iterative adjustment, and output the final assembly parameters after the iteration is completed.

[0043] Furthermore, diagnostic traffic diversion is performed based on the first and second evaluation indicators, and the diagnostic traffic diversion results are used as execution instructions for subsequent adjustments. A low threshold for the first evaluation indicator is set according to the initial assembly parameters of the reducer. and high threshold The low threshold of the second evaluation indicator and high threshold The first evaluation index reflects the degree of force distribution among the planets; the larger the value, the worse the load-bearing capacity. The second evaluation index reflects the intensity of low-frequency modulation during meshing; the larger the value, the more obvious the side-band amplification and the worse the listening experience.

[0044] when When the load is severely unbalanced, the circuit enters branch 1, prioritizing load sharing. Severe imbalance causes a reduction in meshing stiffness with rotation angle, which is the root cause of side band amplification. If phase compensation is performed first, it may mask the root cause and hinder convergence. Therefore, in this branch, only small adjustments are allowed around the adjustable process parameters of floating and preload, such as adjusting the effective floating clearance to unlock floating release errors, or fine-tuning bearing preload to avoid locking the floating mechanism. Any phase / micro-eccentricity compensation is prohibited.

[0045] when ,and At this point, the load distribution is deemed acceptable, but the side band is severely amplified, leading to branch 2, where phase compensation is prioritized. Since the load is now more evenly distributed, the side band anomaly is more likely caused by slight eccentricity of the internal gear ring or assembly phase misalignment, falling under the category of geometric-phase problems. Correction should be directly applied to the positioning phase. Therefore, only slight eccentricity / phase compensation is performed to minimize disturbance to the established load-sharing state, and a retest is conducted after fine-tuning a single wheel. Verify the inhibitory effect.

[0046] when ,and At that time, it was determined to be a moderate imbalance in load sharing accompanied by sideband amplification, and the circuit entered branch 3, where load sharing was performed first, followed by phase compensation. Moderate imbalance is sufficient to induce a noticeable sideband amplification, but its sensitivity is greater for improving load sharing; if it is not reduced first... Phase compensation often exhibits instability or repetition. Therefore, within this branch, it is first implemented in small steps. Reduce to Next, let's return to the diagnostic triage, based on the new... Decide whether to switch to branch 2 for light phase correction to ensure monotonic convergence of the optimized path.

[0047] when ,and When the load is deemed acceptable and the side band amplification is moderate, the signal enters branch 4 for light phase compensation. If the side band is too high but not reaching the severe threshold, small-step phase fine-tuning can be used to verify the existence of slight eccentricity / phase shift at minimal cost, avoiding excessive disturbance to the existing assembly state. If a single-round fine-tuning... Down to The following steps will exit the closed loop according to the diagnostic triage and release rules.

[0048] when ,and When the load sharing and side belt are both within the acceptable range, enter branch 5, skip the iteration adjustment, and output the final assembly parameters.

[0049] It should be noted that some interval combinations do not form new branch determination rules separately. This is because these combinations have a very low probability of occurring in the actual assembly and operation of planetary gear reducers, or their performance can be covered by existing branches, so there is no need to set up redundant branches.

[0050] For example, when At any time, regardless The values, regardless of their magnitude, all fall under the category of severe load imbalance without amplification of the side band. However, in reality, severe imbalance inevitably leads to a strong modulation of meshing stiffness with rotation angle, and the side band energy usually increases significantly. Maintaining low values ​​is almost impossible, and even if it does occur, it is usually due to measurement errors or operating condition disturbances. Therefore, such cases are all categorized under the load-sharing priority branch, and the anomalies can be eliminated through repeated testing and verification.

[0051] For example, when ,and Extremely high values ​​often indicate that the measurement channel is distorted or subject to environmental noise interference, rather than reflecting the true assembly status. Such cases should trigger a retest mechanism, rather than being treated as a separate branch.

[0052] Therefore, this invention does not establish separate branches for these atypical intervals, but instead handles them through a retest verification mechanism and hysteresis band control. This design avoids complicating the decision logic while ensuring the stability and engineering operability of the assembly optimization process. In other words, the five branches listed in the diagnostic triage cover the main performance intervals under actual assembly conditions, which can handle both high-probability problem scenarios and low-probability or measurement anomaly scenarios through anomaly detection methods, making the optimization process both comprehensive and efficient.

[0053] The diagnostic branch performs the decision-making function, outputting branch codes and the set of allowed adjustable objects, and specifying the exit threshold. The iterative adjustment performs the execution function, performing single-factor small-step adjustments based on the branches and thresholds given by the diagnostic branch. After each round of adjustment, the new first and second evaluation indicators are retested within the same representative speed window, and the results are sent back to the diagnostic branch. The diagnostic branch uses this information to determine whether to continue iterating along the current branch, whether to switch to a subsequent branch, or whether to enter branch 5 if the exit conditions are met.

[0054] Furthermore, iterative adjustments are performed based on the diagnostic diversion results. The types of assembly parameters to be adjusted and the step size of assembly parameters are set. The types of assembly parameters include effective floating clearance, bearing preload target torque and positioning phase angle. The step size of assembly parameters is set to a fixed value based on the initial assembly parameters of the reducer. During adjustment, the step size of assembly parameters is increased or decreased by one step size each time.

[0055] It should be noted that bearing preload can be adjusted in two ways: firstly, using the torque-angle method, by changing the target torque for bolt tightening; secondly, using the shim method, by replacing shims of different thicknesses. Both methods are used to control the bearing preload and support stiffness; therefore, the method description only uses the target bearing preload torque to represent the bearing preload adjustment amount. In practical applications, these two methods will not appear simultaneously as independent adjustment amounts; instead, one will be selected based on the process path used in the assembly line.

[0056] For branch 1, only adjust the effective floating clearance and the bearing preload target torque; first increase the effective floating clearance, and retest the first evaluation index after each increase. If the first evaluation index decreases, retain the increase operation and increase the effective floating clearance again until the retest results are achieved. If the first evaluation index increases or remains unchanged, cancel the operation to increase the effective floating clearance and switch to adjusting the bearing preload target torque. Adjusting the bearing preload target torque specifically involves reducing the bearing preload target torque and retesting the first evaluation index. If the first evaluation index decreases, retain the increase operation and reduce the bearing preload target torque again until it is retested. If the first evaluation indicator increases or remains unchanged, then cancel the operation to reduce the bearing preload target torque; when the retest is performed... If the first evaluation index cannot be reduced, exit branch 1 and switch to diagnostic triage for reassessment; The reason why the first evaluation index can be improved by increasing the effective floating clearance is that the function of the floating mechanism is to release manufacturing and positioning errors, so that the sun gear / planet gear can automatically find the optimal position around the theoretical center. When the effective floating clearance is too small or the assembly error is stuck, individual planet gears will bear higher meshing loads for a long time, and the meshing stiffness will be more strongly restricted with the rotation angle, thus increasing the first evaluation index and driving the second evaluation index to rise.

[0057] When the effective floating clearance reaches the model's permissible upper limit or the improvement to the first evaluation indicator is insufficient, other assembly parameters are adjusted. The mechanism is that excessive preload increases support stiffness and inhibits the floating mechanism's adaptive posture, leading to a phenomenon known as "locked-up floating." Appropriately reducing preload or shim thickness releases minor assembly stress without compromising bearing life and stability, further improving load distribution among planets and fundamentally lowering the first evaluation indicator. Each parameter change is immediately retested. If the first evaluation indicator does not decrease, the operation is canceled and the current path terminated to prevent further accumulation in the wrong direction.

[0058] For branch 2, only the positioning phase angle is adjusted. The amplitude values ​​of the left and right bands are compared. If the amplitude value of the right band is greater than that of the left band, the positioning phase angle is decreased; if the amplitude value of the right band is less than that of the left band, the positioning phase angle is increased. A maximum adjustment value for the positioning phase angle is preset. After each adjustment of the positioning phase angle, the second evaluation index is retested. If the second evaluation index decreases, the adjustment operation is retained; if the second evaluation index increases or remains unchanged, the adjustment operation is canceled. When the retest reaches... If the adjustment amount reaches the maximum value of the positioning phase angle, exit branch 2 and switch to diagnostic shunt for re-judgment; The reason why the second evaluation index can be suppressed by rotating the positioning phase angle is that the ±1st order side bands on both sides of the meshing main peak are essentially derived from the amplitude / frequency modulation of high-frequency meshing by low-frequency modulation (carrier fundamental order). Assembly geometric eccentricity or internal gear ring positioning phase offset will form a modulation source with a fixed phase. By rotating the internal gear ring relative to the housing in a directional manner at a fixed step distance, the phase relationship between the eccentricity error and the meshing force vector can be changed. Without changing the distance between the part body and the center, the modulation term can be canceled or weakened, thereby reducing the energy of the side bands and causing the second evaluation index to decrease.

[0059] The step size of the positioning phase angle comes from the controllable resolution of the commonly used rotatable positioning bushing / clearance positioning pin and the minimum reproducible angle allowed by the hole system arrangement. The maximum value of the positioning phase angle adjustment avoids poor fit between the secondary positioning of the hole system and the meshing surface of the seal.

[0060] For branch 3, branch 1 is executed first until the exit condition of branch 1 is met. After branch 1 exits, the second evaluation index is retested. If... Then switch to branch 2 for adjustment, if Then exit branch 3 and switch to diagnostic triage for reassessment.

[0061] The load sharing problem is an upstream root cause of side-band amplification: if the first evaluation index is not first reduced to the qualified region, and the positioning phase angle is directly adjusted, the modulation source is still there, and the phase only undergoes a small-amplitude cancellation on high-energy modulation, often resulting in slow convergence or even repetitive situations. Therefore, this invention first uses a load sharing priority branch approach to... During this process, the permissible range of tooth flank clearance and bearing temperature rise are continuously monitored. After the load sharing target is achieved, the positioning phase angle is adjusted according to the phase compensation priority branch method to achieve a significant decrease in the second evaluation index with relatively smaller movements. This sequence design ensures the monotonicity and repeatability of the optimization path, first eliminating the modulation intensity and then correcting the modulation phase.

[0062] For branch 4, the adjustment method is the same as for branch 2, but only the positioning phase angle is adjusted once and then retested. The adjustment operation is retained and exited from branch 4 to enter the diagnostic shunt. When the retest is performed... The adjustment operation is cancelled and the branch 4 is exited, then the diagnostic shunt is initiated.

[0063] This path involves adjusting the positioning phase angle only once and then re-measuring. The reason it's only done once is because... At this time, side belt deviation is often caused by slight positioning angle deviation or cumulative tolerance of the hole system. It is characterized by slight eccentricity and light adjustment. A single rotation adjustment is sufficient to determine whether this type of deviation exists and whether it is sensitive to noise. If the angle is not improved, the operation is cancelled to avoid unnecessary disturbance to the already achieved load distribution and meshing clearance. This lightweight strategy minimizes assembly cycle time and risk while retaining the ability to quickly handle minor phase issues.

[0064] Through this step, load-sharing capacity and side-band suppression are improved in a perceptible, controllable, and reproducible manner under the same test caliber: when the load imbalance coefficient decreases, the angular modulation of meshing stiffness is weakened, and the side-band ratio decreases accordingly; when the load imbalance coefficient is within a reasonable range but the side-band ratio is still too high, the side-band energy can be significantly reduced by adjusting the positioning phase angle by a small angle. Finally, the assembly parameters and the corresponding load imbalance coefficient and side-band ratio retest results are solidified into the NVH assembly fingerprint of this part, which is used to guide and correct the assembly process of the planetary coaxial reducer, fundamentally reducing noise.

[0065] In summary, this invention proposes an assembly optimization method for vibration and noise in planetary gearbox coaxial reducers. By establishing initial data on key parameters such as effective floating clearance, bearing preload or shim thickness, and internal gear ring positioning phase during the baseline assembly stage, and extracting two evaluation indices—load imbalance coefficient and side band ratio—under bench sweep conditions, a quantitative characterization of the interplanetary load distribution state and meshing modulation intensity is achieved.

[0066] Based on this, the present invention utilizes the combined relationship between the load imbalance coefficient and the side band ratio for branch determination, entering different optimization branches such as load sharing priority, phase compensation priority, joint path, or lightweight path, and then retesting and iterating round by round through small-step, single-variable controllable operations. The entire process ensures a closed-loop logic of determination-execution-redetermination, enabling assembly optimization to form a causal chain from the root cause (load sharing capacity) to the result (side band performance), with a clear and repeatable convergence path.

[0067] The method of this invention not only overcomes the shortcomings of traditional processes that rely on experience-based listening or single final inspections, but also transforms the originally invisible load-sharing state into quantifiable and repeatable indicators, establishing a standardized process that can be executed under mass production cycles. Through this method, the vibration and noise levels of planetary gear reducers can be significantly reduced without altering the component design, improving assembly consistency and reliability. Furthermore, it provides a traceable data foundation and process fingerprint for subsequent process solidification and mass production, demonstrating significant technical benefits and application prospects.

[0068] If the above functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0069] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-including system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device.

[0070] More specific examples of computer-readable media (a non-exhaustive list) include: electrical connections (electronic devices) having one or more wires, portable computer disk drives (magnetic devices), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Furthermore, computer-readable media can even be paper or other suitable media on which the program can be printed, because the program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in computer memory.

[0071] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0072] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for optimizing the vibration and noise of a planetary gearbox coaxial reducer, characterized in that, include: The initial assembly parameters of the reducer are obtained, the load measurement signals of the planetary gears are collected under the order sweep frequency condition, the load measurement signals are converted into equivalent meshing loads based on the calibration curve, the load imbalance coefficient is calculated based on the equivalent meshing load, and the peak value of the load imbalance coefficient is taken as the first evaluation index. Under the order sweep frequency condition, the radial acceleration and sound pressure signals of the shell are synchronously acquired, the side band ratio is calculated, and the peak value of the side band ratio is taken as the second evaluation index. Based on the first and second evaluation indicators, diagnostic triage is performed to determine the assembly parameters to be adjusted first, iterative adjustments are performed, and the final assembly parameters are output after the iteration is completed.

2. The vibration and noise optimization method for a planetary gearbox coaxial reducer as described in claim 1, characterized in that: The initial assembly parameters of the reducer include bearing preload parameters, floating mechanism parameters, positioning phase parameters, and meshing baseline parameters.

3. The vibration and noise optimization method for a planetary gearbox coaxial reducer as described in claim 2, characterized in that: The load measurement signal of the planetary gears under the order sweep frequency condition of the acquisition reducer is converted into equivalent meshing load based on the calibration curve, including configuring a replaceable load measurement fixture for each planetary gear. Based on the calibration curve corresponding to the configured fixture, zero-point reset and temperature drift normalization are completed. The calibration curve is a function curve consisting of the correspondence between the load value output by the sensor and the actual load value after the fixture is installed. Perform an order frequency sweep, with the input speed increasing from the minimum speed to the maximum speed at a constant rate of increase, while simultaneously setting up a synchronization signal, and acquiring load measurement signals at a fixed sampling rate during the order frequency sweep process; The load measurement signal is back-calculated into an equivalent meshing load according to the calibration curve.

4. The vibration and noise optimization method for a planetary gearbox coaxial reducer as described in claim 3, characterized in that: The step of calculating the load imbalance coefficient based on the equivalent meshing load and taking the peak value of the load imbalance coefficient as the first evaluation index includes dividing the acceleration process of the input speed into multiple speed intervals, averaging the gear cycle and the planetary carrier cycle in each speed interval, and converting the equivalent meshing load into the nominal load in that speed interval. For each speed range, the load imbalance coefficient is obtained by dividing the maximum nominal load of each planetary gear in the range by the average nominal load. Based on the initial assembly parameters, select the typical operating speed range of the reducer, and take the peak value of the load imbalance coefficient within the typical operating speed range as the first evaluation index. .

5. The vibration and noise optimization method for a planetary gearbox coaxial reducer as described in claim 4, characterized in that: The calculation of the side band ratio, taking the peak value of the side band ratio as the second evaluation index, includes: resampling the radial acceleration and sound pressure signals of the shell at an angle to obtain the angular domain data of the radial acceleration and sound pressure signals of the shell; calculating the order spectrum of the angular domain data of the radial acceleration and sound pressure signals of the shell in each velocity interval; locating the meshing order on the horizontal axis of the order spectrum and performing peak tracking of consecutive frames to obtain the main meshing amplitude. Extract the amplitude values ​​of the left and right bands and calculate the side-band ratio: ； in, Indicates the side band ratio; Indicates the amplitude on the left side; Indicates the amplitude on the right side; Indicates the main grid biting amplitude; The peak value of the side-band ratio within the typical operating speed range is taken as the second evaluation index. .

6. The vibration and noise optimization method for a planetary gearbox coaxial reducer as described in claim 5, characterized in that: The diagnostic triage based on the first and second evaluation indicators includes setting a low threshold for the first evaluation indicator according to the initial assembly parameters of the reducer. and high threshold The low threshold of the second evaluation indicator and high threshold ; when When entering branch road 1, priority is given to all passengers; when ,and When entering branch 2, phase compensation takes priority; when ,and When entering branch 3, load equalization is performed first, followed by phase compensation; when ,and At that time, it enters branch 4 and performs light phase compensation; when ,and At that time, enter branch 5, skip the iteration adjustment, and output the final assembly parameters.

7. The vibration and noise optimization method for a planetary gearbox coaxial reducer as described in claim 6, characterized in that: The iterative adjustment includes setting the type of assembly parameter to be adjusted and the step size of the assembly parameter. The assembly parameter type includes effective floating clearance, bearing preload target torque and positioning phase angle. The assembly parameter step size is set to a fixed value based on the initial assembly parameters of the reducer. During adjustment, the assembly parameter step size is increased or decreased by one step size each time. Iterative adjustments are made based on the results of diagnostic triage: For branch 1, only adjust the effective floating clearance and the bearing preload target torque; first increase the effective floating clearance, and retest the first evaluation index after each increase. If the first evaluation index decreases, retain the increase operation and increase the effective floating clearance again until the retest results are achieved. If the first evaluation index increases or remains unchanged, cancel the operation to increase the effective floating clearance and switch to adjusting the bearing preload target torque. Adjusting the bearing preload target torque specifically involves reducing the bearing preload target torque and retesting the first evaluation index. If the first evaluation index decreases, retain the increase operation and reduce the bearing preload target torque again until it is retested. If the first evaluation index increases or remains unchanged, then cancel the operation to reduce the bearing preload target torque. When the retest If the first evaluation index cannot be reduced, exit branch 1 and switch to diagnostic triage for reassessment; For branch 2, only the positioning phase angle is adjusted. The amplitude values ​​of the left and right bands are compared. If the amplitude value of the right band is greater than that of the left band, the positioning phase angle is decreased. If the amplitude value of the right band is less than that of the left band, the positioning phase angle is increased. The maximum value of the positioning phase angle adjustment is preset. After each adjustment of the positioning phase angle, the second evaluation index is re-measured. If the second evaluation index decreases, the adjustment operation is retained; if the second evaluation index increases or remains unchanged, the adjustment operation is cancelled. When the retest If the adjustment amount reaches the maximum value of the positioning phase angle, exit branch 2 and switch to diagnostic shunt for re-judgment; For branch 3, branch 1 is executed first until the exit condition of branch 1 is met. After branch 1 exits, the second evaluation index is retested. If... Then switch to branch 2 for adjustment, if Then exit branch 3 and switch to diagnostic triage for reassessment; For branch 4, the adjustment method is the same as for branch 2, but the positioning phase angle adjustment is performed only once and a retest is conducted. The adjustment operation is retained and exited from branch 4 to enter the diagnostic shunt. When the retest is performed... The adjustment operation is cancelled and the branch 4 is exited, and the diagnostic shunt is initiated.

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