Method and device for determining load on bearing of gear of transmission, and transmission having device
By detecting the acceleration signal of the transmission device and using filtering and transformation techniques to extract the gear meshing frequency, the problem of early identification of bearing load changes is solved, enabling early prediction of faults and reducing maintenance workload and equipment downtime risk.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHAFA FRIEDRICH SCHAFFEN CO LTD
- Filing Date
- 2025-10-14
- Publication Date
- 2026-04-17
AI Technical Summary
Existing technologies make it difficult to identify potential load changes in transmission device gear bearings in a timely manner, resulting in a large amount of maintenance work and potential equipment downtime.
By detecting the acceleration signal of the transmission device, and using techniques such as filtering, Hilbert transform, and Fourier transform, the gear meshing frequency and amplitude signals are extracted. Combined with reference values, the bearing load is identified, and faults are predicted early.
This enables early identification of bearing load changes, reduces maintenance workload, prevents prolonged equipment downtime, and ensures safe operation.
Smart Images
Figure CN121877397A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a method, an apparatus, and a transmission device having the apparatus for knowing the load on the bearing of a gear in a transmission device. Background Technology
[0002] Methods for detecting bearing failures are known from the prior art. These methods include determining the frequencies associated with failures of the bearing's inner or outer ring, rolling elements, or cage. The frequencies determined in this context are also referred to as bearing failure frequencies. Summary of the Invention
[0003] The first aspect relates to a method for determining the load on the bearings of a gear in a transmission device.
[0004] The transmission device can be any type of transmission device that provides gear meshing. For example, the transmission device can be a planetary gear transmission. The gears of the transmission device can mesh with another gear in the same transmission device. The bearings of the gears can depend on the type of transmission device and the operating conditions. In a planetary gear transmission, the gear can be a planetary gear of the transmission. In this case, the planetary gear can mesh with, for example, the ring gear of the transmission. The bearings of the gears can be planetary gear bearings. The bearings can be, for example, roller bearings, plain bearings, needle roller bearings, or ball bearings.
[0005] The load on a bearing can indicate damage to that bearing. Therefore, the load can indicate a failure of that bearing. The load on a bearing can indicate damage to that bearing. Therefore, the load can indicate that the bearing is about to fail. The load can describe the deformation of the gear, and therefore can describe the deviation of the force acting on the reference force in gear meshing.
[0006] The method includes: determining the gear meshing frequency at the gear meshing point of the gears in the transmission device based on the acceleration signal of the transmission device.
[0007] Gear meshing frequency describes the vibration caused by gear meshing. It can also describe the quality of gear meshing, such as the quality of the forces acting within it. Gear meshing frequency can include the carrier frequency, upper sideband, and lower sideband.
[0008] Acceleration signals can include the acceleration of vibrations in a transmission device. An acceleration signal can represent the acceleration of bearing vibrations. Acceleration signals can be detected using sensors. Acceleration signals can be acquired. This acquisition can include reading, for example, from a database.
[0009] The method includes determining the bearing load based on the known gear meshing frequency and reference values.
[0010] The known gear meshing frequency of the bearing can indicate the load. For example, variations in bearing operation may cause a deviation between the known gear meshing frequency and a reference value. This deviation can indicate the bearing's unbalanced behavior. Therefore, this deviation can indicate the load on the bearing. The degree of this deviation can indicate the degree of the load.
[0011] A reference value can describe the gear meshing frequency of a bearing in an undamaged state. For example, a reference value can be obtained from a database. The reference value can be detected, for example, during continuous monitoring, at the start of monitoring, and stored in a readable manner, such as in a database. In this way, gear meshing frequencies varying due to gear engagement can be detected, and this gear meshing frequency can be used as a reference value for continuous measurement.
[0012] This method allows for the detection and handling of vibrations, enabling the assessment of bearing loads. Therefore, it provides the possibility of detecting vibrations in bearings and thereby identifying bearing failures. These loads may occur before physical damage has occurred on the bearing, and therefore the pulses of this damage are outside the bearing failure frequency range. The frequency range generated by this load may be below the bearing's rotational frequency. Therefore, this method is particularly effective in detecting and considering potentially harmful vibrations in the low-frequency range, and in detecting and considering these potentially harmful vibrations early when the bearing load is known. This allows for the early identification of loads on the bearing that may indicate impending failure. Consequently, this method reduces maintenance workload because bearings can be replaced earlier, thus enabling safe operation and optimal gear meshing.
[0013] In one embodiment, the acceleration signal may be the acceleration of vibration on the housing of the transmission device.
[0014] The acceleration of vibration on the housing of the transmission device can therefore be measured at a certain point on the housing, such that the measurement represents the acceleration of vibration at the gear meshing point. The acceleration of vibration on the housing of the transmission device can therefore be measured at a certain point on the housing, such that the measured signal represents the acceleration of vibration at the gear meshing point as purely as possible. "Pure" here can be understood as having little or no interference. "Pure" can also be understood as having minimal superimposed noise signals. It can be envisioned that the measurement is performed at or near the gear meshing point.
[0015] This allows for the acquisition of a representative measurement of the acceleration of vibrations at the gear meshing point.
[0016] In one embodiment, the gear meshing may be the meshing of a planetary gear in a planetary gear transmission with a gear in the ring gear of the planetary gear transmission, and the bearing may be a bearing of the planetary gear.
[0017] Knowing the load on the planetary gear bearings and thus identifying impending failures can prevent prolonged downtime of planetary gear drives.
[0018] In one implementation, knowing the gear meshing frequency may include filtering the acceleration signal.
[0019] The filter can be a frequency filter, such as a bandpass filter. The relevant frequency can depend on the transmission mechanism. Therefore, the filtering range of the acceleration signal can vary depending on the transmission mechanism used. This makes it possible to perform variable filtering of the acceleration signal based on the transmission mechanism used.
[0020] In this way, the acceleration signal can be reduced to the relevant frequency. This reduces the amount of acceleration signal data that needs further processing, thus speeding up the process of further data processing.
[0021] In addition, knowing the gear meshing frequency can include decomposing the filtered acceleration signal into phase and amplitude signals.
[0022] This allows the acceleration signal to be converted into an analytical form. The decomposed acceleration signal can have a combination of amplitude and phase information. The amplitude information can be an amplitude signal. The phase information can be a phase signal. For example, the Hilbert transform can be used to decompose the acceleration signal. Thus, frequencies that are difficult to detect in the time domain due to noise superimposed on the acceleration signal can become detectable by transforming the filtered acceleration signal to the frequency domain.
[0023] In addition, obtaining the gear meshing frequency can include extracting the amplitude signal based on the decomposed acceleration signal.
[0024] As described above, the decomposed acceleration signal exists as a combination of phase and amplitude signals. These two pieces of information are correlated with each other in a separable manner through decomposition. For example, the amplitude signal can be extracted by knowing the absolute value of the decomposed acceleration signal. The amplitude signal can indicate the maximum deviation of the acceleration signal and thus describe the intensity of the acceleration of the vibration at the gear meshing point.
[0025] In addition, knowing the gear meshing frequency may include knowing the spectrum of the extracted amplitude signal.
[0026] This step can be performed, for example, using Fourier transform or Fast Fourier transform. This decomposes the extracted amplitude signal into frequency components, allowing us to determine the distribution of the frequency components of the amplitude signal.
[0027] In addition, knowing the gear meshing frequency can include knowing the gear meshing frequency based on the known spectrum.
[0028] The obtained spectrum can describe which frequencies and what intensities exist in the extracted amplitude signal. From this, the gear meshing frequency can be determined.
[0029] In one implementation, filtering the acceleration signal can be done by bandpass filtering. Decomposing the filtered acceleration signal into phase and amplitude signals can be done by performing a Hilbert transform on the filtered acceleration signal. Extracting the amplitude signal based on the decomposed acceleration signal can be done by determining the absolute value of the decomposed acceleration signal. Obtaining the spectrum can be done by applying a Fast Fourier Transform based on this absolute value. Determining the gear meshing frequency based on the obtained spectrum can be done by using the output of the Fast Fourier Transform.
[0030] In one embodiment, filtering an acceleration signal may include: obtaining the effective value signal of the acceleration signal and filtering the effective value signal.
[0031] The RMS signal can be the effective value of the acceleration signal. Therefore, the RMS signal can describe the average power of the acceleration signal. The RMS signal can be obtained using the root mean square (RMS). Using the RMS signal can help suppress noise.
[0032] In one implementation, before the step of extracting the amplitude signal, a signal preparation step can be performed by adding the filtered acceleration signal to the decomposed acceleration signal.
[0033] Due to this decomposition, the signal may contain noise components that could degrade signal quality. Adding the filtered acceleration signal to the decomposed acceleration signal during signal preparation can suppress or at least reduce noise. Adding the filtered acceleration signal to the decomposed acceleration signal results in an increase in signal strength. This also improves the signal-to-noise ratio (SNR). This enhances the amplitude signal. Therefore, the amplitude signal can be extracted based on the sum of these two added signals. This improves signal quality. By improving signal quality, the extracted amplitude signal can exist with a quality that improves the accuracy of gear meshing frequency.
[0034] The second aspect relates to an apparatus configured to perform the steps of the method according to the first aspect. Other corresponding features, embodiments, and advantages can be derived from the description of the first aspect. Conversely, the features, embodiments, and advantages of the second aspect also represent the features, embodiments, and advantages of the first aspect.
[0035] The third aspect relates to a transmission device having an apparatus configured to perform the steps of the method according to the first aspect, wherein the transmission device includes a first gear and a second gear, wherein the first gear and the second gear are in gear meshing, and wherein the transmission device includes at least one bearing for the first gear. Other corresponding features, embodiments, and advantages can be derived from the descriptions of the first and second aspects. Conversely, the features, embodiments, and advantages of this third aspect also represent the features, embodiments, and advantages of the first and second aspects. Attached Figure Description
[0036] Figure 1 A flowchart of the method according to the implementation is shown; and
[0037] Figure 2 A schematic diagram of the transmission device is shown. Detailed Implementation
[0038] Figure 1 A flowchart of the method according to the implementation is shown.
[0039] The method includes: determining the gear meshing frequency S1 at the gear meshing 8 of the gear 4 in the transmission device 1 based on the acceleration signal of the transmission device 1.
[0040] The step S1 of obtaining the gear meshing frequency includes: filtering the acceleration signal S11.
[0041] exist Figure 1 In the embodiment shown, filtering the acceleration signal S11 is bandpass filtering. The filtering range of the bandpass filter depends on the transmission device 1 used. In the present case, the bandpass filter filters frequencies in the range of 100 Hz to 1500 Hz. Therefore, only this frequency range is considered for further signal processing. Filtering the acceleration signal S11 includes: obtaining the effective value signal of the acceleration signal S111 and filtering the effective value signal S112.
[0042] The method further includes: decomposing the filtered acceleration signal into a phase signal and an amplitude signal S12; and extracting the amplitude signal based on the decomposed acceleration signal S13. The method further includes: obtaining the spectrum of the extracted amplitude signal S14; and obtaining the gear meshing frequency based on the obtained spectrum S15.
[0043] Decomposing the filtered acceleration signal into phase and amplitude signals (S12) involves performing a Hilbert transform on the filtered acceleration signal. Before extracting the amplitude signal (S13), a signal preparation step (S130) is performed by adding the filtered and decomposed acceleration signals. This improves the signal quality. The signal preparation step by adding (S130) is optional, as shown in... Figure 1 As seen in the flowchart, the dashed arrows between steps S12 and S13 indicate the following: S13 involves extracting the amplitude signal from the decomposed acceleration signal by determining the absolute value of the decomposed acceleration signal. This yields the envelope of the decomposed acceleration signal, which describes the impulse events of the decomposed acceleration signal. S14 involves applying a Fast Fourier Transform (FFT) based on this absolute value to obtain the frequency component distribution. S15 involves determining the gear meshing frequency based on the obtained spectrum, using the output of the FFT. Therefore, the frequency component distribution is used to determine the gear meshing frequency.
[0044] The method further includes determining the bearing load S2 based on the known gear meshing frequency and a reference value. The reference value is the known gear meshing frequency, which is detected at the start of operation of the transmission device 1. The reference value is then stored in a database in a readable manner. When the bearing load S2 is determined, the known gear meshing frequency is compared with the reference value. If a deviation is confirmed in this case, it indicates abnormal bearing behavior and therefore indicates bearing damage. In this case, the degree of deviation is an indicator of the severity of the load.
[0045] Figure 2 A schematic diagram of a transmission device 1 in the form of a planetary gear transmission device 11 is shown.
[0046] The planetary gear transmission 11 includes a device 2 configured to perform the steps of the method described above. The planetary gear transmission 11 also includes: a first gear 41 in the form of a planetary gear 42; a second gear 7 in the form of a ring gear 71; and a sun gear 9. The planetary gear transmission 11 also includes an acceleration sensor 6 disposed on the housing 3 of the planetary gear transmission 11.
[0047] The ring gear 71 is engaged with the planetary gear 42. Similarly, the planetary gear 42 is engaged with the sun gear 9.
[0048] Accelerometer 6 detects an acceleration signal that represents the acceleration of vibration on the housing 3 of the transmission device 1. In this case, the acceleration sensor 6 is arranged on the housing 3 such that the detected signal represents the vibration at the gear meshing 8 between the gear ring 71 and the planetary gear 42.
[0049] The device 2 can obtain the acceleration signal detected by the accelerometer 6, and according to... Figure 1 The method described herein is used to process the acceleration signal in order to determine the load on the bearing 5 of the planetary gear 42.
[0050] List of reference numerals
[0051] 1. Transmission device
[0052] 11 Planetary Gear Transmission
[0053] 2 equipment
[0054] 3 shells
[0055] 4 gears
[0056] 41 First Gear
[0057] 42 planetary gears
[0058] 5 bearings
[0059] 6 accelerometers
[0060] 7 Second gear
[0061] 71 gear ring
[0062] 8 gear meshing
[0063] 9 Sun Wheels
[0064] S1 determines the gear meshing frequency based on the acceleration signal.
[0065] S2 obtains the bearing load.
[0066] S11 filters the acceleration signal.
[0067] S12 decomposition and filtering of acceleration signal
[0068] S13 extracts the amplitude signal
[0069] S14 obtains the spectrum
[0070] S15 determines the gear meshing frequency based on the known spectrum.
[0071] S111 obtains the effective value signal
[0072] S112 filters the RMS signal.
[0073] S130 prepares signals by addition.
Claims
1. A method for determining the load on the bearing (5) of the gear (4) of a transmission device (1), the method comprising the following steps: The gear meshing frequency (S1) at the gear meshing (8) of the gear (4) in the transmission device (1) is obtained from the acceleration signal of the transmission device (1); and The load on the bearing is determined based on the known gear meshing frequency and reference value (S2).
2. The method of claim 1, wherein, The acceleration signal is the acceleration of vibration on the housing (3) of the transmission device (1).
3. The method according to any of the preceding claims, characterized in that, The gear meshing (8) is the meshing of the planetary gear (42) of the planetary gear transmission device (11) with the gear ring (71) of the planetary gear transmission device (11), and the bearing (5) is the bearing of the planetary gear (42).
4. The method according to any of the preceding claims, characterized in that, Determining the gear meshing frequency (S1) includes the following steps: The acceleration signal is filtered (S11); The filtered acceleration signal is decomposed into phase signal and amplitude signal (S12). The amplitude signal is extracted based on the decomposed acceleration signal (S13). The spectrum of the extracted amplitude signal is obtained (S14); and The gear meshing frequency is determined based on the known spectrum (S15).
5. The method of claim 4, wherein, Filtering the acceleration signal (S11) is to perform bandpass filtering on the acceleration signal; Among them, decomposing the filtered acceleration signal into phase signal and amplitude signal (S12) is to perform Hilbert transform on the filtered acceleration signal; Among them, extracting the amplitude signal based on the decomposed acceleration signal (S13) involves determining the absolute value of the decomposed acceleration signal; Specifically, obtaining the spectrum (S14) involves applying a Fast Fourier Transform based on the absolute value; and Specifically, the gear meshing frequency is determined based on the known spectrum (S15), which is based on the output of the fast Fourier transform.
6. The method according to any one of claims 4 or 5, characterized in that, Filtering the acceleration signal (S11) includes: obtaining the effective value signal of the acceleration signal (S111) and filtering the effective value signal (S112).
7. The method according to any one of claims 4 to 6, characterized in that, Before the step of extracting the amplitude signal (S13), a signal preparation step is performed by adding the filtered acceleration signal to the decomposed acceleration signal (S130).
8. An apparatus (2) configured to perform the steps of the method according to any one of claims 1 to 7.
9. A transmission device (1) having an apparatus (2) configured to perform the steps of the method according to any one of claims 1 to 7, wherein, The transmission device (1) includes a first gear (4) and a second gear (7), wherein the first gear (4) and the second gear (7) are in gear meshing (8), and wherein the transmission device (1) includes at least one bearing (5) of the first gear (4).