How to Measure the Vibration of H Series High-Power Gearboxes
1、 Preparation before measurement
Basic information confirmation: Sort out the core parameters of the gearbox, such as rated power, shaft speed at all levels, number of gear teeth, and bearing model, and calculate the theoretical values of shaft rotation frequency, gear meshing frequency, bearing characteristic frequency, etc. in advance to serve as a benchmark reference for subsequent spectrum analysis.
Instrument selection and calibration: Select piezoelectric acceleration sensors, vibration signal analyzers, and supporting data acquisition systems to ensure that the instrument accuracy meets standard requirements and is within the validity period of metrological calibration.
Pre treatment of working conditions and measuring points: Adjust the gearbox to a stable operating state at rated speed and load, clean the oil and rust on the surface of the bearing seat and other measuring points, and ensure that the sensor is in rigid contact with the measured surface.
2、 Standard layout of measuring points
Core measuring point location: All measuring points should be prioritized to be arranged on the rigid surfaces of the bearing seats and housing corresponding to each axis, avoiding weak positions such as housing cover plates and welds that are prone to local resonance.
Three directional full coverage: Each measuring point must simultaneously collect vibration data in the horizontal, vertical, and axial directions, fully covering the radial and axial vibration components to avoid missing fault features such as misalignment and looseness.
Sensor fixing requirements: Priority should be given to using magnetic seats or bolts to rigidly fix the sensor. It is forbidden to place it directly on the surface of the box to prevent high-frequency signal attenuation and ensure stable signal transmission without interference.
3、 Standardized data collection
Core measurement parameters: The effective value of vibration velocity (mm/s) is used as the main evaluation index, and the peak value of vibration acceleration (m/s ²) is synchronously collected to capture high-frequency impact signals. If necessary, the peak value of shaft vibration displacement (μ m) is supplemented to evaluate low-frequency large vibrations.
Sampling parameter setting: The sampling frequency is set to 2.56~3 times the highest analysis frequency of the target, and the single channel single acquisition time is not less than 10 seconds to ensure the representativeness and spectral resolution of the signal.
Multi condition data retention: Complete recording of full condition data under no-load, 50% load, and 100% rated load, while synchronously recording auxiliary information such as operating oil temperature and ambient temperature for subsequent data comparison and analysis.
4、 Data analysis and compliance evaluation
Basic indicator verification: First, check whether the effective value of vibration velocity meets the A/B/C/D four level evaluation area specified in GB/T 41850.9-2024, and determine whether the overall vibration intensity is within the qualified range.
Deep spectrum analysis: Generate a spectrum map through fast Fourier transform to identify components such as meshing frequency and its sidebands, bearing fault characteristic frequencies, etc. Combining phase analysis to distinguish different types of faults such as imbalance, misalignment, tooth wear, and bearing pitting.
Trend comparison judgment: Compare the current measurement data horizontally and vertically with the historical benchmark values of the equipment and the normal operation data of the same model gearbox to avoid the randomness of a single measurement and accurately identify early degradation trends.
