Measurements on the wind turbine transmission
Problems: Transmission error, transmission error, emissions of structure-borne noise and noise, mechanical wear on components.
Goal: Optimal design of wind power gearboxes, reduction of structure-borne noise emissions
Every gearbox and the individual parts installed in it are subject to manufacturing tolerances, which vary in tightness depending on the intended use and location of the entire assembly. Due to these manufacturing tolerances in combination with temperature and load-dependent component elasticities as well as assembly influences, the transmission function of the rotary motion and torque deviates from the ideal transmission function. This phenomenon is also known as transmission error (TE). The more complex a gear unit is, i.e. the more gear stages it has, including shafts, gears and bearings, the greater the sum of the individual transmission errors. The consequences of transmission errors are manifested by increased macroscopic and microscopic wear on the components and component surfaces. Furthermore, they are acoustically perceptible to humans through the emission of structure-borne sound and noise. Therefore, a measurement of the transmission error is necessary. This ensures that the error of each individual gear stage can be quantified.
Consequently, design-related influences, which differ greatly between spur or planetary gears, for example, as well as gear meshing errors can be analyzed using suitable measurement technology. Powerful software can be used to generate order and frequency spectra in two and three dimensions and to find correlations between transmission errors and structure-borne noise emissions. To collect measurement data, high-resolution incremental sensors are applied to the transmission input and output shafts. Depending on the shaft diameter, different sensor types are available for this purpose, such as one-piece hollow shaft encoders or a two-piece sensor system with a separate sensor head and a magnetic tape that spans the shaft. In parallel with the speed measurement, the structure-borne noise is measured by means of acceleration sensors at various points in the gear unit.
The recorded measured values are evaluated in the time and spectral domain.
Furthermore ROTEC ENGINEERING provides you with support and technical engineering know-how for problems related to vibration analysis of engines, transmissions and drive trains. With our know-how, we make a valuable contribution to your product in the areas of timing gear validation, valve train optimization, clutch design, transmission errors (TE), transmission optimization, oil supply optimization, powertrain measurement and optimization, current and voltage analysis, and the application of measurement technology.
Time domain analyses
- Dynamic torsion angle between transmission input shaft and output shaft
- Load-dependent gear stiffness
- Speed-independent vibration and structure-borne noise emissions
Spectral domain analyses
- Investigations of the tooth meshing by forming order or frequency spectra
- Display of 3D sequences by combining the spectra from several individual measurements, e.g. via load or rotational speed
- Formation of 2D sectional views over load or rotational speed for the selection of single orders or frequencies
- 2D representation to evaluate the correlation between transmission errors and structure-borne noise emissions