Dynamics
and Vibration
Analyses of
Gearbox in
Wind Turbine

Dynamics
and Vibration
Analyses of
Gearbox in
Wind Turbine

Dynamics
and Vibration
Analyses of
Gearbox in
Wind Turbine

Gearbox is the core part of a wind turbine which realizes the transmission and
energy transfer from wind blades to electric generator. The dynamics and vibration
properties of the gearbox especially of its geared rotor systems prominently
determine the efficiency and operating quality, even the whole-life expectation and
reliability of the machine set. In this book, the dynamic analyses and vibration
behaviors are investigated for the gearboxes which are popularly used to modern
wind turbines by using mechanics theories, finite element-based simulations,
experimental measurements, and vibration signal processing techniques.
Firstly, the background and main ideas of the book are described. Secondly, the
torsional dynamic model and vibration resonances are achieved based on the
lumped mass model of the geared rotor system, which is composed of two stages of
planetary gear trains and one parallel gear pair. Furthermore, the load sharing of the
planetary gear train based on the given torsion model is presented with considering
time-varying mesh stiffness, tooth backlash, fixing error, and manufacturing error
of the gears and carrier. Also, the measured strains at the gear tooth roots are used to
confirm that load-sharing analyses of the planetary gear train are acceptable. Based
on the model, the vibrations of both the geared rotor systems and the gearbox
housings are calculated under either the internal excitations coming from gear sets
or external loads transferring from wind loads.
Next, the parameter optimization for planetary gear system is defined and processed
based on the torsional dynamics of the geared rotor system of wind turbine.
The fault-induced vibrations of the geared rotor system are simulated, which
involves the popularly occurring fault of support misalignment of the rotor. The
rotor-misaligned fault-induced vibrations are of importance in practical manufacturing
error control and assembly processing optimization, even helpful in operating
condition monitoring and fault diagnosis.
And then, the whole gearbox finite element model (WG-FEM) is built, and its
natural frequencies and modes of the gearbox system (including shells and geared
rotors) are calculated. Experimental measurements of vibrations on the wind turbine
gearbox are performed on the test rig and on-site. The vibration signals of different
testing points are analyzed in time and frequency domains to explore the underlying complicated behaviors. Some technologies of Hilbert–Huang transform-based
analyses are also achieved in the vibration signal processing.
At last, the gear coupling frequencies and fault characteristic frequencies are
obtained from the vibrations of the gearbox housing.
In summary, the technologies and results of this work provide some good references
for dynamic design and vibration prediction and analysis for gearbox and
its geared rotor system of wind turbine, even for many other machines.
Keywords Gearbox in wind turbine
dynamics


Parameter optimization


Geared rotor system


Model of torsional


Load sharing of planetary gear train


Whole
gearbox finite element model
Vibration fault diagnosis


Whole gearbox modes


Vibration signal processing

ingkai Han
Jing Wei
Qingpeng Han
Hao Zhang