Investigation Report: Transient Load Impact on Gearbox Reliability

This report investigates the impact of transient loads on gearbox systems, particularly in wind turbines, where these loads contribute to frequent failures and increased maintenance costs. The report highlights the mechanisms of transient loads, including torque reversals and emergency stops, and id...Read More

Investigation of Transient
Load in Gearbox

Introduction
 Power is a form of energy which is useful in driving the entire
load over a machine or machinery components.
 Antoniadou and et. al., (2015) stated that power trains in wind
turbines have an expected service life of about 20 years.
 According to Zhao and et. al., (2014), E-stops or emergency stops
are considered as the most frequent process which affects the
functioning of gearbox in transmission systems.

Mechanism of transient loads in gearbox
 Transmission systems are of
different types.
 These include automatic,
semi-automatic and
continuously variable
transmissions.

Main Problems
 Despite of huge life span, the gearbox gets affected by
transient loads. This is a big issue which needs to be resolved.
 The overall cost of maintenance increases for windturbines
which is definitely affecting the functioning of these devices.
 Components or factors which are contributing to the
deteriorations in functioning of gearbox need to be evaluated.

Wind turbine drivetrain

Continued...
 Gearbox models fail due to consistent experience of variable
loads.
 The structure of gearbox is kep aloof from the main body of
turbine because of this transient load variability.
 Drivetrain cannot rotate steadily because of changing torque
and consequent damage to the device.

Factors leading to failure
 The amount of load and weight over device drivetrain is
quite high as compared to the design specifications.
 Lack of knowledge and research over wind shear forces has
also led to deficiencies in the structural design of system.
 Overloading due to higher power expectations has caused
severe problems in the complete design.

Formulae for shear forces

Importance of transient loads
 The transient loads are also known as torque reversal loads.
 These are importance because gearbox function with help of
these loads.
 Energy transfer from one device to another takes place due
to this load and its principle aspects.
 Emergency stops and improper construction leads to device
failure.

Continued...

References
Books and Journals
 Antoniadou, I. and et. al. (2015). A time–frequency analysis
approach for condition monitoring of a wind turbine gearbox
under varying load conditions. Mechanical Systems and Signal
Processing. 64. pp.188-216.
 Walker, P. D. and Zhang, N., (2013). Modelling of dual clutch
transmission equipped powertrains for shift transient simulations.
Mechanism and Machine Theory. 60. pp.47-59.
 Zhao, C. and et. al., 2014. Design and stability of load-side
primary frequency control in power systems. IEEE Transactions
on Automatic Control. 59(5). pp.1177-1189.