Design and analysis of planetary gear train

1. Presentation on
Design and Analysis of a
Planetary Gear Train
by
● Pushkar Raj (BTECH/19030490062)
● Raghuraj singh (BTECH/19030490064)
● Swapnil Dwivedi
(BTECH/19030490104)
Department of Mechanical Engineering
Birsa Institute of Technology Sindri ,
Dhanbad Under the guidance of Prof. N.P. Choudhary, Assistant
Professor, Department of Mechanical Engineering

2. 1. Introduction
Gear System:
A gear system is a device that transfers rotatory motion precisely from one location to another. A gear
is an arrangement of teeth all the way around its rim. The teeth operate as machine components,
transmitting rotational motion to the wheel by engaging the teeth of the other rotating gear in a
sequential manner.
Planetary Gear Train:
An epicyclic gear train (also known as a planetary gearset) is made up of two gears with the centre of
one rotating around the centre of the other. A carrier connects the two gears' centres and turns the
planet and sun gears' pitch circles so that they roll without slipping. An epicycloid curve is traced by
a point on the planet gear's pitch circle.
F

3. 2. Abstract
Gears in the Epicyclic gear trains are one of the most critical components in the
mechanical power transmission system in which failure of one gear will affect the
whole transmission system, thus it is very necessary to determine the causes of
failure in an attempt to reduce them. The different modes of failure of gears and
their possible remedies to avoid the failure are bending failure (load failure),
Pitting (contact stresses), scoring and abrasive wear, in any case it is related to the
loads acting on the gear and this research deals with the Optimization of the gear
design leading to the reduction in the load failure of the gears.This study carried
out in this research shows the optimization analysis of the epicyclic gear train to
reduce load failure.

4. 3. Literature Review
Case Study: Planetary Gear
Planetary gear sets, also known as epicyclic gear sets, are commonly used in many automotive,
aerospace, industrial and wind turbine gearbox applications. As they employ N number of identical
planet branches, they allow the power transmitted to be split into N parallel paths to achieve maximum
power density (power to weight ratio). It consists of a planetary gear set with one planet gear (pinions),
a sun gear, a ring (internal) gear and a planet carrier (a relatively rigid structure that supports the
planets). They are also typically quieter than their fixed-centre, lay-shaft counterparts as the self-
centering capability of central members (sun gear, ring gear and the carrier) not only allow wider
manufacturing tolerances for the gears and the carrier, but also result in reduced noise and vibration
levels. In addition, different input-to-output speed (torque) ratios can be achieved with the same
planetary gear set by simply changing the input, output and reaction (fixed) members. This feature
makes them especially desirable for several applications such as automotive automatic
transmissions.With these proven advantages in place, planetary gear sets are also known to exhibit
several unique behaviours, which cannot be found in other fixed-centre gear trains. Some of these
behaviours such as planet load sharing as a function of manufacturing errors and planet mesh phasing
for cancellation or neutralisation of the gear mesh excitations have been studied extensively.

5. Title of paper/textbook Description
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Design, LoadAnalysis and Optimization of
Compound Epicyclic Gear Trains
Syed Ibrahim Dilawer, Md.Abdul Raheem
Junaidi, Dr.S.Nawazish Mehdi
American Journal of Engineering Research
(AJER) 2013
Load sharing analysis and reliability
prediction for planetary gear train of
helicopter
Ming Li, Liyang Xie, Lijun Ding
Research paper - Mechanism and Machine
Theory 115 (2017) 97–113
Simulating the dynamic behavior of planetary
gearbox based on improved Hanning function
Oussama Graja, Bacem Zghal, Kajetan
Dziedziech,Fakher Chaari,Adam Jablonski,
Tomasz Barszcz, Mohamed Haddar
Comptes Rendus Mecanique
C. R. Mecanique 347 (2019) 49–61
The purpose of this research paper is to determine the optimal
design of the gear train with the load analysis carried out in
the gear trains by varying the module (3, 4, 5, 6) for all the
gears for three different power levels 10 HP, 15 HP and 20HP.
The Wear tooth load (Ww) for all the gears in the gear train is
higher than the Dynamic tooth load (Wd), and the Dynamic
Tooth load (Wd) is less than Static tooth load (Ws).
In this paper, a method for predicting the reliability of
planetary gear train in partial load state is presented. Unequal
load sharing of the planetary gear train is very common, so its
impact on reliability of the gear system cannot be ignored.
The results of the reliability model have shown that unequal
load sharing among planet gears reduces the reliability of
planetary gear train.
In this paper, an improved Hanning function is proposed to
take into account the variable vibration transmission path in
planetary gears. A dynamic model is used to build all
vibration sources including sun, planets, and ring gear. A
modulation function is proposed as a time-varying distance
between the position of the planets and the location of the
transducer.

6. S
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ner/textbook
4. An Analysis of the Gear Meshing
Characteristics of the Main Planetary Gear
Trains of Helicopters Undergoing Shafting
Position Changes
Li Xuejun, Jiang Lingli, Hua Dengrong, Yin
Daoxuan, and Yang Dalian
International Journal ofAerospace
Engineering
Volume 2021,Article ID 9965818 (2021)
In this research investigation, the gear meshing
characteristics of the main transmission planetary gear
train of helicopters when the position of the planetary
carrier (for example, the main rotor shaft) changed were
examined. The revealed dynamic response characteristics
of the helicopter shaft systems under changes in the
relative position could provide a theoretical basis for the
failure mechanism analysis and the operational status
monitoring of the helicopter transmission.
5. TVMS calculation and dynamic analysis of
carburized spur gear pair
Vikash Kumar, Anurag Kumar, Sanjeev
Kumar, Somnath Sarangi
Mechanical Systems and Signal Processing
166 (2022) 108436
The present model proposes an analytical aspect for
estimating the TVMS of a carburized spur gear pair
having tooth cracks at the root. The obtained results show
that the carburized spur gear pair has more stiffness in
comparison to uncarburized one under similar operating
conditions keeping similar parameters and crack depth.
processing. The results obtained through these techniques
successfully depict the severity of crack present on the
carburized spur gear pair and have less impact as
compared to uncarburized one

7. 4. Objective
Use Dynamic System Modelling and perform dimensional
modification in gear usingANSYS Software.
Fig. 1: Drive Train Model

8. 5. Modelling and Methodology
The Compound Epicyclic Gear train is taken from BHEL and the
parameters are altered for the optimization purposes. The Gears,
arms, keys and annulus are designed in Catia V5 which is shown in
Figure. This model of the epicyclic gear train failed due to the high
loads acting on the gears. As we know that the gear is one of the most
critical components of the power transmission system, failure in the
gear will affect the whole transmission system and thus it is necessary
to optimize the gear for low load operation and its effective delivery
of power transmission. Loads in an epicyclic gear train are divided
into four parts: Tangential Tooth Load (Wt), Static Tooth Load (Ws),
Dynamic Tooth Load (Wd) and Wear Tooth Load (Ww).
Fig. 2: CAD Model of Planetary Gear

9. 6. Software used

10. 12. References
1 Dilawer S. I., Junaidi M. A. R., and Mehdi S.N. (2013) Design, Load Analysis and Optimization of Compound Epicyclic
Gear Trains, American Journal of Engineering Research (AJER), 2013.
2 Li M., Xie L., and Ding L. (2017) Load sharing analysis and reliability prediction for planetary gear train of helicopter,
Research paper - Mechanism and Machine Theory 115 97–113.
3 Graja O., Zghal B., Dziedziech K., Chaari F., Jablonski A., Barszcz T., and Haddar M. (2019) Simulating the dynamic
behavior of planetary gearbox based on improved Hanning function, Comptes Rendus Mecanique C. R. Mecanique 347
(2019) 49–61.
4 Xuejun L., Lingli J., Dengrong H., DaoxuanY
., and Dalia Y
. (2021) An Analysis of the Gear Meshing Characteristics of
the Main Planetary Gear Trains of Helicopters Undergoing Shafting Position Changes, International Journal of
Aerospace Engineering Volume 2021,Article ID 9965818.
5 Kumar V., Kumar A., Kumar S., and Sarangi S. (2022) TVMS calculation and dynamic analysis of carburized spur gear
pair, Mechanical Systems and Signal Processing 166 (2022) 108436.

11. Thank You!