International Journal of Science and Research (IJSR)
ISSN (Online): 2319-7064
Index Copernicus Value (2013): 6.14 | Impact Factor (2013): 4.438
Modelling and Structural Analysis of Planetary
Geared Winch
Aditya Nigam1, Sandeep Jain2
1
M.Tech. Computer integrated manufacturing, Samrat Ashok Technological Institute, Vidisha 464001, India
2
Associate. Professor Department of Mechanical Engineering, Computer integrated manufacturing.
Samrat Ashok Technological Institute, Vidisha 464001, India
Abstract: Planetary gear sets are used widely in many diverse product applications. Their compact and co-axial design and gear ratio
make them preferable to counter-shaft gear drives. Planetary gear sets are complex, multi-mesh systems formed by multiple stages of
planet gears that are in mesh with a sun gear and a ring gear and they are held by a common carrier through needle bearings and
planet pins. Their design presents unique challenges stemming from a number of load factors issues, including their planet load sharing
behavior, dynamic response, deflections, and support conditions. This study investigates the influence of load factors on gear stresses,
and their impact on the resultant bending fatigue lives of the gears in planetary gear sets. These models are made by using part and
assembly design module in CATIA V5R20 software, while the analysis is done in ANSYS V14 software. Optimization is based on ANSYS
results, which can be used to enhance the efficiency of the design process.
Keywords: Planetary Gear Box Winch, Sun gear, Planet gear, Ring gear, Planet carrier.
1. Introduction
Planetary gearbox is widely used in industrial machineries
and machine tools to obtain speed reduction, which in turn
increases the torque. These gearboxes are used in many
applications such as power transmission system and hybrid
transmission systems. Planetary gear trains are one of the
main subdivisions of the simple planetary gear train
arrangement. The Planetary gear train arrangement in
general has a central “sun” gear which meshes with and is
surrounded by planet gears. The outer most gear, the ring Figure 1: Arrangement of Planetary gear train
gear, meshes with each of the planet gears. The planet gears
are held to a cage or carrier that fixes the planets in orbit 2. Methodology
relative to each other. Planetary gear is a widely used
industrial product in mid-level precision industry, such as Planetary gearbox is commonly used to obtain speed
printing lathe, automation assembly, semi-conductor reduction and increasing torque in winch mechanism. Winch
equipment and automation system. Planetary gearing could is a mechanical device powered by planetary gear reduction
increase torque and reduce load inertia while minimized the system for hauling or pulling. Planet carrier is basic but most
speed. important part of mechanical winch. It provides support to
the planet gear, bearings and the gear loadings. The strength
To compare with conventional gearbox, planetary gear box of the Planet carrier is an important parameter to be taken
has several advantages. One advantage is its unique into account while designing. In order to evaluate the
combination of both compact arrangement and outstanding strength, of the Planet carrier, a step by step approach is
power transmission efficiencies. A typical efficiency loss in adopted.
a planetary gearbox arrangement is only 3% per stage. This
type of efficiency ensures that a high proportion of the To solve this problem it is essential to carry out the analysis
energy being input is transmitted through the gearbox, rather of Planet carrier and redesign the existing Planet carrier in
than being wasted on mechanical losses inside the gearbox. order to improve strength as well as save material. Gears are
Another advantage of the planetary gearbox arrangement is present in all kinds of machinery and vehicles because of
load distribution. Because the load being transmitted is their advantages over other available methods of
shared between multiple planet gear, torque capability is transmitting power and matching the speeds and torques of
greatly increased. Higher load ability, as well as higher one machine to another. Gear transmissions usually exhibit
torque density is obtained with more planet gear in the high power-to-weight ratios, can be made very compact and
system. The planetary gearbox arrangement also creates present the major advantage of high efficiency.
greater stability due to the even distribution of mass and
increased rotational stiffness.
Volume 4 Issue 1, January 2015
www.ijsr.net
Paper ID: SUB15115 330
Licensed Under Creative Commons Attribution CC BY
International Journal of Science and Research (IJSR)
ISSN (Online): 2319-7064
Index Copernicus Value (2013): 6.14 | Impact Factor (2013): 4.438
• In future for optimization and design modification of gear-
train for better output performance.
• The most important advantages are decreased prototype
development and assessment time.
3. Finite Element Analysis
The finite element method is a technique for mathematically
modeling complicated shapes (feature) as an assembly of a
simpler shape (elements) that is more easily defined. Linear
Figure 2: Modeling of Planet carrier and non-linear problem in engineering field are of the great
importance to be studied in this work. Therefore, the Finite
Element package called Ansys V14 has been chosen to solve
this problem. The meshed carrier and planet gears are
examples of 3-D finite elements models (FEM). FEM here is
used to characterize the dynamics of the carrier and planet
gears efficiently and then these characteristics are split into
elements. These elements are connected with each other
through points called nodes. The complete collection of the
elements is called mesh. Restraints and loads are added after
this to the meshed part and whole thing then is called model.
One advantages of FEM is thus, many different design
Figure 3: Sun gear and Planet gear teeth meshing concepts can be tested via computer, and shape can often be
finalized before any prototype design. The finite element
technique has been used in this paper to study the modal
analysis of planet gears carries. The modal analysis has been
used to determine the natural frequencies and associated
mode shapes of the carrier system.
Figure 4: Planet gear and Ring gear
Figure 6: Meshed Wireframe view of planet carrier
Figure 5: Close view Planet gear and Ring gear teeth
meshing
These models are made using part modeling and assembly
design module generated in CATIA V5R20 software and
static analysis is done in ANSYS V14 software.
Optimization is based on ANSYS results, which can be used
to enhance the efficiency of the design process. Material
selection criteria is based factors such as strength, rigidity,
cost etc. FG260 is an appropriate element for planet carrier.
FG260 is cast iron material which is mainly used for casting.
Following are the objectives of the work:
• To carry out static analysis using ANSYS for analyzing Figure 7: Principal stress act on planet carrier
load effect on gears.
Volume 4 Issue 1, January 2015
www.ijsr.net
Paper ID: SUB15115 331
Licensed Under Creative Commons Attribution CC BY
International Journal of Science and Research (IJSR)
ISSN (Online): 2319-7064
Index Copernicus Value (2013): 6.14 | Impact Factor (2013): 4.438
4. Mathematical Modelling Pr = Present gear ratio
From equation 2, the ratio difference was found to be
The Planetary single stage, consists of a Housing, planet 106.85.
carrier with four planets, a sun and a planet-ring wheel. The Also, the rpm of sun gear can be found by the equation
planet-ring is non-rotating and can be considered as rigid Sun Gear RPM= I rpm……………………………...…… (3)
multi-body with discrete flexibilities of full gearbox with Where, I rpm = Input rpm
free boundaries. Technical parameters for the planetary Rd = Ratio difference
gearbox are tabulated in Table 1. The sun gear rpm was calculated to be 9.24 rpm from
equation 3.
The torque generated by the sun gear is given by
Torque in sun gear= P / ω…………………………… (4)
Where, P = Output power
ω= Angular velocity
Calculate torque generated by the sun gear was 22736.42
Nm
Figure 8: Meshed Wireframe view Sun and Planet gear
Figure 10: Meshed Wireframe view of Planet & Ring gear
Figure 9: Stress act on sun & planet
Table 1: Technical Specification of Gearbox
Parameters Sun Gear Planet Gear Ring Gear Figure 11: Stress act on Planet & Ring gear
Number of Teeth (N) 17 19 55
Pitch circle Diameter (DPC) 153 171 495
Root Diameter (DR) 135 153 517.5
Modular (m) 9 9 9
Pressure angle 20 20 20
From the data obtained from the technical specification of
gear box as shown in the Table 1, the rpm of the sun gear
can be found out by finding the gear ratio for the particular
or present stage (Pr) as given in equation 1.
Ratio (Pr) = Nr/Ns + 1 ………………...……… (1)
Where, Nr = Number of teeth in ring gear
Ns = Number of teeth in sun gear
From equation 1, the gear ratio of present stage was
calculated to be 4.23.
The difference in the gear ratio (Rd) is given by
Ratio Difference (Rd) = Fr/Pr……………….……… (2)
Figure 12: Close view Stress act on Planet & Ring gear
Where, Fr = Final gear ratio
Volume 4 Issue 1, January 2015
www.ijsr.net
Paper ID: SUB15115 332
Licensed Under Creative Commons Attribution CC BY
International Journal of Science and Research (IJSR)
ISSN (Online): 2319-7064
Index Copernicus Value (2013): 6.14 | Impact Factor (2013): 4.438
5. Result and Discussion [7] K.Mao, “gear tooth contact analysis and its application
in the reduction of fatigue wear”262(2007) 1281-1288
Study has been carried out to evaluate static analysis of the [8] Lin, Tengjiao, Ou, H, Li, Runfang, “A finite element
planetary gear-train using commercial software ANSYS method for 3D static and dynamic contact/impact
V14. Analysis is to find out the total amount of stresses of analysis of gear drives”- Computer Methods in Applied
any structural component by applied load. Initially, it was Mechanics and Engineering, Volume 196, issue 9- 12
carried out for the existing model of the planet carrier, sun & (February 1, 2007), p. 1716-1728
planet teeth meshing, planet & ring gear teeth meshing of [9] A. Kahraman, G.W. Blankenship, Steady state forced
planetary gearbox winch. In planet carrier, the maximum response of a mechanical oscillator with combined
principal stress at the region of shaft fixed was observed to parametric excitation and clearance type non-linearity,
be 3.6041e11Mpa as shown in (Figure no.-7). Sun gear teeth Journal of Sound and Vibration 185 (1994) 734–765.
and the planet gear teeth mesh together von-Mises Stress [10] User’s Manual, 2DPLANETARY, Planetary Gear Set
acting 8.2957e5Mpa. Shown in (Figure no.-9) and other Analysis Package, Advanced Numerical Solutions Inc.,
structural analysis shown in (Figure no.-11and12) Where 2002.
planet gear and ring gear perform good result under acting [11] Mr. Bharat Gupta, Mr. AbhishekChoubey, Mr. Gautam
von- Mises Stress of 8.4087e5Mpa.The size has been varied V. Varde, Contact stress analysis of spur gear,
by keeping loads and boundary conditions constant. The International Journal of Engineering Research &
results obtained using these relative conditions. Technology (IJERT) Vol. 1 Issue 4, June - 2012 ISSN:
2278-0181.
6. Conclusion [12] SunyoungPark ,Jongmin Lee, Uijun Moon, Deugjo
Kim, „Failure analysis of a planetary gear carrier of
The results obtained from the finite element analysis, the 1200HP transmission‟, Engineering Failure Analysis 17
Planet carrier of gearbox is manufactured by cast iron (2010) 521–529.
FG260 material. the model showed good results with [13] M. Rameshkumar, P. Sivakumar, S. Sundaresh and K.
maximum principal stress of 3.6041e11Mpa and with factor Gopinath, „Load Sharing Analysis of High-Contact-
of safety is good as compared to other modified models. Ratio Spur Gears in Military Tracked Vehicle
These results are so far better than existing model. In Applications‟, gear technology, july 2010, pp.43-50
practice analysis is also important factor for the optimum
design and reverse engineering of any mechanical structure References
and system.
Aditya Nigam received the bachelor's degree in 2010
7. Scope For Further Work in Mechanical Engineering from RGTU University
Bhopal. He is currently pursuing Master’s degree in
Computer integrated manufacturing from Samrat
This process helps in finding the optimized design for
Ashok Technological Institute, Vidisha.
planetary gear trains in which it has the best performance
without any failure and with optimum loads acting on the Mr. Sandeep Jain Associate Professor, Department
planet carrier. The main aim of this research is to optimize of Mechanical Engineering. Computer integrated
the planetary gear train through load analysis, to prevent manufacturing. Samrat Ashok Technological Institute,
load failure from happening in the future. Vidisha 464001, India.
References
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Paper ID: SUB15115 333
Licensed Under Creative Commons Attribution CC BY
