A Review paper on Dual Mass Flywheel system

International Journal of Science, Engineering and Technology Research (IJSETR), Volume 5, Issue 1, January 2016
A Review paper on Dual Mass Flywheel system
Prof. R.S. Shelke, D. G. Dighole
Department of Mechanical Engineering
Sir Visvesvaraya Institute of Technology, Nashik, Maharashtra, India.
Savitribai Phule Pune University
Mo. No. 9921146501

ABSTRACT
During the power stroke vibrations are occurred due to the
slight twist in the crankshaft. The combustion cycles of a
4-stroke engine produce torque fluctuations which excite
torsional vibration to be passed down the drive train. Hence it
is necessary that the vibrations generated by engine be reduced
or isolate, so that the operator / driver was feel lesser fatigue.
Dual mass flywheel is a multi-clutch device which is used to
dampen. The torsional frequency is defined as the rate at which
the torsional vibration occurs. When the torsional frequency of
the crankshaft is equal to the transaxles torsional frequency an
effect known as the torsional resonance occurs. When the
operating speed of the engine is low, vibration occurs due to the
torsional resonance and this can be avoided using dual mass
flywheel. The resulting noise and vibration, such as gear rattle,
body boom and load change vibration, result in poor noise
behavior and driving comfort. The objective while developing
this concept was to isolate the drive train from the torsional
vibrations. This paper includes the development of inertia
augmentation mechanism and development of optimized
flywheel using this mechanism. The dual mass flywheel
comprises primary flywheel and secondary flywheel and two
springs.
Keywords: Dual Mass Flywheel, Arc Spring, Torsional
Resonance and Torsional Frequency.
simple model designed to simulate fundamental vibration
behavior. The engine, transmission and vehicle are
represented as rotating inertias connected by springs. The
spring C3 represents the stiffness of the drive train, while
spring C2, located between engine and transmission, and
represents the spring characteristic of the torsion damper.
Such a system has two vibrations modes. The first mode, with
a natural frequency of between 2 and 10 Hz, is known as the
tip-in/back-out reaction. This is generally excited by a
driver-induced load change. The second mode, where the
transmission inertia vibrates against engine and vehicle, has
a natural frequency of 40 - 80 Hz with conventional torsion
dampers. This is a typical cause of a gear rattle.
Consequently, the tuning of a conventional
automotive torsion damper – a clutch disc with its
corresponding spring characteristic - always involves
compromise. The upper graph of Fig. 2 shows typical speed
fluctuations in a vehicle with a clutch disc. In this case, the
friction-damped resonance is located at around 1700 rpm.
Further damping of this resonance leads to a worsening of
the hypercritical isolation of rotational vibrations (at speeds
higher than the resonance). [2]
I. INTRODUCTION
The clutch system in a vehicle performs two main
functions:
• Power interruption and modulation during start up and
when shifting
• Reduction of rotational vibrations in the drive train induced
by engine irregularities
Rotational vibrations affect durability of the drive train
components and create
• Gear rattle
• Body boom
• Tip-in/back-out vibrations
These factors produce considerable noise and a loss in
driving comfort. The main cause of these rotational
vibrations is variation in torque. This variation results from
the discrete piston combustion cycle of the engine as a
function of the ignition frequency. These factors produce
considerable noise and a loss in driving comfort. The main
cause of these rotational vibrations is variation in torque.
This variation results from the discrete piston combustion
cycle of the engine as a function of the ignition frequency.
The vehicle drive train is a vibrating system. Fig. 1 shows a
Fig. 1 Vehicle drive train with vibration modes [1]
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ISSN: 2278 – 7798
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International Journal of Science, Engineering and Technology Research (IJSETR), Volume 5, Issue 1, January 2016
The goal of torsion damper development is to keep the
torsional vibrations induced by the engine as far as possible
from the rest of the drive train. A conventional system only
satisfies this requirement at high engine speeds, because the
attainable torsion damper spring rates lead to natural
frequencies which are always within the normal driving
range.
Fig. 2 Torsional vibration isolation with conventional clutch disc and dual mass
flywheel [2]
This unsatisfactory situation led to the development
of a new torsion damper concept - the dual mass flywheel
(DMF). This design shifts part of the flywheel inertia to the
transmission input shaft and drastically lowers the torsion
damper spring rate by introducing new spring designs (Fig.
3), thus reducing the resonance speed to very low engine
speeds. Fig. 2, lower graph, shows the hypercritical isolation
of rotational engine vibrations (starting from idle speed).
Improvements in driving comfort achieved by the
dual mass flywheel, together with low-cost designs resulting
from goal-oriented, value-analyzed development, has led to
the increased popularity of this system. Currently the LuK
dual mass flywheel is used by ten car manufacturers in
approximately 80 different models. [2]
Fig. 3 Principle of the dual mass flywheel [2]
concerning light flywheels. The first is that they do not
contribute to power output. The second is that they do. Which
thought is correct? In fact both, in a way, are correct. If we
measured the power output of an engine first with light
flywheel and then again with the standard part on an engine
dyno, no change in power will be seen to occur. At first it
appears that the light flywheel has done nothing and was a
total waste of cash. This is not the case. A dyno that shows
max power at constant revs does not demonstrate what
happens to an engine's power output in real life situations like acceleration. If an engine is accelerated on a dyno (we
are talking about a rate of around 2000 rpm a second) it
would show a power output of around 20%-25% less than at
the constant rev state.
The reason for this is that when accelerating a
vehicle the engine not only has to push the total mass of the
car but the internal components of the engine need to be
accelerated also. This tends to absorb more power as the extra
power is used accelerating the internal mass of the engine
components and is why a motor accelerating on a dyno will
produce less power than at constant revs. Also it must be
remembered that the rate of acceleration on the engine
internals is much greater that the rest of the car. This would
then suggest that by lightening the flywheel, less power
would be required to accelerate it and therefore more power
would be available to push the car along. Obviously, there’s a
certain minimum amount of flywheel inertial that should be
resent for several reasons:
1. Idle stability
2. Tolerance of high compression, cam overlap, etc
3. Better clutch operation for low speed and traffic
operation
4. Fewer load reversals on the driveline during low speed
5. Better traction
6. The carburetor’s accelerator pump and off-idle circuit
settings are closer to “real
world”
7. Damps vibration out some
8. Oil pressure is more consistent
Lighter flywheel offers the following advantages
1. Improves acceleration
2. Improves braking
3. Better suspension compliance in non-IRS where
flywheel gyro wraps up the springs under brakes
4. Reduced overall weight
On the other hand lighter flywheel leads to following
problems;
1. Is harder to kick through
2. Requires slightly higher idle speed screw setting for
stable idle
3. Is more likely to stall when cold/out of tune
4. Is easier to shift
5. Has better braking (unless you disconnect the motor by
pulling the clutch in while braking)
6. Requires more delicate touch with the clutch in traffic
7. Harder on the primary chain
8. Less tolerant of “walking speed” in gear
The main function of engine flywheel is to reduced
fluctuations in power and produced smooth transmission of
power to wheels. There are two schools of thought
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ISSN: 2278 – 7798
All Rights Reserved © 2016 IJSETR
International Journal of Science, Engineering and Technology Research (IJSETR), Volume 5, Issue 1, January 2016
A. Problem statement
In an ordinary conventional flywheel the engines
ignition-induced rotational speed irregularity causes
torsional vibration in the vehicles driveline also the
fluctuations in engines speed. At a given speed the ignition
frequency is equal to the natural frequency of the driveline so
that extremely high vibrations amplitudes occur that causes
rattle in transmission. Also more mass of flywheel increases
the cost of engine.
Fig.5. Dual Mass Flywheel System
.
B. Proposed methodology
The arrangement of the dual mass flywheel is best explained
by the mathematical model below. The model is a two spring
two
mass
model
graphically
represented
as
below
Fig.6.Dual Mass Flywheel System
Fig. 4 Graphical Model of spring mass flywheel system
The fig. 4 shows free un-damped vibrations set up of two
mass- two spring system. As shown in the figure the input to
the system is in the form of an low energy intermittent input
from any power source (excitation) , this results in free
undamped vibrations are set up in the system resulting in the
free to and fro motion of the mass (m1)& (m2) , this motion
is assisted by gravity and will continue until resonance
occurs, i.e., the systems will continue to work long after the
input (which is intermittent) has ceased. Hence the term free
energy is used.
From Fig .5 it is clear that in addition to the mass of the
flywheel , the couple owing to the centrifugal and centripetal
forces keeps the flywheel into motion for longer time thereby
increasing the work done by the system hence the
output from the given system increases.
Dual mass flywheel is represented in figure below:
The dual mass flywheel system is as shown above. The
flywheel comprises of the flywheel hub which is keyed to the
engine shaft,. Hub carries the flywheel body, on which the
flywheel gear ring is mounted. The flywheel body is recessed
at the rim inner side to receive the spring. Two springs and
two masses are used hence the flywheel has dual masses from
which the name of the flywheel originates. As the engine
power is delivered to the flywheel, the jerk applied will set
the flywheel into motion, so also the jerk is applied to the
masses, and as explained in the two spring two mass system
the two masses oscillate to generate the free energy as
explained earlier. The motion of the masses gives extra
impetus to the flywheel body due to which we get extra
revolutions from the same jerk as applied to the conventional
flywheel. Thus it is able to achieve more inertia
II. LITERATURE REVIEW
There has been a great deal of research on gear analysis,
and a large body of literature on energy storage system has
been published. The origins and use of flywheel technology
for mechanical energy storage began several hundred years
ago and developed throughout the Industrial Revolution. One
of the first modern dissertations on the theoretical stress
limitations of rotational disks is the work by Dr. A. Stodola
whose first translation to English was made in 1917.
Development of advanced flywheel begins in the 1970s.
Rotating wheels have been used to store and deliver energy
since prehistoric times. The potter’s wheel is perhaps the first
invention to resemble a flywheel and it has existed for 4,000
years. The first instance of the word flywheel occurred in
1784 during the industrial revolution. At this time flywheels
were used on steam engine boats and trains and were often
used as energy accumulators in factories. Flywheels became
more popular with steep drops in the cost of cast iron and cast
steel. In the industrial revolution, flywheels were very large
and heavy so that they could store significant energy at low
rotational speeds. The first use of flywheels in road vehicles
was in the gyrobuses in Switzerland during the 1950’s. The
flywheels used on the buses were 1500kg and had a diameter
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ISSN: 2278 – 7798
All Rights Reserved © 2016 IJSETR
International Journal of Science, Engineering and Technology Research (IJSETR), Volume 5, Issue 1, January 2016
of 1.626 meters. When they were fully charged they could
store 3.3×107 Joules. Flywheels are now found in many road
vehicles as well as space, sea and air vehicles. Flywheels are
also used for energy storage in power plants and as voltage
controllers. Newly raised concerns about the environment
have increased interest in flywheels.
Kevin Ludlum [3] studied a flywheel is an energy storage
device that uses its significant moment of inertia to store
energy by rotating. Flywheels have long been used to
generate or maintain power and are most identified with the
industrial age and the steam engine. In one sense it can be
thought of as a rechargeable battery that store energy in the
form of mechanical energy instead of electrochemical.
Flywheels have been gaining popularity as a possible
replacement for chemical batteries in vehicles, but until last
year there was no record of a flywheels being used to increase
the efficiency of a bicycle.
S H Salter [4] discussed here that it is easy to make a device
that will respond vigorously to the action of sea waves.
Indeed, it is quite hard to make one that will not. However,
the conversion of the slow, random, reversing energy flows
with very high extreme values into phase-locked
synchronous electricity with power quality acceptable to a
utility network is very much harder. This paper describes a
range of different control strategies of varying degrees of
sophistication and then describes possible conversion
equipment for high-pressure oil and water and low-pressure
air. Like many renewable energy sources, waves would
benefit from some form of energy storage, particularly if they
are to be used in weak island networks. Flywheels, gas
accumulators, submerged oil/vacuum accumulators, thermal
stores and reversible fuel cells are discussed, with emphasis
on the coupling hardware. This leads on to a description of a
new type of hydraulic machine with digital control which has
been specially designed for high efficiency and flexible
control of multiple erratic sources.
Dr. Robert Hebner, et.al. [5] In the past year, the researchers
at the Center for Electro mechanics at The University of
Texas at Austin (UT-CEM) and the Nanotech Institute at The
University of Texas at Dallas (UTD) began research efforts
on improved flywheel designs and flywheel materials to meet
energy storage requirements for the grid. UT-CEM’s initial
effort focused on determining the power and energy
requirements for a flywheel energy storage system at various
points on the grid. UT-CEM researchers used real-world data
from a newly developed community in Austin, TX to analyze
the effect of energy storage at the home level, transformer
level, and the community distribution level. With
requirements defined, an optimization code was developed
for sizing a flywheel energy storage system for the grid.
Results of this optimization are shown for today’s flywheel
using conventional materials.
Rudolf Glassner, Kottes [6] A dual mass flywheel for a
drive train of motor vehicle includes a primary flywheel
mass, a secondary flywheel mass & coupling device. The
coupling device includes at least two pivot levers associated
with secondary flywheel mass that interact with the
controlleled profile formed on the primary mass. The pivot
levers are pretension against the controlled profile in radial
direction by an elastic element. A control segment of elastic
element is disposed radially inside the control profile.
Park, Dong-Hoon Suwan- Si, Kyunggi- Do [7] A dual mass
flywheel for a vehicles includes a primary flywheel connected
to a crankshaft of an engine, a damper housing integrally
formed in a circumferential direction of primary flywheel a
secondary flywheel is connected to input shaft of a
transmission and rotatably mounted on hub of primary
flywheel; driven fingers integrally formed on a second
flywheel and inserted vertically into the damper housing to
be forced by a damper spring. The damper spring comprises
two springs sets symmetrically disposed within the damper
housing, one end of each damper springs being driven by the
stoppers which are integrally formed on primary flywheel,
while the other end of the spring sets drive the driven fingers
of the secondary flywheel. The primary & secondary flywheel
is integrally provided with projections for preventing the
damper spring from being excessively compressed &
damaged. The damper spring comprises a plurality of
springs, each having different spring coefficients and the
damper spring is supported by a plurality of sliding guides or
blocks.
Research Gap
From the above discussed literatures, it is concluded that
most of the work had been done on study the performance of
flywheel, dual mass flywheel act as vibration isolators in
engine, energy storage of flywheel etc. Nowadays the
requirement of energy storage of flywheel is more in small
size, because of the space constraint in engines. This paper
describes the improvement of energy storage capability by
using dual mass flywheel with same size as compared to
conventional flywheel.
III. WORKING STEPS
Typical working steps involved in the proposed work are
mentioned as below
Step 1: Literature Review
In this phase literature survey of dual mass flywheel systems,
the importance of DMF studied as compared to conventional
flywheel. By referring journal like journal, International
papers, European patents ,US patents etc.
Step 2: System design & Mechanical design of the DMF for
engine of following specifications
Prime mover selection
Make: Crompton Greave Model: IK-35
Engine is Two stroke Spark ignition engine with following
specifications:
Bore diameter: 35 mm
Stroke: 35 mm
Capacity: 34 cc
Power out pu : 1.2 BHP at 5500 rpm
Torque: 1.36 N-m @ 5000 rpm
Dry weight: 4.3 kg
Ignition: Magneto ignition
Direction of rotation: Clockwise .looking from driving end
Carburetor: ‟B‟ type
Cooling: Air Cooled engine
Step 3: Mathematical model development of system for dual
mass flywheel system.
Step 4: Selection of materials of flywheel shaft, flywheel,
flywheel mass , arc spring , dyno brake pulleyetc.
Step 5: System design for mechanical component like the
coupling for engine connection, flywheel base, flywheel
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International Journal of Science, Engineering and Technology Research (IJSETR), Volume 5, Issue 1, January 2016
shaft, arc springs, flywheel mass, dyno brake pulley, chassis
connection for given system of operation. This phase
includes the planning of system as per the sketch above .
Step 6: Mechanical design of all components of the set up
using theoretical formulae .for mechanical component
engine
Step 7: Mechanical design validation using ANSYS for
critical components of the system will be designed and
validated .
Step 8: Validation of strength calculations of critical
components viz, engine connection , engine shaft , mass
lever, mass , dyno brake pulley , flywheel base, chassis
connection using ANSYS
Step 9: Results and Discussion based on experimentation.
Testing of the developed system with and with Dual mass
system & Conventional system by removing spring &
masses.
FUEL TANK
BEARING 6005
ENGINE
FLYWHEEL DISK
MASS HINGE PIN
MASS LEVER
MASS
ROPE
DYNO-BRAKE PULLEY
FLYWHEEL SHAFT
FLYWHEEL HUB
LOAD
COUPLING SHAFT
BEARING HOUSING
BASE FRAME
SCHEMATIC OF DUAL MASS FLYWHEEL TEST RIG
Fig. 8 Schematic of dual mass flywheel test rig
IV. EXPERIMENTAL SETUP OF DUAL MASS FLYWHEEL
The experimental test rig consist of two stroke petrol
engine is paired with the planetary dual mass flywheel
mounted on flywheel shaft, by love joy coupling. The
flywheel shaft is mounted on base plate with the help of deep
groove ball bearing. The torsional vibration damper is
incorporated into the flywheel as a two arc spring and two
masses on the conventional flywheel. For this purpose the
flywheel is divided into a primary and a secondary mass
hence the name exists “dual mass flywheel”. The
unidirectional ball bearing called as unidirectional clutch is
mounted on flywheel shaft with bearing mounting to avoid
opposite side rotation of dyno brake pulley. The dyno brake
pulley is paired with unidirectional clutch. The rope is
rapped on dyno brake pulley with one end is tie on base plate,
and another end is tie on weighing pan.
FUEL TANK
BEARING 6005
ENGINE
MULTI-RIM FLYWHEEL
ROPE
DYNO-BRAKE PULLEY
FLYWHEEL SHAFT
FLYWHEEL HUB
LOAD
COUPLING SHAFT
Fig. 9 Actual setup of dual mass flywheel test rig
BEARING HOUSING
BASE FRAME
SCHEMATIC OF FLYWHEEL TEST RIG
Fig. 7 Schematic of conventional flywheel test rig
V. PROCEDURE
1) Start engine by turning
2) Let mechanism run & stabilize at certain speed (say 1300
rpm)
3) Place the pulley cord on dynamo brake pulley and add 500
gm weight into, the pan, note down the output speed for this
load by means of tachometer.
4) Add another 500 gm cut & note down the output speed for
this load by means of tachometer.
5) Take data of speed up to adding 5 kg weight.
6) Repeat above process with removing weight.
7) Tabulate the readings in the observation table for
conventional and dual mass flywheel system.
8) Plot torque Vs speed, Efficiency Vs speed &
Power Vs speed characteristics.
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ISSN: 2278 – 7798
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International Journal of Science, Engineering and Technology Research (IJSETR), Volume 5, Issue 1, January 2016
VI. EXPECTED OUTCOME OF THE PROJECT The expected outcome of the system with dual mass flywheel
system & without dual mass flywheel system (conventional
system) is effectiveness of dual mass flywheel system with
respect to conventional system. Also the improvement in
power output as well as efficiency with using dual mass
flywheel geometry.
VII. OBJECTIVE AND SCOPE
A. Objectives of project
1. Development of mathematical model for optimization
of flywheel mass to derive stipulated output power.
2. Design and development of inertia augmentation
mechanism.
3. Design and development of optimized flywheel using
inertia augmentation technique.
4. Test and trial on optimized flywheel using test rig.
5. Plot performance characteristic curves.
B. Scope
1. Lowered weight of flywheel system will reduce system
weight thereby leading to better fuel economy of vehicle
and also reduce overall material cost.
2. Compact size: The size of the flywheel will lead to better
cabin space of vehicle.
3. Engine life increases due to balanced power output.
Finally I extend my gratefulness to one and all who are
directly or indirectly involved in the successful completion of
this project work.
REFERENCES
1. Dr. Wolfgang Reik, Dr. Roland Seebacher, Dr. Ad Kooy, “Dual mass
flywheel”
2. 7. Dr. Albert Albers, “Advanced Development of Dual Mass
Flywheel (DMFW) Design - Noise Control for Today's
Automobiles
3. Kevin Ludlum, “Optimizing Flywheel Design for use as a Kinetic
Energy Recovery System for a Bicycle” In 2011, Maxwell von
Stein
4. S H Salter “Power conversion mechanisms for wave energy”,
University of Edinburgh, Edinburgh, UK
5. Dr. Robert Hebner, Director/Principal Investigator, Center for
Electro mechanics; “Low-Cost Flywheel Energy Storage for
Mitigating the Variability of Renewable Power Generation”,
University of Texas at Austin
6. Patent No: US 8393, United state patent, 03 Feb 2010, “Dual mass
flywheel”, 12 March 2013
7. EP 1046 834 A2, Park, European patent application, 16.03.2000,
“Dual mass flywheel for automotive vehicles”, 25.10.2000
AUTHOR PROFILE
Prof. R.S. Shelke, ME Mechanical, Professor of Mechanical Engineering,
Sir Visvesvaraya Institute of Technology, Nashik, Savitribai Phule Pune
University abbreviated as Pune University
IV. CONCLUSION
It is observed that there is approximately 7 to 8 %
increase in power output by using the Dual mass flywheel
and also observed that the Dual mass flywheel is 5 to 6 %
efficient than the conventional flywheel which will also
result in increasing fuel economy of the engine.
Digambar G. Dighole completed BE (Mechanical Engineering) &
ACKNOWLEDGEMENT
I place on record and warmly acknowledge the continuous
encouragement, invaluable supervision, timely suggestions
and inspired guidance offered by my project guide Prof. R.S.
Shelke Department of Mechanical Engineering, Sir
Visvesvaraya Institute of Technology, Chincholi, Nasik, in
bringing this report to a successful completion. I am grateful
to Prof. V. M. Rane Head of the Department of Mechanical
Engineering, and Also Prof. V. L. Kadlag, Workshop
Superintendent Department of Mechanical Engineering for
permitting me to make use of the facilities available in the
department to carry out the project successfully. My deep
gratitude to Dr. G. B. Shinde, Principal of S.V.I.T.,
Chincholi, Nashik, who always been playing a great role in
all round development of student.
Last but not the least I express my sincere thanks to all of
my friends who have patiently extended all sorts of help for
accomplishing this undertaking.
Most importantly I would like to express my sincere gratitude
towards my Family for always being there when I needed
them most.
appearing in ME Mechanical (Design Engineering) from Sir Visvesvaraya
Institute of Technology, Nashik, Savitribai Phule Pune University abbreviated
as Pune University.
digambar.dighole@gmail.com
Mo. No. 9921146501
331
ISSN: 2278 – 7798
All Rights Reserved © 2016 IJSETR