International Conference on Global Trends in Engineering, Technology and Management (ICGTETM-2016)
Dual Mass Flywheel - A Better Driving Experience by
Reducing Vibration
Dattatray B. Vaitkar1
P.N.Ulhe 2
(M.E. Student)
(Asst. Professor)
Mechanical Engineering Department, SSBT’s College Of Engineering, Bambhori,North Maharashtra
University, India.
Abstract— The dual mass flywheel (DMF) can create
an improved driving experience for manual shift
vehicles. Vibrations and noises that occur during
vehicle operation are absorbed. Fuel consumption is
reduced. This results in economical driving
comfort.Dual mass flywheel is a multi-clutch device
which is used to dampen vibration that occurs due to
the slight twist in the crankshaft during the power
stroke .When the power stroke subsides, the crankshaft
untwists. One wouldn't think a crankshaft would twist
to any significance, but any piece of metal always
deflects a little when a force is applied to it. The rate
that these vibrations occur is referred to as the
torsional frequency. Transaxles experience torsional
vibrations also. When torsional frequencies of the
crankshaft match those of the transaxle an effect
known as torsional resonance occurs, which may
cause excessive wear on the drivetrain components.
Keywords — DMF,Multi-clutch,Damper, Drivetrain.
1.
INTRODUCTION
The dual mass flywheel (DMF) can create an
improved driving experience for manual shift
vehicles.The main function of the dual mass flywheel
is to absorb engine vibrations before they are
transmitted to the driveline, where they may create
gear rattle or excessive wear. To achieve this, the
conventional flywheel is divided into two sections.
The primary section is attached to the crankshaft. The
primary and secondary sections are connected through
springs to isolate engine vibrations from being
transmitted to the transmission. The clutch is bolted
onto the secondary section of the flywheel.
.
1.2 Why to Use Dual Mass Flywheel
The periodic combustion cycles of a 4-stroke
engine create torque fluctuations which causes
torsional vibration to be passed down the drivetrain.
The resulting noise and vibration, such as gear rattle,
body boom and load change vibration, results in a
torsional vibration caused by the engine’s rotating
mass. Owing to its integral spring/damper system, the
DMF almost entirely absorbs this torsional vibration.
The result: very good vibration damping.
Crankshaft torsional vibration occurs because each
power stroke tends to slightly twist the crankshaft.
When the power stroke subsides, the crankshaft
untwists. One wouldn't think a crankshaft would twist
to any significance, but any piece of metal always
deflects a little when a force is applied to it. The rate
that these vibrations occur is referred to as the
torsional
frequency.
Transaxles
experience
torsional vibrations also. When torsional frequencies
of the crankshaft match those of the transaxle an effect
known as torsional resonance occurs, which may
cause excessive wear on the drivetrain components.
.
2. Advantages of DMF over CF
HAVING TWO DIFFERENT MASSES; TWO
DIFFERENT SECTIONS, ISOLATES VIBRATION IN
THECRANKSHAFT FROM PASSING ON TO THE
SECOND MASS TO SOME EXTENT.
THEREBY
PREVENTING
UNDESIRABLE
VIBRATIONS IN THE GEAR BOX, THEREUPON
PREVENTING GEARRATTLE
IMMEDIATE REACT TO INCREASED LOAD
AMPLITUDEDUE TO THE EXISTENCE OF A
MEDIUM IN DMF, BETWEEN PRIMARY AND
SECONDARYMASS; AND CONFIGURATION OF
THROTTLE GEOMETRY DMF CAN BE ADAPTED
TO DIFFERENTREQUIREMENTS BETTER THAN
CFS
decrease in both cabin and driving comfort. The
objective when developing the DMF was therefore to
isolate as much of the drivetrain as possible from the
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3.1.3 Bearing
Large and small ball bearing: The primary mass is
fitted with a turned hub on which the large-size ball
bearing is fitted.
3.1.4 Flange
The task of the flange is to transfer torque from the
primary mass via the arc springs to the secondary
flywheel; in other words, from the engine to the clutch.
.
Fig.1 CF (SMF) VS DMF
3.1.5 Friction control disc
During the start-up process, the DMF operates briefly
3. Dual Mass Flywheel (DMF)
The Dual Mass Flywheel (DMF) is installed
between the engine and the transmission along with
in the resonant frequency range.
3.1.6 Arc springs
The arc spring does the function of damper. The arc
the clutch cover and clutch disc.
3.1Structure of Dual Mass Flywheel
spring is also called as a heart of DMF.The material
used for arc spring is60Si2MnAspringsteel
Fig.2AStructure of Dual Mass Flywheel
3.1.1 Primary Mass
The primary mass or flywheel is connected to the
crankshaft of the engine.
Fig.4 Arc Spring with Different Stiffness
3.1.2 Secondary Mass
3.2 Materials and Properties of Arc Sprin
The engine torque is transferred from the primary
mass to the secondary mass via the arc springs and the
The material used in this investigation is 60Si2MnA
spring steel;
flange.
T Table.1 Design Parameters of Arc Spring
Fig. 3 Structure of Dual Mass Flywheel
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higher
comfort
are
fully
met.
Table.2 Material property of 60Si2MnA
4. Working Principle of Dual Mass Flywheel
The functioning principle of a DMF is simple, yet
efficient. Owing to the additional mass on the
transmission input shaft, the vibration torque range,
Fig.6 Transfer of Torsional Vibrations in DMF
As shown in fig.6 the engine vibrations are reduced
before they are transmitted to the driveline.
which is normally between 1,200 rpm and 2,400 rpm
with original torsion dampers, is moved to a lower
resonance speed range. This ensures excellent
damping of engine vibration even at idle speed.
Fig.7 Working Principle of Dual Mass Flywheel
4.1 With and without Dual Mass Flywheel
Fig 5. Working Principle of Dual Mass Flywheel
1 Engine
2 Clutch
3 Transmission
4 Torsion dampers
5 Primary mass
6 Secondary mass
7 Flywheel
The spring/damper system of the DMF filters out
the torsional vibrationsinduced by the engine as far as
torsional vibration caused by the engine. This prevents
possible from the rest of the drive train. A
gearbox components knocking against each other –
conventional system only satisfies this requirement at
rattling does not occur and the driver’s demands for
high engine speed, because the attainable torsion
Fig.8 Dual Mass Flywheel Arrangement
The goal of torsion damper development is to keep
damper spring rates lead to naturalfrequencies which
are always within the normal driving range.This
unsatisfactory situation led to the development of a
new torsiondamper concept - the dual mass flywheel
(DMFW). This design shifts partof the flywheel
inertia to the transmission input shaft and drastically
lowersthe torsion damper spring rate by introducing
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new spring designs (Figure5.5), thus reducing the
Different compression pressures in various
resonance speed to very low engine speeds.
cylinders.
5. Advantages of Dual Mass Flywheel
Extreme vibration due to worn drivetrain
Elimination of gear rattle
components
Reduced drivetrain noise
6.1 Applications of Dual Mass Flywheel
The DMF is used in luxury cars such as Ferrari 458,
Reduced shifting frequency
Less synchronizer wear
Jaguar XJ, Audi A3 2.0TDI 140 etc.
Lower engine operating speeds save fuel and reduced
Conclusion
emissions
In this way the use of Dual Mass Flywheel with the
Less drivetrain torque fluctuation
Less axial vibrations
utilization of Damping System we can say that the
Long service life
DMF gives the new way of driving experience by
lowering the vibration and used in the most of the
Smooth start/stop performance
Outstanding vibration damping throughout the entire
recent Cars. A vehicle with a DMFW offers increased
fuel economy if the following conditions are met.
rpm range
The vehicle manufacturer reduces idle speed.
5.1Disadvantages of Dual Mass Flywheel
The driver adopts economical driving habits by
Hard to test
driving in higher gears at lower engine speeds both of
Impossible to machine
these factors can be achieved without loss of driving
Costly
comfort. The compact DMFWs offer full dual-mass
5.2An Experimental Case-Study
flywheel function and, therefore, improved noise
An experimental case-study on Dual Mass flywheel
gives the following results at different load condition.
This is shown in tabulated form as follows;
Sr.No.
Load
(gm)
Speed
Torque
Power
Efficienc
y
Acceler
ation
1
1500
1315
0.47088
64.8516
31
32
2
2000
1275
0.62784
83.8386
40
40
3
2500
1245
0.78485
102.3324
49
50
4
3000
1205
0.94176
118.8535
57
63
5
3500
1185
1.09872
136.3616
66
80
6
4000
1155
1.25568
151.8958
74
100
7
4500
1020
1.41264
150.9090
77
125
control for the customer; with only minimal cost
increases when compared to conventional systems.
ACKNOWLEGEMENT
I sincearly thanks to my guide Assi.Prof. P.N.Ulhe
sir (SSBT’S College of Engg. Bambori Jalgaon.).
Who encourage me continuously for this conference.
At last I thanks to Michael Shell and other
contributors for developing and maintaining the IJETT
LaTeX style files which have been used in the
preparation of this template.
REFERENCES
[1]
[2]
6. Possible Causes of Failure of Dual Mass
[3]
Flywheel
Frequent stalling of the engine / driving at
[4]
extremely low engine speeds.
[5]
ISSN: 2231-5381
A Textbook of Theory of Machines by R. S. Khurmi and J. K.
Gupta – Torsional Vibrations (Page no. 972)
A Textbook of Machine Design by R. S. Khurmi and J. K.
Gupta – Flywheel (Page no. 776)
Dr.-Ing. Albert Albers,: Advanced Development of Dual Mass
Flywheel (DMFW) Design - Noise Control for Today's
Automobiles
ZF Services GmbH Obere Weiden 12 · 97424 Schweinfurt ·
Germany Borgwardstr. 16 · 28279 Bremen · Germany
Govinda and Dr. Annamalai, K:VIT University, Chennai,
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International Conference on Global Trends in Engineering, Technology and Management (ICGTETM-2016)
[6]
[7]
[8]
Online: 2347, 2014, pp. 3 54 1 , © IASTER 2014 4904:
Design and Analysis of Arc Springs used in Dual Mass
Flywheel
Sameer More, Pravin Medankar, Prof.Mahesh Nagargoje:
International Journal of Innovative Research in Science,
Engineering and Technology Vol. 4, Issue 3, March 2015 Design and Development of Dual Mass Flywheel System
Payam Bighal: High Efficiency Heavy Duty Truck Engine Advantages of DMF over CF
Schaeffler Automotive Aftermarket GmbH & Co. KG
September 2013 - Dual Mass Flywheel Technology
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