7th International CTI Symposium
`„Innovative Automotive Transmissions“
`1 – 4 December 2008
`
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`
`Career biography
`
`
`
`Presenter’s
`Name
`Company
`Professional
`Career
`
`Current position;
`Responsibilities
`
`
`Dr.-Ing. Wolfgang Reik
`LuK GmbH & Co. oHG
`1968
`Studies of physics at the University of Karlsruhe
`
`
`1979
`Engineering degree from the Institut für Werkstoffkunde
`I (Materials Engineering Institute 1) at the University of
`Karlsruhe
`
`Dr. Reik joined LuK in Bühl, a supplier to the automotive
`industry and a specialist for clutches and passenger car
`drivetrain solutions. Dr. Reik held various entry-level
`positions at LuK and was later appointed manager of the
`testing department.
`Executive Vice President for Research & Development
`
`Dr. Reik has also been responsible for managing the
`Automotive Advanced Development department for the
`Schaeffler Group which consists of INA, LuK and FAG
`Executive Vice President LuK Group Research &
`Development
`Executive Vice President Advanced Development Schaeffler
`Group Automotive
`
`
`
`1979
`
`
`
`1989
`
`2004
`
`
`
`
`Valeo Exhibit 1115, pg. 1
`
`

`
`The centrifugal pendulum absorber
`Calming down the drivetrain
`Dr.-Ing. Wolfgang Reik
`LuK GmbH & Co.OHG
`Bertrand Pennec
`LuK GmbH & C.OHG
`
`
`
`Introduction
`
`Rising oil prices, the increasing shortage of crude oil resources and the harmful effects of
`CO2 on climate warming are forcing vehicle manufacturers to develop drivetrains with
`significantly better fuel consumption. The conventional drivetrain based on an internal
`combustion engine is coming under additional pressure by the possibilities of electric-only
`running that have now come within tangible reach. It is only the fact that battery capacity
`remains limited that is delaying the introduction of electric cars.
`In order to give the internal combustion engine a chance of survival in the long term, the poor
`efficiency of current drivetrains must be drastically improved.
`The fact that barely more than 20% of the inherent fuel energy reaches the wheel and can
`therefore be used for driving will be unacceptable in future.
`Engines and transmissions must therefore be refined to achieve maximum efficiency.
`Almost all the measures that are being discussed in this context and are conceivable
`increase the irregularities in torque and speed affecting the crankshaft.
`• Higher power/torque per unit of cylinder capacity
`• Higher average pressures
`• New, fuel-efficient combustion processes
`• Fewer cylinders with identical power
`• Generous torque curves, allowing operation at the lowest possible speed
`The only way of holding the irregularity at its current level is through considerably greater
`mass moments of inertia of the flywheel masses. This would, however, come in conflict with
`the requirements for lightweight construction.
`While the greatest potential lies in the engine with its efficiency of barely more than 20%,
`improvements are also necessary in transmissions, whose efficiency is of the order of 90%
`depending on the type. The causes of power loss must be optimized or completely removed.
`• Low friction in bearings and tooth meshes
`• Reduced splashing losses
`• Optimized hydraulic components such as pumps
`• Replacement of hydraulic actuators by optimum efficiency, electromechanical
`components
`These measures, however, make it more difficult for the drivetrain to damp out the vibrations
`generated by the engine irregularity and thus avoid rattle and boom noise. Current torsion
`dampers would no longer appear adequate to this task.
`Drivetrain developers are therefore confronted with the situation where urgently required
`measures to reduce consumption cannot be effectively implemented because the drivetrain
`vibrations can no longer be overcome.
`Many vehicle manufacturers who have clearly recognised this problem have therefore set
`themselves the task of developing new isolation and damping concepts since the
`conventional torsion dampers currently used in the dual mass flywheel and converter lockup
`clutches, are reaching their physical limitations.
`
`
`Valeo Exhibit 1115, pg. 2
`
`

`
`Requirements for vibration isolation in modern drivetrains.
`
`
`
`Engine development can look back on considerable progress in the last decade [1]. Engine
`torque relative to engine capacity has significantly increased and the curves have become
`more generous, i.e. such high torques are available at speeds of barely more than 1000 rpm
`that fuel-efficient driving is possible and even promoted in these ranges (Figure 1).
`
`
`-600 1/min
`
`year 2010
`
`year 2000
`
`+ 200 Nm
`(+63%)
`
`550
`
`500
`
`450
`
`400
`
`350
`
`300
`
`250
`
`200
`
`150
`
`100
`
`50
`
`Engine Torque [Nm]
`
`0
`500
`
`1000
`
`1500
`
`2000
`
`2500
`
`3000
`Speed [1/min]
`
`3500
`
`4000
`
`4500
`
`5000
`
`5500
`
`
`
`
`
`Fig. 1: Increase in Engine Torque from year 2000 to 2010
`
`Based on the Example of a 4 Cylinder, 2.0 litre Diesel Engine
`
`
`
`This leads, unfortunately, to correspondingly higher irregularity at the crankshaft (Figure 2).
`
`
`Year 2010,
`520 Nm
`Conventional DMF design
`
`Engine
`Transmission
`
`1600
`
`1400
`
`1200
`
`1000
`
`Speed [1/min]
`
`800
`
`Year 2000,
`320 Nm
`Conventional DMF design
`
`Engine
`Transmission
`
`1600
`
`1400
`
`1200
`
`1000
`
`800
`
`Speed [1/min]
`
`600
`
`0
`
`0.02
`
`0.04
`
`0.08
`0.06
`Time [s]
`
`0.1
`
`0.12
`
`0.14
`
`600
`
`0
`
`0.02
`
`0.04
`
`0.08
`0.06
`Time [s]
`
`0.1
`
`0.12
`
`0.14
`
`
`
`
`
`Fig. 2 Increase in Engine Excitation and Resulting Transmission torsional vibrations
` Based on the Example of a 4 Cylinder, 2.0 litre Diesel Engine
`
`Valeo Exhibit 1115, pg. 3
`
`

`
`i.e. designed for lower
`Since transmissions have been “optimized” over the same period,
`friction, there is now a situation where even better isolation is required under higher
`excitation levels in order to fulfil the increased comfort requirements (Figure 3).
`
`
`Year 2010,
`520 Nm
`Conventional DMF design
`
`Engine
`Transmission
`
`Target: transmission
`
`1000
`
`1500
`
`2500
`2000
`Speed [1/min]
`
`3000
`
`3500
`
`
`
`8000
`
`7000
`
`6000
`
`5000
`
`4000
`
`3000
`
`2000
`
`1000
`
`0
`
`Accel. Amplitude 2ndorder [rad/s2]
`
`Year 2000,
`320 Nm
`Conventional DMF design
`
`Engine
`Transmission
`
`Target: transmission
`
`1000
`
`1500
`
`2500
`2000
`Speed [1/min]
`
`3000
`
`3500
`
`8000
`
`7000
`
`6000
`
`5000
`
`4000
`
`3000
`
`2000
`
`1000
`
`0
`
`Accel. Amplitude 2ndorder [rad/s2]
`
`
`
`Fig. 3 Increase in Engine Excitation and Resulting Transmission torsional vibrations
`Based on the Example of a 4 Cylinder, 2.0 litre Diesel Engine
`
`
`If this is to be solved with the existing damper technology, which uses torsional elasticity to
`give decoupling, considerably larger torsion angles must be achieved in order to
`simultaneously give better isolation at lower speeds.
` Figure 4 shows in a qualitative manner how the damper capacity must be increased in order
`to meet these challenges [2]. This would require considerably greater spring volumes, for
`which no space is available. As a completely separate issue, it would hardly be possible to
`achieve comfortable driving with such enormously long curves, since the torsional damper
`would extremely wind up under full load.
`
`lower springrate
`
`same spring rate
`2010 torque
`
`2010
`
`2000
`
`700
`
`600
`
`500
`
`400
`
`300
`
`200
`
`100
`
`Torque [Nm]
`
`0
`
`0
`
`10
`
`20
`
`30
`
`40
`
`60
`50
`Wind-up angle [°]
`
`70
`
`80
`
`90
`
`100
`
`Fig. 4: New Requirements for Damper Design for modern engine
`
`
`
`Valeo Exhibit 1115, pg. 4
`
`

`
`Physical possibilities for vibration isolation
`
`Apart from torsional elasticity-based decoupling using a torsional damper, there are other
`possibilities for vibration isolation. The fundamental principles are shown in Figure 5.
`
`
`
`Transmission
`
`Engine
`
`Speed
`
`Speed
`
`Speed
`
`Speed
`
`Speed
`
`Speed
`
`DSpeed
`
`DSpeed
`
`DSpeed
`
`DSpeed
`
`DSpeed
`
`DSpeed
`
`Engine
`
`Transm. Vehicle
`
`Clutch
`
`Drive
`shafts
`
`Clutch
`damper
`
`Additional
`inertia
`
`DMF
`
`Slip
`control
`
`Vibration
`absorber
`
`Centrifugal
`pendulum
`absorber
`
`Fig. 5: Different ways to achieve vibration isolation
`
`
`Prior to the introduction of the dual mass flywheel, only torsional dampers were used in
`clutch discs and were completely adequate in terms of isolation effect at higher speeds.
`Since the resonance speed of drivetrain thus equipped is in the range between 1500 and
`2000 rpm, isolation cannot be achieved below about 2000 rpm, a speed that is now
`particularly important for fuel-efficient driving.
`Improvements can be achieved by providing an additional mass moment of inertia on the
`primary side. The irregularity of the engine is reduced in line with this additional mass. In
`order to fulfill current isolation requirements, however, unrealistically high additional masses
`would be required.
`About 20 years ago, the problem was solved by the dual mass flywheel, in which a well-
`dimensioned torsional damper was arranged between two masses. As a result, the
`resonance speed was pushed below the idling speed.
`Good isolation of the torsional vibrations was thus possible at lower speeds from approx.
`1000 rpm.
`Over two decades, the dual mass flywheel was the panacea for vibration problems and
`drivetrain noise and was successfully implemented in manual transmissions across whole
`classes of vehicles.
`In automated transmissions with converters, in which the dual mass principle cannot be
`implemented so easily, the specific slip in the lockup clutch was utilised in addition to the
`conventional torsional dampers in the converter lockup clutches.
`According to Coulomb’s Law of Friction, the frictional force is not dependent on the slip
`speed. A slipping transmission element does not transmit any torque variations. The slippage
`required is directly dependent on the magnitude of the torsional vibrations which lead to
`relatively high losses at low speeds.
`
`Valeo Exhibit 1115, pg. 5
`
`

`
`Slip is therefore generally used in conjunction with a torsional damper in order to improve its
`isolation effect. However, losses due to slip can reach several percent and will presumably
`no longer be accepted in future.
`Vibration absorbers can be considered as a further measure. They are elastically coupled
`additional masses that lie outside the torque flow path. This type of absorber can, at its own
`resonance frequency, generate oscillations that directly counteract and thus cancel out the
`vibration being generated. This effect only occurs, unfortunately, at the absorber frequency
`and thus only at a very specific speed. In addition, two new resonance points are created, so
`a simple absorber can only be applied in a very limited way to remove torsional vibrations.
`There is therefore a need for a speed-adaptive absorber whose resonance frequency adapts
`automatically to the speed and thus the excitation frequency.
`
`Theory of the centrifugal pendulum absorber
`
` particularly effective method of reducing vibrations is an absorber that comprises a mass
`coupled by means of springs. When correctly adjusted, this mass generates vibrations that
`counteract the excitation and thus act to cancel out the vibrations at the point to which the
`absorber is attached. However, the absorber only acts at a certain frequency, namely its
`natural frequency, which is determined by
`ω = √ k/m. At lower or higher excitation
`frequencies, the absorber does not act as desired and can even act to amplify the problem.
`An absorber of this type with a resonance frequency proportional to the speed is very difficult
`to achieve by means of springs and masses. The example in Figure 6 shows how this can
`nevertheless be achieved by replacing the springs.
`
`
` A
`
`W
`
`l
`
`2
`
`W(cid:215)
`l
`
`lr
`
`r (cid:215)
`
`W=w
`
`r
`
`Centrifugal
`force
`
`=w
`
`l
`
`g
`
`lg
`
`=w
`
`kAbsorber
`
`Vibration
`absorber
`
`Excitation
`
`vehicle
`
`mk
`
`Absorber
`
`Absorber
`
`=w
`
`Fig. 6: From Damper to pendulum absorber
`
`
`
`
`
`
`
`The model of such an absorber arrangement is shown on the left of the picture. The
`alternating excitation would excite the vehicle to horizontal vibrations. If the absorber is
`precisely matched to the excitation frequency, it generates vibrations that are precisely in
`opposition to the excitation frequency. The vehicle itself is brought to rest. Such absorbers
`are used in many mechanical installations where the requirement is to eliminate a very
`specific disruptive frequency.
`
`Valeo Exhibit 1115, pg. 6
`
`

`
`A mechanically equivalent system can be achieved by converting the spring absorber into a
`pendulum (Figure 6, centre). In both cases, there is an exchange of kinetic energy and
`potential energy during the vibrations.
`In the normal absorber, the potential energy is held in the springs of the absorber, while in
`the pendulum it is held in the mass which was raised by a certain amount in the gravitational
`field of the Earth. The pendulum does not therefore require springs.
`However, the pendulum initially has a very defined natural frequency and is therefore equally
`unsuitable for broadband absorption.
`The formula for the natural frequency ω = √ g/l shows that this is dependent only on the
`length of the pendulum and the force of gravity, better described as the gravitational field of
`the Earth. On the Moon, the same pendulum would vibrate much more slowly. All
`mathematical and physical relationships still apply if the gravitational field of the Earth is
`replaced by any other field. It would be possible to use, for example, electrical or magnetic
`fields, with which absorbers could be created whose frequency could be adjusted by
`adjusting the strength of the field.
`In drivetrains where the excitation frequency is always proportional to the speed of the
`internal combustion engine, there is another possibility whose principles were laid down
`about 80 years ago.
`If the pendulum is mounted on a rotating disc, the acceleration due to gravity g is replaced by
`centrifugal acceleration a = r Ω2 (Figure 6, right).
`The natural frequency of such a pendulum is then directly proportional to the speed. It is thus
`possible to achieve broadband absorbers that can cancel out, or at least significantly
`attenuate the effect of whole excitation orders over a wide speed range.
`This is the simpler part of the theory of the centrifugal pendulum absorber, that is only valid
`for small pendulum angles, for which sin α = α is fulfilled. In general, this precondition is not
`met.
`According to the theory behind the absorbers, the amplitude of the absorber increases until a
`force curve opposing the excitation is established. In the least favourable case, absorber
`components may be destroyed if the amplitudes become too great. In order to limit the
`amplitudes, various measures must be implemented.
`First, the pendulum mass selected must be large enough that sufficiently large
`counterexcitations can be created at all. The effect of the centrifugal pendulum absorber
`becomes smaller and smaller at low speeds since the centrifugal acceleration becomes
`smaller. At low speeds, the pendulum tries to compensate this through particularly large
`oscillation amplitudes.
`Normally, path curves are therefore selected in preference that deviate from the arc at a
`larger angle. The aim here is to ensure that the pendulum frequency remains constant up to
`amplitudes of 45 o. If even higher amplitudes occur, the natural frequency is then specifically
`detuned such that the amplitudes remain limited. This prevents striking noise or even
`destruction.
`In a closer mathematical analysis, further forces must be taken into consideration. In
`particular, the Coriolis force induces additional forces that, under large vibration angles, lead
`to deviations in the absorption force curve and, for example, prevent complete absorption or
`elimination.
`Actual centrifugal pendulum absorbers can therefore only be designed by means of
`simulations taking account of all the forces acting on the pendulum.
`
`
`
`Valeo Exhibit 1115, pg. 7
`
`

`
`History of the centrifugal pendulum absorber
`
`The mathematical principles of the centrifugal pendulum absorber were established around
`1930. Even the first design proposals [3] were made at that time. Salomon (1932) envisaged
`a system of rollers oscillating in circular recesses (Figure 7).
`
`
`
`
`Fig. 7: Centrifugal pendulum absorber with oscillating rollers in a patent by Salomon, 1932
`
`Where pendulum masses must also rotate during oscillation, however, this does not give
`optimum conditions, as will be shown later.
`
`Sarazin (1937) proposed a bifilar suspension arrangement [4] in which each point of mass
`describes the same (desired) path (Figure 8).
`
`
`Modern designs of the centrifugal pendulum absorber are a further development of this
`suspension arrangement. Such centrifugal pendulum absorbers were used in aircraft engines
`during World War 2 (Figure 9).
`
`Fig. 8: Bifilar suspension arrangement by Sarazin (1937)
`
`
`Fig. 9: Centrifugal pendulum absorber with bifilar suspension on the crankshaft of an aircraft engine (R1820
`Cyclone) from Pratt & Whitney [6]
`
`
`
`
`
`Valeo Exhibit 1115, pg. 8
`
`

`
`
`
`In car engines (Figure 10), these pendulums were also generally installed on a crankshaft
`web.
`
`
`Fig. 10: Crankshaft used in the engine with two pendulum attached (left) and one of the pendulum absorbers
` used on the crankshaft (right), Ford Motor Co [6]
`
`
`
`Following this, no further developments took place on the centrifugal pendulum absorber for
`a long period. For a time, it was possible to overcome the vibration problem using other,
`simpler solutions.
`It is only in recent years that the centrifugal pendulum absorber has come back on the scene,
`as the performance and thus the irregularity of internal combustion engines has increased,
`while at the same time the requirements for comfort levels have grown.
`Several attempts have been made in recent years to revive the centrifugal pendulum
`absorber. An absorber based on the Salomon rollers was offered under the name “Rattler“ by
`TCI Automotive
`(Figure 11).
`
`
`
`
`
`
`
`
`
`
`Fig. 11: Absorber with rollers as a centrifugal pendulum absorber [8]
`
`
`Freudenberg made attempts, by means of pendulums with bifilar suspension in a flywheel, to
`directly reduce the irregularity of the crankshaft (Figure 12). However, pendulum masses of
`several kilograms were required since the pendulums had to counteract the total maximum
`torque peaks during ignition.
`While this system was effective in principle, it could not be successfully implemented.
`Based on this experience, it became clear that future requirements for vibration isolation
`cannot be fulfilled with an acceptable outlay by means of centrifugal pendulum absorbers on
`their own.
`Efforts were therefore made to achieve a suitable combination with conventional torsional
`dampers.
`
`Valeo Exhibit 1115, pg. 9
`
`

`
`Figure 13 shows, on the left, the model of a centrifugal pendulum absorber linked directly to
`the flywheel and thus also to the crankshaft. Large pendulum masses are required in order to
`allow compensation of ignition shocks. On the right of the picture , a dual mass flywheel is
`used as a basis and the pendulum is arranged on the secondary flywheel mass. This allows
`a division of labour.
`
`
`
`
`
`
`
`Fig 12: Centrifugal pendulum absorber with bifilar suspension in the flywheel [7]
`
`On flywheel
`
`After torsion damper (DMF)
`
`5 kg
`
`1 kg
`
`Engine
`
`Transmission
`
`DSpeed
`
`Engine
`Transmission
`
`DSpeed
`
`Speed
`
`Speed
`
`Fig. 13: Essential possibilities for locating a centrifugal pendulum absorber
`
`
`
`
`
`
`
`
`
`
`
`
`The dual mass flywheel with its spring coupling gives the first stage of isolation. The
`secondary flywheel mass is typically subjected only to torque amplitudes below 50 Nm, while
`the torque acting directly on the crankshaft is many times the mean engine torque and, in
`diesel engines in particular, may be well over 1000 Nm.
`A centrifugal pendulum absorber arranged on the secondary flywheel mass must, in contrast,
`only compensate the residual irregularity and only requires much smaller masses.
`
`
`
`Design features
`
`Since it has been clarified at which point, namely after a torsional damper, the centrifugal
`pendulum absorber should usefully be arranged, the precise design must now be defined.
`
`Valeo Exhibit 1115, pg. 10
`
`

`
`
`At first, it appears easiest to use rollers in accordance with the design by Salomon (Figure 7).
`A more precise analysis shows, however, that this is not the most effective way since the
`rollers rotate during oscillation and part of the kinetic energy is therefore stored as rotational
`energy (Figure 14),
`
`
`
`Fig. 14: Centrifugal Pendulum Absorbers with Salomon Rollers.
`
`
`
`
`
`and the energy for translational motion is thus lacking. It is only the speed along the path of
`the pendulum that generates centrifugal force and thus contributes to an absorption effect.
`
`m
`
`m
`
`r
`
`w
`
`h
`
`h
`
`rv ; mr
`2
`w=
`
`21
`
`J
`
`2
`=w
`
` J ; mgh
`=
`
`gh
`
`E
`
`kin
`
`=
`
`E
`
`pot
`
`21
`
`34
`
`2
`
`mv
`
`+
`
`21
`
`v
`=(cid:222)
`
`E
`
`kin
`
`=
`
`E
`
`pot
`
`mv
`2
`
`=
`
`mgh
`
`21
`
`v
`=(cid:222)
`
`2gh
`
`
`Fig. 15: A carriage acquires a greater speed on an inclined plane than a roller.
`
`
`
`
`
`In Figure 15 this is shown using the example of an inclined plane. From the same initial
`height on the ramp, the carriage acquires a greater speed than the roller.
`All pendulum arrangements in which rotation of the pendulum itself occurs are therefore not
`an optimum solution. This also applies to the physical pendulum (Figure 16),
`
`Valeo Exhibit 1115, pg. 11
`
`

`
`
`
`Fig. 16: Physical pendulum
`
`in which it is also significant that relatively large elements of the mass are arranged around
`the suspension system (bolt) and thus do not contribute to the pendulum effect.
`The aim must be to allow effective oscillation of the total available mass. The best way of
`achieving this, after the mathematical pendulum that cannot be realised in practice, is a bifilar
`suspension arrangement. In the simplest design, the oscillating mass can oscillate over two
`bolts that are arranged in kidney-shaped recesses in the mass and in the carrier. The shape
`of the holes is selected to give an appropriate pendulum path.
`
`
`
`Figure 17
`
`
`m
`
`m
`
`m
`
`l
`
`L
`
`l
`
`L
`
`l
`
`L
`
`Fig. 17: Movement of bifilar pendulum
`
`
`
`
`
`shows how the total mass moves without rotation. Each point describes the same path, so
`the pendulum can be presented as a point type mass at the centre of gravity moving along
`the curve.
`This indirectly imitates the mathematical pendulum and allows the greatest effect for a given
`mass.
`The pendulum masses are advantageously arranged on both sides of a carrier flange and
`are linked to each other by 2 or 3 rivets such that sufficient axial clearance is present and the
`pendulums can move without external friction and damping.
`
`Valeo Exhibit 1115, pg. 12
`
`

`
`With 4 pendulums each comprising stamped sheet metal parts approx. 5 mm thick, a
`pendulum mass of approx. 1 kg can be achieved, which should be located on the largest
`possible diameters.
`In the dual mass flywheel, the large diameter area is reserved as before for the bow springs.
`The pendulums are located on the flange inboard of these springs and thus act on the
`secondary flywheel mass (Figure 18).
`
`
`primary mass
`
`arc springs
`
`flange
`
`pendulum mass
`
`
`
`Fig. 18: Dual mass flywheel with pendulum absorbers
`
`
`
`
`
`
`
`In the converter, the centrifugal pendulum absorber can be integrated with the torsional
`damper in the lockup clutch. Effort is made here too to locate the pendulums with bifilar
`suspension on the largest possible diameter. Based on the torque flow path, at least 1
`torsional damper must be arranged in front of the centrifugal pendulum absorber (Figure 19).
`
`
`Fig. 19: Torque Converter with Lockup-Clutch with pendulum absorber
`
`
`
`
`
`
`
`Measurements
`
`With a centrifugal pendulum absorber on the secondary flywheel mass of a dual mass
`flywheel, a further improvement in vibration isolation can be achieved. Figure 20 shows,
`using the example of a 4 cylinder diesel engine with 400 Nm, the speed fluctuations of the
`engine and transmission input for various dual mass flywheel types. A zoom of the smaller
`speed variations is shown on the right.
`
`Valeo Exhibit 1115, pg. 13
`
`

`
`Compared with the basic design only containing arc springs and the improved variant with
`inner damper, the centrifugal pendulum absorber replacing the inner damper gives a further
`significant improvement in isolation. Compared with a normal dual mass flywheel, the
`irregularity can be further reduced by more than half. It can be seen directly from the curves
`that, for a specific maximum permissible variation range of the transmission input speed
`required for running free from rattle and boom noise, the minimum engine speed can be
`reduced by several hundred revolutions per minute.
`Even greater benefits apply to the converter and its torsional damper in the lockup clutch,
`since the conventional dampers do not yet include the dual mass flywheel effect.
`
`
`
`Speed Amplitude 2ndorder [1/min]
`
`
`
`Basic DMF
`DMF with ID
`DMF with Pendulum
`
`-63%
`
`-27%
`
`-50%
`
`1000
`
`1500
`
`2500
`2000
`Speed [1/min]
`
`3000
`
`3500
`
`
`
`40
`
`30
`
`20
`
`10
`
`0
`
`Speed Amplitude 2ndorder Sec. [1/min]
`
`200
`
`160
`
`120
`
`80
`
`40
`
`0
`
`Secondary:
`Basic DMF
`DMF with ID
`DMF with Pendulum
`
`Engine
`
`1000
`
`1500
`
`2500
`2000
`Speed [1/min]
`
`3000
`
`3500
`
`Fig. 20: Full Load Simulation – 4 Cyl. Diesel 400Nm
`System comparison basic DMF, DMF with innerdamper and with Pendulum
`
`
`
`
`
`Figure 21 shows not only the speed amplitude of the engine but also of the transmission
`input, which is decisive for boom noise.
`Even a conventional double torsional damper cannot eliminate the turbine natural mode, at
`least at speeds around 1300 rpm. A turbine torsional damper, in which the torsional elasticity
`lies within the torque flow path of the turbine (hence the name) gives a significant
`improvement that is, nevertheless, not sufficient in various vehicles.
`The centrifugal pendulum absorber gives the major benefit here and allows boom-free driving
`even at speeds down to 1000 rpm.
`
`Valeo Exhibit 1115, pg. 14
`
`

`
`Differential with:
`Turbine Damper
`Double Damper
`Double Damper with
`pendulum absorber
`
`Engine
`
`Turbine
`Natural
`Mode
`
`120
`
`110
`
`100
`
`90
`
`80
`
`70
`
`60
`
`50
`
`40
`
`30
`
`20
`
`10
`
`Speed Amplitude Differential [1/min]
`
`0
`1000
`
`1200
`
`1400
`
`1600
`
`1800
`
`2000
`
`2200
`
`2400
`
`2600
`
`2800
`
`3000
`
`Speed [1/min]
`
`
`
`Fig. 21: Full load simulation – 4 cyl. diesel 450 Nm
`System comparison basic torque converter, turbine damper, double damper and double damper with
`pendulum absorber.
`
`
`
`
`
`
`Conclusion
`
`The requirements for fuel-efficient drivetrains are continually increasing as a result of
`discussions about climate warming and scarcity of resources.
`Many of the fuel-efficient drive concepts increase the irregularity of the engine and the
`sensitivity of transmissions to these periodical variations of speed and torque. Improved
`torsional dampers are therefore required. The centrifugal pendulum absorber is an absorber
`whose resonance speed increases in proportion to the speed. In order to keep the pendulum
`size within acceptable boundaries, the centrifugal pendulum absorber should be located on
`the secondary mass of the dual mass flywheel.
`The effect of such pendulums in dual mass flywheels and also in converters is described.
`Significantly improved isolation effects can thus be achieved.
`
`
`
`Literature
`
`[1] Reik, W.: Kupplung, Wandler + Schwingungsdämpfer – Die Bindeglieder zwischen
`Motor und Getriebe bei neuen Antriebsstrangkonzepten, cti-Symposium 2007
`
`
`[2] Müller, B.: LuK Drehmomentwandler – Strategiefähige Wandler für neue
`Automatikgetriebe,
` VDI 2008, Friedrichshafen
`
`[3] Salomon, UK-Patent 401,962 - 1932
`
`[4] Sarazin, UK-Patent 2,079,226 - 1987
`
`[5] McCutcheon, Kimble D.: The Struggle to Develop the R-2800 – „Double Wasp“
`Crankshaft
`
`Valeo Exhibit 1115, pg. 15
`
`

`
`
`[6] McCutcheon, Kimble D.: The Struggle to Develop the R-2800 – „Double Wasp“
`Crankshaft.
`
`
`[7] Jörg B., Werner K., Eckel, H.-G., Der drehzahladaptive Tilger DAT, der
`Techologiesprung im Antriebsstrang, 2001, ATZ N. 9, 758-764
`
`
`[8]
`
`www.tciauto.com
`
`Valeo Exhibit 1115, pg. 16
`
`

`
`7thInternational CTI-Symposium „Innovative Automotive Transmissions“
`1 – 4December2008, Berlin, Germany
`
`The Centrifugal Pendulum Absorber
`Calming down the drive train
`
`Dr. –Ing. Wolfgang Reik, Dipl.-Ing. Bertrand Pennec
`
`Valeo Exhibit 1115, pg. 17
`
`

`
`Increase in Engine Torque & Downspeeding
`Based on the Example of a 4 Cylinder, 2.0 litre Diesel Engine
`
`+ 200 Nm
`(+63%)
`
`-600 1/min
`
`2010
`
`2000
`
`1000
`
`1500
`
`2000
`
`2500
`
`3000
`Speed [1/min]
`
`3500
`
`4000
`
`4500
`
`5000
`
`5500
`
`CTI Symposium -Innovative Automotive Transmissions
`
`550
`
`500
`
`450
`
`400
`
`350
`
`300
`
`250
`
`200
`
`150
`
`100
`
`50
`
`Engine Torque [Nm]
`
`0
`500
`
`Dec. 2008
`Page 2
`
`Valeo Exhibit 1115, pg. 18
`
`

`
`Increase in Engine Excitation & Resulting Transmission vibrations
`Based on the Example of a 4 Cylinder, 2.0 litre Diesel Engine
`
`Year 2010
`520 Nm
`Conventional DMF design
`Engine
`Transmission
`
`1600
`
`1400
`
`1200
`
`1000
`
`800
`
`Speed [1/min]
`
`Year 2000
`320 Nm
`Conventional DMF design
`Engine
`Transmission
`
`1600
`
`1400
`
`1200
`
`1000
`
`800
`
`Speed [1/min]
`
`600
`
`0
`
`0.02
`
`0.04
`
`0.08
`0.06
`Time [s]
`
`0.1
`
`0.12
`
`0.14
`
`600
`
`0
`
`0.02
`
`0.04
`
`0.08
`0.06
`Time [s]
`
`0.1
`
`0.12
`
`0.14
`
`Dec. 2008
`Page 3
`
`CTI Symposium -Innovative Automotive Transmissions
`
`Valeo Exhibit 1115, pg. 19
`
`

`
`Increase in Engine Excitation & Resulting Transmission vibrations
`Based on the Example of a 4 Cylinder, 2.0 litre Diesel Engine
`Year 2000
`320 Nm
`Conventional DMF design
`Engine
`Transmission
`
`Year 2010
`520 Nm
`Conventional DMF design
`Engine
`Transmission
`
`8000
`
`8000
`
`Target: transmission
`
`1000
`
`1500
`
`2500
`2000
`Speed [1/min]
`
`3000
`
`3500
`
`7000
`
`6000
`
`5000
`
`4000
`
`3000
`
`2000
`
`1000
`
`0
`
`Accel. Amplitude 2ndorder [rad/s2]
`
`Target: transmission
`
`1000
`
`1500
`
`2500
`2000
`Speed [1/min]
`
`3000
`
`3500
`
`7000
`
`6000
`
`5000
`
`4000
`
`3000
`
`2000
`
`1000
`
`0
`
`Accel. Amplitude 2ndorder [rad/s2]
`
`Dec. 2008
`Page 4
`
`CTI Symposium -Innovative Automotive Transmissions
`
`Valeo Exhibit 1115, pg. 20
`
`

`
`Requirements for Damper Design
`
`higher damper capacity
`larger wind-up angle
`
`same stiffness
`2010 torque
`
`2010
`
`2000
`
`10
`
`20
`
`30
`
`40
`
`60
`50
`Wind-up angle [°]
`
`70
`
`80
`
`90
`
`100
`
`CTI Symposium -Innovative Automotive Transmissions
`
`700
`
`600
`
`500
`
`400
`
`300
`
`200
`
`100
`
`Torque [Nm]
`
`0
`
`0
`
`Dec. 2008
`Page 5
`
`Valeo Exhibit 1115, pg. 21
`
`

`
`Transmission
`
`Engine
`
`Speed
`
`Speed
`
`Speed
`
`Speed
`
`Speed
`
`Speed
`
`DSpeed
`
`DSpeed
`
`DSpeed
`
`DSpeed
`
`DSpeed
`
`DSpeed
`
`Different ways to achieve vibration isolation
`
`Engine
`
`Transm.
`
`Vehicle
`
`Clutch
`
`Drive
`shafts
`
`Clutch
`damper
`
`Additional
`inertia
`
`DMF
`
`Slip
`control
`
`Vibration
`absorber
`
`Centrifugal
`pendulum
`absorber
`
`Dec. 2008
`Page 6
`
`CTI Symposium -Innovative Automotive Transmissions
`
`Valeo Exhibit 1115, pg. 22
`
`

`
`Vibration Absorber Implementations
`
`kAbsorber
`
`Vibration
`absorber
`
`Excitation
`
`wagon
`
`r
`
`Centrifugal
`force
`
`=w
`
`l
`
`g
`
`lg
`
`=w
`
`mk
`
`Absorber
`
`Absorber
`
`=w
`
`W=w
`
`W
`
`l
`
`2
`
`W(cid:215)
`l
`
`lr
`
`r (cid:215)
`
`Dec. 2008
`Page 7
`
`CTI Symposium -Innovative Automotive Transmissions
`
`Valeo Exhibit 1115, pg. 23
`
`

`
`A History of Centrifugal Pendulum Absorbers
`
`Sarazin-Type: bifilar suspension
`(US-Patent 2,079,226 -1937)
`
`Salomon-type: rollers
`(UK-Patent 401,962 -1932)
`
`Dec. 2008
`Page 8
`
`CTI Symposium -Innovative Automotive Transmissions
`
`Valeo Exhibit 1115, pg. 24
`
`

`
`Centrifugal pendulum absorber with bifilar suspension
`on the crankshaft of an aircraft engine
`
`Dec. 2008
`Page 9
`
`CTI Symposium -Innovative Automotive Transmissions
`
`Valeo Exhibit 1115, pg. 25
`
`

`
`Crankshaft used in the engine with two pendulum attached
`and one of the pendulum absorbers used on the crankshaft
`
`Dec. 2008
`Page10
`
`CTI Symposium -Innovative Automotive Transmissions
`
`Valeo Exhibit 1115, pg. 26
`
`

`
`Absorber with rollers as centrifugal pendulum absorber
`
`TCI Automotive
`(Salomon Rollers)
`
`Dec. 2008
`Page11
`
`CTI Symposium -Innovative Automotive Transmissions
`
`Valeo Exhibit 1115, pg. 27
`
`

`
`Centrifugal pendulum absorber with bifilar suspension
`in the flywheel
`
`Vibracoustic / Freudenberg
`(Bifilar, Sarazin-type)
`
`Dec. 2008
`Page12
`
`CTI Symposium -Innovative Automotive Transmissions
`
`Valeo Exhibit 1115, pg. 28
`
`

`
`Essential possibilities for locating a centrifugal
`pendulum absorber
`On flywheel
`
`After torsion damper (DMF)
`
`5 kg
`
`1 kg
`
`Engine
`
`Transmission
`
`DSpeed
`
`Engine
`Transmission
`
`DSpeed
`
`Speed
`
`Speed
`
`Dec. 2008
`Page13
`
`CTI Symposium -Innovative Automotive Transmissions
`
`Valeo Exhibit 1115, pg. 29
`
`

`
`Centrifugal Pendulum Absorbers with Salomon Rollers
`
`Dec. 2008
`Page14
`
`CTI Symposium -Innovative Automotive Transmissions
`
`Valeo Exhibit 1115, pg. 30
`
`

`
`A carriage acquires a greater speed on an inclined
`plane than a roller
`
`m
`
`m
`
`r
`
`w
`
`h
`
`h
`
`rv ; mr
`2
`w=
`
`21
`
`J
`
`2
`=w
`
` J ; mgh
`=
`
`gh
`
`E
`kin
`
`=
`
`E
`pot
`
`21
`
`34