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The reciprocating piston petrol engine
Published in M.J. Nunney, Light and Heavy Vehicle Technology, 2007
Originally developed in the mid-1980s by Toyota for application to a motor car turbocharged diesel engine, the flywheel with torsional vibration damper or dual-mass flywheel as it is now often termed, has in more recent years become increasingly adopted for petrol engines where manufacturers seek additional refinement for the transmission system. The purpose of the dual-mass flywheel is to reduce the extent to which periodic fluctuations in engine torque are passed on to the transmission system, which otherwise create vibration, noise and can lead to wear of components. Typically noticeable with a dual-mass flywheel installation is therefore a reduction in transmission gear noise at low engine speeds. In this context there is a greater opportunity with a modern five-speed and reverse, all-synchromesh, gearbox for light load rattles to occur between the teeth of the more comprehensive train of constant-mesh gears (Section 18.3).
Dual Mass Flywheel Optimization
Published in Levent Aydin, H Seçil Artem, Selda Oterkus, Designing Engineering Structures Using Stochastic Optimization Methods, 2020
Ümmühan Gümüş, Levent Aydin, Okan Yazici, Samet Kabacaoğlu
By establishing test benches and models, the effects of torsional vibrations on the transmission of a dual-mass flywheel (DMF) and noise and vibration improvements were investigated [2, 13–15]. In a study involving many of the powertrain components, torsional vibration signals were obtained by equal angles sampling and order analysis method. The torsional vibration data are processed and analyzed with the help of MATLAB® program under constant speed conditions, and the order signal of the engine excitation is obtained [13]. In another study, a test setup was established to investigate the effect of DMF on impact-induced clonk noise. Extensive measurements using DMF and the conventional clutch system showed significant differences in vibration and noise values in the driveline, resulting in differences in the number of modes of both parameters [2]. Dual Clutch Transmission (DCT) DQ250 was used to observe and verify the damping ability of the DMF, and the experimental setup was established. In this experiment, various conditions were created and tested for the vehicle, which can be given as an idle, working and climbing condition. According to the obtained test data, different engine revs and loads affect the damping ability of the DMF. As the load and rev on the engine increases, the dual mass flywheel has been observed to have a better damping ability [14]. Displacement measurements on DMF have been developed with a linear variable differential transformer (LVDT) mounted on a vehicle. Unlike other experimental studies, the data are obtained by using sensors, power and Bluetooth TM node connection and transmits the data via Bluetooth technology. It is possible to obtain more direct results with this measurement system developed for DMF.
Balancing and vibrations
Published in Allan Bonnick, Automotive Science and Mathematics, 2008
A flywheel that incorporates a torsional vibration damper is known as a dual mass flywheel. In these flywheels there are two main masses that have a small amount of freedom to move relative to each other. The relative movement is controlled by springs, and friction between the two masses provides the damping effect.
Modelling of the operation of a Dual Mass Flywheel (DMF) for different engine-related distortions
Published in Mathematical and Computer Modelling of Dynamical Systems, 2018
A continuous advancement of the automotive industry inevitably forces an increase in the driving comfort. In terms of the suspension system, the matters related to the driving comfort have been gradually improved. A series of improvements has been introduced in the intake/exhaust systems to reduce the noise level. Modern drivetrains have been equipped with a Dual Mass Flywheel (DMF). The reason for this was that fact that the torsion dampers fitted in regular clutch discs have reached their operating limit. The increase in the engine power and torque exceeded the capacity of classic torsion damping. Since mid 1980s of the last century, the technology of dual mass flywheels has been continuously improved [1–7].