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- Irfan, Muhammad, 1986, et al.
(författare)
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Constrained Lagrangian Formulation for Modelling and Analysis of Transmission Synchronizers
- 2015
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- An engineering model of a generic synchronizer is considered. The generic synchronizeris modeled consisting of the selector sleeve with engaging teeth and frictional cone, thesynchronizing ring with blocker and the gearwheel with engaging teeth. It is assumed thatfor the sleeve and synchronizing ring translational and rotational motions are feasible, forthe gearwheel only rotational motion is feasible. The motion of the generic synchronizer isperformed under the external and internal loads. The external loads comprise the vehicleresistance torque and the control force applied to the sleeve and the drag torque due to theclutch. The internal loads comprise the forces and torques arises due to interactionbetween the sleeve, the synchronizing ring, the gearwheel as well as oil splash during thesynchronization process. A feasible synchronization process of a generic synchronizer isdivided into four main phases: pre-synchronization, main synchronization, blockertransition (indexing for the ring), and engagement. Pre-synchronization and blockertransition are further divided into several sub-phases. The generic synchronizer is fullyparametrized and together with description of all phases constitutes kinematics ofsynchronization process in question.Due to the nature of synchronization process in transmission system a motion of asynchronizer mechanism is subjected to unilateral or/and bilateral constraints imposed ongeneralized coordinates or/and generalized velocities of the synchronizer. ConstrainedLagrangian Formalism (CLF) has been proposed as an approach for developingmathematical and computational models of a generic synchronizer dynamics. The CLFgives possibility to formulate direct dynamics, semi-inverse dynamics and inversedynamics problems for a generic synchronizer in unified and efficient way. It is shown thatCLF can be promising and useful for advanced dynamic analysis of the existingsynchronizer mechanisms and to design novel optimized ones.In the present report mathematical and computational models of a generic synchronizerwith five degrees of freedom have been developed using CLF. Application of CLF on themodelling of the synchronization process gives system of differential-algebraic equations(DAE). Analysis of the generic synchronizer performance diagrams has shown that the CLFbased model is able to predict the synchronization process characteristics reasonably well.The developed model has been validated by using measurement data from test rig at CVAB Scania. Performance of the generic synchronizer is also analyzed in case of drivelinevibrations. Sensitivity analysis of the synchronizer mechanism performance with respect tocone angle, coefficient of friction, maximum value of shift force and rate of applying shiftforce has been done.Next, the developed models will be used to get further insight into synchronizer design andits performance diagrams with aid of global sensitivity analysis and Pareto optimization.
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| 2. |
- Irfan, Muhammad, 1986, et al.
(författare)
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Modelling of Heavy Vehicle Transmission Synchronizer using Constrained Lagrangian Formalism
- 2015
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Ingår i: In Proc. of the International Conference on Engineering Vibration, Ljubljana, 7 - 10 September ; [editors Miha Boltežar, Janko Slavič, Marian Wiercigroch]. - EBook. - Ljubljana: Faculty for Mechanical Engineering, 2015. - 9789616536974 ; , s. 28-37
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Konferensbidrag (refereegranskat)abstract
- Robust and efficient synchronizers are keys elements to ensure good gear shift in heavy vehicles. In order to improve existing as well as develop new synchronizers, efficient simulation tools are needed. In this contribution, a mechanical system with 5 degrees of freedom modelling a generic synchronizer consisting of engaging sleeve, synchronizer ring and gearwheel are considered.Due to the design of the different components and their interactions the synchronizing process is described in terms of different steps or phases; presynchronization, main synchronization, blocker transition and engagement. The four main phases are further divided into sub-phases.To study the whole process in a unified manner, Constrained Lagrangian Formalism (CLF) turns out to be a suitable method in which the interactions between components (sleeve,synchronizer ring and gearwheel) are described by unilateral or/and bilateral constraints imposed on generalized coordinates of the system during different phases. Using CLF a mathematical model of a generic synchronizer is developed and represented by the system of differential-algebraic equations. Kinematics and kinetics of the generic synchronizer are modelled for each sub-phase. The sleeve is considered as a master and thegearwheel is considered as a slave. The statement of the dynamics problem for a generic synchronizer is given and the numerical algorithm is implemented in Matlab for solving the differential-algebraic equations resulting from CLF. The generic synchronizer computational model is adapted to available experimental setup and validated using obtained measurement data. Sensitivity of the synchronization time is studied varying the cone angle, coefficient of dry friction and sleeve force. Effect of driveline vibrations on synchronization performance isalso studied.
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