The Characteristic Study And Structure Design Of A New Type Of Dual Mass Flywheel

The automobile as one of the great invention has been developed for hundred years. With the industry's development, people have the remarkable higher and higher requirement for cars'comfort quality. How to realize the noise reduction and absorption becomes a key problem.The power train of automobile is the main source of the noise and vibration especially for torsional vibration.People pay more attention on it and developed lots of effectual methods.Dual-mass flywheel (DMF) was one of the innovations for reducing torsional vibration in recent years .It could reduce the vibration of the power-train very well. At present, almost all kinds of the diesel vehicle in the European market have made use of dual mass flywheel. In our country, we also try to develop it, although we have's made it mass production, we still get some progress.DMF has two advantage for the field of damping——rectify frequency and reduce rigidity. On the one hand, it can change the intrinsic frequencies of power train via choosing suitable mass,rigidity,damper. It can reduce the low natural frequencies which have great influence to the chassis to get the aim to reduce the resonance speed of the car. On the other hand, it can obviously reduce the rigidity between two flywheels so as to minish the influence of the engine torsional fluctuation.There si still disadvantage one of the DMF. The inertia increased of the second flywheel of DMF can benefits for reducing the torsional vibration in drive model, but when we consider the start behavior, the effect is opposite.The author thinks the Innovation is the power for technology development .DMF is the innovation on traditional CTD. So if we didn't try to innovate ,we will always behind others . this paper get some study on the characteristic of DMF and want to design a new type of DMF intrepidly whose inertia of the second flywheel can be changed following the speed of the vehicle .First , this paper investigated the power train of a medium-size truck, and built two 17-freedom-degree vibration models, one uses Clutch Torsional Damper, and the other uses Dual-Mass Flywheel, each model just considered the engine torsional vibration. Then established the vibration equation based on the second Newtonian law and calculated the equation use a program built in the software MATLAB according to the analyses of the mode. The result confirms that DMF could decrease cases of resonant vibration and it can efficiently improve the torsional vibration of the truck.In the interface of virtual prototype soft ADAMSA ,we build the virtual prototype of the model .Then analysis the torsional vibration in the both drive mode and start mode with different inertia of the second flywheel. We get the conclusion that big inertia of the second flywheel is good for the high speed drive mode but it do badly to the start behavior. Base on this theory, we build the concept prototype of the new type of DMF.If you want to design the structure of the DMF you need to optimized the main parameters——mass,rigidity,damp are the three key parameters of a DMF. Before we start to design the structure we have to optimize it. We use virtual prototype technology to do the optimization based on the power train model built before. We use the amplitude of the second flywheel's angular speed as the optimized function and use Generalized Reduced Gradient method as optimized method to do the optimize. Then we get the optimized value of the three main parameters.After we got the main parameters we get to the design of the structure. In the progress of the DMF design, the torsional rigidity and the Slippery piece are the key points. This paper compares the different kinds of spring DMF, at last chose the arc spring DMF as the basic part. The arc spring use the combination of big and small arc spring. The author follows several papers build the formula and calculates it. The centrifugal force of the slippery piece is provided by straight spring. In the structure several main forced parts need to be analysis for strength, so we do the check using FAE. Finally drew the 3-D Graphic model.The main content of this paper is completed in the simulation of computer. The designed DMF is still at the stage of drawings. The theory we discussed is a new explore. The correctness can't be proved by tests. So the author hopes the comers can go on doing it. If the paper can do some contribution to the idea of DMF, author will be very happy.