Research On Performance Of Vibration Reduction Of Transmission System With Dual Mass Flywheel

The torsional vibration of the automobile power transmission system is an important factor that affects the NVH performance of the vehicle.Due to the structural limitations of the traditional clutch itself,the torsional stiffness of the vibration damping system is large,and the vibration isolation rate is basically about 20% to 30% under the premise of meeting the torque transmission capacity.NVH problems such as idle noise,accelerated resonance and accelerated roar are prone to occur.The dual mass flywheel(DMF)is used,and the twisting angle can be about ±70 °.As a result,the torsional stiffness is greatly reduced,the vibration isolation rate can reach more than 70%,and the riding comfort is greatly improved.This article will study the performance of vibration reduction of dual-mass flywheel that matches a three-cylinder model.The main work of the article is as follows:(1)The basic structure,working principle and performance characteristics of common dual-mass flywheels are described.This article comparatively analyzes the research status of domestic and foreign related literatures related to this subject,and puts forward the shortcomings of the current research.The research goal and research content of this subject are determined.(2)The design method of elastic element and damping element of dual-mass flywheel is studied.And the finite element analysis method is used to analyze the strength of the key parts of the dual-mass flywheel-the drive disc,the primary flywheel,the ring gear,the arc spring assembly and the secondary flywheel.Virtual simulation technology can shorten the development cycle of new products and reduce development costs.(3)The torsional characteristics model of dual-mass flywheel is established.Study the relationship between hysteretic nonlinear torsion curve,friction factor and speed.A torsion characteristic test of dual-mass flywheel was carried out to verify the accuracy of the model established in this article.(4)A five-degree-of-freedom dynamic model of the automobile transmission system is established,and the fourth-order Runge-Kutta method is used to numerically solve the model.The speed fluctuations of the primary and secondary flywheels of the dual-mass flywheel are calculated and verified by experiments.Further,the weighted vibration attenuation rate of the dual-mass flywheel is used to optimize the objective function,and the sequential quadratic programming(SQP algorithm)is used to compare the rotational inertia ratio of the primary and secondary flywheels of the dual-mass flywheel.Six parameters including stiffness,dry friction damping,maximum torsion angle of first stiffness and preload torque are optimized for design.The vibration damping performance of the dual mass flywheel has been greatly improved.