Design And Experimental Study On Improvements Of Clutch Disc Assembly Pre-Damping Hysteresis

The main function of clutch is to cut off and get the power transmission of the transmission system; to limit the maximum torque of the drive system and prevent transmission system of the parts damage from overloading; to effectively reduce the vibration and noise of the transmission system. In the process of clutch slipping, the damping characteristics of the disc assembly determines if the growth of rotation speed is smooth and comfortable, and is whether to reduce engine noise and vibration,to affect the car started or shifting comfort. Therefore, the design of disc assembly is becoming the key elements in the matching process. Hysteresis of disc assembly is the difference between the torque of proceeding and reverse on the set point of torsion curve. It is a key characteristic of disc assembly.During the DST190 LK testing appears a failure mode called idle noise. The pre-damping hysteresis value is detected not qualified.After assembly dismantling, it had been found there are three main factors about the pre-damping hysteresis of driven disc assembly: pre-damping hysteresis value is too low, the attenuation of hysteresis is too large, the same batch of product pre-damping hysteresis value was discrete state and poor consistency.In order to improve pre-damping hysteresis of DST190 LK driven disc assembly,the following three aspects of the work were completed, including the verification and improvement of key parts of the pre-damping hysteresis, including the pre-damping system optimization design, before and after the improvement of the driven disc assembly pre-damping test and the NVH evaluation.It is taken the definition of pre-damping hysteresis of driven disc assembly as a start; proceed from multiple aspects of design, technology and materials. Check the modified the pre vibration damping space, disc springs, the experiment selected suitable friction coefficient and the intensity of friction washer. By optimizing the dimension chain and designing, parts process improvement, improve parts dimension consistency, improved dish spring load interval value curve slope is small, load valuerate of change is small, and there is no decay any more. The dish washer, driven disc,damping disc parts manufacturing precision were improved by improving the process and equipments of stamping and heat treatment. By optimizing the damping friction washer material, it is enhanced the friction coefficient, so as to improve the pre-damping hysteresis..It is found that significant improvement of the pre-damping hysteresis after assembling the driven disc assembly with the improved parts. The comparison results show that the improved pre-damping hysteresis is not only up to 100%, but also has improved significantly.The results of the NVH test show that, both of the subjective and objective evaluations, the improved parts are significantly better than before.The improvement of the pre-damping hysteresis has played an effective role in avoiding the idle noise of the car that DST190 LK assembled. And also the best value of DST190 LK ‘s pre-damping hysteresis is defined.