Singh, M., Singh, P., Kumar, K., and Rawla, V., "Development of Test Method to Validate Synchronizer Ring Design for Torsional Fluctuations in Manual Transmission," SAE Technical Paper 2016-28-0012, 2016, doi:10.4271/2016-28-0012.
Manual transmissions dominate the Indian market for their obvious benefit of low cost and higher mechanical efficiency resulting in higher fuel economy. Synchronizer system in manual transmission enables smoother and quieter gear shifting. Synchronizer ring is the key element which provides the necessary frictional torque to synchronize the speed of gear and sleeve for smooth shifting.During vehicle running, synchronizer rings are free to rattle inside the indexing clearance. High engine torsional excitation and low clutch dampening can result into increased fluctuation of the input shaft of transmission. High fluctuation or lower contact area of synchronizer ring can lead to damage on the index area. This damage may cause hard gear shifting and gear shift blockage in case of extreme damage.This paper presents the work done on understanding the effect of torsional fluctuations on synchronizer ring and development of test method for validation of synchronizer rings under this environment.