Investigation on the fluid coupling of a gearless two wheeler

Abstract

In the present scenario, there is an improved attention towards the development of Gear-less two-wheeler mopeds [scooters] which have automatic-transmittal systems, using the centrifugal type clinch systems. These centrifugal type of clinch systems have high wear and tear(worn out) and hence the present research work is taken up to replace the said centrifugal clinch system with a fluid coupling which may be more effective in the wear-free transmittal and it will provide a smooth and a controlled acceleration with effective damping of shocks, effective dampening of the load fluctuations and also torsional vibrations. The attention is therefore laid on developing a highly-efficient type modified fluid coupling. This fluid coupling would then draw the mechanical power from the main source, namely the I.C. engine and then transmits it to the rear wheels via an automatic gear box. The fluid coupling has an advantage over the mechanical type coupling in following areas. (1) Efficient dampening of shocks, load fluctuations and torsional vibrations. (2) Smooth, controlled ,seamless acceleration in transmittal of the vehicle. The hurdle lies in developing an efficient modified fluid coupling which would transfer the mechanical power with minimum transmittal losses in the case of Two-Wheeler automobiles especially the Gear-less Scooters. The objective of this research work is to emphasize the study conducted on the power efficiency of a basic-fluid coupling firstly without vanes and then a modified-fluid coupling [with vanes]. This is continued by fabricating and then experimentally testing a fluid coupling design based on the data elicited suggestions from the computational study. The computational study was helpful in making an preliminary estimate of the efficiency of a basic modified-fluid coupling design without vanes and consequently in making recommendations on scope for further design improvements i.e. using vanes on the two discs. Based on the suggestions from the computational study a conventional fluid coupling w