Design, Analysis and Experimental Study of Worm and Worm Gear Pair for Plug Valve Application

Abstract

The present work deals with the design procedure, load carrying capacity, mathematical modelling,
analysis of worm and worm gear for plug valve application. The plug valves are used in various fluid
services applications. It performs well in slurry applications. It is also used in air, gaseous services
and oil piping systems and a like applications. In plug valve the main and important function of the
worm gear drive is to reliably transmit torque and rotary motion. This paper throws light on
addressing these issues by performing experimental work for finding out efficiency of worm gear for
plug valve application. The contact stresses of gear tooth are regarded as contributor for the failure
of the gear. Thus, the analysis for these stresses has become essential for minimizing the chances of
failure. The mathematical model was developed to determine the surface stresses acting on the gear
tooth. The testing performance of the worm and worm wheel gear pair is depending upon the torque
carrying capacity of the gear pair at the rated speed. The torque testing set up is designed for a worm
gear pair with dynamometer. Rigorous trials were conducted by the use of testing set up and readings
were used to plot a graph of torque vs speed, which gives the performance of the worm and worm
wheel gear pair at the rated speed. The obtained results provide significant information for predicting
the static and dynamic performance of worm gear pair. It is observed that there is improvement in
efficiency for modified worm gear pair which is used in plug valve application. As the output torque
increases efficiency also seen to be increasing.