engleski

The Efect of the Random Tooth Worm Gear geometry on Efficiency

This work presents a theoretical approach to calculation of the maximum load and the power loss in worm gears based on Hertz's theory of contact pressures. As a result an expression for the efficiency of toothing is obtained. After that a computer program for determining the contact lines in the gear engagement field, required for the calculation of toothing efficiency of the worm gears is developed. This program enables calculations of non-dimensional quantities which depend on the toothing geometry only (and not on the operating conditions), and the parameters necessary for the calculation of the friction factor: the slip velocity, the sliding-rolling ratio, and the radius of curvature. Based on the calculated quantities, which depend on the geometry and on the friction factor, which is calculated by employing an expression based on experiments, the toothing efficiency is obtained. The efficiency based on theoretical considerations is compared with experimental results obtained on a test bench with real worm gears for two rotational speed as at the inlet and for different loading conditions at the outlet. In doing that two kinds of oil, mineral and synthetic are employed.

worm gears; contact lines; sliding-rolling ratio; efficienci

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