Transmission error and wear measurements of involute helicoidal worm gears

Worm gear transmission error (TE) is an important transmission parameter when precision is required. Modem cutting methods in conjunction with modern software allows a designer to achieve very high accuracy of worm gear pair at early meshing stages. However, wear which is always present in soft-hard worm transmissions continuously changes the shape of contacting surfaces and hence changes gear performance. A novel manual coordinate measurement system has been developed for an experimental worm gear wear study. It can be used to measure worm wheel tooth wear and pitch errors in-situ, and its repeatability is better than +/-3 mum. In contrast to other commonly used methods of wear measurements (e.g. via backlash), the equipment can measure wear distribution across the wheel teeth rather than wear averaged value, which opens wider possibilities for worm gear wear research