Cylindrical Worm Wheel

One distinguishes two types of cylindrical worm and wormwheel：
A set “worm and helical gear”
A set “worm and wormwheel”
The first set is a special case of the ‘helical gears for crossed shafts’ where the pinion for only counts l, 2, 3 (or a small number of) teeth and is characterised by a large helix angle of the tooth.