Worm gear

helical-toothedfor gear wheels

OTT worm gears are characterized by a clever design. The wheel rotates thanks to the worm, which is composed of two parts: a hollow worm and a shank worm. Both half-worms rotate the wheel in opposite directions. During the mounting stage, the operating clearance is adjusted according to the position of the worms on the wheel. For important accelerations, an "important" clearance will be chosen while for applications with few accelerations an almost nonexistent backlash will be preferred. There is also a possibility to set up the backlash by rotating or translating the worms when starting or reassembling. The worm's overlap is important due to the pressure angle: excellent contact ratio factor. (Constant speed, and elimination of faces during machining). Possibility of high driving torque thanks to the large number of teeths in contact. The backlash can be adjusted (if necessary) without resetting the whole table. Circularity and concentricity errors are suppressed thanks to a low pressure angle. We ourselves integrate OTT worm gears in our products, such as in our CN rotary tables which equip our boring machines, our different grinding machines, our control applications, our goniometers (tables used in fondamental research), and our 5-axis grinding machines.