Screw Gears

Worm gears transfer rotary motion and power between non-parallel or non-intersecting shafts. They're used to reduce speeds or increase torque in mechanical applications that operate in confined spaces, such as power steering, machine tools, elevators, and chain blocks. Worm gears are a two-part mechanism that consists of a rod-shaped gear with spiral threading called a worm and a disc-shaped gear with projecting teeth named a wheel. The worm drives the wheel with a rolling and sliding action that creates minimal vibration and low noise output. However, their meshing motion creates friction, so they're typically paired in different materials to minimize heat and wear.