rack

grabcad

Pinion and rack The term "rack and pinion" refers to a mechanism in which a rotary motion is converted into linear motion. The pinion, a small gear, meshes with a larger, flat-toothed bar called the rack. As the pinion rotates, the teeth of the rack cause it to move back and forth in a straight line. This system is commonly used in steering systems, mechanical actuators, and other applications requiring precise linear movement.