A rack and pinion gate consists of a gate frame, blade, rack(s), pinion gear(s), pinion shaft, shaft bearings and a manual or powered shaft drive.
A rack and pinion is a type of linear actuator that comprises a circular gear (the pinion) engaging a linear gear (the rack). Together, they convert rotational motion into linear motion. Rotating the pinion causes the rack to be driven in a line. Conversely, moving the rack linearly will cause the pinion to rotate.