Motion Solutions

Screw Driven

Screw Driven

Screw-type actuators convert rotary motion to linear motion using a nut on a rotating screw. Turning the screw with a rotary motor causes the nut, and whatever is attached to it, to move relative to the screw. Screw-type actuators are commonly used in positioning systems for a broad range of applications including packaging, converting, medical, laboratory instrumentation, semiconductor, and test equipment.

Screw-driven precision stages can deliver accuracies as high as 2 µm. Although lead screws tend to be limited in length to a meter or so, with large enough screw diameter, they can handle loads of better than a thousand pounds. The screw thread pitch introduces a significant mechanical advantage, which can eliminate the need for gearboxes in many applications.

Each screw has a critical speed that is a function of diameter, thread pitch, etc. Past this critical speed, the screw bows outward as it rotates in what is known as screw whip. Paired with the right application, though, screw-type actuators can be effective and budget friendly.