Screw Mechanism Basics
Screw mechanisms consist of two main parts, a rod formed or cut with one or more helical threads, and a nut that engages those threads. Screw mechanisms can translate rotary motion into linear motion or, more rarely, linear into rotary. The four different setups shown in Figure 20.1 result from driving either the screw or the nut, and whether the drive is rotational or linear. In addition to the screw and nut, mounting blocks which are designed to support the screw and allow it to spin freely are available. Screw mechanisms are available either as individual parts or as full assemblies which usually consist of one screw, one nut and two mounting blocks. There are two main categories of screw mechanisms, ...