Download citation file:
A 1-DOF translational link, also called a linear joint or reciprocating joint, realizes a function of a prismatic kinematic pair and presents one of the basic units of different machines and robots. The link provides the 1-DOF translation by means of an actuator and constraints nominally preventing the relative movement along and about five DOFs. A triplet of linear stages performing the XYZ motions arranged in series presents a regular part of the 3-D Cartesian robots, coordinate measuring machines (CMM), milling machines, CNC milling and machining centers, etc. To provide high stiffness, accuracy and precision, and loading capacity, the linear guideways, also called linear motion bearings, are widely applied. In feed units of machine tools, the most widespread structure of the linear motion stage is a slider actuated by a motor-driven ball screw and moved along prismatic guideways of different forms (Fig. 9.1). Here, three types of prismatic guideways are shown: flat guideways, combined guideways (a set of flat- and V-form), and double V-form guideways.