What is the function of lathe screw and polished rod?

The polished rod is used as a guide and the screw rod is used as a servo drive. Both the polished rod and the screw rod of the lathe transmit torque to move the tool rest. The polished rod cannot guarantee the accurate transmission ratio from the structure. Therefore, it is generally used for turning excircles, end faces and inner holes. Generally, there is no need to turn the thread; The function of the design screw is that the spindle rotates once, the tool rest can move the corresponding distance accurately, and the pitch of the lathe can be ensured to be equal, so the screw is used to turn threads; Moreover, there is an interlocking effect between them in design, that is, the polished rod turns to the screw, and the screw turns to the polished rod. Prevent two people from damaging the equipment at the same time. Lead screw drive is used to process all kinds of threads, and polished rod drive is used to process all kinds of excircles, inner holes, end faces and steps. Lead screw and polished rod: used to connect the feed box and the slide box, and transmit the motion and power of the feed box to the slide box, so that the slide box can move vertically and linearly. The lead screw is specially designed for turning various threads. When turning other surfaces of the workpiece, only the polished rod is used instead of the lead screw. Students should distinguish the difference between polished rod and lead screw according to the content of sliding box. Slide box: it is the control box of lathe feed movement, and it is equipped with a mechanism to convert the rotary motion of polished rod and lead screw into the linear motion of tool rest. The polished rod drive realizes the longitudinal feed movement, transverse feed movement and rapid movement of the tool rest, and the tool rest is driven by the lead screw to make longitudinal linear movement, thus turning threads. The main components are: spindle box, exchange gear box, feed box, slide box, tool rest, tailstock, polished rod, lead screw, bed, bed foot and cooling device. 1797, the British mechanical inventor Maudslay created a modern lathe with a lead screw driving the tool rest. 1800 adopted gear exchange, which can change the feed speed and the pitch of the processed thread. 18 17, another Englishman Roberts adopted a four-stage pulley and rear wheel mechanism to change the spindle speed.