In this content, you can learn about the parts of lathe machine and it's working principle in the production process.


Parts of Lathe machine


Following are the integral parts of a lathe:-

(1) Bed


(2) Headstock


(3) Tailstock


(4) Carriage


(5) Feed Mechanism


Parts of Lathe machine and it's function are as following:-


(1) Bed:-


The bed of lathe is supported on broad box- section columns on which the different fixed and operating parts of lathe are mounted. Lathe beds are generally rigid casting of grey cast iron, nodular cast iron or high strength, wear resistance cast iron. Cast in single piece. 


           However in case of extremely large machines the bed may be in two or more pieces. The bed consists of two heavy metal sliders running lengthwise, with ways provide bearing and sliding surface for the carriage and the inner ways for the tailstock.


               Lathe bed is made of high grade special cast iron having high vibration damping qualities. The other advantages of using cast iron in lathe bed are its better compressive strength, its cast ability and machinability.


(2) Headstock:-


The headstock assembly is permanently fastened to the left hand end of the lathes and supports the main spindle in the bearings and aligns it properly. It houses transmission mechanism with speed changing levers for obtaining different speeds. Cone pulley or gears or combination of both could be used to change speed of Spindle. 


    Different types of work holding devices like; Chuck, Face-Plate , Collet chuck, Lathe dog can be mounted to headstock spindle. The steel spindle is a hollow cylindrical shaft through which long cylindrical jobs can pass and the hole through the spindle also makes it possible to use a knockout bar to remove such tools.


 The tapper spindle hole accommodates a tapper sleeve which holds the live centre.This centre is called live centre because it rotates with the workpiece and receives power directly from motor through transmission mechanism.


(3) Tailstock:-


Tailstock is situated on the right hand end of the bed; opposite the headstock on the ways of bed. Tailstock is movable casting which serves two purpose, (a) Supports the other end of the work being machined, and (b) Holds a tool for operations like drilling, reaming, tapping etc. 


     Tailstock can be moved along the bed and clamped to the bed at any desired location. Tailstock has two main parts . The lower part rests directly on the bed ways and the upper parts rests on the lower part. The two parts are held together by means of adjusting screw.
           

    The body of the tailstock has a bore for the hollow cylindrical sliding member known as a quill. This quill is operated by the Tailstock handwheel. The quill has a tapper hole into which the dead centre is fitted. Drills, reames, taps, and other end cutting tools are held and fed to the workpiece by the quill.


(4) Carriage:-


          The carriage is located between the headstock and tailstock. It is fitted on the bed and slides along the bed guideways and can be locked on the bed at any described position by tightening the carriage lock screw. 


   The lathe carriage supports, guides and feeds the tool against the job during the operation on the lathe carriage consists of the following main parts:-


(a) Saddle:-


       Saddle slides along the bed ways and supports the cross-slide compound rest and tool post.


(b) Cross slide:-


The cross slide is mounted on the saddle. It provides cutting tool motion which is perpendicular to the centre line of the lathe itself. It can either be operated by hand, by means of cross feed screw or by power feed through the apron mechanism.


(c) Compound Rest:-


Compound rest supports the tool post and cutting tool in its various positions. It is mounted on cross slide and has a graduated circular base on which it can be swivelled around a vertical axis. Like the cross slide the compound rest is also provided with micrometre collars for accurate adjustment when turning workpieces to close measurements and cutting screw threads.


(d) Tool Post:-


          Tool post is the top most part of the carriage and tool or tool holder is firmly held in it. Tool post gets its movement by the movement of the saddle, cross slide and top slide. Three types of Tool Posts are commonly used.


          
                    Ring & Rocker tool post, quick change tool post and square head tool post.


(e) Apron:-


        Apron is the hanging part in front of carriage. It contains the gears, clutches, and levers for operating the carriage by hand and power feeds. It also carries the split half nut. The split half nut in conjunction with the lead screw, moves the whole carriage in Thread cutting operations.


(5) Feed Mechanism:-


Feed mechanism provides various feeds, longitudinal cross and angular, to the cutting tool. Feed mechanism consists of feed reverse lever, timber reversing mechanism, change gears, feed gear box, quick change gears box, lead screw, feed rod, apron mechanism and half nut mechanism.


Conclusion:-


You have learnt about parts of lathe machine and it's working principle in the production process.