HERE WE ARE GOING TO STUDY ABOUT TYPES OF LATHE MACHINE AND ITS PRINCIPAL PARTS.
INTRODUCTION OF LATHE MACHINE
(LATHE MACHINE)
A lathe is one of the oldest and most important machine tool for every developed.it is widely used metal cutting machine tool.
It is Invented by Henry Maudslay in the year 1797.
what is Lathe machine??
Lathe is machine tool which removes undesired material from a rotating workpiece in the form of chip. The lathes are also used for facing , recessing , thread cutting and parting - off operations.
WHAT IS TURNING?
Turning is a machining process used to make cylindrical parts in which the cutting tool moves in a linear fashion while the workpiece rotates. Commonly performed with a lathe, turning reduce th diameter. a workpiece to a specified dimension and produces a smooth part finish.
PRINCIPLE OF TURNING:-
In lathe , work is held between two rigid and strong supports called centres or in a chuck or in a face plate . The chuck or face plate is mounted on the spindle of the lathe . The cutting tool held in a tool post and is fed against the rotating workpiece .
The tool can move parallel and perpendicular to the axis of rotating work piece .It can also move at an inclination with the axis to cut the desired material . The basic elements involved in metal removal process .
CLASSIFICATION OF LATHE MACHINES:-
Here important types of lathe machines are :-
- Speed lathe machine.
- Engine or center lathe.
- Bench lathe.
- Tool room lathe.
- Capstan and turret lathe.
- Automatic lathe.
- Special purpose lathe.
1.)Speed Lathe :-
Speed lathe is simplest among all types of lathes. It is driven by power and consists of a bed . a headstock , a tail stock and an adjustable slide for supporting the tool.
The tool is mounted on the adjustable slide and is fed into the work by hand only . Spindle speeds usually from 1200 to 3600 rp.m. can be obtained easily The speed lathe is used mainly for the following purposes:
- Wood working.
- Center Ing.
- Metal spinning.
- Polishing.
2.)Engine or Center Lathe:-
It is a general purpose lathe and is widely used in workshops. It is called engine lathe because in early times, power was used to obtain from the engines. Although , it practically resembles a speed lathe in most of its features , but its construction is relatively more robust.
In this,cutting tool it may be fed in both directions, longitudinal and cross , with reference to the fathe axis with the help of a carriage . The engine lathe , depending upon the power transmission , may be classified as follow :
- Geared head lathe ,
- Motor driven lathe ,
- Belt driven lathe.
3.)Bench Lathe:-
It is a small lathe with bed upto about 1.8 m long and swing upto about 30 cm and is commonly set on bench . In most cases , it is as complete as larger lathe , but smaller and lighter . It is used for small and precision work.
4.)Tool Room Lathe :
This lathe looks like a conventional engine lathe , but it is built more accurately. it has more speeds and feeds and is equipped with all the accessories and attachments , costs more and is mainly used for the manufacture of small tools , dies , gauges , fixtures and precision parts of all kinds. It may either be a pedestal or a bench type.
5.)Capstan and Turret Lathe :
Turret lathe is similar to standard lathe with op modification. In this , the tailstock has been replaced by a hexagonal head known as turret . This turre is capable of being rotated so that various tools mounted on this turret can be brought to the job a and when required Capstan lathe is similar to turret lathe . but it is light and used for lighter work and secondly, it hus got square head.
6.)Automatic Lathe :
It is a special purpose lathe whose movements are controlle automatically. In this , the operator has to load and unload the job and rest of the work performed by the lathe itself . It is very widely used for the production of bolts etc.
7.)Special Purpose Lathe :-
Special purpose lathes are designed to perform the specific operations, which cannot be performed efficiently by the standard lathes. Some special purpose lates are as follow :
i ) Gap Bed Lathe : It has a special sliding bed making it possible to accomodate the large diameter work.
ii)Wheel Lathe : It is used for duplicating the shape of certain object.
iii) Screw Cutting Lathe : It is used for the mass production of the screwed parts.
(iv) Duplication Lathe: It is used for duplicating the shape of a certain object.
PRINCIPAL PARTS OF A LATHE MACHINE AND THEIR FUNCTIONS:-
The main parts of a center lath is shown in fig. The principal parts of lathe are as follow
- Bed,
- Head stock,
- Tailstock,
- Carriage,
- Feed mechanism,
1.)Bed :-
The bed is the base or foundation of the lathe . It is a heavy and rigid casting made in one piece to resist deflection and vibrations . It holds or supports all other parts i.e. head stock , tailstock , carriage etc.
2.)Headstock:-
The headstock assembly is permanently fastened to the left hand end of the lathe . It serves to support the spindle and driving arrangements . The spindle revolves in bearings , one at each end of the headstock . The spindle is rotated by a combination of gears and cone pulleys or by gears alone.
3.)Tailstock :-
It is located on the inner ways of lathe bed at the right hand end of the bed . It has the following main uses :
( i ) I helps in performing taper turning operation .
( ii ) It holds a tool for performing operations such as reaming drilling , tapping etc.
( iii ) It supports the other end of the work when it is being machined between centres.
4.)Carriage :-
It is placed between the headstock and the tailstock.It controls and supports the cutting tool . It is movable on the bed ways and its purpose is to hold the cutting tool and to impart to it either longitudinal or cross feed.
5.) Feed Mechanism :-
The movement of tool relative to work is termed as feed . A lah tool may have three types of ſeeds : Longitudinal , cross and angular .
TYPES OF LATHE MACHINE AND ITS PRINCIPAL PARTS.
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