Parts of lathe

Different parts of a lathe are:

Bed

Headstock

Carriage Unit

Tailstock

Feed Mechanism

Screw cutting mechanism

Bed

It is the base of the lathe which carries all the parts over it. There is two guide ways on the top of the bed-inner ways and outer ways. The outer ways guide the carriage unit and inner ways guide tail stock Bed is made up with material of high compressive strength, wear resistance and toughness like Cast iron or cast steel.

Headstock

The headstock is the hollow casting which accommodates the spindle assembly and its variable speed driving mechanisms.

It is secured permanently on the left end of the lathe bed.

The driving mechanism may be cone pulley drive with back gear or all gear drive in modern lathes. The speed can be varied by shifting hand levers in front of the headstock.

Carriage Unit

The carriage of the lathe has several parts that serve to support, move and control the cutting tool.

 

This unit consist of the following parts:

Saddle

It is the part of the carriage which slide over the lathe bed and provide longitudinal feed to the tool.

Cross Slide

It slide on the guide ways provided on the top of the saddle and provide cross feed to the tool.

Compound Rest

It is mounted over the cross slide and can be tilted at an angle and the top slide of it can be moved to provide angular feed to the tool.

Tool post

Tool post is mounted over the top slide and clamps the tool rigidly by using bolts.

Apron

It is the front panel of the carriage unit which accommodate the driving mechanisms to transmit the rotary movement of the feed shaft and lead screw to the longitudinal and cross feed movements.

Tailstock

Tailstock is mounted over the bed on its right end which can be moved along the bed and locked at any position.

The two main functions of tailstock are:

1. To support the other end of the long work pieces when it is turned between centres.

2. To hold the tool for performing operation like drilling, reaming and tapping.

 

Feed mechanism

The feed mechanism of the lathe has different units through 

which motion is transmitted from the headstock spindle to the carriage

Following are the units:

End bed gearing

Feed gear box

Feed shaft

Apron

 

Thread cutting mechanism

For thread cutting in lathe, the rotation of the spindle is transmitted to the carriage through end bed gearing and lead screw. The ratio of spindle rotation to the lead screw rotation can be changed by changing end bed gears either manually or by shifting levers to cut various pitches.