Lathe is an important, varied class of metalcutting machine tools. Among the turning operations that can be performed on lathes are machining of conical, cylindrical and irregular surfaces, facing ends and drilling of holes and other operations can be performed on lathes by using special jigs.
Major components of lathe machines tools are base, bed and fixed headstock. Base with a trough is used for the collection of cutting fluid and chips. Beds with guides are used carriage and tailstock and fixed headstock comprises of a spindle and gearbox. There are also various other components like movable tailstock, feedbox, support, apron and rotating unit.
During cutting operation, the workpiece is held in a chuck or in conical pins, is rotted by the main drive. Provision is comprised for stepped or infinitely different speed control of the spindle to attain the necessary cutting rate. The translator motion of the cutting tool is developed the kinematic chain of the feed motion that first unit is the spindle and the last unit is a rack and gear drive for turning or the kinematic pair of the feed screw.
The spindle unit is durable and prevents vibration. The spindle often rests on rolling contact bearings. Hydrostatic bearings are used in accuracy lathes. A faceplate can be connected to the front end of the spindle. Tailstock is used for materials in conical pins and for fastening the tools in drills, countersink reaming as well as reaming.
The main drive of a lathe includes a single-speed or multi-speed asynchronous electric motor and a multistep gearbox or mechanical variable speed drive. DC motors and gearboxes are often used in heavy lathes. Additional drives like hydraulic drives are also used on requirement.
The need of automation of production has resulted into the development of automated lathes that introduce various special characteristics. Besides to the traditional specification, an order is followed in which the bed has inclined guides, to remove the chips and safety of the work place. The cutting area is enclosed by a hood. Programmed operations include shifting, lengthwise and transverse movement of the carriage with variable control of the feed, quick traverse of carriage, rotation of the turret, beginning, stopping, reversal of main drive, and automatic tool switching.
Universal laths are widely used for unit and lot development. They are comprised of hydraulic and electric reproducing connection and fast clamping automatic chuck for use in lot development.