Head stock is a type of box permanently on the inner ways at the left hand. End of the lathe bed and it provides rotating the work at multiple speeds. Head stock is comprise the essentially a hollow spindle and mechanism for driving, altering the spindle speed. All the parts are housed within the head stock assembly.
Head stocks consisting of main parts are.
- All gear drive
- Belt driven head stock
- Speed changing
Head stock spindle is usually of a large diameter to resists bending and it should be aligned with the lathe machine axis and accurately machined for producing true of work surface.
A hole is extends through the spindle so that a long bar may be passed through the bore. The front end of the hole is appeared for holding canters and other tools having a standard taper shank.
A taper sleeve fits into the taper hole and a live center which supports the work and revolves with the work fits into the sleeve that acts as a bush.
The spindle revolves on two large bearings housed on the head stock casting. The clearance between the spindle and the bearing should be preventing vibrations are minimum. The bearing may be bush, roller or ball type depending on whether it is a heavy duty, high speed or precision machine.
The thrust bearings are provided to take up the end load owing to the feeding action of the tool. Here the provision is made for expansion of the spindle when it gets heated under high speed metal machining.