lecture slides

1. Machine Tool Drives
15/12/2022
 Machine Tool – Definition,
 Classification of Machine Tools
 Working and Auxiliary Motion & Parameters
 Calculation of Machining Time
 The Design of Machine Tool
 Machine Tool Drives

2. Machine Tool – Definition
15/12/2022
 Machine Tools produce desired geometrical surfaces on solid
bodies (preformed blanks) and for that they are basically
comprised of:
 Devices for firmly holding the tool and work
 Drives for providing power and motions to the tool and
work
 Kinematic system to transmit motion and power from the
sources to the tool work
 Automation and control systems
 Structural body to support and accommodate those
systems with sufficient strength and rigidity.
 For material removal by machining, the work and the tool
need relative movements and those motions and required
power are derived from the power source(s) and transmitted
through the kinematic system(s) comprised of a number and
type of mechanisms.

3. Machine Tool – Definition
15/12/2022
 To obtain a machined part by a machine tool, coordinated motions
must be imparted to its working members. These motions are
I. Primary (cutting and feed) movements, which removes the
chips from the WP
II. Auxiliary motions that are required to prepare for machining
and ensure the successive machining of several surfaces of one
WP or a similar surface of different WPs.
 Principal motions may be either rotating or straight reciprocating.
In some machine tools, this motion is a combination of rotating and
reciprocating motions.
 Feed movement may be continuous (lathes, milling machine,
drilling machine) or intermittent (shapers, planers). As shown in
Figure1., stepped motions are obtained using belting or gearing.
Stepless speeds are achieved by mechanical, hydraulic, and electrical
methods.

4. Mechanical Transmission and its Elements
15/12/2022
Fig. 4.1 Generation of flat surfaces by Generatrix and Directrix.
As shown in Figure
2.1, stepped motions
are obtained using
belting or gearing.
Stepless speeds are
achieved by
mechanical,
hydraulic, and
electrical methods.