Definition
The subject Theory of Machines may be defined as that branch of Engineering-science, which deals with the study of relative motion between the various parts of a machine, and forces which act on them. The knowledge of this subject is very essential for an engineer in designing the various parts of a machine.
Note: A machine is a device which receives energy in some available form and utilizes it to do some particular type of work.
Sub-divisions of Theory of Machines
The Theory of Machines may be sub-divided into the following four branches:
1. Kinematics
It is that branch of Theory of Machines which deals with the relative motion between the various parts of the machines.
2. Dynamics
It is that branch of Theory of Machines which deals with the forces and their effects, while acting upon the machine parts in motion.
3. Kinetics
It is that branch of Theory of Machines which deals with the inertia forces which arise from the combined effect of the mass and motion of the machine parts.
4. Statics
It is that branch of Theory of Machines which deals with the forces and their effects while the machine parts are at rest. The mass of the parts is assumed to be negligible.