Machine
A machine is a tool that consists of one or more parts and uses energy to achieve a particular goal. A simple machine is a device that simply transforms the direction or magnitude of a force, but a large number of more complex machines exist. In general, a simple machine can be defined as one of the simplest mechanisms that provides mechanical advantage. Usually, the term refers to the six simple machines-lever, wheel, axle, pulley, inclined plane, wedge, and screw. These simple machines are considered to be the “building blocks” of more complicated machines.
A simple machine has an applied force that works against a load force. If there are no friction losses, the work done on the load is equal to the work done by the applied force. This allows an increase in the output force at the cost of a proportional decrease in the distance moved by the load. The ratio of the output force to the input force is the mechanical advantage of the machine.
Machines lose energy through friction, deformation, and wear, which is dissipated as heat. This means the power out of the machine is less than the power in. The ratio of power out to power in is the efficiency of the machine, and is a measure of the energy losses,
n = P OUT / P inÂ
Machines are assembled from standardized types of components. These elements consist of mechanisms that control movement in various ways such as gear trains, transistor switches, belt or chain drives, linkages, cam and follower systems, brakes and clutches, and structural components such as fasteners. Modern machines include sensors, actuators, and computer controllers.
Here are some examples of the machines:
- Â Lathe: It utilizes mechanical energy to cut the metals.
- Â Turbines: They produce mechanical energy.
- Compressors: They use mechanical energy to compress the air.
- Engines: They consume the fuel and produce mechanical energy.
Based on applications of the machines, they are classified into three main types, these are:
Machines generating mechanical energy:Â
The machines generating mechanical energy are also called prime movers. These machines convert energy like heat, electrical, etc into mechanical energy. An internal combustion engine is an example of this type of machine.