Mechanics of Machining

Introduction

Mechanics of machining is the most stable and reliable method of manufacturing and fabricating holistic and precise metal parts. This process has been around for several decades. The manufacturing includes a wide range of products. Fabrication of single products uses alloys and metals like brass, steel, bronze, and copper. Apart from the fabrication of products, it is used to make standard products, too. In precision engineering, the manufacturing processes include milling and electro-erosive processes through spark erosion and wire. Mostly, complex pieces of machinery are used. These cannot sustain thermal exposure for much longer. For such situations, electrochemical machining is used.

Mechanics of machining is important for mechanical engineers and need to bestow lots of time behind it. The working needs to be understood to get a clear grasp of the process. Mechanics of machining has several sub-topics under it as it is a vast topic. Designing, manufacturing, analyzing, and maintaining mechanical systems are a part of the system. Mechanics of machining is one of the broadest and oldest branches of engineering.

Theory of Machines

The branch of engineering science that deals in relative motion study between several elements of a machine and the forces that act upon them are known as the theory of machines. A device that can receive energy in any form it is available and uses that energy to do some work is termed as a machine. The power that a machine transmits is controlled in nature. Several kinetically related links from a machine. The structure of a machine is made in such a manner that when one part of the machine moves, all the other parts follow that motion. The motion depends on the connection between the fragments of a machine.

The kinetically related links can be rigid-pneumonic, rigid-hydraulic, or rigid. The power that is put into the machine can be nuclear, mechanical, chemical, or hydraulic. Output power is found in thermal, hydraulic, electrical, or mechanical forms. The first person to discover the theory of machines was Galileo Galilei. He was an Italian scientist and the first one to discover the fact that machines are not a way of creating energy, but simply transforming it.

There are several examples of machines. The most common ones are heat engines, which transform heat energy into mechanical energy; electric motor, which transforms electrical energy into mechanical energy; and a pump, which receives electric power and transforms it into hydraulic power.

Classification of machines

Machines can be classified into three groups. The groups are as follows:

1. The first category includes types of machinery that are used for generating mechanical energy. These types of machines transform all types of energy into mechanical energy. Examples of these types of machinery include steam engines, gas turbines, steam turbines, water turbines, etc.
2. The second category includes machines that are used for transforming mechanical energy into other forms of energy. It is also referred to as converting machines. The second category is the complete opposite of the first one. Examples of the second category are hydraulic pumps, electric generators, etc.
3. The third category includes types of machinery that use mechanical energy into performing handy work. Example – Lathe.

The transformation and modification of the energy that the machine requires to work, uses several parts. The parts are selected in such a way that the machine will work in the manner that it will be subjected to.

Machine and mechanism – Differentiation

In words of kinematics, the means of constraining, transmitting, or controlling relative movement, is known as the mechanism. The main structure of the mechanism is the connection of rigid bodies with the help of joints. In simpler words, a mechanism can be referred to as resistant bodies being connected and shaped in such a way that it moves with relative motion. The motion is definite, and the motions are respectful of each other. 

A combination of resistant or rigid bodies which are formed and connected in certain ways that move in relative motion to the other parts is termed as machines. A machine also transmits force. In general, a machine has two functions. The first function is a transmission of definitive relative motion, and the second function is to transmit force. Geometric bodies which are combined to form a part of the machine or a machine are known as the mechanism.

Slider crank mechanism and IC engine are examples of mechanism and machine, respectively. The slider-crank mechanism is used to convert the circular motion of the crank into the sliding motion of the slider. In the case of the IC engine, the above mechanism is used in converting the mechanical energy into the required torque in the crankshaft. 

Conclusion

Mechanics of machining forms an integral part of mechanical engineering. It has several branches and each of them is quite complex. The theory of machines and mechanisms forms an important part of that topic. Most of the information is covered in the above article, and the FAQ section has a few probable questions and answers.