Analysis and Design of Machine Elements

1 An Overview of Machine Design

1.1 Introduction

1.1.1 Machines and Machine Elements

A machine is a device that employs power to accomplish a desired function to benefit humankind. It is generally composed of a power source to provide power and movement, and an executive device to fulfil intended function. In between is a transmission system and controller. Power sources can be prime movers, that is, a machine utilizes a natural source of energy to produce power, like an internal combustion engine; or a secondary mover, like an electric motor, which receives energy directly or indirectly from a generator driven by a prime mover [1]. Take a car as an example; power sources, either engines in motor vehicles or batteries in electrical vehicles, provide power to executive devices; for example, wheels, through a transmission system (including couplings, clutches, shafts, powertrain etc.). The control system, that is, steering systems and brakes, control car movement. Lights, meters and windscreen wipers are accessories that facilitate a car running properly.

Machines involve a vast variety of mechanical products in various fields of manufacturing, transportation, aerospace, construction, agricultural, energy and many others. ‘Products’ covers industrial robots, machine tools and automated assembly systems in manufacturing systems; automobiles, trains, ships and aircraft in transportation vehicles; mobile cranes, dump trucks and concrete mixers in construction equipment. ...