Summary

Machine design is the process of creating systems that can convert energy into useful work. Engineers design both simple and complex machines for various purposes. A simple machine is a device that changes the direction or magnitude of a force, such as a ramp or a lever. A complex machine is a device that uses movement to perform work, such as a transmission or a robot arm. In this chapter, we will explore some principles and methods of machine design.

For the detailed design stage, one of the first tasks of machine design is to synthesize a machine that can perform a specific function under certain constraints. Synthesis means finding the best possible form and arrangement of the machine elements, such as linkages, gears, springs, etc., to achieve the desired output. For example, if we want to design a machine that can lift a heavy load, we need to consider what type of mechanism can provide enough force and displacement, and how to connect the components to form a stable structure.

The next task of machine design is to analyze the behavior and performance of the machine under various conditions. Analysis means finding the optimal way to control the machine, such as input power and speed, to achieve the required functionality without violating any other constraints, such as safety, reliability, efficiency, etc. For example, if we want to design a machine that can move parts in a manufacturing process from one area to another, we need to consider how to regulate the motion and speed of the machine, and how to avoid collisions and failures.

The first step in machine detail design is to identify the functions and constraints of the problem. For instance, we may need to specify the size and weight of the parts, the distance and direction of the movement, the time and accuracy required, the available space and resources, etc. The second step is to generate multiple possible solutions that can satisfy the functions and constraints. For instance, we may consider different types of mechanisms, such as linkages, gears, belts, chains, etc., that can provide the necessary movement and force. The third step is to evaluate and compare the solutions based on some criteria, such as cost, feasibility, simplicity, etc., and select the best one. Finally, we get to the main point of this chapter; to fully define and refine the solution by applying the techniques of synthesis and analysis. For instance, we may need to determine the dimensions and shapes of the machine elements, and the parameters and settings of the control system.

The final outcome of machine detail design is a detailed specification of a machine that can perform the desired work in an efficient and reliable manner.

In this chapter we will explore in detail the three most common types of machines used in mechanical systems, how to synthesize their form and perform analysis to ensure they achieve the desired function within constraints.