Engineering Acoustics

11Noise and Vibration Control of Machines

11.1 Introduction

Many different machine components are used in appliances, vehicles, aircraft, and industry. Some machine components including bearings, gears, fans, burners, cutters, and valves are used in machines built from several of these components such as pumps, compressors, electric motors, and internal combustion (IC) engines. It is impossible to discuss every type of machine and machine component here; so, the discussion is mainly concentrated on common machine components and complete machines. These machine components and machines do work, transfer energy, or convert one form of energy into another. In these processes some undesirable vibration and acoustical energy or noise is produced as an unwanted by‐product. It is the purpose of this chapter to review briefly the functioning of these machine components and machines, noise and vibration generation mechanisms, and methods of control. Several other books, book chapters, and articles also discuss machinery noise mechanisms and noise and vibration sources in more detail than is possible here [1–15].

11.2 Machine Element Noise and Vibration Sources and Control

11.2.1 Gears

Gears are used in a number of applications where mechanical power is transmitted. Gears can emit annoying and harmful noise levels when a fraction of the transmitted power is converted to noise [16]. Most modern gear teeth have an involute profile, although some have circular‐arc profiles [1, 2]. Figure ...