Introduction

Abstract

This book is concerned with those aspects of the design of mechanical machines, and hence the components and parts from which they are made, that ensure reliability. But, because the words ‘design’ and ‘reliability’ can mean so many different things to different people, it is necessary to be quite clear at the outset exactly how those words will be used in this book. To start with, we shall exclude from our treatment all aspects of functional design. Thus it will be assumed that at least one prototype has demonstrated that it is possible to build a machine, or a component of a machine, that will do the job we require it to do to our satisfaction. We shall also exclude all aesthetic design, or styling, from the treatment, even though to many people this is what design is all about. This book will then be concerned with the design methodology that ensures that a number of items of the same product, i.e. made to the same design, will perform in the same way whenever operated in the same manner: that is, there shall be no, or in some case only an acceptable number of, adventitious malfunctions, breakdowns or failures. We shall thus be concerned with the inherent ability of the machine to continue functioning as specified. This may be thought of as a rough and ready definition of mechanical reliability.