TABLE OF CONTENTS We are now ready for a study of the dynamics of machines and systems. Such a study is usually simplified by starting with the statics of such systems. In our studies of kinematic analysis we limited ourselves to consideration of the geometry of the motions and of the relationships between displacement and time. The forces required to produce those motions or the motion that would result from the application of a given set of forces were not considered.
In the design of a machine, consideration of only those effects that are described by units of length and time is a tremendous simplification. It frees the mind of the complicating influence of many other factors that ultimately enter into the problem, and it permits our attention to be focused on the primary goal, that of designing a mechanism to obtain a desired motion. That was the problem of kinematics, covered in the previous chapters of this book.
The fundamental units in kinematic analysis are length and time; in dynamic analysis they are length, time, and force.
Forces are transmitted between machine members through mating surfaces that is, from a gear to a shaft or from one gear through meshing teeth to another gear, from a connecting rod through a bearing to a lever, from a V-belt to a pulley, from a cam to a follower, or from a brake drum to a brake shoe. It is necessary to know the magnitudes of these forces...
