TABLE OF CONTENTS There are two approaches to dynamic analysis, commonly called the forward and the inverse dynamics problems. The forward problem assumes that the forces acting on the system are known and solves for the resulting displacements, velocities, and accelerations. This requires solving one or more differential equations. The inverse problem is, as its name says, the inverse of the other. In this approach, the displacements, velocities, and accelerations are known or assumed, and we solve for the forces and torques that result. This requires only solving an algebraic equation. In this chapter we will set up both methods for cam-follower analysis. Sections 9.1 to 9.3 present fundamental dynamic principles needed to understand both analyses. The rest of the chapter presents the inverse or kinetostatic solution whose main value is to predict cam-follower separation. The forward or dynamic solution will be fully developed in Chapter 10. Both approaches are useful in this application of a force-closed (spring-loaded) cam-follower system, but the forward solution is capable of giving more information about the system's vibratory behavior both before and after separation than is the kinetostatic solution.
Figure 9-la shows a simple plate or disk cam driving a spring-loaded, roller follower. This is a force-closed system which depends on the spring force to keep the cam and follower in contact at all times. It is assumed that the moving follower parts are significantly stiffer than the follower joint-closure spring. Figure 9-lb shows...
