346 DESIGN OF MACHINERY CHAPTER 8 TABLE 8-1 Notation Used in This Chapter t=time,seconds 0=camshaft angle,degrees or radians(rad) camshaft angular velocity,rad/sec B=total angle of any segment,rise.fall,or dwell.degrees or rad h=total llft (rise or fall)of any one segment.length units s or S=follower displacement,length units v=ds/de follower velocity.length/rad V=ds/dt=follower velocity,length/sec a=dv/de=follower acceleration,length/rad2 A=dV/dt=follower acceleration.length/sec2 /=da/de=follower jerk.length/rad3 J=dA/dt=follower jerk,length/sec3 s v ajrefer to the group of diagrams,length units versus radians S V A Jrefer to the group of diagrams,length units versus time Ro=base circle radius,length units Ro=prime circle radius.length units R,=roller follower radius.length units e=eccentricity of cam-follower.length units o=pressure angle.degrees or radians p radius of curvature of cam surface.length units Ppitch=radius of curvature of pitch curve,length units Pmin=minimum radius of curvature of pitch curve or cam surface,length units discussed.The computer program DYNACAM will be used throughout the chapter as a tool to present and illustrate design concepts and solutions.A user manual for this pro- gram is in Appendix A.The reader can refer to that section at any time without loss of continuity in order to become familiar with the program's operation. 8.1 CAM TERMINOLOGY Cam-follower systems can be classified in several ways:by type of follower motion, either translating or rotating (oscillating):by type of cam,radial,cylindrical,three-di- mensional;by rype of joint closure,either force-or form-closed;by type of follower. curved or flat,rolling or sliding:by rype of motion constraints,eritical extreme posi- tion(CEP).critical path motion(CPM):by rype of motion program,rise-fall(RF), rise-fall-dwell(RFD).rise-dwell-fall-dwell(RDFD).We will now discuss each of these classification schemes in more detail