Abstract:

ESDU 83027 is one of a comprehensive series dealing with the design of cam and follower systems. It gives methods using portions of symmetrical DRD cam law motion segments described in ESDU 82006 in combination with and/or superimposed on periods of constant velocity to satisfy "special" motion requirements. These special motions include a requirement for an asymmetrical acceleration characteristic, a period of constant velocity in a motion segment, motion without dwell between follower rise and return movements (DRRD motion), or a precision point where the follower position is given for a particular cam angle. The methods make use of a blend factor which is derived from the standard normalised cam law formulae. The resulting blended motion will have continuous displacement and velocity characteristics and can in most cases, if required, achieve continuous acceleration. Tables of blend factor and cam law parameters are given for eight DRD cam laws and six worked examples illustrate the application of the method in design to meet specified requirements for the follower motion.