Abstract:

ESDU 06005 provides guidance on the use of computer programs, W0605 and A0605, to aid the selection of cam laws suitable for symmetric Dwell-Rise-Fall-Dwell (DRFD) follower motions, i.e. those having equal rise and fall periods. They include motions having an intermediate constant-velocity component in both the rise and fall actions. The program also analyses the complete follower motion. The complete rise and fall segment of the motion is defined by either a single cam law or by blending two components of cam laws chosen in such a way that there is continuity of follower displacement, velocity and acceleration between the two components. The blending process, which may include a constant velocity segment, is accomplished in one of five ways, by:

• ensuring continuity of jerk at the blend point,
• specifying the Blending Ratio,
• specifying the Acceleration Ratio,
• specifying the maximum follower velocity,
• or by specifying the maximum follower acceleration.

A previously issued Item in the series of DRFD cam laws is ESDU 06002, which provides guidance on the analysis and selection of these types of symmetric motion, including the converse DFRD and DFVRD follower actions. Other issued Data Items in the series include ESDU 06003, that refers to asymmetric follower motions of the DRFD, DFRD, DRVFD and DFVRD types having unequal periods for the rise and fall actions, and ESDU 06004 that contains examples that illustrate the application of these motions.