Page 375 - Cam Design Handbook

THB12 9/19/03 7:34 PM Page 363

CAM SYSTEM DYNAMICS—ANALYSIS 363

F x

y

(a) Parabolic cam curve.

y
y
x x

(b) Simple harmonic cam curve.
y
x

(c) Cycloidal cam curve.
FIGURE 12.2. Single-degree-of-freedom response of basic dwell-rise-dwell cam acceleration curves.

12.3.2 Single Degree-of-Freedom System Compliance
The solution of the single-degree-of-freedom cam-follower system is shown in the previ-
ous section. In this section we investigate the analysis and response of highly elastic
systems such as the high-speed automotive valve-gear system and some special textile
machines. Figures 12.3 and 12.4 show the displacement, velocity, and acceleration
follower response curves of the simple harmonic and cycloidal basic cam curves. The
w
curves show the response for small values of n, where n = n , the ratio of the natural
w
frequency to the excitational frequency. For more rigid systems (n > 4) the analysis and
the curves will be similar, having higher frequencies and smaller amplitudes. In both
figures we see that the follower mass catches up with and overshoots the forcing cam dis-