Page 415 - Cam Design Handbook

THB13 9/19/03 7:56 PM Page 403

CAM SYSTEM DYNAMICS—RESPONSE 403

4

S NA 2

1

0
0 2 4 6 8 10 12
T / T N
1
(a) Primary spectrum.

S NA

0 2 4 6 8 10 12
T / T N
1
(b) Residual spectrum.
FIGURE 13.2. Acceleration spectrum of modified trapezoidal cam
(DRS) with 5% damping.

display of the dynamic characteristics of a number of cam profiles is presented. It should
be noted that damping has a significant effect on both the primary and the residual
responses. The more significant effect is on the residual response. The magnitude of
damping is very difficult to firmly establish. The effect of damping is to smooth out the
curves and reduce the sharpness of the peaks in the residual responses.
Figure 13.3 presents the s NA of selected cams all having zero damping. Figure 13.4
illustrates a comparison of the maximum primary vibrations of many important cam pro-