Page 563 - Cam Design Handbook

THBAP 9/19/03 7:29 PM Page 551

APPENDIX B

BASIC CAM CURVE FACTORS

Table B.1 SIMPLE HARMONIC MOTION Table B.3 MODIFIED TRAPEZOIDAL CURVE
FACTORS 552 FACTORS 554
Table B.2 CYCLOIDAL MOTION FACTORS Table B.4 MODIFIED SINCE CURVE FACTORS
553 555

Curve factors have been developed to establish the cam profile, the velocity, and acceler-
ation of the follower easily. These factors are tabulated data calculated from the curve
equations in Chaps. 2 and 3. In the tabulated values the cam angle factor goes from 0° to
120° and the displacement factor K goes from 0 to 1. To determine increments on a cam,
the given values of q must be multiplied by the ratio b/120. For example, if b is 60°, the
1
increment is 60/120 = / 2 degree.
The following equations can be employed to establish the follower characteristics:
Displacement y = Kh, in
Ê w ˆ
Velocity y = C hÁ ˜ , in/sec
v Ë b ¯
2
Ê w ˆ
Acceleration y = C hÁ ˜ , in/sec 2
a Ë b ¯
where K, C V, and C a are the displacement factor, the velocity factor, and the acceleration
factor, respectively; w is the camshaft speed, deg./sec.; and h is total rise in inches for cam
angle b, degrees.

551

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