Page 158 - Cam Design Handbook
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THB5 8/15/03 1:53 PM Page 146
146 CAM DESIGN HANDBOOK
1
Damping Ratio = 0.2 (C = C ) f
s
Spline (k = 10)
Optimized Polydyne
Cam displacement .5
0
0 .5 1
Normalized time
FIGURE 5.30. Cam displacements for both spline (k = 10) and optimized polydyne with damping
ratio = 0.2 (C s = C f) in Example 8.
where
∫+
Aa s 1
∂ s
B ∫ 1
∂f
2
∂ s
C ∫ 1
∂ s 2
2
D ∫ A + B + A C .
2
2
2
The offset (pitch) surface of the cam, which is useful for the cutter path generation, can
be described by the analytical expression
R Bsinf
Ï Acosf - ( r - )( 2 + Acosf 2 ) ¸
Ô 2 Ô
Ï x ¸ D
R
R Bcosf
Ô
Ô Ô Ô Ô ( r - )( - Asinf ) Ô
Ì
Ì y ˝ = - Asinf 2 - 2 2 ˝ (5.35)
R
Ô Ô Ô D Ô
z Ó R ˛ Ô ( r - ) Ô
R AC
Ô Ó s -- D Ô
2
˛
