Page 55 - Cam Design Handbook

THB2 8/15/03 12:48 PM Page 43

BASIC CURVES 43

2 p
w
Cam angular velocity = 300 ¥ = 31 42 rad sec
.
60
p
Total angle =150 ¥ = 262 rad
b
.
180
From Eq. (2.51) the displacement
h Ê pq ˆ
y = Á1 - cos ˜
2 Ë b ¯
.
3 Ê p ¥ 0524 ˆ
.
= 1 - cos = 0143 in
.
4 Ë 262 ¯
Equation 2.52 gives velocity
hp pq
y ¢ = sin in rad and with Eq. 2.8, the velocity
2 b b
hpw pq
y ˙ = sin in sec
2 b b
1
.
1 ¥ p ¥ 31 42 p ¥ 0524
.
.
= 2 sin =16 6 ips
2 ¥ 2 62 262
.
.
Acceleration by Eq. (2.53)
hp 2 pq
2
y ¢¢ = cos in rad and with Eq.(2.9), the acceleration
2 b 2 b
2
h Ê pw ˆ pq 2
y ˙˙ = Á ˜ cos in sec
2 Ë b ¯ b
.
.
3 Ê p ¥ 31 42 ˆ 2 p ¥ 0524
= Á ˜ cos = 862 in sec 2
.
4 Ë 2 ¥ 2 62 ¯ 262
.
Solution (b)
In App. B-1 for simple harmonic motion
¥
q ¥ 120 30120
Point # = = 24 0 .
b 150
deg
rev ¥
360300 rpm
w = =1800 deg sec
60sec min
Displacement
y = Kh
.
.
= 09549 ◊1 5 = 014324 in
.
.
where K = 09549 at point #24