Page 239 - Cam Design Handbook

THB8 9/19/03 7:25 PM Page 227

CAM MECHANISM FORCES 227

Displacement y 1 1 4 " 15 16 " 2 Transition

point
5 16 "
1
20 dwell
Dwell 40 120
(b) Displacement 160° 160°
+
diagram. Cam angle q, degrees
+20,200 in/sec 2 +20,200 in/sec 2
+ +
(a) Cam-follower (c) Acceleration,
schematic. in/sec 2 – –
–6750 in/sec 2

+104 lb +104 lb
+ +
(d ) Inertia force, lb
– –
–35 lb

+10 lb
(e) External load, lb +

+2 lb
(f ) w, weight of +
follower, lb
+16 lb +16 lb
(g) Combined above + Combined loads +
loads for spring Critical design point
design, lb +12 lb +12 lb
– –
+14 lb –23 lb +14 lb
+30 lb +30 lb
Spring load
+146 lb +78 lb +146 lb
+130 lb +130 lb
+90 lb
(h) Total load +55 lb
on cam, lb +7 lb +55 lb +7 lb
+26 lb
FIGURE 8.7. Cam surface load example.