Page 180 - Cam Design Handbook

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168 CAM DESIGN HANDBOOK

is one of the reasons oscillating followers are a more popular design choice than translat-
ing followers.

6.3.4 Pressure Angle Forces—Translating Flat-Faced Follower
The pressure angle of a radial cam with a translating flat-faced follower has the advan-
tage of being zero at all times. Thus the side thrust or jamming effect on translating
flat-faced followers is inconsequential compared to that of translating roller followers.
Nevertheless a force analysis is presented for comparison. The normal forces to the fol-
lower are N 1 and N 2 with their respective frictional components; Fig. 6.7. The new symbols
are:
l = the distance from the normal force F to the axis of the follower, in
m c = coefficient of friction between the cam and the flat-faced follower surface
m = coefficient of friction of follower bearing

For the “follower,” SF x = 0,SF y = 0 and the moments about point q are for the rising cycle
with
+
SF = 0 = -m F N + N . (6.15)
x c 1 2
0
+
SF == - L F - m N - m N (6.16)
y 2 1

FIGURE 6.7 Forces for radial cam, translating
flat-faced follower.