Page 266 - Cam Design Handbook

THB9 9/19/03 7:26 PM Page 254

254 CAM DESIGN HANDBOOK

FIGURE 9.1. Crowned rollers in elastic contact.

3 p
p = . (9.2)
0
2p ab
The semiaxes a and b of the ellipse of contact are
È 3 PD ˘ 13
a = m (9.3)
Í Î4 AB˚ ˙
+
È 3 PD ˘ 13
b = n (9.4)
Í Î4 AB˚ ˙
+
where the values of m and n are given in Table 9.1.
In Eqs. (9.3) and (9.4), D is a factor determined by the relationship between the mate-
rials where the subscripts 1 and 2 refer to the first and the second contacting bodies
1 - m 2 1 - m 2
D= 1 + 2 . (9.5)
E E
1 2
A and B are factors determined by various radii of curvature of the contacting bodies. If
we designate r 1, r 2 as the minimum radii of curvature, r¢ 1, r¢ 2 as the maximum radii of