Page 209 - The Tribology Handbook

Screws B9

PERFORMANCE

1 ooc 100

500 50

100 10

m
w
5 z
z
n 50 5 0
a k
s 0
a
s

10 1

5 For ball and roller screws 0.5
the load is the dynamic
capacity for an L $0 life
of one million screw
revolutions

0.2

1 0.1
20 40 60 80 100 120
SCREW DIAMETER mm

Figure 9.1 The axial load capacity of various types of screw

Mechanical efficiencies of screws

Plain screws 3o0/o-50~o approximately, with larger diameter screws tending to have the lower values.
Roller screws 65 Yo-85 7'0
Bail screws 75 % -9O'Yo

B9.2