A-14
Engineering Guide CDA3000
Appendix A Formula bank
c
Rim friction
d
Wheel diameter
m
d
m
Mean thread diameter
m
d
w
Axle/shaft diameter
m
F
Longitudinal force in screw/
threaded spindle N
F
N
Normal force
N
F
R
Friction force with Coulomb friction
N
F
W
Tractive resistance to rolling friction
N
f
Lever arm of rolling friction
m
g
Acceleration due to gravity
m/s²
m
Mass kg
M
R
Friction torque
Nm
α
Angle of inclination of inclined plane
deg.
µ
l
Coefficient of friction in longitudinal movement
µ
r
Coefficient of friction in rotational movement
ρ
Friction angle in threaded spindles
deg.
Friction force of Coulomb friction (dry friction)
Tractive resistance to rolling friction
Friction torque in thread
Table 7.13
Friction
A.2.5 Friction
F
R
F
N
µ
l
⋅
m g
µ
l
α
cos
⋅ ⋅ ⋅
=
=
F
W
m g
2
d
--
d
W
2
------
µ
r
f
)
c
+
+
⋅
⋅
⋅ ⋅
=
M
R
F
d
m
2
------
ρ
tan
⋅
⋅
=