2-4 Examining operating status
Selection guidelines
2-8
1
2
3
4
5
6
7
8
9
10
11
Apx
Sel
ect
ion gui
del
ines
Load torque calculation
Calculate the load torque as follows:
Rotary motion
The rotary torque for the rotating mass W on
the ring of radius r from the center of rotation is
shown in the figure to the right.
T: Rotary torque (N·m)
μ: Friction coefficient
W: Mass (kg)
r: Average radius of friction side (m)
The right graph gives a calculation example
when the friction coefficient μ is assumed as 0.1
and the horizontal axis and vertical axis
represent mass and rotational radius of friction
side, respectively. The actuator toque shown in
the graph indicates 20% of the maximum
torque.
Linear operation (horizontal operation)
The rotary torque when the mass W moves horizontally due to the screw of pitch P is shown below.
T: Rotary torque (N·m)
μ: Friction coefficient
W: Mass (kg)
P: Screw feed pitch (m)
Linear operation (vertical operation)
The rotary torque when the mass W moves vertically due to the screw of pitch P is shown below.
r
×
W
×
μ
×
8
.
9
=
T
1
10
30
0.3
3
10
100
300
30
Mass W (kg)
Radi
us
r of fr
ic
tion s
ide (
m
m
)
0.1 N·m
Example of rotary torque calculation (friction coefficient = 0.1)
FHA: shows 20% torque lines of maximum torque
0.7 N·m
1 N·m
10 N·m
2 N·m
5 N·m
3 N·m
0.5 N·m
0.3 N·m
0.2 N·m
FHA-8C-30
FHA-8C-50
FHA-8C-100
FHA-11C-30
FHA-11C-50
FHA-11C-100
FHA-14C-30
FHA-14C-50
FHA-14C-100
Mass: W
Pitch: P
Friction: μ
π
×
×
×
µ
×
=
2
P
W
8
.
9
T
π
×
×
×
=
2
P
W
8
.
9
T
Pitch: P
Mass: W
Radius: r
Mass: W
Friction: μ
