User Manual
Appendix
EM1 Series AC Servo Motors
EM1-01-0-EN-2110-MA
Page
64
of
72
13
Appendix
13.1
AC Servo Motor Selection
The way to select a suitable motor based on speed, moving distance, and loading inertia is
described in the following contents. The basic process for sizing a motor is as below table.
Basic process of AC servo motor sizing
Provide mechanical transmission mechanism
Provide motion profile
Provide load condition
Load inertia calculation
Motor speed calculation
Motor torque calculation
Motor sizing completed
Symbol
t
f
Moving time (sec)
J
b
Ball screw inertia (kgm
2
)
ta
Acceleration time (sec)
J
P
Pulley inertia (kgm
2
)
td
Deceleration time (sec)
J
T
Rotary table inertia (kgm
2
)
t
c
Cycle time (sec)
J
W
Work pieces inertia (kgm
2
)
N
Motor speed (rpm)
J
Total inertia (kgm
2
)
J
L
Load inertia (kgm
2
)
D
Outer diameter (m)
J
r
Rotor inertia (kgm
2
)
W
Work piece weight (kg)
T
p
Peak torque (Nm)
D
Inner diameter (m)
T
t
Travelling torque (Nm)
L
Length (m)
n
Work pieces amount (pcs)
a´
Side length (m)
b´c
T
a
Acceleration torque (Nm)
T
d
Deceleration torque (Nm)
