4 starting time and stopping time – Yaskawa SGDB User Manual
Page 299

5.3 SERVOPACK Ratings and Specifications
289
5.3.4 Starting Time and Stopping Time
The motor starting time (tr) and stopping time (tf) under constant load are calculated by
the following formulas. The motor viscous torque and friction torque are ignored.
Starting Time:
Stopping Time:
tf =
2π ⋅ N
m
(J
M
+ J
L
)
60 ⋅ (T
PM·
–T
L
)
[s]
[ms]
tf =
2π ⋅ N
m
(J
M
+ J
L
)
60 ⋅ (T
PM·
+ T
L
)
N
M
: Motor speed used (r/min.)
J
M
: Motor moment of inertia (kg¡m
2
)
(GD
2
M
/4)
. . . . . . . . . . . . . . . . . . . . . . . .
J
L
: Load converted to shaft moment of inertia (kg¡m
2
)
(GD
2
L
/4)
. . . . . . . . .
T
PM
: Maximum instantaneous motor torque obtained in combination with SERVOPACK
(N¡m)
T
L
: Load torque (N¡m)
To convert the motor current value into an equivalent torque value, use the following formula:
Motor torque constant × motor current value (effective value)
Motor Torque
Time
Motor Speed
Motor Torque (size) - Motor Speed Timing Chart
Time
T
L
T
PM
T
PM
N
M
5