Starting And Stopping Time - YASKAWA SGM Series User Manual

3.2 Starting and Stopping Time

The motor starting (tr) and stopping time (tf) with a constant load are calculated using the following
equations. Motor viscous torque and friction torque have been ignored.
Starting time: tr = 104.7 ×
Stopping time: tf = 104.7 ×
N : Rated motor speed (r/min)
R
J : Motor moment of inertia (kg/m
M
J : Load converted to shaft moment of inertia (kg/m
L
T : Maximum instantaneous motor torque obtained in combination with SERVOPACK (N⋅m)
PM
T : Load torque (N⋅m)
L
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
Motor speed
N (J
R
Kt ⋅ I
N
Kt ⋅ I
2
Figure 3.2 Motor Torque − Motor Speed Timing Chart
3 -3
+ J )
M L
[ms]
(α–β)
R
(J + J )
R M L
[ms]
(α + β)
R
2
)...(GD /4)
M
2 2
)...(GD /4)
L
Time
Time
3.2 Starting and Stopping Time
3