- 165 -
Fig. 7-1 Characteristic curve of servo motor (permanent magnet synchronous
servo motor)
From the figure above, after the motor speed is higher than the rated speed,
and with the motor speed, the motor torque will gradually decrease. But when
the motor speed exceeds 150% of the rated speed, the motor torque will
decline rapidly, so the speed segment cannot be used as the work of the servo
motor speed fragment uses.
Therefore, select 140% of the rated speed to be the motor maximum speed.
Motor rated rotation speed: V（rpm）＝Vmax（rpm）/140％
Note: For better control results, please select 130% of he motor rated speed to
be the maximum speed.
Servo motor rated toque selection:
According to energy conservation law, plastic maximum output power is
P2max（kW）＝P1（kgf/cm
2
）×0.9807（kgf/cm
2
/bar）×Q（L/min）
Motor maximum output power is (Follow 80 percent of the energy conversion
efficiency, Including motor efficiency, hydraulic transmission efficiency,
mechanical transmission efficiency, etc.) P3max（kW）＝P2max（kW）/ 80％
Servo motor maximum output torque is: Tmax（Nm）＝P3max（kW）×9550/
Vmax（rpm）
Due to injection molding machine requires continuous output high torque when
packing pressure,according to the servo motor (servo motor) characteristic
curve, servo motor overall job status is in the DT-100 ° c (s1) and (S3 20
percent between 5MIN).
Therefore, select 180% of the motor rated torque to be the maximum torque.
Servo motor rated torque is: Tn（Nm）＝Tmax（Nm）/180%
Note: If selecting the double displacement plunger pump or dual-gear pump,
Motor rotation speed (percentage
of the motor rotation speed)
25％ 50％ 75％ 100％ 125％ 150％
Motor torque (percentage
of the motor torque )
50％
100％
150％
200％
250％
300％
S1 65℃ DT
S1 100℃ DT
S3 20% 5MIN
To Next Page
Loading...
