Selection Of Hybrid Servo Drives And Motors - Delta VFD-VJ Series User Manual

1-3 Overview of Hybrid Servo Systems
Injector
Controller

1-3-1 Selection of Hybrid Servo Drives and Motors

Due to the differences in the hydraulic system in practical applications, the following choice of
drives and motors is provided as a reference.
In the following example, a flow of 64L/min and maximum holding pressure of 175Bar are
used.
1. Pump Displacement per Revolution
Based on the maximum flow of the system (L/min), the pump displacement per revolution
(cc/rev) can be calculated.
Example: If the maximum flow of the system is 64L/min and the highest rotation speed of
2. Maximum Torque of the Motor
Based on the maximum pressure (Mpa) and pump displacement per revolution (cc/rev),
the maximum torque can be calculated.
Example: For the required maximum pressure of 17.5 Mpa and pump displacement per
Torque = 17.5*32*1.3/(2*pi) = 116 N-m, where the factor 1.3 is used to compensate the
total loss in the system.
3. Rated Torque and Rated Power of the Motor
At the maximum pressure for the holding pressure, the required torque should be 1.5
times of the motor's rated torque or less (depending on the data provided by the motor's
Pressure Command
(0~10V)
Flow Rate Command
Delta Hybrid
(0~10V)
Servo
Drive
PG Card
RST
Power
Terminal
Encoder signal
AC
FAN
220V/380V
the motor is 2000rpm, the displacement per revolution is 64/2000*1000 = 32
cc/rev.
revolution of 32cc/rev
Pressure
Feedback
(0~10V)
U V W
Brake resistance/
Brake Unit
1-5
1. Use and Installation
Pressure
Sensor
Oil
Pump