Chapter 1. Description of Hybrid Servo Drives I VFD-VJ   
  
 
1-8
 
1-3-2 Selection of Pump for Hybrid Servo Motor 
Select a pump with a suitable displacement based on the required flow rate and motor speed; 
  If low noise is required, you can choose the screw pump or internal gear type. If a high 
volumetric efficiency is required, you can choose the piston pump or dual displacement 
piston pump. 
  Comparison of Commonly Used Pump (This may vary for different pump manufacturers). 
Type of Oil 
Pump 
Volumetric 
Efficiency 
Flow Pulsation  Rotation Speed  Noise 
Internal Gear 
Pump 
Low Medium Medium Low 
Piston Pump  High  Low  Low  High 
Screw Pump  Medium  High  High  Medium