Working principle of servo oil pump and its performance comparison with variable displacement pump

The servo oil pump is driven by a servo motor, and the servo oil pump to be tested is driven by an AC servo motor. Servo motors belong to the category of control motors, and their main function is to transmit and convert signals, such as servo motors converting voltage signals into torque and speed, and so on. The main requirements for controlling motors are: sensitive and accurate action, reliable operation, low power consumption, etc., which are also applicable to servo motors.
 
For variable displacement pump (open-loop or closed-loop) hydraulic systems, it has the following necessary characteristics:
 
The essential characteristics of a hydraulic system are:
 
A Energy saving; B pressure and flow ratio control; C action has high response.
 
Two essential characteristics of hydraulic pump:
 
A volume speed regulation (variable flow rate); B high mechanical efficiency; The pressure control state and flow control state can be smoothly switched.
 
Similarly, for servo oil pump hydraulic systems, they should also have their necessary characteristics. We can first understand the working principle of servo motors, which will help us derive the necessary characteristics of servo oil pump hydraulic systems.
 
AC servo motors are usually single-phase asynchronous motors, with two structural forms: squirrel cage rotor and cup-shaped rotor. Like ordinary motors, AC servo motors are also composed of a stator and a rotor. There are two windings on the stator, namely the excitation winding and the control winding, with a spatial difference of 90 ° electrical angle between the two windings. The rotor of a cage rotor AC servo motor is the same as that of a regular three-phase cage motor.