What is the difference between a quantitative vane pump and a variable vane pump?
Under the condition of constant speed, the one with constant pressure and adjustable output flow is a variable vane pump, and the one with constant pressure and flow cannot be adjusted is a quantitative vane pump. Their biggest difference is that the shaft of the variable vane pump is conveniently installed. Simply speaking, after the speed of the quantitative vane pump is selected, its flow and pressure are determined and cannot be adjusted. The output flow of the variable vane pump can be adjusted automatically according to the pressure change of the hydraulic system (the size of the external load), that is, the output flow is small when the pressure is high, and the output flow is large when the pressure is low, so that it can save the number of hydraulic components, thereby Simplifies the oil circuit system, and can reduce oil heating. The disadvantage is that the flow pulsation is serious, the pressure of the hydraulic system is not stable, the life of the pump is short, and the bearing of the pump is easy to break, because it is easy to install, and the noise of the pump is loud. The vane pump can realize the variable by adjusting the eccentricity, and the piston pump can realize the variable by adjusting the angle of the slide plate.
The working principle of the quantitative vane pump: the sealed volume formed by the stator and the rotor distribution plate is divided into several parts by the blades. Every time the rotor rotates once, each sealed space completes oil suction and pressure twice, so it is called a quantitative vane pump.
The working principle of the variable vane pump: The variable vane pump can adjust the flow rate of the pump by changing the eccentricity e of the rotor and the stator, so that the hydraulic system can use energy reasonably when it is working and feeding, with high efficiency and low oil temperature rise. The change of eccentricity e can only be realized by moving the stator, because the position of the rotor and the transmission shaft is limited by the shaft of the prime mover.