A、 Core structure

Composed of active screw, driven screw, pump body liner, inlet and outlet, seal, and drive motor, it is divided into single screw, twin-screw, and triple screw (the most commonly used triple screw in industry).

The screw teeth mesh with each other, forming a closed and continuous sealed chamber between the screw and the liner.

B、 Basic operating logic (mainly based on three screw pump)

1. The motor drives the middle active screw to rotate, and the meshing drives the driven screws on both sides to rotate synchronously in the opposite direction;

2. The screw tooth groove, inner wall of the liner, and adjacent screw meshing surfaces enclose independent sealed cavities in sections;

When the screw rotates, the sealing chamber slowly moves along the axial direction of the screw from the suction end to the discharge end;

4. Inlet side: The cavity volume increases, forming negative pressure, and the liquid is sucked into the cavity;

5. The medium carried by the cavity continues to move forward, and when it reaches the outlet side, the volume is continuously compressed, and the liquid is squeezed and pressurized before being sent out from the discharge outlet;

6. The cavity continuously regenerates, moves, and compresses to achieve continuous pulse free liquid delivery.

C、 Difference in subdivision types

1. Three screw pump (hydraulic oil, lubricating oil, fuel)

Three screws, high pressure, stable flow, and low noise; Only conveying lubricating fluids, mostly used for supplying oil to machine tool hydraulics and generator sets.

2. Twin screw pump (for crude oil, asphalt, sewage, viscous media)

Two screws, the screws do not touch each other and are sealed by gaps; It can transport media containing small amounts of particles and without lubrication, with a wide range of viscosity for transportation.

3. Single screw pump (sludge, sauce, high viscosity granular materials)

A metal rotor+rubber stator; The rotor rotates eccentrically, and the spiral sealed chamber propels the material, suitable for high viscosity, solid-liquid mixed media (sewage sludge, food slurry).

D、 Key features

1. The conveying flow is uniform, with almost no pressure pulses;

2. Strong self-priming ability;

3. Smooth operation and low vibration noise;

4. Suitable for high viscosity oils and viscous liquids;

5. Positive displacement pump: If the outlet is blocked, the pressure will increase sharply and must be protected by a safety valve.

Simple and easy to summarize

The screw engages and rotates a series of moving "sealed small pockets", which are filled with liquid at the inlet. The pockets are pushed forward by rotation, and then squeezed and pressurized at the outlet for continuous transportation.

The above:How to maintain hydraulic gear pump?