Gear pumps are mainly composed of gears, shafts, pump bodies, pump covers, bearing sleeves, shaft end seals, etc. It is a rotary pump that relies on the change and movement of the working volume formed between the pump body and the meshing gears to convey liquid or to pressurize it. Gear pumps have two types of structure: external and internal. External gear pumps are also divided into double gear pumps, triple gear pumps and five gear pumps, with external double gear pumps being the most common.
Screw pumps consist of a pump casing and one or more screws. The operating principle of a twin-screw pump is very similar to that of a gear pump, which relies on intermeshing screws to suction and delivery of liquid. Screw pumps are divided into single-screw pumps, twin-screw pumps and triple-screw pumps according to the number of screws, of which twin-screw pumps are of two types: closed and non-closed.
Rotary piston pumps
There are many different types of rotary piston pump structures, the most common of which are lobe pumps, Roots pumps, etc.
The lobe pump is a multi-purpose bi-directional displacement pump, one of the most advanced fluid transfer equipment internationally. It uses two rotors with synchronous motion, the rotors are driven by a pair of external synchronous gears, the rotors are driven by the drive shaft for synchronous counter directional rotation, the rotors do not touch each other and between the rotors and the pump body, but form a gap line or face seal, thus constituting a high vacuum and discharge pressure, especially suitable for food, pharmaceutical, corrosive and high viscosity media.
Flexible impeller pumps
Flexible impeller pumps are volumetric rotor pumps. The flexible impeller pump consists of a flexible impeller made of rubber, pump body, mechanical seal and drive shaft.
The rotor with a radial groove is mounted in a pump body with an eccentric stator, and the slider is located in the radial groove of the rotor. These slides and the stator constitute a sealed cavity with the eccentric increase cavity gradually increased, continue to rotate, the cavity is reduced to zero, and filled in the rotor, the cavity between the slides liquid began to suck in from the inlet area, and then pressed to the discharge area to complete the liquid transfer process.