Classification Of Rotor Pumps

Rotor pumps are divided into gear pump, Screw pump, rotary piston pump (cam pump, roots pump), flexible impeller pump, sliding vane pump, hose pump, etc. according to the structural type.
(1) Gear pump
Gear pumps mainly consist of gears, shafts, pump bodies, pump covers, bearing sleeves, shaft end seals, etc. A rotary pump that relies on the variation and movement of the working volume formed between the pump body and the meshing gear to transport liquid or pressurize it. Gear pumps have two types of structures: external and internal. External gear pumps are also divided into double gear pumps, three gear pumps, and five gear pumps, with external gear double gear pumps being the most commonly used. A pair of meshing gears and pump bodies separate the suction and discharge cavities. When the gear rotates, the volume between the teeth at the separation point of the suction cavity side teeth gradually increases, the pressure decreases, and the liquid enters the teeth under the pressure difference. As the gears rotate, the liquid between the teeth is carried to the discharge chamber. At this point, the volume between the teeth at the meshing point of the gear teeth on the discharge chamber side gradually decreases, and the liquid is discharged.
(2) Screw pump
The Screw pump is composed of a pump shell and one or more screws. The working principle of the double Screw pump is very similar to that of the gear pump. It relies on the intermeshing screws to absorb and deliver liquid. According to the number of screws, Screw pump can be divided into single Screw pump, double Screw pump and three Screw pump, among which double Screw pump can be divided into closed and non closed types.
(3) Rotary piston pump
There are many types of structures for rotary piston pumps, among which the most commonly used are cam pumps, Roots pumps, etc.
Cam pump is a multi-purpose bidirectional displacement pump, which is one of the most advanced fluid conveying equipment in the world. It adopts two synchronous rotors, which are driven by a pair of external synchronous gears. The rotors rotate synchronously in the opposite direction under the drive of the transmission shaft. There is no contact between the rotors or between the rotor and the pump body, but a gap line or surface seal is formed, thus forming a high vacuum and discharge pressure, Especially suitable for the transportation of food, medicine, corrosive and high viscosity media.
Roots pump and cam pump have similar structural forms, but the difference is that the liquid seal also needs to be formed between the rotors. Large pumps are mostly arranged with simple supports, and their processing is simpler than cam pumps, with lower working pressure than cam pumps.
(4) Flexible impeller pump
Flexible impeller pumps belong to positive displacement rotor pumps. A flexible impeller pump consists of a flexible impeller made of rubber, a pump body, a mechanical seal, and a rotating shaft. When the impeller rotates away from the eccentric section of the pump casing, the flexible impeller blades straighten to create a vacuum, and the liquid is sucked into the pump. As the impeller rotates, the liquid then moves from the suction side to the discharge side. When the impeller blades come into contact with the eccentric section of the pump casing, the working volume changes and the liquid is smoothly discharged out of the pump.
(5) Sliding vane pump
The rotor with radial grooves is installed in the pump body with an eccentric stator, and the sliding plates are located in the radial grooves of the rotor. The sliding plates can be two or more pieces. When the rotor rotates, under the action of centrifugal force, the sliding plates are thrown out of the rotor body and slide along the inner surface of the stator. These sliding blades and stators form a sealed cavity that gradually increases with eccentricity. As they continue to rotate, the cavity decreases to zero and the liquid filled between the rotor and sliding blades begins to suck in from the suction area and then press towards the discharge area, completing the liquid transportation process.