Screw pump vs. cam rotor pump
author: 003
2026-08-31
Screw pump vs cam rotor pump
Working principle
Screw Pump: A metal screw rotates eccentrically inside a rubber stator, continuously forming a sealed chamber to push the medium. The seal is achieved through the cooperation of the screw and the rubber stator, resulting in smooth material flow with virtually no flow pulsation.
Cam Rotary Pump: Synchronous gears drive two sets of cam rotors to rotate in opposite directions, with the rotors not in contact with each other. The medium is transported through a chamber formed by the rotors and the pump casing. All flow-through contact parts are made of metal.
Cam Rotary Pump: Synchronous gears drive two sets of cam rotors to rotate in opposite directions, with the rotors not in contact with each other. The medium is transported through a chamber formed by the rotors and the pump casing. All flow-through contact parts are made of metal.
Key performance comparison
1. Flow and Pressure Performance
Screw Pump: Material output is almost pulsating, achieving high output pressure, suitable for long-distance conveying processes; flow remains stable even with pressure fluctuations. Due to the limitations of the rubber stator, the operating speed should not be too high.
Rotor Pump: Slight flow pulsation exists, and the upper limit of output pressure is slightly lower than that of the screw pump; stable performance under medium pressure conditions, flow can be adjusted via frequency converter, adapting to various production processes such as material transfer and filling.
2. Material Adaptability, Particle Passage, and Shear
Screw Pump: More suitable for pure materials without hard particles, such as syrups and pastes. The rubber stator is easily worn by hard particles, which will reduce conveying capacity over time. Overall shear is low, but the internal extrusion structure will exert some compression on large fruit pulp particles.
Rotor Pump:
Screw Pump: Material output is almost pulsating, achieving high output pressure, suitable for long-distance conveying processes; flow remains stable even with pressure fluctuations. Due to the limitations of the rubber stator, the operating speed should not be too high.
Rotor Pump: Slight flow pulsation exists, and the upper limit of output pressure is slightly lower than that of the screw pump; stable performance under medium pressure conditions, flow can be adjusted via frequency converter, adapting to various production processes such as material transfer and filling.
2. Material Adaptability, Particle Passage, and Shear
Screw Pump: More suitable for pure materials without hard particles, such as syrups and pastes. The rubber stator is easily worn by hard particles, which will reduce conveying capacity over time. Overall shear is low, but the internal extrusion structure will exert some compression on large fruit pulp particles.
Rotor Pump:
Better compatibility with soft granular materials, able to smoothly convey materials containing fruit pulp, fruit pieces, and soft fibers; particles are transported as a whole within the chamber, resulting in less material damage; low shear level, suitable for materials that are prone to foaming and whose activity is easily destroyed by agitation, such as dairy products, fermentation broths, and creams. 3. Cleaning and Sterilization (CIP/SIP)
Screw Pump:
Screw Pump:
Complex internal helical groove structure, with a rubber stator as the core component. Supports online cleaning, but the complex flow path of the cleaning medium in the helical grooves makes material residue prone to occur; the rubber parts have limited temperature resistance, which may restrict some high-temperature steam sterilization scenarios. For thorough cleaning, it is recommended to disassemble the pump body for cleaning.
Cam Rotor Pump:
Cam Rotor Pump:
Streamlined pump chamber design with fewer dead angles and mirror-polished inner walls; supports complete online cleaning (CIP) and steam sterilization (SIP), allowing the cleaning medium to thoroughly flush the pump chamber; easy to disassemble and assemble, the rotor can be directly observed by opening the pump cover; simple manual maintenance and cleaning; suitable for production lines with multiple batches and frequent material changes.
Screw pumps:
The rubber stator is the main wear part. The stator and screw are used in pairs, and the whole set needs to be replaced after wear. Fine impurities in the material will accelerate the aging and wear of the rubber.
Cam rotor pumps: The rotors inside the pump chamber do not contact each other, and the rotors wear almost nothing under normal operating conditions. Wear parts are concentrated in the mechanical seal, and the parts can be replaced individually, making spare parts replacement more flexible.
Cam rotor pumps: The rotors inside the pump chamber do not contact each other, and the rotors wear almost nothing under normal operating conditions. Wear parts are concentrated in the mechanical seal, and the parts can be replaced individually, making spare parts replacement more flexible.
Scenario Selection Reference
Preferably use screw pumps: For materials that are pure, free of hard particles, require pulsation-free output, and where the process demands high conveying pressure, such as high-viscosity syrups and pastes requiring high pressure.
Preferably use rotary lobe pumps: For materials containing soft particles, requiring frequent production changes, online cleaning, and steam sterilization; for conveying dairy products, fruit juices, creams, and pharmaceuticals, where ease of disassembly and maintenance is crucial.
Preferably use screw pumps: For materials that are pure, free of hard particles, require pulsation-free output, and where the process demands high conveying pressure, such as high-viscosity syrups and pastes requiring high pressure.
Preferably use rotary lobe pumps: For materials containing soft particles, requiring frequent production changes, online cleaning, and steam sterilization; for conveying dairy products, fruit juices, creams, and pharmaceuticals, where ease of disassembly and maintenance is crucial.
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