Design Requirements for Screw Compressors

Core rotor profile design

The rotor profile is a core element of screw compressors, directly determining the equipment’s volumetric efficiency and operational stability. During the design process, the tooth geometry must undergo rigorous mathematical modeling and optimization.

• Meshing Characteristic Optimization: Ensure that the contact line length between the male and female rotors is minimized during meshing, while keeping the leakage triangle area within an acceptable range.
• Line continuity of the hull form: Ensures smooth transitions on the tooth surfaces, prevents machining interference and stress concentrations, and enhances the overall stiffness of the rotor.

Precision Clearance and Tolerance Control

Screw compressors feature multiple critical clearances within their internal components; a well‑balanced clearance design is essential for optimizing both compression efficiency and mechanical reliability. During the design process, it is necessary to comprehensively account for thermal expansion, manufacturing tolerances, and assembly errors.

• Rotor clearanceThe clearance between the male and female rotors must be precisely calculated based on operating temperature and pressure differential to prevent seizing at elevated temperatures.
• Housing clearanceThe clearance between the rotor’s outer diameter and the inner wall of the housing must balance internal leakage control with the rotor’s radial runout tolerance.
• End clearanceThe clearance between the rotor end face and the bearing housing end face must be strictly controlled to minimize axial leakage from the high-pressure side to the low-pressure side.

Lubrication, Sealing, and Cooling Systems

An efficient lubrication and cooling system can effectively reduce friction losses, control exhaust temperatures, and extend equipment service life.

• Fuel Injection System Design: Precisely calculate the fuel injection quantity and injection timing to ensure adequate cooling and sealing of the rotor meshing zone.
• Oil-gas separation: Design an efficient oil–gas separation structure to reduce the oil content in the exhaust gas and meet the requirements of downstream processes.
• Cooling Match: Match the heat exchange area of the oil cooler or water cooler appropriately based on the compressed‑heat load.

Bearing Selection and Shaft Seal Design

The reliability of bearings and shaft seal assemblies directly determines the compressor’s mean time between failures.

• Bearing assembly: Appropriately configure the radial and thrust bearings to ensure that the rotor maintains precise axial and radial positioning under complex aerodynamic and gear‑transmission loads.
• Shaft seal structureIt employs a reliable mechanical seal or labyrinth seal design to prevent lubricating oil from leaking into the compression chamber while also ensuring that compressed gas does not escape into the surrounding environment.

Vibration and Noise Control

Reducing vibration and noise is a critical design consideration for enhancing equipment performance and meeting environmental protection requirements.

• Dynamic balancing requirementsThe rotor assembly must undergo high-precision dynamic balancing to eliminate centrifugal force imbalance during rotation.
• Structural stiffness: Enhance the structural rigidity of the housing and end covers to prevent resonance under excitation forces.
• Airflow pulsationOptimize the position and shape of the intake and exhaust ports to smooth pressure transitions and reduce aerodynamic noise caused by airflow pulsations.