Variable-Helix Screw Rotors for Low-Leakage Compression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing rotary screw compressors face inefficiencies due to fixed rotor profiles and diameters, leading to increased leakage and reduced performance, particularly at higher speeds and pressures.
Innovation Solution
Implementing rotors with variable profiles and helical configurations, including non-constant outer diameters and helix patterns, to enhance compression efficiency and reduce leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If fixed rotor profiles and diameters are used, then manufacturing is simpler, but leakage increases and performance decreases at higher speeds and pressures
Solution Approach 1:
The patent applies dynamics by transitioning from fixed rotor profiles to variable profiles where the outer diameter and helical configuration change along the axial length. The rotor profile evolves from a constant diameter design to a variable diameter design with conical or ogive configurations, allowing the sealing surface to adapt dynamically to pressure variations and reduce radial leakage while maintaining manufacturability through systematic profile variations.
Solution Approach 2:
The patent implements parameter changes by varying the outer diameter, helix angle, and profile geometry along the axial length of the rotor. Specifically, the outer diameter transitions from constant to variable (conical or ogive), and the helical configuration changes from fixed to variable pitch, optimizing the sealing characteristics to reduce leakage at higher speeds and pressures while remaining manufacturable.
2Ease of manufacture
If fixed rotor profiles are used, then manufacturing is easier, but compression efficiency is reduced
Solution Approach 1:
The patent applies dynamics by making the rotor profile variable rather than fixed, allowing the compression characteristics to adapt during operation. The variable profile with changing outer diameter and helical configuration enables optimized cell formation and fluid compression, improving compression efficiency while maintaining manufacturability through systematic design approaches.
Solution Approach 2:
The patent implements parameter changes by varying multiple geometric parameters including outer diameter, helix angle, and profile shape along the axial length. These changes optimize the compression process by creating favorable pressure distributions and reducing leakage, thereby improving compression efficiency without excessive manufacturing complexity.
3Loss of energy
If variable profiles and helical configurations are implemented, then leakage is reduced and efficiency is improved, but rotor design and manufacturing complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the rotor into distinct sections with different profile characteristics. The rotor is segmented into zones with varying outer diameters and helical configurations, allowing each section to be optimized for specific functional requirements while maintaining overall manufacturability through modular design approaches.
Solution Approach 2:
The patent implements local quality by applying different profile characteristics to different sections of the rotor. Specifically, the outer diameter and helix angle vary locally along the axial length, with conical or ogive configurations in specific zones to optimize sealing and compression performance at critical locations while maintaining simpler geometries where appropriate.
4Speed
If variable profiles and helical configurations are implemented, then compression speed is increased, but manufacturing precision requirements increase
Solution Approach 1:
The patent implements parameter changes by varying the outer diameter and helical configuration in a systematic manner that balances performance with manufacturability. The conical and ogive profiles use well-defined geometric relationships that can be manufactured with standard precision tolerances while achieving the desired compression speed enhancement through optimized cell formation and reduced leakage.
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
A screw compressor or expander is provided, comprising a female rotor (414) including a first section having a right-hand first groove and a second section having a left-hand second groove. The first groove has a first variable helix, the second groove has a second variable helix, and the female rotor has a first variable profile and a first variable outer diameter. The screw compressor or expander further comprises a male rotor (410) including a third section having a left-hand first lobe and a fourth section having a right-hand second lobe. The first lobe has a third variable helix, the second lobe has a fourth variable helix, and the male rotor has a second variable profile and a second variable outer diameter.