Single Screw Compressor Main Rotor Asymmetric Wrap Angle Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Single screw compressors face limitations in achieving high output due to the constraint of the wrap angle of the main rotor, which affects the mounting and operation of gate rotors, leading to reduced compressor efficiency and capacity.
Innovation Solution
The main rotor is designed with a combination of first and second wrap angles, where the first wrap angle is greater than 180 degrees and the second wrap angle is less than 180 degrees, allowing for increased output while maintaining assembly compatibility by creating an enlarged groove opening for gate rotor positioning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the wrap angle of the main rotor is increased to improve compressor output, then the compressor output increases, but the gate rotor cannot be properly mounted due to spatial interference
Solution Approach 1:
The main rotor is segmented into multiple lands (first land, second land, third land) with different wrap angles. The first land has a wrap angle greater than 180 degrees to increase compressor output, while the second and third lands have wrap angles less than 180 degrees to provide clearance for gate rotor mounting. This segmentation allows both contradictory requirements to be satisfied simultaneously.
Solution Approach 2:
Different portions of the main rotor are given different local properties (different wrap angles). Specifically, the first land portion has a larger wrap angle for high output performance, while the second and third land portions have smaller wrap angles to accommodate gate rotor assembly. This local differentiation resolves the conflict between overall performance and local assembly requirements.
2Productivity
If the wrap angle is increased beyond 180 degrees to achieve high output, then compressor capacity increases, but assembly compatibility is lost
Solution Approach 1:
The rotor circumference is divided into multiple lands with different wrap angle characteristics. This segmentation enables the rotor to simultaneously provide the >180 degree wrap angle needed for high capacity and the <180 degree wrap angle sections needed for proper gate rotor positioning and assembly compatibility.
Solution Approach 2:
The main rotor employs asymmetric land design where not all lands have the same wrap angle. The first land is asymmetric with respect to the second and third lands in terms of wrap angle measurement, allowing optimization for both capacity and assembly requirements in different angular positions.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
In one aspect, a single screw compressor is disclosed. The compressor, in at least some embodiments, includes: a housing (12) including a cylindrical bore (24); a pair of gate rotors (16,18) mounted for rotation in the housing (12), each gate rotor (16,18) having a plurality of gear teeth (32); and a main rotor (14') rotatably mounted in the bore (32) and having a plurality of grooves (25,25'), a plurality of lands (15,15'), an additional groove (25'), and an additional land (15'); wherein the plurality of lands (15,15') of the main rotor (14') comprises a first wrap angle and the additional land (15') comprises a second wrap angle, and the second wrap angle is distinct and different from the first wrap angle. In other aspects, a method of assembling a gate rotor (16,18) in relation to a main rotor (14') that is positioned within a single screw gas compressor configured for high output, and a main rotor device for use with a single screw compressor configured for high output are also disclosed.