Single-Lobe and Double-Lobe Rotor Profile Design for Smooth Meshing

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Solution Overview

Problem

Existing rotor mechanisms suffer from discontinuous curves at segment joints, leading to incomplete meshing, noise, vibration, and reduced durability during periodic expansion and compression operations, due to inappropriate intermeshing.

Innovation Solution

Designing single-lobe and double-lobe rotors with specific curve portions, including arcs and lines, to ensure smooth intermeshing and conjugation, using equations to define radii and centers, resulting in a defined rotor and conjugate rotor that provide higher compression ratios and larger discharge capacities, reducing leakage, noise, and vibration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional rotor mechanisms are used with segmented curves, then the structure is simpler to manufacture, but the curves are discontinuous at segment joints causing incomplete meshing, noise, and vibration

Engineering Contradiction:

Improvemeshing qualityVSAvoidnoise and vibration

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent applies curvature principle by replacing straight line segments with continuous curved profiles (circular arcs and transition curves) in the rotor lobes. The rotor profile is constructed using multiple circular arcs with different radii connected through smooth transition curves, ensuring continuous curvature without sharp corners or discontinuities. This curved geometry enables complete and smooth meshing between rotor and stator teeth, eliminating the discontinuous curves at segment joints that cause noise and vibration in traditional segmented rotor designs.

Inventive Principle:

Principle #14Spheroidality (Curvature)

2Productivity

If traditional rotor designs are used, then the manufacturing process is simpler, but the compression ratio and discharge capacity are lower

Engineering Contradiction:

Improvedischarge capacityVSAvoidmanufacturing complexity

Core Design Contradiction:

ProductivityVSEase of manufacture

Solution Approach 1:

The patent applies segmentation principle by dividing the rotor lobe profile into multiple distinct curve segments (circular arcs and transition curves), each defined by specific geometric parameters such as radius, center coordinates, and arc angles. This segmented approach allows precise control over the rotor geometry to optimize compression ratio and discharge capacity, while each segment can be independently calculated and manufactured, making the complex overall shape feasible for production.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies parameter changes principle by systematically varying geometric parameters (radii of circular arcs, positions of centers, arc angles, and transition curve parameters) to optimize the rotor profile for maximum discharge capacity and compression ratio. Different parameter sets are used to define different curve segments, allowing the rotor geometry to be tuned for optimal performance while maintaining manufacturability through defined parameter ranges and relationships.

Inventive Principle:

Principle #35Parameter changes

3Productivity

If traditional rotor designs are used, then the structure is simpler, but leakage increases reducing operational efficiency

Engineering Contradiction:

Improveoperational efficiencyVSAvoidleakage

Core Design Contradiction:

ProductivityVSLoss of substance

Solution Approach 1:

The continuous curved profile with smooth transitions eliminates gaps and discontinuities in the rotor-stator meshing, creating effective sealing between adjacent lobes and preventing gas leakage. The curved geometry ensures that rotor and stator teeth engage completely throughout the rotation cycle, maintaining high sealing ability and reducing leakage losses that would reduce operational efficiency.

Inventive Principle:

Principle #14Spheroidality (Curvature)

4Duration of action of stationary object

If rotors with discontinuous curves are used, then the design is simpler, but wear increases reducing durability

Engineering Contradiction:

ImprovedurabilityVSAvoidwear resistance

Core Design Contradiction:

Duration of action of stationary objectVSStrength

Solution Approach 1:

The continuous curved profile with smooth transitions eliminates sharp corners and discontinuous joints that act as stress concentration points and accelerate wear. The smooth curved geometry distributes contact stresses more uniformly across the rotor-stator interface, reducing localized wear and extending the operational life and durability of the rotor mechanism.

Inventive Principle:

Principle #14Spheroidality (Curvature)

Data Source

PatentUS7594323B2Methods for designing single-lobe and double-lobe rotors

Publication Date: 2009.09.29 GPOUER

AI summary

The present invention provides methods for designing single-lobe or double-lobe rotors which enable a defined rotor and a conjugate rotor intermeshing and conjugating to each other and by parameterized sets to generate curve portions of half two lobes of the defined rotor including a curve E, an arc A, an arc B, an arc F, an arc C, an arc G and a horizontal line Y. The main feature is that a radius of the arc C being defined by following equation:rC=x+rF=⁢x⁢⁢sin⁢⁢β+D2⁢⇒x=(D/2)-rF1-sin⁢⁢β;⁢rC=(D/2)-rF1-sin⁢⁢β+rFin which rF is two times pitch circle radius(Rp) of the defined rotor deducting the maximum radius(R) of the defined rotor(rF=2 Rp−R), and a center of the arc C is located in a straight extension direction from a center of the defined rotor and an end point of an arc F.