Rotary Coupling Member Structure for Misalignment and Fatigue

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Solution Overview

Problem

Conventional couplings for rotating equipment have limited flexibility, leading to high stresses and potential fatigue fractures when accommodating misalignment, and may require redesign if misalignment increases, resulting in costly failures.

Innovation Solution

The coupling members are designed as a unitary body with a first and second coupling element and a hub, featuring a stepped construction with thick, thin, and linking portions, and material voids, optimized for reduced weight and increased flexibility without increasing fabrication costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional couplings are used to accommodate misalignment, then torque transmission is enabled, but high stresses and fatigue fractures occur due to limited flexibility

Engineering Contradiction:

Improvemisalignment accommodationVSAvoidfatigue resistance

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The coupling member is divided into multiple coupling elements (first coupling element, second coupling element, etc.) connected by spacers. Each coupling element can independently deflect to accommodate misalignment, distributing the stress across multiple segments rather than concentrating it in a single rigid structure. This segmentation enables the coupling to adapt to misalignment while maintaining reliability through stress distribution.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The coupling member transitions from a rigid structure to a dynamic one where coupling elements can deflect and move relative to each other. The spacers allow controlled movement and deflection of coupling elements, enabling the system to dynamically adapt to changing misalignment conditions during operation, thereby reducing fatigue stresses and improving reliability.

Inventive Principle:

Principle #15Dynamics

2Adaptability or versatility

If additional flexible elements are incorporated to increase misalignment tolerance, then flexibility improves, but weight and fabrication cost increase

Engineering Contradiction:

Improvemisalignment toleranceVSAvoidcoupling weight

Core Design Contradiction:

Adaptability or versatilityVSWeight of moving object

Solution Approach 1:

The coupling elements are designed with varying thicknesses (thick portions, thin portions, linking portions) to create flexible regions that can deflect without adding significant weight. The thin portions and linking portions act as flexible hinges that enable misalignment accommodation while maintaining low weight, avoiding the need for heavy additional flexible elements.

Inventive Principle:

Principle #30Flexible shells and thin films

Solution Approach 2:

Different portions of the coupling elements have different thicknesses and material properties optimized for their specific functions. Thick portions provide structural strength where needed, while thin portions provide flexibility for deflection. This local variation in quality allows the coupling to achieve high misalignment tolerance without uniformly increasing weight throughout the entire structure.

Inventive Principle:

Principle #3Local quality

3Strength

If coupling elements occupy full circular area for strength, then structural integrity is maintained, but weight increases

Engineering Contradiction:

Improvestructural integrityVSAvoidcoupling element weight

Core Design Contradiction:

StrengthVSWeight of moving object

Solution Approach 1:

Material is removed from the coupling elements to create voids within the circular area, extracting unnecessary material that does not contribute to structural integrity. The remaining material is strategically positioned to maintain strength while reducing weight, creating an optimized structure that preserves essential load-bearing pathways while eliminating excess weight.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The coupling elements incorporate voids and hollow regions within their structure, creating a porous-like configuration that reduces weight while maintaining structural integrity. The strategic placement of voids allows the coupling elements to retain sufficient material for strength while achieving weight reduction, optimizing the strength-to-weight ratio.

Inventive Principle:

Principle #31Porous materials

Data Source

PatentUS12305720B2Coupling members that join first and second rotary members

Publication Date: 2025.05.20 JOHN CRANK UK

AI summary

Coupling members to join two rotary members, such that the coupling members (300) include a unitary body having a first coupling element (302), a second coupling element (304), and a hub (306), wherein the unitary body forms a single piece with the hub (306) extending between and connecting the first coupling element (302) to the second coupling element (304). The first coupling element (302) defines a first plane, the second coupling element (304) defines a second plane with the first and second planes being parallel, and the hub (306) defines a hub axis normal to the first and second planes. Each of the first and second coupling elements (302, 304) comprises a plurality of connection elements (308, 310) arranged about a respective circumference having a respective radius extending from the hub axis, wherein a material of the respective coupling element in a respective circle and in a respective plane is less than the area of the circle. The material forming the first and second coupling elements (302, 304) is arranged in a respective circumscribing circle over an area less than the total area defined by the circle in the respective plane.