Keyed Mechanical Connector for High-Torque Load Transfer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing mechanical connectors, such as the Merlin™ family connectors, face limitations in handling high torsional loads and fatigue, with limited torsional load capacities and difficulty in accurate control, particularly in offshore engineering applications where high torsional and bending loads are prevalent.
Innovation Solution
The introduction of structural features like dog-clutch teeth, fitted pins, splines, and interlocked thread systems, combined with modifications in connector shapes and the use of assembly/disassembly fluids that solidify at operational temperatures, enhance torsional load transfer and fatigue resistance while maintaining high bending load capacities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If traditional friction-based torque transfer is used in Merlin™ family connectors, then the connector design is simple, but the torsional load capacity is limited and difficult to control accurately
Solution Approach 1:
The connector is divided into distinct functional elements: friction-based axial load transfer through threaded engagement, and separate positive torque transfer mechanisms (keys, splines, or dog-clutch teeth) that engage specifically for torsional loads. This segmentation allows each mechanism to be optimized independently, achieving high torsional capacity without compromising the simplicity of the overall friction-based design.
Solution Approach 2:
Positive torque transfer elements (keys, splines, or dog-clutch teeth) act as intermediaries between the pin and box, providing controlled torque transfer paths. These elements mediate the torque transfer process, enabling accurate control of torsional load capacity while maintaining the simple friction-based axial connection of traditional Merlin™ connectors.
2Strength
If variable outside stress diameters and inside stress diameters are implemented, then torsional load capacity is improved, but manufacturing complexity increases
Solution Approach 1:
The variable diameter profile is segmented into distinct zones: constant diameter sections for simple manufacturing, and tapered sections for optimized stress distribution. This segmentation allows standard machining operations for the constant sections while applying more complex tapering only where structurally necessary, balancing manufacturing precision requirements with torsional strength improvements.
Solution Approach 2:
Variable diameters are applied locally at specific positions along the connector length rather than uniformly throughout. The tapered sections with varying diameters are positioned at locations experiencing highest torsional stresses, while other sections maintain constant diameters for easier manufacturing. This local application of quality variations optimizes strength where needed without unnecessarily increasing overall manufacturing complexity.
3Reliability
If assembly/disassembly fluids that solidify at operational temperatures are used, then leak resistance is improved, but the device complexity increases
Solution Approach 1:
The assembly/disassembly fluid utilizes phase transition properties, remaining liquid at assembly temperatures for easy injection and operation, then solidifying at operational temperatures to provide leak resistance. This phase change behavior eliminates the need for additional mechanical sealing components, improving reliability without significantly increasing device complexity.
Solution Approach 2:
The fluid provides self-service sealing functionality by automatically transitioning from liquid to solid state at operational temperatures, creating its own seal without requiring external actuation or additional sealing mechanisms. This self-service approach improves leak resistance while maintaining the relative simplicity of the connector design.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The novel connectors achieve improved torsional and bending fatigue life, enabling efficient transfer of high torque loads and maintaining structural integrity under demanding offshore conditions, with reduced design pressures and smaller sizes, while also offering weight control and leak resistance.
Implementation Method 1
the use of assembly/disassembly fluids that solidify at operational temperatures
Implementation Method 2
a thread (zero pitch angle for background art connectors) on substantially matching frustoconical surfaces
Data Source
AI summary
This invention builds up on technical features and on the industry experience with the use of Merlin™ family connectors. In addition to friction, structural means utilized to transfer high torsional loads include keys and may also include: interlocked thread systems, shear pins, dog-clutch teeth and splines, all used in isolation or in arbitrary combinations. Static and fatigue bending load capacities of the connectors remain high, while the axial load capacities may or may not be high, depending on the design requirements. Connectors according to this invention can be built as new, carefully optimized designs. In some cases upgrading existing Merlin™ family connector designs to increase they torque transfer capacities may be also feasible.