Fairlead Counterweight Mechanism for Anchoring Chain Jamming
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing anchoring systems for floating oil-well exploitation platforms and FPSO vessels face issues with fairlead components becoming stuck due to jamming and wear, leading to unreliable operation of anchor chains, particularly in submerged hydraulic cylinders and control cables.
Innovation Solution
A fairlead design featuring a counterweight mechanism that maintains the grip jaw in an active position and automatically returns to it, using a counterweight that moves between low and high positions to accumulate mechanical potential energy, ensuring reliable operation and reducing wear-related failures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If the grip jaw and operating means are permanently immersed in water, then the fairlead can function continuously for anchoring, but the components become stuck due to jamming and wearing phenomena
Solution Approach 1:
The patent introduces a counterweight mechanism that automatically returns the grip jaw to the active locking position after chain re-tensioning. The counterweight compensates for the forces causing jamming by providing a restoring moment, ensuring the jaw reliably returns to its functional position despite prolonged immersion and wear conditions.
2Reliability
If the grip jaw is held in active position by mechanical means, then the anchor chain is securely locked, but the mechanism becomes complex and prone to wear
Solution Approach 1:
The counterweight mechanism replaces complex active holding systems with a passive gravitational balancing system. The counterweight automatically maintains the grip jaw in the active position through gravitational force, eliminating the need for additional active holding mechanisms and reducing overall system complexity while maintaining reliability.
Solution Approach 2:
The counterweight system is self-regulating and requires no external control or additional active components to maintain the locking position. The gravitational force automatically compensates for wear and maintains the jaw in the active position, making the system self-servicing and reducing mechanical complexity.
3Ease of operation
If hydraulic cylinders and control cables are used to operate the grip jaw, then the jaw can be actuated reliably, but the components become stuck due to jamming and wearing phenomena in submerged conditions
Solution Approach 1:
The counterweight mechanism provides a mechanical advantage that reduces the actuation force required from the hydraulic cylinder. By balancing the gravitational moment, the system reduces the operational load on submerged components, minimizing wear and jamming while maintaining reliable jaw actuation capability.
Solution Approach 2:
The system operates in periodic cycles: the hydraulic cylinder actuates the jaw to the inactive position for re-tensioning, then releases to allow the counterweight to automatically return the jaw to the active position. This periodic operation reduces continuous stress on submerged components, minimizing wear and jamming phenomena.
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 counterweight mechanism enhances the reliability of the fairlead by maintaining the grip jaw in an active position, reducing the likelihood of jamming and wear, thereby ensuring consistent and secure operation of the anchor chains, even after re-tensioning.
Implementation Method 1
an inert mass, referred to as counterweight, which is movably coupled to said jaws and which is operable in a height direction between a low position and a high position corresponding to said active position and said inactive position of said jaws, respectively, so as to operate and to tend to hold said jaws in said active position
Data Source
AI summary
A fairlead for guiding an anchor chain, intended to equip a ground anchor system for a floating platform, includes a bending structure for guiding a direction change of the associated anchor chain, and a locking structure that includes a grip jaw consisting of two jaws associated with operating elements for rotatably moving the jaws in opposite directions. The operating elements include: (a) an inert mass, referred to as “counterweight”, which is movably coupled to the jaws and which is height-adjustable between a low position and a high position corresponding to an active position and an inactive position of the jaws, respectively, so as to operate and tend to maintain the jaws in the active position, and (b) an actuator driven by control elements, for operating the jaws from the active position to the inactive position and for operating the counterweight from the low position to the high position.