Drive Shaft Disconnector with Shear Coupler for Failure Decoupling
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Solution Overview
Problem
Existing driving mechanisms, such as gas turbine engines, fail to effectively decouple from rotating equipment during failures, leading to potential damage and debris generation.
Innovation Solution
A disconnector system comprising a shear coupler with a necked-down region and a disconnector mechanism, actuated by a meltable element and an actuator, to selectively decouple the rotatable shaft from the driving mechanism upon failure, preventing torsional overload and reducing damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the drive shaft remains connected during failure, then the driving mechanism continues to operate, but damage and debris generation occur
Solution Approach 1:
The drive shaft is segmented into multiple parts using a shear coupler with a necked-down region that can selectively fail. This segmentation allows the drive shaft to be divided into separated portions when torsional overload occurs, preventing damage propagation while maintaining operational reliability during normal conditions.
Solution Approach 2:
A disconnector mechanism acts as an intermediary between the driving mechanism and the driven equipment. This intermediary component includes a shear coupler that mediates the connection, allowing controlled separation when failure conditions are detected, thus protecting both the driving mechanism and driven equipment from damage.
2Object-affected harmful factors
If a disconnector system is added, then damage and debris are reduced, but device complexity increases
Solution Approach 1:
The disconnector system is designed to be self-activating through a meltable element that responds automatically to excessive temperature or torque conditions. The shear coupler's necked-down region self-fails at a predetermined torque threshold without requiring external control systems, reducing overall system complexity while maintaining protective functionality.
Solution Approach 2:
The system uses parameter changes in the meltable element (temperature-dependent melting) and the shear coupler (torque-dependent shearing) to trigger disconnection. These parameter-based triggers simplify the control mechanism compared to electronic sensing and actuation systems, reducing device complexity while effectively preventing damage.
3Reliability
If the shear coupler is designed with a necked-down region, then controlled separation is achieved, but manufacturing precision requirements increase
Solution Approach 1:
The necked-down region of the shear coupler is designed as a sacrificial, disposable component intended to fail under extreme conditions. This allows the use of simpler manufacturing processes for creating the necked-down geometry, as the component is replaced rather than repaired after failure, reducing the stringency of manufacturing precision requirements.
Solution Approach 2:
The necked-down region introduces a deliberate asymmetry in the shear coupler's geometry, creating a predetermined weak point. This asymmetric design concentrates stress in a specific location, ensuring controlled separation at the intended failure point. The asymmetric geometry can be efficiently manufactured using standard machining or forming processes without requiring ultra-precise tolerances.
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 system reliably separates the drive shaft from the driving mechanism, minimizing damage and debris generation during failures, ensuring safe operation and preventing secondary damage.
Implementation Method 1
a meltable element configured to melt at a threshold temperature indicative of a failure in the drive mechanism or the rotating equipment
Implementation Method 2
a shear coupler configured to shear at a predetermined torque threshold to define a first sheared portion and a second sheared portion
Data Source
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AI summary
A disconnector system for disconnecting a drive shaft of a drive mechanism from rotating equipment, upon a failure of the drive mechanism or rotating equipment, includes a disconnector mechanism having a disconnector shaft disposed in a casing and moveable relative thereto, between a first position and a second position, and a cam surface on a distal end of the arm configured to engage a slidable coupler. The movement of the disconnector shaft can be triggered by an operation of a solenoid, or by a displacement of the solenoid responsive to a melting of a meltable element.