Redundant Coupling Arrangement with Spline Backup
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Solution Overview
Problem
Conventional flexible couplings lack redundancy in torque transmission, which can lead to failure when the torque applied exceeds the torque-carrying capability of the diaphragms, necessitating a solution that ensures continuous torque transfer even under overload conditions.
Innovation Solution
A redundant coupling arrangement featuring a primary torque transmitting arrangement with a flexible diaphragm section and a secondary torque transmitting arrangement with a spherical body and collar, where external splines engage internal splines only upon failure or overload, allowing torque to be transmitted through either or both arrangements, providing three operating modes: exclusive primary, exclusive secondary, and split torque transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single torque transmitting arrangement with flexible diaphragms is used, then the coupling can accommodate shaft misalignment and transmit torque under normal conditions, but the coupling lacks redundancy and fails when torque exceeds the diaphragms' torque-carrying capability
Solution Approach 1:
The torque transmitting function is segmented into two independent arrangements: a primary flexible diaphragm arrangement and a secondary rigid spline arrangement. Each arrangement can independently transmit torque, providing redundancy. The primary arrangement handles normal operation while the secondary arrangement serves as backup, eliminating the single point of failure in conventional single-arrangement couplings.
Solution Approach 2:
The secondary torque transmitting arrangement with splines is pre-configured as a backup system that remains dormant during normal operation. When the primary flexible diaphragm arrangement fails or becomes overloaded, the secondary arrangement automatically engages to prevent complete system failure, providing beforehand protection against torque overload and diaphragm failure.
2Reliability
If the secondary torque transmitting arrangement is designed to engage only upon failure of the primary arrangement, then wear is reduced and reliability is improved, but the control mechanism for selective engagement becomes more complex
Solution Approach 1:
The secondary torque transmitting arrangement is designed to self-engage automatically when the primary arrangement fails. The splines are positioned such that they remain disengaged during normal operation but automatically engage when the flexible diaphragms fail to transmit torque, eliminating the need for external sensors, actuators, or control systems to detect failure and initiate backup operation.
Solution Approach 2:
The primary and secondary torque transmitting arrangements are positioned asymmetrically with different radial locations and engagement characteristics. The secondary arrangement's splines are configured to be radially inward and engage only under specific failure conditions, creating an asymmetric geometry that enables automatic selective engagement without complex control mechanisms.
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 redundant coupling arrangement ensures continuous torque transmission by engaging the secondary load path only when necessary, reducing wear and providing overload protection, thereby enhancing the reliability and service life of the coupling.
Implementation Method 1
The diaphragms are typically configured to accommodate shaft misalignments while transferring torque without over-stressing the material forming the diaphragms, typically by varying the diaphragm profile. The profile ensures that stress within the diaphragm remains below the yield strength of the diaphragm material while allowing diaphragm bending to accommodate misalignment.
Implementation Method 2
A plurality of external splines are disposed on an outer surface of the spherical body. The external splines can have a crown. The external splines can be spherical splines. The external splines can have a spherical drive surface. Each of the external splines can be received within an internal spline.
Data Source
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AI summary
A flexible diaphragm coupling that includes a primary torque path and a secondary torque path. The secondary torque path includes a crowned or spherical spline assembly (152) and provides additional capability during transient overtorque of the primary torque path or acts as the primary torque path in the unlikely event of diaphragm failure.