Shaft Shear Section With Anti-Flail Containment Cage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current power transmission shafts designed to fail at a specific point during torsional overloads often have containment devices located away from the necked-down region, which may not effectively contain a flailing shaft caused by torsional overload, leading to potential damage to nearby components.
Innovation Solution
A shear section with a coupling flange and shear bolts featuring a necked-down region and an anti-flail feature, where the shear bolts disconnect under torsional overload, and an anti-flail bearing and wear ring prevent radial displacement and frictional damage, respectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a containment device is placed away from the necked-down region to contain non-torsional failures, then it can protect against non-torsional load failures, but it fails to contain flailing shaft sections during torsional overload failures
Solution Approach 1:
The patent combines the containment function with the shear section by integrating a containment cage that surrounds the necked-down region. This merging ensures that when torsional overload causes the shaft to fail at the necked-down region, the containment cage is positioned exactly where needed to capture the flailing shaft section, resolving the contradiction between containment effectiveness and positioning complexity.
Solution Approach 2:
The containment cage is pre-positioned around the necked-down region before failure occurs. This preliminary positioning ensures that when torsional overload happens, the containment structure is already in place to immediately capture the shaft section, eliminating the need for complex real-time positioning adjustments.
2Strength
If shear bolts with necked-down regions are used to enable controlled failure during torsional overload, then the shaft can disconnect to prevent damage to major components, but the disconnected shaft section may flail and damage surrounding components
Solution Approach 1:
The containment cage is designed to preemptively counteract the harmful radial displacement that occurs when shear bolts fail. By surrounding the necked-down region with the cage before failure, the system prepares the counter-measure needed to prevent the flailing shaft from damaging surrounding components, thus applying preliminary anti-action to the potential harm.
Solution Approach 2:
The patent converts the potentially harmful flailing motion of the disconnected shaft into a controlled movement within the containment cage. The cage guides the shaft's radial displacement, transforming the harmful uncontrolled flailing into a beneficial contained motion that protects surrounding components while still allowing the shaft to disconnect during overload.
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 shear section effectively disconnects the shaft from the coupling flange during torsional overload, containing radial displacement and preventing damage to surrounding components, while allowing continuous normal torque transmission.
Implementation Method 1
Each of the plurality of fasteners includes a shank region and a reduced thickness portion circumscribing the shank region
Implementation Method 2
an anti-flail bearing and wear ring prevent radial displacement and frictional damage, respectively
Data Source
Figure 1~2
Figure 3~4
AI summary
A shear section (18) for a rotating arrangement includes an axially-extending shaft (12) having a connection flange and a coupling flange (20) adjacent the connection flange. The coupling flange (20) includes an annular shoulder portion (22) and an elongated neck portion (24) extending axially away from the shoulder portion (22) and disposed concentrically within the shaft (12). The shear section (18) further includes a plurality of fasteners extending axially through the shoulder portion (22) and the connection flange, and securing the shaft (12) to the coupling flange (20). Each of the plurality of fasteners includes a shank region (42) and a reduced thickness portion circumscribing the shank region (42).