Lightweight Gearbox Locking Assembly for Vibration-Resistant Preload
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current gearbox gear train components in aircraft engines face loosening due to destructive vibrations, requiring time-consuming assembly and maintenance, and existing solutions often need three pieces of hardware for proper function, which can lose preload over time.
Innovation Solution
A two-piece drive mechanism featuring a nut washer with tangs and a serrated lock nut that provides double locking safety, preloading and locking components in a rotating environment without the need for periodic inspections, using a serrated deformation locking design and tangs to prevent rotation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional locking hardware (three-piece assembly) is used to prevent loosening, then reliability against vibration loosening is improved, but device complexity increases and assembly time increases
Solution Approach 1:
The patent combines the locking washer and lock nut into a single integrated two-piece assembly. The locking mechanism incorporates both the washer function and nut function in one unit, eliminating the need for separate locking washers and reducing assembly complexity while maintaining vibration resistance through the integrated serrated design and deformation locking mechanism
Solution Approach 2:
The locking assembly uses self-locking features including serrated edges that deform into the mating surface and tangs that engage with grooves, creating automatic mechanical interference that prevents loosening without requiring additional locking elements or periodic tightening, allowing the assembly to maintain its own preload under vibration
2Reliability
If traditional locking hardware is used to prevent loosening, then reliability against vibration loosening is improved, but assembly time increases
Solution Approach 1:
The integrated two-piece locking assembly reduces the number of components to be handled and installed, streamlining the assembly process while maintaining reliable vibration resistance through the built-in deformation locking and tang-groove engagement mechanisms
Solution Approach 2:
The self-locking features automatically engage during assembly without requiring additional locking steps or periodic maintenance, reducing assembly time and eliminating the need for separate locking operations while ensuring continuous vibration resistance
3Ease of manufacture
If existing retention hardware is reused, then assembly cost is reduced, but reliability decreases due to preload loss
Solution Approach 1:
The locking assembly incorporates a deformable washer face and serrated edges designed for single-use application. These features undergo permanent deformation during installation to create the locking effect, meaning the locking mechanism is effective for one assembly event and provides reliable preload maintenance without requiring reuse of the same locking features
Solution Approach 2:
The tangs are pre-formed to engage with grooves in the mating component, and the serrated edges are pre-configured to deform into the mating surface during assembly, creating immediate mechanical interference and preload maintenance upon installation without requiring subsequent adjustments or inspections
4Ease of operation
If conventional locking methods are used, then initial assembly is simplified, but periodic inspections are required to maintain reliability
Solution Approach 1:
The deformation locking mechanism and tang-groove engagement create self-verifying mechanical interference that maintains preload automatically throughout operation, eliminating the need for periodic visual inspections or torque checks while keeping the assembly simple to install
Solution Approach 2:
The locking features are designed to create permanent deformation and mechanical interference during initial assembly that maintains reliability throughout the component's service life without requiring ongoing inspection or maintenance, ensuring torque maintenance through the built-in deformation locking mechanism
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 mechanism effectively maintains required torque throughout the drive system's operating life, eliminating the need for locking wires or screws and maintaining assembly balance without requiring periodic visual inspections.
Implementation Method 1
As the installation torque is applied, the face of the nut washer deforms and becomes compliant to the serration form and offers mechanical resistance to un-torquing the lock nut
Implementation Method 2
A nut washer coupled of the locking nut assembly includes a plurality of tangs that are operatively disposed within grooves disposed longitudinally in threads of the gear shaft to prevent rotation of the nut washer with respect to the gear shaft
Data Source
AI summary
A lock nut and tang washer mechanism preloads and locks components in a rotating environment. A drive system mechanism preloads and locks the device in a rotating environment and provides a double locking safety requirement needed in most aircraft for applications operating in an enclosed environment. The mechanism holds a required torque for the duration of the drive system operating life without the need for periodic visual inspections.