Propeller Shaft Damper Retention Lip for Axial Impact Resistance
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Solution Overview
Problem
Existing methods for attaching tuned dampers to propeller shaft yokes are insufficient in preventing dislodgment due to axial loads, leading to potential separation and underbody noise issues.
Innovation Solution
Incorporating a retention lip extending radially downwardly from the second damper ring, which is axially spaced from the mounting hub, provides a mechanical shield that limits axial displacement and prevents dislodging from axial forces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If adhesive bonding is used to secure the tuned damper to the propeller shaft yoke, then the retention force increases and slippage is reduced, but manufacturing complexity and cost increase due to additional cleaning, adhesive application, and curing steps
Solution Approach 1:
The patent replaces the chemical adhesive bonding system with a mechanical retention system using a retention lip and interference fit. The retention lip extends radially inward to engage with a counterbore in the yoke, creating a mechanical interlock that eliminates the need for adhesive application, cleaning, and curing steps while maintaining strong retention forces.
Solution Approach 2:
The tuned damper is divided into functional segments: the inertia ring, the elastomeric damping ring, and the retention lip structure. This segmentation allows each component to perform its specific function while being assembled through a simplified process that does not require adhesive bonding of the entire assembly.
2Ease of manufacture
If radial compression of the elastomeric damping ring is used to secure the tuned damper, then assembly is simplified, but the retention force is insufficient and the damper can be dislodged by axial impacts
Solution Approach 1:
The patent merges two retention mechanisms into a single integrated solution: the radial compression of the elastomeric damping ring is combined with the axial retention provided by the retention lip engaging the counterbore. This combination maintains the simplicity of radial compression assembly while adding the reliability of axial impact resistance through the mechanical interlock.
Solution Approach 2:
The retention system utilizes composite action between the rigid retention lip structure and the flexible elastomeric damping ring. The rigid lip provides axial retention through mechanical interlocking, while the elastomeric ring provides radial compression and vibration damping, creating a composite retention system that addresses both assembly simplicity and retention reliability.
3Stability of the object's composition
If the retention lip is positioned close to the mounting hub, then axial displacement is limited, but contaminant buildup may interfere with the damper's damping function
Solution Approach 1:
The patent applies local quality by creating a specific geometric configuration of the retention lip and counterbore assembly that provides axial retention while maintaining clearance from the mounting hub. The retention lip is positioned at an optimal distance that allows contaminant clearance while still effectively limiting axial displacement, thereby addressing both stability and contaminant protection locally at the retention interface.
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 retention lip effectively enhances the robustness of the tuned damper by preventing disassembly induced by external forces, while also minimizing the risk of contaminant buildup that could interfere with the damper's function.
Implementation Method 1
Friction between the elastomeric damper ring and the metal components may be reduced temporarily for assembly using a lubricant or emulsifier that evaporates or absorbs into the elastomer once assembly is complete. However, reliance on frictional forces from radial compression of the elastomeric damper ring as the only method of securing the elastomer ring and the inertia mass ring to the propeller shaft yoke provides the potential for the tuned damper to be dislodged
Implementation Method 2
tuned dampers are commonly mounted on a machined outer surface or mounting hub of the propeller shaft yokes, and include an elastomeric or rubber damping ring, and a rigid inertia mass ring to create a tuned damper that absorbs torsional or radial vibration energy present in the driveline system
Implementation Method 3
Tuned dampers may be disposed at various locations on propeller shafts due to a number of factors, such as clearance of other surrounding driveline components throughout the operational range of the automobile. Some propeller shafts are configured in more than one piece (i.e., multi-piece), due to driveline configurations, among other reasons. These single or multi-piece propeller shafts, particularly when utilized in truck, sport utility vehicles (SUV) and sports car applications, are often configured with a tuned damper commonly mounted to propeller shaft yokes
Data Source
AI summary
A propeller shaft assembly includes a propeller shaft extending along an axis between a first and second shaft end. A propeller shaft yoke is operably connected to one of the first or second shaft ends and includes a body presenting a mounting surface extending circumferentially about the axis. A tuned damper extends radially outwardly from the mounting surface and includes a first damper ring disposed in abutting and encircling relationship with the mounting surface and a second damper ring disposed in abutting and encircling relationship with the first damper ring. The tuned damper includes a retention lip extending radially downwardly from the second damper ring in axially spaced relationship with the mounting hub by an axial spacing distance D for protecting the tuned damper from axial impact forces and improving the robustness of the tuned damper mounted on the mounting surface.