Propeller Shaft Locking Device for Collision Load Reduction
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Solution Overview
Problem
Existing propeller shafts face limitations in reducing collapse loads during collisions, with current swaging structures only achieving a 20% reduction in collapse loads, necessitating a new structure to enhance impact performance.
Innovation Solution
A propeller shaft with a locking device that includes a hollow case with axially movable switches and radially translating stoppers, allowing the interior and exterior hubs to decouple and slide relative to each other during collisions, thereby reducing the collapse load by minimizing resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a swaging structure is applied to reduce collapse load during collision, then the collapse load is reduced by about 20%, but further improvements are limited by the processing and strength of the swaging structure
Solution Approach 1:
The locking device is divided into multiple functional components: a locking protrusion on the interior hub, a corresponding locking groove on the exterior hub, and a release mechanism. This segmentation allows each component to be optimized independently while working together to provide superior collision resistance compared to a monolithic swaging structure.
Solution Approach 2:
The locking device acts as an intermediary mechanism between the interior and exterior hubs, providing a controlled locking and release function. This intermediary structure enables precise control over the collision response, overcoming the limitations of direct swaging structures that cannot be dynamically adjusted.
2Strength
If the propeller shaft uses a fixed coupling between interior and exterior hubs, then structural integrity is maintained, but the collapse load increases during collision
Solution Approach 1:
The coupling between interior and exterior hubs transitions from a static fixed connection to a dynamic system that can lock and unlock. The locking protrusion engages with the locking groove to maintain structural integrity during normal operation, but can be released during collision to reduce collapse load, providing adaptive structural response.
Solution Approach 2:
The mechanical state of the hub coupling changes from locked to unlocked based on collision conditions. The locking device alters the connection parameters between hubs dynamically, maintaining rigidity when needed and allowing movement when collision occurs, thus resolving the contradiction between structural integrity and collision force reduction.
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 locking device effectively reduces the collapse load during collisions, improving impact performance and enhancing passenger safety by allowing the hubs to separate and increase their overlap, thus absorbing the collision load without generating additional resistance.
Implementation Method 1
a switch coupled inside the case to axially movable while being elastically supported by a spring
Implementation Method 2
ring springs may support the stoppers while surrounding circumferences thereof
Data Source
AI summary
A propeller shaft with a locking device includes a locking device for selectively coupling an exterior hub and an interior hub thereof. The propeller shaft has a structure that enables sliding between the interior and exterior hubs including a spline portion while the locking device is released by the load during a collision.