Propeller Shaft Impact Absorption Using Collet and O-Ring

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Solution Overview

Problem

Existing impact energy absorbing propeller shafts face challenges such as increased processing time and strength deterioration due to stress concentration from plastic swaging, and they do not adequately absorb impact energy or reduce the number of components effectively.

Innovation Solution

A propeller shaft design incorporating a collet and O-ring between the front and rear shafts, where the collet is integrally and rotatably inserted with spline portions, and the O-ring is used to absorb impact energy by breaking under axial load, allowing the front shaft to move rearward and expand the collet, thereby absorbing energy and reducing the severity of injuries.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a swaging tube structure is used to absorb impact energy, then impact energy absorption function is improved, but manufacturing time and cost increase due to plastic swaging processing

Engineering Contradiction:

Improveimpact energy absorption functionVSAvoidmanufacturing time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent extracts the impact energy absorption function from the complex swaging tube structure and implements it through a simpler telescopic tube mechanism. The telescopic tube can slide axially within the main tube, providing impact absorption without requiring plastic deformation processing, thereby reducing manufacturing time while maintaining the absorption function.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the operational parameter from plastic deformation (swaging) to elastic deformation and friction. The telescopic tube uses friction between its outer surface and the inner surface of the main tube, along with friction between expansion ribs and the main tube, to absorb impact energy through controlled sliding and expansion rather than permanent plastic deformation.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If plastic swaging processing is applied to form swaging tube structure, then impact energy absorption is achieved, but strength deteriorates due to stress concentration

Engineering Contradiction:

Improveimpact energy absorptionVSAvoidpropeller shaft strength

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

The patent removes the stress concentration issue by eliminating the swaging tube structure that causes localized plastic deformation. Instead, it uses a telescopic tube that absorbs energy through controlled sliding and friction, avoiding the creation of stress concentration points while maintaining impact absorption capability.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The telescopic tube structure provides beforehand cushioning through its ability to slide and expand before impact occurs. The friction-based resistance mechanism is pre-configured to gradually absorb impact energy, preventing sudden stress concentration that would occur with swaging structures during collision.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

3Device complexity

If shear pin structure is used to absorb impact energy, then component simplicity is improved, but impact energy absorption effectiveness is insufficient

Engineering Contradiction:

Improvenumber of componentsVSAvoidimpact energy absorption effectiveness

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The telescopic tube serves multiple functions: it acts as both a structural component for power transmission and an impact energy absorption device. The same telescopic tube structure provides both mechanical coupling between shafts and friction-based energy absorption, eliminating the need for separate shear pins or additional absorption components.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent introduces dynamic behavior through the telescopic tube's ability to slide axially and expand during impact. This dynamic response allows the structure to adapt to impact forces in real-time, providing effective energy absorption through controlled motion and friction, whereas static structures like shear pins offer limited absorption capability.

Inventive Principle:

Principle #15Dynamics

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

This design effectively absorbs impact energy with a small collapse load, reduces the severity of injuries, and minimizes the number of components and material costs, while optimizing strength and natural frequency by eliminating the swaging structure.

Implementation Method 1

the O-ring is used to absorb impact energy by breaking under axial load

Methodology Applied

Scientific EffectImpact Force: Impact Force

Implementation Method 2

allowing the front shaft to move rearward and expand the collet, thereby absorbing energy

Methodology Applied

Scientific EffectDeformation: Deformation

Data Source

PatentUS9863481B2Impact energy absorbing propeller shaft

Publication Date: 2018.01.09 HYUNDAI MOTOR CO LTD

AI summary

An impact energy absorbing propeller shaft may include a collet integrally and rotatably inserted between a spline portion formed on an outer circumferential surface of a front shaft and a spline portion formed on an inner circumferential surface of a rear shaft, and an O-ring fitted with an outer circumferential surface of a rear end portion of the collet, fixedly holding a rear end portion of the front shaft, and fixedly supporting the collet inside the rear shaft.