Leaf-Spring Bushing Retainer Ring Lubricant Cavity

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Solution Overview

Problem

Conventional elastomeric bushings in vehicle leaf-spring suspension systems experience noise due to contact between elastomeric material and metal components, and applied grease is washed away quickly, especially in exposed conditions.

Innovation Solution

A bushing design featuring a cylindrical sleeve with an elastomeric member and a rigid retainer ring, where the elastomeric member has circumferential channels and a lubricant is trapped between the retainer ring and the elastomeric member, minimizing contact with metal and preventing grease washaway.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-generated harmful factors

If grease is applied to the surface of the terminal portions to reduce noise, then noise reduction is improved, but the grease is washed away quickly

Engineering Contradiction:
ImprovenoiseVSAvoidgrease retention
Core Design Contradiction:
Object-generated harmful factorsVSDuration of action of stationary object

Solution Approach 1:

A lubricant is introduced as an intermediary substance between the retainer ring and elastomeric member, contained within the sealed cavity formed by the retainer ring and bushing housing. This intermediary lubricant reduces friction and noise while being protected from washaway by the enclosing structure.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The lubricant is extracted from the external environment and placed inside a sealed cavity formed by the retainer ring and bushing housing. This extraction protects the lubricant from being washed away while maintaining its noise-reducing function between the retainer ring and elastomeric member.

Inventive Principle:
Principle #2Taking out (Extraction)

2Stability of the object's composition

If elastomeric material contacts metal components to secure the bushing, then structural stability is improved, but noise is generated

Engineering Contradiction:
Improvestructural stabilityVSAvoidnoise
Core Design Contradiction:
Stability of the object's compositionVSObject-generated harmful factors

Solution Approach 1:

A lubricant is introduced as an intermediary substance between the retainer ring (metal) and elastomeric member, reducing direct friction and noise-generating contact while maintaining the structural connection between metal and elastomeric components.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The friction parameters between contacting surfaces are changed by introducing lubricant, transforming the high-friction noisy contact between elastomeric material and metal into a low-friction quiet interface, while maintaining structural stability.

Inventive Principle:
Principle #35Parameter changes

3Ease of operation

If a rigid retainer ring is positioned over the elastomeric member to limit travel, then positional control is improved, but contact noise increases

Engineering Contradiction:
Improvepositional controlVSAvoidcontact noise
Core Design Contradiction:
Ease of operationVSObject-generated harmful factors

Solution Approach 1:

The lubricant acts as a mediator between the rigid retainer ring and elastomeric member, allowing the retainer ring to maintain its positional control function while the lubricant reduces the noise of contact between these components.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 design reduces noise and maintains lubrication, allowing for side-to-side movement of the leaf spring while preventing grease loss, thus enhancing durability and noise reduction.

Implementation Method 1

lubricant disposed between the retainer ring and the elastomeric member

Methodology Applied
Scientific EffectLubrication: Lubrication

Implementation Method 2

Bushings dampen vibration transfer between the leaf springs and the vehicle

Methodology Applied
Scientific EffectVibration damping: Damping

Data Source

PatentEP3181941B1Leaf-spring bushing
Publication Date: 2020.06.24 ANAND NVH PROD INC
  • EP3181941B1 patent drawingFigure 1
  • EP3181941B1 patent drawingFigure 2
  • EP3181941B1 patent drawingFigure 3

AI summary

A bushing for use in a vehicle leaf-spring suspension system, the bushing including a cylindrical sleeve including an internal passageway extending from first to second ends of the sleeve, the sleeve dimensioned to receive a shackle bolt therethrough; an elastomeric member at least substantially surrounding and extending radially outwardly from an exterior circumferential surface of the sleeve, and the elastomeric member having a pair of spaced-apart, circumferential channels positioned between the first and second ends of the sleeve, the channels dividing the elastomeric member into three radially-extending portions, one of which radially-extending portions is intermediate the other radially-extending portions; a rigid retainer ring positioned over the intermediate one of the radially-extending portions, the retainer ring having spaced-apart sidewalls extending into the circumferential channels so as to capture the intermediate one of the radially-extending portions therebetween; lubricant disposed between the retainer ring and the elastomeric member; and a housing surrounding an exterior circumferential surface of the elastomeric member and the retainer ring.