Composite Steering Bushing Axial Radial Play Design

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Solution Overview

Problem

Existing elastic bushings for torsion beam axles in automobiles lack play in both axial and radial directions, necessitating expensive holders to provide axial movement, which increases production costs.

Innovation Solution

The elastic bushing design features an inner core with axial recesses for form-fitting delimiting elements, allowing play in both axial and radial directions without separate costly parts, with the delimiting elements fixed during assembly and a compact design that includes an elastomer layer for progressive damping.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If traditional elastic bushings are used with bent end regions and support rings, then radial play is achieved, but axial play is lost and expensive holders are required

Engineering Contradiction:
Improveproduction costVSAvoidholder requirement
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent combines the functions of radial limiting and axial positioning into a single integrated limiting element. The limiting element features radially extending limitation portions that contact the inner core to provide radial play limitation, while axially extending limitation portions contact the support ring to provide axial play. This merging eliminates the need for separate expensive holders while achieving both radial and axial play characteristics.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The limiting element is designed as a multi-functional component that simultaneously performs multiple tasks: it limits radial movement through its radially extending portions, limits axial movement through its axially extending portions, and provides structural support. This universal component replaces what would traditionally require multiple separate parts including expensive holders, thereby reducing overall device complexity and cost.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Ease of operation

If delimiting elements are spaced axially from end regions, then axial play is achieved, but structural complexity increases

Engineering Contradiction:
Improveaxial playVSAvoidstructural complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The limiting element extends in multiple dimensions simultaneously - radially outward to contact the inner core and axially outward to contact the support ring. By utilizing both radial and axial dimensions from a single mounting location on the inner core, the design achieves axial play capability without adding structural complexity in the axial direction. The multi-dimensional design of the limiting element allows it to perform multiple functions from a compact structure.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 provides cost-effective play in both directions, ensuring easy handling and adjustable driving behavior without the need for expensive holders, while maintaining a compact and lightweight structure.

Implementation Method 1

An elastomer layer is inserted between the inner core and the outer sleeve

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

the elastic bushing according to the invention has play in the axial and radial directions

Methodology Applied
Scientific EffectDamping: Damping

Data Source

PatentEP2478254B1Elastic bushing, in particular composite steering bushing
Publication Date: 2014.03.12 TRELLEBORG AUTOMOTIVE GERMANY GMBH
  • EP2478254B1 patent drawingFigure 1~2
  • EP2478254B1 patent drawingFigure 3~4
  • EP2478254B1 patent drawingFigure 5

AI summary

The invention relates to an elastic bushing (10), in particular a composite steering bushing having an inner core (11) and an outer sleeve (12) disposed concentrically to one another, and connected to each other by an elastomer layer (13). A limiting element (18, 19) is disposed between the inner core (11) and the outer sleeve (12), limiting the radial displacement of the inner core (11). The outer sleeve (12) comprises an inwardly bent end region (26). In order to provide a cost-effective elastic bushing providing clearance in the radial and axial directions, according to the invention, the inner core (11) comprises at least one molded recess (16) in the axial direction, the at least one limiting element (18, 19) is positively inserted in the recess (16), the limiting element (18, 19) is at a distance from the end region (26) in the axial direction, and the end region (26) limits the axial displacement of the inner core (11). The invention further relates to a method for producing the elastic bushing (10) according to the invention.