Elastic Joint Body U-Shaped Collar Crack Prevention

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Solution Overview

Problem

Existing elastic joint bodies for shaft arrangements suffer from cracks in the rubber-elastic casing due to cardanic and bending stresses, and the manufacturing process is complex and costly due to issues with collar elements and ring plates.

Innovation Solution

The use of U-shaped collar components with a cross-section of two U-longitudinal limbs and one U-transverse limb, where the rubber is only connected to the U-transverse leg, and additional features like inclined longitudinal legs to prevent dirt and moisture accumulation, reduce friction, and simplify the manufacturing process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If L-shaped collars are pressed on for axial support of loop packs, then axial support is provided, but cracks occur on the surface of the rubber-elastic casing due to cardanic stresses and bending stresses

Engineering Contradiction:
Improveaxial support capabilityVSAvoidservice life of joint body
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The collar is divided into two separate functional parts: a U-shaped collar component that provides axial support and a rubber-elastic sheathing that surrounds it. The rubber is connected only to the U-transverse limb, creating a segmented connection that prevents stress concentration at a single point and eliminates crack formation.

Inventive Principle:
Principle #1Segmentation

2Strength

If L-shaped collars are used for axial support, then axial guidance is provided, but the manufacturing process becomes complex and costly due to cleaning and fastening requirements

Engineering Contradiction:
Improveaxial guidance capabilityVSAvoidmanufacturing process complexity
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The U-shaped collar component and rubber-elastic sheathing are combined into a single integrated assembly where the rubber is directly connected to the U-transverse limb. This merging eliminates the need for separate cleaning and fastening processes required by L-shaped collars and ring plates, simplifying manufacturing.

Inventive Principle:
Principle #5Merging (Combining)

3Strength

If ring plates are riveted to bushings for axial support, then axial support is provided, but rubber flows onto the ring plates during vulcanization requiring time-consuming cleaning

Engineering Contradiction:
Improveaxial support capabilityVSAvoidcleaning process time
Core Design Contradiction:
StrengthVSLoss of time

Solution Approach 1:

The problematic feature of complete rubber-to-collar connection is extracted and eliminated. The rubber is taken out from connecting to the U-longitudinal limbs and only connected to the U-transverse limb, preventing rubber flow onto surfaces that would require cleaning while maintaining axial support functionality.

Inventive Principle:
Principle #2Taking out (Extraction)

4Ease of operation

If torque is transmitted to collars during assembly, then assembly is possible, but the collars are twisted relative to the connected rubber mass causing cracks

Engineering Contradiction:
Improveassembly capabilityVSAvoidservice life of joint body
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The connection between rubber and collar is made local and selective rather than comprehensive. The rubber is connected only to the U-transverse limb, creating a localized connection point that can accommodate torque during assembly without transmitting twisting forces to the entire collar structure, preventing crack formation.

Inventive Principle:
Principle #3Local quality

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 prevents cracks in the rubber-elastic casing, enhances the mechanical rigidity and service life of the joint body, simplifies the manufacturing process, and reduces costs by eliminating cleaning and fastening processes, while maintaining or improving torque transmission capabilities.

Implementation Method 1

a rubber-elastic casing (12) in which the loop packs (16) and the sockets (14) are at least partially embedded

Methodology Applied
Scientific EffectRubber elasticity: Elasticity

Data Source

PatentEP2283245B1Elastic joint body
Publication Date: 2011.12.28 SUDDEUTSCHE GELENKSCHEIBENFABRIK GMBH & CO KG
  • EP2283245B1 patent drawingFigure 1
  • EP2283245B1 patent drawingFigure 2a~2e
  • EP2283245B1 patent drawingFigure 3

AI summary

The present invention relates to an elastic joint body (10) for a shaft arrangement for the articulated connection of two shaft bodies, with a plurality of bushings (14) which are arranged in the circumferential direction at predetermined angular distances from a centre axis (M) of the joint body (10), a plurality of loop bundles (16), wherein each loop bundle (16) loops around in each case two adjacent bushings (14), and with a rubber-elastic casing (12) in which the loop bundles (16) and the bushings (14) are at least partially embedded. According to the invention, a collar (18, 20, 22, 24) is provided on at least one end region on at least one of the bushings (14) for the axial support of an adjacent loop bundle (16), said collar encircling the bushing (14), being at least partially embedded in the rubber-elastic casing (12) and having a U-shaped cross section, as viewed in the axis-containing section, wherein the cross section is designed with two U longitudinal limbs (30, 32) and one U transverse limb (34), wherein the collar (18, 20, 22, 24) bears with a U longitudinal limb (30, 32) against the bushing (14).