Sintered Coupling Ring Density Gradient for Breakage Prevention

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Solution Overview

Problem

The existing manufacturing process for sintered clutch rings with radially projecting stops is prone to breakage and increases manufacturing costs due to the need for additional machining and risk of tool jamming during calibration.

Innovation Solution

The stops are produced with higher density through powder metallurgy, allowing them to withstand axial loads without breaking, and are calibrated to match the tooth crest width for reduced specific load and tool protection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If stops are produced by machining sintered clutch teeth with oversize, then the stops can be manufactured with powder metallurgy, but the risk of stops breaking increases and manufacturing costs increase

Engineering Contradiction:
Improvemanufacturing processVSAvoidrisk of breakage
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent applies local quality by creating a density gradient within the clutch tooth structure. The stops are produced with higher density (7.0-7.5 g/cm³) compared to the tooth head (6.8-7.2 g/cm³), making the stops locally stronger and more resistant to breaking while maintaining the overall powder metallurgy manufacturing process

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent applies preliminary action by forming the stops with oversize during the initial sintering process, then pre-compressing them before final calibration. This preliminary compression prepares the stops to withstand the subsequent calibration process without breaking, eliminating the need for machining and reducing the risk of breakage

Inventive Principle:
Principle #10Preliminary action

2Strength

If stops are compressed to high density during calibration, then the load capacity improves, but the compression tools may be overloaded

Engineering Contradiction:
Improveload capacity of stopsVSAvoidcompression tool capacity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The patent applies partial action by compressing only the stops to high density (7.0-7.5 g/cm³) while keeping the tooth head at a lower density (6.8-7.2 g/cm³). This selective compression achieves the required load capacity for the stops without requiring the entire clutch tooth to be compressed to maximum density, thereby reducing the load on compression tools

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The patent applies parameter changes by controlling the density of different regions of the clutch tooth through calibrated compression forces. The stops are compressed to a higher density parameter (7.0-7.5 g/cm³) than the tooth head (6.8-7.2 g/cm³), optimizing the load-bearing capacity of the stops while managing the compression tool requirements

Inventive Principle:
Principle #35Parameter changes

3Stress or pressure

If the stop surface area is increased to reduce specific load, then the load distribution improves, but the tooth geometry becomes more complex

Engineering Contradiction:
Improvespecific load on stop surfaceVSAvoidtooth geometry
Core Design Contradiction:
Stress or pressureVSShape

Solution Approach 1:

The patent applies segmentation by dividing the clutch tooth into distinct functional zones: the tooth head with lower density (6.8-7.2 g/cm³) and the stops with higher density (7.0-7.5 g/cm³). The stops are designed with a width corresponding to at least the thickness of the tooth crest, creating a segmented structure that optimizes load distribution on the stop surface while maintaining a relatively simple overall tooth geometry

Inventive Principle:
Principle #1Segmentation

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 approach enhances the load capacity of the stops, simplifies manufacturing, reduces the risk of breakage, and prevents tool jamming by distributing loads more evenly, thus ensuring reliable operation and extended tool life.

Implementation Method 1

a powder blank is pressed and sintered, the clutch teeth of which are formed with axis-parallel flanks

Methodology Applied
Scientific EffectSintering: Sintering

Implementation Method 2

to compress the stops sintered with oversize to the specified size during the calibrating process

Methodology Applied
Scientific EffectCompression: Compression

Implementation Method 3

the shaped projections of one matrix and the recesses for the shaped projections in the other matrix merge into the parting surface via wedge surfaces running in the radial direction

Methodology Applied
Scientific EffectWedge: Wedge

Data Source

PatentEP2485858B1Sintered coupling ring
Publication Date: 2013.07.24 MIBA SINTER AUSTRIA GMBH
  • EP2485858B1 patent drawingFigure 1~2
  • EP2485858B1 patent drawingFigure 3
  • EP2485858B1 patent drawingFigure 4~5

AI summary

The invention relates to a sintered coupling ring (1), comprising an annulus of coupling teeth (2), which have flanks (4) that are drawn back and that extend from wedge-shaped end faces (3) and, on the side opposite the wedge-shaped end faces (3), a stop (5) that protrudes radially beyond the tooth tip (6). In order to create advantageous design conditions, the stops (5) have a greater density than the remaining tooth tip (6).