Synchronizing Ring Assembly Friction Lining

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Solution Overview

Problem

Synchronizer ring sets experience a decrease in coefficient of friction over their service life due to mutual smoothing of friction surfaces, requiring increased axial pressure for synchronization and complex production processes for friction linings with different pairings.

Innovation Solution

A synchronizer ring set with a brass synchronizing ring having a smooth friction surface with embedded harder particles in a crystalline base material and a steel synchronizing ring with an organic friction lining containing filler particles of higher hardness, ensuring constant friction surface characteristics and preventing wear-induced changes in friction coefficient.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If friction surfaces are ground and honed to achieve initial synchronization, then the coefficient of friction is sufficient for synchronization, but the coefficient of friction decreases over service life due to mutual smoothing

Engineering Contradiction:
Improvesynchronization performanceVSAvoidservice life
Core Design Contradiction:
ReliabilityVSDuration of action of moving object

Solution Approach 1:

The friction surface uses a composite structure with a brass base material and embedded harder particles (such as PTFE, graphite, or ceramic particles). This composite structure maintains the self-lubricating properties of brass while the embedded harder particles prevent mutual smoothing during operation, keeping the coefficient of friction constant throughout the service life.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The invention changes the physical-chemical parameters of the friction surface by embedding particles with different hardness characteristics. This creates a surface where the harder particles resist wear and prevent the softening effect that would otherwise occur during frictional contact, thereby maintaining consistent friction characteristics over time.

Inventive Principle:
Principle #35Parameter changes

2Force

If a brass synchronizing ring has a thread as friction surface, then friction can be generated, but the contact surface changes due to reduction in thread height with wear

Engineering Contradiction:
Improvefriction forceVSAvoidthread height
Core Design Contradiction:
ForceVSShape

Solution Approach 1:

Instead of relying on the thread form alone, the invention creates a composite friction surface on the thread where harder particles are embedded in the brass material. This allows the thread structure to generate friction while the embedded particles maintain the surface geometry even as the thread height reduces during wear.

Inventive Principle:
Principle #40Composite materials

3Reliability

If friction linings are glued onto brass synchronizing ring, then friction surface is provided, but production effort becomes complex

Engineering Contradiction:
Improvefriction surface qualityVSAvoidproduction process
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention applies local quality modification by embedding harder particles directly into the brass friction surface at the specific locations where friction occurs. This localized treatment provides the necessary friction characteristics without requiring complex multi-step lining processes.

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

Maintains a constant coefficient of friction and synchronization behavior over the service life by embedding harder particles in softer base materials, preventing surface smoothing and ensuring consistent friction performance.

Implementation Method 1

Synchronization is brought about by pressing on the two friction surfaces forming a friction pair, specifically by creating a frictional connection

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

Over the service life of such a synchronizing ring set, the coefficient of friction of such a friction pairing can decrease due to the mutual smoothing of the friction surfaces

Methodology Applied
Scientific EffectWear: Wear

Data Source

PatentEP2459895B1Synchronizing ring assembly
Publication Date: 2012.11.14 OTTO FUCHS
  • EP2459895B1 patent drawingFigure 1~3
  • EP2459895B1 patent drawingFigure 2~4

AI summary

A synchronizing ring assembly (1) comprises at least two synchronizing rings (2, 3, 4). The latter each have a frictional surface (7, 8; 15, 16) which can be placed into operative connection to one another to form a friction pairing. At least one of the two synchronizing rings is manufactured from a steel material and the other from a brass material. The brass-material synchronizing ring has a structure in which harder particles P are incorporated into a softer crystalline base material. The frictional surface (8, 15) of the friction pairing of the steel-material synchronizing ring (3), which frictional surface is complementary to the other frictional surface, is formed by a friction lining (13, 14) consisting of an organic binder with filler particles incorporated therein, wherein the filler particles are harder than the binder. A method for forming the friction linings of a synchronizing ring (3) having two friction linings (13, 14) arranged concentrically with respect to each other is defined in that use is made of an injection-mouldable and/or transfer-mouldable plastics compound and the latter is applied by means of a plastics injection-moulding or transfer-moulding method from one side of the ring section (9) which is to be coated, and the friction lining compound is guided through apertures (11, 12) in the ring section (9) from the casting side onto the ring section surfaces which are provided for forming the frictional surfaces (13, 14).