Synchronizer Ring Assembly With Low-Adhesion Friction Interface

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Solution Overview

Problem

Existing synchronization units in gear change transmissions experience functional disturbances such as second pressure points or blocked shifts, particularly at low operating temperatures, due to sticking issues between the friction ring and synchronizer ring, which affects shifting comfort and efficiency.

Innovation Solution

The structural unit incorporates a friction ring with a conical friction surface and an installation surface, along with a synchronizer ring featuring an adhesion-reducing surface structure, such as indentations or coatings, to minimize adhesion and prevent sticking, allowing for independent optimization of synchronization torque and friction pairing release functions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If a friction ring with conical friction surface and mounting surface is used to generate synchronization torque, then high efficiency and significant amplification effect between actuation force and synchronization torque are achieved, but adhesion between the friction ring and synchronizer ring causes sticking issues especially at low operating temperatures

Engineering Contradiction:
Improvesynchronization torque amplificationVSAvoidshifting operation reliability
Core Design Contradiction:
PowerVSReliability

Solution Approach 1:

The mounting surface of the friction ring is given a specific geometric structure (protrusions, recesses, grooves, or holes) that creates localized regions with different adhesion properties. This local structural modification reduces adhesion in critical contact areas while preserving the friction characteristics needed for torque generation on the friction surface.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The geometric parameters of the mounting surface (protrusion height, recess depth, groove width, hole diameter) are optimized to control the contact area and pressure distribution between the friction ring and synchronizer ring. By changing these parameters, the adhesion force is reduced while maintaining sufficient friction for synchronization torque generation.

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If the friction surface and mounting surface are combined in one component, then spatial separation of functions is achieved, but the friction pair cannot be reliably disengaged due to adhesion

Engineering Contradiction:
Improvecomponent integrationVSAvoidfriction pair disengagement
Core Design Contradiction:
Device complexityVSEase of operation

Solution Approach 1:

The mounting surface incorporates geometric features (protrusions, recesses, grooves, or holes) that create localized low-adhesion zones. These structured regions allow the mounting function to be integrated with the friction ring while enabling reliable disengagement by reducing the adhesion force at the contact interface.

Inventive Principle:
Principle #3Local quality

3Loss of time

If a structured surface with oil grooves is used on the synchronizer ring, then lubricating oil is removed more quickly from friction surfaces, but adhesion between mounting surface and contact surface still causes sticking

Engineering Contradiction:
Improvesynchronization timeVSAvoidshifting comfort
Core Design Contradiction:
Loss of timeVSReliability

Solution Approach 1:

The mounting surface of the friction ring is structured with protrusions, recesses, grooves, or holes to reduce adhesion. This local structural modification addresses the sticking problem independently of the oil groove design on the synchronizer ring, ensuring reliable disengagement even when oil is quickly removed from the friction surfaces.

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 enhances shifting comfort and efficiency by reducing adhesion between the friction ring and synchronizer ring, preventing unintended sticking and maintaining spatial separation of functions, thereby improving operational reliability and comfort, especially at low temperatures.

Implementation Method 1

the inner friction surface of the friction ring is in frictional contact with the gear wheel. This frictional contact allows for speed synchronization between the gear and the friction ring

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

The mounting surface of the friction ring and/or the contact surface of the synchronizer ring have an adhesion-reducing surface structure

Methodology Applied
Scientific EffectAdhesion reduction: Friction

Data Source

PatentEP3112716B1Assembly for a synchronizing unit of a gear wheel change-speed gearbox
Publication Date: 2022.01.19 OERLIKON FRICTION SYST GERMANY
  • EP3112716B1 patent drawingFigure 1a~1b
  • EP3112716B1 patent drawingFigure 1c~1d
  • EP3112716B1 patent drawingFigure 2a~2b

AI summary

The invention relates to a component for a synchronization unit of a gear-shift transmission. The invention is based on a component comprising a synchronizer ring (7) and a friction ring (1). The friction ring (1) has a friction surface (301) and a mounting surface (302), and the synchronizer ring (7) has a contact surface (10) corresponding to the mounting surface (302). To enable high efficiency of the synchronization unit and simultaneously reliable and comfortable operation of the gear-shift transmission, the invention proposes that the friction ring (1) and the synchronizer ring (7) be made of different materials.