Synchronizer Ring Arcuate Grooves Drag Torque

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Solution Overview

Problem

Existing synchronization device rings in motor vehicle transmissions face challenges in achieving low drag torque and high wear resistance, leading to inefficiencies and increased friction, which are not effectively addressed by prior art methods.

Innovation Solution

The method involves creating arcuate grooves on the sliding surfaces of the ring using the vortex turning process, with intersecting grooves arranged on the end face, and optionally coating or making the grooves from sliding materials like bronze or plastic, to minimize friction and enhance lubrication.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the friction surface is designed for high wear resistance, then the number of shifts that can be synchronized increases, but the drag torque increases due to increased friction

Engineering Contradiction:
Improvewear resistanceVSAvoiddrag torque
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent applies the principle of porous materials by introducing arcuate grooves into the sliding surface of the synchronizer ring. These grooves create a porous-like structure that allows lubricant to be retained and distributed effectively in the contact area, reducing friction and drag torque while maintaining wear resistance of the friction surface

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The patent applies local quality by differentiating the properties of different surfaces: the friction surface is designed for high wear resistance to handle synchronization wear, while the sliding surface incorporates arcuate grooves for lubricant retention to minimize drag torque. This localized differentiation allows each surface to optimize its specific function without compromising the other

Inventive Principle:
Principle #3Local quality

2Loss of energy

If arcuate grooves are introduced on sliding surfaces, then drag torque is reduced through improved lubrication, but manufacturing complexity increases

Engineering Contradiction:
Improvedrag torqueVSAvoidproduction complexity
Core Design Contradiction:
Loss of energyVSEase of manufacture

Solution Approach 1:

The patent applies curvature by using arcuate grooves that follow the circular contour of the ring's end face. This curved geometry is naturally suited to rotational machining processes like vortex turning, where the tool rotates around the workpiece axis, making the curved grooves easier to manufacture with standard equipment compared to straight or complex patterns

Inventive Principle:
Principle #14Spheroidality (Curvature)

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 significantly reduces drag torque, allowing for efficient operation with minimal unwanted friction, thereby improving the overall efficiency of the transmission while being cost-effective in production.

Implementation Method 1

at least one of the sliding surfaces has a number of arcuate grooves which are introduced by a vortex turning process

Methodology Applied
Scientific EffectWhirling (vortex turning):

Implementation Method 2

The introduced arcuate grooves enable an optimal build-up of a lubricating film by a lubricant, so that a low-wear sliding of the partners involved is made possible

Methodology Applied
Scientific EffectLubrication: Lubrication

Data Source

PatentEP2406514B1Method for producing a ring of a synchronizing device, and a ring of a synchronizing device
Publication Date: 2013.01.09 AB SKF SKF PATENT DEPARTMENT
  • EP2406514B1 patent drawingFigure 1~3

AI summary

The invention relates to a method for producing a ring (1) of a synchronizing device (2), wherein the ring (1) has a frictional surface (3) for interacting with the frictional surface (4) of a further ring (5) of the synchronizing device (2), and at least one sliding surface (6, 7) to form a sliding seat on a contact surface (8). In order to achieve a low drag torque of the ring, the invention provides for at least one of the sliding surfaces (6, 7) to have a number of arcuate grooves (9, 10), which are introduced by a thread turning process. Furthermore, the invention relates to a ring of a synchronizing device.