Double Path Torsional Damper Vibration Cancellation

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Solution Overview

Problem

Existing vehicle drive train systems face challenges in reducing engine vibration transmission through torque converters, particularly when the clutch is engaged, leading to excess wear on drivetrain components and passenger discomfort, due to undesirable resonant frequencies introduced by complex spring arrangements and the inertia of floating flanges.

Innovation Solution

A double path torsional vibration damper is introduced, featuring two parallel vibration paths with adjustable spring rates and flange inertias, allowing one path to be 180 degrees out of phase with the other, effectively canceling vibrations and reducing transmission of engine vibrations to the transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If complex spring arrangements are used to isolate engine vibration, then vibration isolation performance is improved, but undesirable resonant frequencies are introduced that cause increased vibrations

Engineering Contradiction:

Improvevibration isolation performanceVSAvoidundesirable resonant frequencies

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent divides the single vibration isolation path into two separate parallel paths, each with its own spring arrangement. This segmentation allows each path to be tuned to different frequency ranges, preventing the creation of a single dominant resonant frequency while maintaining effective vibration isolation across a broader frequency spectrum.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent changes the parameters of the spring arrangements in the two parallel paths, specifically tuning the spring rates and masses to create different natural frequencies for each path. By adjusting these parameters, the system avoids creating undesirable resonant frequencies while maintaining effective vibration isolation.

Inventive Principle:

Principle #35Parameter changes

2Object-generated harmful factors

If friction packages are introduced to absorb flange mode energy, then the additional degree of freedom is overcome, but isolation performance degrades at all frequencies other than the flange mode

Engineering Contradiction:

Improveflange mode vibrationVSAvoidisolation performance

Core Design Contradiction:

Object-generated harmful factorsVSReliability

Solution Approach 1:

Instead of using friction to absorb energy (which degrades isolation), the patent converts the potential harm of the flange mode by eliminating it entirely through the rigid flange design. The rigid structure prevents the flange from acting as a separate degree of freedom, thereby converting what would have been a harmful resonant mode into a stable, non-resonant structure that maintains isolation performance across all frequencies.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

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

The double path torsional vibration damper significantly reduces engine vibration transmission, minimizing drivetrain wear and passenger discomfort by customizing natural frequencies and spring rates to eliminate resonant frequencies within critical driving modes.

Implementation Method 1

the first pair of springs forms a first vibration path including the outer hub, the first pair of springs, the first flange and the output connection and the second pair of springs forms a second vibration path including the outer hub, the second pair of springs, the second flange and the output connection

Methodology Applied

Scientific EffectElasticity: Elasticity

Implementation Method 2

allowing one path to be 180 degrees out of phase with the other, effectively canceling vibrations and reducing transmission of engine vibrations to the transmission

Methodology Applied

Scientific EffectVibration: Vibration

Data Source

PatentUS8276720B2Double path torsional damper

Publication Date: 2012.10.02 SCHAEFFLER TECHNOLOGIES AG & CO KG

AI summary

The present invention is a double path torsion isolator for use in conjunction with a torque converter. Each of the two vibration paths includes a flange with a spring connection to each of the torque converter cover and an output connection attached to the transmission shaft. The torque converter turbine is connected to one of the flanges to provide a different frequency to the associated vibration path. When the lockup clutch is engaged, the engine vibration is divided along the two vibration paths toward the common output connection. The vibration frequency of the paths are adjusted so that the frequencies of the two paths are 180° out of phase at the output connection providing a vibration cancellation effect to the output connection.