Variable-Section Coil Spring for Drivetrain Torsional Vibration Decoupling

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Solution Overview

Problem

Existing drivetrain systems in motor vehicles face challenges in efficiently transmitting torque while effectively decoupling and damping torsional vibrations, particularly under varying environmental conditions and loads, with existing solutions either losing damping effectiveness or requiring complex designs that are not space-efficient.

Innovation Solution

A spiral coil spring with varying cross-section, specifically increasing in height and/or width along its length, is used for torque transmission and vibration decoupling, allowing for load-dependent spring stiffness and supercritical decoupling with minimal damping, utilizing a metallic design resistant to temperature and media exposure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a conventional coil spring is used for torque transmission, then torque can be transmitted between drive wheels, but the spring axis must be aligned with the torque transmission axis, limiting design flexibility

Engineering Contradiction:
Improvedesign flexibilityVSAvoidalignment requirements
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The coil spring is divided into multiple individual coils rather than a continuous helical structure. This segmentation allows each coil to be positioned independently, enabling the spring axis to be offset from the torque transmission axis while still effectively transmitting torque through the distributed coil structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention introduces an offset between the spring axis and the torque transmission axis, utilizing a different spatial arrangement. The multiple coils are distributed in a pattern that allows torque transmission along one axis while the physical structure exists along a different axis, effectively using dimensional separation to resolve the alignment constraint.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Reliability

If the coil spring has high stiffness for torque transmission, then torque is transmitted effectively, but vibration decoupling and damping capabilities are reduced

Engineering Contradiction:
Improvetorque transmission effectivenessVSAvoidvibration and shocks
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

Different regions of the coil spring structure have different properties. The overall structure maintains sufficient stiffness for torque transmission, while local coil configurations and mounting arrangements provide vibration decoupling. The individual coils can deform independently to absorb vibrations while the collective structure transmits torque effectively.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The coil spring utilizes a composite structure combining rigid elements (for torque transmission) and flexible elements (for vibration damping). The spring structure itself acts as a composite system where the coil geometry and material properties are optimized to provide both stiffness and damping characteristics simultaneously.

Inventive Principle:
Principle #40Composite materials

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 spiral coil spring ensures reliable torque transmission and efficient vibration decoupling with minimal damping, maintaining performance across varying conditions and reducing maintenance needs due to its metallic construction and adaptable design.

Implementation Method 1

a coil spring (1) for torque transmission in a drivetrain of a motor vehicle

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

for vibration decoupling and/or damping torsional vibrations

Methodology Applied
Scientific EffectVibration damping: Damping

Data Source

PatentEP2998608B1Coil spring for torque transmission in a drivetrain of a motor vehicle and for vibration decoupling and/or damping torsional vibrations
Publication Date: 2022.11.09 MAN TRUCK & BUS SE
  • EP2998608B1 patent drawingFigure 1~2
  • EP2998608B1 patent drawingFigure 3
  • EP2998608B1 patent drawingFigure 4

AI summary

The invention relates to a spiral spring (1) for torque transmission in a drive train of a motor vehicle and for vibration decoupling and/or damping of torsional vibrations. The spiral spring (1) has a cross-section that increases at least in sections as a function of length. The invention also includes a drive train module (10) with at least one spiral spring (1) according to the invention.