Clutch Vibration-Damping Assembly With Switchable Deflection Mass

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Solution Overview

Problem

Existing vibration damping arrangements in vehicle drive trains do not effectively address the issue of torsional vibrations, particularly at higher frequencies and speeds, leading to secondary resonance issues.

Innovation Solution

A clutch system with a vibration damping arrangement featuring a deflection mass carrier and a deflection mass arrangement coupled by a restoring force generation mechanism, where the deflection mass arrangement is held fixed at low acceleration and allowed to move relative to the deflection mass carrier at higher acceleration, effectively switching to a rigid coupling state at higher speeds to avoid secondary resonance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a vibration damping arrangement with a deflection mass carrier and deflection mass assembly is used, then vibration damping is improved, but secondary resonance peaks occur at higher frequencies

Engineering Contradiction:
Improvevibration dampingVSAvoidsecondary resonance peaks
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The coupling between the deflection mass assembly and the deflection mass carrier is made dynamically switchable. At low accelerations, the coupling elements (friction device and/or restoring force generation arrangement) maintain a flexible coupling that allows relative motion for vibration damping. At high accelerations exceeding a threshold value, the coupling switches to a rigid state that prevents relative motion, thereby eliminating the secondary resonance peaks that would otherwise occur at higher frequencies.

Inventive Principle:
Principle #15Dynamics

2Reliability

If the deflection mass assembly is allowed to move freely relative to the deflection mass carrier, then vibration damping is enhanced, but the system becomes less stable at high speeds

Engineering Contradiction:
Improvevibration dampingVSAvoidsystem stability at high speeds
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The system changes its mechanical parameters (coupling stiffness) based on the acceleration level. The coupling elements are designed to transition from a compliant state at low accelerations to a rigid state at high accelerations. This parameter change is achieved through the friction device and/or restoring force generation arrangement, which provide flexible coupling under normal conditions but lock into a rigid configuration when threshold acceleration is exceeded, thus maintaining stability at high speeds.

Inventive Principle:
Principle #35Parameter changes

3Stability of the object's composition

If a rigid coupling is used between the deflection mass assembly and deflection mass carrier, then system stability is improved, but vibration damping capability is reduced

Engineering Contradiction:
Improvesystem stabilityVSAvoidvibration damping capability
Core Design Contradiction:
Stability of the object's compositionVSReliability

Solution Approach 1:

Rather than using a permanently rigid coupling, the invention employs a dynamic coupling mechanism that adapts its stiffness based on operating conditions. The friction device and/or restoring force generation arrangement enable the system to switch between flexible and rigid coupling states. This dynamic approach allows the system to maintain flexible coupling for optimal vibration damping during normal operation, while automatically transitioning to rigid coupling for enhanced stability when high accelerations are detected.

Inventive Principle:
Principle #15Dynamics

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 solution enhances vibration damping behavior by increasing the moment of inertia at low acceleration and acting as an absorber at higher acceleration, thereby reducing torsional vibrations and avoiding secondary resonance peaks at higher frequencies.

Implementation Method 1

a holding force generated by a friction device relative to the deflection mass carrier. It should be noted that the friction device is supported or rubs against the deflection mass carrier on one side and against the deflection mass assembly

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

The deflection mass assembly is coupled to the deflection mass carrier by a restoring force generation assembly, so that when torsional vibrations occur and the deflection mass carrier vibrates accordingly, the deflection mass assembly is deflected against the restoring force of the restoring force generation assembly

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 3

When rotational irregularities or torsional vibrations occur, the deflection mass carrier is set into a oscillatory motion superimposed on the rotational motion. The deflection mass assembly is deflected against the restoring force of the restoring force generation assembly with respect to the deflection mass carrier and set into a vibratory motion with respect to the deflection mass carrier that contributes to damping the vibrations

Methodology Applied
Scientific EffectVibration: Vibration

Data Source

PatentEP3440381B1Clutch system with a vibration-damping assembly, in particular for a drive train of a vehicle
Publication Date: 2021.12.22 ZF FRIEDRICHSHAFEN AG
  • EP3440381B1 patent drawingFigure 1
  • EP3440381B1 patent drawingFigure 2~3
  • EP3440381B1 patent drawingFigure 4

AI summary

The invention relates to a vibration-damping assembly (10) for a drive train of a vehicle, comprising a deflection mass carrier (20), which can be set into vibrational motion, and a deflection mass assembly (22) carried on the deflection mass carrier (20). The deflection mass assembly (22) is coupled to the deflection mass carrier (20) by means of a restoring-force-generating assembly (24) in such a way that the deflection mass assembly (22) is substantially fixedly held in a resting position in relation to the deflection mass carrier (20) in the case of acceleration of the deflection mass carrier (20) lying below a threshold acceleration and the deflection mass assembly (22) can be deflected out of the resting position in relation to the deflection mass carrier (20) against a restoring force generated by the restoring-force-generating assembly (24) and/or by a retaining force generated by a friction device, in the case of acceleration of the deflection mass carrier (20) lying above the threshold acceleration.