Friction Damper for Torque Transmission Noise Damping

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Solution Overview

Problem

Existing power take-off (PTO) gear systems experience undesirable noise due to angular fluctuations during engine idling and start-up, which current elastic elements and friction control plates fail to adequately dampen, especially due to space constraints and limited effectiveness in resonance conditions.

Innovation Solution

A torque transmitting device with a flange, curved slots, and a friction assembly featuring curved engagement and friction plates, along with a resilient element, which engages to dissipate torque and dampen rotation, providing both elastic and frictional damping without increasing axial space.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If elastic elements are used to dampen vibration, then idle condition vibration is reduced, but resonance condition attenuation is insufficient

Engineering Contradiction:

Improveidle condition noiseVSAvoidresonance condition damping

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent combines elastic elements and friction control plates into a unified damper system. The elastic elements (springs) provide damping for idle condition vibrations, while the friction control plates engage during resonance conditions to provide additional frictional damping, thereby resolving the contradiction between idle condition noise reduction and resonance condition attenuation.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The friction control plates are designed to dynamically engage and disengage based on operating conditions. During idle conditions, the elastic elements primarily absorb vibrations. During resonance conditions, the increased forces cause the friction control plates to engage, providing variable damping characteristics that adapt to the operating state, thus improving both idle and resonance condition performance.

Inventive Principle:

Principle #15Dynamics

2Reliability

If bumper springs are used for second stage damping, then vibration capacity increases, but axial and radial space requirements increase

Engineering Contradiction:

Improvevibration damping capacityVSAvoidaxial and radial space

Core Design Contradiction:

ReliabilityVSVolume of moving object

Solution Approach 1:

Instead of using bumper springs that require increased axial and radial space, the patent utilizes the circumferential dimension by positioning friction control plates around the perimeter of the damper assembly. This allows the second stage damping to be achieved in a different spatial dimension, maintaining compact axial and radial dimensions while providing enhanced vibration damping capacity.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Reliability

If friction control plates are used for large travel angle damping, then resonance damping improves, but effectiveness is limited by axial force and number of surfaces

Engineering Contradiction:

Improveresonance dampingVSAvoidaxial force requirements and friction surface count

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The friction control plates are designed with curved surfaces that conform to the circular path of the damper assembly. This curvature allows the plates to maintain continuous contact during large travel angles, maximizing the frictional damping effect without requiring excessive axial force or an increased number of friction surfaces, thereby improving resonance damping while controlling device complexity.

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

The solution effectively reduces noise by dissipating torque through frictional engagement, offering improved damping capacity while minimizing space requirements, addressing the limitations of existing solutions in resonance conditions and space constraints.

Implementation Method 1

a curved friction assembly including a first end disposed in the first curved slot, a second end disposed in the second curved slot, at least one curved engagement plate including an engagement tab extending radially inward, at least one curved friction plate rotationally fixed to the plate, and a resilient element urging the at least one curved engagement plate and the at least one curved friction plate into contact

Methodology Applied

Scientific EffectFriction: Friction

Implementation Method 2

at least one elastic element engaged with the flange

Methodology Applied

Scientific EffectElasticity: Elasticity

Data Source

PatentUS9133885B2Friction controlled damper for a torque transmission device

Publication Date: 2015.09.15 SCHAEFFLER TECHNOLOGIES AG & CO KG

AI summary

A flange forming an input for the device and including a damper stop tab extending radially outward; a plate including first and second curved slots; and a curved friction assembly including a first end disposed in the first curved slot, a second end disposed in the second curved slot, at least one curved engagement plate including an engagement tab extending radially inward, at least one curved friction plate rotationally fixed to the plate, and a resilient element urging the at least one curved engagement plate and the at least one curved friction plate into contact. The device includes at least one elastic element engaged with the flange.