Clutch Hub Damper Assembly Reduces Squawk Noise
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Solution Overview
Problem
The 6R140 transmission experiences significant squawk noise during the 3-4 upshift due to self-excitation of the oncoming clutch, despite the use of ATF additives and friction compounds, and aftermarket clutch upgrades do not effectively address this issue without increasing mass or reducing power.
Innovation Solution
A squawk reducing clutch hub assembly with a damper system inside the E clutch hub, featuring a lower and upper damper thrust washer, a damper hub with lubrication openings, and a damper pressure plate with teeth, which creates drag to absorb the noise without adding substantial mass or power loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If friction compounds with higher coefficient are used to increase clutch holding capacity, then clutch holding capacity is improved, but squawk noise increases
Solution Approach 1:
A damper assembly is introduced as an intermediary component between the clutch plates to absorb vibrations and reduce squawk noise. The damper includes a damper spring that acts as a mediator to cushion the interaction between clutch components, allowing high-friction materials to be used without the full noise penalty.
Solution Approach 2:
The invention changes physical parameters by introducing a damper spring with specific stiffness characteristics and oil damping properties. These parameter changes allow the system to maintain high clutch holding capacity while reducing the amplitude and frequency of squawk noise through controlled mechanical damping.
2Strength
If clutch surface area is increased to improve holding capacity, then clutch holding capacity is improved, but transmission assembly mass increases
Solution Approach 1:
Instead of uniformly increasing the entire clutch pack size, the invention applies local quality enhancement by adding the damper assembly specifically at the clutch hub location. This localized intervention provides the necessary damping function without requiring a proportional increase in the entire clutch surface area or transmission mass.
3Object-generated harmful factors
If damper assembly is added to reduce squawk, then squawk noise is reduced, but device complexity increases
Solution Approach 1:
The damper assembly is nested within the existing clutch hub structure. The damper spring and associated components are contained within the clutch hub bore, utilizing the existing spatial envelope. This nesting approach allows the damping function to be added without substantially increasing the overall clutch hub assembly complexity or requiring major structural redesigns.
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
Effectively reduces clutch squawk noise during the 3-4 upshift by utilizing friction drag and lubrication to suppress self-excitation, compatible with both OEM and aftermarket clutches without increasing costs or power loss.
Implementation Method 1
The damper waved spring is seated within the open annular groove of the damper pressure plate and is biased against the annular lip, thereby placing pressure onto the damper pressure plate, which helps create drag on both the upper damper thrust washer and the lower damper thrust washer during the 3-4 up shift
Implementation Method 2
I have added several holes or lube openings, cross drilled (radially along the damper hub) on the damper hub to guide the lube oil up and to the outer diameter of the clutch hub, which also is grooved to help retain the oil while it exits through another set of holes on the clutch hub, the oil cooling and lubing the clutch plates
Data Source
AI summary
An E clutch hub assembly for the Ford 6R140 transmission, that reduces the squawk noise that occurs during the 3-4 upshift. A clutch hub has a lower pressure washer onto which is stacked a damper hub having radially located lube holes to direct lube to the E clutch plates. An upper pressure washer is stacked onto the damper hub while a pressure plate, seated within a snap ring rove machined into the hub, applies pressure onto the two pressure washers which help absorb the squawk noise. A waved spring holds the entire assembly within the hub.