Lockup Clutch Backing Plate Structure for Torsional Load Damping

Solution Overview

Problem

Conventional lockup clutch assemblies in torque converters for transmission systems face challenges in efficiently transitioning between fluid coupling and mechanical coupling modes, leading to torque transmission inefficiencies and increased wear due to inadequate load distribution and damping mechanisms.

Innovation Solution

The introduction of a novel backing plate design with a radial lip and a single-piece bent assembly that enhances load distribution and damping through a combination of radial fingers and a damper system, allowing for improved torsional load transfer and reduced axial deflection during clutch engagement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional lockup clutch assembly is used, then the torque converter can transmit torque, but torque transmission efficiency is reduced and wear increases due to inadequate load distribution and damping mechanisms

Engineering Contradiction:

ImprovedurabilityVSAvoidtorque transmission efficiency

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The clutch assembly is divided into multiple clutch plates (first clutch plate, second clutch plate) with distinct functions. The first clutch plate is splined to the input shaft for torque input, while the second clutch plate engages with the turbine for torque output. This segmentation allows for better load distribution across separate engagement surfaces, reducing wear on individual plates and improving overall torque transmission efficiency.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A damper system is integrated into the clutch assembly to provide damping during engagement transitions. The damper absorbs shock loads and torsional vibrations that occur during clutch engagement and disengagement, protecting the clutch plates and surrounding components from excessive wear and improving durability before damage can occur.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

2Reliability

If a conventional clutch assembly design is used, then the structure is simpler, but load distribution is inadequate leading to increased wear

Engineering Contradiction:

Improvewear resistanceVSAvoidclutch assembly structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The clutch assembly is divided into multiple clutch plates (first clutch plate, second clutch plate) with distinct functions. The first clutch plate is splined to the input shaft for torque input, while the second clutch plate engages with the turbine for torque output. This segmentation allows for better load distribution across separate engagement surfaces, reducing wear on individual plates and improving overall torque transmission efficiency.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The clutch plates are arranged in a nested configuration where the first clutch plate and second clutch plate are positioned axially adjacent to each other within the clutch assembly. The damper system is integrated between these plates, creating a compact nested structure that improves load distribution without significantly increasing the overall axial length or external dimensions of the clutch assembly.

Inventive Principle:

Principle #7Nested doll (Nesting)

3Loss of energy

If the clutch assembly lacks adequate damping mechanisms, then the structure is simpler, but torque transmission efficiency is reduced during mode transitions

Engineering Contradiction:

Improvetorque transmission efficiencyVSAvoiddamping mechanism

Core Design Contradiction:

Loss of energyVSDevice complexity

Solution Approach 1:

A damper system is integrated into the clutch assembly to provide damping during engagement transitions. The damper absorbs shock loads and torsional vibrations that occur during clutch engagement and disengagement, protecting the clutch plates and surrounding components from excessive wear and improving durability before damage can occur.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The damper system is merged with the clutch plate assembly rather than being a separate external component. The damper is positioned between the first and second clutch plates, combining the damping function with the torque transmission function in a single integrated structure, thereby improving torque transmission efficiency during transitions without proportionally increasing device complexity.

Inventive Principle:

Principle #5Merging (Combining)

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 design enhances torque transmission efficiency, reduces wear, and improves the overall performance of the torque converter by effectively managing torsional loads and axial forces during mode transitions, leading to improved durability and efficiency.

Implementation Method 1

a damper system, allowing for improved torsional load transfer and reduced axial deflection during clutch engagement

Methodology Applied

Scientific EffectDamping: Damping

Data Source

PatentUS11686377B2Torque converter lockup clutch structure

Publication Date: 2023.06.27 ALLISON TRANSMISSION INC

AI summary

A torque converter assembly that has a turbine assembly, a pump assembly, and a clutch assembly that selectively rotationally couples the turbine assembly to the pump assembly. The clutch assembly also has at least one clutch disk and a backing plate assembly defining a backing plate surface and formed by a first plate and a second plate coupled to one another. The first plate and the second plate are coupled to each other at a first radius and a second radius, the second radius being substantially adjacent to the backing plate surface.