Clutch Backing Plate Radial Drain for Spin Loss Reduction

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Solution Overview

Problem

Friction pack clutches in automatic transmissions experience increased spin losses due to hydraulic fluid flow from adjacent components into disengaged clutch packs, leading to reduced transmission efficiency and increased fuel consumption.

Innovation Solution

A backing plate with a radial shoulder and circumferential groove that directs hydraulic fluid radially outward through radial passageways, preventing fluid flow into adjacent disengaged clutch packs and reducing spin losses.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If hydraulic fluid is delivered to lubricate and cool friction clutch packs, then lubrication and cooling are improved, but spin losses in disengaged clutch packs increase due to fluid flow through relaxed plates or discs

Engineering Contradiction:

Improvecooling of friction clutch packsVSAvoidspin losses in disengaged clutch packs

Core Design Contradiction:

TemperatureVSLoss of energy

Solution Approach 1:

The backing plate is segmented with multiple radial drain holes distributed across its surface, creating separate fluid egress paths that redirect hydraulic fluid away from adjacent clutch packs while maintaining effective cooling of the engaged clutch pack

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The circumferential groove acts as an intermediary structure that collects hydraulic fluid from the engaged clutch pack and channels it through radial drain holes, preventing direct fluid flow into adjacent disengaged clutch packs while maintaining the lubrication and cooling function

Inventive Principle:

Principle #24Intermediary (Mediator)

2Temperature

If hydraulic fluid flows through disengaged clutch packs for cooling, then cooling is improved, but transmission efficiency decreases due to increased spin losses

Engineering Contradiction:

Improvecooling of friction clutch packsVSAvoidtransmission efficiency

Core Design Contradiction:

TemperatureVSProductivity

Solution Approach 1:

The backing plate structure creates different fluid flow characteristics in different regions: engaged clutch packs receive lubrication and cooling, while disengaged clutch packs are protected from fluid intrusion through the circumferential groove and radial drain hole configuration, optimizing both cooling and efficiency locally

Inventive Principle:

Principle #3Local quality

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 spin losses in disengaged friction clutch packs by diverting hydraulic fluid away from adjacent clutch packs, enhancing transmission efficiency and reducing fuel consumption.

Implementation Method 1

The circumferential groove collects hydraulic fluid and the radial passageways, aided by centrifugal force, direct hydraulic fluid flow radially outwardly

Methodology Applied

Scientific EffectCentrifugal force: Centrifugal Force

Data Source

PatentUS8932169B2Clutch backing plate with fluid drain

Publication Date: 2015.01.13 GM GLOBAL TECHNOLOGY OPERATIONS LLC

AI summary

A backing plate for a friction clutch pack includes a shoulder or flange through which a plurality of radial drain passageways extend. The radial drain passageways intersect a circumferential channel which collects hydraulic fluid from the friction clutch. The radial passageways, assisted by centrifugal force, direct hydraulic fluid flow radially outwardly, away from other friction pack clutches and thus prevent such fluid from creating drag and causing increased spin losses as it flows to and through disengaged clutch packs.