Multi-piece Backing Plate for Automotive Transmission Clutch

Solution Overview

Problem

Existing friction clutch pack assemblies in automatic transmissions face challenges in achieving the required axial stiffness while meeting the need for lighter and cheaper components, as traditional backing plates are heavy and costly, and must prevent slippage effectively when engaged.

Innovation Solution

A multiple-piece backing plate design is introduced, featuring a cap part made of a material like steel to interact with the friction clutch plate and prevent slippage, combined with a main body backing plate made of a lighter material such as aluminum, which is attached through a castle joint or other means, allowing the clutch plates to be compressed directly against the cap part when engaged.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Weight of moving object

If a traditional single-piece steel backing plate is used, then axial stiffness and non-slipping engagement are ensured, but weight and cost increase

Engineering Contradiction:

Improvebacking plate weightVSAvoidaxial stiffness

Core Design Contradiction:

Weight of moving objectVSStrength

Solution Approach 1:

The backing plate is divided into two separate components: a cap part made of steel and a main body backing plate made of lighter material such as aluminum or magnesium alloy. These segments are attached together through various means including interference fit, mechanical fasteners, or bonding. This segmentation allows each part to be optimized for its specific function while reducing overall weight.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The steel cap part is strategically positioned at the location where axial stiffness and non-slipping engagement are most critical - where the friction clutch plates make contact. The lighter material is used for the main body where full strength is less critical. This local quality approach ensures performance is optimized at the interface while reducing weight in non-critical areas.

Inventive Principle:

Principle #3Local quality

2Reliability

If a traditional single-piece steel backing plate is used, then non-slipping engagement is ensured, but cost increases

Engineering Contradiction:

Improvenon-slipping engagementVSAvoidmanufacturing cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The backing plate is divided into two separate components: a cap part made of steel and a main body backing plate made of lighter material such as aluminum or magnesium alloy. These segments are attached together through various means including interference fit, mechanical fasteners, or bonding. This segmentation allows each part to be optimized for its specific function while reducing overall weight.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The steel cap part is strategically positioned at the location where axial stiffness and non-slipping engagement are most critical - where the friction clutch plates make contact. The lighter material is used for the main body where full strength is less critical. This local quality approach ensures performance is optimized at the interface while reducing weight in non-critical areas.

Inventive Principle:

Principle #3Local quality

3Weight of moving object

If the main body backing plate is made of lighter material, then weight is reduced, but axial stiffness may be compromised

Engineering Contradiction:

Improvebacking plate weightVSAvoidaxial stiffness

Core Design Contradiction:

Weight of moving objectVSStability of the object's composition

Solution Approach 1:

The backing plate is divided into two separate components: a cap part made of steel and a main body backing plate made of lighter material such as aluminum or magnesium alloy. These segments are attached together through various means including interference fit, mechanical fasteners, or bonding. This segmentation allows each part to be optimized for its specific function while reducing overall weight.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The steel cap part is strategically positioned at the location where axial stiffness and non-slipping engagement are most critical - where the friction clutch plates make contact. The lighter material is used for the main body where full strength is less critical. This local quality approach ensures performance is optimized at the interface while reducing weight in non-critical areas.

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS10215237B2Multiple-piece backing plate having parts made of different materials

Publication Date: 2019.02.26 GM GLOBAL TECHNOLOGY OPERATIONS LLC

AI summary

A multiple-piece backing plate and a friction clutch assembly for an automotive transmission are provided. The multiple-piece backing plate includes a cap part and a main body backing plate. The cap part is formed of a first material. The main body backing plate is attached to the cap part, and the main body backing plate is formed of a second material, where the second material is different than the first material. The friction clutch assembly includes first clutch plates coupled to a first transmission member and second clutch plates interleaved with the first clutch plates and coupled to a second transmission member. The friction clutch assembly is configured to be moved between an engaged position and a disengaged position. In the engaged position, the first and second transmission members are coupled together by compressing the first and second clutch plates directly against the cap part.