Friction Plate Segmentation for Wet Clutch Drag Torque Reduction

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Solution Overview

Problem

The manufacturing of friction plates for wet clutch and brake mechanisms faces challenges in achieving reliable and flexible production of friction facings with optimal performance, including contamination, lubricant fluid obstruction, and parasitic energy loss due to drag torque.

Innovation Solution

A method and apparatus for making friction plates by cutting friction material segments with cleanly scour-cut edges, remaining integrally connected to the sheet by ties, and bonding them to a core plate, using a rotary die cutting assembly and locator punch assembly to ensure precise placement and efficient lubricant flow.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If friction material segments are cut from a friction material sheet, then the friction facing can be formed on the core plate, but contamination and lubricant fluid obstruction occur due to poor separation quality

Engineering Contradiction:

Improveseparation qualityVSAvoidcontamination and fluid obstruction

Core Design Contradiction:

Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The friction material sheet is divided into multiple friction material segments that are separated from the sheet by cutting. Each segment remains integrally connected to the sheet by at least one tie, allowing for controlled separation and placement onto the core plate, thereby improving separation quality and reducing contamination.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The cutting process creates cleanly scour-cut edges on the friction material segments, ensuring high-quality separation at the cut surfaces. This local quality improvement prevents contamination and lubricant fluid obstruction at the critical interface between segments and core plate.

Inventive Principle:

Principle #3Local quality

2Ease of manufacture

If friction material segments are placed onto the core plate, then the friction facing is formed, but drag torque increases due to poor separation quality

Engineering Contradiction:

Improvefriction facing formationVSAvoiddrag torque

Core Design Contradiction:

Ease of manufactureVSLoss of energy

Solution Approach 1:

The friction material is segmented into discrete pieces that can be precisely placed onto the core plate. This segmentation allows for optimal positioning and reduces parasitic energy loss by ensuring clean separation and proper alignment of friction material segments.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The cutting process parameters are optimized to create cleanly scour-cut edges, changing the surface quality parameter of the friction material segments. This improvement in edge quality reduces drag torque while maintaining ease of manufacture.

Inventive Principle:

Principle #35Parameter changes

3Reliability

If friction material segments are cut with cleanly scour-cut edges, then separation quality and fuel economy improve, but manufacturing complexity increases

Engineering Contradiction:

Improveseparation qualityVSAvoidcutting process complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The friction material segments are cut with cleanly scour-cut edges and remain integrally connected to the sheet by ties before placement. This preliminary action ensures high separation quality and reliability while the ties maintain structural integrity during handling and placement.

Inventive Principle:

Principle #10Preliminary action

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 approach enhances the separation quality of friction facings, reduces drag torque, and improves fuel economy by minimizing contamination and fluid obstruction, leading to improved performance in wet clutch and brake mechanisms.

Implementation Method 1

cutting a pattern of friction material segments into a friction material sheet such that each friction material segment remains integrally connected to the friction material sheet by at least one tie

Methodology Applied

Scientific EffectMechanical cutting:

Implementation Method 2

separating the predetermined number of friction material segments from the friction material sheet, and placing the predetermined number of friction material segments onto the surface of the core plate over the bonding material

Methodology Applied

Scientific EffectMechanical separation and placement:

Implementation Method 3

bonding material is present

Methodology Applied

Scientific EffectAdhesion: Adhesive

Data Source

PatentUS9943938B2Method and apparatus for making a friction plate

Publication Date: 2018.04.17 BORGWARNER INC

AI summary

A method for making a friction plate that includes a core plate and a friction facing is disclosed. The method includes cutting a pattern of friction material segments into a friction material sheet such that each friction material segment remains integrally connected to the friction material sheet, locating a predetermined number of the friction material segments adjacent to a surface of a core plate to which a bonding material is present, separating the friction material segments from the friction material sheet, and placing the friction material segments onto the surface of the core plate over the bonding material. An apparatus for practicing this method is also disclosed.