Wet Disk Clutch Friction Grooves for Drag Torque Tuning

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Solution Overview

Problem

Existing disk clutches, particularly wet-running disk clutches, face challenges in effectively adjusting the drag torque and coefficient of friction, with current methods of recess and groove design providing limited influence on these parameters.

Innovation Solution

The disk clutch design incorporates two types of recesses and/or grooves on the friction surfaces, created through different manufacturing methods, allowing for targeted adjustment of drag torque and coefficient of friction by varying the ratio of these features.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If recesses and/or grooves are provided in friction surfaces with specific dimensioning and shapes, then drag torque can be reduced, but the influence on drag torque and coefficient of friction is limited

Engineering Contradiction:
Improvedrag torqueVSAvoidadjustment range of drag torque and coefficient of friction
Core Design Contradiction:
Loss of energyVSAdaptability or versatility

Solution Approach 1:

The friction surface is segmented into multiple recesses and/or grooves with different dimensions, shapes, and distributions. This segmentation allows each recess/groove to contribute differently to drag torque reduction, providing a broader range of adjustment and more precise control over the friction characteristics compared to uniform designs.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the friction surface are equipped with recesses and/or grooves having locally optimized properties (different depths, widths, spacing, and patterns). This local quality variation enables targeted adjustment of drag torque and coefficient of friction in specific areas, achieving superior overall performance and greater adaptability.

Inventive Principle:
Principle #3Local quality

2Force

If recesses and/or grooves are provided in friction surfaces, then coefficient of friction can be influenced, but the adjustment capability is limited

Engineering Contradiction:
Improvecoefficient of frictionVSAvoidadjustment range of coefficient of friction
Core Design Contradiction:
ForceVSAdaptability or versatility

Solution Approach 1:

The recesses and/or grooves are designed with dynamic characteristics that allow the coefficient of friction to be adjusted based on operating conditions. By varying the geometry (depth, width, spacing) and distribution of recesses/grooves, the friction surface adapts to different sliding speeds and loads, providing a wider adjustment range for the coefficient of friction.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

Multiple parameters of the recesses and/or grooves (depth, width, spacing, pattern, orientation) are varied to achieve different friction characteristics. This multi-parameter optimization enables precise control over the coefficient of friction across a broader range than single-parameter designs, enhancing adaptability.

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If uniform recesses and/or grooves are used in friction surfaces, then manufacturing is simplified, but durability is not optimally increased

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoiddurability of disks
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The friction surface is divided into multiple recesses and/or grooves with varied geometries, which can be manufactured using standardized machining or molding processes. This segmentation approach maintains manufacturing simplicity while allowing optimization of each recess/groove's contribution to durability through controlled variations in their dimensions and distributions.

Inventive Principle:
Principle #1Segmentation

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 enables precise control over drag torque and coefficient of friction, enhancing the durability and operational performance of the disk clutch.

Implementation Method 1

a so-called drag torque occurs when the clutch is open, which is traced back to a fluid, for example, coolant or lubricant, flowing between the friction surfaces

Methodology Applied
Scientific EffectFluid flow: Convection

Implementation Method 2

The disks of the two disk sets may be brought into frictional engagement with one another via friction surfaces

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3625471B1Disk clutch, disk for such a disk clutch, method for producing such a disk clutch or disk
Publication Date: 2025.10.22 BORGWARNER INC
  • EP3625471B1 patent drawingFigure 1~2
  • EP3625471B1 patent drawingFigure 3
  • EP3625471B1 patent drawingFigure 4

AI summary

The present invention relates to a disk clutch comprising a first disk set (32) which is connected rotationally fixed to a first disk carrier (18) and a second disk set (42) which is connected rotationally fixed to a second disk carrier (24), wherein the disks (34 through 40, 46 through 52) of the two disk sets (32, 42) may be brought into frictional engagement with one another via friction surfaces (54, 56), wherein recesses and/or grooves are provided in at least one or more friction surfaces (54, 56) of the disks (34 through 40; 46 through 52) of the first and/or second disk sets (32; 42). A first type of recesses and/or grooves (68) is thereby provided, which is generated by a material shaping and/or a material casting and/or a non-material removing first manufacturing method, and a second type of recesses and/or grooves (70) is provided, which is generated by a material removing second manufacturing method. In addition, the present invention relates to a disk (66) for such a disk clutch and a method for producing such a disk clutch (2) and such a disk (66).