Torque Limiter Load Structure for Uniform Friction Pressure

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Solution Overview

Problem

Existing torque limiters in vehicles suffer from non-homogeneous pressure distribution between the pressure plate and friction elements, leading to mechanical and chemical erosion due to ingress of external agents, and imbalance in friction force, which can cause damage to transmission components.

Innovation Solution

A torque limiter design featuring a load device with radially distanced fulcrums and support sections that apply pressure evenly across the pressure plate, using Belleville springs to ensure balanced friction force and prevent ingress of external agents.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single fulcrum is used in the load device, then the structure is simpler, but the pressure distribution between the pressure plate and friction elements becomes non-homogeneous

Engineering Contradiction:
Improveload device structureVSAvoidpressure distribution
Core Design Contradiction:
Device complexityVSStress or pressure

Solution Approach 1:

The load device is segmented into multiple fulcrums (first fulcrum and second fulcrum) that are radially distanced from each other. This segmentation allows the load to be distributed across multiple contact points on the pressure plate, creating a more homogeneous pressure distribution between the pressure plate and friction elements, thereby resolving the contradiction between structural simplicity and pressure uniformity.

Inventive Principle:
Principle #1Segmentation

2Device complexity

If pressure is concentrated at one point, then the load device structure is simpler, but external agents can ingress into voids causing mechanical and chemical erosion

Engineering Contradiction:
Improvepressure generation mechanismVSAvoidingress of external agents
Core Design Contradiction:
Device complexityVSObject-affected harmful factors

Solution Approach 1:

By using multiple radially distanced fulcrums, the pressure plate maintains continuous contact with the friction elements across multiple zones. This eliminates voids between the pressure plate and friction elements where water, sand, and similar external agents could ingress, preventing mechanical and chemical erosion while maintaining structural simplicity.

Inventive Principle:
Principle #1Segmentation

3Force

If non-homogeneous pressure distribution occurs, then the friction force becomes unbalanced, but achieving homogeneous pressure requires more complex load device design

Engineering Contradiction:
Improvefriction force balanceVSAvoidload device structure
Core Design Contradiction:
ForceVSDevice complexity

Solution Approach 1:

The load device incorporates multiple fulcrums positioned at different radial locations on the pressure plate. This segmentation creates multiple pressure zones that collectively achieve homogeneous pressure distribution across the entire contact surface, ensuring balanced friction force between the pressure plate and friction elements without requiring overly complex mechanisms.

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

The design achieves homogeneous pressure distribution and balanced friction force, preventing mechanical and chemical erosion, thus protecting transmission components and enhancing system reliability.

Implementation Method 1

A torque limiter design featuring a load device with radially distanced fulcrums and support sections that apply pressure evenly across the pressure plate, using Belleville springs to ensure balanced friction force

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

at least one friction element positioned axially between the pressure plate and the drive plate

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3870871B1A torque limiter with a load device
Publication Date: 2025.08.27 VALEO OTOMOTIV SANAYI & TICARET AS
  • EP3870871B1 patent drawingFigure 1
  • EP3870871B1 patent drawingFigure 1.A
  • EP3870871B1 patent drawingFigure 2

AI summary

The invention is a torque limiter (1) comprising a first cover (70) and a second cover (80) connected by means of rivets (81). There is a drive plate (40) located axially between the first cover (70) and the second cover (80). In a preferred embodiment in the art the first cover (70) and the second cover (80) were adapted for connection to the engine by means of a flywheel. The drive plate (40) was adapted for connection to the input shaft of the gearbox. A load device (60) is positioned axially between the first cover (70) and the drive plate (40). A pressure plate (50) was positioned axially between the load device (60) and the drive plate (40). At least one friction element (41) was positioned between the pressure plate (50) and the drive plate (40). Preferably, at least one friction element (41) was attached to each axial surface of the drive plate (40). The load device (60) comprises a first fulcrum (61) and a second fulcrum (62) in contact with a pressure plate (50). Between the first fulcrum (61) and the second fulcrum (62) there is at least one support section (63) which applies force to the first cover (70). The first fulcrum (61) and the second fulcrum (62) are radially distanced from one another.