Pneumatic Clutch Release Cleaning Chamber Against Abrasive Ingress

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Solution Overview

Problem

The existing pneumatic central release mechanisms in motor vehicles are prone to contamination from clutch abrasion, which reduces the service life of plain bearings and pneumatic seals due to inadequate protection against abrasive debris.

Innovation Solution

A self-cleaning mechanism is introduced, where a cleaning chamber with fluid pressure greater than or equal to the ambient pressure is created, using a ventilation channel to maintain excess pressure and prevent contaminants from entering, and a filter is used to prevent particles from re-entering.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If dust seals are used to protect the central release bearing, then some protection against particles is provided, but clutch abrasion still penetrates and reaches the pneumatic seals and plain bearings, reducing their service life

Engineering Contradiction:
Improveprotection against clutch abrasionVSAvoidservice life of pneumatic seals and plain bearings
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The invention divides the central release bearing into two separate pressure zones: a first pressure zone (cleaning chamber) and a second pressure zone (pressure chamber). This segmentation allows independent pressure control in each zone, enabling the cleaning chamber to maintain positive pressure relative to the environment to prevent contaminant ingress, while the pressure chamber operates at higher pressure for clutch actuation. The segmentation effectively isolates the pneumatic seals and plain bearings from clutch abrasion.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention introduces a cleaning chamber as an intermediary zone between the external environment and the internal components (pneumatic seals and plain bearings). This intermediary chamber maintains positive pressure to actively prevent clutch abrasion and contaminants from reaching the protected components, serving as a buffer zone that enhances protection beyond what dust seals alone can provide.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If a cleaning chamber with fluid pressure greater than ambient pressure is introduced, then contaminants are prevented from entering, but the device complexity increases

Engineering Contradiction:
Improveingress of clutch abrasionVSAvoidstructure of central release bearing
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The invention merges the cleaning chamber function with the existing pressure chamber structure of the central release bearing. The cleaning chamber is integrated into the housing and utilizes the same pneumatic actuation system, combining two functions (cleaning/protection and pressure actuation) into a unified structure. This reduces the overall complexity compared to adding a completely separate protection system.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The first pressure chamber (cleaning chamber) serves multiple functions: it acts as a protective barrier against contaminants, maintains positive pressure to prevent ingress of clutch abrasion, and can be integrated with the pneumatic actuation system. This multi-functionality reduces the need for separate protection mechanisms, thereby reducing overall device complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 design effectively prevents contaminants from entering the protected components, increasing the service life of pneumatic seals and plain bearings, allowing for either longer durability or reduced material costs.

Implementation Method 1

the fluid pressure within the cleaning chamber is at least temporarily greater than the ambient pressure, but in any case at least equal to the ambient pressure. This prevents contaminants such as clutch wear from entering the cleaning chamber.

Methodology Applied
Scientific EffectFluid pressure: Pressure Increase

Implementation Method 2

With each movement of the release piston, both when engaging and disengaging it, the fluid pressure inside the cleaning chamber increases. This raises the overpressure inside the cleaning chamber relative to the surrounding environment, creating a protective atmosphere.

Methodology Applied
Scientific EffectPressure differential: Pressure Gradient

Implementation Method 3

a filter is used to prevent particles from re-entering

Methodology Applied
Scientific EffectFiltration: Filter (physical)

Data Source

PatentEP3510293B1Self-cleaning mechanism for pneumatic central clutch release
Publication Date: 2024.01.10 KNORR BREMSE SYSTEME FUER NUTZFAHIZEUGE GMBH
  • EP3510293B1 patent drawingFigure 1
  • EP3510293B1 patent drawingFigure 2~3
  • EP3510293B1 patent drawingFigure 4

AI summary

The invention relates to a self-cleaning mechanism for a pneumatic central clutch release, comprising: a release piston (16) which is coaxially arranged around a hollow shaft (14) and is mounted such that it moves in the direction of an axis (A) of the hollow shaft (14); and a housing (15) which at least partially surrounds the release piston (16) so as to form a pressure chamber (31) between the hollow shaft (14), the housing (15) and the release piston (16), which is sealed from the environment and can be connected to a fluid pressure source (60); a cleaning chamber (32) being fluidically arranged between the pressure chamber (31) and the environment, said cleaning chamber being able to be connected to the environment by means of a ventilation channel (40, 50).