Damped Wheel Cylinder Mounting for Quieter Drum Brakes

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Drum brakes in vehicles generate noise pollution due to vibrations between the wheel cylinder and the tray, and existing solutions do not completely decouple these vibrations, also increasing the mass and complexity of the brake system.

Innovation Solution

A set including a hydraulic wheel cylinder, an elastic support element with a groove on the support face, and a translation stop element with a throat on the hydraulic input duct, which axially solicits the elastic support to cushion parasitic movements and limit vibrations, while an anti-rotation paw facilitates assembly and reduces parts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a guide element is interposed between the wheel cylinder and the fixed plate to vibratory decouple them, then noise pollution is reduced, but the fixing screw tightening prevents complete vibration and the device complexity increases

Engineering Contradiction:
Improvenoise pollutionVSAvoiddevice complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The guide element is integrated with the fixed plate by being received within a recess formed in the fixed plate, eliminating the need for separate mounting hardware and reducing device complexity while maintaining the vibration decoupling function

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The guide element acts as an intermediary component between the wheel cylinder and the fixed plate, providing vibratory decoupling through its elastic material properties while being recessed into the fixed plate to allow complete vibration without being constrained by external fasteners

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If the guide element is recessed into the fixed plate to allow complete vibration, then the vibration decoupling is improved, but the manufacturing precision requirements increase

Engineering Contradiction:
Improvevibration decouplingVSAvoidmanufacturing precision
Core Design Contradiction:
Object-affected harmful factorsVSManufacturing precision

Solution Approach 1:

The recess is formed only in the specific area of the fixed plate where the guide element needs to be received, allowing vibration decoupling at that local position while maintaining the structural integrity and standard manufacturing tolerances of the rest of the fixed plate

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The fixed plate is segmented into two functional zones: a recessed area that accommodates the guide element for vibration decoupling, and the remaining structural area that maintains standard manufacturing specifications, thereby reducing overall manufacturing precision requirements

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 configuration effectively reduces noise pollution, minimizes the mass of the drum brake, and simplifies the system by reducing the number of parts and manufacturing/assembly complexity, while ensuring secure positioning of the wheel cylinder.

Implementation Method 1

an elastic support element with a groove on the support face... which axially solicits the elastic support to cushion parasitic movements and limit vibrations

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP4150229B1Wheel cylinder damped with respect to the axle flange, drum brake comprising said cylinder and method for assembling said drum brake
Publication Date: 2025.01.29 HITACHI ASTEMO FRANCE
  • EP4150229B1 patent drawingFigure 1
  • EP4150229B1 patent drawingFigure 2~3
  • EP4150229B1 patent drawingFigure 4~6

AI summary

The invention relates to a hydraulic wheel cylinder (6) for a motor vehicle drum brake, comprising: - a groove arranged on a bearing face (7) so as to receive a resilient bearing member provided to be inserted longitudinally between said hydraulic wheel cylinder (6) and the front face of the axle flange, and - a groove (90) arranged on the outer surface of a hydraulic inlet duct (9), protruding from the bearing face (7), so as to receive a translational stop member which is provided to abut against the rear face of the axle flange when said duct (9) protrudes from said rear face. The invention also relates to an assembly or kit comprising said wheel cylinder, a resilient bearing member and a translational stop member provided to engage with said wheel cylinder and the axle flange, a drum brake, and to a method for assembling such drum brake.