Electric Disc Brake Reducer With Elastomer Damping for Vibration Control

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Solution Overview

Problem

Existing brake actuator designs face issues with noise, wear, size, fragility, integration complexity, and assembly complexity due to vibrations and axial or lateral bulk, particularly in electric brake actuators for vehicles.

Innovation Solution

A rotary gear reducer with epicyclic gear trains and a damping device made of elastomeric material, arranged between a fixed ring and brake housing, providing radial and axial vibration damping, and featuring radially protruding ribs and axial support collars for sealing and damping.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If a planetary gear train is used to provide high reduction ratio, then force multiplication is improved, but axial and lateral size increases making integration difficult

Engineering Contradiction:
Improveforce multiplicationVSAvoidaxial and lateral size
Core Design Contradiction:
ForceVSVolume of moving object

Solution Approach 1:

The patent implements a nested planetary gear configuration where multiple planetary stages are arranged concentrically, with inner planetary gears positioned within the outer planetary gears. This nesting approach achieves high reduction ratios while minimizing the axial and lateral footprint of the gear train, enabling compact integration into the brake actuator housing.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The patent transitions from a conventional single-stage planetary gear to a multi-stage nested planetary arrangement that exploits three-dimensional space more efficiently. By stacking planetary stages along the radial dimension and utilizing the hollow center region, the design achieves high force multiplication without proportionally increasing the overall volume.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Object-affected harmful factors

If conventional shock absorbers are added to reduce vibrations, then noise and wear are reduced, but device complexity and bulk increase

Engineering Contradiction:
Improvenoise and wear from vibrationsVSAvoidcomplexity and bulk
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent integrates the shock-absorbing function directly into the planetary gear structure by incorporating elastomeric damping elements between the planetary gears and the housing. This merging of structural and damping functions eliminates the need for separate external shock absorbers, reducing overall device complexity and bulk while effectively reducing vibration-induced noise and wear.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent introduces elastomeric material as an intermediary element between the rigid planetary gear components and the housing. This intermediary material absorbs vibrations and shocks while allowing the structural components to maintain their load-bearing function, thereby reducing noise and wear without adding complex damping mechanisms.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Productivity

If multiple ring gears with different tooth counts are used to achieve high reduction, then reduction ratio is improved, but manufacturing precision requirements increase

Engineering Contradiction:
Improvereduction ratioVSAvoidtooth alignment precision
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent modifies the geometric parameters of the planetary gears, specifically the tooth counts and pitch circle diameters, to achieve the desired reduction ratios. By carefully selecting and coordinating these parameters across multiple nested stages, the design achieves high productivity while managing manufacturing precision requirements through standardized modular components.

Inventive Principle:
Principle #35Parameter changes

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

Reduces noise and wear, facilitates compact integration, simplifies assembly, and enhances reliability by effectively damping vibrations, while maintaining force and stroke capacity.

Implementation Method 1

a damping device made at least partly of elastomeric material, which is arranged around said fixed ring or intended to be arranged so, so as to be compressed radially and/or axially between said fixed ring and said brake housing, and thus achieving radial and/or axial vibration damping between said fixed ring and said brake housing

Methodology Applied
Scientific EffectVibration damping: Damping

Data Source

PatentEP4522469B1Electric disc brake actuator with vibration damped differential reducer, components, brake and assembly method
Publication Date: 2026.01.28 ASTEMO FRANCE
  • EP4522469B1 patent drawingFigure 1~2
  • EP4522469B1 patent drawingFigure 3~4
  • EP4522469B1 patent drawingFigure 5~6

AI summary

The invention relates to a rotary drive reduction gear or geared motor within an electric brake actuator. It comprises one or more planetary gear sets (2) parallel or coaxial to the linear actuation direction (500), which are provided with at least one rotationally fixed ring gear (21). This reduction gear comprises a damping device (204) made at least partially of an elastomer material, which is arranged around the fixed ring gear and compressed radially and/or axially between the fixed ring gear and a brake housing (41). Typically, the reduction gear is a differential planetary gearset (2) driven by its sun gear with planet gears (22) meshing simultaneously with the fixed ring gear (21) and a movable ring gear (23). The latter drives the nut of a reversible screw-nut mechanism (3), which produces the linear force. The overall irreversibility is produced by the differential gearset. The invention also relates to a component determined for producing the damper of this reduction gear, to a motor unit including this damper, to a brake and to a method for assembling same.