MR Hydraulic Damper With Passive Chamber for Adaptive Damping

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Solution Overview

Problem

Passive vehicle suspension dampers are fixed and unresponsive to changing road conditions, while active magnetorheological dampers are costly and require complex control systems with inefficient performance.

Innovation Solution

A hydraulic damper with separate chambers filled with regular working fluid and magnetorheological fluid, featuring a secondary piston assembly with electromagnet coils to control magnetic flux and adjust shear resistance, combined with a compensation chamber filled with gas to manage volume differences and enhance damping characteristics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If magnetorheological fluid is used in active dampers to enable continuous damping control, then damping characteristic adaptability is improved, but cost and mechanical wear increase significantly

Engineering Contradiction:
Improvedamping characteristic adaptabilityVSAvoidmanufacturing cost and complexity
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The damper is divided into two independent working chambers: a first chamber filled with conventional hydraulic fluid and a second chamber filled with magnetorheological fluid. Each chamber operates independently with its own piston assembly, allowing the system to combine the benefits of passive damping (low cost, high reliability) with active controllable damping (adaptability) without requiring the entire system to use expensive MR fluid and complex control mechanisms.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A magnetic coupling mechanism acts as an intermediary between the two chambers, transmitting force from the MR fluid chamber to the conventional fluid chamber without direct mechanical contact. This allows the controllable damping force generated by the MR fluid to be transmitted to the main suspension system while avoiding direct exposure of mechanical valve assemblies to abrasive MR fluid particles.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If magnetorheological fluid with suspended magnetic particles is used, then damping control capability is improved, but wear and tear of mechanical valve assemblies increases

Engineering Contradiction:
Improvedamping control capabilityVSAvoidmechanical component reliability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The damper is divided into two independent working chambers: a first chamber filled with conventional hydraulic fluid and a second chamber filled with magnetorheological fluid. Each chamber operates independently with its own piston assembly, allowing the system to combine the benefits of passive damping (low cost, high reliability) with active controllable damping (adaptability) without requiring the entire system to use expensive MR fluid and complex control mechanisms.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A magnetic coupling mechanism acts as an intermediary between the two chambers, transmitting force from the MR fluid chamber to the conventional fluid chamber without direct mechanical contact. This allows the controllable damping force generated by the MR fluid to be transmitted to the main suspension system while avoiding direct exposure of mechanical valve assemblies to abrasive MR fluid particles.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Adaptability or versatility

If complex control systems with numerous sensors are equipped to continuously control magnetorheological dampers, then damping responsiveness is improved, but system complexity and cost increase

Engineering Contradiction:
Improvedamping responsivenessVSAvoidcontrol system complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The damper is divided into two independent working chambers: a first chamber filled with conventional hydraulic fluid and a second chamber filled with magnetorheological fluid. Each chamber operates independently with its own piston assembly, allowing the system to combine the benefits of passive damping (low cost, high reliability) with active controllable damping (adaptability) without requiring the entire system to use expensive MR fluid and complex control mechanisms.

Inventive Principle:
Principle #1Segmentation

4Ease of manufacture

If passive dampers with constant viscosity working fluid are used, then manufacturing simplicity is maintained, but damping characteristic responsiveness to changing road conditions deteriorates

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoiddamping characteristic responsiveness
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The damper is divided into two independent working chambers: a first chamber filled with conventional hydraulic fluid and a second chamber filled with magnetorheological fluid. Each chamber operates independently with its own piston assembly, allowing the system to combine the benefits of passive damping (low cost, high reliability) with active controllable damping (adaptability) without requiring the entire system to use expensive MR fluid and complex control 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 solution provides a cost-effective and simple method to control damping characteristics dynamically, responding to road conditions with improved efficiency and reduced wear on mechanical components.

Implementation Method 1

at least one electromagnet coil for variably generating a magnetic flux modifying shear resistance of magnetorheological fluid to control the flow of magnetorheological fluid passing through said flow channel

Methodology Applied
Scientific EffectMagnetorheological effect: Magnetorheological Fluid

Implementation Method 2

a compensation chamber, distal to the main piston assembly and filed with gas

Methodology Applied
Scientific EffectGas compression and expansion: Compression

Data Source

PatentEP3771845B1Magnetorheological hydraulic damper with passive damping chamber
Publication Date: 2024.09.11 BEIJING WEST IND CO LTD
  • EP3771845B1 patent drawingFigure 1
  • EP3771845B1 patent drawingFigure 2
  • EP3771845B1 patent drawingFigure 3~5

AI summary

The invention relates to a hydraulic damper, comprising a main tube, and a main piston assembly attached to a piston rod. Said piston rod is provided with an annular chamber in which a slidable partition is disposed dividing this chamber into a magnetorheological chamber, and a compensation chamber, wherein said hydraulic damper further comprises a secondary piston assembly slidably disposed inside said magnetorheological chamber, attached to a secondary piston rod, dividing said magnetorheological chamber into a magnetorheological compression chamber, distal to the main piston assembly, and a magnetorheological rebound chamber, proximal to the main piston assembly, wherein said secondary piston assembly is provided with a flow channel and at least one electromagnet coil for variably generating a magnetic flux modifying shear resistance of magnetorheological fluid, wherein said at least one electromagnet coil is connected with a control cable passing through said secondary piston rod and led outside the hydraulic damper.